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Sample records for study leu-mo fuel

  1. Greenfield Alternative Study LEU-Mo Fuel Fabrication Facility

    SciTech Connect

    Washington Division of URS

    2008-07-01

    This report provides the initial “first look” of the design of the Greenfield Alternative of the Fuel Fabrication Capability (FFC); a facility to be built at a Greenfield DOE National Laboratory site. The FFC is designed to fabricate LEU-Mo monolithic fuel for the 5 US High Performance Research Reactors (HPRRs). This report provides a pre-conceptual design of the site, facility, process and equipment systems of the FFC; along with a preliminary hazards evaluation, risk assessment as well as the ROM cost and schedule estimate.

  2. Fuels characterization studies. [jet fuels

    NASA Technical Reports Server (NTRS)

    Seng, G. T.; Antoine, A. C.; Flores, F. J.

    1980-01-01

    Current analytical techniques used in the characterization of broadened properties fuels are briefly described. Included are liquid chromatography, gas chromatography, and nuclear magnetic resonance spectroscopy. High performance liquid chromatographic ground-type methods development is being approached from several directions, including aromatic fraction standards development and the elimination of standards through removal or partial removal of the alkene and aromatic fractions or through the use of whole fuel refractive index values. More sensitive methods for alkene determinations using an ultraviolet-visible detector are also being pursued. Some of the more successful gas chromatographic physical property determinations for petroleum derived fuels are the distillation curve (simulated distillation), heat of combustion, hydrogen content, API gravity, viscosity, flash point, and (to a lesser extent) freezing point.

  3. Low conversion ratio fuel studies.

    SciTech Connect

    Smith, M. A.

    2006-02-28

    Recent studies on TRU disposition in fast reactors indicated viable reactor performance for a sodium cooled low conversion ratio reactor design. Additional studies have been initiated to refine the earlier work and consider the feasibility of alternate fuel forms such as nitride and oxide fuel (rather than metal fuel). These alternate fuel forms may have significant impacts upon the burner design and the safety behavior. The work performed thus far has focused on compiling the necessary fuel form property information and refinement of the physics models. For this limited project, the burner design and performance using nitride fuel will be assessed.

  4. Spent fuel receipt scenarios study

    SciTech Connect

    Ballou, L.B.; Montan, D.N.; Revelli, M.A.

    1990-09-01

    This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs.

  5. Photomicrographic Studies of Fuel Sprays

    NASA Technical Reports Server (NTRS)

    Lee, Dana W; Spencer, Robert C

    1934-01-01

    A large number of photomicrographs of fuel sprays were taken for the purpose of studying the spray structure and the process of spray formation. They were taken at magnifying powers of 2.5, 3.25, and 10, using a spark discharge of very short duration for illumination. Several types and sizes of nozzles were investigated, different liquids were used, and a wide range of injection pressures was employed. The sprays were photographed as they were injected into a glass-walled chamber in which the air density was varied from 14 atmospheres to 0.0013 atmosphere.

  6. Review of Transmutation Fuel Studies

    SciTech Connect

    Jon Carmack; Kemal O. Pasamehmetoglu

    2008-01-01

    The technology demonstration element of the Global Nuclear Energy Partnership (GNEP) program is aimed at demonstrating the closure of the fuel cycle by destroying the transuranic (TRU) elements separated from spent nuclear fuel (SNF). Multiple recycle through fast reactors is used for burning the TRU initially separated from light-water reactor (LWR) spent nuclear fuel. For the initial technology demonstration, the preferred option to demonstrate the closed fuel cycle destruction of TRU materials is a sodium-cooled fast reactor (FR) used as burner reactor. The sodium-cooled fast reactor represents the most mature sodium reactor technology available today. This report provides a review of the current state of development of fuel systems relevant to the sodium-cooled fast reactor. This report also provides a review of research and development of TRU-metal alloy and TRU-oxide composition fuels. Experiments providing data supporting the understanding of minor actinide (MA)-bearing fuel systems are summarized and referenced.

  7. Fuel quality/processing study. Volume 3: Fuel upgrading studies

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Bruggink, P.; Sinnett, C.

    1981-01-01

    The methods used to calculate the refinery selling prices for the turbine fuels of low quality are described. Detailed descriptions and economics of the upgrading schemes are included. These descriptions include flow diagrams showing the interconnection between processes and the stream flows involved. Each scheme is in a complete, integrated, stand alone facility. Except for the purchase of electricity and water, each scheme provides its own fuel and manufactures, when appropriate, its own hydrogen.

  8. Fuel quality processing study, volume 1

    NASA Technical Reports Server (NTRS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  9. Fuel quality processing study, volume 1

    NASA Astrophysics Data System (ADS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Syverson, H. T.; Klumpe, H. W.; Kessler, R. E.; Kotzot, H. T.; Loran, B. L.

    1981-04-01

    A fuel quality processing study to provide a data base for an intelligent tradeoff between advanced turbine technology and liquid fuel quality, and also, to guide the development of specifications of future synthetic fuels anticipated for use in the time period 1985 to 2000 is given. Four technical performance tests are discussed: on-site pretreating, existing refineries to upgrade fuels, new refineries to upgrade fuels, and data evaluation. The base case refinery is a modern Midwest refinery processing 200,000 BPD of a 60/40 domestic/import petroleum crude mix. The synthetic crudes used for upgrading to marketable products and turbine fuel are shale oil and coal liquids. Of these syncrudes, 50,000 BPD are processed in the existing petroleum refinery, requiring additional process units and reducing petroleum feed, and in a new refinery designed for processing each syncrude to produce gasoline, distillate fuels, resid fuels, and turbine fuel, JPGs and coke. An extensive collection of synfuel properties and upgrading data was prepared for the application of a linear program model to investigate the most economical production slate meeting petroleum product specifications and turbine fuels of various quality grades. Technical and economic projections were developed for 36 scenarios, based on 4 different crude feeds to either modified existing or new refineries operated in 2 different modes to produce 7 differing grades of turbine fuels. A required product selling price of turbine fuel for each processing route was calculated. Procedures and projected economics were developed for on-site treatment of turbine fuel to meet limitations of impurities and emission of pollutants.

  10. High-freezing-point fuel studies

    NASA Technical Reports Server (NTRS)

    Tolle, F. F.

    1980-01-01

    Considerable progress in developing the experimental and analytical techniques needed to design airplanes to accommodate fuels with less stringent low temperature specifications is reported. A computer technique for calculating fuel temperature profiles in full tanks was developed. The computer program is being extended to include the case of partially empty tanks. Ultimately, the completed package is to be incorporated into an aircraft fuel tank thermal analyser code to permit the designer to fly various thermal exposure patterns, study fuel temperatures versus time, and determine holdup.

  11. PEM fuel cell durability studies

    SciTech Connect

    Borup, Rodney L; Davey, John R; Ofstad, Axel B; Xu, Hui

    2008-01-01

    The durability of polymer electrolyte membrane (PEM) fuel cells is a major barrier to the commercialization for stationary and transportation power applications. For transportation applications, the durability target for fuel cell power systems is a 5,000 hour lifespan and able to function over a range of vehicle operating conditions (-40{sup o} to +40{sup o}C). However, durability is difficult to quantify and improve because of the quantity and duration of testing required, and also because the fuel cell stack contains many components, for which the degradation mechanisms, component interactions and effects of operating conditions are not fully understood. These requirements have led to the development of accelerated testing protocols for PEM fuel cells. The need for accelerated testing methodology is exemplified by the times required for standard testing to reach their required targets: automotive 5,000 hrs = {approx} 7 months; stationary systems 40,000 hrs = {approx} 4.6 years. As new materials continue to be developed, the need for relevant accelerated testing increases. In this investigation, we examine the durability of various cell components, examine the effect of transportation operating conditions (potential cycling, variable RH, shut-down/start-up, freeze/thaw) and evaluate durability by accelerated durability protocols. PEM fuel cell durability testing is performed on single cells, with tests being conducted with steady-state conditions and with dynamic conditions using power cycling to simulate a vehicle drive cycle. Component and single-cell characterization during and after testing was conducted to identify changes in material properties and related failure mechanisms. Accelerated-testing experiments were applied to further examine material degradation.

  12. Spent Nuclear Fuel Transport Reliability Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao

    2016-01-01

    This conference paper was orignated and shorten from the following publisehd PTS documents: 1. Jy-An Wang, Hao Jiang, and Hong Wang, Dynamic Deformation Simulation of Spent Nuclear Fuel Assembly and CIRFT Deformation Sensor Stability Investigation, ORNL/SPR-2015/662, November 2015. 2. Jy-An Wang, Hong Wang, Mechanical Fatigue Testing of High-Burnup Fuel for Transportation Applications, NUREG/CR-7198, ORNL/TM-2014/214, May 2015. 3. Jy-An Wang, Hong Wang, Hao Jiang, Yong Yan, Bruce Bevard, Spent Nuclear Fuel Vibration Integrity Study 16332, WM2016 Conference, March 6 10, 2016, Phoenix, Arizona.

  13. External fuel vaporization study, phase 2

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.

    1981-01-01

    An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

  14. Fuel Thermo-physical Characterization Project. Fiscal Year 2014 Final Report

    SciTech Connect

    Burkes, Douglas; Casella, Andrew M.; Buck, Edgar C.; Casella, Amanda J.; Edwards, Matthew K.; MacFarlan, Paul J.; Pool, Karl N.; Slonecker, Bruce D.; Smith, Frances N.; Steen, Franciska H.

    2015-03-15

    The Office of Material Management and Minimization (M3) Reactor Conversion Fuel Thermo-Physical Characterization Project at Pacific Northwest National Laboratory (PNNL) was tasked with using PNNL facilities and processes to receive irradiated low enriched uranium–molybdenum (LEU-Mo) fuel plate samples and perform analysis in support of the M3 Reactor Conversion Program. This work is in support of the M3 Reactor Conversion Fuel Development Pillar that is managed by Idaho National Laboratory. The primary research scope was to determine the thermo-physical properties as a function of temperature and burnup. Work conducted in Fiscal Year (FY) 2014 complemented measurements performed in FY 2013 on four additional irradiated LEU-Mo fuel plate samples. Specifically, the work in FY 2014 investigated the influence of different processing methods on thermal property behavior, the absence of aluminum alloy cladding on thermal property behavior for additional model validation, and the influence of higher operating surface heat flux / more aggressive irradiation conditions on thermal property behavior. The model developed in FY 2013 and refined in FY 2014 to extract thermal properties of the U-Mo alloy from the measurements conducted on an integral fuel plate sample (i.e., U-Mo alloy with a thin Zr coating and clad in AA6061) continues to perform very well. Measurements conducted in FY 2014 on samples irradiated under similar conditions compare well to measurements performed in FY 2013. In general, there is no gross influence of fabrication method on thermal property behavior, although the difference in LEU-Mo foil microstructure does have a noticeable influence on recrystallization of grains during irradiation. Samples irradiated under more aggressive irradiation conditions, e.g., higher surface heat flux, revealed lower thermal conductivity when compared to samples irradiated at moderate surface heat fluxes, with the exception of one sample. This report documents thermal

  15. External fuel vaporization study, phase 1

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.

    1980-01-01

    A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

  16. Accountability study for TMI-2 fuel

    SciTech Connect

    Goris, P; Scott, D D

    1981-05-01

    The TMI-2 accountability study considers problems of identifying, measuring, and accounting for TMI-2 fuel in the resident condition, as it is removed from the reactor, during subsequent cleanup, and during post-removal examinations. The goal is to identify methods and procedures which will provide a verifiable material balance equating to the pre-accident balance.

  17. Fueling studies on the lithium tokamak experiment

    NASA Astrophysics Data System (ADS)

    Lundberg, Daniel Patrick

    Lithium plasma facing components reduce the flux of "recycled" particles entering the plasma edge from the plasma facing components. This results in increased external fueling requirements and provides the opportunity to control the magnitude and distribution of the incoming particle flux. It has been predicted that the plasma density profile will then be determined by the deposition profile of the external fueling, rather than dominated by the recycled particle flux. A series of experiments on the Lithium Tokamak Experiment demonstrate that lithium wall coatings facilitate control of the neutral and plasma particle inventories. With fresh lithium coatings and careful gas injection programming, over 90% of the injected particle inventory can be absorbed in the lithium wall during a discharge. Furthermore, dramatic changes in the fueling requirements and plasma parameters were observed when lithium coatings were applied. This is largely due to the elimination of water as an impurity on the plasma facing components. A Molecular Cluster Injector (MCI) was developed for the fueling of LTX plasmas. The MCI uses a supersonic nozzle, cooled to liquid nitrogen temperatures, to create the conditions necessary for molecular cluster formation. It has been predicted that molecular clusters will penetrate deeper into plasmas than gas-phase molecules via a reduced ionization cross-section and by improving the collimation of the neutral jet. Using an electron beam diagnostic, the densities of the cryogenic MCI are measured to be an order of magnitude higher than in the room-temperature jets formed with the same valve pressure. This indicates increased collimation relative to what would be expected from ideal gas dynamics alone. A systematic study of the fueling efficiencies achieved with the LTX fueling systems is presented. The fueling efficiency of the Supersonic Gas Injector (SGI) is demonstrated to be strongly dependent on the distance between the nozzle and plasma edge. The

  18. Studies and research concerning BNFP: spent fuel dry storage studies at the Barnwell Nuclear Fuel Plant

    SciTech Connect

    Anderson, Kenneth J.

    1980-09-01

    Conceptual designs are presented utilizing the Barnwell Nuclear Fuel Plant for the dry interim storage of spent light water reactor fuel. Studies were conducted to determine feasible approaches to storing spent fuel by methods other than wet pool storage. Fuel that has had an opportunity to cool for several years, or more, after discharge from a reactor is especially adaptable to dry storage since its thermal load is greatly reduced compared to the thermal load immediately following discharge. A thermal analysis was performed to help in determining the feasibility of various spent fuel dry storage concepts. Methods to reject the heat from dry storage are briefly discussed, which include both active and passive cooling systems. The storage modes reviewed include above and below ground caisson-type storage facilities and numerous variations of vault, or hot cell-type, storage facilities.

  19. Coal Integrated Gasification Fuel Cell System Study

    SciTech Connect

    Chellappa Balan; Debashis Dey; Sukru-Alper Eker; Max Peter; Pavel Sokolov; Greg Wotzak

    2004-01-31

    This study analyzes the performance and economics of power generation systems based on Solid Oxide Fuel Cell (SOFC) technology and fueled by gasified coal. System concepts that integrate a coal gasifier with a SOFC, a gas turbine, and a steam turbine were developed and analyzed for plant sizes in excess of 200 MW. Two alternative integration configurations were selected with projected system efficiency of over 53% on a HHV basis, or about 10 percentage points higher than that of the state-of-the-art Integrated Gasification Combined Cycle (IGCC) systems. The initial cost of both selected configurations was found to be comparable with the IGCC system costs at approximately $1700/kW. An absorption-based CO2 isolation scheme was developed, and its penalty on the system performance and cost was estimated to be less approximately 2.7% and $370/kW. Technology gaps and required engineering development efforts were identified and evaluated.

  20. A Study of Fast Reactor Fuel Transmutation in a Candidate Dispersion Fuel Design

    SciTech Connect

    Mark DeHart; Hongbin Zhang; Eric Shaber; Matthew Jesse

    2010-11-01

    Dispersion fuels represent a significant departure from typical ceramic fuels to address swelling and radiation damage in high burnup fuel. Such fuels use a manufacturing process in which fuel particles are encapsulated within a non-fuel matrix. Dispersion fuels have been studied since 1997 as part of an international effort to develop and test very high density fuel types for the Reduced Enrichment for Research and Test Reactors (RERTR) program.[1] The Idaho National Laboratory is performing research in the development of an innovative dispersion fuel concept that will meet the challenges of transuranic (TRU) transmutation by providing an integral fission gas plenum within the fuel itself, to eliminate the swelling that accompanies the irradiation of TRU. In this process, a metal TRU vector produced in a separations process is atomized into solid microspheres. The dispersion fuel process overcoats the microspheres with a mixture of resin and hollow carbon microspheres to create a TRUC. The foam may then be heated and mixed with a metal power (e.g., Zr, Ti, or Si) and resin to form a matrix metal carbide, that may be compacted and extruded into fuel elements. In this paper, we perform reactor physics calculations for a core loaded with the conceptual fuel design. We will assume a “typical” TRU vector and a reference matrix density. We will employ a fuel and core design based on the Advanced Burner Test Reactor (ABTR) design.[2] Using the CSAS6 and TRITON modules of the SCALE system [3] for preliminary scoping studies, we will demonstrate the feasibility of reactor operations. This paper will describe the results of these analyses.

  1. Study of the combustion of various alternate fuels

    SciTech Connect

    Barfield, B.F.; Acker, G.J. Jr.; Lindsay, M.H.

    1984-01-01

    This research project used two methods for studying the problems facing alternate fuels. The first method studied the use of chemicals to improve fuel characteristics without changing the basic engine design. The second method was to make engine modifications to suit characteristics of the alternate fuel. The result of the two methods studied is a two-part report. Alcohols, solvent-refined coal (SRC-II), vegetable oils, and mixtures of these with diesel fuels and with each other are the alternative fuels discussed and tested. 21 references, 4 figures, 10 tables.

  2. Transportation capabilities study of DOE-owned spent nuclear fuel

    SciTech Connect

    Clark, G.L.; Johnson, R.A.; Smith, R.W.; Abbott, D.G.; Tyacke, M.J.

    1994-10-01

    This study evaluates current capabilities for transporting spent nuclear fuel owned by the US Department of Energy. Currently licensed irradiated fuel shipping packages that have the potential for shipping the spent nuclear fuel are identified and then matched against the various spent nuclear fuel types. Also included are the results of a limited investigation into other certified packages and new packages currently under development. This study is intended to support top-level planning for the disposition of the Department of Energy`s spent nuclear fuel inventory.

  3. Feasibility study on AFR-100 fuel conversion from uranium-based fuel to thorium-based fuel

    SciTech Connect

    Heidet, F.; Kim, T.; Grandy, C.

    2012-07-30

    Although thorium has long been considered as an alternative to uranium-based fuels, most of the reactors built to-date have been fueled with uranium-based fuel with the exception of a few reactors. The decision to use uranium-based fuels was initially made based on the technology maturity compared to thorium-based fuels. As a result of this experience, lot of knowledge and data have been accumulated for uranium-based fuels that made it the predominant nuclear fuel type for extant nuclear power. However, following the recent concerns about the extent and availability of uranium resources, thorium-based fuels have regained significant interest worldwide. Thorium is more abundant than uranium and can be readily exploited in many countries and thus is now seen as a possible alternative. As thorium-based fuel technologies mature, fuel conversion from uranium to thorium is expected to become a major interest in both thermal and fast reactors. In this study the feasibility of fuel conversion in a fast reactor is assessed and several possible approaches are proposed. The analyses are performed using the Advanced Fast Reactor (AFR-100) design, a fast reactor core concept recently developed by ANL. The AFR-100 is a small 100 MW{sub e} reactor developed under the US-DOE program relying on innovative fast reactor technologies and advanced structural and cladding materials. It was designed to be inherently safe and offers sufficient margins with respect to the fuel melting temperature and the fuel-cladding eutectic temperature when using U-10Zr binary metal fuel. Thorium-based metal fuel was preferred to other thorium fuel forms because of its higher heavy metal density and it does not need to be alloyed with zirconium to reduce its radiation swelling. The various approaches explored cover the use of pure thorium fuel as well as the use of thorium mixed with transuranics (TRU). Sensitivity studies were performed for the different scenarios envisioned in order to determine the

  4. Detailed studies of aviation fuel flowability

    NASA Technical Reports Server (NTRS)

    Mehta, H. K.; Armstrong, R. S.

    1985-01-01

    Six Jet A fuels, with varying compositions, were tested for low temperature flowability in a 190-liter simulator tank that modeled a section of a wing tank of a wide-body commercial airplane. The insulated tank was chilled by circulating coolant through the upper and lower surfaces. Flow-ability was determined as a function of fuel temperature by holdup, the fraction of unflowable fuel remaining in the tank after otherwise complete withdrawal. In static tests with subfreezing tank conditions, hold up varied with temperature and fuel composition. However, a general correlation of two or three classes of fuel type was obtained by plotting holdup as a function of the difference between freezing point and boundary-layer temperature, measured 0.6 cm above the bottom tank surface. Dynamic conditions of vibrations and slosh or rate of fuel withdrawal had very minor effects on holdup. Tests with cooling schedules to represent extreme, cold-day flights showed, at most, slight holdup for any combination of fuel type or dynamic conditions. Tests that superimposed external fuel heating and recirculation during the cooldown period indicates reduced hold up by modification of the low-temperature boundary layer. Fuel heating was just as effective when initiated during the later times of the tests as when applied continuously.

  5. Stability Study of the RERTR Fuel Microstructure

    SciTech Connect

    Jian Gan; Dennis Keiser; Brandon Miller; Daniel Wachs

    2014-04-01

    The irradiation stability of the interaction phases at the interface of fuel and Al alloy matrix as well as the stability of the fission gas bubble superlattice is believed to be very important to the U-Mo fuel performance. In this paper the recent result from TEM characterization of Kr ion irradiated U-10Mo-5Zr alloy will be discussed. The focus will be on the phase stability of Mo2-Zr, a dominated second phase developed at the interface of U-10Mo and the Zr barrier in a monolithic fuel plate from fuel fabrication. The Kr ion irradiations were conducted at a temperature of 200 degrees C to an ion fluence of 2.0E+16 ions/cm2. To investigate the thermal stability of the fission gas bubble superlattice, a key microstructural feature in both irradiated dispersion U-7Mo fuel and monolithic U-10Mo fuel, a FIB-TEM sample of the irradiated U-10Mo fuel (3.53E+21 fission/cm3) was used for a TEM in-situ heating experiment. The preliminary result showed extraordinary thermal stability of the fission gas bubble superlattice. The implication of the TEM observation from these two experiments on the fuel microstructural evolution under irradiation will be discussed.

  6. Experimental study of external fuel vaporization

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Tevelde, J. A.

    1982-01-01

    The fuel properties used in the design of a flash vaporization system for aircraft gas turbine engines were evaluated in experiments using a flowing system to determine critical temperature and pressure, boiling points, dew points, heat transfer coefficients, deposit formation rates, and deposit removal. Three fuels were included in the experiments: Jet-A, an experimental referree broad specification fuel, and a premium No. 2 diesel fuel. Engine conditions representing a NASA Energy Efficient Engine at sea-level take-off, cruise, and idle were simulated in the vaporization system and it was found that single phase flow was maintained in the heat exchanger and downstream of the throttle. Deposits encountered in the heat exchanger represented a thermal resistance as high as 1300 sq M K/watt and a deposit formation rate over 1000 gC/sq cm hr.

  7. Experimental study of burnout in channels with twisted fuel rods

    NASA Astrophysics Data System (ADS)

    Bol'Shakov, V. V.; Bashkirtsev, S. M.; Kobzar', L. L.; Morozov, A. G.

    2007-05-01

    The results of experimental studies of pressure drop and critical heat flux in the models of fuel assemblies (FAs) with fuel rod simulators twisted relative to the longitudinal axis and a three-ray cross section are considered. The experimental data are compared to the results obtained with the use of techniques adopted for design calculations with fuel rod bundles of type-VVER reactors.

  8. A Parametric Study of the DUPIC Fuel Cycle to Reflect Pressurized Water Reactor Fuel Management Strategy

    SciTech Connect

    Rozon, Daniel; Shen Wei

    2001-05-15

    For both pressurized water reactor (PWR) and Canada deuterium uranium (CANDU) tandem analysis, the Direct Use of spent PWR fuel In CANDU reactor (DUPIC) fuel cycle in a CANDU 6 reactor is studied using the DRAGON/DONJON chain of codes with the ENDF/B-V and ENDF/B-VI libraries. The reference feed material is a 17 x 17 French standard 900-MW(electric) PWR fuel. The PWR spent-fuel composition is obtained from two-dimensional DRAGON assembly transport and depletion calculations. After a number of years of cooling, this defines the initial fuel nuclide field in the CANDU unit cell calculations in DRAGON, where it is further depleted with the same neutron group structure. The resulting macroscopic cross sections are condensed and tabulated to be used in a full-core model of a CANDU 6 reactor to find an optimized channel fueling rate distribution on a time-average basis. Assuming equilibrium refueling conditions and a particular refueling sequence, instantaneous full-core diffusion calculations are finally performed with the DONJON code, from which both the channel power peaking factors and local parameter effects are estimated. A generic study of the DUPIC fuel cycle is carried out using the linear reactivity model for initial enrichments ranging from 3.2 to 4.5 wt% in a PWR. Because of the uneven power histories of the spent PWR assemblies, the spent PWR fuel composition is expected to differ from one assembly to the next. Uneven mixing of the powder during DUPIC fuel fabrication may lead to uncertainties in the composition of the fuel bundle and larger peaking factors in CANDU. A mixing method for reducing composition uncertainties is discussed.

  9. ECAS Phase I fuel cell results. [Energy Conservation Alternatives Study

    NASA Technical Reports Server (NTRS)

    Warshay, M.

    1978-01-01

    This paper summarizes and discusses the fuel cell system results of Phase I of the Energy Conversion Alternatives Study (ECAS). Ten advanced electric powerplant systems for central-station baseload generation using coal were studied by NASA in ECAS. Three types of low-temperature fuel cells (solid polymer electrolyte, SPE, aqueous alkaline, and phosphoric acid) and two types of high-temperature fuel cells (molten carbonate, MC, and zirconia solid electrolyte, SE) were studied. The results indicate that (1) overall efficiency increases with fuel cell temperature, and (2) scale-up in powerplant size can produce a significant reduction in cost of electricity (COE) only when it is accompanied by utilization of waste fuel cell heat through a steam bottoming cycle and/or integration with a gasifier. For low-temperature fuel cell systems, the use of hydrogen results in the highest efficiency and lowest COE. In spite of higher efficiencies, because of higher fuel cell replacement costs integrated SE systems have higher projected COEs than do integrated MC systems. Present data indicate that life can be projected to over 30,000 hr for MC fuel cells, but data are not yet sufficient for similarly projecting SE fuel cell life expectancy.

  10. Fuel Quality/Processing Study. Volume I. Final report

    SciTech Connect

    O'Hara, J B; Bela, A; Jentz, N E; Syverson, H T; Klumpe, H W; Kessler, R E; Kotzot, H T; Loran, B I

    1981-04-01

    This report presents the results of the Fuel Quality/Processing Study project for production of gas turbine fuels. The objective was to provide a data base for establishing intelligent trade-off between advanced turbine technology and liquid fuel quality. Synthetic fuels to be emphasized include those derived from coal and shale. The intent is to use the data base produced to guide the development of specifications for future synthetic liquid fuels anticipated for use in the time period 1985-2000. It is also to be used as a basis for evaluating the value and benefits of federally sponsored R and D efforts in the field of advanced gas turbine technology. The project assessed relative fuel costs, quality and energy efficiency for a number of fuel sources and processing alternatives. An objective was to accelerate implementation of fuel-flexible combustors for industrial and utility stationary gas turbine systems. This is to be accomplished by generating and demonstrating the technology base for development of reliable gas turbine combustors capable of sustained environmentally acceptable operation when using minimally processed synthetic fuels. The key program results are summarized for the following subject areas: literature survey, on-site fuel pretreatment, existing refineries to upgrade fuels, new refineries to upgrade fuels, and environmental considerations. An inhouse linear programming model served as the basis for determining economic processing paths for the existing refineries and new refineries syncrude upgrading. This involved development of extensive input data comprised of fuel properties, yields, component blending characteristics, incremental capital and operating costs, feed and product costs. Economics are based on March 1980 price levels.

  11. Can fuel cells compete? A study of the competition

    SciTech Connect

    Hooie, D.T.; Parsons, E.L.

    1996-12-31

    As fuel cells enter the early stages of commercialization, other manufacturers and packages of power generation equipment are beginning see fuel cells as potential competition as well as an opportunity to collaborate to increase market share. Most fuel cell market studies, however, portray fuel cells as being able to compete {open_quotes}because the market opportunity is so large.{close_quotes} This paper addresses what the competition for fuel cells will be in the power generation/cogeneration market segments, how they can collaborate, as well as some of the advantages and disadvantages of each for capturing significant market share. In particular, the advanced gas turbine and tandem cycles will be compared to phosphoric acid, molten carbonate, and solid oxide fuel cells.

  12. Study questions environmental impact of fuel-cell vehicles

    NASA Astrophysics Data System (ADS)

    Stafford, Ned

    2015-09-01

    Fuel-cell electric vehicles are seen by many as an environmentally friendly technology that can reduce greenhousegas emissions by producing no harmful emissions. But a new study has found that overall a fuel cell electric vehicle has about the same negative environmental impact as a luxury sports car.

  13. Filling Knowledge Gaps with Five Fuel Cycle Studies

    SciTech Connect

    Steven J. Piet; Jess Gehin; William Halsey; Temitope Taiwo

    2010-11-01

    During FY 2010, five studies were conducted of technology families’ applicability to various fuel cycle strategies to fill in knowledge gaps in option space and to better understand trends and patterns. Here, a “technology family” is considered to be defined by a type of reactor and by selection of which actinides provide fuel. This report summarizes the higher-level findings; the detailed analyses and results are documented in five individual reports, as follows: • Advanced once through with uranium fuel in fast reactors (SFR), • Advanced once through (uranium fuel) or single recycle (TRU fuel) in high temperature gas cooled reactors (HTGR), • Sustained recycle with Th/U-233 in light water reactors (LWRs), • Sustained recycle with Th/U-233 in molten salt reactors (MSR), and • Several fuel cycle missions with Fusion-Fission Hybrid (FFH). Each study examined how the designated technology family could serve one or more designated fuel cycle missions, filling in gaps in overall option space. Each study contains one or more illustrative cases that show how the technology family could be used to meet a fuel cycle mission, as well as broader information on the technology family such as other potential fuel cycle missions for which insufficient information was available to include with an illustrative case. None of the illustrative cases can be considered as a reference, baseline, or nominal set of parameters for judging performance; the assessments were designed to assess areas of option space and were not meant to be optimized. There is no implication that any of the cases or technology families are necessarily the best way to meet a given fuel cycle mission. The studies provide five examples of 1-year fuel cycle assessments of technology families. There is reasonable coverage in the five studies of the performance areas of waste management and uranium utilization. The coverage of economics, safety, and proliferation resistance and physical protection in

  14. Hybrid rocket fuel combustion and regression rate study

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Ray, R. L.; Anderson, F. A.; Cohen, N. S.

    1992-01-01

    The objectives of this study are to develop hybrid fuels (1) with higher regression rates and reduced dependence on fuel grain geometry and (2) that maximize potential specific impulse using low-cost materials. A hybrid slab window motor system was developed to screen candidate fuels - their combustion behavior and regression rate. Combustion behavior diagnostics consisted of video and high speed motion pictures coverage. The mean fuel regression rates were determined by before and after measurements of the fuel slabs. The fuel for this initial investigation consisted of hydroxyl-terminated polybutadiene binder with coal and aluminum fillers. At low oxidizer flux levels (and corresponding fuel regression rates) the filled-binder fuels burn in a layered fashion, forming an aluminum containing binder/coal surface melt that, in turn, forms into filigrees or flakes that are stripped off by the crossflow. This melt process appears to diminish with increasing oxidizer flux level. Heat transfer by radiation is a significant contributor, producing the desired increase in magnitude and reduction in flow dependency (power law exponent) of the fuel regression rate.

  15. Shipping Cask Studies with MOX Fuel

    SciTech Connect

    Pavlovichev, A.M.

    2001-05-17

    Tasks of nuclear safety assurance for storage and transport of fresh mixed uranium-plutonium fuel of the VVER-1000 reactor are considered in the view of 3 MOX LTAs introduction into the core. The precise code MCU that realizes the Monte Carlo method is used for calculations.

  16. Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Yan, Yong; Bevard, Bruce Balkcom

    2016-01-01

    The objective of this research is to collect dynamic experimental data on spent nuclear fuel (SNF) under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT), the hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL). The collected CIRFT data will be utilized to support ongoing spent fuel modeling activities, and support SNF transportation related licensing issues. Recent testing to understand the effects of hydride reorientation on SNF vibration integrity is also being evaluated. CIRFT results have provided insight into the fuel/clad system response to transportation related loads. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance, Fuel structure contributes to the SNF system stiffness, There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interaction, and SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous. Because of the non-homogeneous composite structure of the SNF system, finite element analyses (FEA) are needed to translate the global moment-curvature measurement into local stress-strain profiles. The detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained directly from a CIRFT system measurement. Therefore, detailed FEA is used to understand the global test response, and that data will also be presented.

  17. Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study

    NASA Astrophysics Data System (ADS)

    Brewer, Nolan W.; Smith, Alistair M. S.; Hatten, Jeffery A.; Higuera, Philip E.; Hudak, Andrew T.; Ottmar, Roger D.; Tinkham, Wade T.

    2013-03-01

    Biomass burning is a significant contributor to atmospheric carbon emissions but may also provide an avenue in which fire-affected ecosystems can accumulate carbon over time, through the generation of highly resistant fire-altered carbon. Identifying how fuel moisture, and subsequent changes in the fire behavior, relates to the production of fire-altered carbon is important in determining how persistent charred residues are following a fire within specific fuel types. Additionally, understanding how mastication (mechanical forest thinning) and fire convert biomass to black carbon is essential for understanding how this management technique, employed in many fire-prone forest types, may influence stand-level black carbon in soils. In this experimental study, 15 masticated fuel beds, conditioned to three fuel moisture ranges, were burned, and production rates of pyrogenic carbon and soot-based black carbon were evaluated. Pyrogenic carbon was determined through elemental analysis of the post-fire residues, and soot-based black carbon was quantified with thermochemical methods. Pyrogenic carbon production rates ranged from 7.23% to 8.67% relative to pre-fire organic carbon content. Black carbon production rates averaged 0.02% in the 4-8% fuel moisture group and 0.05% in the 13-18% moisture group. A comparison of the ratio of black carbon to pyrogenic carbon indicates that burning with fuels ranging from 13% to 15% moisture content resulted in a higher proportion of black carbon produced, suggesting that the precursors to black carbon were indiscriminately consumed at lower fuel moistures. This research highlights the importance of fuel moisture and its role in dictating both the quantity and quality of the carbon produced in masticated fuel beds.

  18. Fuel quality/processing study. Volume 4: On site processing studies

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Cutrone, M.; Doering, H.; Hickey, J.

    1981-01-01

    Fuel treated at the turbine and the turbine exhaust gas processed at the turbine site are studied. Fuel treatments protect the turbine from contaminants or impurities either in the upgrading fuel as produced or picked up by the fuel during normal transportation. Exhaust gas treatments provide for the reduction of NOx and SOx to environmentally acceptable levels. The impact of fuel quality upon turbine maintenance and deterioration is considered. On site costs include not only the fuel treatment costs as such, but also incremental costs incurred by the turbine operator if a turbine fuel of low quality is not acceptably upgraded.

  19. Study of advanced fuel system concepts for commercial aircraft

    NASA Technical Reports Server (NTRS)

    Coffinberry, G. A.

    1985-01-01

    An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broadened property fuels. The DC-10-30 wide-body tri-jet aircraft and the CF6-8OX engine were used as a baseline design for the study. Three advanced systems were considered and were specifically aimed at addressing freezing point, thermal stability and lubricity fuel properties. Actual DC-10-30 routes and flight profiles were simulated by computer modeling and resulted in prediction of aircraft and engine fuel system temperatures during a nominal flight and during statistical one-day-per-year cold and hot flights. Emergency conditions were also evaluated. Fuel consumption and weight and power extraction results were obtained. An economic analysis was performed for new aircraft and systems. Advanced system means for fuel tank heating included fuel recirculation loops using engine lube heat and generator heat. Environmental control system bleed air heat was used for tank heating in a water recirculation loop. The results showed that fundamentally all of the three advanced systems are feasible but vary in their degree of compatibility with broadened-property fuel.

  20. Bioethanol Fuel Production Concept Study: Topline Report

    SciTech Connect

    Marketing Horizons, Inc.

    2001-11-19

    The DOE is in the process of developing technologies for converting plant matter other than feed stock, e.g., corn stover, into biofuels. The goal of this research project was to determine what the farming community thinks of ethanol as a fuel source, and specifically what they think of bioethanol produced from corn stover. This project also assessed the image of the DOE and the biofuels program and determined the perceived barriers to ethanol-from-stover production.

  1. Studies of oscillatory combustion and fuel vaporization

    NASA Technical Reports Server (NTRS)

    Borman, G. L.; Myers, P. S.; Uyehara, O. A.

    1972-01-01

    Research projects involving oscillatory combustion and fuel vaporization are reported. Comparisons of experimental and theoretical droplet vaporization histories under ambient conditions such that the droplet may approach its thermodynamic critical point are presented. Experimental data on instantaneous heat transfer from a gas to a solid surface under conditions of oscillatory pressure with comparisons to an unsteady one-dimensional model are analyzed. Droplet size and velocity distribution in a spray as obtained by use of a double flash fluorescent method were investigated.

  2. Coal Integrated Gasification Fuel Cell System Study

    SciTech Connect

    Gregory Wotzak; Chellappa Balan; Faress Rahman; Nguyen Minh

    2003-08-01

    The pre-baseline configuration for an Integrated Gasification Fuel Cell (IGFC) system has been developed. This case uses current gasification, clean-up, gas turbine, and bottoming cycle technologies together with projected large planar Solid Oxide Fuel Cell (SOFC) technology. This pre-baseline case will be used as a basis for identifying the critical factors impacting system performance and the major technical challenges in implementing such systems. Top-level system requirements were used as the criteria to evaluate and down select alternative sub-systems. The top choice subsystems were subsequently integrated to form the pre-baseline case. The down-selected pre-baseline case includes a British Gas Lurgi (BGL) gasification and cleanup sub-system integrated with a GE Power Systems 6FA+e gas turbine and the Hybrid Power Generation Systems planar Solid Oxide Fuel Cell (SOFC) sub-system. The overall efficiency of this system is estimated to be 43.0%. The system efficiency of the pre-baseline system provides a benchmark level for further optimization efforts in this program.

  3. Study of fuel cell powerplant with heat recovery

    NASA Technical Reports Server (NTRS)

    King, J. M.; Grasso, A. P.; Clausi, J. V.

    1975-01-01

    It was shown that heat can be recovered from fuel cell power plants by replacing the air-cooled heat exchangers in present designs with units which transfer the heat to the integrated utility system. Energy availability for a 40-kW power plant was studied and showed that the total usable energy at rated power represents 84 percent of the fuel lower heating value. The effects of design variables on heat availability proved to be small. Design requirements were established for the heat recovery heat exchangers, including measurement of the characteristics of two candidate fuel cell coolants after exposure to fuel cell operating conditions. A heat exchanger test program was defined to assess fouling and other characteristics of fuel cell heat exchangers needed to confirm heat exchanger designs for heat recovery.

  4. Electrochemical study of natural gas fueled electrodes for low temperature solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Hussain, M. Jafar; Raza, Rizwan; Ahmad, Mukhtar; Ali, Akbar; Ahmad, Imran; Syed, Waqar A. A.; Janjua, Naveed Kausar; Anis-Ur-Rehman, M.; Khan, M. Ajmal; Shahid, Shaukat A.; Abbas, Ghazanfar

    2016-07-01

    Fuel cell is undoubtedly widespread energy conversion technology, which can convert fuel (biogas) energy into electricity. Solid oxide fuel cell (SOFC) is one of the best choices among the fuel cell’s family due to high efficiency and fuel flexibility. In this study, zinc-based nanostructured Mn0.20FexZn0.80-xOδ electrode materials were successfully developed by solid state reaction. The proposed materials have been characterized by XRD and SEM. The electrical conductivities have been examined by four-probe DC method in the temperature range of 300-600∘C, the maximum values were recorded and found to be 12.019 and 5.106 S/cm at natural gas and air atmosphere, respectively. The electrochemical performance has been measured employing NK-SDC electrolyte material and their current density versus voltage and current density versus power density (I-V and I-P characteristics) have been drawn. The maximum power density was found to be 170 mW/cm2 using natural gas as a bio-fuel over a temperature of 600∘C.

  5. Microfluidic platforms and fundamental electrocatalysis studies for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Cohen, Jamie Lee

    The fabrication and testing of a planar membraneless microchannel fuel cell, based on a silicon microchannel, is described in detail. Laminar flow of fuel and oxidant streams, one on top of the other, prevents fuel crossover while allowing ionic transport at the interface between the two solutions. By employing laminar flow, the useful functions of a membrane are retained, while bypassing its inherent limitations. The planar design maximizes the anode and cathode areas, and elimination of the membrane affords broad flexibility in the choice of fuel and oxidant. Fuels including formic acid, methanol, ethanol, sodium borohydride and hydrogen were tested along with oxidants such as oxygen, hydrogen peroxide and potassium permanganate. Steps taken to improve voltage, current density, and overall power output have been addressed, including the testing of a dual electrolyte system and the use of micro-patterned electrode surfaces to enhance fuel utilization. As the complexity of the fuels studied in the microchannel fuel cell increased, it was imperative to characterize these fuels using electrochemical techniques prior to utilization in the fuel cell. The oxidation pathway of the liquid fuel methanol was studied rigorously because of its importance for micro-fuel cell applications. Activation energies for methanol oxidation at a Ptpoly surface were determined using electrochemical techniques, providing a benchmark for the comparison of activation energies of other Pt-based electrocatalysts for methanol oxidation at a given potential. A protocol to obtain Ea values was established in three different electrolytes and experimental parameters that influence the magnitude of these values are discussed in detail. The oxidation pathways of sodium borohydride were also examined at Au, Pt, and Pd surfaces using cyclic voltammetry, chronoamperometry, and rotating disk electrode voltammetry. In addition to studies on bulk Ptpoly surfaces, new bulk intermetallic catalysts were

  6. A study of M85 fuel quality issues

    SciTech Connect

    Wolbach, C.D.; Browning, L.; Laubenheimer, L.; Trujillo, M.; McCormack, M.

    1995-12-31

    Data from fuel quality inspections conducted by the California Energy Commission at M85 dispensing stations indicated that significant contamination of M85 fuel may be arising from the station fuel dispensing equipment. Repeated testing revealed that high conductivity and high color occurred in the first liter of fuel drawn from a dispenser after not being used for more than 6 hours. As the dispenser hose was the most likely culprit for causing the dark color noted in the first liter of fuel, a study was conducted to ascertain the impact of dispenser hoses on M85 fuel quality. Three types of M85 dispenser hose were tested: the standard M85 dispenser hose (Goodyear Maxxim M85), and two experimental Goodyear hoses with nylon inner liners (Nylon Veneer 66 and Nylon Veneer 11). The results indicated that the standard M85 hose contributed significant amounts of plasticizer (phthalates) and filler (zinc oxide) to the M85 fuel, and that this contamination could contribute to fuel filter clogging problems. It was also found that at least one of the experimental hoses (Nylon Veneer 11) demonstrated significantly less contamination potential than the other two. In addition, analyses of FFV sock and in-line fuel filters showed build-up of metal organic salts possibly resulting from fuel additives, metal corrosion and hose plasticizer acting in concert to form filter clogging material. Some additives act as chelating agents for dissolved metals, while plasticizers can create organic acids that together may form metal organic salts. The combination of amines (from additives), organic acids (from dispenser hoses) and metals (from corrosion) seen on clogged filters show strong circumstantial evidence that the synergism between additives, plasticizers and corroded metal ions form filter clogging material.

  7. Advanced supersonic technology concept study: Hydrogen fueled configuration

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.

    1974-01-01

    Conceptual designs of hydrogen fueled supersonic transport configurations for the 1990 time period were developed and compared with equivalent technology Jet A-1 fueled vehicles to determine the economic and performance potential of liquid hydrogen as an alternate fuel. Parametric evaluations of supersonic cruise vehicles with varying design and transport mission characteristics established the basis for selecting a preferred configuration which was then studied in greater detail. An assessment was made of the general viability of the selected concept including an evaluation of costs and environmental considerations, i.e., exhaust emissions and sonic boom characteristics. Technology development requirements and suggested implementation schedules are presented.

  8. Study of fueling requirements for the Engineering Test Reactor

    SciTech Connect

    Ho, S.K.; Perkins, L.J.

    1987-10-16

    An assessment of the fueling requirement for the TIBER Engineering Test Reactor is studied. The neutral shielding pellet ablation model with the inclusion of the effects of the alpha particles is used for our study. The high electron temperature in a reactor-grade plasma makes pellet penetration very difficult. The launch length has to be very large (several tens of meters) in order to avoid pellet breakage due to the low inertial strength of DT ''ice.'' The minimum repetition rate corresponding to the largest allowable pellet, is found to be about 1 Hz. A brief survey is done on the various operational and conceptual pellet injection schemes for plasma fueling. The underlying conclusion is that an alternative fueling scheme of coaxial compact-toroid plasma gun is very likely needed for effective central fueling of reactor-grade plasmas. 16 refs.

  9. Phosphoric acid fuel cell platinum use study

    NASA Technical Reports Server (NTRS)

    Lundblad, H. L.

    1983-01-01

    The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

  10. Phosphoric acid fuel cell platinum use study

    NASA Astrophysics Data System (ADS)

    Lundblad, H. L.

    1983-05-01

    The U.S. Department of Energy is promoting the private development of phosphoric acid fuel cell (PAFC) power plants for terrestrial applications. Current PAFC technology utilizes platinum as catalysts in the power electrodes. The possible repercussions that the platinum demand of PAFC power plant commercialization will have on the worldwide supply and price of platinum from the outset of commercialization to the year 2000 are investigated. The platinum demand of PAFC commercialization is estimated by developing forecasts of platinum use per unit of generating capacity and penetration of PAFC power plants into the electric generation market. The ability of the platinum supply market to meet future demands is gauged by assessing the size of platinum reserves and the capability of platinum producers to extract, refine and market sufficient quantities of these reserves. The size and timing of platinum price shifts induced by the added demand of PAFC commercialization are investigated by several analytical methods. Estimates of these price shifts are then used to calculate the subsequent effects on PAFC power plant capital costs.

  11. Study of Fuel Property Effects Using Future Low Emissions Heavy Duty Truck Engine Hardware

    SciTech Connect

    Li, Sharon

    2000-08-20

    Fuel properties have had substantial impact on engine emissions. Fuel impact varies with engine technology. An assessment of fuel impact on future low emission designs was needed as part of an EMAEPA-API study effort

  12. Feasibility study on the thorium fueled boiling water breeder reactor

    SciTech Connect

    PetrusTakaki, N.

    2012-07-01

    The feasibility of (Th,U)O 2 fueled, boiling water breeder reactor based on conventional BWR technology has been studied. In order to determine the potential use of water cooled thorium reactor as a competitive breeder, this study evaluated criticality, breeding and void reactivity coefficient in response to changes made in MFR and fissile enrichments. The result of the study shows that while using light water as moderator, low moderator to fuel volume ratio (MFR=0.5), it was possible to breed fissile fuel in negative void reactivity condition. However the burnup value was lower than the value of the current LWR. On the other hand, heavy water cooled reactor shows relatively wider feasible breeding region, which lead into possibility of designing a core having better neutronic and economic performance than light water with negative void reactivity coefficient. (authors)

  13. Spent nuclear fuel project design basis capacity study

    SciTech Connect

    Cleveland, K.J.

    1996-09-09

    A parametric study of the Spent Nuclear Fuel Project system capacity is presented. The study was completed using a commercially available software package to develop a summary level model of the major project systems. Alternative configurations, sub-system cycle times, and operating scenarios were tested to identify their impact on total project duration and equipment requirements.

  14. Spent fuel dissolution studies FY 1991 to 1994

    SciTech Connect

    Gray, W.J.; Wilson, C.N.

    1995-12-01

    Dissolution and transport as a result of groundwater flow are generally accepted as the primary mechanisms by which radionuclides from spent fuel placed in a geologic repository could be released to the biosphere. To help provide a source term for performance assessment calculations, dissolution studies on spent fuel and unirradiated uranium oxides have been conducted over the past few years at Pacific Northwest National Laboratory (PNNL) in support of the Yucca Mountain Site Characterization Project. This report describes work for fiscal years 1991 through 1994. The objectives of these studies and the associated conclusions, which were based on the limited number of tests conducted so far, are described in the following subsections.

  15. Gas fueling studies in the PDX tokamak: II

    SciTech Connect

    Dylla, H.F.; Bell, M.G.; Fonck, R.J.; Jaehnig, K.; Kaye, S.M.; Owens, D.K.; Heifetz, D.B.; Schmidt, G.L.

    1984-01-01

    Measurements of the gas fueling characteristics of the PDX tokamak have been extended in parameter range. An earlier study presented the gas fueling efficiency for H/sub 2/ and D/sub 2/ for the standard PDX divertor configurations with a large conductance between the divertor and main plasma chambers. This study presents the observed variations in H/sub 2/, D/sub 2/, and He neutral pressure and ionization light emission for divertor configurations with a restricted conductance between the divertor and main plasma chambers. The restricted conductance improved the divertor/main-chamber compression ratio by more than an order of magnitude. For the same plasma density, gas fueling from the divertor chamber was twice as efficient as fueling from the main chamber. At the highest plasma densities that were investigated, anti n/sub e/ approx. = 4 x 10/sup 13/ cm/sup -3/, a decrease in the plasma temperature in the divertor was indicated by a decrease in the ionization light at the divertor throat for D/sub 2/ and He fueled discharges. These observations are consistent with a Monte-Carlo model of neutral gas transport in the divertor.

  16. Regenerative fuel cell study for satellites in GEO orbit

    NASA Technical Reports Server (NTRS)

    Levy, Alexander; Vandine, Leslie L.; Stedman, James K.

    1987-01-01

    Summarized are the results of a 12-month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application. Emphasis was placed on concepts with the potential for high energy density (W-hr/lb) and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. The first, the integrated design, utilized a configuration in which the fuel cell and electrolysis cells are alternately stacked inside a pressure vessel. Product water is transferred by diffusion during electrolysis and waste heat is conducted through the pressure wall, thus using completely passive means for transfer and control. The second alkaline system, the dedicated design, uses a separate fuel cell and electrolysis stack so that each unit can be optimized in size and weight based on its orbital operating period. The third design was a dual function stack configuration, in which each cell can operate in both fuel cell and electrolysis mode, thus eliminating the need for two separate stacks and associated equipment. Results indicate that using near term technology energy densities between 46 and 52 W-hr/lb can be achieved at efficiencies of 55 percent. System densities of 115 W-hr/lb are contemplated.

  17. Gas fueling studies in the PDX tokamak: II

    NASA Astrophysics Data System (ADS)

    Dylla, H. F.; Bell, M. G.; Fonck, R. J.; Jaehnig, K.; Kaye, S. M.; Owens, D. K.; Heifetz, D. B.; Schmidt, G. L.

    1984-05-01

    Measurements of the gas fueling characteristics of the PDX tokamak have been extended in parameter range. An earlier study presented the gas fueling efficiency for H 2 and D 2 for the standard PDX divertor configurations with a large conductance between the divertor and main plasma chambers. This study presents the observed variations in H 2, D 2 and He neutral pressure and ionization light emission for divertor configurations with a restricted conductance between the divertor and main plasma chambers. The restricted conductance improved the divertor/main-chamber compression ratio by more than an order of magnitude. For the same plasma density, gas fueling from the divertor chamber was twice as efficient as fueling from the main chamber. At the highest plasma densities that were investigated, overlinene ≃ 4 × 10 13cm-3, a decrease in the plasma temperature in the divertor was indicated by a decrease in the ionization light at the divertor throat for D 2 and He fueled discharges. These observations are consistent with a Monte-Carlo model of neutral gas transport in the divertor.

  18. System Losses Study - FIT (Fuel-cycle Integration and Tradeoffs)

    SciTech Connect

    Steven J. Piet; Nick R. Soelberg; Samuel E. Bays; Robert S. Cherry; Denia Djokic; Candido Pereira; Layne F. Pincock; Eric L. Shaber; Melissa C. Teague; Gregory M. Teske; Kurt G. Vedros

    2010-09-01

    This team aimed to understand the broad implications of changes of operating performance and parameters of a fuel cycle component on the entire system. In particular, this report documents the study of the impact of changing the loss of fission products into recycled fuel and the loss of actinides into waste. When the effort started in spring 2009, an over-simplified statement of the objective was “the number of nines” – how would the cost of separation, fuel fabrication, and waste management change as the number of nines of separation efficiency changed. The intent was to determine the optimum “losses” of TRU into waste for the single system that had been the focus of the Global Nuclear Energy Program (GNEP), namely sustained recycle in burner fast reactors, fed by transuranic (TRU) material recovered from used LWR UOX-51 fuel. That objective proved to be neither possible (insufficient details or attention to the former GNEP options, change in national waste management strategy from a Yucca Mountain focus) nor appropriate given the 2009-2010 change to a science-based program considering a wider range of options. Indeed, the definition of “losses” itself changed from the loss of TRU into waste to a generic definition that a “loss” is any material that ends up where it is undesired. All streams from either separation or fuel fabrication are products; fuel feed streams must lead to fuels with tolerable impurities and waste streams must meet waste acceptance criteria (WAC) for one or more disposal sites. And, these losses are linked in the sense that as the loss of TRU into waste is reduced, often the loss or carryover of waste into TRU or uranium is increased. The effort has provided a mechanism for connecting these three Campaigns at a technical level that had not previously occurred – asking smarter and smarter questions, sometimes answering them, discussing assumptions, identifying R&D needs, and gaining new insights. The FIT model has been a

  19. Experimental Study of Turbine Fuel Thermal Stability in an Aircraft Fuel System Simulator

    NASA Technical Reports Server (NTRS)

    Vranos, A.; Marteney, P. J.

    1980-01-01

    The thermal stability of aircraft gas turbines fuels was investigated. The objectives were: (1) to design and build an aircraft fuel system simulator; (2) to establish criteria for quantitative assessment of fuel thermal degradation; and (3) to measure the thermal degradation of Jet A and an alternative fuel. Accordingly, an aircraft fuel system simulator was built and the coking tendencies of Jet A and a model alternative fuel (No. 2 heating oil) were measured over a range of temperatures, pressures, flows, and fuel inlet conditions.

  20. Application of XPS to study electrocatalysts for fuel cells

    NASA Astrophysics Data System (ADS)

    Corcoran, C. J.; Tavassol, H.; Rigsby, M. A.; Bagus, P. S.; Wieckowski, A.

    Analysis of the surface is paramount to understanding the reactivity, selectivity, and catalytic ability of substances. In particular, this understanding is required to make an efficient use of the catalytic surfaces in fuel cells. X-ray photoelectron spectroscopy (XPS) allows determination of changes in the electronic structure for different surface preparation and composition based, mainly, on shifts of the binding energies of core-level electrons. It is also an ideal method that allows identification of the surface or near surface species in relation to fuel cell catalysis. However, the fundamental theoretical concepts, which are used to analyze and interpret XPS spectra are sometimes not correctly understood or correctly applied. In this review, we not only report on XPS operational parameters in use for fuel cell electrocatalysis, but, more significantly, we review and provide rigorous definitions of fundamental concepts used to understand XPS spectra, including the separation of initial and final state effects and the relaxation of valence electrons to screen core-holes. An additional direction of our review is to show the relationships between XPS binding energy shifts and XPS satellite structure with chemical bonding and chemical interactions. However, our primary concern is to provide reviews of representative cases of the application of XPS to solving fuel cell and electrocatalysis-related problems, highlighting progress in this laboratory. We begin with descriptions of essential issues in fuel cell science and with a review of key concepts of XPS. Then, we briefly report on the XPS instrumentation, after which, studies of fundamental importance to electrochemical processes are reviewed. This review includes an overview of complex organic and biological systems in relation to fuel cell electrocatalysis (probed via XPS). We conclude with a discussion of modern developments in XPS methodology.

  1. Electrochemical degradation, kinetics & performance studies of solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Das, Debanjan

    Linear and Non-linear electrochemical characterization techniques and equivalent circuit modelling were carried out on miniature and sub-commercial Solid Oxide Fuel Cell (SOFC) stacks as an in-situ diagnostic approach to evaluate and analyze their performance under the presence of simulated alternative fuel conditions. The main focus of the study was to track the change in cell behavior and response live, as the cell was generating power. Electrochemical Impedance Spectroscopy (EIS) was the most important linear AC technique used for the study. The distinct effects of inorganic components usually present in hydrocarbon fuel reformates on SOFC behavior have been determined, allowing identification of possible "fingerprint" impedance behavior corresponding to specific fuel conditions and reaction mechanisms. Critical electrochemical processes and degradation mechanisms which might affect cell performance were identified and quantified. Sulfur and siloxane cause the most prominent degradation and the associated electrochemical cell parameters such as Gerisher and Warburg elements are applied respectively for better understanding of the degradation processes. Electrochemical Frequency Modulation (EFM) was applied for kinetic studies in SOFCs for the very first time for estimating the exchange current density and transfer coefficients. EFM is a non-linear in-situ electrochemical technique conceptually different from EIS and is used extensively in corrosion work, but rarely used on fuel cells till now. EFM is based on exploring information obtained from non-linear higher harmonic contributions from potential perturbations of electrochemical systems, otherwise not obtained by EIS. The baseline fuel used was 3 % humidified hydrogen with a 5-cell SOFC sub-commercial planar stack to perform the analysis. Traditional methods such as EIS and Tafel analysis were carried out at similar operating conditions to verify and correlate with the EFM data and ensure the validity of the

  2. Architecture Study for a Fuel Depot Supplied from Lunar Assets

    NASA Technical Reports Server (NTRS)

    Perrin, Thomas M.; Casler, James G.

    2016-01-01

    This architecture study sought to determine the optimum architecture for a fuel depot supplied from lunar assets. Four factors - the location of propellant processing (on the Moon or on the depot), the depot location (on the Moon, L1, GEO, or LEO), the propellant transfer location (L1, GEO, or LEO), and the propellant transfer method (bulk fuel or canister exchange) were combined to identify 18 candidate architectures. Two design reference missions (DRMs) - a commercial satellite servicing mission and a Government cargo mission to Mars - created demand for propellants, while a propellant delivery DRM examined supply issues. The study concluded Earth-Moon L1 is the best location for an orbiting depot. For all architectures, propellant boiloff was less than anticipated, and was far overshadowed by delta-v requirements and resulting fuel consumption. Bulk transfer is the most flexible for both the supplier and customer. However, since canister exchange bypasses the transfer of bulk cryogens and necessary chilldown losses, canister exchange shows promise and merits further investigation. Overall, this work indicates propellant consumption and loss is an essential factor in assessing fuel depot architectures.

  3. Fuel salt and container material studies for MOSART transforming system

    SciTech Connect

    Ignatiev, V.; Feynberg, O.; Merzlyakov, A.; Surenkov, A.; Zagnitko, A.; Afonichkin, V.; Bovet, A.; Khokhlov, V.; Subbotin, V.; Gordeev, M.; Panov, A.; Toropov, A.

    2013-07-01

    A study is under progress to examine the feasibility of single stream Molten Salt Actinide Recycling and Transmuting system without and with Th support (MOSART) fuelled with different compositions of actinide tri-fluorides (AnF{sub 3}) from used LWR fuel. New fast-spectrum design options with homogeneous core and fuel salts with high enough solubility for AnF{sub 3} are being examined because of new goals. The flexibility of single fluid MOSART concept with Th support is underlined, particularly, possibility of its operation in self-sustainable mode (Conversion Ratio: CR=1) using different loadings and make up. The paper summarizes the most current status of fuel salt and container material data for the MOSART concept received within ISTC-3749 and ROSATOM-MARS projects. Key physical and chemical properties of various fluoride fuel salts are reported. The issues like salt purification, the electroreduction of U(IV) to U(III) in LiF-ThF{sub 4} and the electroreduction of Yb(III) to Yb(II) in LiF-NaF are detailed.

  4. Transport Studies and Modeling in PEM Fuel Cells

    SciTech Connect

    Mittelsteadt, Cortney K.; Xu, Hui; Brawn, Shelly

    2014-07-30

    This project’s aim was to develop fuel cell components (i.e. membranes, gas-diffusion media (GDM), bipolar plates and flow fields) that possess specific properties (i.e. water transport and conductivity). A computational fluid dynamics model was developed to elucidate the effect of certain parameters on these specific properties. Ultimately, the model will be used to determine sensitivity of fuel cell performance to component properties to determine limiting components and to guide research. We have successfully reached our objectives and achieved most of the milestones of this project. We have designed and synthesized a variety of hydrocarbon block polymer membranes with lower equivalent weight, structure, chemistry, phase separation and process conditions. These membranes provide a broad selection with optimized water transport properties. We have also designed and constructed a variety of devices that are capable of accurately measuring the water transport properties (water uptake, water diffusivity and electro-osmatic drag) of these membranes. These transport properties are correlated to the membranes’ structures derived from X-ray and microscopy techniques to determine the structure-property relationship. We successfully integrated hydrocarbon membrane MEAs with a current distribution board (CBD) to study the impact of hydrocarbon membrane on water transport in fuel cells. We have designed and fabricated various GDM with varying substrate, diffusivity and micro-porous layers (MPL) and characterized their pore structure, tortuosity and hydrophobicity. We have derived a universal chart (MacMullin number as function of wet proofing and porosity) that can be used to characterize various GDM. The abovementioned GDMs have been evaluated in operating fuel cells; their performance is correlated to various pore structure, tortuosity and hydrophobicity of the GDM. Unfortunately, determining a universal relationship between the MacMullin number and these properties

  5. Prospective studies of HTR fuel cycles involving plutonium

    SciTech Connect

    Bonin, B.; Greneche, D.; Carre, F.; Damian, F.; Doriath, J.Y.

    2002-07-01

    High Temperature Gas Cooled reactors (HTRs) are able to accommodate a wide variety of mixtures of fissile and fertile materials without any significant modification of the core design. This flexibility is due to an uncoupling between the parameters of cooling geometry, and the parameters which characterize neutronic optimisation (moderation ratio or heavy nuclide concentration and distribution). Among other advantageous features, an HTR core has a better neutron economy than a LWR because there is much less parasitic capture in the moderator (capture cross section of graphite is 100 times less than the one of water) and in internal structures. Moreover, thanks to the high resistance of the coated particles, HTR fuels are able to reach very high burn-ups, far beyond the possibilities offered by other fuels (except the special case of molten salt reactors). These features make HTRs especially interesting for closing the nuclear fuel cycle and stabilizing the plutonium inventory. A large number of fuel cycle studies are already available today, on 3 main categories of fuel cycles involving HTRs: i) High enriched uranium cycle, based on thorium utilization as a fertile material and HEU as a fissile material; ii) Low enriched uranium cycle, where only LEU is used (from 5% to 12%); iii) Plutonium cycle based on the utilization of plutonium only as a fissile material, with (or without) fertile materials. Plutonium consumption at high burnups in HTRs has already been tested with encouraging results under the DRAGON project and at Peach Bottom. To maximize plutonium consumption, recent core studies have also been performed on plutonium HTR cores, with special emphasis on weapon-grade plutonium consumption. In the following, we complete the picture by a core study for a HTR burning reactor-grade plutonium. Limits in burnup due to core neutronics are investigated for this type of fuel. With these limits in mind, we study in some detail the Pu cycle in the special case of a

  6. Regenerative fuel cell study for satellites in GEO orbit

    NASA Technical Reports Server (NTRS)

    Vandine, Leslie; Gonzalez-Sanabria, Olga; Levy, Alexander

    1987-01-01

    The results of a 12 month study to identify high performance regenerative hydrogen-oxygen fuel cell concepts for geosynchronous satellite application are summarized. Emphasis was placed on concepts with the potential for high energy density and passive means for water and heat management to maximize system reliability. Both polymer membrane and alkaline electrolyte fuel cells were considered, with emphasis on the alkaline cell because of its high performance, advanced state of development, and proven ability to operate in a launch and space environment. Three alkaline system concepts were studied. Results indicate that using near term technology energy densities between 46 and 52 watt-hour/lb can be achieved at efficiencies of 55 percent. Using advanced light weight cell construction which was achieved in experimental cells, composite tankage material for the reactant gases and the reversible stack concept, system energy densities of 115 watt-hours/lb can be projected.

  7. Ablation study of tungsten-based nuclear thermal rocket fuel

    NASA Astrophysics Data System (ADS)

    Smith, Tabitha Elizabeth Rose

    The research described in this thesis has been performed in order to support the materials research and development efforts of NASA Marshall Space Flight Center (MSFC), of Tungsten-based Nuclear Thermal Rocket (NTR) fuel. The NTR was developed to a point of flight readiness nearly six decades ago and has been undergoing gradual modification and upgrading since then. Due to the simplicity in design of the NTR, and also in the modernization of the materials fabrication processes of nuclear fuel since the 1960's, the fuel of the NTR has been upgraded continuously. Tungsten-based fuel is of great interest to the NTR community, seeking to determine its advantages over the Carbide-based fuel of the previous NTR programs. The materials development and fabrication process contains failure testing, which is currently being conducted at MSFC in the form of heating the material externally and internally to replicate operation within the nuclear reactor of the NTR, such as with hot gas and RF coils. In order to expand on these efforts, experiments and computational studies of Tungsten and a Tungsten Zirconium Oxide sample provided by NASA have been conducted for this dissertation within a plasma arc-jet, meant to induce ablation on the material. Mathematical analysis was also conducted, for purposes of verifying experiments and making predictions. The computational method utilizes Anisimov's kinetic method of plasma ablation, including a thermal conduction parameter from the Chapman Enskog expansion of the Maxwell Boltzmann equations, and has been modified to include a tangential velocity component. Experimental data matches that of the computational data, in which plasma ablation at an angle shows nearly half the ablation of plasma ablation at no angle. Fuel failure analysis of two NASA samples post-testing was conducted, and suggestions have been made for future materials fabrication processes. These studies, including the computational kinetic model at an angle and the

  8. Study of advanced fuel system concepts for commercial aircraft and engines

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.; Brewer, G. D.; Byers, W. D.; Fogg, H. W.; Hanks, D. E.; Chirivella, J.

    1983-01-01

    The impact on a commercial transport aircraft of using fuels which have relaxed property limits relative to current commercial jet fuel was assessed. The methodology of the study is outlined, fuel properties are discussed, and the effect of the relaxation of fuel properties analyzed. Advanced fuel system component designs that permit the satisfactory use of fuel with the candidate relaxed properties in the subject aircraft are described. The two fuel properties considered in detail are freezing point and thermal stability. Three candidate fuel system concepts were selected and evaluated in terms of performance, cost, weight, safety, and maintainability. A fuel system that incorporates insulation and electrical heating elements on fuel tank lower surfaces was found to be most cost effective for the long term.

  9. Studies of the mechanisms of turbine fuel instability

    NASA Technical Reports Server (NTRS)

    Daniel, S. R.

    1983-01-01

    The formation of insoluble deposits in a Jet A, a Diesel, and a model fuel (1/10 v/v tetralin/dodecane) was studied. Experiments were conducted using glass containers at 394 K with an air/fuel ratio of 14/1. The effects of addition of ppm levels of various compounds on deposit formation were evaluated. Nitrogen heterocycles were shown to produce a basicity dependent acceleration of deposition. Thiols and thiophene were shown to increase deposition while sulfides and disulfides act as inhibitors. Copper metal and its salts also promote deposition. Results of various instrumental analyses of deposits and development of a high performance liquid chromatographic method for monitoring deposit precursors are discussed.

  10. A Study of Transport Airplane Crash-Resistant Fuel Systems

    NASA Technical Reports Server (NTRS)

    Jones, Lisa (Technical Monitor); Robertson, S. H.; Johnson, N. B.; Hall, D. S.; Rimson, I. J.

    2002-01-01

    This report presents the results of a study, funded by the Federal Aviation Administration (FAA), of transport airplane crash-resistant fuel system (CRFS). The report covers the historical studies related to aircraft crash fires and fuel containment concepts undertaken by the FAA, NASA, and the U.S. Army, which ultimately led to the current state of the art in CRFS technology. It describes the basic research, testing, field investigations and production efforts which have led to the highly successful military CRFS, which has saved many lives and reduced costs of accidents. Current CRFS technology used in transport category airplanes is defined and compared to the available state-of-the-art technology. The report provides information to the FAA and other government organizations which can help them plan their efforts to improve the state of crash fire protection in the transport airplane fleet. The report provides guidance to designers looking for information about CRFS design problems, analysis tools to use for product improvement, and a summary of current and proposed regulations for transport category airplane fuel systems.

  11. A Compact Flexible Pellet Injection System for Fueling Studies

    NASA Astrophysics Data System (ADS)

    Baylor, L. R.; Combs, S. K.; Fehling, D. T.; Fisher, P. W.; Foust, C. R.; Gouge, M. J.; Rasmussen, D. A.

    2000-10-01

    A compact pellet injection system is being designed and built at ORNL to provide a flexible pellet fueling system for studies in magnetic confinement fusion devices. The system known as a ``pellet injector in a suitcase (PIS)'' is a pipe gun device with four barrels that uses a cryocooler for in-situ hydrogenic pellet formation. The system is being built to provide a flexible, low-cost fueling system that can be used on a number of plasma confinement experiments with minimal installation and operation costs. components in the system. It will use both propellant gas and a mechanical punch to accelerate the 1 - 4 mm size pellets to 100-1500 m/s. With the mechanical punch alone a low speed pellet, useful for curved guide tube applications, can be produced with minimal gas load eliminating the need for a large ballast volume. can be independently fired. diagnose the injector. The PIS is a flexible tool for fueling alternative concept devices such as MST and NSTX and for specialized studies in mainline tokamak experiments such as DIII-D and JET. The small size makes installation on such devices more feasible. of the system design and the expected performance will be presented.

  12. Economic study of future aircraft fuels (1970-2000)

    NASA Technical Reports Server (NTRS)

    Alexander, A. D., III

    1972-01-01

    Future aircraft fuels are evaluated in terms of fuel resource availability and pricing, processing methods, and economic projections over the period 1970-2000. Liquefied hydrogen, methane and propane are examined as potential turbine engine aircraft fuels relative to current JP fuel.

  13. Study of catalysis for solid oxide fuel cells and direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Jiang, Xirong

    typical solid oxide electrolyte, with patterned (octadecyltrichlorosilane) ODTS self-assembled monolayers (SAMs), Pt thin films were grown selectively on the SAM-free surface regions. Features with sizes as small as 2 mum were deposited by this combined ALD-muCP method. The micro-patterned Pt structure deposited by area selective ALD was applied to SOFCs as a current collector grid/patterned catalyst. An improvement in the fuel cell performance by a factor of 10 was observed using the Pt current collector grids/patterned catalyst integrated onto cathodic La0.6Sr 0.4Co0.2Fe0.8O3-delta. For possible catalytic anodes in DMFCs employing a 1:1 stoichiometric methanol-water reforming mixture, two strategies were employed in this thesis. One approach is to fabricate skin catalysts, where ALD Pt films of various thicknesses were used to coat sputtered Ru films forming Pt skin catalysts for study of methanol oxidation. Another strategy is to replace or alloy Pt with Ru; for this effort, both dc-sputtering and atomic layer deposition were employed to fabricate Pt-Ru catalysts of various Ru contents. The electrochemical behavior of all of the Pt skin catalysts, the DC co-sputtered Pt-Ru catalysts and the ALD co-deposited Pt-Ru catalysts were evaluated at room temperature for methanol oxidation using cyclic voltammetry and chronoamperometry in highly concentrated 16.6 M MeOH, which corresponds to the stoichiometric fuel that will be employed in next generation DMFCs that are designed to minimize or eliminate methanol crossover. The catalytic activity of sputtered Ru catalysts toward methanol oxidation is strongly enhanced by the ALD Pt overlayer, with such skin layer catalysts displaying superior catalytic activity over pure Pt. For both the DC co-sputtered catalysts and ALD co-deposited catalysts, the electrochemical studies illustrate that the optimal stoichiometry ratio for Pt to Ru is approximately 1:1, which is in good agreement with most literature.

  14. Experimental plan for the fuel-oil study

    SciTech Connect

    Ternes, M.P.; Levins, W.P.; Brown, M.A.

    1992-01-01

    An up-to-date assessment of the Weatherization Assistance Program (WAP) is being performed by the US Department of Energy WAP Division and the Oak Ridge National Laboratory. Five studies form the evaluation. Major goals of the Fuel-Oil Study are to estimate the fuel oil saved by the WAP in the Northeast during the 1990 and 1991 program years, identify and quantify non-energy impacts of the WAP, assess the cost effectiveness of the WAP within this submarket, and assess factors which may cause savings and cost effectiveness to vary. The study will only analyze single-family houses in the nine states in the Northeast census region and will be carried out over two heating seasons (1990 and 1991 WAP program years). A split-winter, pre- and post-weatherization experimental design with a control group will be used. Houses will be monitored over one winter. Energy conservation measures will be installed in the weatherized houses in January of each winter by the local WAP subgrantee. One hundred twenty five weatherized houses and 75 control houses will be monitored over the 1990--1991 winter; a different set of 200 houses will be monitored over the 1991--1992 winter. The houses will be evenly distributed among 25 subgrantees. Space-heating fuel-oil consumption, indoor temperature, and outdoor temperature data will be collected for all houses. Fuel-oil delivery data will be collected for each house monitored over the 1990--1991 winter for at least a year before weatherization. The delivery data will be analyzed to determine if the accuracy of the study can be improved by collecting fuel-oil delivery data on a larger sample of houses over the 1991--1992 winter. Detailed survey information will be obtained on all the houses. This information includes descriptive details of the house and its mechanical systems, details on household size and other demographics, and occupant answers to questions regarding comfort, safety, and operation of their space-heating system and house.

  15. Engineering model system study for a regenerative fuel cell: Study report

    NASA Technical Reports Server (NTRS)

    Chang, B. J.; Schubert, F. H.; Kovach, A. J.; Wynveen, R. A.

    1984-01-01

    Key design issues of the regenerative fuel cell system concept were studied and a design definition of an alkaline electrolyte based engineering model system or low Earth orbit missions was completed. Definition of key design issues for a regenerative fuel cell system include gaseous reactant storage, shared heat exchangers and high pressure pumps. A power flow diagram for the 75 kW initial space station and the impact of different regenerative fuel cell modular sizes on the total 5 year to orbit weight and volume are determined. System characteristics, an isometric drawing, component sizes and mass and energy balances are determined for the 10 kW engineering model system. An open loop regenerative fuel cell concept is considered for integration of the energy storage system with the life support system of the space station. Technical problems and their solutions, pacing technologies and required developments and demonstrations for the regenerative fuel cell system are defined.

  16. Fuel-cell-propelled submarine-tanker-system study

    SciTech Connect

    Court, K E; Kumm, W H; O'Callaghan, J E

    1982-06-01

    This report provides a systems analysis of a commercial Arctic Ocean submarine tanker system to carry fossil energy to markets. The submarine is to be propelled by a modular Phosphoric Acid Fuel Cell system. The power level is 20 Megawatts. The DOE developed electric utility type fuel cell will be fueled with methanol. Oxidant will be provided from a liquid oxygen tank carried onboard. The twin screw submarine tanker design is sized at 165,000 deadweight tons and the study includes costs and an economic analysis of the transport system of 6 ships. The route will be under the polar icecap from a loading terminal located off Prudhoe Bay, Alaska to a transshipment facility postulated to be in a Norwegian fjord. The system throughput of the gas-fed methanol cargo will be 450,000 barrels per day. The total delivered cost of the methanol including well head purchase price of natural gas, methanol production, and shipping would be $25/bbl from Alaska to the US East Coast. Of this, the shipping cost is $6.80/bbl. All costs in 1981 dollars.

  17. Architecture Study for a Fuel Depot Supplied from Lunar Resources

    NASA Technical Reports Server (NTRS)

    Perrin, Thomas M.

    2016-01-01

    Heretofore, discussions of space fuel depots assumed the depots would be supplied from Earth. However, the confirmation of deposits of water ice at the lunar poles in 2009 suggests the possibility of supplying a space depot with liquid hydrogen/liquid oxygen produced from lunar ice. This architecture study sought to determine the optimum architecture for a fuel depot supplied from lunar resources. Four factors - the location of propellant processing (on the Moon or on the depot), the location of the depot (on the Moon or in cislunar space), and if in cislunar space, where (LEO, GEO, or Earth-Moon L1), and the method of propellant transfer (bulk fuel or canister exchange) were combined to identify 18 potential architectures. Two design reference missions (DRMs) - a satellite servicing mission and a cargo mission to Mars - were used to create demand for propellants, while a third DRM - a propellant delivery mission - was used to examine supply issues. The architectures were depicted graphically in a network diagram with individual segments representing the movement of propellant from the Moon to the depot, and from the depot to the customer

  18. Architecture Study for a Fuel Depot Supplied from Lunar Resources

    NASA Technical Reports Server (NTRS)

    Perrin, Thomas M.

    2016-01-01

    Heretofore, discussions of space fuel depots assumed the depots would be supplied from Earth. However, the confirmation of deposits of water ice at the lunar poles in 2009 suggests the possibility of supplying a space depot with liquid hydrogen/liquid oxygen produced from lunar ice. This architecture study sought to determine the optimum architecture for a fuel depot supplied from lunar resources. Four factors - the location of propellant processing (on the Moon or on the depot), the location of the depot (on the Moon, or at L1, GEO, or LEO), the location of propellant transfer (L1, GEO, or LEO), and the method of propellant transfer (bulk fuel or canister exchange) were combined to identify 18 potential architectures. Two design reference missions (DRMs) - a satellite servicing mission and a cargo mission to Mars - were used to create demand for propellants, while a third DRM - a propellant delivery mission - was used to examine supply issues. The architectures were depicted graphically in a network diagram with individual segments representing the movement of propellant from the Moon to the depot, and from the depot to the customer.

  19. A Feasibility and Optimization Study to Design a Nondestructive ATR Fuel Permanent Scanning System to Determine Fuel Burnup

    NASA Astrophysics Data System (ADS)

    Navarro, J.; Ring, T. A.; Nigg, D. W.

    2014-04-01

    The goal of this project was to develop the best available non-destructive technique to determine burnup of the Advanced Test Reactor (ATR) fuels at Idaho National Laboratory, as well as to make a recommendation regarding the feasibility of implementing a permanent fuel scanning system at the ATR canal. The study determined that useful spectra for validation and fuel burnup predictions can be obtained in-situ at the ATR canal using three different detectors. In addition, the study established that calibration curves can be created to predict ATR fuel burnup onsite. The study also established that in order to design a rugged system that can stand the daily operations at the ATR canal a LaBr3 scintillator can be used effectively if deconvolution process is applied to increase the spectra resolution.

  20. A fuel conservation study for transport aircraft utilizing advanced technology and hydrogen fuel

    NASA Technical Reports Server (NTRS)

    Berry, W.; Calleson, R.; Espil, J.; Quartero, C.; Swanson, E.

    1972-01-01

    The conservation of fossil fuels in commercial aviation was investigated. Four categories of aircraft were selected for investigation: (1) conventional, medium range, low take-off gross weight; (2) conventional, long range, high take-off gross weights; (3) large take-off gross weight aircraft that might find future applications using both conventional and advanced technology; and (4) advanced technology aircraft of the future powered with liquid hydrogen fuel. It is concluded that the hydrogen fueled aircraft can perform at reduced size and gross weight the same payload/range mission as conventionally fueled aircraft.

  1. Preliminary Advanced Test Reactor LEU Fuel Conversion Feasibility Study

    SciTech Connect

    G. S. Chang; R. G. Ambrosek

    2005-11-01

    The Advanced Test Reactor (ATR) is a high power density, high neutron flux research reactor operating in the United States. The ATR has large irradiation test volumes located in high flux areas. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth with a maximum unperturbed thermal neutron flux rating of 1.0 x 1015 n/cm2–s. As a result, the ATR is a representative candidate for assessing the necessary modifications and evaluating the subsequent operating effects associated with low-enriched uranium (LEU) fuel conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed for the fuel cycle burnup comparison analysis. Using the current HEU 235U enrichment of 93.0 % as a baseline, an analysis can be performed to determine the LEU uranium density and 235U enrichment required in the fuel meat to yield an equivalent Keff between the HEU core and a LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the 235U loading in the LEU core, such that the differences in Keff between the HEU and LEU core can be minimized for operation at 150 EFPD with a total core power of 115 MW. The Monte-Carlo with ORIGEN-2 (MCWO) method was used to calculate Keff versus EFPDs. The MCWO-calculated results for the LEU case demonstrated adequate excess reactivity such that the LEU core conversion designer should be able to optimize the 235U content of each fuel plate, so that the Keff and relative radial fission heat flux profile are similar to the reference ATR HEU case. However, to demonstrate that the LEU core fuel cycle performance can meet the Upgraded Final Safety Analysis Report (UFSAR) safety requirements, a further study will be required in order to investigate the detailed radial, axial, and azimuthal heat flux profile variations versus EFPDs.

  2. Neutronic study on conversion of SAFARI-1 to LEU silicide fuel

    SciTech Connect

    Ball, G.; Pond, R.; Hanan, N.; Matos, J.

    1995-02-01

    This paper marks the initial study into the technical and economic feasibility of converting the SAFARI-1 reactor in South Africa to LEU silicide fuel. Several MTR assembly geometries and LEU uranium densities have been studied and compared with MEU and HEU fuels. Two factors of primary importance for conversion of SAFARI-1 to LEU fuel are the economy of the fuel cycle and the performance of the incore and excore irradiation positions.

  3. Feasibility study of application of ductless fuel assembly to FBR

    SciTech Connect

    Itoh, K.; Shibahara, I.

    1996-07-01

    Feasibility studies on an application of the ductless fuel concept to an FBR core have been carried out in order to evaluate the basic features of the ductless core, especially in the fields of the thermal-hydraulic aspects and the mechanical behaviors. Regarding thermal-hydraulic aspects, analyses were performed by using a whole core thermal-hydraulic analysis code by making some modification for this study on the PWR code THINC. A small scaled ductless core model was prepared and a hydraulic experiment was carried out to study basic hydraulic characteristics of a ductless core. Core mechanical behaviors were analyzed focusing on the core irradiation bowing aspects and the seismic behaviors. Following features are revealed on the core structural behaviors: (1) the bowing stiffness of the ductless assembly is around 1/5 to 1/10 of that of the duct type assembly; (2) the contact loads between assemblies by the bowing effects are small through core cycles; (3) the damping of the ductless assemblies are so large that the seismic responses are small and the loads between assemblies are small due to occurring many contact points. Through this study it is expected that the concept of the ductless fuel can be applicable to FBR cores from the design view points of thermal-hydraulic and core mechanical behaviors.

  4. Study on the ignition of a fuel droplet in high temperature stagnant gas

    SciTech Connect

    Yoshizawa, Y.; Tomita, M.; Kawada, H.

    1981-07-01

    This study aimed to clarify the effects of the fuel vapor, which had evaporated in advance and formed combustible mixture around the condensed phase, on the ignition of a fuel droplet under the gas dynamic compression. A soap bubble was utilized to make a heterogeneously distributed fuel vapor pocket in oxidizer gas which offered a model of the vapor cloud around the fuel droplet. Induction periods for the onset of strong emission were measured for fuel droplets, and the models and their ignition processes were examined precisely by means of the interferometric measurement of the fuel concentration field.

  5. State Bus Fleet Study Documents Fuel-Saving Measures.

    ERIC Educational Resources Information Center

    Collings, Amy

    1990-01-01

    A demonstration program conducted in 12 New Jersey school districts identified 18 fuel cost-saving opportunities for school bus operation that could save the state an estimated $1.6 million in fuel costs. (MLF)

  6. Feasibility study of fuel grade ethanol plant for Alcohol Fuels of Mississippi, Inc. , Vicksburg, Mississippi

    SciTech Connect

    1981-01-01

    The results are presented of a feasibility study performed to determine the technical and economic viability of constructing an alcohol plant utilizing the N.Y.U. continuous acid hydrolysis process to convert wood wastes to fuel grade alcohol. The following is a summary of the results: (1) The proposed site in the Vicksburg Industrial Foundation Corporation Industrial Park is adequate from all standpoints, for all plant capacities envisioned. (2) Local hardwood sawmills can provide adequate feedstock for the facility. The price per dry ton varies between $5 and $15. (3) Sale of fuel ethanol would be made primarily through local distributors and an adequate market exists for the plant output. (4) With minor modifications to the preparation facilities, other waste cellulose materials can also be utilized. (5) There are no anticipated major environmental, health, safety or socioeconomic risks related to the construction and operation of the proposed facility. (6) The discounted cash flow and rate of return analysis indicated that the smallest capacity unit which should be built is the 16 million gallon per year plant, utilizing cogeneration. This facility has a 3.24 year payback. (7) The 25 million gallon per year plant utilizing cogeneration is an extremely attractive venture, with a zero interest break-even point of 1.87 years, and with a discounted rate of return of 73.6%. (8) While the smaller plant capacities are unattractive from a budgetary viewpoint, a prudent policy would dictate that a one million gallon per year plant be built first, as a demonstration facility. This volume contains process flowsheets and maps of the proposed site.

  7. Feasibility study of fuel grade ethanol plant for Alcohol Fuels of Mississippi, Inc., Vicksburg, Mississippi

    SciTech Connect

    1981-01-01

    The results are presented of a feasibility study performed to determine the technical and economic viability of constructing an alcohol plant utilizing the N.Y.U. continuous acid hydrolysis process to convert wood wastes to fuel grade alcohol. The following is a summary of the results: (1) The proposed site in the Vicksburg Industrial Foundation Corporation Industrial Park is adequate from all standpoints, for all plant capacities envisioned. (2) Local hardwood sawmills can provide adequate feedstock for the facility. The price per dry ton varies between $5 and $15. (3) Sale of fuel ethanol would be made primarily through local distributors and an adequate market exists for the plant output. (4) With minor modifications to the preparation facilities, other waste cellulose materials can also be utilized. (5) There are no anticipated major environmental, health, safety or socioeconomic risks related to the construction and operation of the proposed facility. (6) The discounted cash flow and rate of return analysis indicated that the smallest capacity unit which should be built is the 16 million gallon per year plant, utilizing cogeneration. This facility has a 3.24 year payback. (7) The 25 million gallon per year plant utilizing cogeneration is an extremely attractive venture, with a zero interest break-even point of 1.87 years, and with a discounted rate of return of 73.6%. (8) While the smaller plant capacities are unattractive from budgetary viewpoint, a prudent policy would dictate that a one million gallon per year plant be built first, as a demonstration facility. This volume contains a summary of the environmental, health, safety, and socioeconomic factors involved in the siting, construction and operation of the plant.

  8. Study of fuel systems for LH2-fueled subsonic transport aircraft, volume 1

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Riple, J. C.; Baerst, C. F.; Garmong, G.

    1978-01-01

    Several engine concepts examined to determine a preferred design which most effectively exploits the characteristics of hydrogen fuel in aircraft tanks received major emphasis. Many candidate designs of tank structure and cryogenic insulation systems were evaluated. Designs of all major elements of the aircraft fuel system including pumps, lines, valves, regulators, and heat exchangers received attention. Selected designs of boost pumps to be mounted in the LH2 tanks, and of a high pressure pump to be mounted on the engine were defined. A final design of LH2-fueled transport aircraft was established which incorporates a preferred design of fuel system. That aircraft was then compared with a conventionally fueled counterpart designed to equivalent technology standards.

  9. Fuel economy screening study of advanced automotive gas turbine engines

    NASA Technical Reports Server (NTRS)

    Klann, J. L.

    1980-01-01

    Fuel economy potentials were calculated and compared among ten turbomachinery configurations. All gas turbine engines were evaluated with a continuously variable transmission in a 1978 compact car. A reference fuel economy was calculated for the car with its conventional spark ignition piston engine and three speed automatic transmission. Two promising engine/transmission combinations, using gasoline, had 55 to 60 percent gains over the reference fuel economy. Fuel economy sensitivities to engine design parameter changes were also calculated for these two combinations.

  10. Compatibility Studies of Hydrogen Peroxide and a New Hypergolic Fuel Blend

    NASA Technical Reports Server (NTRS)

    Baldridge, Jennifer; Villegas, Yvonne

    2002-01-01

    Several preliminary materials compatibility studies have been conducted to determine the practicality of a new hypergolic fuel system. Hypergolic fuel ignites spontaneously as the oxidizer decomposes and releases energy in the presence of the fuel. The bipropellant system tested consists of high-test hydrogen peroxide (HTP) and a liquid fuel blend consisting of a hydrocarbon fuel, an ignition enhancer and a transition metal catalyst. In order for further testing of the new fuel blend to take place, some basic materials compatibility and HTP decomposition studies must be accomplished. The thermal decomposition rate of HTP was tested using gas evolution and isothermal microcalorimetry (IMC). Materials were analyzed for compatibility with hydrogen peroxide including a study of the affect welding has on stainless steel elemental composition and its relation to HTP decomposition. Compatibility studies of valve materials in the fuel blend were performed to determine the corrosion resistance of the materials.

  11. Viability study of automobile shredder residue as fuel.

    PubMed

    Edo, Mar; Aracil, Ignacio; Font, Rafael; Anzano, Manuela; Fullana, Andrés; Collina, Elena

    2013-09-15

    Car Fluff samples collected from a shredding plant in Italy were classified based on particle size, and three different size fractions were obtained in this way. A comparison between these size fractions and the original light fluff was made from two different points of view: (i) the properties of each size fraction as a fuel were evaluated and (ii) the pollutants evolved when each size fraction was subjected to combustion were studied. The aim was to establish which size fraction would be the most suitable for the purposes of energy recovery. The light fluff analyzed contained up to 50 wt.% fines (particle size<20 mm). However, its low calorific value and high emissions of polychlorinated dioxins and furans (PCDD/Fs), generated during combustion, make the fines fraction inappropriate for energy recovery, and therefore, landfilling would be the best option. The 50-100 mm fraction exhibited a high calorific value and low PCDD/F emissions were generated when the sample was combusted, making it the most suitable fraction for use as refuse-derived fuel (RDF). Results obtained suggest that removing fines from the original ASR sample would lead to a material product that is more suitable for use as RDF.

  12. Preliminary study: isotopic safeguards techniques (IST) LMFBR fuel cycles

    SciTech Connect

    Persiani, P. J.; Kroc, T. K.

    1980-06-01

    This memorandum presents the preliminary results of the effort to investigate the applicability of isotope correlation techniques (ICT), formulated for the LWR system, to the LMFBR fuel cycle. The detailed isotopic compositional changes with burnup developed for the CRBR was utilized as the reference case. This differs from the usual LMFBR design studies in that the core uranium is natural uranium rather than depleted. Nevertheless, the general isotopic behavior should not differ significantly and does allow an initial insight into the expected behavior of isotopic correlations for the LMFBR power systems such as: the U.K. PFR and reprocessing plant; the French Phenix and Superphenix; and the US reference conceptual design studies (CDS) of homogeneous and heterogeneous LMFBR systems as they are developed.

  13. Experimental Study of Unsupported Nonane fuel Droplet Combustion in Microgravity

    NASA Technical Reports Server (NTRS)

    Callahan, B. J.; Avedisian, C. T.; Hertzog, D. E.; Berkery, J. W.

    1999-01-01

    Soot formation in droplet flames is the basic component of the particulate emission process that occurs in spray combustion. The complexity of soot formation motivates a one-dimensional transport condition which has obvious advantages in modeling. Recent models of spherically symmetric droplet combustion have made this assumption when incorporating such aspects as detailed chemistry and radiation. Interestingly, spherical symmetry does not necessarily restrict the results because it has been observed that the properties of carbon formed in flames are not strongly affected by the nature of the fuel or flaming configuration. What is affected, however, are the forces acting on the soot aggregates and where they are trapped by a balance of drag and thermophoretic forces. The distribution of these forces depends on the transport conditions of the flame. Prior studies of spherical droplet flames have examined the droplet burning history of alkanes, alcohols and aromatics. Data are typically the evolution of droplet, flame, extinction, and soot shell diameters. These data are only now just beginning to find their way into comprehensive numerical models of droplet combustion to test proposed oxidation schemes for fuels such as methanol and heptane. In the present study, we report new measurements on the burning history of unsupported nonane droplets in a convection-free environment to promote spherical symmetry. The far-field gas is atmospheric pressure air at room temperature. The evolution of droplet diameter was measured using high speed cine photography of a spark-ignited, droplet within a confined volume in a drop tower. The initial droplet diameters varied between 0.5 mm and 0.6 mm. The challenge of unsupported droplets is to form, deploy and ignite them with minimal disturbance, and then to keep them in the camera field of view. Because of the difficulty of this undertaking, more sophisticated diagnostics for studying soot than photographic were not used. Supporting

  14. Light water reactor fuel reprocessing: dissolution studies of voloxidized and nonvoloxidized fuel

    SciTech Connect

    Johnson, D.R.; Stone, J.A.

    1980-04-01

    Small-scale tests with irradiated Zircaloy-clad fuels from Robinson, Oconee, Saxton, and Point Beach reactors with burnups from about 200 to 28,000 MWD/MTHM have been made to determine the dissolution behavior of both voloxidized (U{sub 3}O{sub 8}) and nonvoloxidized (UO{sub 2}) fuel. No significant technical problems were encountered in batch-dissolving of either form. Dissolution rates were well-controlled in all tests. Significant characteristics of U{sub 3}O{sub 8} dissolution that differed from UO{sub 2} dissolution included: (1) reduced tritium and ruthenium ({sup 106}Ru) concentrations in product solutions, (2) increased insoluble noble metal fission product residue (about 2.2X greater), and (3) increased insoluble plutonium in the fission product residue. The insoluble plutonium is easily leached from the residue by 10M HNO{sub 3}. The weight of the fission product residue collected from both U{sub 3}O{sub 8} and UO{sub 2} fuels increased aproximately linearly with fuel burnup. A major fraction (>83%) of the {sup 85}Kr was evolved from U{sub 3}O{sub 8} fuel during dissolution rather than voloxidation. The {sup 85}Kr evolution rate was an appropriate monitor of fuel dissolution rate. Virtually all of the {sup 129}I was evolved by air sparging of the dissolver solution during dissolution. 30 tables, 18 figures.

  15. Biomass Fuel Smoke and Tuberculosis: A Case-Control Study.

    PubMed

    Haque, M A; Barman, N; Islam, M T; Mannan, M; Khan, M H; Karim, M R; Rob, M A; Hossain, M A

    2016-01-01

    This case control study was done to ascertain the association between exposures to biomass cooking fuel smoke and pulmonary tuberculosis. Cases were all newly diagnosed pulmonary tuberculosis patients, randomly collected from the Hospital (DOTS centers) Registry from January 2012 to June 2012 from two Upazillas of Sirajganj district, Bangladesh. A home visitation program was done subsequently. Healthy controls were recruited from the neighbourhood of each case through a predefined procedure. Total 276 new pulmonary tuberculosis cases and 276 neighbourhood controls were enrolled. A semi-structured questionnaire containing demographic information, smoking habits, cooking place, kitchen condition, use of biomass fuel for cooking was used for interview. Crude (unadjusted) odd ratios and their corresponding 95% confidence limits for independent variables were determined by binary logistic regression. All significant variables were entered into a multivariate conditional logistic regression model and a final fitted model was determined by backward elimination methods. In univariate analysis, member of a nuclear family {Unadjusted odd ratio (Unadj. OR) 1.570, 95% CI 1.008-2.44)}, having non-formal education (Unadj. OR 2.739, 95% CI 1.219, 6.153) or primary (Unadj. OR 3.407, 95% CI 1.492, 7.782) to secondary level (Unadj. OR 2.392, 95% CI 1.032, 5.544) education, using cow dung (Unadj. OR 3.961, 95% CI 1.267, 12.376) and biomass fuel i.e. plant origin (Unadj. OR 3.382, 95% CI 1.087, 10.518) for cooking, past smoker (Unadj. OR 2.504, 95% CI 1.061, 5.910), using open oven (Unadj. OR 3.109, 95% CI 0.995, 9.716), having small kitchen area (Unadj. OR 0.99, 95% CI 0.989, 0.999) all were significantly associated with tuberculosis. When all significant variables were entered into a multivariate conditional logistic regression model nuclear family {Adjusted odd ratio (Adj OR) 1.808, 95% CI 1.127, 2.9)}, primary level education (Adj OR 2.86, 95% CI 1.23, 6.647) and non formal

  16. Experimental and Modeling Studies of the Combustion Characteristics of Conventional and Alternative Jet Fuels. Final Report

    NASA Technical Reports Server (NTRS)

    Meeks, Ellen; Naik, Chitral V.; Puduppakkam, Karthik V.; Modak, Abhijit; Egolfopoulos, Fokion N.; Tsotsis, Theo; Westbrook, Charles K.

    2011-01-01

    The objectives of this project have been to develop a comprehensive set of fundamental data regarding the combustion behavior of jet fuels and appropriately associated model fuels. Based on the fundamental study results, an auxiliary objective was to identify differentiating characteristics of molecular fuel components that can be used to explain different fuel behavior and that may ultimately be used in the planning and design of optimal fuel-production processes. The fuels studied in this project were Fischer-Tropsch (F-T) fuels and biomass-derived jet fuels that meet certain specifications of currently used jet propulsion applications. Prior to this project, there were no systematic experimental flame data available for such fuels. One of the key goals has been to generate such data, and to use this data in developing and verifying effective kinetic models. The models have then been reduced through automated means to enable multidimensional simulation of the combustion characteristics of such fuels in real combustors. Such reliable kinetic models, validated against fundamental data derived from laminar flames using idealized flow models, are key to the development and design of optimal combustors and fuels. The models provide direct information about the relative contribution of different molecular constituents to the fuel performance and can be used to assess both combustion and emissions characteristics.

  17. JSC Case Study: Fleet Experience with E-85 Fuel

    NASA Technical Reports Server (NTRS)

    Hummel, Kirck

    2009-01-01

    JSC has used E-85 as part of an overall strategy to comply with Presidential Executive Order 13423 and the Energy Policy Act. As a Federal fleet, we are required to reduce our petroleum consumption by 2 percent per year, and increase the use of alternative fuels in our vehicles. With the opening of our onsite dispenser in October 2004, JSC became the second federal fleet in Texas and the fifth NASA center to add E-85 fueling capability. JSC has a relatively small number of GSA Flex Fuel fleet vehicles at the present time (we don't include personal vehicles, or other contractor's non-GSA fleet), and there were no reasonably available retail E-85 fuel stations within a 15-minute drive or within five miles (one way). So we decided to install a small 1000 gallon onsite tank and dispenser. It was difficult to obtain a supplier due to our low monthly fuel consumption, and our fuel supplier contract has changed three times in less than five years. We experiences a couple of fuel contamination and quality control issues. JSC obtained good information on E-85 from the National Ethanol Vehicle Coalition (NEVC). We also spoke with Defense Energy Support Center, (DESC), Lawrence Berkeley Laboratory, and US Army Fort Leonard Wood. E-85 is a liquid fuel that is dispensed into our Flexible Fuel Vehicles identically to regular gasoline, so it was easy for our vehicle drivers to make the transition.

  18. Study of methane fuel for subsonic transport aircraft

    NASA Technical Reports Server (NTRS)

    Carson, L. K.; Davis, G. W.; Versaw, E. F.; Cunnington, G. R., Jr.; Daniels, E. J.

    1980-01-01

    The cost and performance were defined for commercial transport using liquid methane including its fuel system and the ground facility complex required for the processing and storage of methane. A cost and performance comparison was made with Jet A and hydrogen powered aircraft of the same payload and range capability. Extensive design work was done on cryogenic fuel tanks, insulation systems as well as the fuel system itself. Three candidate fuel tank locations were evaluated, i.e., fuselage tanks, wing tanks or external pylon tanks.

  19. Study of Rapid-Regression Liquefying Hybrid Rocket Fuels

    NASA Technical Reports Server (NTRS)

    Zilliac, Greg; DeZilwa, Shane; Karabeyoglu, M. Arif; Cantwell, Brian J.; Castellucci, Paul

    2004-01-01

    A report describes experiments directed toward the development of paraffin-based hybrid rocket fuels that burn at regression rates greater than those of conventional hybrid rocket fuels like hydroxyl-terminated butadiene. The basic approach followed in this development is to use materials such that a hydrodynamically unstable liquid layer forms on the melting surface of a burning fuel body. Entrainment of droplets from the liquid/gas interface can substantially increase the rate of fuel mass transfer, leading to surface regression faster than can be achieved using conventional fuels. The higher regression rate eliminates the need for the complex multi-port grain structures of conventional solid rocket fuels, making it possible to obtain acceptable performance from single-port structures. The high-regression-rate fuels contain no toxic or otherwise hazardous components and can be shipped commercially as non-hazardous commodities. Among the experiments performed on these fuels were scale-up tests using gaseous oxygen. The data from these tests were found to agree with data from small-scale, low-pressure and low-mass-flux laboratory tests and to confirm the expectation that these fuels would burn at high regression rates, chamber pressures, and mass fluxes representative of full-scale rocket motors.

  20. Diesel fuel component contributions to engine emissions and performance: Clean fuel study

    SciTech Connect

    Erwin, J.; Ryan, T.W. III; Moulten, D.S.

    1994-08-01

    The emissions characteristics of diesel engines are dominated by current engine design parameters as long as the fuels conform to the current industry-accepted specifications. The current and future emissions standard, are low enough that the fuel properties and compositions are starting to play a more significant role in meeting the emerging standards. The potential role of the fuel composition has been recognized by state and federal government agencies, and for the first time, fuel specifications have become part of the emissions control legislation. In this work, five different fuel feed and blend stocks were hydrotreated to two levels of sulfur and aromatic content. These materials were then each distilled to seven or eight fractions of congruent boiling points. After this, the raw materials and all of the fractions were characterized by a complement of tests from American Society for Testing and Materials and by hydrocarbon-type analyses. The sample matrix was subjected to a series of combustion bomb and engine tests to determine the ignition, combustion, and emissions characteristics of each of the 80 test materials.

  1. An experimental study on thermal stability of biodiesel fuel

    NASA Astrophysics Data System (ADS)

    Zhu, Yiying

    Biodiesel fuel, as renewable energy, has been used in conventional diesel engines in pure form or as biodiesel/diesel blends for many years. However, thermal stability of biodiesel and biodiesel/diesel blends has been minimally explored. Aimed to shorten this gap, thermal stability of biodiesel is investigated at high temperatures. In this study, batch thermal stressing experiments of biodiesel fuel were performed in stainless steel coils at specific temperature and residence time range from 250 to 425 °C and 3 to 63 minutes, respectively. Evidence of different pathways of biodiesel fuel degradation is demonstrated chromatographically. It was found that biodiesel was stable at 275 °C for a residence time of 8 minutes or below, but the cis-trans isomerization reaction was observed at 28 minutes. Along with isomerization, polymerization also took place at 300 °C at 63 minutes. Small molecular weight products were detected at 350 °C at 33 minutes resulting from pyrolysis reactions and at 360 °C for 33 minutes or above, gaseous products were produced. The formed isomers and dimers were not stable, further decomposition of these compounds was observed at high temperatures. These three main reactions and the temperature ranges in which they occurred are: isomerization, 275--400 °C; polymerization (Diels-Alder reaction), 300--425 °C; pyrolysis reaction, ≥350 °C. The longer residence time and higher temperature resulted in greater decomposition. As the temperature increased to 425 °C, the colorless biodiesel became brownish. After 8 minutes, almost 84% of the original fatty acid methyl esters (FAMEs) disappeared, indicating significant fuel decomposition. A kinetic study was also carried out subsequently to gain better insight into the biodiesel thermal decomposition. A three-lump model was proposed to describe the decomposition mechanism. Based on this mechanism, a reversible first-order reaction kinetic model for the global biodiesel decomposition was shown to

  2. Options Study Documenting the Fast Reactor Fuels Innovative Design Activity

    SciTech Connect

    Jon Carmack; Kemal Pasamehmetoglu

    2010-07-01

    This document provides presentation and general analysis of innovative design concepts submitted to the FCRD Advanced Fuels Campaign by nine national laboratory teams as part of the Innovative Transmutation Fuels Concepts Call for Proposals issued on October 15, 2009 (Appendix A). Twenty one whitepapers were received and evaluated by an independent technical review committee.

  3. Fuel quality-processing study. Volume 2: Literature survey

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.; Amero, R.; Murthy, B.; Cutrone, M.

    1981-01-01

    The validity of initial assumptions about raw materials choices and relevant upgrading processing options was confirmed. The literature survey also served to define the on-site (at the turbine location) options for fuel treatment and exhaust gas treatment. The literature survey also contains a substantial compilation of specification and physical property information about liquid fuel products relevant to industrial gas turbines.

  4. Fuel quality-processing study. Volume 1: Overview and results

    NASA Technical Reports Server (NTRS)

    Jones, G. E., Jr.

    1982-01-01

    The methods whereby the intermediate results were obtained are outlined, and the evaluation of the feasible paths from liquid fossil fuel sources to generated electricity is presented. The segments from which these paths were built are the results from the fuel upgrading schemes, on-site treatments, and exhaust gas treatments detailed in the subsequent volumes. The salient cost and quality parameters are included.

  5. BIOFEAT: Biodiesel fuel processor for a vehicle fuel cell auxiliary power unit. Study of the feed system

    NASA Astrophysics Data System (ADS)

    Sgroi, M.; Bollito, G.; Saracco, G.; Specchia, S.

    An integrated auxiliary power unit (APU) based on a 10 kW e integrated biodiesel fuel processor has been designed and is being developed. Auto-thermal reforming (ATR) and thermal cracking (TC) were considered for converting the fuel into a hydrogen-rich gas suitable for PEM fuel cells. The fuel processor includes also a gas clean-up system that will reduce the carbon monoxide in the primary processor exit gas to below 10 ppm via a new heat-integrated CO clean-up unit, based on the assembly of catalytic heat exchange plates, so as to meet the operational requirements of a PEMFC stack. This article is devoted to the study and selection of the proper feed strategy for the primary fuel processor. Different pre-treatment and feed alternatives (e.g. based on nozzles or simple coils) were devised and tested for the ATR processors, which turned out to be the preferred primary processing route. A nozzle-based strategy was finally selected along with special recommendations about the constituent materials and the operating procedures to be adopted to avoid coking and nozzle corrosion as well as to allow a wide turn down ratio.

  6. Lifetime studies in H2/Br2 fuel cells

    NASA Astrophysics Data System (ADS)

    Barna, G. G.; Frank, S. N.; Teherani, T. H.; Weedon, L. D.

    1984-09-01

    A fully computerized system has been set up for the life testing of H2 electrodes in 48 percent HBr, and of H2/Br2 fuel cells. Given a fuel cell design with dry H2 and no anolyte loop, the prime parameters influencing the operating lifetime are the hydrophobicity of the anode and the electrolyte transport property of the membrane. A systematic optimization of all the parameters has generated fuel cells that have operated for 10,000h at 2 A/sq in., with no significant degradation.

  7. Advanced supersonic technology concept study: Hydrogen fueled configuration, summary report

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.

    1975-01-01

    Conceptual designs of hydrogen fueled supersonic transport configurations for the 1990 time period were developed and compared with equivalent technology Jet A-1 fueled vehicles to determine the economic and performance potential of liquid hydrogen as an alternate fuel. Parametric evaluations of supersonic cruise vehicles with varying design and transport mission characteristics established the basis for selecting a preferred configuration. An assessment was made of the general viability of the selected concept including an evaluation of costs and environmental considerations, i.e., exhaust emissions and sonic boom characteristics. Technology development requirements and suggested implementation schedules are presented.

  8. Studies on fuel spray characteristics in high-pressure environment

    NASA Technical Reports Server (NTRS)

    Shang, H. M.; Kim, Y. M.; Chen, C. P.; Wang, T. S.

    1992-01-01

    The present study deals with several issues involving the improvement of physical submodels and the computational efficiency in modeling dense fuel sprays. To improve the computational efficiency, a parcel PDF approach is implemented which can account for turbulent dispersion within each computational parcel. The advantage of a parcel PDF tracking method is to reduce the number of computational parcels representing the spray dynamics as well as to obtain grid-independent solutions for two-phase flows. To account for the dense spray effects, an existing drop collision and coalescence model, two breakup models, and a Reitz's wave instability model were used. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Comparative performance for two breakup models as well as the turbulence modulation effects are also studied. Validation cases include the nonevaporating and evaporating solid-cone dense sprays. The predictions show a reasonably good agreement with available experimental results in terms of spray penetration, drop sizes, gas and drop mean velocities, and gas and drop rms velocities. The numerical results indicate that the present parcel PDF model has the capability of accurately representing drop dispersion in dense sprays with manageable number of computational parcels.

  9. Studies on fuel spray characteristics in high-pressure environment

    NASA Astrophysics Data System (ADS)

    Shang, H. M.; Kim, Y. M.; Chen, C. P.; Wang, T. S.

    1992-07-01

    The present study deals with several issues involving the improvement of physical submodels and the computational efficiency in modeling dense fuel sprays. To improve the computational efficiency, a parcel PDF approach is implemented which can account for turbulent dispersion within each computational parcel. The advantage of a parcel PDF tracking method is to reduce the number of computational parcels representing the spray dynamics as well as to obtain grid-independent solutions for two-phase flows. To account for the dense spray effects, an existing drop collision and coalescence model, two breakup models, and a Reitz's wave instability model were used. These models were incorporated into a state-of-the-art multiphase all-speed transient flow solution procedure. Comparative performance for two breakup models as well as the turbulence modulation effects are also studied. Validation cases include the nonevaporating and evaporating solid-cone dense sprays. The predictions show a reasonably good agreement with available experimental results in terms of spray penetration, drop sizes, gas and drop mean velocities, and gas and drop rms velocities. The numerical results indicate that the present parcel PDF model has the capability of accurately representing drop dispersion in dense sprays with manageable number of computational parcels.

  10. Thorex solvent extraction studies with irradiated HTGR fuel: series I

    SciTech Connect

    Lamb, C.E.; Mitchell, A.D.; Vaughen, V.C.A.; Shannon, R.J.

    1980-10-01

    A series of solvent extraction experiments to test the first-cycle fuel reprocessing flowsheet, proposed by the General Atomic Company for the Hot Engineering Test Facility, was completed. Using irradiated fuel, the experiments were designed to test the extraction, partition, partition-scrub, and strip operations. Each experiment utilized crosscurrent batch extractions and consecutive stages. Each stage was tested in duplicate. Experimental procedures were developed with synthetic feeds and then were used in a hot cell with radioactive solutions of dissolved irradiated fuel. The analytical measurements for thorium and acid compared favorably with the values predicted by the computer program for solvent extraction processes having interacting solutes (SEPHIS-MOD4). The SEPHIS-MOD4 program was valuable in interpreting this first set of experiments with irradiated fuels. Significant problems were experienced in the analysis for uranium in irradiated solutions. These problems emphasize the need for continued development of new or improved procedures for analyzing highly radioactive materials.

  11. Gas-fueling studies in the PDX tokamak

    SciTech Connect

    Dylla, H.F.; Blanchard, W.R.; Budny, R.; Fonck, R.J.; Owens, D.K.; Schmidt, G.L.

    1982-08-01

    The characteristics of gas-fueling of high power discharges in the PDX tokamak have been investigated using gas-flow, neutral pressure, plasma density, and H..cap alpha.. emission measurements. The efficiency of gas-fueling was measured for various plasma configurations by comparison of the measured gas-influx rates to the particle exhaust rates inferred from particle decay time measurements. We observe that the fueling efficiency decreases significantly with increasing plasma density as the ionization length for thermal neutrals becomes shorter than the width of the boundary plasma. Gas fueling rates required to maintain a given plasma density are considerably higher (by factors of 5 to 10) for diverted discharges compared to limiter discharges. This result is attributed to a lower effective recycling coefficient for diverted plasmas. We discuss the dependence of the particle balance on the following experimentally measured parameters: the particle containment time, system-pumping speed, and neutral pressure in the vicinity of the active pumps.

  12. Gas-fueling studies in the PDX Tokamak

    NASA Astrophysics Data System (ADS)

    Dylla, H. F.; Blanchard, W. R.; Budny, R.; Fonck, R. J.; Owens, D. K.; Schmidt, G. L.

    1982-12-01

    The characteristics of gas-fueling of high power discharges in the PDX tokamak have been investigated using gas-flow, neutral pressure, plasma density, and H α emission measurements. The efficiency of gas-fueling was measured for various plasma configurations by comparison of the measured gas-influx rates to the particle exhaust rates inferred from particle decay time measurements. We observe that the fueling efficiency decreases significantly with increasing plasma density as the ionization lenght for thermal neutrals becomes shorter than the width of the boundary plasma. Gas fueling rates required to maintain a given plasma density are considerably higher (by factors of 5-10) for diverted discharges compared to limiter discharges. This result is attributed to a lower effective recycling coefficient for diverted plasmas. We discuss the dependence of the particle balance on the following experimentally measured parameters: the particle containment time, system pumping speed, and neutral pressure in the vicinity of the active pumps.

  13. Hydrogen production econometric studies. [hydrogen and fossil fuels

    NASA Technical Reports Server (NTRS)

    Howell, J. R.; Bannerot, R. B.

    1975-01-01

    The current assessments of fossil fuel resources in the United States were examined, and predictions of the maximum and minimum lifetimes of recoverable resources according to these assessments are presented. In addition, current rates of production in quads/year for the fossil fuels were determined from the literature. Where possible, costs of energy, location of reserves, and remaining time before these reserves are exhausted are given. Limitations that appear to hinder complete development of each energy source are outlined.

  14. BWR Spent Nuclear Fuel Interfacial Bonding Efficiency Study

    SciTech Connect

    Wang, Jy-An John; Jiang, Hao

    2015-04-30

    The objective of this project is to perform a systematic study of spent nuclear fuel (SNF, also known as “used nuclear fuel” [UNF]) integrity under simulated transportation environments using the Cyclic Integrated Reversible-Bending Fatigue Tester (CIRFT) hot-cell testing technology developed at Oak Ridge National Laboratory (ORNL) in August 2013. Under Nuclear Regulatory Commission (NRC) sponsorship, ORNL completed four benchmark tests, four static tests, and twelve dynamic or cycle tests on H. B. Robinson (HBR) high burn-up (HBU) fuel. The clad of the HBR fuels was made of Zircaloy-4. Testing was continued in fiscal year (FY) 2014 using Department of Energy (DOE) funds. Additional CIRFT testing was conducted on three HBR rods; two specimens failed, and one specimen was tested to over 2.23 × 107 cycles without failing. The data analysis on all the HBR SNF rods demonstrated that it is necessary to characterize the fatigue life of the SNF rods in terms of (1) the curvature amplitude and (2) the maximum absolute of curvature extremes. The maximum extremes are significant because they signify the maximum tensile stress for the outer fiber of the bending rod. CIRFT testing has also addressed a large variation in hydrogen content on the HBR rods. While the load amplitude is the dominant factor that controls the fatigue life of bending rods, the hydrogen content also has an important effect on the lifetime attained at each load range tested. In FY 15, eleven SNF rod segments from the Limerick BWR were tested using the ORNL CIRFT equipment; one test under static conditions and ten tests under dynamic loading conditions. Under static unidirectional loading, a moment of 85 N·m was obtained at a maximum curvature of 4.0 m-1. The specimen did not show any sign of failure during three repeated loading cycles to a similar maximum curvature. Ten cyclic tests were conducted with amplitudes varying from 15.2 to 7.1 N·m. Failure was observed in nine of

  15. Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems

    SciTech Connect

    Leigh R. Martin

    2014-09-01

    This document was prepared to meet FCR&D level 3 milestone M3FT-14IN0304022, “Perform Thermodynamics Measurements on Fuel Cycle Case Study Systems.” This work was carried out under the auspices of the Thermodynamics and Kinetics FCR&D work package. This document reports preliminary work in support of determining the thermodynamic parameters for the ALSEP process. The ALSEP process is a mixed extractant system comprised of a cation exchanger 2-ethylhexyl-phosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) and a neutral solvating extractant N,N,N’,N’-tetraoctyldiglycolamide (TODGA). The extractant combination produces complex organic phase chemistry that is challenging for traditional measurement techniques. To neutralize the complexity, temperature dependent solvent extraction experiments were conducted with neat TODGA and scaled down concentrations of the ALSEP formulation to determine the enthalpies of extraction for the two conditions. A full set of thermodynamic data for Eu, Am, and Cm extraction by TODGA from 3.0 M HNO3 is reported. These data are compared to previous extraction results from a 1.0 M HNO3 aqueous medium, and a short discussion of the mixed HEH[EHP]/TODGA system results is offered.

  16. Experimental Study of the Stability of Aircraft Fuels at Elevated Temperatures

    NASA Technical Reports Server (NTRS)

    Vranos, A.; Marteney, P. J.

    1980-01-01

    An experimental study of fuel stability was conducted in an apparatus which simulated an aircraft gas turbine fuel system. Two fuels were tested: Jet A and Number 2 Home Heating oil. Jet A is an aircraft gas turbine fuel currently in wide use. No. 2HH was selected to represent the properties of future turbine fuels, particularly experimental Reference Broad Specification, which, under NASA sponsorship, was considered as a possible next-generation fuel. Tests were conducted with varying fuel flow rates, delivery pressures and fuel pretreatments (including preheating and deoxygenation). Simulator wall temperatures were varied between 422K and 672K at fuel flows of 0.022 to 0.22 Kg/sec. Coking rate was determined at four equally-spaced locations along the length of the simulator. Fuel samples were collected for infrared analysis. The dependence of coking rate in Jet A may be correlated with surface temperature via an activation energy of 9 to 10 kcal/mole, although the results indicate that both bulk fluid and surface temperature affect the rate of decomposition. As a consequence, flow rate, which controls bulk temperature, must also be considered. Taken together, these results suggest that the decomposition reactions are initiated on the surface and continue in the bulk fluid. The coking rate data for No. 2 HH oil are very highly temperature dependent above approximately 533K. This suggests that bulk phase reactions can become controlling in the formation of coke.

  17. Feasibility study of utilization of degummed soybean oil as a substitute for diesel fuel. Biomass alternative fuels program. Final report

    SciTech Connect

    Not Available

    1981-11-01

    The purpose of this project was to determine the economic and technological feasibility of producing a diesel oil substitute or extender from soybean oil. Existing technology was reviewed, to determine the minimum modification necessary for production of an acceptable fuel product. The information developed indicated that the degummed soybean oil produced by existing processing plants is theoretically suitable for use as a diesel fuel extender. This situation is very favorable to early commercialization of degummed soybean oil as a diesel fuel extender during the 1980's. Moreover, a large energy gain is realized when the soybean oil is utilized as fuel. Its heat of combustion is reported as 16,920 Btu per pound, or 130,000 Btu per gallon. Production of soybean oil consumes between 3000 and 5000 Btu per pound or 23,000 and 39,000 Btu per gallon. A resource availability study disclosed that the southeastern region of the United States produces approximately 260 million bushels of soybeans per year. In the same general area, fourteen extraction plants are operating, with a combined annual capacity of approximately 200 million bushels. Thus, regional production is sufficient to support the extraction capacity. Using an average figure of 1.5 gallons of oil per bushel of soybeans gives annual regional oil production of approximately 300 million gallons. An engine test plan was developed and implemented in this project. Data provide a preliminary indication that the blend containing one-third degummed soybean oil and two-thirds No. 2 diesel oil performed satisfactorily. Long term operation on the 50-50 blend is questionable. Detailed data and observations appear in the body of the report. The study also presents detailed engineering, financial, marketing, management and implementation plans for production of the proposed fuel blend, as well as a complete analysis of impacts. 4 references, 55 figures, 56 tables.

  18. Experimental study of the thermal stability of hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Marteney, P. J.; Colket, M. B.; Vranos, A.

    1982-01-01

    The thermal stability of two hydrocarbon fuels (premium diesel and regular diesel) was determined in a flow reactor under conditions representing operation of an aircraft gas turbine engine. Temperature was varied from 300 to 750 F (422 to 672 K) for fuel flows of 2.84 to 56.8 liters/hr (corresponding to 6.84 x 0.00010 to 1.63 x 0.010 kg/sec for regular diesel fuel and 6.55 x 0.00010 to 1.37 x 0.010 kg/sec for premium diesel fuel); test times varied between 1 and 8 hr. The rate of deposition was obtained through measurement of weight gained by metal discs fixed along the channel wall. The rate of deposit formation is best correlated by an Arrhenius expression. The sample discs in the flow reactor were varied among stainless steel, aluminum and brass; fuels were doped with quinoline, indole, and benzoyl perioxide to yield nitrogen or oxygen concentrations of approximately 1000 ppm. The most substantial change in rate was an increase in deposits for brass discs; other disc materials or the additives caused only small perturbations. Tests were also conducted in a static reactor at temperatures of 300 to 800 F for times of 30 min to 2 1/2 hr. Much smaller deposition was found, indicating the importance of fluid transport in the mechanism.

  19. a Study on Fuel Estimation Algorithms for a Geostationary Communication & Broadcasting Satellite

    NASA Astrophysics Data System (ADS)

    Eun, Jong-Won

    2000-12-01

    It has been developed to calculate fuel budget for a geostationary communication and broadcasting satellite. It is quite essential that the pre-launch fuel budget estimation must account for the deterministic transfer and drift orbit maneuver requirements. After on-station, the calculation of satellite lifetime should be based on the estimation of remaining fuel and assessment of actual performance. These estimations step from the proper algorithms to produce the prediction of satellite lifetime. This paper concentrates on the fuel estimation method that was studied for calculation of the propellant budget by using the given algorithms. Applications of this method are discussed for a communication and broadcasting satellite.

  20. Neutronics Studies of Uranium-bearing Fully Ceramic Micro-encapsulated Fuel for PWRs

    DOE PAGES

    George, Nathan M.; Maldonado, G. Ivan; Terrani, Kurt A.; Godfrey, Andrew T.; Gehin, Jess C.; Powers, Jeffrey J.

    2014-12-01

    Our study evaluated the neutronics and some of the fuel cycle characteristics of using uranium-based fully ceramic microencapsulated (FCM) fuel in a pressurized water reactor (PWR). Specific PWR lattice designs with FCM fuel have been developed that are expected to achieve higher specific burnup levels in the fuel while also increasing the tolerance to reactor accidents. The SCALE software system was the primary analysis tool used to model the lattice designs. A parametric study was performed by varying tristructural isotropic particle design features (e.g., kernel diameter, coating layer thicknesses, and packing fraction) to understand the impact on reactivity and resultingmore » operating cycle length. Moreover, to match the lifetime of an 18-month PWR cycle, the FCM particle fuel design required roughly 10% additional fissile material at beginning of life compared with that of a standard uranium dioxide (UO2) rod. Uranium mononitride proved to be a favorable fuel for the fuel kernel due to its higher heavy metal loading density compared with UO2. The FCM fuel designs evaluated maintain acceptable neutronics design features for fuel lifetime, lattice peaking factors, and nonproliferation figure of merit.« less

  1. Experimental study on spray characteristics of alternate jet fuels using Phase Doppler Anemometry

    NASA Astrophysics Data System (ADS)

    Kannaiyan, Kumaran; Sadr, Reza

    2013-11-01

    Gas-to-Liquid (GTL) fuels have gained global attention due to their cleaner combustion characteristics. The chemical and physical properties of GTL jet fuels are different from conventional jet fuels owing to the difference in their production methodology. It is important to study the spray characteristics of GTL jet fuels as the change of physical properties can affect atomization, mixing, evaporation and combustion process, ultimately affecting emission process. In this work, spray characteristics of two GTL synthetic jet fuels are studied using a pressure-swirl nozzle at different injection pressures and atmospheric ambient condition. Phase Doppler Anemometry (PDA) measurements of droplet size and velocity are compared with those of regular Jet A-1 fuel at several axial and radial locations downstream of the nozzle exit. Experimental results show that although the GTL fuels have different physical properties such as viscosity, density, and surface tension, among each other the resultant change in the spray characteristics is insignificant. Furthermore, the presented results show that GTL fuel spray characteristics exhibit close similarity to those of Jet A-1 fuel. Funded by Qatar Science and Technology Park.

  2. Polyoxymetalate liquid-catalyzed polyol fuel cell and the related photoelectrochemical reaction mechanism study

    NASA Astrophysics Data System (ADS)

    Wu, Weibing; Liu, Wei; Mu, Wei; Deng, Yulin

    2016-06-01

    A novel design of liquid catalyzed fuel cell (LCFC), which uses polyoxometalates (POMs) as the photocatalyst and charge carrier has been reported previously. In this paper, the adaptability of biomass fuels (e.g., glycerol and glucose) to the LCFC and corresponding cell performance were studied in detail here. An interesting finding that greatly differs from conventional fuel cell is that high molecular weight fuels rather than small molecule fuels (e.g., methanol and ethylene glycol) are favored by the novel LCFC with respect to the power densities. The power output of LCFC strongly depends on the number and structure of hydroxyl groups in the biomass fuels. The evidence of UV-Vis and 1H NMR spectra shows that the preassociation between POM and alcohol fuels, which determines the photoelectrochemical reaction pathway of POM, is enhanced as the number of hydroxyl increases. Experimental results also demonstrate that more hydroxyl groups in the molecules lead to faster photoelectrochemical reaction between POM and fuels, higher reduction degree of POM, and further higher power output of LCFC. Our study reveals that biomass-based polyhydroxyl compounds such as starch, hemicellulose and cellulose are potential high-performance fuels for LCFC.

  3. Neutronics Studies of Uranium-bearing Fully Ceramic Micro-encapsulated Fuel for PWRs

    SciTech Connect

    George, Nathan M.; Maldonado, G. Ivan; Terrani, Kurt A.; Godfrey, Andrew T.; Gehin, Jess C.; Powers, Jeffrey J.

    2014-12-01

    Our study evaluated the neutronics and some of the fuel cycle characteristics of using uranium-based fully ceramic microencapsulated (FCM) fuel in a pressurized water reactor (PWR). Specific PWR lattice designs with FCM fuel have been developed that are expected to achieve higher specific burnup levels in the fuel while also increasing the tolerance to reactor accidents. The SCALE software system was the primary analysis tool used to model the lattice designs. A parametric study was performed by varying tristructural isotropic particle design features (e.g., kernel diameter, coating layer thicknesses, and packing fraction) to understand the impact on reactivity and resulting operating cycle length. Moreover, to match the lifetime of an 18-month PWR cycle, the FCM particle fuel design required roughly 10% additional fissile material at beginning of life compared with that of a standard uranium dioxide (UO2) rod. Uranium mononitride proved to be a favorable fuel for the fuel kernel due to its higher heavy metal loading density compared with UO2. The FCM fuel designs evaluated maintain acceptable neutronics design features for fuel lifetime, lattice peaking factors, and nonproliferation figure of merit.

  4. Fuel for the Future: Biodiesel - A Case study

    NASA Astrophysics Data System (ADS)

    Lutterbach, Márcia T. S.; Galvão, Mariana M.

    High crude oil prices, concern over depletion of world reserves, and growing apprehension about the environment, encouraged the search for alternative energy sources that use renewable natural resources to reduce or replace traditional fossil fuels such as diesel and gasoline (Hill et al., 2006). Among renewable fuels, biodiesel has been attracting great interest, especially in Europe and the United States. Biodiesel is defined by the World Customs Organization (WCO) as 'a mixture of mono-alkyl esters of long-chain [C16-C18] fatty acids derived from vegetable oils or animal fats, which is a domestic renewable fuel for diesel engines and which meets the US specifications of ASTM D 6751'. Biodiesel is biodegradable and non toxic, produces 93% more energy than the fossil energy required for its production, reduces greenhouse gas emissions by 40% compared to fossil diesel (Peterson and Hustrulid, 1998; Hill et al., 2006) and stimulates agriculture.

  5. Comparative Study of the Thermal Conductivity of Solid Biomass Fuels

    PubMed Central

    2016-01-01

    The thermal conductivity of solid biomass fuels is useful information in the investigation of biomass combustion behavior and the development of modeling especially in the context of large scale power generation. There are little published data on the thermal conductivity of certain types of biomass such as wheat straw, miscanthus, and torrefied woods. Much published data on wood is in the context of bulk materials. A method for determining the thermal conductivities of small particles of biomass fuels has been developed using a custom built test apparatus. Fourteen different samples of various solid biomass fuel were processed to form a homogenized pellet for analysis. The thermal conductivities of the pelletized materials were determined and compared against each other and to existing data. PMID:27041819

  6. A Comparison Study of Various Nuclear Fuel Cycle Alternatives

    SciTech Connect

    Kwon, Eun-ha; Ko, Won-il

    2007-07-01

    As a nation develops its nuclear strategies, it must consider various aspects of nuclear energy such as sustainability, environmental-friendliness, proliferation-resistance, economics, technologies, and so on. Like all the policy decision, however, a nuclear fuel cycle option can not be superior in all aspects; the nation must identify its top priority and accordingly evaluate all the possible nuclear fuel cycle options. For such a purpose, this paper takes four different fuel cycle options that are likely adopted by the Korean government, considering the current status of nuclear power generation and the 3. Comprehensive Nuclear Energy Promotion Plan (CNEPP) - Once-through Cycle, DUPIC Recycle, Thermal Recycle and GEN-IV Recycle. The paper then evaluates each option in terms of resource utilization and waste generation. The analysis shows that the GEN-IV Recycle appears to be most competitive from these aspects. (authors)

  7. Fuel/engine/airframe tradeoff study, phase 1

    NASA Technical Reports Server (NTRS)

    Peacock, A. T.

    1980-01-01

    The effects of broadening the specifications for JP-4 and JP-8 fueled on the performance and cost of all USAF aircraft presently using JP-4 as well as those expected to be introduced into the force structure by 1983 are investigated. Test results indicated that there was no impact on engine performance, turbine durability, and coking, however there was a small maintenance cost increase as a result of a small combustor life decrease. Using JP-4 as standard fuel will avoid the use of high demand middle distillate fuels and give producers flexibility. Extensive use of JP-8 in the United States will increase middle distillate demand and cause a slight increase in engine hot-section maintenance. It is also concluded that the maximum allowable freeze point of JP-4 or JP-8 cannot be increased without degrading system performance and safety as critical conditions are approached.

  8. Study of LH2 fueled subsonic passenger transport aircraft

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.

    1976-01-01

    The potential of using liquid hydrogen as fuel in subsonic transport aircraft was investigated to explore an expanded matrix of passenger aircraft sizes. Aircraft capable of carrying 130 passengers 2,780 km (1500 n.mi.); 200 passengers 5,560 km (3000 n.mi.); and 400 passengers on a 9,265 km (5000 n.mi.) radius mission, were designed parametrically. Both liquid hydrogen and conventionally fueled versions were generated for each payload/range in order that comparisons could be made. Aircraft in each mission category were compared on the basis of weight, size, cost, energy utilization, and noise.

  9. BREATH MEASUREMENT OF TOTAL BODY BURDEN OF JP-8 JET FUEL FOR EPIDEMIOLOGICAL STUDY

    EPA Science Inventory

    A complex epidemiological investigation of the effects of acute exposure to JP-8 jet fuel in the U.S. Air Force was performed through the study of about 350 human subjects across six Air Force bases. The focus was on fuels system maintenance personnel as the "exposed"...

  10. Study of the feasibility and desirability of using motor fuel dyes and markers. Final report

    SciTech Connect

    1993-08-27

    This study includes a review of experience with the use of dyes and markers, an assessment of the benefits and costs associated with implementing a nationwide standard of motor fuel dyes and markers, and an evaluation of alternative means to achieve similar benefits in consumer fraud prevention and motor fuel tax enforcement.

  11. CYTOGENETIC STUDIES IN MICE TREATED WITH THE JET FUELS, JET-A AND JP-8

    EPA Science Inventory

    Cytogenetic studies in mice treated with the jet fuels, Jet-A and JP-8
    Abstract
    The genotoxic potential of the jet fuels, Jet-A and JP-8, were examined in mice treated on the skin with a single dose of 240 ug/mouse. Peripheral blood smears were prepared at the start of the ...

  12. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE I FINAL REPORT: CONCEPTUAL STUDY

    EPA Science Inventory

    The report discusses results of a conceptual design, cost, and evaluation study of energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The conceptual design of the fuel cell energy recovery system is described, and its economic and environm...

  13. The Gaseous Explosive Reaction : A Study of the Kinetics of Composite Fuels

    NASA Technical Reports Server (NTRS)

    Stevens, F W

    1929-01-01

    This report deals with the results of a series of studies of the kinetics of gaseous explosive reactions where the fuel under observation, instead of being a simple gas, is a known mixture of simple gases. In the practical application of the gaseous explosive reaction as a source of power in the gas engine, the fuels employed are composite, with characteristics that are apt to be due to the characteristics of their components and hence may be somewhat complex. The simplest problem that could be proposed in an investigation either of the thermodynamics or kinetics of the gaseous explosive reaction of a composite fuel would seem to be a separate study of the reaction characteristics of each component of the fuel and then a study of the reaction characteristics of the various known mixtures of those components forming composite fuels more and more complex. (author)

  14. Conceptual study and analysis of hydrogen fueled power plants

    SciTech Connect

    Wang, X; Zhang, S.; Zhao, L.; Cai, R.

    1998-07-01

    To decrease pollution of the environment caused by coal fired plants in China, it is important to develop clean fuel and advanced energy systems. As a kind of efficient, clean, renewable fuel, hydrogen is a prospective alternative to traditional fossil fuel if the problem about hydrogen production and safety can be solved thoroughly. In this paper, several kinds of power generating systems using hydrogen energy have been put forward, analyzed, and discussed. One way of hydrogen utilization is turbine power plant based on stoichiometric reaction of hydrogen and pure oxygen or air, such as the mixing H{sub 2}/O{sub 2} combined cycle. Because the reaction which takes place in the combustor is stoichiometric, the only product is water. So the expansion process of working fluid may include part of the bottoming cycle, which results in a higher efficiency than conventional combined cycle. A new cycle--advanced H{sub 2}/O{sub 2} mixing combined cycle (AMC) is put forward in this paper. The main difference between it and the old one are the adoption of double reheat and semi-closed steam bottoming cycle. Theoretical analysis notes that the efficiency due to the addition of bottoming cycle and reheat is about 6 percentage points higher than the original mixing combined cycle. An alternative closed combined cycle (ACC) developed from the basic closed combined cycle is based on stoichiometric reaction of hydrogen and air. The main characteristic of it is the application of gas recirculation and water reinjection. Compared with the original closed cycle, the emission of this new one is low. Fuel cells which are expected to be used as on site power generating devices in the future provide a new way to hydrogen utilization. A hybrid cycle composed of solid oxide fuel cell, gas turbine, steam turbine and chemical looping combustor (FCC) is put forward in this paper. The key difference between other SOFC systems and this one lies in that in this system, fuel and oxidizer of fuel

  15. A STUDY OF THE DISCREPANCY BETWEEN FEDERAL AND STATE MEASUREMENTS OF ON-HIGHWAY FUEL CONSUMPTION

    SciTech Connect

    Hwang, HL

    2003-08-11

    Annual highway fuel taxes are collected by the Treasury Department and placed in the Highway Trust Fund (HTF). There is, however, no direct connection between the taxes collected by the Treasury Department and the gallons of on-highway fuel use, which can lead to a discrepancy between these totals. This study was conducted to determine how much of a discrepancy exists between the total fuel usages estimated based on highway revenue funds as reported by the Treasury Department and the total fuel usages used in the apportionment of the HTF to the States. The analysis was conducted using data from Highway Statistics Tables MF-27 and FE-9 for the years 1991-2001. It was found that the overall discrepancy is relatively small, mostly within 5% difference. The amount of the discrepancy varies from year to year and varies among the three fuel types (gasoline, gasohol, special fuels). Several potential explanations for these discrepancies were identified, including issues on data, tax measurement, gallon measurement, HTF receipts, and timing. Data anomalies caused by outside forces, such as deferment of tax payments from one fiscal year to the next, can skew fuel tax data. Fuel tax evasion can lead to differences between actual fuel use and fuel taxes collected. Furthermore, differences in data collection and reporting among States can impact fuel use data. Refunds, credits, and transfers from the HTF can impact the total fuel tax receipt data. Timing issues, such as calendar year vs. fiscal year, can also cause some discrepancy between the two data sources.

  16. Preliminary study on direct recycling of spent BWR fuel in BWR system

    NASA Astrophysics Data System (ADS)

    Waris, A.; Sumbono, Prayudhatama, Dythia; Novitrian, Su'ud, Zaki

    2012-06-01

    Spent fuel management is considered to be one of the main problems in energy nuclear utilization. Recycling after reprocessing is one of the options for dealing with nuclear reactor spent fuel. Reprocessing is very costly and needs remote handling since spent fuel is very hazard high level waste. On top of that, only a small number of countries can manage a reprocessing plant. If country likes Indonesia decide to "go nuclear", it should find another way to deal with the nuclear spent fuel. Korea has proposed the DUPIC (Direct Utilization of Spent PWR fuel In CANDU) concept. Nevertheless, DUPIC concept requires two types of nuclear power plants, i.e., pressurized water reactor (PWR) and CANadian Deuterium Uranium reactor (CANDU). In this study, we evaluate a scheme of direct recycling of spent BWR fuel in BWR system, under the concept that we have called as a SUPEL (Straight Utilization of sPEnt LWR fuel in LWR system) scenario. Several spent BWR fuel compositions in loaded BWR fuel has been evaluated to achieve the criticality of reactor.

  17. A study of ethanol low grade as an alternative fuel for small engine

    NASA Astrophysics Data System (ADS)

    Sugiarto, Bambang; Darsono, Dody; Nurhuda, M.; Wardhana, Ing

    2012-06-01

    The availability of non renewable petroleum fuels insists people to make use of alternative energy sources. Currently petroleum dominates the main source of fuel for combustion. Renewable energy is a solution to deal with this issue. One source of renewable energy is bio ethanol. The previous study conducted distillator compact design by utilizing exhaust gases from motor fuels as a primary means of ethanol processing. The goal is to produce viable products into fuel ethanol of which levels above 90%. In this study, it is conducted at the evaporator temperature control with a load of 300 Watt which this conclusions obtained in previous studies on the load 300 Watts has maximum results obtained to be able of consumption needs of fuel on the genset. At 90°C temperature-controlled at the evaporator produces maximum that is able to meet the fuel consumption for the genset. At 85°C temperature-controlled at the evaporator produces high concentric of alcohol but did not meet of fuel consumption. At temperatures of 90°C can be concluded get the most out due to meet the fuel consumption and also has high concentric of alcohol. Gas have low levels of CO (± 1.2% Vol.), low HC (± 150 ppm Vol.).

  18. Fuel Cell Auxiliary Power Study Volume 1: RASER Task Order 5

    NASA Technical Reports Server (NTRS)

    Mak, Audie; Meier, John

    2007-01-01

    This study evaluated the feasibility of a hybrid solid oxide fuel cell (SOFC) auxiliary power unit (APU) and the impact in a 90-passenger More-Electric Regional Jet application. The study established realistic hybrid SOFC APU system weight and system efficiencies, and evaluated the impact on the aircraft total weight, fuel burn, and emissions from the main engine and the APU during cruise, landing and take-off (LTO) cycle, and at the gate. Although the SOFC APU may be heavier than the current conventional APU, its weight disadvantage can be offset by fuel savings in the higher SOFC APU system efficiencies against the main engine bleed and extraction during cruise. The higher SOFC APU system efficiency compared to the conventional APU on the ground can also provide considerable fuel saving and emissions reduction, particularly at the gate, but is limited by the fuel cell stack thermal fatigue characteristic.

  19. Fuel flexibility study of an integrated 25 kW SOFC reformer system

    NASA Astrophysics Data System (ADS)

    Yi, Yaofan; Rao, Ashok D.; Brouwer, Jacob; Samuelsen, G. Scott

    The operation of solid oxide fuel cells on various fuels, such as natural gas, biogas and gases derived from biomass or coal gasification and distillate fuel reforming has been an active area of SOFC research in recent years. In this study, we develop a theoretical understanding and thermodynamic simulation capability for investigation of an integrated SOFC reformer system operating on various fuels. The theoretical understanding and simulation results suggest that significant thermal management challenges may result from the use of different types of fuels in the same integrated fuel cell reformer system. Syngas derived from coal is simulated according to specifications from high-temperature entrained bed coal gasifiers. Diesel syngas is approximated from data obtained in a previous NFCRC study of JP-8 and diesel operation of the integrated 25 kW SOFC reformer system. The syngas streams consist of mixtures of hydrogen, carbon monoxide, carbon dioxide, methane and nitrogen. Although the SOFC can tolerate a wide variety in fuel composition, the current analyses suggest that performance of integrated SOFC reformer systems may require significant operating condition changes and/or system design changes in order to operate well on this variety of fuels.

  20. Studies of new perfluoroether elastomeric sealants. [for aircraft fuel tanks

    NASA Technical Reports Server (NTRS)

    Basiulis, D. I.; Salisbury, D. P.

    1981-01-01

    Channel and filleting sealants were developed successfully from cyano and diamidoxime terminated perfluoro alkylene ether prepolymers. The prepolymers were polymerized, formulated and tested. The polymers and/or formulations therefrom were evaluated as to their physical, mechanical and chemical properties (i.e., specific gravity, hardness, nonvolatile content, corrosion resistance, stress corrosion, pressure rupture resistance, low temperature flexibility, gap sealing efficiency, tensile strength and elongation, dynamic mechanical behavior, compression set, fuel resistance, thermal properties and processability). Other applications of the formulated polymrs and incorporation of the basic prepolymers into other polymeric systems were investigated. A cyano terminated perfluoro alkylene oxide triazine was formulated and partially evaluated. The channel sealant in its present formulation has excellent pressure rupture resistance and surpasses present MIL specifications before and after fuel and heat aging.

  1. Flame ignition studies of conventional and alternative jet fuels and surrogate components

    NASA Astrophysics Data System (ADS)

    Liu, Ning

    concentrations. As for the detailed high temperature oxidation chemistry, ignition of normal, branched, and cyclic alkane flames were found to be sensitive largely to H2/CO and C1-C4 small hydrocarbon chemistry, while for branched alkanes fuel-related reactions do have accountable effect on ignition due to the low rate of initial fuel decomposition that limits the overall reactions preceding ignition. Analyses of the computed flame structures revealed that the concentrations of ignition-promoting radicals such as H, HCO, C2H3, and OH, and ignition-inhibiting radicals such as C3H6, aC3H5, and CH3 are key to the occurrence of ignition. Finally, the ignition characteristics of conventional and alternative jet fuels were studied and were to correlate with the chemical classifications and diffusivities of the neat species that are present in the practical fuel.

  2. Study of new proton conducting glasses for fuel cells

    NASA Astrophysics Data System (ADS)

    Tiple, S. R.; Deshpande, V. K.

    2015-08-01

    The glasses in the series (35-x) BaO:65 P2O5:x (NH4)2SO4 are synthesized and characterized by Tg, CTE, density and electrical conductivity measurements. The decrease in density and Tg is observed with addition of (NH4)2SO4. The increase in CTE compliments the observed variation in Tg. The protonic conductivity increases with addition of (NH4)2SO4 up to 7.5 mol% and decreases beyond this composition. The increase in the ratio of O/P, which in turn, creates more non-bridging oxygens, enhances the conductivity. Further, sulfur is mainly incorporated in sulfophosphate glasses as isolated SO42- group which also results in increase in conductivity. The glass with maximum conductivity [7.5(NH4)2SO4:27.5BaO:65 P2O5] is used to fabricate a fuel cell. It gives the power density of 12.43 μW/cm2. The power density of the fuel cell in the present work at room temperature is higher than that reported in literature at 473 K. The fuel cell has a potential of giving higher power density at higher temperature of 423 K.

  3. Studies of Flexible MOX/LEU Fuel Cycles

    SciTech Connect

    Adams, M.L.; Alonso-Vargas, G.

    1999-03-01

    This project was a collaborative effort involving researchers from Oak Ridge National Laboratory and North Carolina State University as well as Texas A and M University. The background, briefly, is that the US is planning to use some of its excess weapons Plutonium (Pu) to make mixed-oxide (MOX) fuel for existing light-water reactors (LWRs). Considerable effort has already gone into designing fuel assemblies and core loading patterns for the transition from full-uranium cores to partial-MOX and full-MOX cores. However, these designs have assumed that any time a reactor needs MOX assemblies, these assemblies will be supplied. In reality there are many possible scenarios under which this supply could be disrupted. It therefore seems prudent to verify that a reactor-based Pu-disposition program could tolerate such interruptions in an acceptable manner. Such verification was the overall aim of this project. The task assigned to the Texas A and M team was to use the HELIOS code to develop libraries of two-group homogenized cross sections for the various assembly designs that might be used in a Westinghouse Pressurized Water Reactor (PWR) that is burning weapons-grade MOX fuel. The NCSU team used these cross sections to develop optimized loading patterns under several assumed scenarios. Their results are documented in a companion report.

  4. Quantitative degradation studies of coal derived jet fuel using statistical analysis

    SciTech Connect

    Sanghani, P.C.; Boehman, A.L.

    1996-10-01

    The kinetics of coke formation from coal-derived jet fuel were studied using statistical methods. The degree of correlation between deposit (coke) growth and species concentration has been examined. Formation of deposits from the mixtures of jet fuel and tetradecane was proportional to the initial concentration of tetradecane present in the fuel. Decomposition of tetradecane was found to be first order with con-elation coefficient of 0.98. Other normal alkanes species such as dodecane, tridecane, and pentadecane which are present in very small amount also contribute significantly to deposit growth. Cycloalkanes, alkylated c1,c2,c3 benzenes, alkylated naphathalenes present in coal derived jet fuel were very stable compared to tetradecane. The statistical approach helps in identifying or arranging species in terms of their contribution to deposit formation. Grouping species on the basis of their correlation with deposit formation clarifies the required structure for a general kinetic model of the jet fuel degradation process.

  5. Studies of jet fuel additives using the quartz crystal microbalance and pressure monitoring at 140 C

    SciTech Connect

    Zabarnick, S.; Grinstead, R.R. . Aerospace Mechanics Div./KL-463)

    1994-11-01

    Recent advances in jet aircraft and engine technology have placed an ever increasing heat load on the aircraft. The bulk of this excess heat is absorbed by the aircraft fuel, as jet fuel is used as the primary coolant for the numerous heat sources. The quartz crystal microbalance (QCM) and pressure monitoring are used for the evaluation of jet fuel additives for the improvement of jet fuel thermal stability. The mechanisms of additive behavior are determined by measuring the time-dependent deposition with the QCM and oxidation by pressure measurements. Studies at various additive concentrations permits the determination of optimum additive concentrations. Additive packages made of mixtures of antioxidants, detergent/dispersants, and metal deactivators are shown to yield good improvements in thermal stability over a wide range of jet fuel types.

  6. An experimental study of fuel injection strategies in CAI gasoline engine

    SciTech Connect

    Hunicz, J.; Kordos, P.

    2011-01-15

    Combustion of gasoline in a direct injection controlled auto-ignition (CAI) single-cylinder research engine was studied. CAI operation was achieved with the use of the negative valve overlap (NVO) technique and internal exhaust gas re-circulation (EGR). Experiments were performed at single injection and split injection, where some amount of fuel was injected close to top dead centre (TDC) during NVO interval, and the second injection was applied with variable timing. Additionally, combustion at variable fuel-rail pressure was examined. Investigation showed that at fuel injection into recompressed exhaust fuel reforming took place. This process was identified via an analysis of the exhaust-fuel mixture composition after NVO interval. It was found that at single fuel injection in NVO phase, its advance determined the heat release rate and auto-ignition timing, and had a strong influence on NO{sub X} emission. However, a delay of single injection to intake stroke resulted in deterioration of cycle-to-cycle variability. Application of split injection showed benefits of this strategy versus single injection. Examinations of different fuel mass split ratios and variable second injection timing resulted in further optimisation of mixture formation. At equal share of the fuel mass injected in the first injection during NVO and in the second injection at the beginning of compression, the lowest emission level and cyclic variability improvement were observed. (author)

  7. Numerical and experimental studies of the hybrid rocket motor with multi-port fuel grain

    NASA Astrophysics Data System (ADS)

    Tian, Hui; Li, Xintian; Zeng, Peng; Yu, Nanjia; Cai, Guobiao

    2014-03-01

    This paper presents three-dimensional numerical simulations and experimental studies of the hybrid rocket motor with multi-port fuel grain. The numerical model is established based on the Navier-Stokes equations with turbulence, chemical reactions, fuel pyrolysis, and solid-gas boundary interactions. The simulation is performed based on the 98% hydrogen peroxide (HP) and hydroxyl terminated polybutadiene (HTPB) propellant combination. The results indicate that the flow field and fuel regression rate distributions present apparent three-dimensional characteristics. The fuel regression rates decrease first and then gradually increase with the axial location increasing. At a certain cross section, the fuel regression rates are lower in the points on arcs with smaller radius of curvature when the fuel port is a derivable convex figure. Two experiments are carried out on a full scale motor with the simulation one. The working process of the motor is steady and no evident oscillatory combustion is observed. The fuel port profiles before and after tests indicate that the fuel regression rate distributions at the cross section match well with the numerical simulation results.

  8. Fuel instability studies; Liquid phase oxidation of tetrahydrothiophene by tert-butyl hydroperoxide

    SciTech Connect

    Mushrush, G.W.; Pellenbarg, R.E.; Hazlett, R.N.; Morris, R.E.; Hardy, D.R. )

    1991-01-01

    The reactions that lead to fuel instability are the subject of conflicting reports in the literature. Confusion results from the difficulty in relating differences in fuel composition, temperature, surface effects and dissolved oxygen content that comprise the multitude of reported studies. Model studies offer a means by chic the mechanism of an individual reaction can be related to a simple system and then extended to the more complex fuel media. This paper reports a model oxidation study of a species, t-butyl hydroperoxide under mild reaction conditions, 120{degrees}C, in a tetradecane model fuel. The major oxidation product was tetrahydrothiophene sulfoxide from the sulfide and t-butanol from the hydroperoxide. The complete suite of products is reported.

  9. Study of effects of injector geometry on fuel-air mixing and combustion

    NASA Technical Reports Server (NTRS)

    Bangert, L. H.; Roach, R. L.

    1977-01-01

    An implicit finite-difference method has been developed for computing the flow in the near field of a fuel injector as part of a broader study of the effects of fuel injector geometry on fuel-air mixing and combustion. Detailed numerical results have been obtained for cases of laminar and turbulent flow without base injection, corresponding to the supersonic base flow problem. These numerical results indicated that the method is stable and convergent, and that significant savings in computer time can be achieved, compared with explicit methods.

  10. Study of the application of hydrogen fuel to long-range subsonic transport aircraft, volume 2

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

    1975-01-01

    The feasibility, practicability, and potential advantages/disadvantages of using liquid hydrogen as fuel in long range, subsonic transport aircraft of advanced design were studied. Both passenger and cargo-type aircraft were investigated. To provide a valid basis for comparison, conventional hydrocarbon (Jet A) fueled aircraft were designed to perform identical missions using the same advanced technology and meeting the same operational constraints. The liquid hydrogen and Jet A fueled aircraft were compared on the basis of weight, size, energy utilization, cost, noise, emissions, safety, and operational characteristics. A program of technology development was formulated.

  11. Fuel-Neutral Studies of PM Transportation Emissions

    SciTech Connect

    Stewart, Mark L.; Zelenyuk, Alla; Howden, Ken

    2012-11-15

    New gasoline engine technologies such as Spark Ignition Direct Injection (SIDI), Gasoline Direct Injection Compression Ignition (GDICI), and Reaction Controlled Compression Ignition (RCCI) offer the possibility of dramatically increasing the fuel efficiency of future vehicles. One drawback to these advanced engines is that they have the potential to produce higher levels of exhaust particulates than current Port Fuel Injection (PFI) engines. Regulation of engine particulate emissions in Europe is moving from mass-based standards toward number-based standards. Due to growing health concerns surrounding nano-aerosols, it is likely that similar standards will eventually be applied in the United States. This would place more emphasis on the reliable removal of smaller particles, which make up the vast majority of the particulates generated on a number basis. While Diesel Particulate Filters (DPF) have become standard, different filter systems would likely be required for advanced gasoline vehicles, due to factors such as differing particulate properties and higher exhaust temperatures. High exhaust temperatures can limit the accumulation of a soot cake, which performs most of the actual filtration in a typical DPF system.

  12. High Burn-Up Spent Nuclear Fuel Vibration Integrity Study

    SciTech Connect

    Wang, Jy-An John; Wang, Hong; Jiang, Hao; Bevard, Bruce Balkcom; Howard, Rob L; Scaglione, John M

    2015-01-01

    The Oak Ridge National Laboratory (ORNL) has developed the cyclic integrated reversible-bending fatigue tester (CIRFT) approach to successfully demonstrate the controllable fatigue fracture on high burnup (HBU) spent nuclear fuel (SNF) in a normal vibration mode. CIRFT enables examination of the underlying mechanisms of SNF system dynamic performance. Due to the inhomogeneous composite structure of the SNF system, the detailed mechanisms of the pellet-pellet and pellet-clad interactions and the stress concentration effects at the pellet-pellet interface cannot be readily obtained from a CIRFT system measurement. Therefore, finite element analyses (FEAs) are used to translate the global moment-curvature measurement into local stress-strain profiles for further investigation. The major findings of CIRFT on the HBU SNF are as follows: SNF system interface bonding plays an important role in SNF vibration performance. Fuel structure contributes to SNF system stiffness. There are significant variations in stress and curvature of SNF systems during vibration cycles resulting from segment pellets and clad interactions. SNF failure initiates at the pellet-pellet interface region and appears to be spontaneous.

  13. Microbial studies in the Canadian nuclear fuel waste management program.

    PubMed

    Stroes-Gascoyne, S; West, J M

    1997-07-01

    Atomic Energy of Canada Limited (AECL) has developed a concept for permanent geological disposal of used nuclear fuel in Canada. This concept, based on a multibarrier system, would involve disposal of nuclear fuel waste in titanium or copper containers, surrounded by compacted clay-based buffer and backfill materials, in a vault 500-1000 m deep in granitic rock of the Canadian Shield. Subsurface environments will not be sterile and an experimental program was initiated in 1991 by AECL to address and quantify the potential effects of microbial action on the integrity of the disposal vault. This microbial program focuses on answering specific questions in areas such as the survival of bacteria in compacted clay-based buffer materials under relevant radiation, temperature and desiccation conditions; mobility of microbes in compacted buffer materials; the potential for microbially influenced corrosion of containers; microbial gas production in backfill material; introduction of nutrients as a result of vault excavation and operation; the presence and activity of microbes in deep granitic groundwaters; and the effects of biofilms on radionuclide migration in the geosphere. This paper summarizes the results to date from the research activities at AECL. PMID:9299719

  14. Microbial studies in the Canadian nuclear fuel waste management program.

    PubMed

    Stroes-Gascoyne, S; West, J M

    1997-07-01

    Atomic Energy of Canada Limited (AECL) has developed a concept for permanent geological disposal of used nuclear fuel in Canada. This concept, based on a multibarrier system, would involve disposal of nuclear fuel waste in titanium or copper containers, surrounded by compacted clay-based buffer and backfill materials, in a vault 500-1000 m deep in granitic rock of the Canadian Shield. Subsurface environments will not be sterile and an experimental program was initiated in 1991 by AECL to address and quantify the potential effects of microbial action on the integrity of the disposal vault. This microbial program focuses on answering specific questions in areas such as the survival of bacteria in compacted clay-based buffer materials under relevant radiation, temperature and desiccation conditions; mobility of microbes in compacted buffer materials; the potential for microbially influenced corrosion of containers; microbial gas production in backfill material; introduction of nutrients as a result of vault excavation and operation; the presence and activity of microbes in deep granitic groundwaters; and the effects of biofilms on radionuclide migration in the geosphere. This paper summarizes the results to date from the research activities at AECL.

  15. NEUTRONICS STUDIES OF URANIUM-BASED FULLY CERAMIC MICRO-ENCAPSULATED FUEL FOR PWRs

    SciTech Connect

    George, Nathan M; Maldonado, G Ivan; Terrani, Kurt A; Gehin, Jess C; Godfrey, Andrew T

    2012-01-01

    This study evaluates the core neutronics and fuel cycle characteristics that result from employing uranium-based fully ceramic micro-encapsulated (FCM) fuel in a pressurized water reactor (PWR). Specific PWR bundle designs with FCM fuel have been developed, which by virtue of their TRISO particle based elements, are expected to safely reach higher fuel burnups while also increasing the tolerance to fuel failures. The SCALE 6.1 code package, developed and maintained at ORNL, was the primary software employed to model these designs. Analysis was performed using the SCALE double-heterogeneous (DH) fuel modeling capabilities. For cases evaluated with the NESTLE full-core three-dimensional nodal simulator, because the feature to perform DH lattice physics branches with the SCALE/TRITON sequence is not yet available, the Reactivity-Equivalent Physical Transformation (RPT) method was used as workaround to support the full core analyses. As part of the fuel assembly design evaluations, fresh feed lattices were modeled to analyze the within-assembly pin power peaking. Also, a color-set array of assemblies was constructed to evaluate power peaking and power sharing between a once-burned and a fresh feed assembly. In addition, a parametric study was performed by varying the various TRISO particle design features; such as kernel diameter, coating layer thicknesses, and packing fractions. Also, other features such as the selection of matrix material (SiC, Zirconium) and fuel rod dimensions were perturbed. After evaluating different uranium-based fuels, the higher physical density of uranium mononitride (UN) proved to be favorable, as the parametric studies showed that the FCM particle fuel design will need roughly 12% additional fissile material in comparison to that of a standard UO2 rod in order to match the lifetime of an 18-month PWR cycle. Neutronically, the FCM fuel designs evaluated maintain acceptable design features in the areas of fuel lifetime, temperature

  16. Discrete element method study of fuel relocation and dispersal during loss-of-coolant accidents

    NASA Astrophysics Data System (ADS)

    Govers, K.; Verwerft, M.

    2016-09-01

    The fuel fragmentation, relocation and dispersal (FFRD) during LOCA transients today retain the attention of the nuclear safety community. The fine fragmentation observed at high burnup may, indeed, affect the Emergency Core Cooling System performance: accumulation of fuel debris in the cladding ballooned zone leads to a redistribution of the temperature profile, while dispersal of debris might lead to coolant blockage or to debris circulation through the primary circuit. This work presents a contribution, by discrete element method, towards a mechanistic description of the various stages of FFRD. The fuel fragments are described as a set of interacting particles, behaving as a granular medium. The model shows qualitative and quantitative agreement with experimental observations, such as the packing efficiency in the balloon, which is shown to stabilize at about 55%. The model is then applied to study fuel dispersal, for which experimental parametric studies are both difficult and expensive.

  17. The study of integrated coal-gasifier molten carbonate fuel cell systems

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A novel integration concept for a coal-fueled coal gasifier-molten carbonate fuel cell power plant was studied. Effort focused on determining the efficiency potential of the concept, design, and development requirements of the processes in order to achieve the efficiency. The concept incorporates a methane producing catalytic gasifier of the type previously under development by Exxon Research and Development Corp., a reforming molten carbonate fuel cell power section of the type currently under development by United Technologies Corp., and a gasifier-fuel cell recycle loop. The concept utilizes the fuel cell waste heat, in the form of hydrogen and carbon monoxide, to generate additional fuel in the coal gasifier, thereby eliminating the use of both an O2 plant and a stream bottoming cycle from the power plant. The concept has the potential for achieving coal-pile-to-busbar efficiencies of 50-59%, depending on the process configuration and degree of process configuration and degree of process development requirements. This is significantly higher than any previously reported gasifier-molten carbonate fuel cell system.

  18. Experimental study of the microbial fuel cell internal resistance

    NASA Astrophysics Data System (ADS)

    Zhang, Pei-Yuan; Liu, Zhong-Liang

    The internal resistance, including activation loss internal resistance (AIR), ohmic loss internal resistance (OIR) and concentration loss internal resistance (CIR), is an important parameter that determines the performance of microbial fuel cells (MFCs). The experimental investigations were completed to estimate the contributions of these three components to the internal resistance. The internal resistance is found to vary with electric current, although it is almost a constant for the current is within a certain region. The largest component of the internal resistance is CIR except for small currents. The AIR decreases quickly for small current and reduces its decreasing rate as the current increases and approaches to a constant. The OIR is constant over the whole current range. The experiments also disclose that increasing the limiting current and reducing the concentration loss are both important for improving the MFC performance.

  19. Engineering study: 105KE to 105KW Basin fuel and sludge transfer. Final report

    SciTech Connect

    Gant, R.G.

    1994-09-20

    In the last five years, there have been three periods at the 105KE fuel storage basin (KE Basin) where the reported drawdown test rates were in excess of 25 gph. Drawdown rates in excess of this amount have been used during past operations as the primary indicators of leaks in the basin. The latest leak occurred in March, 1993. The reported water loss from the KE Basin was estimated at 25 gph. This engineering study was performed to identify and recommend the most feasible and practical method of transferring canisters of irradiated fuel and basin sludge from the KE Basin to the 105KW fuel storage basin (KW Basin). Six alternatives were identified during the performance of this study as possible methods for transferring the fuel and sludge from the KE Basin to the KW Basin. These methods were then assessed with regard to operations, safety, radiation exposure, packaging, environmental concerns, waste management, cost, and schedule; and the most feasible and practical methods of transfer were identified. The methods examined in detail in this study were based on shipment without cooling water except where noted: Transfer by rail using the previously used transfer system and water cooling; Transfer by rail using the previously used transfer system (without water cooling); Transfer by truck using the K Area fuel transfer cask (K Area cask); Transfer by truck using a DOE shipping cask; Transfer by truck using a commercial shipping cask; and Transfer by truck using a new fuel shipping cask.

  20. Reactor Physics Scoping and Characterization Study on Implementation of TRIGA Fuel in the Advanced Test Reactor

    SciTech Connect

    Jennifer Lyons; Wade R. Marcum; Mark D. DeHart; Sean R. Morrell

    2014-01-01

    The Advanced Test Reactor (ATR), under the Reduced Enrichment for Research and Test Reactors (RERTR) Program and the Global Threat Reduction Initiative (GTRI), is conducting feasibility studies for the conversion of its fuel from a highly enriched uranium (HEU) composition to a low enriched uranium (LEU) composition. These studies have considered a wide variety of LEU plate-type fuels to replace the current HEU fuel. Continuing to investigate potential alternatives to the present HEU fuel form, this study presents a preliminary analysis of TRIGA® fuel within the current ATR fuel envelopes and compares it to the functional requirements delineated by the Naval Reactors Program, which includes: greater than 4.8E+14 fissions/s/g of 235U, a fast to thermal neutron flux ratio that is less than 5% deviation of its current value, a constant cycle power within the corner lobes, and an operational cycle length of 56 days at 120 MW. Other parameters outside those put forth by the Naval Reactors Program which are investigated herein include axial and radial power profiles, effective delayed neutron fraction, and mean neutron generation time.

  1. Results from studies of surface deposits on the claddings of fuel rods used in RBMK-1000 reactors

    NASA Astrophysics Data System (ADS)

    Smirnova, I. M.; Markov, D. V.

    2010-07-01

    The results of studies on analyzing the element composition of deposits on the cladding surfaces of fuel rods used in a fuel assembly at the Leningrad nuclear power station are presented. The distribution of elements in deposits over the fuel rod height is analyzed, and the zones of their concentration are revealed. It is shown that deposits of copper penetrating into cracks in the surface layer of zirconium oxide introduce an essential contribution in the development of nodular corrosion of fuel rod claddings.

  2. Parametric study of factors affecting the fuel efficiency of advanced turboprop airplanes

    NASA Technical Reports Server (NTRS)

    Johnson, V. S.

    1983-01-01

    Results of a parametric study to determine the effects of design variables and penalties on the fuel efficiency of Mach 0.8, 125-passenger, advanced turboprop airplanes show that propeller-wing interference penalty has a major effect. Propeller tip speed has a minor effect, and could be decreased to alleviate the noise problem without significant effects on fuel efficiency. The anticipated noise levels produced by the propfan will require additional acoustical treatment for the fuselage; this additional weight can have a significant effect on fuel efficiency. The propfan advantage over an equivalent technology turbofan is strongly dependent on the interference penalty and acoustical treatment weight. Lowering the cruise Mach number to around 0.73 would result in greatly increased fuel efficiency.

  3. Feasibility study: fuel cell cogeneration at the Anheuser-Busch Los Angeles brewery

    SciTech Connect

    Banister, R.M.; Corea, V.A.; Sorensen, J.C.; Duncan, J.M.; Rudawitz, L.; Verdes, R.

    1980-02-01

    The results of a feasibility study undertaken in support of the overall Department of Energy (DOE) goal to develop fuel cell power plants for industrial cogeneration are described. Use of a single 4.5 MW fuel cell power plant like that manufactured by United Technologies Corporation (UTC) and currently being constructed on the Consolidated Edison of New York System was examined. The technical feasibility of using such a plant in a cogeneration mode at the Anheuser-Busch, Los Angeles brewery was affirmed by the study. Break-even capital costs for UTC supplied equipment were calculated for various conditions. Based upon the assumption that UTC supplied equipment could be provided for the $350 to $400/kW projected for first generation fuel cells, the economic feasibility of fuel cell cogeneration was demonstrated for nearly all assumed conditions. The most economical case was found to be a municipal utility owned, base loaded power plant where economic credit is taken for reduced environmental emissions. Acceptable fuels were evaluated for their availability, and the fuels identified for use were natural gas with propane as a backup. Phosphoric acid is the selected electrolyte. The Demonstration Program Plan is described. (WHK)

  4. Feasibility study: fuel cell cogeneration in a water pollution control facility. Final report

    SciTech Connect

    Not Available

    1980-02-01

    A conceptual design study was conducted to investigate the technical and economic feasibility of a cogeneration fuel cell power plant operating in a large water pollution control facility. The fuel cell power plant would use methane-rich digester gas from the water pollution control facility as a fuel feedstock to provide electrical and thermal energy. Several design configurations were evaluated. These configurations were comprised of combinations of options for locating the fuel cell power plant at the site, electrically connecting it with the water pollution control facility, using the rejected power plant heat, supplying fuel to the power plant, and for ownership and operation. A configuration was selected which met institutional/regulatory constraints and provided a net cost savings to the industry and the electric utility. This volume of the report contains the appendices: (A) abbreviations and definitions, glossary; (B) 4.5 MWe utility demonstrator power plant study information; (C) rejected heat utilization; (D) availability; (E) conceptual design specifications; (F) details of the economic analysis; (G) detailed description of the selected configuration; and (H) fuel cell power plant penetration analysis. (WHK)

  5. Feasibility study for a DOE research and production fuel multipurpose canister

    SciTech Connect

    Lopez, D.A.; Abbott, D.G.

    1994-02-01

    This is a report of the feasibility of multipurpose canisters for transporting, storing, and sing of Department of Energy research and production spent nuclear fuel. Six representative Department of Energy fuel assemblies were selected, and preconceptual canister designs were developed to accommodate these assemblies. The study considered physical interface, structural adequacy, criticality safety, shielding capability, thermal performance of the canisters, and fuel storage site infrastructure. The external envelope of the canisters was designed to fit within the overpack casks for commercial canisters being developed for the Department of Energy Office of Civilian Radioactive Waste Management. The budgetary cost of canisters to handle all fuel considered is estimated at $170.8M. One large conceptual boiling water reactor canister design, developed for the Office of Civilian Radioactive Waste Management, and two new canister designs can accommodate at least 85% of the volume of the Department of Energy fuel considered. Canister use minimizes public radiation exposure and is cost effective compared with bare fuel handling. Results suggest the need for additional study of issues affecting canister use and for conceptual design development of the three canisters.

  6. Masters Study in Advanced Energy and Fuels Management

    SciTech Connect

    Mondal, Kanchan

    2014-12-08

    There are currently three key drivers for the US energy sector a) increasing energy demand and b) environmental stewardship in energy production for sustainability and c) general public and governmental desire for domestic resources. These drivers are also true for energy nation globally. As a result, this sector is rapidly diversifying to alternate sources that would supplement or replace fossil fuels. These changes have created a need for a highly trained workforce with a the understanding of both conventional and emerging energy resources and technology to lead and facilitate the reinvention of the US energy production, rational deployment of alternate energy technologies based on scientific and business criteria while invigorating the overall economy. In addition, the current trends focus on the the need of Science, Technology, Engineering and Math (STEM) graduate education to move beyond academia and be more responsive to the workforce needs of businesses and the industry. The SIUC PSM in Advanced Energy and Fuels Management (AEFM) program was developed in response to the industries stated need for employees who combine technical competencies and workforce skills similar to all PSM degree programs. The SIUC AEFM program was designed to provide the STEM graduates with advanced technical training in energy resources and technology while simultaneously equipping them with the business management skills required by professional employers in the energy sector. Technical training include core skills in energy resources, technology and management for both conventional and emerging energy technologies. Business skills training include financial, personnel and project management. A capstone internship is also built into the program to train students such that they are acclimatized to the real world scenarios in research laboratories, in energy companies and in government agencies. The current curriculum in the SIUC AEFM will help fill the need for training both recent

  7. Ionic conductivity studies of solid oxide fuel cell electrolytes and theoretical modeling of an entire solid oxide fuel cell

    NASA Astrophysics Data System (ADS)

    Pornprasertsuk, Rojana

    Because of the steep increase in oil prices, the global warming effect and the drive for energy independence, alternative energy research has been encouraged worldwide. The sustainable fuels such as hydrogen, biofuel, natural gas, and solar energy have attracted the attention of researchers. To convert these fuels into a useful energy source, an energy conversion device is required. Fuel cells are one of the energy conversion devices which convert chemical potentials into electricity. Due to their high efficiency, the ease to scale from 1 W range to megawatts range, no recharging requirement and the lack of CO2 and NOx emission (if H2 and air/O 2 are used), fuel cells have become a potential candidate for both stationary power generators and portable applications. This thesis has been focused primarily on solid oxide fuel cell (SOFC) studies due to its high efficiency, varieties of fuel choices, and no water management problem. At the present, however, practical applications of SOFCs are limited by high operating temperatures that are needed to create the necessary oxide-ion vacancy mobility in the electrolyte and to create sufficient electrode reactivities. This thesis introduces several experimental and theoretical approaches to lower losses both in the electrolyte and the electrodes. Yttria stabilized zirconia (YSZ) is commonly used as a solid electrolyte for SOFCs due to its high oxygen-ion conductivity. To improve the ionic conductivity for low temperature applications, an approach that involves dilating the structure by irradiation and introducing edge dislocations into the electrolyte was studied. Secondly, to understand the activation loss in SOFC, the kinetic Monte Carlo (KMC) technique was implemented to model the SOFC operation to determining the rate-limiting step due to the electrodes on different sizes of Pt catalysts. The isotope exchange depth profiling technique was employed to investigate the irradiation effect on the ionic transport in different

  8. Study of the application of hydrogen fuel to long-range subsonic transport aircraft. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.; Lange, R. H.; Moore, J. W.

    1975-01-01

    The feasibility of using liquid hydrogen as fuel in advanced designs of long range, subsonic transport aircraft is assessed. Both passenger and cargo type aircraft are investigated. Comparisons of physical, performance, and economic parameters of the LH2 fueled designs with conventionally fueled aircraft are presented. Design studies are conducted to determine appropriate characteristics for the hydrogen related systems required on board the aircraft. These studies included consideration of material, structural, and thermodynamic requirements of the cryogenic fuel tanks and fuel systems with the structural support and thermal protection systems.

  9. Theoretical studies of transient criticality of irradiated fuel elements

    SciTech Connect

    Barbry, F.; Bonhomme, C.; Hague, P.; Mather, D.J.; Shaw, P.M.

    1987-01-01

    The use of transport flasks containing irradiated fuel is a common event, and their movements are strictly regulated by the national competent authority in order that an acceptable level of control of radiation hazards be maintained. Nonetheless it has been considered prudent to quantify the consequences of a particular hypothetical accident involving a transport package. The particular accident examined assumed that recriticality occurs during the refilling of a flask, and for the Commissariat a l'Energie Atomique (CEA) scenario, for which flasks are transported dry, the hypothetical accident occurs as the flask is slowly lowered into a storage pond. An alternative UK scenario assumes that the flask is being refilled, following breach, by a high-pressure hose. Thus, the consequences of such an accident were estimated by developing computer codes, Chateau by the CEA and Sartemp by the UK Atomic Energy Authority (UKAEA). This and other results show that the hypothetical accident in which a transport flask is brought to critical by the reentry of water gives at most a relatively mild event. In view of the considerably unlikely circumstances and conservative aspects introduced, this result shows that such an accident can be safely contained.

  10. US--EC fuel cycle study: Background document to the approach and issues

    SciTech Connect

    Cantor, Robin; Lee, Russell

    1992-11-01

    In February 1991, DOE and the Commission of the European Communities (EC), signed a joint statement regarding the external costs of fuel cycles. This 18-month agreement committed their respective organizations to ``develop a comparative analytical methodology and to develop the best range of estimates of external costs from secondary sources`` for eight fuel cycles and four conservation options. In our study, a fuel cycle is defined as the series of physical and chemical processes and activities that are required to generate electricity from a specific fuel or resource. This foundation phase of the study is primarily limited to developing and demonstrating methods for estimating impacts and their monetized value, what we term ``damages`` or ``benefits,`` leaving aside the extent to which such damages have been internalized. However, Appendix C provides the conceptual framework for evaluating the extent of internalization. This report is a background document to introduce the study approach and to discuss the major conceptual and practical issues entailed by the incremental damage problem. As a background document, the report seeks to communicate an overview of the study and the important methodological choices that were made to conduct the research. In successive sections of the report, the methodological tools used in the study are discussed; the ecological and health impacts are reviewed using the coal fuel cycle as a reference case; and, in the final chapter, the methods for valuing impacts are detailed.

  11. U.S. -- EC fuel cycle study: Background document to the approach and issues

    SciTech Connect

    Cantor, Robin; Russell, Lee; Krupnick, Alan; Smith, Hilary; Schaffhauser, Jr., A.; Barnthouse, Larry; Cada, Glen; Kroodsma, Roger; Turner, Robb; Easterly, Clay; Jones, Troyce; Burtraw, Dallas; Harrington, Winston; Freeman, A. Myrick

    1992-11-01

    In February 1991, DOE and the Commission of the European Communities (EC), signed a joint statement regarding the external costs of fuel cycles. This 18-month agreement committed their respective organizations to develop a comparative analytical methodology and to develop the best range of estimates of external costs from secondary sources'' for eight fuel cycles and four conservation options. In our study, a fuel cycle is defined as the series of physical and chemical processes and activities that are required to generate electricity from a specific fuel or resource. This foundation phase of the study is primarily limited to developing and demonstrating methods for estimating impacts and their monetized value, what we term damages'' or benefits,'' leaving aside the extent to which such damages have been internalized. However, Appendix C provides the conceptual framework for evaluating the extent of internalization. This report is a background document to introduce the study approach and to discuss the major conceptual and practical issues entailed by the incremental damage problem. As a background document, the report seeks to communicate an overview of the study and the important methodological choices that were made to conduct the research. In successive sections of the report, the methodological tools used in the study are discussed; the ecological and health impacts are reviewed using the coal fuel cycle as a reference case; and, in the final chapter, the methods for valuing impacts are detailed.

  12. Disposal options for burner ash from spent graphite fuel. Final study report November 1993

    SciTech Connect

    Pinto, A.P.

    1994-08-01

    Three major disposal alternatives are being considered for Fort St. Vrain Reactor (FSVR) and Peach Bottom Reactor (PBR) spent fuels: direct disposal of packaged, intact spent fuel elements; (2) removal of compacts to separate fuel into high-level waste (HLW) and low-level waste (LLW); and (3) physical/chemical processing to reduce waste volumes and produce stable waste forms. For the third alternative, combustion of fuel matrix graphite and fuel particle carbon coatings is a preferred technique for head-end processing as well as for volume reduction and chemical pretreatment prior to final fixation, packaging, and disposal of radioactive residuals (fissile and fertile materials together with fission and activation products) in a final repository. This report presents the results of a scoping study of alternate means for processing and/or disposal of fissile-bearing particles and ash remaining after combustion of FSVR and PBR spent graphite fuels. Candidate spent fuel ash (SFA) waste forms in decreasing order of estimated technical feasibility include glass-ceramics (GCs), polycrystalline ceramic assemblages (PCAs), and homogeneous amorphous glass. Candidate SFA waste form production processes in increasing order of estimated effort and cost for implementation are: low-density GCs via fuel grinding and simultaneous combustion and waste form production in a slagging cyclone combustor (SCC); glass or low-density GCs via fluidized bed SFA production followed by conventional melting of SFA and frit; PCAs via fluidized bed SFA production followed by hot isostatic pressing (HIPing) of SFA/frit mixtures; and high-density GCs via fluidized bed SFA production followed by HIPing of Calcine/Frit/SFA mixtures.

  13. Performance study of sugar-yeast-ethanol bio-hybrid fuel cells

    NASA Astrophysics Data System (ADS)

    Jahnke, Justin P.; Mackie, David M.; Benyamin, Marcus; Ganguli, Rahul; Sumner, James J.

    2015-05-01

    Renewable alternatives to fossil hydrocarbons for energy generation are of general interest for a variety of political, economic, environmental, and practical reasons. In particular, energy from biomass has many advantages, including safety, sustainability, and the ability to be scavenged from native ecosystems or from waste streams. Microbial fuel cells (MFCs) can take advantage of microorganism metabolism to efficiently use sugar and other biomolecules as fuel, but are limited by low power densities. In contrast, direct alcohol fuel cells (DAFCs) take advantage of proton exchange membranes (PEMs) to generate electricity from alcohols at much higher power densities. Here, we investigate a novel bio-hybrid fuel cell design prepared using commercial off-the-shelf DAFCs. In the bio-hybrid fuel cells, biomass such as sugar is fermented by yeast to ethanol, which can be used to fuel a DAFC. A separation membrane between the fermentation and the DAFC is used to purify the fermentate while avoiding any parasitic power losses. However, shifting the DAFCs from pure alcohol-water solutions to filtered fermented media introduces complications related to how the starting materials, fermentation byproducts, and DAFC waste products affect both the fermentation and the long-term DAFC performance. This study examines the impact of separation membrane pore size, fermentation/fuel cell byproducts, alcohol and salt concentrations, and load resistance on fuel cell performance. Under optimized conditions, the performance obtained is comparable to that of a similar DAFC run with a pure alcohol-water mixture. Additionally, the modified DAFC can provide useable amounts of power for weeks.

  14. Dry Storage Demonstration for High-Burnup Spent Nuclear Fuel-Feasibility Study

    SciTech Connect

    McKinnon, Mikal A. ); Cunningham, Mitchel E. )

    2003-09-09

    Initially, casks for dry storage of spent fuel were licensed for assembly-average burnup of about 35 GWd/MTU. Over the last two decades, the discharge burnup of fuel has increased steadily and now exceeds 45 GWd/MTU. With spent fuel burnups approaching the licensing limits (peak rod burnup of 62 GWd/MTU for pressurized water reactor fuel) and some lead test assemblies being burned beyond this limit, a need for a confirmatory dry storage demonstration program was first identified after the publication in May 1999 of the U.S. Nuclear Regulatory Commissions (NRC) Interim Staff Guidance 11 (ISG-11). With the publication in July 2002 of the second revision of ISG-11, the desirability for such a program further increased to obtain confirmatory data about the potential changes in cladding mechanical properties induced by dry storage, which would have implications to the transportation, handling, and disposal of high-burnup spent fuel. While dry storage licenses have kept pace with reactor discharge burnups, transportation licenses have not and are considered on a case by case basis. Therefore, this feasibility study was performed to examine the options available for conducting a confirmatory experimental program supporting the dry storage, transportation, and disposal of spent nuclear fuel with burnups well in excess of 45 GWd/MTU.

  15. A comparative study on the wear behaviors of cladding candidates for accident-tolerant fuel

    NASA Astrophysics Data System (ADS)

    Lee, Young-Ho; Byun, Thak Sang

    2015-10-01

    Accident-tolerant fuels are expected to have considerably longer coping time to respond to the loss of active cooling under severe accidents and, at the same time, have comparable or improved fuel performance during normal operation. The wear resistance of accident tolerant fuels, therefore, needs to be examined to determine the applicability of these cladding candidates to the current operating PWRs because the most common failure of nuclear fuel claddings is still caused by grid-to-rod fretting during normal operations. In this study, reciprocating sliding wear tests on three kinds of cladding candidates for accident-tolerant fuels have been performed to investigate the tribological compatibilities of self-mated cladding candidates and to determine the direct applicability of conventional Zirconium-based alloys as supporting structural materials. The friction coefficients of the cladding candidates are strongly influenced by the test environments and coupled materials. The wear test results under water lubrication conditions indicate that the supporting structural materials for the cladding candidates of accident-tolerant fuels need to be replaced with the same cladding materials instead of using conventional Zirconium-based alloys.

  16. 105KE and 105KW Basins fuel and sludge consolidation study, summary report

    SciTech Connect

    Gant, R.G.

    1994-09-20

    This study is a summary report that examines and evaluates the feasibility of consolidating irradiated fuel and sludge currently in KE Basin with that in the KW Basin. This study was conducted in support of TPA Milestone (target date) M-34-00-T03. The report summarizes three supporting engineering studies involving: (1) spent fuel consolidation into the single basin, (2) transport of the encapsulated fuel between KE and KW Basins, and (3) dispositioning contaminated water remaining in KE Basin. From the three reports, and preferred storage method, transfer method and water disposition method were defined. These consolidation methods were then evaluated against the no action alternative of continued storage using both KE and KW Basins. The report concluded that the fuel and sludge currently stored in KE Basin not be consolidated in the KW Basin, primarily due to increased cost and radiation exposure required to consolidate the fuel and sludge. Consolidation is more attractive for storage periods beyond the year 2002, which is the study period of the report.

  17. Numerical Study on Influence of Cross Flow on Rewetting of AHWR Fuel Bundle

    PubMed Central

    Kumar, Mithilesh; Mukhopadhyay, D.; Ghosh, A. K.; Kumar, Ravi

    2014-01-01

    Numerical study on AHWR fuel bundle has been carried out to assess influence of circumferential and cross flow rewetting on the conduction heat transfer. The AHWR fuel bundle quenching under accident condition is designed primarily with radial jets at several axial locations. A 3D (r, θ, z) transient conduction fuel pin model has been developed to carry out the study with a finite difference method (FDM) technique with alternating direction implicit (ADI) scheme. The single pin has been considered to study effect of circumferential conduction and multipins have been considered to study the influence of cross flow. Both analyses are carried out with the same fluid temperature and heat transfer coefficients as boundary conditions. It has been found from the analyses that, for radial jet, the circumferential conduction is significant and due to influence of overall cross flow the reductions in fuel temperature in the same quench plane in different rings are different with same initial surface temperature. Influence of cross flow on rewetting is found to be very significant. Outer fuel pins rewetting time is higher than inner. PMID:24672341

  18. Study of operational parameters impacting helicopter fuel consumption. [using computer techniques (computer programs)

    NASA Technical Reports Server (NTRS)

    Cross, J. L.; Stevens, D. D.

    1976-01-01

    A computerized study of operational parameters affecting helicopter fuel consumption was conducted as an integral part of the NASA Civil Helicopter Technology Program. The study utilized the Helicopter Sizing and Performance Computer Program (HESCOMP) developed by the Boeing-Vertol Company and NASA Ames Research Center. An introduction to HESCOMP is incorporated in this report. The results presented were calculated using the NASA CH-53 civil helicopter research aircraft specifications. Plots from which optimum flight conditions for minimum fuel use that can be obtained are presented for this aircraft. The results of the study are considered to be generally indicative of trends for all helicopters.

  19. Computational study of the influence of some systematic factors on the fuel temperature in a very high temperature gas-cooled reactor with prismatic fuel assemblies

    SciTech Connect

    Sedov, A. A.; Frolov, A. A.

    2011-12-15

    The influence of the main systematic factors of overheating (such as nonuniformity of power density and cold leaks of coolant) on the fuel temperatures in a very high temperature gas-cooled reactor NGNP (Next Generation Nuclear Plant) with prismatic fuel blocks is studied. The results of computations show a high sensitivity of the fuel temperatures to systematic factors of overheating. This circumstance indicates the necessity of high-precision three-dimensional modeling of the gas dynamics and heat transfer in the core when designing this type of reactor.

  20. A parametric study of staged fuel injector configurations for scramjet applications

    NASA Technical Reports Server (NTRS)

    Weidner, E. H.; Drummond, J. P.

    1981-01-01

    A parametric study of staged (multiple) perpendicular fuel injector configurations has been conducted using a computer code which solves the two-dimensional elliptic Navier-Stokes equations. The program computes the turbulent mixing and reaction of hydrogen fuel and air and allows the study of separated regions of the flow immediately preceding and following the injectors. The validity of the code is demonstrated in a cold flow helium injection study with a single injector. Results are presented that describe the flow field near opposing staged injectors over a range of parameters. Parameters that are varied include injector size, fuel split, and distance between injectors. Comparisons of the configurations are made to assess their mixing and potential flame-holding qualities.

  1. Importance of pressure gradient in solid oxide fuel cell electrodes for modeling study

    NASA Astrophysics Data System (ADS)

    Ni, Meng; Leung, Dennis Y. C.; Leung, Michael K. H.

    The pressure gradients in the electrodes of a solid oxide fuel cell (SOFC) are frequently neglected without any justification in calculating the concentration overpotentials of the SOFC electrodes in modeling studies. In this short communication, a comparative study has been conducted to study the effect of pressure gradients on mass transfer and the resulting concentration overpotentials of an SOFC running on methane (CH 4) fuel. It is found that the pressure gradients in both anode and cathode are significant in the fuel cell electrochemical activities. Neglecting the anode pressure gradient in the calculation can lead to underestimation of the concentration overpotential by about 20% at a typical current density of 5000 A m -2 and at a temperature of 1073 K. The deviation can be even larger at a higher temperature. At the cathode, neglecting the pressure gradient can result in overestimation of the concentration overpotential by about 10% under typical working conditions.

  2. Feasibility study of a mini fuel cell to detect interference from a cellular phone

    NASA Astrophysics Data System (ADS)

    Abdullah, M. O.; Gan, Y. K.

    Fuel cells produce electricity without involving combustion processes. They generate no noise, vibration or air pollution and are therefore suitable for use in many vibration-free power-generating applications. In this study, a mini alkaline fuel cell signal detector system has been designed, constructed and tested. The initial results have shown the applicability of such system for used as an indicator of signal disturbance from cellular phones. A small disturbance even at 4 mV cm -1, corresponding to an amplitude of 12-18 mG in terms of electromagnetic field, can be well detected by such a device. Subsequently, a thermodynamics model has been developed to provide a parametric study by simulation to show the likely performance of the fuel cell alone in other environments. As such the model can provide many useful generic design data for alkaline fuel cells. Two general conclusions can be drawn from the present theoretical study: (i) fuel cell performance increases with temperature, pressure and correction factor, C f; (ii) the temperature factor (E/ T) increases with increasing temperature and with increasing pressure factor.

  3. Compatibility Study of Protective Relaying in a Grid-Connected Fuel Cell

    SciTech Connect

    Staunton, R.H.

    2004-04-15

    A 200-kW fuel cell produced by International Fuel Cells (IFC), a United Technologies Company, began operation at the National Transportation Research Center (NTRC) in early June 2003. The NTRC is a joint Oak Ridge National laboratory (ORNL) and University of Tennessee research facility located in Knoxville, Tennessee. This research activity investigated the protective relaying functions of this fully commercialized fuel cell power plant, which uses ''synthesized'' protective relays. The project's goal is to characterize the compatibility between the fuel cell's interconnection protection system and the local distribution system or electric power system (EPS). ORNL, with assistance from the Electric Power Research Institute-Power Electronics Applications Center (EPRI-PEAC) in Knoxville, Tennessee, monitored and characterized the system compatibility over a period of 6 months. Distribution utility engineers are distrustful of or simply uncomfortable with the protective relaying and hardware provided as part of distributed generation (DG) plants. Part of this mistrust is due to the fact that utilities generally rely on hardware from certain manufacturers whose reliability is well established based on performance over many years or even decades. Another source of concern is the fact that fuel cells and other types of DG do not use conventional relays but, instead, the protective functions of conventional relays are simulated by digital circuits in the distributed generator's grid interface control unit. Furthermore, the testing and validation of internal protection circuits of DG are difficult to accomplish and can be changed by the vendor at any time. This study investigated and documented the safety and protective relaying present in the IFC fuel cell, collected data on the operation of the fuel cell, recorded event data during EPS disturbances, and assessed the compatibility of the synthesized protective circuits and the local distribution system. The project also

  4. A Study of NO{sub x} Reduction by Fuel Injection Recirculation

    SciTech Connect

    Feese, J.J.; Turns, S.R.

    1996-08-01

    Flue-gas recirculation (FGR) is a well-known method used to control oxides of nitrogen (NO{sub X}) in industrial burner applications. Recent small- and large-scale experiments in natural-gas fired boilers have shown that introducing the recirculated flue gases with the fuel results in a much greater reduction in NO{sub X}, per unit mass of gas recirculated, in comparison to introducing the flue gases with the combustion air. That fuel injection recirculation (FIR) is more effective than windbox FGR is quite remarkable. At present, however, there is no definitive understanding of why FIR is more effective than conventional FGR. The objective of the present investigation is to ascertain whether or not chemical and/or molecular transport effects alone can explain the differences in NO{sub X} reduction observed between FIR and FGR by studying laminar diffusion flames. The purpose of studying laminar flames is to isolate chemical effects from the effects of turbulent mixing and heat transfer, which are inherent in practical boilers. Numerical simulations of H{sub 2}-air and CH{sub 4}-air counterflow diffusion flames using full kinetics were performed and NO{sub X} emission indices calculated for various conditions. Studies were conducted in which a N{sub 2} diluent was added either on the fuel- or air-side of the flame for conditions of either fixed initial velocities or fixed fuel mass flux. Results from these simulation studies indicate that a major factor in diluent effectiveness is the differential effect on flame zone residence times associated with fuel-side verses air-side dilution. Simulations in which flow velocities were fixed as diluent was added either to the air or fuel stream showed lower NO{sub X} emissions for air-side dilution; however, if instead, fuel mass fluxes were fixed as diluent was added, which results in an increase in the velocity of the streams, fuel-side dilution was more effective. These results were independent of whether H{sub 2} or Ch

  5. CATCOM catalyst 5 atm 1000 hour aging study using No. 2 fuel oil

    NASA Technical Reports Server (NTRS)

    Osgerby, I. T.; Olson, B. A.; Lee, H. C.

    1980-01-01

    The durability of the CATCOM catalyst for use in catalytically supported thermal combustion has been demonstrated at 5 atm, complementing a previous 1000 hour durability study at 1 atm. Both of these studies were conducted at about 640 K air preheat temperature at a reference velocity of about 14 m/s; the adiabatic flame temperature of the fuel/air mixture was about 1530 K. The catalyst proved to be capable of low emissions operations after 1000 hours of diesel fuel aging. However, more severe deactivation occurred in the 5 atm test; this was attributed to a loss in kinetic (ignition) activity.

  6. Study on Fuel Cell Network System Considering Reduction in Fuel Cell Capacity Using Load Leveling and Heat Release Loss

    NASA Astrophysics Data System (ADS)

    Obara, Shin'ya; Kudo, Kazuhiko

    Reduction in fuel cell capacity linked to a fuel cell network system is considered. When the power demand of the whole network is small, some of the electric power generated by the fuel cell is supplied to a water electrolysis device, and hydrogen and oxygen gases are generated. Both gases are compressed with each compressor and they are stored in cylinders. When the electric demand of the whole network is large, both gases are supplied to the network, and fuel cells are operated by these hydrogen and oxygen gases. Furthermore, an optimization plan is made to minimize the quantity of heat release of the hot water piping that connects each building. Such an energy network is analyzed assuming connection of individual houses, a hospital, a hotel, a convenience store, an office building, and a factory. Consequently, compared with the conventional system, a reduction of 46% of fuel cell capacity is expected.

  7. Nuclear fuel cycle assessment of India: A technical study for U.S.-India cooperation

    NASA Astrophysics Data System (ADS)

    Krishna, Taraknath Woddi Venkat

    The recent civil nuclear cooperation proposed by the Bush Administration and the Government of India has heightened the necessity of assessing India's nuclear fuel cycle inclusive of nuclear materials and facilities. This agreement proposes to change the long-standing U.S. policy of preventing the spread of nuclear weapons by denying nuclear technology transfer to non-NPT signatory states. The nuclear tests in 1998 have convinced the world community that India would never relinquish its nuclear arsenal. This has driven the desire to engage India through civilian nuclear cooperation. The cornerstone of any civilian nuclear technological support necessitates the separation of military and civilian facilities. A complete nuclear fuel cycle assessment of India emphasizes the entwinment of the military and civilian facilities and would aid in moving forward with the separation plan. To estimate the existing uranium reserves in India, a complete historical assessment of ore production, conversion, and processing capabilities was performed using open source information and compared to independent reports. Nuclear energy and plutonium production (reactor- and weapons-grade) was simulated using declared capacity factors and modern simulation tools. The three-stage nuclear power program entities and all the components of civilian and military significance were assembled into a flowsheet to allow for a macroscopic vision of the Indian fuel cycle. A detailed view of the nuclear fuel cycle opens avenues for technological collaboration. The fuel cycle that grows from this study exploits domestic thorium reserves with advanced international technology and optimized for the existing system. To utilize any appreciable fraction of the world's supply of thorium, nuclear breeding is necessary. The two known possibilities for production of more fissionable material in the reactor than is consumed as fuel are fast breeders or thermal breeders. This dissertation analyzes a thermal

  8. Study of fuel cell co-generation systems applied to a dairy industry

    NASA Astrophysics Data System (ADS)

    Leal, Elisângela M.; Silveira, José Luz

    This paper presents a methodology for the study of a molten carbonate fuel cell co-generation system. This system is applied to a dairy industry of medium size that typically demands 2100 kW of electricity, 8500 kg/h of saturated steam ( P=1.08 MPa) and 2725 kW of cold water production. Depending on the associated recuperation equipment, the co-generation system permits the recovery of waste heat, which can be used for the production of steam, hot and cold water, hot and cold air. In this study, a comparison is made between two configurations of fuel cell co-generation systems (FCCS). The plant performance has been evaluated on the basis of fuel utilisation efficiency and each system component evaluated on the basis of second law efficiency. The energy analysis presented shows a fuel utilisation efficiency of about 87% and exergy analysis shows that the irreversibilities in the combustion chamber of the plant are significant. Further, the payback period estimated for the fuel cell investment between US 1000 and US 1500/kW is about 3 and 6 years, respectively.

  9. A comparative study of emission motorcycle with gasoline and CNG fuel

    NASA Astrophysics Data System (ADS)

    Sasongko, M. N.; Wijayanti, W.; Rahardja, R. A.

    2016-03-01

    A comparison of the exhaust emissions of the engine running gasoline and Compressed Natural Gas have been performed in this study. A gasoline engine 4 stroke single-cylinder with volume of 124.8 cc and compression ratio of 9.3:1 was converted to a CNG gaseous engine. The fuel injector was replaced with a solenoid valve system for injecting CNG gas to engine. The concentrations of CO, CO2, O2 and HC in the exhaust gas of engine were measured over the range of fuel flow rate from 25.32 mg/s to 70.22 mg/s and wide range of Air Fuel Ratio. The comparative analysis of this study showed that CNG engine has a lower HC, CO2 and CO emission at the stoichiometry mixture of fuel and air combustion. The emissions increased when the Air-Fuel ratio was switched from the stoichiometry condition. Moreover, CNG engine produced a lower HC and CO emission compared to the gasoline for difference air flow rate. The average of HC and CO emissions of the CNG was 92 % and 78 % lower than that of the gasoline

  10. Cost Study for Manufacturing of Solid Oxide Fuel Cell Power Systems

    SciTech Connect

    Weimar, Mark R.; Chick, Lawrence A.; Gotthold, David W.; Whyatt, Greg A.

    2013-09-30

    Solid oxide fuel cell (SOFC) power systems can be designed to produce electricity from fossil fuels at extremely high net efficiencies, approaching 70%. However, in order to penetrate commercial markets to an extent that significantly impacts world fuel consumption, their cost will need to be competitive with alternative generating systems, such as gas turbines. This report discusses a cost model developed at PNNL to estimate the manufacturing cost of SOFC power systems sized for ground-based distributed generation. The power system design was developed at PNNL in a study on the feasibility of using SOFC power systems on more electric aircraft to replace the main engine-mounted electrical generators [Whyatt and Chick, 2012]. We chose to study that design because the projected efficiency was high (70%) and the generating capacity was suitable for ground-based distributed generation (270 kW).

  11. Studies on Methanol Crossover in Liquid-Feed Direct Methanol Pem Fuel Cells

    NASA Technical Reports Server (NTRS)

    Narayanan, S. R.

    1995-01-01

    The performance of liquid feed direct methanol fuel cells using various types of Nafion membranes as the solid polymer electrolyte have been studied. The rate of fuel crossover and electrical performance has been measured for cells with Nafion membranes of various thicknesses and equivalent weights. The crossover rate is found to decrease with increasing thickness and applied current. The dependence of crossover rate on current density can be understood in terms of a simple linear diffusion model which suggests that the crossover rate can be influenced by the electrode structure in addition to the membrane. The studies suggest that Nafion EW 1500 is a very promising alternate to Nafion EW 1100 for direct methanol fuel cells.

  12. Research and development of Proton-Exchange-Membrane (PEM) fuel cell system for transportation applications. Fuel cell infrastructure and commercialization study

    SciTech Connect

    1996-11-01

    This paper has been prepared in partial fulfillment of a subcontract from the Allison Division of General Motors under the terms of Allison`s contract with the U.S. Department of Energy (DE-AC02-90CH10435). The objective of this task (The Fuel Cell Infrastructure and Commercialization Study) is to describe and prepare preliminary evaluations of the processes which will be required to develop fuel cell engines for commercial and private vehicles. This report summarizes the work undertaken on this study. It addresses the availability of the infrastructure (services, energy supplies) and the benefits of creating public/private alliances to accelerate their commercialization. The Allison prime contract includes other tasks related to the research and development of advanced solid polymer fuel cell engines and preparation of a demonstration automotive vehicle. The commercialization process starts when there is sufficient understanding of a fuel cell engine`s technology and markets to initiate preparation of a business plan. The business plan will identify each major step in the design of fuel cell (or electrochemical) engines, evaluation of the markets, acquisition of manufacturing facilities, and the technical and financial resources which will be required. The process will end when one or more companies have successfully developed and produced fuel cell engines at a profit. This study addressed the status of the information which will be required to prepare business plans, develop the economic and market acceptance data, and to identify the mobility, energy and environment benefits of electrochemical or fuel cell engines. It provides the reader with information on the status of fuel cell or electrochemical engine development and their relative advantages over competitive propulsion systems. Recommendations and descriptions of additional technical and business evaluations that are to be developed in more detail in Phase II, are included.

  13. Scoping studies of the alternative options for defueling, packaging, shipping, and disposing of the TMI-2 spent fuel core

    SciTech Connect

    Anderson, Robert T.

    1980-09-01

    A portion of this fuel will be shipped to nuclear facilities to perform detailed physical examinations. Removal of this fuel from the TMI-2 core is also a significant step in the eventual cleanup of this facility. The report presents a scoping study of the technical operations required for defueling and canning. The TMI fuel when canned could be stored in the spent fuel storage pool. After a period of on-site storage, it is expected that the bulk of the fuel will be shipped off-site for either storage or reprocessing. Evaluation is made of the technical, economic, and institutional factors associated with alternate approaches to disposition of this fuel. Recommendations are presented concerning future generic development tasks needed for the defueling, packaging, on-site shipping of this fuel.

  14. Study of Compton suppression for use in spent nuclear fuel assay

    NASA Astrophysics Data System (ADS)

    Bender, Sarah

    The focus of this study has been to assess Compton suppressed gamma-ray detection systems for the multivariate analysis of spent nuclear fuel. This objective has been achieved using direct measurement of samples of irradiated fuel elements in two geometrical configurations with Compton suppression systems. In order to address the objective to quantify the number of additionally resolvable photopeaks, direct Compton suppressed spectroscopic measurements of spent nuclear fuel in two configurations were performed: as intact fuel elements and as dissolved feed solutions. These measurements directly assessed and quantified the differences in measured gamma-ray spectrum from the application of Compton suppression. Several irradiated fuel elements of varying cooling time from the Penn State Breazeale Reactor spent fuel inventory were measured using three Compton suppression systems that utilized different primary detectors: HPGe, LaBr3, and NaI(Tl). The application of Compton suppression using a LaBr3 primary detector to the measurement of the current core fuel element, which presented the highest count rate, allowed four additional spectral features to be resolved. In comparison, the HPGe-CSS was able to resolve eight additional photopeaks as compared to the standalone HPGe measurement. Measurements with the NaI(Tl) primary detector were unable to resolve any additional peaks, due to its relatively low resolution. Samples of Approved Test Material (ATM) commercial fuel elements were obtained from Pacific Northwest National Laboratory. The samples had been processed using the beginning stages of the PUREX method and represented the unseparated feed solution from a reprocessing facility. Compton suppressed measurements of the ATM fuel samples were recorded inside the guard detector annulus, to simulate the siphoning of small quantities from the main process stream for long dwell measurement periods. Photopeak losses were observed in the measurements of the dissolved ATM

  15. Indoor solid fuel use and tuberculosis in China: a matched case-control study

    PubMed Central

    2011-01-01

    Background China ranks second among the 22 high burden countries for tuberculosis. A modeling exercise showed that reduction of indoor air pollution could help advance tuberculosis control in China. However, the association between indoor air pollution and tuberculosis is not yet well established. A case control study was conducted in Anhui, China to investigate whether use of solid fuel is associated with tuberculosis. Methods Cases were new sputum smear positive tuberculosis patients. Two controls were selected from the neighborhood of each case matched by age and sex using a pre-determined procedure. A questionnaire containing demographic information, smoking habits and use of solid fuel for cooking or heating was used for interview. Solid fuel (coal and biomass) included coal/lignite, charcoal, wood, straw/shrubs/grass, animal dung, and agricultural crop residue. A household that used solid fuel either for cooking and (/or) heating was classified as exposure to combustion of solid fuel (indoor air pollution). Odds ratios and their corresponding 95% confidence limits for categorical variables were determined by Mantel-Haenszel estimate and multivariate conditional logistic regression. Results There were 202 new smear positive tuberculosis cases and 404 neighborhood controls enrolled in this study. The proportion of participants who used solid fuels for cooking was high (73.8% among cases and 72.5% among controls). The majority reported using a griddle stove (85.2% among cases and 86.7% among controls), had smoke removed by a hood or chimney (92.0% among cases and 92.8% among controls), and cooked in a separate room (24.8% among cases and 28.0% among controls) or a separate building (67.8% among cases and 67.6% among controls). Neither using solid fuel for cooking (odds ratio (OR) 1.08, 95% CI 0.62-1.87) nor using solid fuel for heating (OR 1.04, 95% CI 0.54-2.02) was significantly associated with tuberculosis. Determinants significantly associated with

  16. The national Fire and Fire Surrogate study: Effects of fuel reduction methods on forest vegetation structure and fuels

    USGS Publications Warehouse

    Schwilk, D.W.; Keeley, J.E.; Knapp, E.E.; Mciver, J.; Bailey, J.D.; Fettig, C.J.; Fiedler, C.E.; Harrod, R.J.; Moghaddas, J.J.; Outcalt, K.W.; Skinner, C.N.; Stephens, S.L.; Waldrop, T.A.; Yaussy, D.A.; Youngblood, A.

    2009-01-01

    Changes in vegetation and fuels were evaluated from measurements taken before and after fuel reduction treatments (prescribed fire, mechanical treatments, and the combination of the two) at 12 Fire and Fire Surrogate (FFS) sites located in forests with a surface fire regime across the conterminous United States. To test the relative effectiveness of fuel reduction treatments and their effect on ecological parameters we used an informationtheoretic approach on a suite of 12 variables representing the overstory (basal area and live tree, sapling, and snag density), the understory (seedling density, shrub cover, and native and alien herbaceous species richness), and the most relevant fuel parameters for wildfire damage (height to live crown, total fuel bed mass, forest floor mass, and woody fuel mass). In the short term (one year after treatment), mechanical treatments were more effective at reducing overstory tree density and basal area and at increasing quadratic mean tree diameter. Prescribed fire treatments were more effective at creating snags, killing seedlings, elevating height to live crown, and reducing surface woody fuels. Overall, the response to fuel reduction treatments of the ecological variables presented in this paper was generally maximized by the combined mechanical plus burning treatment. If the management goal is to quickly produce stands with fewer and larger diameter trees, less surface fuel mass, and greater herbaceous species richness, the combined treatment gave the most desirable results. However, because mechanical plus burning treatments also favored alien species invasion at some sites, monitoring and control need to be part of the prescription when using this treatment. ?? 2009 by the Ecological Society of America.

  17. Fuel flexible fuel injector

    DOEpatents

    Tuthill, Richard S; Davis, Dustin W; Dai, Zhongtao

    2015-02-03

    A disclosed fuel injector provides mixing of fuel with airflow by surrounding a swirled fuel flow with first and second swirled airflows that ensures mixing prior to or upon entering the combustion chamber. Fuel tubes produce a central fuel flow along with a central airflow through a plurality of openings to generate the high velocity fuel/air mixture along the axis of the fuel injector in addition to the swirled fuel/air mixture.

  18. Feasibility study: fuel cell cogeneration in a water pollution control facility. Final report

    SciTech Connect

    Not Available

    1980-02-01

    A conceptual design study was conducted to investigate the technical and economic feasibility of a cogeneration fuel cell power plant operating in a large water pollution control facility. In this particular application, the fuel cell power plant would use methane-rich digester gas from the water pollution control facility as a fuel feedstock to provide electrical and thermal energy. Several design configurations were evaluated. These configurations were comprised of combinations of options for locating the fuel cell power plant at the site, electrically connecting it with the water pollution control facility, using the rejected power plant heat, supplying fuel to the power plant, and for ownership and operation. A configuration was selected which met institutional/regulatory constraints and provided a net cost savings to the industry and the electric utility. The displacement of oil and coal resulting from the Bergen County Utilities Authority application was determined. A demonstration program based on the selected configuration was prepared to describe the scope of work, organization, schedules, and costs from preliminary design through actual tests and operation. The potential market for nationwide application of the concept was projected, along with the equivalent oil displacement resulting from estimated commercial application.

  19. Comparative study of two different powertrains for a fuel cell hybrid bus

    NASA Astrophysics Data System (ADS)

    Gao, Dawei; Jin, Zhenhua; Zhang, Junzhi; Li, Jianqiu; Ouyang, Minggao

    2016-07-01

    The powertrain plays an essential role in improving the tractive performance and the fuel consumption of fuel cell hybrid vehicles. This paper presents a comparative study of two different powertrains for fuel cell hybrid buses. The significant difference between the two powertrains lies in the types and arrangements of the electrical motor. One powertrain employs an induction motor to drive the vehicle, while the other powertrain adopts two permanent magnetic synchronous motors for near-wheel propulsion. Besides, the tiny difference between the proposed powertrain is the supply path of the fuel cell accessories, which can have an effect on the powertrain efficiency. The component parameters and energy management strategies for the two powertrain are determined. The fuel cell hybrid buses equipped with the two powertrains are developed, and some road tests are achieved, according to the chosen procedures or driving cycles. The paper focuses on the tractive performance and energy analysis of the powertrains based on the testing results. Finally, the paper summarizes the relative merits of the proposed powertrains.

  20. Fuel-Specific Effect of Exhaust Gas Residuals on HCCI Combustion: A Modeling Study

    SciTech Connect

    Szybist, James P

    2008-01-01

    A modeling study was performed to investigate fuel-specific effects of exhaust gas recirculation (EGR) components on homogeneous charge compression ignition (HCCI) combustion at conditions relevant to the negative valve overlap (NVO) strategy using CHEMKIN-PRO. Four single-component fuels with well-established kinetic models were chosen: n-heptane, iso-octane, ethanol, and toluene. These fuels were chosen because they span a wide range of fuel chemistries, and produce a wide compositions range of complete stoichiometric products (CSP). The simulated engine conditions combined a typical spark ignition engine compression ratio (11.34) and high intake charge temperatures (500-550 K) that are relevant to NVO HCCI. It was found that over the conditions investigated, all the fuels had overlapping start of combustion (SOC) phasing, despite the wide range in octane number (RON = 0 to 120). The effect of the EGR components CO2 and H2O was to suppress the compression temperature because of their higher heat capacities, which retarded SOC. For a concentration of O2 higher than the stoichiometric amount, or excess O2, there was an effect of advancing SOC for n-heptane, iso-octane, and toluene, but SOC for ethanol was not advanced. Low temperature heat release (LTHR) for n-heptane was also found to be highly dependent on excess O2, and mild endothermic reaction was observed for cases when excess O2 was not present.

  1. Experimental studies of thermal and chemical interactions between oxide and silicide nuclear fuels with water

    SciTech Connect

    farahani, A.A.; Corradini, M.L.

    1995-09-01

    Given some transient power/cooling mismatch is a nuclear reactor and its inability to establish the necessary core cooling, energetic fuel-coolant interactions (FCI`s commonly called `vapor explosions`) could occur as a result of the core melting and coolant contact. Although a large number of studies have been done on energetic FCI`s, very few experiments have been performed with the actual fuel materials postulated to be produced in severe accidents. Because of the scarcity of well-characterized FCI data for uranium allows in noncommercial reactors (cermet and silicide fuels), we have conducted a series of experiments to provide a data base for the foregoing materials. An existing 1-D shock-tube facility was modified to handle depleted radioactive materials (U{sub 3}O{sub 8}-Al, and U{sub 3}Si{sub 2}-Al). Our objectives have been to determine the effects of the initial fuel composition and temperature and the driving pressure (triggering) on the explosion work output, dynamic pressures, transient temperatures, and the hydrogen production. Experimental results indicate limited energetics, mainly thermal interactions, for these fuel materials as compared to aluminum where more chemical reactions occur between the molten aluminum and water.

  2. A study of the effect of fabrication variables on the void content and quality of fuel plates

    SciTech Connect

    Wiencek, T.C.

    1986-10-01

    The control of void content and quality of dispersion type fuel plates fabricated for research and test reactors are issues of concern to plate fabricators. These two variables were studied by examining the data for various geometries of fuel plates fabricated at ANL. It was found that the porosity of a fuel plate can be increased by: (1) decreasing the fuel particle size, (2) increasing the fuel particle surface roughness, (3) increasing the matrix strength, (4) decreasing the rolling temperature, (5) decreasing the final fuel zone thickness, and (6) increasing the volume percentage of the fuel. Porosity formation is controlled by bulk movement and deformation and/or fracture of particles. The most important factor is the flow stress of the matrix material. Lowering the flow stress will decrease the plate porosity. The percentage of plates with fuel-out-of-zone is a function of the fuel material and the loading. The highest percentage of plates with fuel-out-of-zone were those with U3Si2 which is at this time the most commonly used silicide fuel.

  3. Internal voltage control of hydrogen-oxygen fuel cells: Feasibility study

    NASA Technical Reports Server (NTRS)

    Prokopius, P. R.

    1975-01-01

    An experimental study was conducted to assess the feasibility of internal voltage regulation of fuel cell systems. Two methods were tested. In one, reactant partial pressure was used as the voltage control parameter and in the other reactant total pressure was used for control. Both techniques were breadboarded and tested on a single alkaline-electrolyte fuel cell. Both methods were found to be possible forms of regulation, however, of the two the total pressure technique would be more efficient, simpler to apply and would provide better transient characteristics.

  4. Economic Study of Spent Nuclear Fuel Storage and Reprocessing Practices in Russia

    SciTech Connect

    C. E. Singer; G. H. Miley

    1997-10-01

    This report describes a study of nuclear power economics in Russia. It addresses political and institutional background factors which constrain Russia's energy choices in the short and intermediate run. In the approach developed here, political and institutional factors might dominate short-term decisions, but the comparative costs of Russia's fuel-cycle options are likely to constrain her long-term energy strategy. To this end, the authors have also formulated a set of policy questions which should be addressed using a quantitative decision modeling which analyzes economic costs for all major components of different fuel cycle options, including the evolution of uranium prices.

  5. Technical Approach and Results from the Fuels Pathway on an Alternative Selection Case Study

    SciTech Connect

    Bob Youngblood; Curtis Smith

    2013-09-01

    The report presents a detailed plan for conducting case studies to characterize probabilistic safety margins associated with different fuel cladding types in a way that supports a valid comparison of different fuels' performance. Recent work performed in other programs is described briefly and used to illustrate the challenges posed by characterization of margin in a probabilistic way. It is additionally pointed out that consistency of evaluation of performance across different cladding types is not easy to assure; a process for achieving the needed consistency is described.

  6. Validation studies based on critical experiments performed with fuel pin arrays moderated by Pu + U solutions

    SciTech Connect

    Smolen, G.R.; Matsumoto, T. )

    1989-01-01

    This paper outlines the results of a calculational study that was performed to validate the SCALE computer code system using data from critical experiments performed with fuel pin arrays moderated by mixed Pu + U aqueous solutions. A companion paper describes the experiments and discusses the criticality data that were obtained. These experimental activities are part of a joint exchange program between the US Department of Energy (DOE) and the Power Reactor and Nuclear Fuel Development Corporation of Japan in the area of criticality data development. The Consolidated fuel Reprocessing Program (CFRP) at Oak Ridge National Laboratory (ORNL) manages the program for the DOE. The experiments were conducted at the Battelle Pacific Northwest Laboratories-Critical Mass Laboratory (PNL-CML).

  7. Applications of the thermogravimetric analysis in the study of fossil fuels

    SciTech Connect

    Huang, He; Wang, Keyu; Wang, Shaojie; Klein, M.T.; Calkins, W.H.

    1996-12-31

    Thermogravimetric analysis (TGA) of coal and resid liquids and coal and resid solid residues, produced in coal liquefaction and coal- derived resid hydroprocessing in SCTBR (short contact time batch reactor), provides a sensitive, rapid, reproducible means of studying kinetics and mechanisms of fossil fuel conversion processes. SimDis TGA and custom built TGA system for distillation provide unique means to characterize liquid fuels for boiling point distribution. TGA provides information about various weight loss processes that can be a reflection of physical and chemical structure of fossil fuel samples. This technique can also yield TG scanning parameters, such as volatile matter, fixed carbon, ash, etc., for monitoring the conversion processes. One example is onset and rate of retrograde reactions during coal liquefaction.

  8. Phase 1 feasibility study of an integrated hydrogen PEM fuel cell system. Final report

    SciTech Connect

    Luczak, F.

    1998-03-01

    Evaluated in the report is the use of hydrogen fueled proton exchange membrane (PEM) fuel cells for devices requiring less than 15 kW. Metal hydrides were specifically analyzed as a method of storing hydrogen. There is a business and technical part to the study that were developed with feedback from each other. The business potential of a small PEM product is reviewed by examining the markets, projected sales, and required investment. The major technical and cost hurdles to a product are also reviewed including: the membrane and electrode assembly (M and EA), water transport plate (WTP), and the metal hydrides. It was concluded that the best potential stationary market for hydrogen PEM fuel cell less than 15 kW is for backup power use in telecommunications applications.

  9. Case Study: Fuel Cells Provide Combined Heat and Power at Verizon's Garden City Central Office

    SciTech Connect

    2010-12-01

    This case study describes how Verizon's Central Office in Garden City, NY, installed a 1.4-MW phosphoric acid fuel cell system as an alternative solution to bolster electric reliability, optimize the company's energy use, and reduce costs in an environmentally responsible manner.

  10. Impact of fuel and nitrogen prices on profitability of selected crops: A case study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increasing prices for fuel and nitrogen (N) fertilizer affect crop production decisions and profitability. Nitrogen response functions were estimated for corn (Zea mays L.), sugar beets (Beta vulgaris L.), dry beans (Phaseolus vulgaris L.), and malt barley (Hordeum vulgare L.) using data from studie...

  11. Neutronics and Depletion Methods for Parametric Studies of Fluoride Salt Cooled High Temperature Reactors with Slab Fuel Geometry and Multi-Batch Fuel Management Schemes

    SciTech Connect

    Cisneros, Anselmo T.; Ilas, Dan

    2012-01-01

    The Advanced High Temperature Reactor (AHTR) is a 3400 MWth fluoride salt cooled high temperature reactor (FHR) that uses TRISO particle fuel compacted into slabs rather than spherical fuel pebbles or cylindrical fuel compacts. Simplified methods are required for parametric design studies such that analyzing the entire feasible design space for an AHTR is tractable. These simplifications include fuel homogenization techniques to increase the speed of neutron transport calculations in depletion analysis and equilibrium depletion analysis methods to analyze systems with multi-batch fuel management schemes. This paper presents three elements of significant novelty. First, the reactivity-equivalent physical transformation (RPT) methodology usually applied in systems with coated particle fuel in cylindrical and spherical geometries was extended to slab geometries. Secondly, based on this newly developed RPT method for slab geometries, a methodology that uses Monte Carlo depletion approaches was further developed to search for the maximum discharge burnup in a multi-batch system by iteratively estimating the beginning of equilibrium cycle composition and sampling different discharge burnups. This iterative equilibrium depletion search (IEDS) method fully defines an equilibrium fuel cycle (keff, power, flux and composition evolutions across space and time), but is computationally demanding, although feasible on single-processor workstations. Finally, an analytical method, the non-linear reactivity model, was developed by expanding the linear reactivity model to include an arbitrary number of higher order terms to extrapolate single-batch depletion results to estimate the maximum discharge burnup and BOEC keff in systems with multi-batch fuel management schemes. Results from this method were benchmarked against equilibrium depletion analysis results using the IEDS.

  12. A Cross-Sectional Study of Household Biomass Fuel Use among a Periurban Population in Malawi

    PubMed Central

    Piddock, Katy C.; Gordon, Stephen B.; Ngwira, Andrew; Msukwa, Malango; Nadeau, Gilbert; Davis, Kourtney J.; Nyirenda, Moffat J.; Mortimer, Kevin

    2016-01-01

    Rationale The Global Burden of Disease Study suggests almost 3.5 million people die as a consequence of household air pollution every year. Respiratory diseases including chronic obstructive pulmonary disease and pneumonia in children are strongly associated with exposure to household air pollution. Smoke from burning biomass fuels for cooking, heating, and lighting is the main contributor to high household air pollution levels in low-income countries like Malawi. A greater understanding of biomass fuel use in Malawi should enable us to address household air pollution–associated communicable and noncommunicable diseases more effectively. Objectives To conduct a cross-sectional analysis of biomass fuel use and population demographics among adults in Blantyre, Malawi. Methods We used global positioning system–enabled personal digital assistants to collect data on location, age, sex, marital status, education, occupation, and fuel use. We describe these data and explore associations between demographics and reported fuel type. Measurements and Main Results A total of 16,079 adults participated (nine households refused); median age was 30 years, there was a similar distribution of men and women, 60% were married, and 62% received secondary school education. The most commonly reported occupation for men and women was “salaried employment” (40.7%) and “petty trader and marketing” (23.5%), respectively. Charcoal (81.5% of households), wood (36.5%), and electricity (29.1%) were the main fuels used at home. Only 3.9% of households used electricity exclusively. Lower educational and occupational attainment was associated with greater use of wood. Conclusions This large cross-sectional study has identified extensive use of biomass fuels in a typical sub-Saharan Africa periurban population in which women and people of lower socioeconomic status are disproportionately affected. Biomass fuel use is likely to be a major driver of existing communicable respiratory

  13. A neutronic feasibility study of the AP1000 design loaded with fully ceramic micro-encapsulated fuel

    SciTech Connect

    Liang, C.; Ji, W.

    2013-07-01

    A neutronic feasibility study is performed to evaluate the utilization of fully ceramic microencapsulated (FCM) fuel in the AP1000 reactor design. The widely used Monte Carlo code MCNP is employed to perform the full core analysis at the beginning of cycle (BOC). Both the original AP1000 design and the modified design with the replacement of uranium dioxide fuel pellets with FCM fuel compacts are modeled and simulated for comparison. To retain the original excess reactivity, ranges of fuel particle packing fraction and fuel enrichment in the FCM fuel design are first determined. Within the determined ranges, the reactor control mechanism employed by the original design is directly used in the modified design and the utilization feasibility is evaluated. The worth of control of each type of fuel burnable absorber (discrete/integral fuel burnable absorbers and soluble boron in primary coolant) is calculated for each design and significant differences between the two designs are observed. Those differences are interpreted by the fundamental difference of the fuel form used in each design. Due to the usage of silicon carbide as the matrix material and the fuel particles fuel form in FCM fuel design, neutron slowing down capability is increased in the new design, leading to a much higher thermal spectrum than the original design. This results in different reactivity and fission power density distributions in each design. We conclude that a direct replacement of fuel pellets by the FCM fuel in the AP1000 cannot retain the original optimum reactor core performance. Necessary modifications of the core design should be done and the original control mechanism needs to be re-designed. (authors)

  14. Study of unsteady flow conditions for slurry fuels

    SciTech Connect

    Ekmann, J.M.; Wildman, D.J.; Klinzing, G.E.

    1985-01-01

    During the past three years, transport characteristics of coal-water mixtures (CWMs) have been studied at the Pittsburgh Energy Technology Center. The effort has concentrated predominantly on studying flow conditions in straight horizontal and vertical sections, and to a lesser extent on studying the flow patterns around elbows of a one-inch-diameter loop and a two-inch-diameter loop. Steady-state flow was characterized for in-house prepared slurries and commercially prepared slurries. For lower concentrated slurries (55 wt % to 60 wt %) and coarse particle size distributions (50% finer than 75 microns), nonhomogeneous flow conditions were encountered across horizontal test sections. Since nonhomogeneous conditions existed in straight sections during steady-state flow, it was decided to further investigate flow conditions during changes in velocity (magnitude and direction). This paper concentrates on nonuniform flow conditions of two types. The first nonuniform flow condition arises from sudden increases in the magnitude of the flow velocity. Pressure measurements recorded at a fixed position in the vertical section of the two-inch-diameter loop during sudden changes in velocity can be analyzed via classic control theory to evaluate the dynamic properties of the CWM. The second nonuniform flow condition occurs as the CWM passes through a bend. Both long-radius bends and 90-degree elbows made of glass and steel have been studied. Pressure-loss data around the long-radius bends and elbows were analyzed with a modified version of the model developed by Ito for single-phase flow around bends. Flow patterns around glass bends and elbows were observed for slurries prepared of vinyl coating powder and water. They are described in an effort to increase understanding of the pressure-loss data. 8 refs., 11 figs., 1 tab.

  15. TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

    SciTech Connect

    Powers, Jeffrey James

    2011-11-30

    This study focused on creating a new tristructural isotropic (TRISO) coated particle fuel performance model and demonstrating the integration of this model into an existing system of neutronics and heat transfer codes, creating a user-friendly option for including fuel performance analysis within system design optimization and system-level trade-off studies. The end product enables both a deeper understanding and better overall system performance of nuclear energy systems limited or greatly impacted by TRISO fuel performance. A thorium-fueled hybrid fusion-fission Laser Inertial Fusion Energy (LIFE) blanket design was used for illustrating the application of this new capability and demonstrated both the importance of integrating fuel performance calculations into mainstream design studies and the impact that this new integrated analysis had on system-level design decisions. A new TRISO fuel performance model named TRIUNE was developed and verified and validated during this work with a novel methodology established for simulating the actual lifetime of a TRISO particle during repeated passes through a pebble bed. In addition, integrated self-consistent calculations were performed for neutronics depletion analysis, heat transfer calculations, and then fuel performance modeling for a full parametric study that encompassed over 80 different design options that went through all three phases of analysis. Lastly, side studies were performed that included a comparison of thorium and depleted uranium (DU) LIFE blankets as well as some uncertainty quantification work to help guide future experimental work by assessing what material properties in TRISO fuel performance modeling are most in need of improvement. A recommended thorium-fueled hybrid LIFE engine design was identified with an initial fuel load of 20MT of thorium, 15% TRISO packing within the graphite fuel pebbles, and a 20cm neutron multiplier layer with beryllium pebbles in flibe molten salt coolant. It operated

  16. Surface science studies on titania for solar fuel applications

    NASA Astrophysics Data System (ADS)

    Hadsell, Courtney Sara Mathews

    Titanium dioxide (titania) is a well-studied material for various applications including but not limited to, paint, sunscreen, pharmaceuticals and solar cell applications (photocatalysis.) It can be found in three main crystal forms; rutile, anatase, and brookite and this work will focus on the anatase form which has been heavily studied for its potential in dye sensitized solar cells (DSSCs.) I propose that aqueous and photo dye stability can be improved by taking special care to the exposed surface of anatase. Additionally, the theoretical maximum open circuit voltage of a DSSC is dependent upon which surface is exposed to the electrolyte. Previous works in this area have not been rigorous with respect to the surface and morphology of titania being used. Standard synthesis techniques of anatase lead to a crystal that generally has 94% of the titania (101) surface exposed, and the other 6% is the higher energy (001) surface. The (101) surface has 5 & 6-fold coordinated titania whereas the (001) surface only has 5-fold (under) coordinated titania. This under-coordination leads to enhanced reactivity of the (001) surface which has been demonstrated by dissassociative adsorption of water, and catalysis applications. Much theoretical work has focused on the minority (001) surface because up until recently synthesizing anatase with enhanced exposure of the (001) surface has been difficult. The initial materials for this study will be multilayer titania nanotubes (TiNTs) and nanosheets (TiNS) which have been previously characterized by my predecessor. The TiNTs and TiNS have 100% exposed (001)-like surface. Both of these materials show enhanced stability of phosphonated dye binding as compared to the current standard of anatase nanoparticles (NPs) however, due to their limited thermal stability the potential of incorporating the TiNTs and TiNSs into devices has been eliminated in this study. To overcome the device limitations I will synthesis a novel titania nanotile

  17. Feasibility study for Zaporozhye Nuclear Power Plant spent fuel dry storage facility in Ukraine. Export trade information

    SciTech Connect

    1995-12-01

    This document reports the results of a Feasibility Study sponsored by a TDA grant to Zaporozhye Nuclear Power Plant (ZNPP) in Ukraine to study the construction of storage facilities for spent nuclear fuel. It provides pertinent information to U.S. companies interested in marketing spent fuel storage technology and related business to countries of the former Soviet Union or Eastern Europe.

  18. Study of the Physical and Energy Properties of Fuel Granules Based on a Thermomodified Wood Raw Material

    NASA Astrophysics Data System (ADS)

    Safin, R. R.; Khasanshin, R. R.; Timerbaeva, A. L.; Safina, A. V.

    2015-07-01

    The authors present the results of experimental studies of the basic properties of fuel granules that have been produced from wood raw material treated in different temperature regimes. The authors have established the influence of the temperature of pretreatment of the raw material on the hygroscopicity, swelling, flame-maintenance efficiency, and heat of combustion of fuel granules. A comparative analysis of the energy efficiency of torrefacted pellets and regular fuel granules has been made.

  19. Flame tube parametric studies for control of fuel bound nitrogen using rich-lean two-stage combustion

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Wolfbrandt, G.

    1980-01-01

    An experimental parametric study of rich-lean two-stage combustion in a flame tube is described and approaches for minimizing the conversion of fuel-bound nitrogen to nitrogen oxides in a premixed, homogeneous combustion system are evaluated. Air at 672 K and 0.48 MPa was premixed with fuel blends of propane, toluene, and pyridine at primary equivalence ratios ranging from 0.5 to 2.0 and secondary equivalence ratios of 0.5 to 0.7. Distillates of SRC-II, a coal syncrude, were also tested. The blended fuels were proportioned to vary fuel hydrogen composition from 9.0 to 18.3 weight percent and fuel nitrogen composition from zero to 1.5 weight percent. Rich-lean combustion proved effective in reducing fuel nitrogen to NO sub x conversion; conversion rates up to 10 times lower than those normally produced by single-stage combustion were achieved. The optimum primary equivalence ratio, where the least NO sub x was produced and combustion efficiency was acceptable, shifted between 1.4 and 1.7 with changes in fuel nitrogen content and fuel hydrogen content. Increasing levels of fuel nitrogen content lowered the conversion rate, but not enough to avoid higher NO sub x emissions as fuel nitrogen increased.

  20. Study of Miller timing on exhaust emissions of a hydrotreated vegetable oil (HVO)-fueled diesel engine.

    PubMed

    Heikkilä, Juha; Happonen, Matti; Murtonen, Timo; Lehto, Kalle; Sarjovaara, Teemu; Larmi, Martti; Keskinen, Jorma; Virtanen, Annele

    2012-11-01

    The effect of intake valve closure (IVC) timing by utilizing Miller cycle and start of injection (SOI) on particulate matter (PM), particle number and nitrogen oxide (NOx) emissions was studied with a hydrotreated vegetable oil (HVO)-fueled nonroad diesel engine. HVO-fueled engine emissions, including aldehyde and polyaromatic hydrocarbon (PAH) emissions, were also compared with those emitted with fossil EN590 diesel fuel. At the engine standard settings, particle number and NOx emissions decreased at all the studied load points (50%, 75%, and 100%) when the fuel was changed from EN590 to HVO. Adjusting IVC timing enabled a substantial decrease in NOx emission and combined with SOI timing adjustment somewhat smaller decrease in both NOx and particle emissions at IVC -50 and -70 degrees CA points. The HVO fuel decreased PAH emissions mainly due to the absence of aromatics. Aldehyde emissions were lower with the HVO fuel with medium (50%) load. At higher loads (75% and 100%), aldehyde emissions were slightly higher with the HVO fuel. However, the aldehyde emission levels were quite low, so no clear conclusions on the effect of fuel can be made. Overall, the study indicates that paraffinic HVO fuels are suitable for emission reduction with valve and injection timing adjustment and thus provide possibilities for engine manufacturers to meet the strictening emission limits.

  1. Physical and chemical comparison of soot in hydrocarbon and biodiesel fuel diffusion flames: A study of model and commercial fuels

    SciTech Connect

    Matti Maricq, M.

    2011-01-15

    Data are presented to compare soot formation in both surrogate and practical fatty acid methyl ester biodiesel and petroleum fuel diffusion flames. The approach here uses differential mobility analysis to follow the size distributions and electrical charge of soot particles as they evolve in the flame, and laser ablation particle mass spectrometry to elucidate their composition. Qualitatively, these soot properties exhibit a remarkably similar development along the flames. The size distributions begin as a single mode of precursor nanoparticles, evolve through a bimodal phase marking the onset of aggregate formation, and end in a self preserving mode of fractal-like particles. Both biodiesel and hydrocarbon fuels yield a common soot composition dominated by C{sub x}H{sub y}{sup +} ions, stabilomer PAHs, and fullerenes in the positive ion mass spectrum, and C{sub x}{sup -} and C{sub 2x}H{sup -} in the negative ion spectrum. These ion intensities initially grow with height in the diffusion flames, but then decline during later stages, consistent with soot carbonization. There are important quantitative differences between fuels. The surrogate biodiesel fuel methyl butanoate substantially reduces soot levels, but soot formation and evolution in this flame are delayed relative to both soy and petroleum fuels. In contrast, soots from soy and hexadecane flames exhibit nearly quantitative agreement in their size distribution and composition profiles with height, suggesting similar soot precursor chemistry. (author)

  2. Feasibility study: utilization of landfill gas for a vehicle fuel system, Rossman's landfill, Clackamas County, Oregon

    SciTech Connect

    1981-01-01

    In 1978, a landfill operator in Oregon became interested in the technical and economic feasibility of recovering the methane generated in the landfill for the refueling of vehicles. DOE awarded a grant for a site-specific feasibility study of this concept. This study investigated the expected methane yield and the development of a conceptual gas-gathering system; gas processing, compressing, and storage systems; and methane-fueled vehicle systems. Cost estimates were made for each area of study. The results of the study are presented. Reasoning that gasoline prices will continue to rise and that approximately 18,000 vehicles in the US have been converted to operate on methane, a project is proposed to use this landfill as a demonstration site to produce and process methane and to fuel a fleet (50 to 400) vehicles with the gas produced in order to obtain performance and economic data on the systems used from gas collection through vehicle operation. (LCL)

  3. Neutronics and Depletion Methods for Parametric Studies of Fluoride Salt Cooled High Temperature Reactors with Slab Fuel Geometry and Multi-Batch Fuel Management Schemes

    SciTech Connect

    Cisneros, Anselmo T.; Ilas, Dan

    2013-01-01

    The Advanced High-Temperature Reactor (AHTR) is a 3400 MWth fluoride-salt-cooled high-temperature reactor (FHR) that uses TRISO particle fuel compacted into slabs rather than spherical or cylindrical fuel compacts. Simplified methods are required for parametric design studies such that analyzing the entire feasible design space for an AHTR is tractable. These simplifications include fuel homogenization techniques to increase the speed of neutron transport calculations in depletion analysis and equilibrium depletion analysis methods to analyze systems with multi-batch fuel management schemes. This paper presents three elements of significant novelty. First, the Reactivity-Equivalent Physical Transformation (RPT) methodology usually applied in systems with coated-particle fuel in cylindrical and spherical geometries has been extended to slab geometries. Secondly, based on this newly developed RPT method for slab geometries, a methodology that uses Monte Carlo depletion approaches was further developed to search for the maximum discharge burnup in a multi-batch system by iteratively estimating the beginning of equilibrium cycle (BOEC) composition and sampling different discharge burnups. This Iterative Equilibrium Depletion Search (IEDS) method fully defines an equilibrium fuel cycle (keff, power, flux, and composition evolutions) but is computationally demanding, although feasible on single-processor workstations. Finally, an analytical method, the Non-Linear Reactivity Model, was developed by expanding the linear reactivity model to include an arbitrary number of higher order terms so that single-batch depletion results could be extrapolated to estimate the maximum discharge burnup and BOEC keff in systems with multi-batch fuel management schemes. Results from this method were benchmarked against equilibrium depletion analysis results using the IEDS.

  4. Study on Gaseous Effluent Treatment for Dissolution Step of Spent Nuclear Fuel Reprocessing

    SciTech Connect

    Mineo, H.; Iizuka, M.; Fujisaki, S.; Hotoku, S.; Asakura, T.; Uchiyama, G.

    2002-02-27

    Behavior of radioiodine and carbon-14 during spent fuel dissolution was studied in a bench-scale reprocessing test rig where 29 and 44 GWdt-1 spent fuels were respectively dissolved. Decontamination factor of AGS (silica-gel impregnated with silver nitrate) column for iodine-129 removal was measured to be more than 36,000. The measurement of iodine-129 profile in the adsorption column showed that the nuclide was effectively trapped by the adsorbent. Measurement of iodine-129 in the dissolver solution after the iodine-stripping operation using NO2 gas at 363 K, revealed that less than 0.57% of total iodine-129 generated, which was estimated by ORIGEN II calculation, was remained in the dissolver solution. Also, measurement of iodine-129 by an iodine-stripping operation from the dissolver solution using potassium iodate showed that another 2.72% of total iodine-129 precipitated as iodide. In addition, about 70 % of total iodine generated was measured in the AGS columns. Rest of iodine-129 was supposed to adsorb to a HEPA filter and the inner surface of dissolver off-gas lines. Those results on iodine-129 distribution were found to be almost identical to the results obtained in the study using iodine-131 as tracer and the results reported by other works. It was demonstrated that the two-steps iodine-stripping method using potassium iodate could expel additional iodine from the solution, more effectively than iodine-stripping operation using NO2 gas. Iodine-131 was also detected on the AGS columns at the spent fuel dissolution. Increasing burnup showed larger amount of iodine-131 since amount of curium-244 contained in the spent fuel increased with the burnup. Release of carbon-14 as carbon dioxide during dissolution was found to occur when the release of krypton-85. From the 14CO2 measurement, initial nitrogen-14 concentration in the fuel was estimated to be about several ppm, which was within the range reported.

  5. Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

    SciTech Connect

    Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio; Davila, Jesus

    2015-07-23

    During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e’n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides {sup 232}Th, {sup 238}U and {sup 237}Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

  6. Design study of Thorium-232 and Protactinium-231 based fuel for long life BWR

    SciTech Connect

    Trianti, N.; Su'ud, Z.; Riyana, E. S.

    2012-06-06

    A preliminary design study for the utilization of thorium added with {sup 231}Pa based fuel on BWR type reactor has been performed. In the previous research utilization of fuel based Thorium-232 and Uranium-233 show 10 years operation time with maximum excess-reactivity about 4.075% dk/k. To increase reactor operation time and reduce excess-reactivity below 1% dk/k, Protactinium (Pa-231) is used as Burnable Poison. Protactinium-231 has very interesting neutronic properties, which enable the core to reduce initial excess-reactivity and simultaneously increase production of {sup 233}U to {sup 231}Pa in burn-up process. Optimizations of the content of {sup 231}Pa in the core enables the BWR core to sustain long period of operation time with reasonable burn-up reactivity swing. Based on the optimization of fuel element composition (Th and Pa) in various moderation ratio we can get reactor core with longer operation time, 20 {approx} 30 years operation without fuel shuffling or refuelling, with average power densities maximum of about 35 watt/cc, and maximum excess-reactivity 0.56% dk/k.

  7. Design study of Thorium-232 and Protactinium-231 based fuel for long life BWR

    NASA Astrophysics Data System (ADS)

    Trianti, N.; Su'ud, Z.; Riyana, E. S.

    2012-06-01

    A preliminary design study for the utilization of thorium added with 231Pa based fuel on BWR type reactor has been performed. In the previous research utilization of fuel based Thorium-232 and Uranium-233 show 10 years operation time with maximum excess-reactivity about 4.075% dk/k. To increase reactor operation time and reduce excess-reactivity below 1% dk/k, Protactinium (Pa-231) is used as Burnable Poison. Protactinium-231 has very interesting neutronic properties, which enable the core to reduce initial excess-reactivity and simultaneously increase production of 233U to 231Pa in burn-up process. Optimizations of the content of 231Pa in the core enables the BWR core to sustain long period of operation time with reasonable burn-up reactivity swing. Based on the optimization of fuel element composition (Th and Pa) in various moderation ratio we can get reactor core with longer operation time, 20 ˜ 30 years operation without fuel shuffling or refuelling, with average power densities maximum of about 35 watt/cc, and maximum excess-reactivity 0.56% dk/k.

  8. Study of minimum-weight highway transporters for spent nuclear fuel casks: Technical report

    SciTech Connect

    Hoess, J.A.; Drago, V.J.

    1989-05-01

    There are federal and state limits on the maximum tractor-trailer- payload combination and individual axle loads permissible on US highways. These can generally be considered as two sets, i.e., legal-weight and overweight limits. The number of individual shipments required will decrease as the capacity of the spent nuclear fuel cask increases. Thus, there is an incentive for identifying readily available minimum-weight tractors and trailers capable of safely and reliably transporting as large a cask as possible without exceeding the legal gross combination weight (GCW) of 80,000 lb or selected overweight GCW limit of 110,000 lb. This study identifies options for commercially available heavy-duty on-highway tractors and trailers for transporting proposed future loaded spent nuclear fuel casks. Loaded cask weights of 56,000 and 80,000 lb were selected as reference design points for the legal-weight and overweight transporters, respectively. The technical data on tractor and trailer characteristics obtained indicate that it is possible to develop a tractor-trailer combination, tailored for spent nuclear fuel transportation service, utilizing existing technology and commercially available components, capable of safely and reliably transporting 56,000 and 80,000-lb spent nuclear fuel casks without exceeding GCWs of 80,000 and 10,000 lb, respectively. 4 figs., 14 tabs.

  9. Feasibility study of utilization of degummed soybean oil as a substitute for diesel fuel. Final report

    SciTech Connect

    Not Available

    1981-11-01

    The purpose of this project was to determine the economic and technological feasibility of producing a diesel oil substitute or extender from soybean oil. Existing technology was reviewed, to determine the minimum modification necessary for production of an acceptable fuel product. Current methods of oil extraction and refining were considered, as well as the products of those processes. The information developed indicated that the degummed soybean oil produced by existing processing plants is theoretically suitable for use as a diesel fuel extender. No modification of process design or equipment is required. This situation is very favorable to early commercialization of degummed soybean oil as a diesel fuel extender during the 1980's. Moreover, a large energy gain is realized when the soybean oil is utilized as fuel. Its heat of combustion is reported as 16,920 Btu per pound, or 130,000 Btu per gallon. Production of soybean oil consumes between 3000 and 5000 Btu per pound or 23,000 and 39,000 Btu per gallon. A resource availability study disclosed that the southeastern region of the United States produces approximately 260 million bushels of soybeans per year. In the same general area, fourteen extraction plants are operating, with a combined annual capacity of approximately 200 million bushels. Thus, regional production is sufficient to support the extraction capacity. Using an average figure of 1.5 gallons of oil per bushel of soybeans gives annual regional oil production of approximately 300 million gallons.

  10. Further studies on the modulation of fossil fuel production by global temperature variations

    SciTech Connect

    Rust, B.W.; Crosby, F.J. )

    1994-01-01

    This study extends the earlier work of Rust and Kirk (1982) on the inverse modulation of global fossil fuel production by variations in Northern Hemispheric temperatures. Recent revisions and extensions of the fuel production record are incorporated and a much improved temperature record in used. The new data are consistent with the predictions of the original Rust-Kirk model which is extended to allow for time lags between variations in the temperature and the corresponding responses in fuel production. The modulation enters the new model through the convolution of a lagged averaging function with the temperature time-series. Explicit terms account for the perturbations caused by the Great Depression and World War II. The final model accounts for 99.84% of the total variance in the production record. The temperature modulation produces variations of as much as 30% in the total production. This modulation represents a feedback which is consistent with the predictions of the Gaia hypothesis for a planetary greenhouse temperature control. The new model calculates 20-y fuel production predictions for three temperature scenarios which hopefully bracket the possibilities for temperature behavior during that time.

  11. Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

    NASA Astrophysics Data System (ADS)

    Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Davila, Jesus; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio

    2015-07-01

    During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e'n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides 232Th, 238U and 237Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

  12. Experimental studies of laser-ablated zirconium carbide plasma plumes: Fuel corrosion diagnostic development

    SciTech Connect

    Wantuck, P.J.; Butt, D.P.; Sappey, A.D.

    1992-01-01

    Understanding the corrosion behavior of nuclear fuel materials, such as refractory carbides, in a high temperature hydrogen environment is critical for several proposed nuclear thermal propulsion (NTP) concepts. Monitoring the fuel corrosion products is important not only for understanding corrosion characteristics, but to assess the performance of an actual, operating nuclear propulsion system as well. In this paper, we describe an experimental study initiated to develop, test, and subsequently utilize non-intrusive, laser-based diagnostics to characterize the gaseous product species which are expected to evolve during the exposure of representative fuel samples to hydrogen. Laser ablation is used to produce high temperature, vapor plumes from solid solution, uranium-free, zirconium carbide (ZrC) forms for probing by other laser diagnostic methods; predominantly laser-induced fluorescence (LIF). We discuss the laser ablation technique, results of plume emission measurements, as well as the use of planar LIF to image both the ZrC plumes and actual NTP fuel corrosion constituents.

  13. Polar studies of the sphericity degree of V/HTR nuclear fuel particles

    SciTech Connect

    Robert-Inacio, F. . E-mail: frederique.robert@isen.fr; Boschet, C.; Charollais, F.

    2006-06-15

    Advanced nuclear power reactor designs such as (Very) High Temperature Reactors (V/HTR) employ TRISO fuel particles that typically have a sub-millimetre U-based fuel kernel coated with three isotropic ceramic layers-a layer of silicon carbide sandwiched between pyrocarbon layers of different density. Evaluation of the ceramic layer thickness and of the degree of sphericity of these typical nuclear fuel particles is required at each step of the fabrication, in order to estimate future fuel performance under irradiation conditions. This study is based on the image processing of polished cross-sections, realized near the equatorial plane. From these 2D images, some measurements are carried out, giving an estimation of the diameter values for a sample of particles at each step of the coating process. These values are then statistically extended to the third dimension in order to obtain the thickness of each layer and the degree of sphericity of each particle. A representation of diameter and layer thickness in polar coordinates enables one to identify steps for which the coating process is defective or deviating from nominal objectives.

  14. Study of component technologies for fuel cell on-site integrated energy systems

    NASA Technical Reports Server (NTRS)

    Lee, W. D.; Mathias, S.

    1980-01-01

    Heating, ventilation and air conditioning equipment are integrated with three types of fuel cells. System design and computer simulations are developed to utilize the thermal energy discharge of the fuel in the most cost effective manner. The fuel provides all of the electric needs and a loss of load probability analysis is used to ensure adequate power plant reliability. Equipment cost is estimated for each of the systems analyzed. A levelized annual cost reflecting owning and operating costs including the cost of money was used to select the most promising integrated system configurations. Cash flows are presented for the most promising 16 systems. Several systems for the 96 unit apartment complex (a retail store was also studied) were cost competitive with both gas and electric based conventional systems. Thermal storage is shown to be beneficial and the optimum absorption chiller sizing (waste heat recovery) in connection with electric chillers are developed. Battery storage was analyzed since the system is not electric grid connected. Advanced absorption chillers were analyzed as well. Recommendations covering financing, technical development, and policy issues are given to accelerate the commercialization of the fuel cell for on-site power generation in buildings.

  15. Methods of discovery and techniques to study endophytic fungi producing fuel-related hydrocarbons.

    PubMed

    Strobel, Gary A

    2014-01-17

    One promising area in the search for renewable bio-fuels is the discovery of microorganisms that produce fuel-related hydrocarbons (mycodiesel) that is in stark contrast to yeast fermentation that utilizes expensive sugars or starch to produce ethanol, which is a proven and useful source of fuel, but by no means is it ideal. Recently, a number of endophytic fungi have been isolated and described that make compounds such as mono- terpenoids, alkanes, cyclohexanes, cyclopentanes, and alkyl alcohols/ketones, benzenes and polyaromatic hydrocarbons. Many of these compounds are either identical to or are closely related to those specific classes of molecules that are found in diesel. Most importantly, these organisms make hydrocarbons while utilizing cellulosic polymers found in all plant-based agricultural wastes. Also discussed are some novel methods and techniques to quantitatively and qualitatively study hydrocarbon production by these microbes. Two models are discussed for identifying potential fuel-related compounds, scaling up production of them and advanced engine testing. Finally, it seems possible that endophytic fungi may have an additional attribute of having contributed to the formation of crude oil in the first place and a description of the paleobiosphere, to test this hypothesis, is in this review.

  16. Recent studies related to head-end fuel processing at the Hanford PUREX plant

    SciTech Connect

    Swanson, J.L.

    1988-08-01

    This report presents the results of studies addressing several problems in the head-end processing (decladding, metathesis, and core dissolution) of N Reactor fuel elements in the Hanford PUREX plant. These studies were conducted over 2 years: FY 1986 and FY 1987. The studies were divided into three major areas: 1) differences in head-end behavior of fuels having different histories, 2) suppression of /sup 106/Ru volatilization when the ammonia scrubber solution resulting from decladding is decontaminated by distillation prior to being discharged, and 3) suitability of flocculating agents for lowering the amount of transuranic (TRU) element-containing solids that accompany the decladding solution to waste. 16 refs., 43 figs.

  17. Experimental and theoretical study of a dual-layer gas diffusion layer in PEM fuel cells

    NASA Astrophysics Data System (ADS)

    Park, Sehkyu

    2008-07-01

    The gas diffusion layer (GDL) in proton exchange membrane fuel cells (PEMFCs) functions as a diffuser and a current collector. The GDL typically consists of the microporous layer (MPL) and the macroporous substrate (MPS). The MPL reduces the ohmic losses and facilitates water removal in the MEA. In this study, a novel method was developed to prepare a dual-layer GDL that enhances the catalyst utilization and the overall fuel cell performance. Several characterization techniques, including mercury porosimetry, water permeation measurement, electrochemical polarization and ac impedance spectroscopy were performed to investigate how carbon loading (or MPL thickness) and PTFE content in the MPL and in the MPS control the water management in PEM fuel cells. An experimental study on carbon loading in the MPL showed that a relatively low carbon loading (0.5 mg cm-2 in this study) results in a balancing of water saturations in the catalyst layer and the GDL, thus improving the oxygen diffusion kinetics. Experimental studies on PTFE content in the MPL and in the MPS indicated that effective water management is attributed to the trade-off between the pore volume and the hydrophobic property of each diffusion layer. A theoretical study of a dual-layer GDL in PEM fuel cells demonstrated that saturation in the MPS is intimately coupled with both the fraction of hydrophilic surface and the average pore diameter. A thin and more hydrophobic MPL altered the pore geometry and the hydrophobic property of a MPS, resulting in better mass transport of reactants and products in the MEA.

  18. Hydrocarbon fuel effects in solid-oxide fuel cell operation: an experimental and modeling study of n-hexane pyrolysis.

    PubMed

    Randolph, Katie L; Dean, Anthony M

    2007-08-21

    Pyrolysis experiments of n-hexane were performed and the product distribution and fuel consumption were measured as a function of temperature. The experimental temperatures ranged from 550-675 degrees C, with a pressure of approximately 1 atm, and residence times of approximately 5 s. N-Hexane was used as a model compound to represent the linear alkanes that might be found in practical hydrocarbon fuels. Under these conditions, high fuel conversion was observed at the higher temperatures and a wide range of products were formed. The experimental observations were compared to predictions from a plug-flow model using a reaction mechanism consisting of 205 species and 1403 reactions. The hydrogen abstraction and isomerization rate coefficients in this model were based on CBS-QB3 calculations. The only model modification was adjustment of the A-factor of the initiation rates to match conversion at one temperature. This model was able to successfully predict the observed trends in both product selectivities as well as fuel conversion over the temperature range. The mechanism was also used to capture the trends previously observed in n-butane pyrolysis under similar experimental conditions. Significant differences in the sensitivity coefficients for the hexane and butane systems are discussed in terms of the competition between beta-scission and isomerization of the initial radicals formed. The kinetic model predicts that n-hexane will be completely converted within 0.1 s in the higher temperature environment ( approximately 800 degrees C) of the anode channel of a solid-oxide fuel cell (SOFC). This result clearly illustrates the need to explicitly account for gas-phase reactions in SOFC models for those cases where hydrocarbons, especially those larger than methane, are fed directly to an SOFC. PMID:17687473

  19. Topical absorption and toxicity studies of jet fuel hydrocarbons in skin

    NASA Astrophysics Data System (ADS)

    Muhammad, Faqir

    Kerosene-based fuels have been used for many decades. Over 2 million military and civilian personnel each year are occupationally exposed to various jet fuel mixtures. Dermatitis is one of the major health concerns associated with these exposures. In the past, separate absorption and toxicity studies have been conducted to find the etiology of such skin disorders. There was a need for integrated absorption and toxicity studies to define the causative constituents of jet fuel responsible for skin irritation. The focus of this thesis was to study the percutaneous absorption and to identify the hydrocarbons (HC) causing irritation in jet fuels so that preventive measures could be taken in the future. The initial study was conducted to understand the possible mechanism for additive interactions on hydrocarbon absorption/disposition in silastic, porcine skin and isolated perfused porcine skin flap (IPPSF) models. The influence of JP-8 (100) additives (MDA, BHT, 8Q405) on the dermal kinetics of 14C-naphthalene and 14C/3H-dodecane as markers of HC absorption was evaluated. This study indicated that individual and combination of additives influenced marker disposition in different membranes. MDA was a significant suppressor while BHT was a significant enhancer of naphthalene absorption in IPPSF. The 8Q405 significantly reduced naphthalene content in dosed silastic and skin indicating a direct interaction between additive and marker HC. Similarly, the individual MDA and BHT significantly retained naphthalene in the stratum corneum of porcine skin, but the combination of both of these additives statistically decreased the marker retention in the stratum corneum suggesting a potential biological interaction. This study concluded that all components of a chemical mixture should be assessed since the effects of single components administered alone or as pairs may be confounded when all are present in the complete mixture. However, this study indicated that the marker HC

  20. Study on Equilibrium Characteristics of Thorium-Plutonium-Minor Actinides Mixed Oxides Fuel in PWR

    SciTech Connect

    Waris, A.; Permana, S.; Kurniadi, R.; Su'ud, Z.; Sekimoto, H.

    2010-06-22

    A study on characteristics of thorium-plutonium-minor actinides utilization in the pressurized water reactor (PWR) with the equilibrium burnup model has been conducted. For a comprehensive evaluation, several fuel cycles scenario have been included in the present study with the variation of moderator-to-fuel volume ratio (MFR) of PWR core design. The results obviously exhibit that the neutron spectra grow to be harder with decreasing of the MFR. Moreover, the neutron spectra also turn into harder with the rising number of confined heavy nuclides. The required {sup 233}U concentration for criticality of reactor augments with the increasing of MFR for all heavy nuclides confinement and thorium and uranium confinement in PWR.

  1. Bus industry market study. Report -- Task 3.2: Fuel cell/battery powered bus system

    SciTech Connect

    Zalbowitz, M.

    1992-06-02

    In support of the commercialization of fuel cells for transportation, Georgetown University, as a part of the DOE/DOT Fuel Cell Transit Bus Program, conducted a market study to determine the inventory of passenger buses in service as of December, 1991, the number of buses delivered in 1991 and an estimate of the number of buses to be delivered in 1992. Short term and long term market projections of deliveries were also made. Data was collected according to type of bus and the field was divided into the following categories which are defined in the report: transit buses, school buses, commercial non-transit buses, and intercity buses. The findings of this study presented with various tables of data collected from identified sources as well as narrative analysis based upon interviews conducted during the survey.

  2. Improving fossil fuel emissions scenarios with urban ecosystem studies: A case study in the Salt Lake-Ogden metropolitan region

    NASA Astrophysics Data System (ADS)

    Pataki, D. E.; Dudley-Murphy, E. A.; Emmi, P. C.; Forster, C. B.; Mills, J. I.; Pardyjak, E. R.; Peterson, T. R.

    2005-05-01

    Scenarios of the future trajectory of fossil fuel emissions have been generated at the global scale using assumptions about regional to global economic growth and demography. A limitation to this approach is the mismatch in scale between local geographical, cultural, and economic factors that influence patterns of energy and fuel use and their impact on global emissions. However, resolving mismatches between local and global processes has been successfully addressed in other aspects of carbon cycle science, such as natural sources and sinks of carbon in terrestrial ecosystems. We propose a similar approach for reducing uncertainty in fossil fuel emissions scenarios with process-level studies of the factors underlying emissions at the local scale. We initiated a project to apply a whole ecosystem framework to the study of CO2 emissions in a rapidly urbanizing region in the United States. Our goal was to quantify both biophysical and socioeconomic aspects of urban ecosystem function that determined net CO2 emissions from the major sectors in the Salt Lake-Ogden metropolitan region, an area characterized by good historical records, a highly seasonal climate, and a rapid rate of both population growth and urban expansion. We analyzed the strong linkages between energy use and climate in the region with data from the local utilities. We also applied a linked land use- transportation framework that quantified interactions between urban development and emissions from the transportation sector. These processes were captured in a systems dynamics model of urban ecosystem function that incorporated stakeholder involvement in model development using a mediated modeling approach. The model was validated with direct measurements of CO2 fluxes by eddy covariance and attribution of local CO2 concentrations to fuel types using stable isotopes. The model may be used to evaluate possible consequences of policy levers such as changes in urban developmental densities, acceleration of

  3. Improving fossil fuel emissions scenarios with urban ecosystem studies: A case study in the Salt Lake-Ogden metropolitan region

    NASA Astrophysics Data System (ADS)

    Pataki, D. E.; Dudley-Murphy, E. A.; Emmi, P. C.; Forster, C. B.; Mills, J. I.; Pardyjak, E. R.; Peterson, T. R.

    2006-12-01

    Scenarios of the future trajectory of fossil fuel emissions have been generated at the global scale using assumptions about regional to global economic growth and demography. A limitation to this approach is the mismatch in scale between local geographical, cultural, and economic factors that influence patterns of energy and fuel use and their impact on global emissions. However, resolving mismatches between local and global processes has been successfully addressed in other aspects of carbon cycle science, such as natural sources and sinks of carbon in terrestrial ecosystems. We propose a similar approach for reducing uncertainty in fossil fuel emissions scenarios with process-level studies of the factors underlying emissions at the local scale. We initiated a project to apply a whole ecosystem framework to the study of CO2 emissions in a rapidly urbanizing region in the United States. Our goal was to quantify both biophysical and socioeconomic aspects of urban ecosystem function that determined net CO2 emissions from the major sectors in the Salt Lake-Ogden metropolitan region, an area characterized by good historical records, a highly seasonal climate, and a rapid rate of both population growth and urban expansion. We analyzed the strong linkages between energy use and climate in the region with data from the local utilities. We also applied a linked land use- transportation framework that quantified interactions between urban development and emissions from the transportation sector. These processes were captured in a systems dynamics model of urban ecosystem function that incorporated stakeholder involvement in model development using a mediated modeling approach. The model was validated with direct measurements of CO2 fluxes by eddy covariance and attribution of local CO2 concentrations to fuel types using stable isotopes. The model may be used to evaluate possible consequences of policy levers such as changes in urban developmental densities, acceleration of

  4. Carbon stable-isotope tracking in breath for comparative studies of fuel use.

    PubMed

    Welch, Kenneth C; Péronnet, François; Hatch, Kent A; Voigt, Christian C; McCue, Marshall D

    2016-02-01

    Almost half a century ago, researchers demonstrated that the ratio of stable carbon isotopes in exhaled breath of rats and humans could reveal the oxidation of labeled substrates in vivo, opening a new chapter in the study of fuel use, the fate of ingested substrates, and aerobic metabolism. Until recently, the combined use of respirometry and stable-isotope tracer techniques had not been broadly employed to study fuel use in other animal groups. In this review, we summarize the history of this approach in human and animal research and define best practices that maximize its utility. We also summarize several case studies that use stable-isotope measurements of breath to explore the limits of aerobic metabolism and substrate turnover among several species and various physiological states. We highlight the importance of a comparative approach in revealing the profound effects that phylogeny, ecology, and behavior can have in shaping aerobic metabolism and energetics as well as the fundamental biological principles that underlie fuel use and metabolic function across taxa. New analytical equipment and refinement of methodology make the combined use of respirometry and stable-isotope tracer techniques simpler to perform, less costly, and more field ready than ever before.

  5. EXAFS: New tool for study of battery and fuel cell materials

    NASA Technical Reports Server (NTRS)

    Mcbreen, James; Ogrady, William E.; Pandya, Kaumudi I.

    1987-01-01

    Extended X ray absorption fine structure (EXAFS) is a powerful technique for probing the local atomic structure of battery and fuel cell materials. The major advantages of EXAFS are that both the probe and the signal are X rays and the technique is element selective and applicable to all states of matter. This permits in situ studies of electrodes and determination of the structure of single components in composite electrodes, or even complete cells. EXAFS specifically probes short range order and yields coordination numbers, bond distances, and chemical identity of nearest neighbors. Thus, it is ideal for structural studies of ions in solution and the poorly crystallized materials that are often the active materials or catalysts in batteries and fuel cells. Studies on typical battery and fuel cell components are used to describe the technique and the capability of EXAFS as a structural tool in these applications. Typical experimental and data analysis procedures are outlined. The advantages and limitations of the technique are also briefly discussed.

  6. Feasibility study of a plant for LWR used fuel reprocessing by pyrochemical methods

    SciTech Connect

    Bychkov, A.V.; Kormilitsyn, M.V.; Savotchkin, Yu.P.; Sokolovsky, Yu.S.; Baganz, Catherine; Lopoukhine, Serge; Maurin, Guy; Medzadourian, Michel

    2007-07-01

    In 2005, experts from AREVA and RIAR performed a joint research work on the feasibility study of a plant reprocessing 1000 t/y of LWR spent nuclear fuel by the gas-fluoride and pyro-electrochemical techniques developed at RIAR. This work was based on the RIAR experience in development of pyrochemical processes and AREVA experience in designing UNF reprocessing plants. UNF reprocessing pyrochemical processes have been developed at RIAR at laboratory scale and technology for granulated MOX fuel fabrication and manufacturing of vibro-packed fuel rods is developed at pilot scale. The research work resulted in a preliminary feasibility assessment of the reprocessing plant according to the norms and standards applied in France. The study results interpretation must integrate the fact that the different technology steps are at very different stage of development. It appears clearly however that in its present state of development, pyro-electrochemical technology is not adapted to the treatment of an important material flow issuing from thermal reactors. There is probably an economic optimum to be studied for the choice of hydrometallurgical or pyro-electrochemical technology, depending on the area of application. This work is an example of successful and fruitful collaboration between French and Russian specialists. (authors)

  7. Results of studies on application of CCMHD to advanced fossil fuel power plant cycles

    SciTech Connect

    Foote, J.P.; Wu, Y.C.L.S.; Lineberry, J.T.

    1998-07-01

    A study was conducted to assess the potential for application of a Closed Cycle MHD disk generator (CCMHD) in advanced fossil fuel power generation systems. Cycle analyses were conducted for a variety of candidate power cycles, including simple cycle CCMHD (MHD); a cycle combining CCMHD and gas turbines (MHD/GT); and a triple combined cycle including CCMHD, gas turbines, and steam turbines (MHD/GT/ST). The above cycles were previously considered in cycle studies reported by Japanese researchers. Also considered was a CCMHD cycle incorporating thermochemical heat recovery through reforming of the fuel stream (MHD/REF), which is the first consideration of this approach. A gas turbine/steam turbine combined cycle (GT/ST) was also analyzed for baseline comparison. The only fuel considered in the study was CH4. Component heat and pressure losses were neglected, and the potential for NOx emission due to high combustion temperatures was not considered. Likewise, engineering limitations for cycle components, particularly the high temperature argon heater, were not considered. This approach was adopted to simplify the analysis for preliminary screening of candidate cycles. Cycle calculations were performed using in-house code. Ideal gas thermodynamic properties were calculated using the NASA SP- 273 data base, and thermodynamic properties for steam were calculated using the computerized ASME Steam Tables. High temperature equilibrium compositions for combustion gas were calculated using tabulated values of the equilibrium constants for the important reactions.

  8. A carbon-13 and proton nuclear magnetic resonance study of some experimental referee broadened-specification /ERBS/ turbine fuels

    NASA Technical Reports Server (NTRS)

    Dalling, D. K.; Pugmire, R. J.

    1982-01-01

    Preliminary results of a nuclear magnetic resonance (NMR) spectroscopy study of alternative jet fuels are presented. A referee broadened-specification (ERBS) aviation turbine fuel, a mixture of 65 percent traditional kerosene with 35 percent hydrotreated catalytic gas oil (HCGO) containing 12.8 percent hydrogen, and fuels of lower hydrogen content created by blending the latter with a mixture of HCGO and xylene bottoms were studied. The various samples were examined by carbon-13 and proton NMR at high field strength, and the resulting spectra are shown. In the proton spectrum of the 12.8 percent hydrogen fuel, no prominent single species is seen while for the blending stock, many individual lines are apparent. The ERBS fuels were fractionated by high-performance liquid chromatography and the resulting fractions analyzed by NMR. The species found are identified.

  9. Design study and comparative evaluation of JSFR failed fuel detection system

    SciTech Connect

    Aizawa, K.; Chikazawa, Y.; Ishikawa, N.; Kubo, S.; Okazaki, H.; Mito, M.; Tozawa, K.; Hayashi, M.

    2012-07-01

    A conceptual design study of an advanced sodium-cooled fast reactor JSFR has progressed in the 'Fast Reactor Cycle Technology Development (FaCT) 'project in Japan. JSFR has two failed fuel detection systems in the core. One is a failed fuel detection (FFD) system which continuously monitors a fission product from failed fuel subassembly. The other is a failed fuel detection and location (FFDL) system which locates when it receives signals from FFD. The FFD system consists of a FFD-DN which detects delayed neutron (DN) in sodium and a FFD-CG which detects fission products in the cover gas of the reactor vessel. In this study, requirements to the FFD-DN and the FFD-DN design to meet the requirements were investigated for the commercial and demonstration JSFR. In the commercial JSFR, a sampling type FFD which collects sodium from the reactor vessel by sampling lines for DN detectors was adopted. The performances have been investigated and confirmed by a fluid analysis in the reactor upper plenum. In the demonstration JSFR, the performance of DN detectors installed on the primary cold-leg piping has been confirmed. For the FFDL systems, experiences in the previous fast reactors and the R and D of FFDL system for JSFR were investigated. This study focuses on the Selector-Valve and the Tagging-Gas FFDL systems. Operation experiences of the Selector-valve FFDL system were accumulated in PFR and Phenix. Tagging-gas system experiences were accumulated in EBR-II and FFTF. The feasibility of both FFDL systems for JSFR was evaluated. (authors)

  10. A combinatorial study on catalytic synergism in supported metal catalysts for fuel cell technology

    NASA Astrophysics Data System (ADS)

    Kobayashi, Tetsuhiko; Ueda, Atsushi; Yamada, Yusuke; Shioyama, Hiroshi

    2004-02-01

    In order to accelerate the catalyst development for the increasing demand on the fuel cell technology, it has been attempted to adopt a combinatorial approach. The catalytic synergism, often observed on the supported metal catalysts for the fuel cell utilization, has been subjected to study. It is proposed herein that not only a comparison of catalysts in one reaction, but also the comparison of interrelated reactions by use of a common catalyst library brings about important information to elucidate the catalytic synergism. Preliminary results of the comparison between the water-gas shift reaction and the steam reforming of MeOH on a given set of catalyst library are presented. An important indicator to predict the serendipitous synergism is expected to be obtained from such information by use of artificial intelligence.

  11. Toxicity evaluation of 2-hydroxybiphenyl and other compounds involved in studies of fossil fuels biodesulphurisation.

    PubMed

    Alves, L; Paixão, S M

    2011-10-01

    The acute toxicity of some compounds used in fossil fuels biodesulphurisation studies, on the respiration activity, was evaluated by Gordonia alkanivorans and Rhodococcus erythropolis. Moreover, the effect of 2-hydroxybiphenyl on cell growth of both strains was also determined, using batch (chronic bioassays) and continuous cultures. The IC₅₀ values obtained showed the toxicity of all the compounds tested to both strains, specially the high toxicity of 2-HBP. These results were confirmed by the chronic toxicity data. The toxicity data sets highlight for a higher sensitivity to the toxicant by the strain presenting a lower growth rate, due to a lower cells number in contact with the toxicant. Thus, microorganisms exhibiting faster generation times could be more resistant to 2-HBP accumulation during a BDS process. The physiological response of both strains to 2-HBP pulse in a steady-state continuous culture shows their potential to be used in a future fossil fuel BDS process.

  12. Experimental Study of the Combustion Dynamics of Renewable & Fossil Fuel Co-Fire in Swirling Flame

    NASA Astrophysics Data System (ADS)

    Zaķe, M.; Barmina, I.; Kriško, V.; Gedrovičs, M.; Descņickis, A.

    2009-01-01

    The complex experimental research into the combustion dynamics of rene-wable (wood biomass) and fossil (propane) fuel co-fire in a swirling flame flow has been carried out with the aim to achieve clean and effective heat production with reduced carbon emissions. The effect of propane co-fire on the formation of the swirling flame velocity, temperature and composition fields as well as on the combustion efficiency and heat output has been analysed. The results of experimental study show that the propane supply into the wood biomass gasifier provides faster wood fuel gasification with active release of volatiles at the primary stage of swirling flame flow formation, while the swirl-induced recirculation with enhanced mixing of the flame components results in a more complete burnout of wood volatiles downstream of the combustor with reduced mass fraction of polluting impurities in the emissions.

  13. Conceptual design study of small long-life PWR based on thorium cycle fuel

    NASA Astrophysics Data System (ADS)

    Subkhi, M. Nurul; Su'ud, Zaki; Waris, Abdul; Permana, Sidik

    2014-09-01

    A neutronic performance of small long-life Pressurized Water Reactor (PWR) using thorium cycle based fuel has been investigated. Thorium cycle which has higer conversion ratio in thermal region compared to uranium cycle produce some significant of 233U during burn up time. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.3, while the multi-energy-group diffusion calculations were optimized in whole core cylindrical two-dimension R-Z geometry by SRAC-CITATION. this study would be introduced thorium nitride fuel system which ZIRLO is the cladding material. The optimization of 350 MWt small long life PWR result small excess reactivity and reduced power peaking during its operation.

  14. Conceptual design study of small long-life PWR based on thorium cycle fuel

    SciTech Connect

    Subkhi, M. Nurul; Su'ud, Zaki; Waris, Abdul; Permana, Sidik

    2014-09-30

    A neutronic performance of small long-life Pressurized Water Reactor (PWR) using thorium cycle based fuel has been investigated. Thorium cycle which has higher conversion ratio in thermal region compared to uranium cycle produce some significant of {sup 233}U during burn up time. The cell-burn up calculations were performed by PIJ SRAC code using nuclear data library based on JENDL 3.3, while the multi-energy-group diffusion calculations were optimized in whole core cylindrical two-dimension R-Z geometry by SRAC-CITATION. this study would be introduced thorium nitride fuel system which ZIRLO is the cladding material. The optimization of 350 MWt small long life PWR result small excess reactivity and reduced power peaking during its operation.

  15. Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Yang, Y.; Xu, H.

    2011-10-01

    This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

  16. The study of material accountancy procedures for uranium in a whole nuclear fuel cycle

    SciTech Connect

    Nakano, Hiromasa; Akiba, Mitsunori

    1995-07-01

    Material accountancy procedures for uranium under a whole nuclear fuel cycle were studied by taking into consideration the material accountancy capability associated with realistic measurement uncertainties. The significant quantity used by the International Atomic Energy Agency (IAEA) for low-enriched uranium is 75 kg U-235 contained. A loss of U-235 contained in uranium can be detected by either of the following two procedures: one is a traditional U-235 isotope balance, and the other is a total uranium element balance. Facility types studied in this paper were UF6 conversion, gas centrifuge uranium enrichment, fuel fabrication, reprocessing, plutonium conversion, and MOX fuel production in Japan, where recycled uranium is processed in addition to natural uranium. It was found that the material accountancy capability of a total uranium element balance was almost always higher than that of a U-235 isotope balance under normal accuracy of weight, concentration, and enrichment measurements. Changing from the traditional U-235 isotope balance to the total uranium element balance for these facilities would lead to a gain of U-235 loss detection capability through material accountancy and to a reduction in the required resources of both the IAEA and operators.

  17. Morphology studies on high-temperature polymer electrolyte membrane fuel cell electrodes

    NASA Astrophysics Data System (ADS)

    Mack, Florian; Klages, Merle; Scholta, Joachim; Jörissen, Ludwig; Morawietz, Tobias; Hiesgen, Renate; Kramer, Dominik; Zeis, Roswitha

    2014-06-01

    The electrode morphology influences the properties and performance of polymer electrolyte membrane fuel cells (PEMFC). Here we report our studies of two different electrodes for high-temperature PEMFC prepared by spraying and coating and their impact on the fuel cell performance. Differences in 3D microstructure and adhesion between catalyst layer and gas diffusion layer (GDL) of the electrodes were studied with X-ray microtomography. Scanning electrode microscope investigations show hairline cracks between agglomerates on the surface of the sprayed electrode, whereas the coated electrode shows a network of shrinkage cracks in the catalyst layer. The distribution of the electrode binder polytetrafluoroethylene (PTFE) is related to the locally resolved conductivity, which was determined by scanning the electrode surfaces with a conductive atomic force microscopy (AFM) tip. The macrostructures of the sprayed and coated electrodes are different but contain similar pore structures. The coated electrode has a higher PTFE concentration on the top region, which tends to form a nonconductive and less wettable "skin" on the electrode surface and delays the start-up of the fuel cell. In contrast to low-temperature PEMFC, the electrode morphology has only a minor impact on the steady-state cell performance of high-temperature PEMFC.

  18. Thermal performance sensitivity studies in support of material modeling for extended storage of used nuclear fuel

    SciTech Connect

    Cuta, Judith M.; Suffield, Sarah R.; Fort, James A.; Adkins, Harold E.

    2013-08-15

    The work reported here is an investigation of the sensitivity of component temperatures of a storage system, including fuel cladding temperatures, in response to age-related changes that could degrade the design-basis thermal behavior of the system. Three specific areas of interest were identified for this study. • degradation of the canister backfill gas from pure helium to a mixture of air and helium, resulting from postulated leakage due to stress corrosion cracking (SCC) of canister welds • changes in surface emissivity of system components, resulting from corrosion or other aging mechanisms, which could cause potentially significant changes in temperatures and temperature distributions, due to the effect on thermal radiation exchange between components • changes in fuel and basket temperatures due to changes in fuel assembly position within the basket cells in the canister The purpose of these sensitivity studies is to provide a realistic example of how changes in the physical properties or configuration of the storage system components can affect temperatures and temperature distributions. The magnitudes of these sensitivities can provide guidance for identifying appropriate modeling assumptions for thermal evaluations extending long term storage out beyond 50, 100, 200, and 300 years.

  19. Conceptual studies for pressurised water reactor cores employing plutonium erbium zirconium oxide inert matrix fuel assemblies

    NASA Astrophysics Data System (ADS)

    Stanculescu, A.; Kasemeyer, U.; Paratte, J.-M.; Chawla, R.

    1999-08-01

    The most efficient way to enhance plutonium consumption in light water reactors is to eliminate the production of plutonium all together. This requirement leads to fuel concepts in which the uranium is replaced by an inert matrix. At PSI, studies have focused on employing ZrO 2 as inert matrix. Adding a burnable poison to such a fuel proves to be necessary. As a result of scoping studies, Er 2O 3 was identified as the most suitable burnable poison material. The results of whole-core three-dimensional neutronics analyses indicated, for a present-day 1000 MW e pressurised water reactor (PWR), the feasibility of an asymptotic equilibrium four-batch cycle fuelled solely with the proposed PuO 2-Er 2O 3-ZrO 2 inert matrix fuel (IMF). The present paper presents the results of more recent investigations related to `real-life' situations, which call for transition configurations in which mixed IMF and UO 2 assembly loadings must be considered. To determine the influence of the introduction of IMF assemblies on the characteristics of a UO 2-fuelled core, three-dimensional full-core calculations have been performed for a present-day 1000 MW e PWR containing up to 12 optimised IMF assemblies.

  20. Preliminary study on new configuration with LEU fuel assemblies for the Dalat nuclear research reactor

    SciTech Connect

    Van Lam Pham; Vinh Vinh Le; Ton Nghiem Huynh; Ba Vien Luong; Kien Cuong Nguyen

    2008-07-15

    The fuel conversion of the Dalat Nuclear Research Reactor (DNRR) is being realized. The DNRR is a pool type research reactor which was reconstructed from the 250 kW TRIGA- MARK II reactor. The reconstructed reactor attained its nominal power of 500 kW in February 1984. According to the results of design and safety analyses performed by the joint study between RERTR Program at Argonne National Laboratory (ANL) and Vietnam Atomic Energy Commission (VAEC) the mixed core of irradiated HEU and new LEU WWR-M2 fuel assemblies will be created soon. This paper presents the results of preliminary study on new configuration with only LEU fuel assemblies for the DNRR. The codes MCNP, REBUS and VARI3D are used to calculate neutron flux performance in irradiation positions and kinetics parameters. The idea of change of Beryllium rod reloading enables to get working configuration assured shutdown margin, thermal-hydraulic safety and increase in thermal neutron flux in neutron trap at the center of DNRR active core. (author)

  1. An analytical model and parametric study of electrical contact resistance in proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Wu, Zhiliang; Wang, Shuxin; Zhang, Lianhong; Hu, S. Jack

    This paper presents an analytical model of the electrical contact resistance between the carbon paper gas diffusion layers (GDLs) and the graphite bipolar plates (BPPs) in a proton exchange membrane (PEM) fuel cell. The model is developed based on the classical statistical contact theory for a PEM fuel cell, using the same probability distributions of the GDL structure and BPP surface profile as previously described in Wu et al. [Z. Wu, Y. Zhou, G. Lin, S. Wang, S.J. Hu, J. Power Sources 182 (2008) 265-269] and Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Results show that estimates of the contact resistance compare favorably with experimental data by Zhou et al. [Y. Zhou, G. Lin, A.J. Shih, S.J. Hu, J. Power Sources 163 (2007) 777-783]. Factors affecting the contact behavior are systematically studied using the analytical model, including the material properties of the two contact bodies and factors arising from the manufacturing processes. The transverse Young's modulus of chopped carbon fibers in the GDL and the surface profile of the BPP are found to be significant to the contact resistance. The factor study also sheds light on the manufacturing requirements of carbon fiber GDLs for a better contact performance in PEM fuel cells.

  2. Fuel quality/processing study. Volume 2: Appendix. Task 1 literature survey

    NASA Technical Reports Server (NTRS)

    Ohara, J. B.; Bela, A.; Jentz, N. E.; Klumpe, H. W.; Kessler, H. E.; Kotzot, H. T.; Loran, B. L.

    1981-01-01

    The results of a literature survey of fuel processing and fuel quality are given. Liquid synfuels produced from coal and oil shale are discussed. Gas turbine fuel property specifications are discussed. On-site fuel pretreatment and emissions from stationary gas turbines are discussed. Numerous data tables and abstracts are given.

  3. Impact study on the use of biomass-derived fuels in gas turbines for power generation

    SciTech Connect

    Moses, C A; Bernstein, H

    1994-01-01

    This report evaluates the properties of fuels derived from biomass, both gaseous and liquid, against the fuel requirements of gas turbine systems for gernating electrical power. The report attempts to be quantitative rather than merely qualitative to establish the significant variations in the properties of biomass fuels from those of conventional fuels. Three general categories are covered: performance, durability, and storage and handling.

  4. A comparison study of ash formation during pilot-scale combustion of pulverized coal and coal-water slurry fuels

    SciTech Connect

    Miller, S.F.

    1992-01-01

    The objective of this study was to investigate the effect of fuel form. specifically pulverized coal and coal-water slurry fuel (CWSF), on the particle size distribution (PSD) and inorganic composition of the ash formed during combustion. Three areas of primary interest were fuel particle and droplet size distribution, mineral matter PSD, and the composition and occurrence of inorganics in the fuel. The reactions of pyrite, silicates, aluminosilicates, and alkali and alkaline earth elements during combustion are traced. Two coals, a West Virginia Elk Creek high volatile A bituminous coal and the North Dakota Beulah lignite, were fired as a standard utility grind pulverized fuel and a CWSF at 316.2 MJ/h at 20% excess air in the Penn State Combustion Laboratory down-fired combustor. Fuel PSD and droplet size distribution of the pulverized coal and CWSF are important in determining the PSD of the respective ash when the PSD of the mineral matter and the composition and occurrence of the inorganics in the two fuels are similar, as in the case of the Elk Creek fuels. The mechanism for ash formation in both Elk Creek fuels was coalescence and agglomeration of the inorganics in the coal. The Elk Creek CWSF ash was coarser than the pulverized coal ash due to the larger CWSF char size formed during atomization. The average diameter of the inorganic particles identified in the pulverized coal ash was 2.6 times smaller than those identified in the fuel. The mechanism for ash formation in the Beulah CWSF was coalescence and agglomeration of inherent mineral matter. The average diameter of the inorganic particles identified in the CWSF ash was 3.3 times larger than those identified in the fuel.

  5. The study on injection parameters of selected alternative fuels used in diesel engines

    NASA Astrophysics Data System (ADS)

    Balawender, K.; Kuszewski, H.; Lejda, K.; Lew, K.

    2016-09-01

    The paper presents selected results concerning fuel charging and spraying process for selected alternative fuels, including regular diesel fuel, rape oil, FAME, blends of these fuels in various proportions, and blends of rape oil with diesel fuel. Examination of the process included the fuel charge measurements. To this end, a set-up for examination of Common Rail-type injection systems was used constructed on the basis of Bosch EPS-815 test bench, from which the high-pressure pump drive system was adopted. For tests concerning the spraying process, a visualisation chamber with constant volume was utilised. The fuel spray development was registered with the use of VisioScope (AVL).

  6. Alternative diesel fuel study on four different types of vegetable oils of Turkish origin

    SciTech Connect

    Oezaktas, T.; Cigizoglu, K.B.; Karaosmanoglu, F.

    1997-02-01

    Four different types of vegetable oils of Turkish origin (sunflower, corn, soybean, and olive oil) were blended with grade 2-D diesel fuel at a ratio of 20/80 (v/v). Blends were investigated in a diesel engine with a precombustion chamber at speeds between 1,200 and 2,100 rpm. Vegetable oils, diesel fuel, and fuel blends were characterized according to standard test methods. It was found that for short-term use, the fuel blends have engine characteristics similar to the baseline diesel fuel. Fuel blends also display less smoke emissions than diesel fuel.

  7. Experimental plan for the fuel-oil study. Weatherization Assistance Program: Volume 2

    SciTech Connect

    Ternes, M.P.; Levins, W.P.; Brown, M.A.

    1992-01-01

    An up-to-date assessment of the Weatherization Assistance Program (WAP) is being performed by the US Department of Energy WAP Division and the Oak Ridge National Laboratory. Five studies form the evaluation. Major goals of the Fuel-Oil Study are to estimate the fuel oil saved by the WAP in the Northeast during the 1990 and 1991 program years, identify and quantify non-energy impacts of the WAP, assess the cost effectiveness of the WAP within this submarket, and assess factors which may cause savings and cost effectiveness to vary. The study will only analyze single-family houses in the nine states in the Northeast census region and will be carried out over two heating seasons (1990 and 1991 WAP program years). A split-winter, pre- and post-weatherization experimental design with a control group will be used. Houses will be monitored over one winter. Energy conservation measures will be installed in the weatherized houses in January of each winter by the local WAP subgrantee. One hundred twenty five weatherized houses and 75 control houses will be monitored over the 1990--1991 winter; a different set of 200 houses will be monitored over the 1991--1992 winter. The houses will be evenly distributed among 25 subgrantees. Space-heating fuel-oil consumption, indoor temperature, and outdoor temperature data will be collected for all houses. Fuel-oil delivery data will be collected for each house monitored over the 1990--1991 winter for at least a year before weatherization. The delivery data will be analyzed to determine if the accuracy of the study can be improved by collecting fuel-oil delivery data on a larger sample of houses over the 1991--1992 winter. Detailed survey information will be obtained on all the houses. This information includes descriptive details of the house and its mechanical systems, details on household size and other demographics, and occupant answers to questions regarding comfort, safety, and operation of their space-heating system and house.

  8. A study on emission performance of a diesel engine fueled with five typical methyl ester biodiesels

    NASA Astrophysics Data System (ADS)

    Wu, Fujia; Wang, Jianxin; Chen, Wenmiao; Shuai, Shijin

    As an alternative and renewable fuel, biodiesel can effectively reduce diesel engine emissions, especially particulate matter and dry soot. However, the biodiesel effects on emissions may vary as the source fuel changes. In this paper, the performance of five methyl esters with different sources was studied: cottonseed methyl ester (CME), soybean methyl ester (SME), rapeseed methyl ester (RME), palm oil methyl ester (PME) and waste cooking oil methyl ester (WME). Total particulate matter (PM), dry soot (DS), non-soot fraction (NSF), nitrogen oxide (NO x), unburned hydrocarbon (HC), and carbon monoxide (CO) were investigated on a Cummins ISBe6 Euro III diesel engine and compared with a baseline diesel fuel. Results show that using different methyl esters results in large PM reductions ranging from 53% to 69%, which include the DS reduction ranging from 79% to 83%. Both oxygen content and viscosity could influence the DS emission. Higher oxygen content leads to less DS at high load while lower viscosity results in less DS at low load. NSF decreases consistently as cetane number increases except for PME. The cetane number could be responsible for the large NSF difference between different methyl esters.

  9. Experimental study on tribrachial flames in narrow channels with small fuel concentration gradients

    SciTech Connect

    Cho, Sang Moon; Lee, Min Jung; Kim, Nam Il

    2010-11-15

    Edge flames have become a subject of interest as basic structures for lifted-flame stabilization and turbulent flame propagation. Recently, with the development of small diffusion flame devices as energy sources for various small mechanical systems, edge flames within narrow spaces have also been investigated. In this study, the structures and propagation characteristics of a tribrachial flame (or an edge flame) in a confined narrow channel, with very small fuel concentration gradients, were experimentally investigated. Tribrachial flames could be successfully stabilized in the narrow channels. The flame shapes and propagation velocities were compared by changing the four experimental parameters of the mean velocity, fuel concentration gradient, channel gap, and fuel dilution ratio. It was experimentally observed that the luminosity of the diffusion branch diminished when the channel gap decreased. It was also found that there is a critical condition in the channel gap for maximum propagation velocity. A flow redirection effect and a heat loss effect are thought to have played a key role in the variation of the PVTF in a narrow channel, and their competition with each other caused a peak value of the PVTF at the critical channel gap. (author)

  10. FUNDAMENTAL STUDIES OF THE DURABILITY OF MATERIALS FOR INTERCONNECTS IN SOLID OXIDE FUEL CELLS

    SciTech Connect

    Frederick S. Pettit; Gerald H. Meier

    2003-06-30

    This report describes the result of the first eight months of effort on a project directed at improving metallic interconnect materials for solid oxide fuel cells (SOFCs). The results include cyclic oxidation studies of a group of ferritic alloys, which are candidate interconnect materials. The exposures have been carried out in simulated fuel cell atmospheres. The oxidation morphologies have been characterized and the ASR has been measured for the oxide scales. The effect of fuel cell electric current density on chromia growth rates has been considered The thermomechanical behavior of the scales has been investigated by stress measurements using x-ray diffraction and interfacial fracture toughness measurements using indentation. The ultimate goal of this thrust is to use knowledge of changes in oxide thickness, stress and adhesion to develop accelerated testing methods for evaluating SOFC interconnect alloys. Finally a theoretical assessment of the potential for use of ''new'' metallic materials as interconnect materials has been conducted and is presented in this report. Alloys being considered include materials based on pure nickel, materials based on the ''Invar'' concept, and coated materials to optimize properties in both the anode and cathode gases.

  11. Study of fuel consumption and cooling system in low heat rejection turbocharged diesel engines

    SciTech Connect

    Taymaz, I.; Gur, M.; Cally, I.; Mimaroglu, A.

    1998-07-01

    In a conventional internal combustion engine, approximately one-third of total fuel input energy is converted to useful work. Since the working gas in a practical engine cycle is not exhausted at ambient temperature, a major part of the energy is lost with the exhaust gases. In addition another major part of energy input is rejected in the form of heat via the cooling system. If the energy normally rejected to the coolant could be recovered instead on the crankshaft as useful work, then a substantial improvement in fuel economy would result. At the same time, the cooling water, antifreeze, thermostat, radiator, water pump, cooling fan, and associated hoses and clamps could be eliminated. A new trend in the field of internal combustion engines is to insulate the heat transfer surfaces such as the combustion chamber, cylinder wall, cylinder head, piston and valves by ceramic insulating materials for the improvement of engine performance and elimination of cooling system. In this study, the effect of insulated heat transfer surfaces on direct injected and turbocharged diesel engine fuel consumption and cooling system were investigated. The research engine was a four-stroke, direct injected, six cylinder, turbocharged and intercooled diesel engine. This engine was tested at different speeds and loads conditions without coating. Then, combustion chamber surfaces, cylinder head, valves and piston crown faces was coated with ceramic materials. Ceramic layers were made of CaZrO{sub 3} and MgZrO{sub 3} and plasma coated onto base of the NiCrAl bond coat. The ceramic coated research engine was tested at the same operation conditions as the standard (without coating) engine. The results indicate a reduction in fuel consumption and heat losses to engine cooling system of the ceramic coated engine.

  12. Passive Tomography for Spent Fuel Verification: Analysis Framework and Instrument Design Study

    SciTech Connect

    White, Timothy A.; Svard, Staffan J.; Smith, Leon E.; Mozin, Vladimir V.; Jansson, Peter; Davour, Anna; Grape, Sophie; Trellue, H.; Deshmukh, Nikhil S.; Wittman, Richard S.; Honkamaa, Tapani; Vaccaro, Stefano; Ely, James

    2015-05-18

    The potential for gamma emission tomography (GET) to detect partial defects within a spent nuclear fuel assembly is being assessed through a collaboration of Support Programs to the International Atomic Energy Agency (IAEA). In the first phase of this study, two safeguards verification objectives have been identified. The first is the independent determination of the number of active pins that are present in the assembly, in the absence of a priori information. The second objective is to provide quantitative measures of pin-by-pin properties, e.g. activity of key isotopes or pin attributes such as cooling time and relative burnup, for the detection of anomalies and/or verification of operator-declared data. The efficacy of GET to meet these two verification objectives will be evaluated across a range of fuel types, burnups, and cooling times, and with a target interrogation time of less than 60 minutes. The evaluation of GET viability for safeguards applications is founded on a modelling and analysis framework applied to existing and emerging GET instrument designs. Monte Carlo models of different fuel types are used to produce simulated tomographer responses to large populations of “virtual” fuel assemblies. Instrument response data are processed by a variety of tomographic-reconstruction and image-processing methods, and scoring metrics specific to each of the verification objectives are defined and used to evaluate the performance of the methods. This paper will provide a description of the analysis framework and evaluation metrics, example performance-prediction results, and describe the design of a “universal” GET instrument intended to support the full range of verification scenarios envisioned by the IAEA.

  13. Growth study and hydrocarbonoclastic potential of microorganisms isolated from aviation fuel spill site in Ibeno, Nigeria.

    PubMed

    Etuk, C U; John, R C; Ekong, U E; Akpan, M M

    2012-10-01

    The growth study and hydrocarbonoclastic potential of microorganisms isolated from aviation fuel spill sites at Inua-eyet Ikot in Ibeno, Nigeria were examined using standard microbiological methods. The results of the analysis revealed that the viable plate count of microorganisms in the polluted soil ranged from 2.2 ± 0.04 × 10(3) to 3.4 ± 0.14 × 10(6) cfu/g for bacteria and 1.4 ± 0.5 × 10(2) to 2.3 ± 0.4 × 10(4) cfu/g for fungi while count of biodegraders ranged from 1.2 ± 0.4 × 10(3) to 2.1 ± 0.8 × 10(5) cfu/g. A total of 11 microbial isolates comprising of Micrococcus, Klebsiella, Flavobacterium, Bacillus, Pseudomonas, Candida, Aspergillus, Cladosporium, Penicillium, Saccharomyces and Fusarium were characterized. The ability of the selected isolates to utilize the pollutant (aviation fuel) as their sole source of carbon and energy was examined and noticed to vary in growth profiles between the isolates. The results of their degradability after 28 days of incubation shows that species of Cladosporium, Pseudomonas, Candida, Bacillus, Micrococcus and Penicillium were the most efficient Aviation fuel degraders with percentage weight loss of 86.2, 78.4, 78, 56, 53 and 50.6 respectively. Flavobacterium, Saccharomyces and Aspergillus exhibited moderate growth with percentage weight loss of 48, 45.8 and 43.4 respectively while Klebsiella and Fusarium species showed minimal growth with percentage weight loss of 20 and 18.5 respectively. The results imply that the most efficient biodegraders like Cladosporium, Pseudomonas, Candida, Bacillus and Microoccus could tolerate and remove aviation fuel from the environment.

  14. Laboratory studies of shear/leach processing of zircaloy clad metallic uranium reactor fuel

    SciTech Connect

    Swanson, J.L.; Bray, L.A.; Kjarmo, H.E.; Ryan, J.L.; Matsuzaki, C.L.; Pitman, S.G.; Haberman, J.H.

    1985-12-01

    The safety aspects addressed centered on understanding and explaining the undesirable reactions, ''fires,'' observed in a few instances during earlier processing of such fuel at the Nuclear Fuels Services (NFS) plant at West Valley, New York. Consideration of the dissolver fires that occurred at NFS leads to the conclusion that they resulted from rapid reactions with uranium metal, rather than with zirconium metal or with sensitized weld beads. The fires observed at NFS during hulls handling operations may have involved sensitized weld beads as suggested by earlier investigators, but current results suggest that these fires also could have been caused by reactions involving uranium metal. Very little pyrophoric activity was observed in leeached cladding hulls, indicating a very low probability for safety problems resulting from the U-Zr intermetallic zone in N-Reactor fuel. Consideration of the potential role of hydrides in the fires observed at NFS indicates that they were also not important factors. Consideration was also given to protective atmospheres to be used during shearing to prevent excessive reaction during that operation. A water deluge during shearing will likely provide adequate safety while meshing well with other process considerations. Studies on the dissolution of metallic uranium in nitric acid show an initial slower reaction followed by a faster reaction that proceeds at a sustained rate for a prolonged period of time. At solution concentrations typical of those encountered in practical uranium dissolver conditions, this sustained rate is governed by an equation such as: Dissolution rate = K (surface area) ((HNO3)+2(U))/sup 2.6/. Little difference was found in dissolution rates of as-fabricated and of irradiated fuel. The transuranic element content of leached cladding hulls was found to be approx. 400 nCi/g. This is too high to allow disposal as low-level waste.

  15. Pyroprocessing of Oxidized Sodium-Bonded Fast Reactor Fuel -- an Experimental Study of Treatment Options for Degraded EBR-II Fuel

    SciTech Connect

    S. D. Herrmann; L. A. Wurth; N. J. Gese

    2013-09-01

    An experimental study was conducted to assess pyrochemical treatment options for degraded EBR-II fuel. As oxidized material, the degraded fuel would need to be converted back to metal to enable electrorefining within an existing electrometallurgical treatment process. A lithium-based electrolytic reduction process was studied to assess the efficacy of converting oxide materials to metal with a particular focus on the impact of zirconium oxide and sodium oxide on this process. Bench-scale electrolytic reduction experiments were performed in LiCl-Li2O at 650 °C with combinations of manganese oxide (used as a surrogate for uranium oxide), zirconium oxide, and sodium oxide. The experimental study illustrated how zirconium oxide and sodium oxide present different challenges to a lithium-based electrolytic reduction system for conversion of select metal oxides to metal.

  16. Breeder Spent Fuel Handling (BSFH) cask study for FY83. Final report

    SciTech Connect

    Diggs, J M

    1985-01-01

    This report documents a study conducted to investigate the applicability of existing LWR casks to shipment of long-cooled LMFBR fuel from the Clinch River Breeder Reactor Plant (CRBRP) to the Breeder Reprocessing Engineering Test (BRET) Facility. This study considered a base case of physical constraints of plants and casks, handling capabilities of plants, through-put requirements, shielding requirements due to transportation regulation, and heat transfer capabilities of the cask designs. Each cask design was measured relative to the base case. 15 references, 4 figures, 6 tables.

  17. Microbeam x-ray absorption spectroscopy study of chromium in large-grain uranium dioxide fuel

    NASA Astrophysics Data System (ADS)

    Mieszczynski, C.; Kuri, G.; Bertsch, J.; Martin, M.; Borca, C. N.; Delafoy, Ch; Simoni, E.

    2014-09-01

    Synchrotron-based microprobe x-ray absorption spectroscopy (XAS) has been used to study the local atomic structure of chromium in chromia-doped uranium dioxide (UO2) grains. The specimens investigated were a commercial grade chromia-doped UO2 fresh fuel pellet, and materials from a spent fuel pellet of the same batch, irradiated with an average burnup of ~40 MW d kg-1. Uranium L3-edge and chromium K-edge XAS have been measured, and the structural environments of central uranium and chromium atoms have been elucidated. The Fourier transform of uranium L3-edge extended x-ray absorption fine structure shows two well-defined peaks of U-O and U-U bonds at average distances of 2.36 and 3.83 Å. Their coordination numbers are determined as 8 and 11, respectively. The chromium Fourier transform extended x-ray absorption fine structure of the pristine UO2 matrix shows similar structural features with the corresponding spectrum of the irradiated spent fuel, indicative of analogous chromium environments in the two samples studied. From the chromium XAS experimental data, detectable next neighbor atoms are oxygen and uranium of the cation-substituted UO2 lattice, and two distinct subshells of chromium and oxygen neighbors, possibly because of undissolved chromia particles present in the doped fuels. Curve-fitting analyses using theoretical amplitude and phase-shift functions of the closest Cr-O shell and calculations with ab initio computer code FEFF and atomic clusters generated from the chromium-dissolved UO2 structure have been carried out. There is a prominent reduction in the length of the adjacent Cr-O bond of about 0.3 Å in chromia-doped UO2 compared with the ideal U-O bond length in standard UO2 that would be expected because of the change in effective Coulomb interactions resulting from replacing U4+ with Cr3+ and their ionic size differences. The contraction of shortest Cr-U bond is ~0.1 Å relative to the U-U bond length in bulk UO2. The difference in the

  18. Fundamental Studies of Irradiation-Induced Defect Formation and Fission Product Dynamics in Oxide Fuels

    SciTech Connect

    Stubbins, James

    2012-12-19

    The objective of this research program is to address major nuclear fuels performance issues for the design and use of oxide-type fuels in the current and advanced nuclear reactor applications. Fuel performance is a major issue for extending fuel burn-up which has the added advantage of reducing the used fuel waste stream. It will also be a significant issue with respect to developing advanced fuel cycle processes where it may be possible to incorporate minor actinides in various fuel forms so that they can be 'burned' rather than join the used fuel waste stream. The potential to fission or transmute minor actinides and certain long-lived fission product isotopes would transform the high level waste storage strategy by removing the need to consider fuel storage on the millennium time scale.

  19. Fuel retention study in fusion reactor walls by micro-NRA deuterium mapping

    NASA Astrophysics Data System (ADS)

    Pelicon, P.; Vavpetič, P.; Grlj, N.; Čadež, I.; Markelj, S.; Brezinsek, S.; Kreter, A.; Dittmar, T.; Tsitrone, E.; Pégourié, B.; Languille, P.; Rubel, M.; Schwarz-Selinger, T.

    2011-10-01

    Nuclear Reaction Analysis (NRA) with a 3He ion beam is a powerful analytical technique for analysis of light elements in thin films. The main motivation for 3He focused beam applications is lateral mapping of deuterium using the nuclear reaction D(3He,p)4He in surfaces exposed to a tokamak plasma, where a lateral resolution in the μm-range provides unique information for fuel retention studies. At the microprobe at the Jožef Stefan Institute typical helium ion currents of 300 pA and beam dimensions of 4 × 4 μm2 can be obtained. This work is focused on micro-NRA studies of plasma-facing materials using a set-up consisting of a silicon partially depleted charge particle detector for NRA spectroscopy applied in parallel with a permanently installed X-ray detector, an RBS detector and a beam chopper for ion dose monitoring. A method for absolute deuterium quantification is described. In addition, plasma-deposited amorphous deuterated carbon thin films (a-C:D) with known D content were used as a reference. The method was used to study deuterium fuel retention in carbon fibre composite materials exposed to a deuterium plasma in the Tore Supra and TEXTOR tokamaks. The high lateral resolution of micro-NRA allowed us to make a detailed study of the influence of topography on the fuel retention process. We demonstrated that the surface topography plays a dominant role in the retention of deuterium. The deep surfaces inside the castellation gaps showed approximately two orders of magnitude lower deuterium concentrations than in areas close to the exposed surface.

  20. Experimental and Numerical Studies for Soot Formation in Laminar Coflow Diffusion Flames of Jet A-1 and Synthetic Jet Fuels

    NASA Astrophysics Data System (ADS)

    Saffaripour, Meghdad

    In the present doctoral thesis, fundamental experimental and numerical studies are conducted for the laminar, atmospheric pressure, sooting, coflow diffusion flames of Jet A-1 and synthetic jet fuels. The first part of this thesis presents a comparative experimental study for Jet A-1, which is a widely used petroleum-based fuel, and four synthetically produced alternative jet fuels. The main goals of this part of the thesis are to compare the soot emission levels of the alternative fuels to those of a standard fuel, Jet A-1, and to determine the effect of fuel chemical composition on soot formation characteristics. To achieve these goals, experimental measurements are constructed and performed for flame temperature, soot concentration, soot particle size, and soot aggregate structure in the flames of pre-vaporized jet fuels. The results show that a considerable reduction in soot production, compared to the standard fuel, can be obtained by using synthetic fuels which will help in addressing future regulations. A strong correlation between the aromatic content of the fuels and the soot concentration levels in the flames is observed. The second part of this thesis presents the development and experimental validation of a fully-coupled soot formation model for laminar coflow jet fuel diffusion flames. The model is coupled to a detailed kinetic mechanism to predict the chemical structure of the flames and soot precursor concentrations. This model also provides information on size and morphology of soot particles. The flames of a three-component surrogate for Jet A-1, a three-component surrogate for a synthetic jet fuel, and pure n-decane are simulated using this model. Concentrations of major gaseous species and flame temperatures are well predicted by the model. Soot volume fractions are predicted reasonably well everywhere in the flame, except near the flame centerline where soot concentrations are underpredicted by a factor of up to five. There is an excellent

  1. Modeling and experimental studies to optimize the performance of a hydrogen - bromine fuel cell

    NASA Astrophysics Data System (ADS)

    Yarlagadda, Venkata Raviteja

    The regenerative Hydrogen-Bromine (H2-Br 2) fuel cells are considered to be one of the viable systems for large scale energy storage because of their high energy conversion efficiency, flexible operation, highly reversible reactions and low capital cost. The preliminary performance of a H2-Br2 fuel cell using both conventional as well as novel materials (Nafion and electrospun composite membranes along with platinum and rhodium sulfide electrocatalysts) was discussed. A maximum power density of 0.65 W/cm2 was obtained with a thicker Br 2 electrode (780 mum) and cell temperature of 45°C. The active area and wetting characteristics of Br2 electrodes were improved upon by either pre-treating with HBr or boiling them in de-ionized water. On the other hand, similar or better performances were obtained using dual fiber electrospun composite membranes (maximum power densities of 0.61 W/cm2 and 0.45 W/cm2 obtained with 25 mum and 65 mum electrospun membranes at 45°C) versus using Nafion membranes (maximum power densities of 0.52 W/cm 2 and 0.41 W/cm2 obtained with Nafion 212 and Nafion 115 membranes at 45°C). The rhodium sulfide (RhxSy) electrocatalyst proved to be more stable in the presence of HBr/Br2 than pure Pt. However, the H2 oxidation activity on RhxS y was quite low compared to that of Pt. In conclusion, a stable H 2 electrocatalyst that can match the hydrogen oxidation activity obtained with Pt and a membrane with low Br2/Br- permeability are essential to prolong the lifetime of a H2-Br2 fuel cell. A 1D mathematical model was developed to serve as a theoretical guiding tool for the experimental studies. The impact of convective and diffusive transport and kinetic rate on the performance of a H2-Br2 fuel cell is shown in this study. Of the two flow designs (flow-by and flow-through) incorporated in this study, the flow-through design demonstrated better performance, which can be attributed to the dominant convective transport inside the porous electrode. Both

  2. Coprocessing solvent-extraction flowsheet studies for LWR and FBR fuels

    SciTech Connect

    Collins, E.D.; Benker, D.E.; Bigelow, J.E.; Chattin, F.R.; King, L.J.; Lloyd, M.H.; Ross, R.G.; Stacy, R.G.; Savage, H.C.

    1982-01-01

    Coprocessing solvent extraction studies using irradiated LWR and FBR fuels have indicated the need for an efficient feed clarification. A potentially useful filtration method for fulfilling this need has been demonstrated. Conditions necessary for the satisfactory use of unstabilized hydroxylamine nitrate (HAN) or nitrous acid as the reducing agent for Pu(IV) during reductive stripping operations have been defined. Both partial partitioning and total costripping operations have been demonstrated. In addition, solvent degradation product measurements have been made, and the effect of the presence of DBP during uranium-plutonium stripping operations has been determined.

  3. Study of fuel cell on-site, integrated energy systems in residential/commercial applications

    NASA Technical Reports Server (NTRS)

    Wakefield, R. A.; Karamchetty, S.; Rand, R. H.; Ku, W. S.; Tekumalla, V.

    1980-01-01

    Three building applications were selected for a detailed study: a low rise apartment building; a retail store, and a hospital. Building design data were then specified for each application, based on the design and construction of typical, actual buildings. Finally, a computerized building loads analysis program was used to estimate hourly end use load profiles for each building. Conventional and fuel cell based energy systems were designed and simulated for each building in each location. Based on the results of a computer simulation of each energy system, levelized annual costs and annual energy consumptions were calculated for all systems.

  4. A Survey of Studies on Ignition and Burn of Inertially Confined Fuels

    NASA Astrophysics Data System (ADS)

    Atzeni, Stefano

    2016-10-01

    A survey of studies on ignition and burn of inertial fusion fuels is presented. Potentials and issues of different approaches to ignition (central ignition, fast ignition, volume ignition) are addressed by means of simple models and numerical simulations. Both equimolar DT and T-lean mixtures are considered. Crucial issues concerning hot spot formation (implosion symmetry for central ignition; igniting pulse parameters for fast ignition) are briefly discussed. Recent results concerning the scaling of the ignition energy with the implosion velocity and constrained gain curves are also summarized.

  5. Does Smoke from Biomass Fuel Contribute to Anemia in Pregnant Women in Nagpur, India? A Cross-Sectional Study

    PubMed Central

    Page, Charlotte M.; Patel, Archana; Hibberd, Patricia L.

    2015-01-01

    Background Anemia affects upwards of 50% of pregnant women in developing countries and is associated with adverse outcomes for mother and child. We hypothesized that exposure to smoke from biomass fuel – which is widely used for household energy needs in resource-limited settings – could exacerbate anemia in pregnancy, possibly as a result of systemic inflammation. Objective To evaluate whether exposure to smoke from biomass fuel (wood, straw, crop residues, or dung) as opposed to clean fuel (electricity, liquefied petroleum gas, natural gas, or biogas) is an independent risk factor for anemia in pregnancy, classified by severity. Methods A secondary analysis was performed using data collected from a rural pregnancy cohort (N = 12,782) in Nagpur, India in 2011-2013 as part of the NIH-funded Maternal and Newborn Health Registry Study. Multinomial logistic regression was used to estimate the effect of biomass fuel vs. clean fuel use on anemia in pregnancy, controlling for maternal age, body mass index, education level, exposure to household tobacco smoke, parity, trimester when hemoglobin was measured, and receipt of prenatal iron and folate supplements. Results The prevalence of any anemia (hemoglobin < 11 g/dl) was 93% in biomass fuel users and 88% in clean fuel users. Moderate-to-severe anemia (hemoglobin < 10 g/dl) occurred in 53% and 40% of the women, respectively. Multinomial logistic regression showed higher relative risks of mild anemia in pregnancy (hemoglobin 10-11 g/dl; RRR = 1.38, 95% CI = 1.19-1.61) and of moderate-to-severe anemia in pregnancy (RRR = 1.79, 95% CI = 1.53-2.09) in biomass fuel vs. clean fuel users, after adjusting for covariates. Conclusion In our study population, exposure to biomass smoke was associated with higher risks of mild and moderate-to-severe anemia in pregnancy, independent of covariates. Trial Registration ClinicalTrials.gov NCT 01073475 PMID:26024473

  6. Study of Hydrogen Recovery Systems for Gas Vented While Refueling Liquid-Hydrogen Fueled Aircraft

    NASA Technical Reports Server (NTRS)

    Baker, C. R.

    1979-01-01

    Methods of capturing and reliquefying the cold hydrogen vapor produced during the fueling of aircraft designed to utilize liquid hydrogen fuel were investigated. An assessment of the most practical, economic, and energy efficient of the hydrogen recovery methods is provided.

  7. Advanced LWR Nuclear Fuel Cladding System Development Trade-Off Study

    SciTech Connect

    Kristine Barrett; Shannon Bragg-Sitton

    2012-09-01

    The Advanced Light Water Reactor (LWR) Nuclear Fuel Development Research and Development (R&D) Pathway encompasses strategic research focused on improving reactor core economics and safety margins through the development of an advanced fuel cladding system. To achieve significant operating improvements while remaining within safety boundaries, significant steps beyond incremental improvements in the current generation of nuclear fuel are required. Fundamental improvements are required in the areas of nuclear fuel composition, cladding integrity, and the fuel/cladding interaction to allow power uprates and increased fuel burn-up allowance while potentially improving safety margin through the adoption of an “accident tolerant” fuel system that would offer improved coping time under accident scenarios. With a development time of about 20 – 25 years, advanced fuel designs must be started today and proven in current reactors if future reactor designs are to be able to use them with confidence.

  8. Experimental and Modeling Study of the Flammability of Fuel Tank Headspace Vapors from Ethanol/Gasoline Fuels; Phase 3: Effects of Winter Gasoline Volatility and Ethanol Content on Blend Flammability; Flammability Limits of Denatured Ethanol

    SciTech Connect

    Gardiner, D. P.; Bardon, M. F.; Clark, W.

    2011-07-01

    This study assessed differences in headspace flammability for summertime gasolines and new high-ethanol content fuel blends. The results apply to vehicle fuel tanks and underground storage tanks. Ambient temperature and fuel formulation effects on headspace vapor flammability of ethanol/gasoline blends were evaluated. Depending on the degree of tank filling, fuel type, and ambient temperature, fuel vapors in a tank can be flammable or non-flammable. Pure gasoline vapors in tanks generally are too rich to be flammable unless ambient temperatures are extremely low. High percentages of ethanol blended with gasoline can be less volatile than pure gasoline and can produce flammable headspace vapors at common ambient temperatures. The study supports refinements of fuel ethanol volatility specifications and shows potential consequences of using noncompliant fuels. E85 is flammable at low temperatures; denatured ethanol is flammable at warmer temperatures. If both are stored at the same location, one or both of the tanks' headspace vapors will be flammable over a wide range of ambient temperatures. This is relevant to allowing consumers to splash -blend ethanol and gasoline at fueling stations. Fuels compliant with ASTM volatility specifications are relatively safe, but the E85 samples tested indicate that some ethanol fuels may produce flammable vapors.

  9. A Study on the Conceptual Design of a 1,500 MWe Passive PWR with Annular Fuel

    SciTech Connect

    Kwi Lim Lee; Soon Heung Chang

    2004-07-01

    In this study, the preliminary conceptual design of a 1500 MWe pressurized water reactor (PWR) with annular fuel has been performed. This design is derived from the AP1000 which is a 1000 MWe PWR with two-loop. However, the present design is a 1500 MWe PWR with three-loop, passive safety features and extensive plant simplifications to enhance the construction, operation, and maintenance. The preliminary design parameters of this reactor have been determined through simple relation to those of AP1000 for reactor, reactor coolant system, and passive safety injection system. Using the MATRA code, we analyze the core designs for two alternatives on fuel assembly types: solid fuel and annular fuel. The performance of reactor cooling systems is evaluated through the accident of the cold leg break in the core makeup tank loop by using MARS2.1 code. This study presents the developmental strategy, preliminary design parameters and safety analysis results. (authors)

  10. Effects of coal-derived trace species on the performance of molten carbonate fuel cells. Topical report on thermochemical studies

    SciTech Connect

    Pigeaud, A.

    1991-10-01

    The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

  11. An experimental study of the fuel dilution effect on the propagation of methane-air tribrachial flames

    SciTech Connect

    Seo, Jeong Il; Shin, Hyun Dong; Kim, Nam Il

    2008-05-15

    The effects of fuel dilution with nitrogen on the propagation of tribrachial flames were studied experimentally using a multislot burner, which can stabilize lifted flames at low concentration gradients. Three fuel dilutions with nitrogen (N{sub 2} 0%, 25%, and 50% dilution) were employed. The lift-off height and OH-radical content of the flames were measured using an intensified CCD camera and an OH-PLIF scheme. Regardless of the fuel dilution mole fractions, the lift-off height of the tribrachial flames exhibited U-shaped trends with a minimal value during the increase of the concentration gradients. This implies that the propagation velocity is maximized at a specific concentration gradient regardless of the fuel dilution. Overall, the propagation velocity of the tribrachial flame was reduced by the fuel dilution, and the fuel dilution weakly affected the generation of the diffusion flame. The OH radicals in the diffusion branch became prominently active at the critical concentration gradient and these phenomena were more clearly detected at higher fuel dilution mole fractions. The decrease of the three modes of the OH radicals in a streamwise direction is discussed regarding the relation of the diffusion branch to the propagation velocity of the tribrachial flames. It is suggested that the effect of the diffusion branch on the propagation velocity of tribrachial flames needs to be reconsidered, especially when the concentration gradient is small. (author)

  12. A segmented model for studying water transport in a PEM fuel cell

    NASA Astrophysics Data System (ADS)

    Chen, Yong-Song

    Fuel Cells are devices that generate electricity by electrochemically combining hydrogen and oxygen. Water management plays an important role in the durability and efficiency of a proton exchange membrane fuel cell (PEMFC). In this study, single cells are modeled as lumped models consisting of 15 interconnected segments, which are linked according to the flow field patterns of the anode and cathode but they are treated as individual lumped elements. Parameters of this model were calibrated based on neutron radiography experimental results obtained at the NIST Center for Neutron Research (NCNR). Three special single cells were designed for the purpose of detecting liquid water and water vapor simultaneously. The major difference between our design and traditional flow field designs is the fact the anode channels and cathode channels were shifted sideways, so that the anode and cathode channels do not overlap in the majority of the active areas. The liquid water is measured by using neutron radiography. The water vapor is measured by the twenty relative humidity sensors embedded in the anode and the cathode flow field plates. The effects of relative humidity and stoichiometry of cathode inlet on relative humidity distribution in the channels and on water accumulation in the GDLs were investigated in this study. The liquid water accumulation at steady-state was calculated by using imaging mask techniques and least-squares method. It is demonstrated that liquid water tends to accumulates in the gas diffusion layers under the rib. Modeling results suggest that opposite flow direction improve the cell performance at low humidity conditions. Accordingly, this segmented model is useful in designing flow field patterns and comparing the influence of different flow field patterns before they are machined on the flow field plates. That reduces the cost of developing and designing a fuel cell.

  13. Study of the competitive viability of minority fuel oil marketers. Final report

    SciTech Connect

    1981-09-30

    Previous studies on the competitive viability of the fuel oil heating market had addressed some of the unique problems facing minority fuel oil marketers (MFMs) within the total market sector (TMS). This study focused on identifying and developing quantitative information on MFMs in the TMS. The specific objective was to determine whether the business problems experienced by MFMs were directly related to their minority status or were characterstic of any firm in the TMS operating under comparable conditions. As an overall conclusion, thorough investigation of the MFMs considered to constitute the universe of minoriy firms within the TMS did not reveal any evidence of overt discrimination affecting the competitive viability of MFMs. Upon analysis, the problems reported by MFMs could not be reasonably ascribed to discrimination on the basis of their minority business status. The study, however, did point up problems unique to MFMs as the result of typical operational and financial characteristics. For example, MFMs, compared to the TMS norm, have not been in the market as long and are smaller in terms of total assets, number of employees, number of trucks, number of accounts and annual volume of oil delivered. Their primary customers are low-income families in urban areas. Financial indicators suggest that the average MFM does not have long-term financial stability. The basis for this overall conclusion, derived by analyses of information from MFMs, as well as many independent sources, is summarized in three parts: (1) MFM industry profile; (2) financial analyses; and (3) problem analyses.

  14. Study of Different Al/Mg Powders in Hydroreactive Fuel Propellant Used for Water Ramjet

    NASA Astrophysics Data System (ADS)

    Huang, Hai-Tao; Zou, Mei-Shuai; Guo, Xiao-Yan; Yang, Rong-Jie; Li, Yun-Kai; Jiang, En-Zhou; Li, Zhong-Shan

    2014-05-01

    Experiments were conducted to study the effect of magnesium-aluminum alloy on the combustion performance of hydroreactive fuel propellants. The raw metal powders added to the propellants were ball-milled magnesium-50% aluminum alloy (m-AM), magnesium-50% aluminum alloy (AM), and Al and magnesium (Mg) powders, which were characterized using scanning electron microscopy, X-ray diffraction (XRD), and simultaneous thermogravimetric analysis (TGA). A high-pressure combustor and a metal/steam reactor were used to simulate the two-stage combustion of hydroreactive propellants used for a water ramjet. The combustion performance of the metal powders in propellant was studied experimentally, and the efficiency of the Al reaction in the propellants during the two-stage combustion was calculated. TGA traces in air indicated that the oxidation onset temperature of AM powders is much lower than for both Mg and Al powders. The XRD patterns for the AM and m-AM alloys exhibited Al12Mg17 diffraction peaks. The hydroreactive fuel propellant systems with added m-AM powder exhibited good performance in terms of burning rate, combustion heat, and the Al reaction efficiency, which was better than that for the propellants containing AM, Mg, and Al powders. At the pressure studied (3.0 MPa), the burning rate of the m-AM-containing propellant was found to be 15 mm s-1, and the heat of primary combustion was 6,878.1 kJ kg-1.

  15. Experimental and numerical studies of burning velocities and kinetic modeling for practical and surrogate fuels

    NASA Astrophysics Data System (ADS)

    Zhao, Zhenwei

    To help understand the fuel oxidation process in practical combustion environments, laminar flame speeds and high temperature chemical kinetic models were studied for several practical fuels and "surrogate" fuels, such as propane, dimethyl ether (DME), and primary reference fuel (PRF) mixtures, gasoline and n-decane. The PIV system developed for the present work is described. The general principles for PIV measurements are outlined and the specific considerations are also reported. Laminar flame speeds were determined for propane/air over a range of equivalence ratios at initial temperature of 298 K, 500 K and 650 K and atmospheric pressure. Several data sets for propane/air laminar flame speeds with N 2 dilution are also reported. These results are compared to the literature data collected at the same conditions. The propane flame speed is also numerically calculated with a detailed kinetic model and multi component diffusion, including Soret effects. This thesis also presents experimentally determined laminar flame speeds for primary reference fuel (PRF) mixtures of n-heptane/iso-octane and real gasoline fuel at different initial temperature and at atmospheric pressure. Nitrogen dilution effects on the laminar flame speed are also studied for selected equivalence ratios at the same conditions. A minimization of detailed kinetic model for PRF mixtures on laminar flame speed conditions was performed and the measured flame speeds were compared with numerical predictions using this model. The measured laminar flame speeds of n-decane/air mixtures at 500 K and at atmospheric pressure with and without dilution were determined. The measured flame speeds are significantly different that those predicted using existing published kinetic models, including a model validated previously against high temperature data from flow reactor, jet-stirred reactor, shock tube ignition delay, and burner stabilized flame experiments. A significant update of this model is described which

  16. Fuel characteristics and pyrolysis studies of solvent extractables and residues from the evergreen shrub Calotropis procera

    SciTech Connect

    Erdman, M.D.; Gregorski, K.S.; Pavlath, A.E.

    1984-01-01

    Solvent extractables and residues from milkweed were evaluated as sources of liquid and solid fuels. Selected chemical, physical and pyrolytic determinations of the extractables and residues indicated that hexane extract is a potentially valuable, high density fuel resource. Methanol extract was shown to be a lower energy, highly toxic extract. Extracted residues were demonstrated to be valuable as solid fuel energy resources. 31 references.

  17. Experimental study of the effect of spacer grid on the flow structure in fuel assemblies of the AES 2006 reactor

    NASA Astrophysics Data System (ADS)

    Kashinskii, O. N.; Lobanov, P. D.; Pribaturin, N. A.; Kurdyumov, A. S.; Volkov, S. E.

    2013-01-01

    Results from an experimental study of the local hydrodynamic structure of liquid flow in a 37-cell model simulating a fuel assembly used in the AES-2006 reactor are presented. Special attention is paid to the effect of spacer grid on flow hydrodynamics. Data on variations of the local and integral values of the liquid axial velocity and friction stress on the fuel rod simulator's wall with distance from the grid are given.

  18. Numerical and Experimental Study of Mixing Processes Associated with Hydrogen and High Hydrogen Content Fuels

    SciTech Connect

    McDonell, Vincent; Hill, Scott; Akbari, Amin; McDonell, Vincent

    2011-09-30

    As simulation capability improves exponentially with increasingly more cost effective CPUs and hardware, it can be used ?routinely? for engineering applications. Many commercial products are available and they are marketed as increasingly powerful and easy to use. The question remains as to the overall accuracy of results obtained. To support the validation of the CFD, a hierarchical experiment was established in which the type of fuel injection (radial, axial) as well as level of swirl (non-swirling, swirling) could be systematically varied. The effort was limited to time efficient approaches (i.e., generally RANS approaches) although limited assessment of time resolved methods (i.e., unsteady RANS and LES) were considered. Careful measurements of the flowfield velocity and fuel concentration were made using both intrusive and non-intrusive methods. This database was then used as the basis for the assessment of the CFD approach. The numerical studies were carried out with a statistically based matrix. As a result, the effect of turbulence model, fuel type, axial plane, turbulent Schmidt number, and injection type could be studied using analysis of variance. The results for the non-swirling cases could be analyzed as planned, and demonstrate that turbulence model selection, turbulence Schmidt number, and the type of injection will strongly influence the agreement with measured values. Interestingly, the type of fuel used (either hydrogen or methane) has no influence on the accuracy of the simulations. For axial injection, the selection of proper turbulence Schmidt number is important, whereas for radial injection, the results are relatively insensitive to this parameter. In general, it was found that the nature of the flowfield influences the performance of the predictions. This result implies that it is difficult to establish a priori the ?best? simulation approach to use. However, the insights from the relative orientation of the jet and flow do offer some

  19. Advanced Test Reactor LEU Fuel Conversion Feasibility Study (2006 Annual Report)

    SciTech Connect

    Gray S. Chang; Richard G. Ambrosek; Misti A. Lillo

    2006-12-01

    The Advanced Test Reactor (ATR) is a high power density and high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth with a maximum unperturbed thermal neutron flux rating of 1.0 x 1015 n/cm2–s. Because of these operating parameters, and the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. The present work investigates the necessary modifications and evaluates the subsequent operating effects of this conversion. A detailed plate-by-plate MCNP ATR 1/8th core model was developed and validated for a fuel cycle burnup comparison analysis. Using the current HEU U 235 enrichment of 93.0 % as a baseline, an analysis can be performed to determine the low-enriched uranium (LEU) density and U-235 enrichment required in the fuel meat to yield an equivalent K-eff between the HEU core and the LEU core versus effective full power days (EFPD). The MCNP ATR 1/8th core model will be used to optimize the U-235 loading in the LEU core, such that the differences in K-eff and heat profile between the HEU and LEU core can be minimized for operation at 125 EFPD with a total core power of 115 MW. The depletion methodology, Monte-Carlo coupled with ORIGEN2 (MCWO), was used to calculate K-eff versus EFPDs. The MCWO-calculated results for the LEU case demonstrated adequate excess reactivity such that the K-eff versus EFPDs plot is similar in shape to the reference ATR HEU case. The LEU core conversion feasibility study can also be used to optimize the U-235 content of each fuel plate, so that the relative radial fission heat flux profile is bounded by the reference ATR HEU case. The detailed radial, axial, and azimuthal heat flux profiles of the HEU and optimized LEU cases have been investigated. However, to demonstrate that the LEU core fuel cycle performance can

  20. Structural dynamics and activity of nanocatalysts inside fuel cells by in operando atomic pair distribution studies

    NASA Astrophysics Data System (ADS)

    Petkov, Valeri; Prasai, Binay; Shan, Shiyao; Ren, Yang; Wu, Jinfang; Cronk, Hannah; Luo, Jin; Zhong, Chuan-Jian

    2016-05-01

    Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE-XRD) we tracked the evolution of the atomic structure and activity of noble metal-transition metal (NM-TM) nanocatalysts for ORR as they function at the cathode of a fully operational proton exchange membrane fuel cell (PEMFC). Experimental HE-XRD data were analysed in terms of atomic pair distribution functions (PDFs) and compared to the current output of the PEMFC, which was also recorded during the experiments. The comparison revealed that under actual operating conditions, NM-TM nanocatalysts can undergo structural changes that differ significantly in both length-scale and dynamics and so can suffer losses in their ORR activity that differ significantly in both character and magnitude. Therefore we argue that strategies for reducing ORR activity losses should implement steps for achieving control not only over the length but also over the time-scale of the structural changes of NM-TM NPs that indeed occur during PEMFC operation. Moreover, we demonstrate how such a control can be achieved and thereby the performance of PEMFCs improved considerably. Last but not least, we argue that the unique capabilities of in operando HE-XRD coupled to atomic PDF analysis to characterize active nanocatalysts inside operating fuel cells both in a time-resolved manner and with atomic level resolution, i.e. in 4D, can serve well the ongoing search for nanocatalysts that deliver more with less platinum.Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE

  1. Feasibility Study on Thermal-Hydraulic Performance of Innovative Water Reactor for Flexible Fuel Cycle (FLWR)

    SciTech Connect

    Akira, Ohnuki; Kazuyuki, Takase; Masatoshi, Kureta; Hiroyuki, Yoshida; Hidesada, Tamai; Wei, Liu; Toru, Nakatsuka; Takeharu, Misawa; Hajime, Akimoto

    2006-07-01

    R and D project to investigate thermal-hydraulic performance in tight-lattice rod bundles of Innovative Water Reactor for Flexible Fuel Cycle (FLWR) is started at Japan Atomic Energy Agency (JAEA) in collaboration with power company, reactor vendors, universities since 2002. The FLWR can attain the favorable characteristics such as effective utilization of uranium resources, multiple recycling of plutonium, high burn-up and long operation cycle, based on matured LWR technologies. MOX fuel assemblies with tight lattice arrangement are used to increase the conversion ratio by reducing the moderation of neutron. Increasing the in-core void fraction also contributes to the reduction of neutron moderation. The confirmation of thermal-hydraulic feasibility is one of the most important R and D items for the FLWR because of the tight lattice configuration. In this paper, we will show the R and D plan and summarize experimental studies. The experimental study is performed mainly using large-scale (37-rod bundle) test facility. Most important objective of the large-scale test is to resolve a fundamental subject whether the core cooling under a tight-lattice configuration is feasible. The characteristics of critical power and flow behavior are investigated under different geometrical configuration and boundary conditions. The configuration parameter is the gap between rods (FY2004) and the rod bowing (FY2005). We have confirmed the thermal-hydraulic feasibility from the experimental results. (authors)

  2. Hydrogen uptake in Zircaloy-2 reactor fuel claddings studied with elastic recoil detection

    NASA Astrophysics Data System (ADS)

    Rajasekhara, S.; Doyle, B. L.; Enos, D. G.; Clark, B. G.

    2013-04-01

    The recent trend towards a high burn-up discharge spent nuclear fuel necessitates a thorough understanding of hydrogen uptake in Zr-based cladding materials that encapsulate spent nuclear fuel. Although it is challenging to experimentally replicate exact conditions in a nuclear reactor that lead to hydrogen uptake in claddings, in this study we have attempted to understand the kinetics of hydrogen uptake by first electrolytically charging Zircaloy-2 (Zr-2) cladding material for various durations (100 to 2,600 s), and subsequently examining hydrogen ingress with elastic recoil detection (ERD) and transmission electron microscopy (TEM). To understand the influence of irradiation damage defects on hydrogen uptake, an analogous study was performed on ion - irradiated (0.1, 1 and 25 dpa) Zr-2. Analysis of ERD data from the un-irradiated Zr-2 suggests that the growth of the hydride layer is diffusion controlled, and preliminary TEM results support this assertion. In un-irradiated Zr-2, the diffusivity of hydrogen in the hydride phase was found to be approximately 1.1 × 10-11 cm2/s, while the diffusivity in the hydride phase for lightly irradiated (0.1 and 1 dpa) Zr-2 is an order of magnitude lower. Irradiation to 25 dpa results in a hydrogen diffusivity that is comparable to the un-irradiated Zr-2. These results are compared with existing literature on hydrogen transport in Zr - based materials.

  3. Head-end reprocessing studies of H.B. Robinson-2 fuel: II. Parametric voloxidation studies

    SciTech Connect

    Goode, J.H.; Stacy, R.G.; Vaughen, V.C.A.

    1980-05-01

    A series of hot-cell tests was conducted with UO{sub 2} that had been irradiated to an average of 28,000 MWd/t in the H.B. Robinson-2 reactor of the Carolina Power and Light Company. The tests examined the effects of temperature and of the rate of oxygen supply on the release of gaseous and semivolatile fission products, while the fuel fragments were tumbled at 12 rpm during voloxidation - the high-temperature oxidation of UO{sub 2} to U{sub 3}O{sub 8}. The experiments showed that >99.9% of the tritium in the irradiated UO{sub 2} was released to the off-gas stream at temperatures of 480 and 550{sup 0}C and at oxygen feed rates ranging from 0.1 to 1.2 mol/h. The release of {sup 85}Kr varied from 2 to 7% of the fuel inventory. The U{sub 3}O{sub 8} product ({similar_to}99% smaller than 44 {mu}m) was easily dissolved in 7 M HNO{sub 3}. One 2-h leach in 7 M HNO{sub 3} dissolved {similar_to}99.5% of the heavy metals; a second 2-h leach in 7 M HNO{sub 3} brought the total to >99.98%. Voloxidation did not affect the final solubility of the uranium and plutonium but did increase the weight of the insoluble fission product residue from 0.18% of the irradiated UO{sub 2} to {similar_to}0.62%.

  4. Structural dynamics and activity of nanocatalysts inside fuel cells by in operando atomic pair distribution studies.

    PubMed

    Petkov, Valeri; Prasai, Binay; Shan, Shiyao; Ren, Yang; Wu, Jinfang; Cronk, Hannah; Luo, Jin; Zhong, Chuan-Jian

    2016-05-19

    Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE-XRD) we tracked the evolution of the atomic structure and activity of noble metal-transition metal (NM-TM) nanocatalysts for ORR as they function at the cathode of a fully operational proton exchange membrane fuel cell (PEMFC). Experimental HE-XRD data were analysed in terms of atomic pair distribution functions (PDFs) and compared to the current output of the PEMFC, which was also recorded during the experiments. The comparison revealed that under actual operating conditions, NM-TM nanocatalysts can undergo structural changes that differ significantly in both length-scale and dynamics and so can suffer losses in their ORR activity that differ significantly in both character and magnitude. Therefore we argue that strategies for reducing ORR activity losses should implement steps for achieving control not only over the length but also over the time-scale of the structural changes of NM-TM NPs that indeed occur during PEMFC operation. Moreover, we demonstrate how such a control can be achieved and thereby the performance of PEMFCs improved considerably. Last but not least, we argue that the unique capabilities of in operando HE-XRD coupled to atomic PDF analysis to characterize active nanocatalysts inside operating fuel cells both in a time-resolved manner and with atomic level resolution, i.e. in 4D, can serve well the ongoing search for nanocatalysts that deliver more with less platinum. PMID:27160891

  5. Structural dynamics and activity of nanocatalysts inside fuel cells by in operando atomic pair distribution studies.

    PubMed

    Petkov, Valeri; Prasai, Binay; Shan, Shiyao; Ren, Yang; Wu, Jinfang; Cronk, Hannah; Luo, Jin; Zhong, Chuan-Jian

    2016-05-19

    Here we present the results from a study aimed at clarifying the relationship between the atomic structure and activity of nanocatalysts for chemical reactions driving fuel cells, such as the oxygen reduction reaction (ORR). In particular, using in operando high-energy X-ray diffraction (HE-XRD) we tracked the evolution of the atomic structure and activity of noble metal-transition metal (NM-TM) nanocatalysts for ORR as they function at the cathode of a fully operational proton exchange membrane fuel cell (PEMFC). Experimental HE-XRD data were analysed in terms of atomic pair distribution functions (PDFs) and compared to the current output of the PEMFC, which was also recorded during the experiments. The comparison revealed that under actual operating conditions, NM-TM nanocatalysts can undergo structural changes that differ significantly in both length-scale and dynamics and so can suffer losses in their ORR activity that differ significantly in both character and magnitude. Therefore we argue that strategies for reducing ORR activity losses should implement steps for achieving control not only over the length but also over the time-scale of the structural changes of NM-TM NPs that indeed occur during PEMFC operation. Moreover, we demonstrate how such a control can be achieved and thereby the performance of PEMFCs improved considerably. Last but not least, we argue that the unique capabilities of in operando HE-XRD coupled to atomic PDF analysis to characterize active nanocatalysts inside operating fuel cells both in a time-resolved manner and with atomic level resolution, i.e. in 4D, can serve well the ongoing search for nanocatalysts that deliver more with less platinum.

  6. Neutronics study of LEU fuel options for the HFR-Petten

    SciTech Connect

    Deen, J.R.; Snelgrove, J.L.

    1984-01-01

    The standard HEU fuel cycle characteristics are compared with those of several different LEU fuel cycles in the new vessel configuration. The primary design goals were to provide similar reactivity performance and neutron flux profiles with a minimal increase in /sup 235/U loading. The fuel cycle advantages of Cd burnable absorbers over /sup 10/B are presented. The LEU fuel cycle requirements were calculated also for an extended 32-day cycle and for a reload batch size reduction from six to five standard elements for the standard 26-day cycle. The effects of typical in-core experiments upon neutron flux profiles and fuel loading requirements are also presented.

  7. Well-to-Wheels Analysis of Advanced Fuel/Vehicle Systems: A North American Study of Energy Use, Greenhouse Gas Emissions, and Criteria Pollutant Emissions

    SciTech Connect

    Brinkman, Norman; Wang, Michael; Weber, Trudy; Darlington, Thomas

    2005-05-01

    An accurate assessment of future fuel/propulsion system options requires a complete vehicle fuel-cycle analysis, commonly called a well-to-wheels (WTW) analysis. This WTW study analyzes energy use and emissions associated with fuel production (or well-to-tank [WTT]) activities and energy use and emissions associated with vehicle operation (or tank-to-wheels [TTW]) activities.

  8. A Deterministic Study of the Deficiency of the Wigner-Seitz Approximation for Pu/MOX Fuel Pins

    SciTech Connect

    DeHart, M.D.

    1999-09-27

    The Wigner-Seitz pin-cell approximation has long been applied as a modeling approximation in analysis of UO2 lattice fuel cells. In the past, this approximation has been appropriate for such fuel. However, with increasing attention drawn to mixed-oxide (MOX) fuels with significant plutonium content, it is important to understand the implications of the approximation in a uranium-plutonium matrix. The special geometric capabilities of the deterministic NEWT computer code have been used to assess the adequacy of the Wigner-Seitz cell in such an environment, as part of a larger study of computational aspects of MOX fuel modeling. Results of calculations using various approximations and boundary conditions are presented, and are validated by comparison to results obtained using KENO V.a and XSDRNPM.

  9. A separate effect study of the influence of metallic fission products on CsI radioactive release from nuclear fuel

    NASA Astrophysics Data System (ADS)

    Di Lemma, F. G.; Colle, J. Y.; Beneš, O.; Konings, R. J. M.

    2015-10-01

    The chemistry of cesium and iodine is of main importance to quantify the radioactive release in case of a nuclear reactor accident, or sabotage involving irradiated nuclear materials. We studied the interaction of CsI with different metallic fission products such as Mo and Ru. These elements can be released from nuclear fuel when exposed to oxidising conditions, as in the case of contact of overheated nuclear fuel with air (e.g. in a spent fuel cask sabotage, uncovering of a spent fuel pond, or air ingress accidents). Experiments were performed by vaporizing mixtures of the compounds in air, and analysing the produced aerosols in view of a possible gas-gas and gas-aerosol reactions between the compounds. These results were compared with the gaseous species predicted by thermochemical equilibrium calculations and experimental equilibrium vaporization tests using Knudsen Effusion Mass Spectrometry.

  10. Application of photon-correlation spectroscopy and quartz-crystal microbalance to the study of thermally stressed jet fuel

    SciTech Connect

    Vilimpoc, V.; Sarka, B.

    1997-02-01

    The thermal degradation of jet fuel is characterized by the formation of particulates and gum deposits. The lack of sensitivity of previous methods of testing thermally stressed jet fuel required acceleration of the test conditions. Recently, two techniques have been integrated into a single instrumented platform to permit simultaneous in-situ real-time measurements of particle-size growth rate and surface mass-deposition rate in these fuels. With this arrangement, the particle growth rate is determined using photon-correlation spectroscopy (PCS), and the surface mass-deposition rate is measured with a quartz-crystal microbalance (QCM). The resolution and sensitivity of these techniques permit the study of particle-size growth rate and mass-deposition rate at temperatures and times representative of those found in aviation fuel systems.

  11. Experimental and Analytical Study of Balanced-Diaphragm Fuel Distributors for Gas-Turbine Engines

    NASA Technical Reports Server (NTRS)

    Straight, David M.; Gold, Harold

    1950-01-01

    A method of distributing fuel equally to a plurality of spray nozzles in a gas-turbine engine by means of balanced-diaphragm fuel distributors is presented. The experimental performance of three of eight possible distributor arrangements are discussed. An analysis of all eight arrangements is included. Criterions are given for choosing a fuel-distributor arrangement to meet specific fuel-system requirements of fuel-distribution accuracy, spray-nozzle pressure variations, and fuel-system pressures. Data obtained with a model of one distributor arrangement indicated a maximum deviation from perfect distribution of 3.3 percent for a 44 to 1 range (19.5 to 862 lb/hr) of fuel-flow rates. The maximum distributor pressure drop was 125 pounds per square inch. The method used to obtain the required wide range of flow control in the distributor valves consisted in varying the length of a constant-area flow path.

  12. A study on emission characteristics of an EFI engine with ethanol blended gasoline fuels

    NASA Astrophysics Data System (ADS)

    He, Bang-Quan; Wang, Jian-Xin; Hao, Ji-Ming; Yan, Xiao-Guang; Xiao, Jian-Hua

    The effect of ethanol blended gasoline fuels on emissions and catalyst conversion efficiencies was investigated in a spark ignition engine with an electronic fuel injection (EFI) system. The addition of ethanol to gasoline fuel enhances the octane number of the blended fuels and changes distillation temperature. Ethanol can decrease engine-out regulated emissions. The fuel containing 30% ethanol by volume can drastically reduce engine-out total hydrocarbon emissions (THC) at operating conditions and engine-out THC, CO and NO x emissions at idle speed, but unburned ethanol and acetaldehyde emissions increase. Pt/Rh based three-way catalysts are effective in reducing acetaldehyde emissions, but the conversion of unburned ethanol is low. Tailpipe emissions of THC, CO and NO x have close relation to engine-out emissions, catalyst conversion efficiency, engine's speed and load, air/fuel equivalence ratio. Moreover, the blended fuels can decrease brake specific energy consumption.

  13. An Experimental Study of Upward Burning Over Long Solid Fuels: Facility Development and Comparison

    NASA Technical Reports Server (NTRS)

    Kleinhenz, Julie; Yuan, Zeng-Guang

    2011-01-01

    As NASA's mission evolves, new spacecraft and habitat environments necessitate expanded study of materials flammability. Most of the upward burning tests to date, including the NASA standard material screening method NASA-STD-6001, have been conducted in small chambers where the flame often terminates before a steady state flame is established. In real environments, the same limitations may not be present. The use of long fuel samples would allow the flames to proceed in an unhindered manner. In order to explore sample size and chamber size effects, two large chambers were developed at NASA GRC under the Flame Prevention, Detection and Suppression (FPDS) project. The first was an existing vacuum facility, VF-13, located at NASA John Glenn Research Center. This 6350 liter chamber could accommodate fuels sample lengths up to 2 m. However, operational costs and restricted accessibility limited the test program, so a second laboratory scale facility was developed in parallel. By stacking additional two chambers on top of an existing combustion chamber facility, this 81 liter Stacked-chamber facility could accommodate a 1.5 m sample length. The larger volume, more ideal environment of VF-13 was used to obtain baseline data for comparison with the stacked chamber facility. In this way, the stacked chamber facility was intended for long term testing, with VF-13 as the proving ground. Four different solid fuels (adding machine paper, poster paper, PMMA plates, and Nomex fabric) were tested with fuel sample lengths up to 2 m. For thin samples (papers) with widths up to 5 cm, the flame reached a steady state length, which demonstrates that flame length may be stabilized even when the edge effects are reduced. For the thick PMMA plates, flames reached lengths up to 70 cm but were highly energetic and restricted by oxygen depletion. Tests with the Nomex fabric confirmed that the cyclic flame phenomena, observed in small facility tests, continued over longer sample. New

  14. Fuel Quality/Processing Study. Volume II. Appendix, Task I, literature survey

    SciTech Connect

    O'Hara, J B; Bela, A; Jentz, N E; Klumpe, H W; Kessler, R E; Kotzot, H T; Loran, B I

    1981-04-01

    This activity was begun with the assembly of information from Parsons' files and from contacts in the development and commercial fields. A further more extensive literature search was carried out using the Energy Data Base and the American Petroleum Institute Data Base. These are part of the DOE/RECON system. Approximately 6000 references and abstracts were obtained from the EDB search. These were reviewed and the especially pertinent documents, approximately 300, were acquired in the form of paper copy or microfiche. A Fuel Properties form was developed for listing information pertinent to gas turbine liquid fuel properties specifications. Fuel properties data for liquid fuels from selected synfuel processes, deemed to be successful candidates for near future commercial plants were tabulated on the forms. The processes selected consisted of H-Coal, SRC-II and Exxon Donor Solvent (EDS) coal liquefaction processes plus Paraho and Tosco shale oil processes. Fuel properties analyses for crude and distillate syncrude process products are contained in Section 2. Analyses representing synthetic fuels given refinery treatments, mostly bench scale hydrotreating, are contained in Section 3. Section 4 discusses gas turbine fuel specifications based on petroleum source fuels as developed by the major gas turbine manufacturers. Section 5 presents the on-site gas turbine fuel treatments applicable to petroleum base fuels impurities content in order to prevent adverse contaminant effects. Section 7 relates the environmental aspects of gas turbine fuel usage and combustion performance. It appears that the near future stationary industrial gas turbine fuel market will require that some of the synthetic fuels be refined to the point that they resemble petroleum based fuels.

  15. A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

    NASA Astrophysics Data System (ADS)

    Navarro, Jorge

    The goal of this study presented is to determine the best available nondestructive technique necessary to collect validation data as well as to determine burnup and cooling time of the fuel elements on-site at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal, the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements nondestructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed were used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results, it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however, in order to enhance the quality of the spectra collected using this scintillator, a deconvolution method was developed. Following the development of the deconvolution method

  16. A feasibility and optimization study to determine cooling time and burnup of advanced test reactor fuels using a nondestructive technique

    SciTech Connect

    Navarro, Jorge

    2013-12-01

    The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method

  17. [Experimental study on particle size distributions of an engine fueled with blends of biodiesel].

    PubMed

    Lu, Xiao-Ming; Ge, Yun-Shan; Han, Xiu-Kun; Wu, Si-Jin; Zhu, Rong-Fu; He, Chao

    2007-04-01

    The purpose of this study is to obtain the particle size distributions of an engine fueled biodiesel and its blends. A turbocharged DI diesel engine was tested on a dynamometer. A pump of 80 L/min and fiber glass filters with diameter of 90 mm were used to sample engine particles in exhaust pipe. Sampling duration was 10 minutes. Particle size distributions were measured by a laser diffraction particle size analyzer. Results indicated that higher engine speed resulted in smaller particle sizes and narrower distributions. The modes on distribution curves and mode variation were larger with dry samples than with wet samples (dry: around 10 - 12 microm vs. wet: around 4 - 10 microm). At low speed, Sauter mean diameter d32 of dry samples was the biggest with B100, the smallest with diesel fuel, and among them with B20, while at high speed, d32 the biggest with B20, the smallest with B100, and in middle with diesel. Median diameter d(0.5) also reflected the results. Except for 2 000 r/min, d32 of wet with B20 is the biggest, the smallest with diesel, and in middle with B100. The large mode variation resulted in increase of d32. PMID:17639924

  18. Numerical study of changing the geometry of the flow field of a PEM fuel cell

    NASA Astrophysics Data System (ADS)

    Khazaee, I.; Sabadbafan, H.

    2016-05-01

    The geometry of channels of a PEM fuel cell is an important parameter that affects the performance of it that the lower voltage loss in polarization curve can indicate the better performance. In this study a complete three-dimensional and single phase model is used to investigate the effect of increasing the number of serpentine channels in the bipolar plates and also increasing the area (depth) of channels of a PEM fuel cell with rectangular, triangular and elliptical cross-section geometry. A single set of conservation equations which are valid for the flow channels, gas-diffusion electrodes, catalyst layers, and the membrane region is developed and numerically solved using a finite volume based computational fluid dynamics technique. The results show that there are good agreement with the numerical results and experimental results of the previous work of authors. Also the results show that by increasing the number of channels from one to four and eight, the performance improved about 18 % and by decreasing the area of channels from 2 to 1 mm2 the performance improved about 13 %.

  19. Synthesis and characterization of zirconia-magnesia inert matrix fuel: Uranium homolog studies

    SciTech Connect

    Holliday, Kiel; Hartmann, Thomas; Poineau, Frederic; Kennedy, J Rory; Czerwinski, Ken

    2009-10-21

    X-ray powder diffraction, X-ray fluorescence, microscopy, X-ray absorption fine structure, and electron probe microanalysis were used to characterize ZrO2–MgO inert matrix fuel containing UO2 (as a fissile element and a Pu homolog) and Er2O3 as a burnable poison. A large composition range of MgO and ZrO2 was evaluated to determine total concentrations, local environment, phases present, phase mixing, and phase composition. It was found that most compositions of the material consist of two phases: MgO (periclase) and ZrO2 (cubic zirconia). The zirconia phase incorporates up to 5% (wt/wt) MgO and up to 20% and 10% (wt/wt) UO2 and Er2O3 respectively. This allows the fissile material and burnable poison to be incorporated into the zirconia crystal structure and defines the limits of this isomorphic substitution. The bond deformation due to the isomorphic substitution of uranium was determined by X-ray absorption fine structure. The MgO phase remains pure, which will enable design optimization of the overall thermophysical properties of the inert matrix fuel in regard to thermal diffusivity and thermal conductivity. This characterization data will be used in future studies to correlate the dissolution behavior of inert matrix material containing plutonium.

  20. Feasibility study on introduction of the bio-fuel power generation in tropical regions

    NASA Astrophysics Data System (ADS)

    1993-03-01

    Study is made on feasibility of introducing the bio-fuel power generation in tropical regions, especially in South East Asia including Okinawa and South America. Biomass promising as bio-fuel is bagasse and palm oil mill dregs; and bagasse is found to be advantageous to the use for large-scaled power generation. Prospective uses of bagasse are a combined use of gasification process and gas turbine power generation, an effective use of gas turbine exhaust heat at sugar cane factories, and a use of the system to be developed which totalizes these two. As to how to carry out the R and D project, since the gasification power generation process itself is a high technology and has partially unknown fields, it is desirable that research and development are conducted in such technologically developed countries as Japan (Okinawa). A developmental plan, therefore, is worked out as such that a pilot plant of approximately 3000kW is to be constructed in Okinawa because the period for bagasse production is at least 3 months there, and a commercial-scale plant is to be constructed and operated in such big bagasse-producing countries as Brazil.

  1. A spectrophotometric study of cerium IV and chromium VI species in nuclear fuel reprocessing process streams

    NASA Astrophysics Data System (ADS)

    Nickson, I. D.; Boxall, C.; Jackson, A.; Whillock, G. O. H.

    2010-03-01

    Nuclear fuel reprocessing schemes such as PUREX and UREX utilise HNO3 media. An understanding of the corrosion of process engineering materials such as stainless steel in such media is a major concern for the nuclear industry. Two key species are cerium and chromium which, as Ce(IV), Cr(VI), may act as corrosion accelerants. An on-line analytical technique for these quantities would be useful for determining the relationship between corrosion rate and [Ce(IV)] and [Cr(VI)]. Consequently, a strategy for simultaneous quantification of Ce(IV), Cr(VI) and Cr(III) in the presence of other ions found in average burn-up Magnox / PWR fuel reprocessing stream (Fe, Mg, Nd, Al) is being developed. This involves simultaneous UV-vis absorbance measurement at 620, 540, 450 nm, wavelengths where Ce and Cr absorb but other ions do not. Mixed solutions of Cr(VI) and Ce(IV) are found to present higher absorbance values at 540 nm than those predicted from absorbances recorded from single component solutions of those ions. This is attributed to the formation of a 3:1 Cr(VI)-Ce(IV) complex and we report on the complexation and UV-visible spectrophotometric characteristics of this species. To the best of our knowledge this is the first experimental study of this complex in aqueous nitric acid solution systems.

  2. Technetium chemistry in the fuel cycle: combining basic and applied studies.

    PubMed

    Poineau, Frederic; Mausolf, Edward; Jarvinen, Gordon D; Sattelberger, Alfred P; Czerwinski, Kenneth R

    2013-04-01

    Technetium is intimately linked with nuclear reactions. The ultraminute natural levels in the environment are due to the spontaneous fission of uranium isotopes. The discovery of technetium was born from accelerator reactions, and its use and presence in the modern world are directly due to nuclear reactors. While occupying a central location in the periodic table, the chemistry of technetium is poorly explored, especially when compared to its neighboring elements, i.e., molybdenum, ruthenium, and rhenium. This state of affairs, which is tied to the small number of laboratories equipped to work with the long-lived (99)Tc isotope, provides a remarkable opportunity to combine basic studies with applications for the nuclear fuel cycle. An example is given through examination of the technetium halide compounds. Binary metal halides represent some of the most fundamental of inorganic compounds. The synthesis of new technetium halides demonstrates trends with structure, coordination number, and speciation that can be utilized in the nuclear fuel cycle. Examples are provided for technetium-zirconium alloys as waste forms and the formation of reduced technetium species in separations. PMID:23153109

  3. Technetium chemistry in the fuel cycle: combining basic and applied studies.

    PubMed

    Poineau, Frederic; Mausolf, Edward; Jarvinen, Gordon D; Sattelberger, Alfred P; Czerwinski, Kenneth R

    2013-04-01

    Technetium is intimately linked with nuclear reactions. The ultraminute natural levels in the environment are due to the spontaneous fission of uranium isotopes. The discovery of technetium was born from accelerator reactions, and its use and presence in the modern world are directly due to nuclear reactors. While occupying a central location in the periodic table, the chemistry of technetium is poorly explored, especially when compared to its neighboring elements, i.e., molybdenum, ruthenium, and rhenium. This state of affairs, which is tied to the small number of laboratories equipped to work with the long-lived (99)Tc isotope, provides a remarkable opportunity to combine basic studies with applications for the nuclear fuel cycle. An example is given through examination of the technetium halide compounds. Binary metal halides represent some of the most fundamental of inorganic compounds. The synthesis of new technetium halides demonstrates trends with structure, coordination number, and speciation that can be utilized in the nuclear fuel cycle. Examples are provided for technetium-zirconium alloys as waste forms and the formation of reduced technetium species in separations.

  4. SOLID FUEL USE IS A MAJOR RISK FACTOR FOR ACUTE CORONARY SYNDROMES AMONG RURAL WOMEN: A MATCHED CASE CONTROL STUDY

    PubMed Central

    Fatmi, Z.; Coggon, D.; Kazi, A.; Naeem, I.; Azam, I.; Kadir, M.M.; Sathiakumar, N.

    2014-01-01

    Objectives Almost half of the world’s population uses solid fuel for cooking, exposing women to high levels of particulate pollution in indoor air. We assessed the risk of acute coronary syndrome (ACS) among rural women, according to their use of solid fuel. Study design Matched case control study. Methods Data were collected at a public tertiary care hospital in a rural district of Pakistan. Seventy-three women with ACS were compared with controls, individually matched for sex and age (±5years), who were admitted to hospital for other reasons. Fuels used for cooking and exposures to potentially confounding variables were ascertained through a questionnaire administered at interview and measurement of height and weight. Conditional logistic regression was used to estimate odds ratios (ORs) with 95% confidence intervals (95% CIs). Results After adjustment for potential confounding factors, current use of solid fuel was strongly associated with ACS ( OR 4.8, 95% CI: 1.5 to 14.8), and risk was lowest in women who had last used solid fuel more than 15 years earlier. The population attributable fraction for ACS in relation to current use of solid fuel was 49.0% (95% CI: 41.3% - 57.4%). Conclusions These findings support the hypothesis that indoor air pollution from use of solid fuel is an important cause of ACS. Our study demonstrates the feasibility of case-control studies in rural populations of women to address this question, and is an encouragement to larger and statistically more powerful investigations. PMID:24342134

  5. Preliminary design study of small long life boiling water reactor (BWR) with tight lattice thorium nitride fuel

    NASA Astrophysics Data System (ADS)

    Trianti, Nuri; Su'ud, Zaki; Arif, Idam; Riyana, EkaSapta

    2014-09-01

    Neutronic performance of small long-life boiling water reactors (BWR) with thorium nitride based fuel has been performed. A recent study conducted on BWR in tight lattice environments (with a lower moderator percentage) produces small power reactor which has some specifications, i.e. 10 years operation time, power density of 19.1 watt/cc and maximum excess reactivity of about 4%. This excess reactivity value is smaller than standard reactivity of conventional BWR. The use of hexagonal geometry on the fuel cell of BWR provides a substantial effect on the criticality of the reactor to obtain a longer operating time. Supported by a tight concept lattice where the volume fraction of the fuel is greater than the moderator and fuel, Thorium Nitride give good results for fuel cell design on small long life BWR. The excess reactivity of the reactor can be reduced with the addition of gadolinium as burnable poisons. Therefore the hexagonal tight lattice fuel cell design of small long life BWR that has a criticality more than 20 years of operating time has been obtained.

  6. Preliminary design study of small long life boiling water reactor (BWR) with tight lattice thorium nitride fuel

    SciTech Connect

    Trianti, Nuri E-mail: szaki@fi.itba.c.id; Su'ud, Zaki E-mail: szaki@fi.itba.c.id; Arif, Idam E-mail: szaki@fi.itba.c.id; Riyana, EkaSapta

    2014-09-30

    Neutronic performance of small long-life boiling water reactors (BWR) with thorium nitride based fuel has been performed. A recent study conducted on BWR in tight lattice environments (with a lower moderator percentage) produces small power reactor which has some specifications, i.e. 10 years operation time, power density of 19.1 watt/cc and maximum excess reactivity of about 4%. This excess reactivity value is smaller than standard reactivity of conventional BWR. The use of hexagonal geometry on the fuel cell of BWR provides a substantial effect on the criticality of the reactor to obtain a longer operating time. Supported by a tight concept lattice where the volume fraction of the fuel is greater than the moderator and fuel, Thorium Nitride give good results for fuel cell design on small long life BWR. The excess reactivity of the reactor can be reduced with the addition of gadolinium as burnable poisons. Therefore the hexagonal tight lattice fuel cell design of small long life BWR that has a criticality more than 20 years of operating time has been obtained.

  7. Fundamental Studies of the Durability of Materials for Interconnects in Solid Oxide Fuel Cells

    SciTech Connect

    Frederick S. Pettit; Gerald H. Meier

    2006-06-30

    Ferritic stainless steels are a leading candidate material for use as an SOFC interconnect, but have the problem of forming volatile chromia species that lead to cathode poisoning. This project has focused both on optimization of ferritic alloys for SOFC applications and evaluating the possibility of using alternative materials. The initial efforts involved studying the oxidation behavior of a variety of chromia-forming ferritic stainless steels in the temperature range 700-900 C in atmospheres relevant to solid oxide fuel cell operation. The alloys exhibited a wide variety of oxidation behavior based on composition. A method for reducing the vaporization is to add alloying elements that lead to the formation of a thermally grown oxide layer over the protective chromia. Several commercial steels form manganese chromate on the surface. This same approach, combined with observations of TiO{sub 2} overlayer formation on the chromia forming, Ni-based superalloy IN 738, has resulted in the development of a series of Fe-22 Cr-X Ti alloys (X=0-4 wt%). Oxidation testing has indicated that this approach results in significant reduction in chromia evaporation. Unfortunately, the Ti also results in accelerated chromia scale growth. Fundamental thermo-mechanical aspects of the durability of solid oxide fuel cell (SOFC) interconnect alloys have also been investigated. A key failure mechanism for interconnects is the spallation of the chromia scale that forms on the alloy, as it is exposed to fuel cell environments. Indentation testing methods to measure the critical energy release rate (Gc) associated with the spallation of chromia scale/alloy systems have been evaluated. This approach has been used to evaluate the thermomechanical stability of chromia films as a function of oxidation exposure. The oxidation of pure nickel in SOFC environments was evaluated using thermogravimetric analysis (TGA) to determine the NiO scaling kinetics and a four-point probe was used to measure

  8. Transport in fuel cells: Electrochemical impedance spectroscopy and neutron imaging studies

    NASA Astrophysics Data System (ADS)

    Aaron, Douglas Scott

    This dissertation focuses on two powerful methods of performing in-situ studies of transport limitations in fuel cells. The first is electrochemical impedance spectroscopy (EIS) while the second is neutron imaging. Three fuel cell systems are studied in this work: polymer electrolyte membrane fuel cells (PEMFCs), microbial fuel cells (MFCs) and enzyme fuel cells (EFCs). The first experimental section of this dissertation focuses on application of EIS and neutron imaging to an operating PEMFC. The effects of cathode-side humidity and flow rate, as well as cell temperature and a transient response to cathode-side humidity, were studied for a PEMFC via EIS. It was found that increased air humidity in the cathode resulted in greatly reduced cathode resistance as well as a significant reduction in membrane resistance. The anode resistance was only slightly reduced in this case. Increased air flow rate was observed to have little effect on any resistance in the PEMFC, though slight reductions in both the anode and the cathode were observed. Increased cell temperature resulted in decreased cathode and anode resistances. Finally, the transient response to increased humidity exhibited unstable behavior for both the anode and the cathode resistances and the PEMFC power output. Neutron imaging allowed the calculation of water content throughout the PEMFC, showing a maximum in water content at the cathode gas diffusion layer - membrane interface. The second experimental section of this dissertation delves into the world of microbial fuel cells. Multiple long-term observations of changes in internal resistances were performed and illustrated the reduction in anode resistance as the bacterial community was established. Over this same time period, the cathode resistance was observed to have increased; these two phenomena suggest that the anode improved over time while the cathode suffered from degradation. Increased anode fluid ionic strength and flow rate both led to significant

  9. Examining the relative effects of fire weather, suppression and fuel treatment on fire behaviour--a simulation study.

    PubMed

    Penman, T D; Collins, L; Price, O F; Bradstock, R A; Metcalf, S; Chong, D M O

    2013-12-15

    Large budgets are spent on both suppression and fuel treatments in order to reduce the risk of wildfires. There is little evidence regarding the relative contribution of fire weather, suppression and fuel treatments in determining the risk posed from wildfires. Here we undertake a simulation study in the Sydney Basin, Australia, to examine this question using a fire behaviour model (Phoenix Rapidfire). Results of the study indicate that fire behaviour is most strongly influenced by fire weather. Suppression has a greater influence on whether a fire reaches 5 ha in size compared to fuel treatments. In contrast, fuel treatments have a stronger effect on the fire size and maximum distance the fire travels. The study suggests that fire management agencies will receive additional benefits from fuel treatment if they are located in areas which suppression resources can respond rapidly and attempt to contain the fires. No combination of treatments contained all fires, and the proportion of uncontained fires increased under more severe fire weather when the greatest number of properties are lost. Our study highlights the importance of alternative management strategies to reduce the risk of property loss.

  10. Application of neural network in the study of combustion rate of natural gas/diesel dual fuel engine.

    PubMed

    Yan, Zhao-Da; Zhou, Chong-Guang; Su, Shi-Chuan; Liu, Zhen-Tao; Wang, Xi-Zhen

    2003-01-01

    In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine.

  11. La2O3 Nano powders by mixture of fuels approach through chemical combustion for dielectric studies

    NASA Astrophysics Data System (ADS)

    Nithesh Sharma, G.; Venkateswara Rao, K.; Sesha Sai Kumar, V.; Shilpa Chakra, Ch; Rajendar, V.; Ranjith Reddy, P.

    2015-02-01

    La2O3 which is considered as a promising substitute for present SiO2 Gate oxide material in CMOS devices has been synthesized by mixture of fuel method . The method involves the mixing of the Lanthanum Nitrate with, mixture 1:1 of Urea and Glycine. The fuel to oxidizer ratio (Ψ) has been maintained as 1.25. The powders were studied by several physical characterization techniques such as X-ray diffraction (XRD), Thermo gravimetric analysis (TGA) and Differential Thermal analysis (DTA) and dielectric properties have been studied using LCR meter. Surface morphology has been studied by SEM. Particle size has been analysed using Particle analyzer.

  12. Kinetic studies and performance evaluation of an anaerobic fixed-film reactor treating fuel alcohol wastewater

    SciTech Connect

    Gonzalez, R.A.

    1987-01-01

    This study was part of an extensive treatability study of the fuel alcohol wastewater generated at the OSU Agricultural Engineering Fuel Alcohol Research Facility. A bench-scale fixed-film upflow anaerobic reactor was operated for a period of over two years in order to collect the appropriate data for reliable design and operation of a full-scale fixed film anaerobic system. The biological kinetic constants for substrate removal, total gas production, and methane production were developed in terms of BOD{sub 5}, COD, and TOC, at two different temperatures, 36C and 25C. Shock loads studies were also performed, including organic shock loads, low temperature shocks, and shut-down (no feeding) periods. The alcohol wastewater can be easily treated using fixed-film upflow anaerobic reactor. The substrate removal characteristics were a function of the applied mass substrate loading. For applied mass substrate loading rates higher than 27 lbs BOD{sub 5} per day per 1000 sq. ft., the treatment efficiency and the gas production deteriorated, mainly due to accumulation of volatile fatty acids. The methane content of the gas decreased and the carbon dioxide content increased as the applied mass loading rates were increased up to around 12 lbs BOD{sub 5}/day/1000 sq. ft. at which point they leveled out 59% and 39%, respectively. The total gas production and the methane production were also a function of the applied mass substrate loading rate. The substrate removal kinetics and the gas kinetics were considerably different at the two temperatures. The reactor was able to successfully accommodate organic and low temperature shock loads, as well as, shut-down or no feeding periods.

  13. Applications study of advanced power generation systems utilizing coal-derived fuels, volume 2

    NASA Astrophysics Data System (ADS)

    Robson, F. L.

    1981-03-01

    Technology readiness and development trends are discussed for three advanced power generation systems: combined cycle gas turbine, fuel cells, and magnetohydrodynamics. Power plants using these technologies are described and their performance either utilizing a medium-Btu coal derived fuel supplied by pipeline from a large central coal gasification facility or integrated with a gasification facility for supplying medium-Btu fuel gas is assessed.

  14. Applications study of advanced power generation systems utilizing coal-derived fuels, volume 2

    NASA Technical Reports Server (NTRS)

    Robson, F. L.

    1981-01-01

    Technology readiness and development trends are discussed for three advanced power generation systems: combined cycle gas turbine, fuel cells, and magnetohydrodynamics. Power plants using these technologies are described and their performance either utilizing a medium-Btu coal derived fuel supplied by pipeline from a large central coal gasification facility or integrated with a gasification facility for supplying medium-Btu fuel gas is assessed.

  15. Experimental Study of Nonane and Nonane/Hexanol Fuel Droplet Combustion in Microgravity

    NASA Technical Reports Server (NTRS)

    Avedisian, C. T.; Callahan, B. J.

    1999-01-01

    In this presentation we review experiments carried out on nonane droplets, and a nonane/hexanol droplet, burning in microgravity to promote spherical symmetry. The nonane/hexanol combination was selected for the following reasons: 1) the spherically symmetric burning history of nonane and nonane/hexanol mixtures has not been previously studied; 2) measurements of the burning history of pure nonane droplets in air extend the existing data base of spherical droplet flames of soot-producing fuels which are useful for testing detailed chemical kinetic models of the spherically symmetric droplet burning process; 3) nonane and hexanol have almost identical boiling points so heterogeneous nucleation on a support fiber is unlikely; 4) hexanol does not have a strong propensity for water vapor absorption; 5) hexanol produces less soot than nonane so that mixtures of nonane and hexanol should show an effect of composition on soot formation. The far-field gas was atmospheric pressure air at room temperature. The evolution of droplet diameter was measured using high speed cine photography of spark-ignited droplets within a confined volume in a drop tower. The importance of soot formation during droplet combustion is derived from the fact that soot is the basic component of the particulate emission process that occurs in spray combustion. The complexity of soot formation motivates a one-dimensional transport condition which is advantageous for modeling. Recent numerical studies of droplet combustion have assumed spherical symmetry when incorporating such aspects as detailed chemistry and radiation, though soot formation itself has not yet been included in any droplet combustion modeling effort. If radiation is not important as would be the case for'small' droplets (i.e., droplets with initial diameters less than about ]mm), soot formation can lead to a nonlinear burning process and a time-varying burning rate, (non-linear burning of a non-sooting fuel like methanol is due to

  16. Experimental Study of Fuel Heating at Low Temperatures in a Wing Tank Model, Volume 1

    NASA Technical Reports Server (NTRS)

    Stockemer, F. J.

    1981-01-01

    Scale model fuel heating systems for use with aviation hydrocarbon fuel at low temperatures were investigated. The effectiveness of the heating systems in providing flowability and pumpability at extreme low temperature when some freezing of the fuel would otherwise occur is evaluated. The test tank simulated a section of an outer wing tank, and was chilled on the upper and lower surfaces. Turbine engine lubricating oil was heated, and recirculating fuel transferred the heat. Fuels included: a commercial Jet A; an intermediate freeze point distillate; a higher freeze point distillate blended according to Experimental Referee Broadened Specification guidelines; and a higher freeze point paraffinic distillate used in a preceding investigation. Each fuel was chilled to selected temperature to evaluate unpumpable solid formation (holdup). Tests simulating extreme cold weather flight, without heating, provided baseline fuel holdup data. Heating and recirculating fuel increased bulk temperature significantly; it had a relatively small effect on temperature near the bottom of the tank. Methods which increased penetration of heated fuel into the lower boundary layer improved the capability for reducing holdup.

  17. Studies of jet fuel thermal stability and oxidation using a quartz crystal microbalance and pressure measurements

    SciTech Connect

    Zabarnick, S. . Aerospace Mechanics Div.)

    1994-05-01

    The thermal stability of aircraft jet fuels was measured in real time with a quartz crystal microbalance (QCM) at 140 C. Qualitative data on the oxidation of these fuels was also obtained by monitoring the system pressure during thermal stressing. The system was operated at relatively low oxygen availability (1 atm air) which more closely approximates the oxygen availability of flowing fuel tests and real fuel systems than previous work. The high sensitivity and good reproducibility of the QCM permitted deposition measurements under unaccelerated conditions (i.e., relatively low temperature and oxygen availability). Correlation of oxidation and deposition behavior provided insight into the deposition and oxidation processes.

  18. Oxygen and Fuel Jet Diffusion Flame Studies in Microgravity Motivated by Spacecraft Oxygen Storage Fire Safety

    NASA Technical Reports Server (NTRS)

    Sunderland, P. B.; Yuan, Z.-G.; Krishnan, S. S.; Abshire, J. M.; Gore, J. P.

    2003-01-01

    Owing to the absence of past work involving flames similar to the Mir fire namely oxygen-enhanced, inverse gas-jet diffusion flames in microgravity the objectives of this work are as follows: 1. Observe the effects of enhanced oxygen conditions on laminar jet diffusion flames with ethane fuel. 2. Consider both earth gravity and microgravity. 3. Examine both normal and inverse flames. 4. Compare the measured flame lengths and widths with calibrated predictions of several flame shape models. This study expands on the work of Hwang and Gore which emphasized radiative emissions from oxygen-enhanced inverse flames in earth gravity, and Sunderland et al. which emphasized the shapes of normal and inverse oxygen-enhanced gas-jet diffusion flames in microgravity.

  19. The study of ionization by electron impact of a substance simulating spent nuclear fuel components

    NASA Astrophysics Data System (ADS)

    Antonov, N. N.; Bochkarev, E. I.; Gavrikov, A. V.; Samokhin, A. A.; Smirnov, V. P.

    2015-11-01

    Plasma sources of model substances are necessary to solve problems associated with development of the spent nuclear fuel (SNF) plasma separation method. Lead was chosen to simulate kinetic and dynamic properties of the heavy SNF components. In this paper we present the results of a study of a lead vapor discharge with a lead concentration of 1012-1013 cm-3. Ionization was carried out by an electron beam (with energy of up to 500 eV per electron) inside a centimeter gap between planar electrodes. The discharge was numerically modeled using the hydrodynamic and single-particle approximation. Current-voltage characteristics and single ionization efficiency were obtained as functions of the vapors concentration and thermoelectric current. An ion current of hundreds of microamperes at the ionization efficiency near tenths of a percent was experimentally obtained. These results are in good agreement with our model.

  20. Impedance study of membrane dehydration and compression in proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Le Canut, Jean-Marc; Latham, Ruth; Mérida, Walter; Harrington, David A.

    Electrochemical impedance spectroscopy (EIS) is used to measure drying and rehydration in proton exchange membrane fuel cells running under load. The hysteresis between forward and backward acquisition of polarization curves is shown to be largely due to changes in the membrane resistance. Drying tests are carried out with hydrogen and simulated reformate (hydrogen and carbon dioxide), and quasi-periodic drying and rehydration conditions are studied. The membrane hydration state is clearly linked to the high-frequency arc in the impedance spectrum, which increases in size for dry conditions indicating an increase in membrane resistance. Changes in impedance spectra as external compression is applied to the cell assembly show that EIS can separate membrane and interfacial effects, and that changes in membrane resistance dominate. Reasons for the presence of a capacitance in parallel with the membrane resistance are discussed.

  1. A study of the direct dimethyl ether fuel cell using alkaline anolyte

    NASA Astrophysics Data System (ADS)

    Xu, Kan; Lao, Shao Jiang; Qin, Hai Ying; Liu, Bin Hong; Li, Zhou Peng

    The electrooxidation behavior of dimethyl ether (DME) dissolved in acidic, neutral or alkaline anolyte has been studied. The cyclic voltammetry measurements reveal that DME in alkaline anolyte demonstrates higher electrooxidation reactivity than that in acidic or neutral anolyte. With increasing the NaOH concentration in the anolyte, the electrooxidation reactivity of DME can be further improved. Direct dimethyl ether fuel cells (DDFCs) are assembled by using Nafion membrane as the electrolyte, Pt/C as the cathode catalyst, and Pt-Ru/C as the anode catalyst. It is found that the use of alkaline anolyte can significantly improve the performance of DDFCs. A maximum power density of 60 mW cm -2 has been achieved when operating the DDFC at 80 °C under ambient pressure.

  2. Comparison of two inductive learning methods: A case study in failed fuel identification

    SciTech Connect

    Reifman, J. ); Lee, J.C. . Dept. of Nuclear Engineering)

    1992-01-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  3. Comparison of two inductive learning methods: A case study in failed fuel identification

    SciTech Connect

    Reifman, J.; Lee, J.C.

    1992-05-01

    Two inductive learning methods, the ID3 and Rg algorithms, are studied as a means for systematically and automatically constructing the knowledge base of expert systems. Both inductive learning methods are general-purpose and use information entropy as a discriminatory measure in order to group objects of a common class. ID3 constructs a knowledge base by building decision trees that discriminate objects of a data set as a function of their class. Rg constructs a knowledge base by grouping objects of the same class into patterns or clusters. The two inductive methods are applied to the construction of a knowledge base for failed fuel identification in the Experimental Breeder Reactor II. Through analysis of the knowledge bases generated, the ID3 and Rg algorithms are compared for their knowledge representation, data overfitting, feature space partition, feature selection, and search procedure.

  4. AB INITIO STUDY OF ADVANCED METALLIC NUCLEAR FUELS FOR FAST BREEDER REACTORS

    SciTech Connect

    Landa, A; Soderlind, P; Grabowski, B; Turchi, P A; Ruban, A V; Vitos, L

    2012-04-23

    Density-functional formalism is applied to study the ground state properties of {gamma}-U-Zr and {gamma}-U-Mo solid solutions. Calculated heats of formation are compared with CALPHAD assessments. We discuss how the heat of formation in both alloys correlates with the charge transfer between the alloy components. The decomposition curves for {gamma}-based U-Zr and U-Mo solid solutions are derived from Ising-type Monte Carlo simulations. We explore the idea of stabilization of the {delta}-UZr{sub 2} compound against the {alpha}-Zr (hcp) structure due to increase of Zr d-band occupancy by the addition of U to Zr. We discuss how the specific behavior of the electronic density of states in the vicinity of the Fermi level promotes the stabilization of the U{sub 2}Mo compound. The mechanism of possible Am redistribution in the U-Zr and U-Mo fuels is also discussed.

  5. A study of spin isomer conversion kinetics in supercritical fluid hydrogen for cyrogenic fuel storage technologies

    NASA Astrophysics Data System (ADS)

    Matthews, Manyalibo J.; Petitpas, Guillaume; Aceves, Salvador M.

    2011-08-01

    A detailed kinetic study of para-ortho hydrogen conversion under supercritical conditions using rotational Raman scattering is presented. Isochoric measurements of initially low ortho concentrations over temperatures 32 < T < 280 K and densities 0.014 < ρ < 0.060 g/cm3 were used to derive kinetic rate constants k(ρ, T) by solving an autocatalytic kinetic rate equation. At low ortho concentrations and T < 100 K, k is found to be ˜2× higher than previous results based on thermal conductivity measurements, decreasing weakly with temperature, similar to Wigner's original paramagnetic theory. Accurate modeling of k(ρ, T) is critical in predicting cryogenic hydrogen fuel tank dormancy performance for hydrogen-power vehicles.

  6. Study of CNG/diesel dual fuel engine's emissions by means of RBF neural network.

    PubMed

    Liu, Zhen-tao; Fei, Shao-mei

    2004-08-01

    Great efforts have been made to resolve the serious environmental pollution and inevitable declining of energy resources. A review of Chinese fuel reserves and engine technology showed that compressed natural gas (CNG)/diesel dual fuel engine (DFE) was one of the best solutions for the above problems at present. In order to study and improve the emission performance of CNG/diesel DFE, an emission model for DFE based on radial basis function (RBF) neural network was developed which was a black-box input-output training data model not require priori knowledge. The RBF centers and the connected weights could be selected automatically according to the distribution of the training data in input-output space and the given approximating error. Studies showed that the predicted results accorded well with the experimental data over a large range of operating conditions from low load to high load. The developed emissions model based on the RBF neural network could be used to successfully predict and optimize the emissions performance of DFE. And the effect of the DFEmain performance parameters, such as rotation speed, load, pilot quantity and injection timing, were also predicted by means of this model. In resumé, an emission prediction model for CNG/diesel DFE based on RBF neural network was built for analyzing the effect of the main performance parameters on the CO, NOx, emissions of DFE. The predicted results agreed quite well with the traditional emissions model, which indicated that the model had certain application value, although it still has some limitations, because of its high dependence on the quantity of the experimental sample data.

  7. Impact Response Study on Covering Cap of Aircraft Big-Size Integral Fuel Tank

    NASA Astrophysics Data System (ADS)

    Wang, Fusheng; Jia, Senqing; Wang, Yi; Yue, Zhufeng

    2016-05-01

    In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

  8. Experimental study of soot formation from a diesel fuel surrogate in a shock tube

    SciTech Connect

    Mathieu, Olivier; Djebaili-Chaumeix, Nabiha; Paillard, Claude-Etienne; Douce, Francoise

    2009-08-15

    The soot tendency (soot induction delay time and soot yield) of a diesel fuel surrogate and of the hydrocarbons that constitute this mixture was studied in a heated shock tube. The surrogate is composed of three hydrocarbons representative of major chemical families of diesel fuels (39% n-propylcyclohexane, 28% n-butylbenzene, and 33% 2,2,4,4,6,8,8-heptamethylnonane in mass proportion). Experiments were carried out for highly diluted mixtures in argon; in the case of pyrolysis and at two equivalence ratios: 18 and 5. The pressure range was relatively high (1090-1870 kPa) and the carbon atom concentration was kept constant at around 2 x 10{sup +18} atoms cm{sup -3}. The effects of the nature of the hydrocarbon, the oxygen addition, and the temperature on the soot induction delay time and soot yield were investigated. A second growth stage of the soot volume fraction was observed. The influence of several parameters on the existence and/or on the amplitude of this second growth seems to indicate the chemical nature of this phenomenon. Results for the soot tendency show that the soot induction delay time and soot yield depend strongly on the structure of the hydrocarbon and on the concentration of oxygen. The study of the diesel surrogate shows that the soot inception process does not depend on synergistic effects between hydrocarbons but seems to be initiated by the constituent of the surrogate that produces soot fastest, while other constituents were consumed later during the soot growth. (author)

  9. An XAS experimental approach to study low Pt content electrocatalysts operating in PEM fuel cells.

    PubMed

    Principi, Emiliano; Witkowska, Agnieszka; Dsoke, Sonia; Marassi, Roberto; Di Cicco, Andrea

    2009-11-21

    We present an X-ray absorption spectroscopy (XAS) study of a low Pt content catalyst layer (Pt loading 0.1 mg cm(-2)) operating at the cathode of a proton exchange membrane fuel cell (PEMFC). This catalyst is based on the use of a mesoporous inorganic matrix as a support for the catalyst Pt nanoparticles. Due to the high Pt dilution, in situ measurements of its structural properties by XAS are challenging and suitable experimental strategies must be devised for this purpose. In particular, we show that accurate XAS in situ fluorescence measurements can be obtained using an optimized fuel cell, suitable protocols for alignment of a focused X-ray beam and an appropriate filter for the background signal of the other atomic species contained in the electrodes. Details, advantages and limitations of the XAS technique for in situ measurements are discussed. Analysis of the near-edge XAS and EXAFS (extended X-ray absorption fine structure) data, corroborated by a HRTEM (high-resolution transmission electron microscopy) study, shows that the Pt particles have a local structure compatible with that of bulk Pt (fcc) and coordination numbers match those expected for particles with typical sizes in the 1.5-2.0 nm range. Substantial changes in the oxidation state and in local atomic arrangement of the Pt particles are found for different applied potentials. The catalyst support, containing W atoms, exhibits a partial reduction upon PEMFC activation, thus mimicking the catalyst behavior. This indicates a possible role of the mesoporous matrix in favouring the oxygen reduction reaction (ORR) and stimulates further research on active catalyst supports.

  10. Impact Response Study on Covering Cap of Aircraft Big-Size Integral Fuel Tank

    NASA Astrophysics Data System (ADS)

    Wang, Fusheng; Jia, Senqing; Wang, Yi; Yue, Zhufeng

    2016-10-01

    In order to assess various design concepts and choose a kind of covering cap design scheme which can meet the requirements of airworthiness standard and ensure the safety of fuel tank. Using finite element software ANSYS/LS- DYNA, the impact process of covering cap of aircraft fuel tank by projectile were simulated, in which dynamical characteristics of simple single covering cap and gland double-layer covering cap impacted by titanium alloy projectile and rubber projectile were studied, as well as factor effects on simple single covering cap and gland double-layer covering cap under impact region, impact angle and impact energy were also studied. Though the comparison of critical damage velocity and element deleted number of the covering caps, it shows that the external covering cap has a good protection effect on internal covering cap. The regions close to boundary are vulnerable to appear impact damage with titanium alloy projectile while the regions close to center is vulnerable to occur damage with rubber projectile. Equivalent strain in covering cap is very little when impact angle is less than 15°. Element deleted number in covering cap reaches the maximum when impact angle is between 60°and 65°by titanium alloy projectile. While the bigger the impact angle and the more serious damage of the covering cap will be when rubber projectile impact composite covering cap. The energy needed for occurring damage on external covering cap and internal covering cap is less than and higher than that when single covering cap occur damage, respectively. The energy needed for complete breakdown of double-layer covering cap is much higher than that of single covering cap.

  11. Trawler fuel exhaust and respiratory impairments: a cross-sectional pilot study among Indian fishermen working in informal sectors

    PubMed Central

    Moitra, Subhabrata; Maity, Santi Gopal; Haldar, Prasun; Pandit, Asis Kumar; Sahu, Subhashis

    2015-01-01

    Background: An estimated half a billion people are engaged in fishing related occupations in India. Exposure to adulterated fuel exhaust is common among deep-sea fishermen, yet little is known about the potential impacts on the exposure to health. Objective: The aim of this study was to investigate whether fuel emission exposure was associated with increased respiratory impairments among fishermen who were occupationally exposed to fuel exhaust compared to fisherman occupationally unexposed to fuel exhaust. Methods: This cross-sectional study compared the prevalence of respiratory symptoms and lung function variables between 152 marine-water and 107 fresh water fishermen considering the use of fuel-driven trawlers. Data were obtained from questionnaires and computerized spirometer. Results: Fishermen exposed to trawler fuel exhaust reported more than double the number of respiratory symptoms compared to the unexposed fisherman (86.2 vs. 40.2%). They also had a significantly higher chance experiencing chronic cough (adjusted OR = 3.51, 95% confidence interval (CI) = 2.09–6.35), chronic phlegm (8.61, 4.76–15.97), and wheezing (4.29, 2.55–7.61) symptoms. Finally, there was a significant reduction of the ratio of mid portion of forced expiratory flow rate and forced vital capacity (FEF25–75/FVC) in the exposed fishermen compared to the unexposed (0.84 vs. 0.73 second−1, P = 0.015). Conclusion: Fuel exhaust may negatively impact on the respiratory health of Indian fishermen. More attention and surveillance of occupational health for fishermen in India is needed. PMID:25658672

  12. Fossil fuels -- future fuels

    SciTech Connect

    1998-03-01

    Fossil fuels -- coal, oil, and natural gas -- built America`s historic economic strength. Today, coal supplies more than 55% of the electricity, oil more than 97% of the transportation needs, and natural gas 24% of the primary energy used in the US. Even taking into account increased use of renewable fuels and vastly improved powerplant efficiencies, 90% of national energy needs will still be met by fossil fuels in 2020. If advanced technologies that boost efficiency and environmental performance can be successfully developed and deployed, the US can continue to depend upon its rich resources of fossil fuels.

  13. Study of passive fuel tank inerting systems for ground combat vehicles

    NASA Astrophysics Data System (ADS)

    McCormick, Steven J.; Motzenbecker, Peter F.; Clauson, Michael J.

    1988-09-01

    Many flammable materials are carried aboard combat vehicles, including fuel, hydraulic fluid, and munitions. A fire involving any of these can lead to destruction of the vehicle and injury to the crew. Ground combat vehicles have relied on fire extinguishing systems to protect the vehicles and crew, while aircraft use passive inerting techniques as well as fire extinguishing systems. The apparent disparity between ground combat vehicles and aircraft has caused the U.S. Congress to direct the Secretary of the Army to examine the use of passive, multiple-hit, fuel tank inerting systems in tracked and wheeled vehicles. This report examines passive fuel tank inerting techniques and provides an assessment of their applicability to ground combat vehicles. The extent of the hazard posed by the combat vehicle fuel tanks has been defined. The adequacy of the technology in reducing this hazard is evaluated for each technique considered. The current technology for the suppression of fires in and from vehicle fuel tanks available to and in use by the armed services, other government agencies, the private sector, and foreign armed services has also been examined. Attention was restricted to passive systems (systems which do not require any mechanical or electrical activation) which can suppress multiple occurrences of fire. Both fuel tank fillers and systems which surround the fuel tanks were considered. A review of currently available passive fuel tank inerting technologies has shown that the majority of these techniques are not effective for ground combat vehicles considering the large antiarmor threats. A significant quantity of testing has been conducted which bears this out. An exception to this are fuel tank jackets which show great promise in improving ground combat fire survivability. Futher development work must be done before this approach can be integrated into production vehicles or retrofitted into fielded vehicles. Proper fuel system and vehicle design, in

  14. A study on the expulsion of iodine from spent-fuel solutions

    SciTech Connect

    Sakurai, Tsutomu; Takahashi, Akira; Ishikawa, Niroh

    1995-02-01

    During dissolution of spent nuclear fuels, some radioiodine remains in spent-fuel solutions. Its expulsion to dissolver off-gas is important to minimize iodine escape to the environment. In our current work, the iodine remaining in spent-fuel solutions varied from 0 to 10% after dissolution of spent PWR-fuel specimens (approximately 3 g each). The amount remaining probably was dependent upon the dissolution time required. The cause is ascribable to the increased nitrous acid concentration that results from NOx generated during dissolution. The presence of nitrous acid was confirmed spectrophotometrically in an NO-HNO{sub 3} system at 100{degrees}C. Experiments examining NOx concentration versus the quantity of iodine in a simulated spent-fuel solution indicate that iodine (I{minus}) in spent fuels is subjected to the following three reactions: (1) oxidation into I{sub 2} by nitric acid, (2) oxidation into I{sub 2} by nitrous acid arising from NOx, and (3) formation of colloidal iodine (AgI, PdI{sub 2}), the major iodine species in a spent-fuel solution. Reaction (2) competes with reaction (3) to control the quantity of iodine remaining in solution. The following two-step expulsion process to remove iodine from a spent-fuel solution was derived from these experiments: Step One - Heat spent-fuel solutions without NOx sparging. When aged colloidal iodine is present, an excess amount of iodate should be added to the solution. Step Two - Sparge the fuel solution with NOx while heating. Effect of this new method was confirmed by use of a spent PWR-fuel solution.

  15. Validation study for crediting chlorine in criticality analyses for spent nuclear fuel disposition

    SciTech Connect

    Sobes, Vladimir; Scaglione, John M; Wagner, John C; Dunn, Michael E

    2015-01-01

    Spent nuclear fuel (SNF) management practices in the United States rely on dry storage systems that include both canister- and cask-based systems. The United States Department of Energy Used Fuel Disposition Campaign is examining the feasibility of direct disposal of dual-purpose (storage and transportation) canisters (DPCs) in a geological repository. One of the major technical challenges for direct disposal is the ability to demonstrate the subcriticality of the DPCs loaded with SNF for the repository performance period (e.g., 10,000 years or more) as the DPCs may undergo degradation over time. Specifically, groundwater ingress into the DPC (i.e., flooding) could allow the system to achieve criticality in scenarios where the neutron absorber plates in the DPC basket have degraded. However, as was shown by Banerjee et al., some aqueous species in the groundwater provide noticeable reactivity reduction for these systems. For certain amounts of particular aqueous species (e.g., chlorine, lithium) in the groundwater, subcriticality can be demonstrated even for DPCs with complete degradation of the neutron absorber plates or a degraded fuel basket configuration. It has been demonstrated that chlorine is the leading impurity, as indicated by significant neutron absorption in the water that is available in reasonable quantities for the deep geological repository media under consideration. This paper presents the results of an investigation of the available integral experiments worldwide that could be used to validate DPC disposal criticality evaluations, including credit for chlorine. Due to the small number of applicable critical configurations, validation through traditional trending analysis was not possible. The bias in the eigenvalue of the application systems due only to the chlorine was calculated using TSURFER analysis and found to be on the order of 100 percent mille (1 pcm = 10-5 keff). This study investigated the design of a series of

  16. Validation Study for Crediting Chlorine in Criticality Analyses for US Spent Nuclear Fuel Disposition

    SciTech Connect

    Sobes, Vladimir; Scaglione, John M.; Wagner, John C.; Dunn, Michael E.

    2015-01-01

    Spent nuclear fuel (SNF) management practices in the United States rely on dry storage systems that include both canister- and cask-based systems. The United States Department of Energy Used Fuel Disposition Campaign is examining the feasibility of direct disposal of dual-purpose (storage and transportation) canisters (DPCs) in a geological repository. One of the major technical challenges for direct disposal is the ability to demonstrate the subcriticality of the DPCs loaded with SNF for the repository performance period (e.g., 10,000 years or more) as the DPCs may undergo degradation over time. Specifically, groundwater ingress into the DPC (i.e., flooding) could allow the system to achieve criticality in scenarios where the neutron absorber plates in the DPC basket have degraded. However, as was shown by Banerjee et al., some aqueous species in the groundwater provide noticeable reactivity reduction for these systems. For certain amounts of particular aqueous species (e.g., chlorine, lithium) in the groundwater, subcriticality can be demonstrated even for DPCs with complete degradation of the neutron absorber plates or a degraded fuel basket configuration. It has been demonstrated that chlorine is the leading impurity, as indicated by significant neutron absorption in the water that is available in reasonable quantities for the deep geological repository media under consideration. This paper presents the results of an investigation of the available integral experiments worldwide that could be used to validate DPC disposal criticality evaluations, including credit for chlorine. Due to the small number of applicable critical configurations, validation through traditional trending analysis was not possible. The bias in the eigenvalue of the application systems due only to the chlorine was calculated using TSURFER analysis and found to be on the order of 100 percent mille (1 pcm = 10-5 keff). This study investigated the design of a series of

  17. Preliminary Design Study of Medium Sized Gas Cooled Fast Reactor with Natural Uranium as Fuel Cycle Input

    NASA Astrophysics Data System (ADS)

    Meriyanti, Su'ud, Zaki; Rijal, K.; Zuhair, Ferhat, A.; Sekimoto, H.

    2010-06-01

    In this study a fesibility design study of medium sized (1000 MWt) gas cooled fast reactors which can utilize natural uranium as fuel cycle input has been conducted. Gas Cooled Fast Reactor (GFR) is among six types of Generation IV Nuclear Power Plants. GFR with its hard neuron spectrum is superior for closed fuel cycle, and its ability to be operated in high temperature (850° C) makes various options of utilizations become possible. To obtain the capability of consuming natural uranium as fuel cycle input, modified CANDLE burn-up scheme[1-6] is adopted this GFR system by dividing the core into 10 parts of equal volume axially. Due to the limitation of thermal hydraulic aspects, the average power density of the proposed design is selected about 70 W/cc. As an optimization results, a design of 1000 MWt reactors which can be operated 10 years without refueling and fuel shuffling and just need natural uranium as fuel cycle input is discussed. The average discharge burn-up is about 280 GWd/ton HM. Enough margin for criticallity was obtained for this reactor.

  18. Preliminary Design Study of Medium Sized Gas Cooled Fast Reactor with Natural Uranium as Fuel Cycle Input

    SciTech Connect

    Meriyanti; Su'ud, Zaki; Rijal, K.; Zuhair; Ferhat, A.; Sekimoto, H.

    2010-06-22

    In this study a feasibility design study of medium sized (1000 MWt) gas cooled fast reactors which can utilize natural uranium as fuel cycle input has been conducted. Gas Cooled Fast Reactor (GFR) is among six types of Generation IV Nuclear Power Plants. GFR with its hard neuron spectrum is superior for closed fuel cycle, and its ability to be operated in high temperature (850 deg. C) makes various options of utilizations become possible. To obtain the capability of consuming natural uranium as fuel cycle input, modified CANDLE burn-up scheme[1-6] is adopted this GFR system by dividing the core into 10 parts of equal volume axially. Due to the limitation of thermal hydraulic aspects, the average power density of the proposed design is selected about 70 W/cc. As an optimization results, a design of 1000 MWt reactors which can be operated 10 years without refueling and fuel shuffling and just need natural uranium as fuel cycle input is discussed. The average discharge burn-up is about 280 GWd/ton HM. Enough margin for criticality was obtained for this reactor.

  19. Study of flow channel geometry using current distribution measurement in a high temperature polymer electrolyte membrane fuel cell

    NASA Astrophysics Data System (ADS)

    Lobato, Justo; Cañizares, Pablo; Rodrigo, Manuel A.; Pinar, F. Javier; Úbeda, Diego

    To improve fuel cell design and performance, research studies supported by a wide variety of physical and electrochemical methods have to be carried out. Among the different techniques, current distribution measurement owns the desired feature that can be performed during operation, revealing information about internal phenomena when the fuel cell is working. Moreover, short durability is one of the main problems that is hindering fuel cell wide implementation and it is known to be related to current density heterogeneities over the electrode surface. A good flow channel geometry design can favor a uniform current density profile, hence hypothetically extending fuel cell life. With this, it was thought that a study on the influence of flow channel geometry on the performance of a high temperature polymer electrolyte membrane (PEM) fuel cell using current distribution measurement should be a very solid work to optimize flow field design. Results demonstrate that the 4 step serpentine and pin-type geometries distribute the reactants more effectively, obtaining a relatively flat current density map at higher current densities than parallel or interdigitated ones and yielding maximum powers up to 25% higher when using oxygen as comburent. If air is the oxidant chosen, interdigitated flow channels perform almost as well as serpentine or pin-type due to that the flow conditions are very important for this geometry.

  20. LES and experimental studies of cold and reacting flow in a swirled partially premixed burner with and without fuel modulation

    SciTech Connect

    Sengissen, A.X.; Van Kampen, J.F.; Huls, R.A.; Stoffels, G.G.M.; Kok, J.B.W.; Poinsot, T.J.

    2007-07-15

    In devices where air and fuel are injected separately, combustion processes are influenced by oscillations of the air flow rate but may also be sensitive to fluctuations of the fuel flow rate entering the chamber. This paper describes a joint experimental and numerical study of the mechanisms controlling the response of a swirled complex-geometry combustor burning natural gas and air. The flow is first characterized without combustion and LDV results are compared to large eddy simulation (LES) data. The nonpulsated reacting regime is then studied and characterized in terms of the heat release field. Finally the fuel flow rate is pulsated at several amplitudes and the response of the chamber is analyzed using phase-locked averaging and acoustic analysis. Results show that LES and acoustic analysis predict the flame dynamics in this complex configuration with accuracy when heat losses (radiation and convection) are accounted for. (author)

  1. Alternative fuel trucks case studies: Running refuse haulers on compressed natural gas

    SciTech Connect

    Norton, P.; Kelly, K.

    1996-07-01

    This document details the experience of New York City`s compressed natural gas refuse haulers. These 35 ton vehicles have engines that displace 10 liters and provide 240 horsepower. Fuel economy, range, cost, maintenance, repair issues, and emissions are discussed. Photographs and figures illustrate the attributes of these alternative fuel vehicles.

  2. A study of jet fuel sooting tendency using the threshold sooting index (TSI) model

    SciTech Connect

    Yang, Yi; Boehman, Andre L.; Santoro, Robert J.

    2007-04-15

    Fuel composition can have a significant effect on soot formation during gas turbine combustion. Consequently, this paper contains a comprehensive review of the relationship between fuel hydrocarbon composition and soot formation in gas turbine combustors. Two levels of correlation are identified. First, lumped fuel composition parameters such as hydrogen content and smoke point, which are conventionally used to represent fuel sooting tendency, are correlated with soot formation in practical combustors. Second, detailed fuel hydrocarbon composition is correlated with these lumped parameters. The two-level correlation makes it possible to predict soot formation in practical combustors from basic fuel composition data. Threshold sooting index (TSI), which correlates linearly with the ratio of fuel molecular weight and smoke point in a diffusion flame, is proposed as a new lumped parameter for sooting tendency correlation. It is found that the TSI model correlates excellently with hydrocarbon compositions over a wide range of fuel samples. Also, in predicting soot formation in actual combustors, the TSI model produces the best results overall in comparison with other previously reported correlating parameters, including hydrogen content, smoke point, and composite predictors containing more than one parameter. (author)

  3. Vegetable oils and animal fats for diesel fuels: a systems study

    SciTech Connect

    Lipinsky, E.S.; Kresovich, S.; Wagner, C.K.; Appelbaum, H.R.; McClure, T.A.; Otis, J.L.; Trayser, D.A.

    1982-01-01

    This paper provided some information on the possible use of vegetable oils and animal fats as substitute fuels and as emergency diesel fuels in the United States. This paper is confined to using triglyceride fuels in agricultural, automotive, and highway transportation applications. Satisfactory substitution of petroleum-based diesel fuels with triglyceride-based fuels requires the development of an integrated system for the production, processing, and end use of the new fuels on a basis that is both technically attractive and economically rewarding to all of the elements of the system. The three subsystems, the farms that produce oilseed crops, the production of triglycerides and protein, and the manufacturers of the diesel engines and the owners of the present stock of auto-ignition engines, are discussed. It was concluded that vegetable oils and animal fats have substantial prospects as long-term substitutes for diesel fuels. If special auto-ignition engines were developed to handle vegetable oils, on-farm production and use might succeed. In the absence of such engine development, it is likely that large, centralized facilities to manufacture vegetable oils and their methylesters will be the successful processing route. Vegetable oils are likely to succeed first in geographical areas with benign climates. Vegetable oils and animal fats have limited prospects as diesel fuels for acute emergencies. The high viscosity of vegetable oils and the necessity to make substantial capital investments to obtain oils from oilseeds render the system relatively inflexible. 4 tables. (DP)

  4. WREM--TOODEE2--MOD3. 2d Time-Dependent Fuel Element Study

    SciTech Connect

    Lauben, G.N.

    1992-03-05

    WREM-TOODEE2 is a two dimensional, time-dependent, fuel-element thermal analysis program. Its primary purpose is to evaluate fuel-element thermal response during post-LOCA refill and reflood in a pressurized water reactor (PWR).

  5. Opportunity fuels

    SciTech Connect

    Lutwen, R.C.

    1994-12-31

    Opportunity fuels - fuels that can be converted to other forms of energy at lower cost than standard fossil fuels - are discussed in outline form. The type and source of fuels, types of fuels, combustability, methods of combustion, refinery wastes, petroleum coke, garbage fuels, wood wastes, tires, and economics are discussed.

  6. X-ray absorption and electrochemical studies of direct methanol fuel cell catalysts

    SciTech Connect

    Zurawski, D.J.; Aldykiewicz, A.J. Jr.; Baxter, S.F.; Krumpelt, M.

    1996-12-31

    In order for polymer electrolyte fuel cells to operate directly on methanol instead of hydrogen, a distinct advantage for portable applications, methanol oxidation must be catalyzed effectively in the acidic environment of the cell. Platinum-ruthenium and platinum-ruthenium oxide are generally considered to be the most active catalysts for this purpose. The presence of ruthenium significantly enhances the activity of platinum in these catalysts, for reasons not yet fully understood. We are using X-ray absorption spectroscopy (XAS) and electrochemical techniques to evaluate the mechanisms proposed to account for this enhancement in order to further improve the catalyst`s activity. We are considering three enhancement mechanisms. An intermediate in the oxidation of methanol on platinum is carbon monoxide and its oxidation is the rate-determining step in the overall oxidation mechanism. It has been proposed that ruthenium facilitates the removal of carbon monoxide from the platinum surface. First, it has been proposed that ruthenium decreases the strength of the platinum-carbon monoxide bond. Carbon monoxide bonds to the catalyst by interacting with the d-band of platinum, therefore a change in the d-band occupancy of platinum as a result of alloying may influence the bond strength of carbon monoxide. Another proposed enhancement mechanism involves lowering of the potential for the formation of the CO-oxidizing species. Finally, the binary catalysts may have a structure which is more conducive to the methanol dehydrogenation and carbon monoxide reactions. Based on these three proposed enhancement mechanisms, a goal of this study is to correlate catalyst electronic properties, structure, and oxidation state with the performance of proton-exchange membrane (Nafion) direct methanol fuel cells.

  7. Feasibility studies of a fuel cell for cogeneration of homogeneously catalyzed acetaldehyde and electricity from ethanol

    SciTech Connect

    Malhotra, S.; Datta, R.

    1996-10-01

    The development and feasibility of a novel fuel cell for simultaneously generating electricity and homogeneously catalyzed acetaldehyde from ethanol are reported. The fuel cell is based on the supported molten-salt electrocatalysis technique that allows use of homogeneous (liquid-phase) catalysts in fuel cells for the first time. The electrocatalytic reaction combines the chemistry of the Wacker process conventionally used for acetaldehyde production from the partial oxidation of ethylene and that of the Veba-Chemie method. Nafion membranes impregnated with different electrolytic materials were used in the fuel cell as electrolytes to allow operation at reaction temperatures up to 165 C. Results obtained are comparable to those reported in the literature on partial oxidation of ethylene to acetaldehyde in a fuel cell based on conventional heterogeneous electrocatalysts.

  8. Study of molten carbonate fuel cell—microturbine hybrid power cycles

    NASA Astrophysics Data System (ADS)

    Jurado, Francisco

    The interaction realized by fuel cell—microturbine hybrids derive primarily from using the rejected thermal energy and combustion of residual fuel from a fuel cell in driving the gas turbine. This leveraging of thermal energy makes the high temperature molten carbonate fuel cells (MCFCs) ideal candidates for hybrid systems. Use of a recuperator contributes to thermal efficiency by transferring heat from the gas turbine exhaust to the fuel and air used in the system. Traditional control design approaches, consider a fixed operating point in the hope that the resulting controller is robust enough to stabilize the system for different operating conditions. On the other hand, adaptive control incorporates the time-varying dynamical properties of the model (a new value of gas composition) and considers the disturbances acting at the plant (load power variation).

  9. Core design study of a supercritical light water reactor with double row fuel rods

    SciTech Connect

    Zhao, C.; Wu, H.; Cao, L.; Zheng, Y.; Yang, J.; Zhang, Y.

    2012-07-01

    An equilibrium core for supercritical light water reactor has been designed. A novel type of fuel assembly with dual rows of fuel rods between water rods is chosen and optimized to get more uniform assembly power distributions. Stainless steel is used for fuel rod cladding and structural material. Honeycomb structure filled with thermal isolation is introduced to reduce the usage of stainless steel and to keep moderator temperature below the pseudo critical temperature. Water flow scheme with ascending coolant flow in inner regions is carried out to achieve high outlet temperature. In order to enhance coolant outlet temperature, the radial power distributions needs to be as flat as possible through operation cycle. Fuel loading pattern and control rod pattern are optimized to flatten power distribution at inner regions. Axial fuel enrichment is divided into three parts to control axial power peak, which affects maximum cladding surface temperature. (authors)

  10. Compatibility study between U-UO2 cermet fuel and T91 cladding

    NASA Astrophysics Data System (ADS)

    Mishra, Sudhir; Kaity, Santu; Khan, K. B.; Sengupta, Pranesh; Dey, G. K.

    2016-12-01

    Cermet is a new fuel concept for the fast reactor system and is ideally designed to combine beneficial properties of both ceramic and metal. In order to understand fuel clad chemical compatibility, diffusion couples were prepared with U-UO2 cermet fuel and T91 cladding material. These diffusion couples were annealed at 923-1073 K for 1000 h and 1223 K for 50 h, subsequently their microstructures were examined using scanning electron microscope (SEM), X-ray energy dispersive spectroscope (EDS) and electron probe microanalyser (EPMA). It was observed that the interaction between the fuel and constituents of T91 clad was limited to a very small region up to the temperature 993 K and discrete U6(Fe,Cr) and U(Fe,Cr)2 intermetallic phases developed. Eutectic microstructure was observed in the reaction zone at 1223 K. The activation energy for reaction at the fuel clad interface was determined.

  11. A fundamental study of the oxidation behavior of SI primary reference fuels with propionaldehyde and DTBP as an additive

    NASA Astrophysics Data System (ADS)

    Johnson, Rodney

    In an effort to combine the benefits of SI and CI engines, Homogeneous Charge Compression Ignition (HCCI) engines are being developed. HCCI combustion is achieved by controlling the temperature, pressure, and composition of the fuel and air mixture so that autoignition occurs in proper phasing with the piston motion. This control system is fundamentally more challenging than using a spark plug or fuel injector to determine ignition timing as in SI and CI engines, respectively. As a result, this is a technical barrier that must be overcome to make HCCI engines applicable to a wide range of vehicles and viable for high volume production. One way to tailor the autoignition timing is to use small amounts of ignition enhancing additives. In this study, the effect of the addition of DTBP and propionaldehyde on the autoignition behavior of SI primary reference fuels was investigated. The present work was conducted in a new research facility built around a single cylinder Cooperative Fuels Research (CFR) octane rating engine but modified to run in HCCI mode. It focused on the effect of select oxygenated hydrocarbons on hydrocarbon fuel oxidation, specifically, the primary reference fuels n-heptane and iso-octane. This work was conducted under HCCI operating conditions. Previously, the operating parameters for this engine were validated for stable combustion under a wide range of operating parameters such as engine speeds, equivalence ratios, compression ratios and inlet manifold temperature. The stable operating range under these conditions was recorded and used for the present study. The major focus of this study was to examine the effect of the addition of DTBP or propionaldehyde on the oxidation behavior of SI primary reference fuels. Under every test condition the addition of the additives DTBP and propionaldehyde caused a change in fuel oxidation. DTBP always promoted fuel oxidation while propionaldehyde promoted oxidation for lower octane number fuels and delayed

  12. Fuel Cell Airframe Integration Study for Short-Range Aircraft. Volume 1; Aircraft Propulsion and Subsystems Integration Evaluation

    NASA Technical Reports Server (NTRS)

    Gummalla, Mallika; Pandy, Arun; Braun, Robert; Carriere, Thierry; Yamanis, Jean; Vanderspurt, Thomas; Hardin, Larry; Welch, Rick

    2006-01-01

    The objective of this study is to define the functionality and evaluate the propulsion and power system benefits derived from a Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) for a future short range commercial aircraft, and to define the technology gaps to enable such a system. United Technologies Corporation (UTC) Integrated Total Aircraft Power System (ITAPS) methodologies were used to evaluate a baseline aircraft and several SOFC architectures. The technology benefits were captured as reductions of the mission fuel burn, life cycle cost, noise and emissions. As a result of the study, it was recognized that system integration is critical to maximize benefits from the SOFC APU for aircraft application. The mission fuel burn savings for the two SOFC architectures ranged from 4.7 percent for a system with high integration to 6.7 percent for a highly integrated system with certain technological risks. The SOFC APU itself produced zero emissions. The reduction in engine fuel burn achieved with the SOFC systems also resulted in reduced emissions from the engines for both ground operations and in flight. The noise level of the baseline APU with a silencer is 78 dBA, while the SOFC APU produced a lower noise level. It is concluded that a high specific power SOFC system is needed to achieve the benefits identified in this study. Additional areas requiring further development are the processing of the fuel to remove sulfur, either on board or on the ground, and extending the heat sink capability of the fuel to allow greater waste heat recovery, resolve the transient electrical system integration issues, and identification of the impact of the location of the SOFC and its size on the aircraft.

  13. A study of NO{sub x} reduction by fuel injection recirculation. Topical report, January 1995--May 1995

    SciTech Connect

    Turns, S.R.; Feese, J.J.; Frenklach, M.Y.

    1995-07-01

    Flue-gas recirculation (FGR) is a well-known method used to control oxides of nitrogen (NO{sub x}) in industrial burner applications. Recent small- and large-scale experiments by Carnot (Tustin, CA) have shown that introducing the recirculated flue gases with the fuel results in a much greater reduction in NO{sub x}, per unit mass of gas recirculated, in comparison to introducing the flue gases with the combustion air. That fuel injection recirculation (FIR) is more effective than windbox FGR is quite remarkable. At present, however, there is no definitive understanding of why FIR is more effective than conventional FGR. One speculation is that introducing the diluent gases on the fuel side of the flame affects the prompt-NO mechanism causing the greater effectiveness. The objective of our research is to ascertain whether or not chemical and/or molecular transport effects alone can explain the differences in NO{sub x} reduction observed between FIR and FGR. This knowledge will aid in the rational application and optimization of FIR in a wide variety of industrial applications. A combined modeling and experimental program is in progress to achieve the research objectives. This report discusses computer modeling studies of counterflow diffusion flames employing detailed chemical kinetics for fuel (hydrogen or methane) combustion and NO{sub x} formation. These simulations allow the calculation of NO{sub x} emission indices for a wide range of conditions. Parametric studies were conducted in which the diluent was added either on the fuel or air side of the flame for a wide range of flow conditions. Preliminary results from these simulation studies indicate that a major factor in FIR effectiveness is the differential effect on flame zone residence times associated with fuel-side versus air-side dilution.

  14. Geometry-controlled triple phase boundary study for low-temperature solid oxide fuel cells reaction kinetics.

    PubMed

    Kim, Young-Beom

    2013-12-01

    In this work, the triple phase boundary (TPB) characteristics of the platinum (Pt)/yttria-stabilized zirconia (YSZ) interface in low-temperature solid oxide fuel cells (LT-SOFCs) was examined through the development of a novel nano electrode fabrication method utilizing nanosphere lithography and Langmuir-Blodgett methods. Dense Pt cathode structures with close-packed circular openings about 300 to 600 nm in diameter were successfully fabricated on 300 microm-thick single crystalline YSZ substrates, through which the underlying YSZ surface was exposed to the gas phase. Fuel cell current-voltage behavior and electrochemical impedance spectroscopy (EIS) measurements were carried out in the temperature range of 300-450 degrees C. The fuel cell performance, as evaluated by the peak power density, confirmed that the TPB is the actual electrochemical reaction site, as a proportional relationship was observed between the peak power density and an increase in the TPB density. In addition, electrochemical studies on the cathode interface resistance with different TPB geometries enabled a qualitative estimation of the electrochemically active region or the TPB width for the fuel cell charge transfer reaction. The fabrication and experiment methods employed in this work provide an opportunity to investigate electrode/electrolyte interface characteristics under real fuel cell operating conditions.

  15. A Thrust and Impulse Study of Guanidinium Azo-Tetrazolate as an Additive for Hybrid Rocket Fuel

    NASA Astrophysics Data System (ADS)

    Patton, J.; Wright, A. M.; Dunn, L.; Alford, B.

    2000-03-01

    A thrust and impulse study of the hybrid rocket fuel additive Guanidinium Azo-Tetrazolate (GAT) was conducted at the University of Arkansas at Little Rock (UALR) Hybrid Rocket Facility. GAT is an organic salt with a high percentage of nitrogen. GAT was mixed with the standard hybrid rocket fuel, Hydroxyl-Terminated Polybutadiene (HTPB), in the concentration of 15%, by mass. The fuel grains with the GAT additive were fired for 4 second runs with the oxygen flows of 0.05, 0.07, 0.09, and 0.12 lbm/sec. For each run average thrust, total impulse, and specific impulse were measured. Average thrust, specific impulse, and total impulse vs. oxygen flow were plotted. Similar data was collected for plain HTPB/PAPI fuels for comparison. GAT was found to increase the thrust output when it was added to the standard hybrid rocket fuel, HTPB. GAT also increased the total impulse during the run. The thrust and total impulse were increased at all flows, but especially at the lower oxygen flow rates. Specific impulse only increased during the lower oxygen flow runs, and decreased slightly for the higher oxygen flow runs.

  16. Study of diffusion bond development in 6061 aluminum and its relationship to future high density fuels fabrication.

    SciTech Connect

    Prokofiev, I.; Wiencek, T.; McGann, D.

    1997-10-07

    Powder metallurgy dispersions of uranium alloys and silicides in an aluminum matrix have been developed by the RERTR program as a new generation of proliferation-resistant fuels. Testing is done with miniplate-type fuel plates to simulate standard fuel with cladding and matrix in plate-type configurations. In order to seal the dispersion fuel plates, a diffusion bond must exist between the aluminum coverplates surrounding the fuel meat. Four different variations in the standard method for roll-bonding 6061 aluminum were studied. They included mechanical cleaning, addition of a getter material, modifications to the standard chemical etching, and welding methods. Aluminum test pieces were subjected to a bend test after each rolling pass. Results, based on 400 samples, indicate that at least a 70% reduction in thickness is required to produce a diffusion bond using the standard rollbonding method versus a 60% reduction using the Type II method in which the assembly was welded 100% and contained open 9mm holes at frame corners.

  17. Experimental study of humidity changes on the performance of an elliptical single four-channel PEM fuel cell

    NASA Astrophysics Data System (ADS)

    Gholizadeh, Mohammad; Ghazikhani, Mohsen; Khazaee, Iman

    2016-04-01

    Humidity and humidification in a proton exchange membrane fuel cells (PEM) can significantly affect the performance of these energy generating devices. Since protons (H+) needs to be accompanied by water molecules to pass from the anode side to the cathode side, the PEM fuel cell membrane should be sufficiently wet. Low or high amount of water in the membrane can interrupt the flow of protons and thus reduce the efficiency of the fuel cell. In this context, several experimental studies and modeling have been carried out on PEM fuel cell and interesting results have been achieved. In this paper, the humidity and flow rate of gas in the anode and cathode are modified to examine its effect on fuel cell performance. The results show that the effect of humidity changing in the anode side is greater than that of the cathode so that at zero humidity of anode and 70 % humidity of the cathode, a maximum current flow of 0.512 A/cm2 for 0.12 V was obtained. However, at 70 % anode humidity and zero cathode humidity, a maximum flow of 0.86 A/cm2 for 0.13 V was obtained.

  18. A comparative study on life cycle analysis of molten carbon fuel cells and diesel engines for marine application

    NASA Astrophysics Data System (ADS)

    Alkaner, Selim; Zhou, Peilin

    The study performed a life cycle assessment (LCA) of a molten carbonate fuel cell (MCFC) plant for marine applications. The results are compared to a benchmark conventional diesel engine (DE) which operates as an auxiliary power generating unit. The LCA includes manufacturing of MCFC and DE, fuel supply, operation and decommissioning stages of the system's life cycle. As a new technology in its very early stages of commercialisation, some detailed data for the FC systems are not available. In order to overcome this problem, a series of scenario analysis has also been performed to evaluate the effect of various factors on the overall impact, such as change in power load factors and effect of recycling credit at the end of life cycle. Environmental benefits from fuel cell operation are maximised with the use of hydrogen as an input fuel. For the manufacturing stage of the life cycle, input material and process energy required for fuel cell stack assemblies and balance-of-plants (BOP) represent a bigger impact than that of conventional benchmark mainly due to special materials used in the stack and the weights of the BOP components. Additionally, recovering valuable materials through re-use or re-cycle will reduce the overall environmental burden of the system over its life cycle.

  19. Numerical study of an internal-reforming solid oxide fuel cell and adsorption chiller co-generation system

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Leong, K. C.

    A study is conducted on a cogeneration system that incorporates a natural gas fed internal-reforming solid oxide fuel cell (IRSOFC) and a zeolite/water adsorption chiller (AC). The main aim is to investigate the performance of this combined system under different operating conditions and design parameters. A mathematical model is developed to simulate the combined system under steady-state conditions. The effects of fuel flow rate, fuel utilization factor, circulation ratio, mass of adsorbent and inlet air temperature on the performance are considered. The results show that the proposed IRSOFC-AC cogeneration system can achieve a total efficiency (combined electrical power and cooling power) of more than 77%. The electrical efficiency is found to decrease as the fuel flow rate increases, while the cooling power increases to a constant value. The total efficiency reaches a maximum value with variation of the fuel utilization factor. Both the circulation ratio and the inlet air temperature exert positive impacts on system efficiency.

  20. Nuclear Fuels.

    ERIC Educational Resources Information Center

    Nash, J. Thomas

    1983-01-01

    Trends in and factors related to the nuclear industry and nuclear fuel production are discussed. Topics addressed include nuclear reactors, survival of the U.S. uranium industry, production costs, budget cuts by the Department of Energy and U.S. Geological survey for resource studies, mining, and research/development activities. (JN)

  1. Laboratory Studies of the Effects of Ambient Conditions, Soot Emissions, and Fuel Properties on Contrail Formation

    NASA Astrophysics Data System (ADS)

    Beyersdorf, A. J.; Anderson, B. E.; Bulzan, D.; Miake-Lye, R. C.; Tacina, K.; Thornhill, K. L.; Winstead, E.; Wong, H.; Ziemba, L. D.

    2010-12-01

    Contrail formation by aircraft can affect the global radiation budget and is the most uncertain component of aviation impacts on climate change. Field campaigns studying contrail formation have given insight into their formation pathways. However in order to improve simulations of contrail production, laboratory studies of the initial processes of contrail formation from aircraft-emitted soot are needed. As part of the Aviation Climate Change Research Initiative (ACCRI), laboratory studies of contrail formation from simulated aircraft emissions were performed at the particulate aerosol laboratory (PAL) at the NASA Glenn Research Center. The facility consists of a controlled soot source connected to a flow-through chamber which can simulate atmospheric conditions at altitudes up to 45,000 ft. Soot was made by a propane-fueled CAST generator and allowed to mix with water vapor and sulfuric acid to simulate aircraft emissions. Optical particle counters were employed at two distances from the nozzle tip that provided number concentration and size distributions of newly formed ice particles. The formation of ice particles is presented for chamber temperatures and pressures simulating altitudes between 15,000 and 40,000 feet. Initial results show the role of soot concentration, soot size, concentration of co-emitted pollutants and ambient conditions in ice particle formation.

  2. Focused Schlieren flow visualization studies of multiple venturi fuel injectors in a high pressure combustor

    NASA Technical Reports Server (NTRS)

    Chun, K. S.; Locke, R. J.; Lee, C. M.; Ratvasky, W. J.

    1994-01-01

    Multiple venturi fuel injectors were used to obtain uniform fuel distributions, better atomization and vaporization in the premixing/prevaporizing section of a lean premixed/prevaporized flame tube combustor. A focused Schlieren system was used to investigate the fuel/air mixing effectiveness of various fuel injection configurations. The Schlieren system was focused to a plane within the flow field of a test section equipped with optical windows. The focused image plane was parallel to the axial direction of the flow and normal to the optical axis. Images from that focused plane, formed by refracted light due to density gradients within the flow field, were filmed with a high-speed movie camera at framing rates of 8,000 frames per second (fps). Three fuel injection concepts were investigated by taking high-speed movies of the mixture flows at various operating conditions. The inlet air temperature was varied from 600 F to 1000 F, and inlet pressures from 80 psia to 150 psia. Jet-A fuel was used typically at an equivalence ratio of 0.5. The intensity variations of the digitized Schlieren images were analytically correlated to spatial density gradients of the mixture flows. Qualitative measurements for degree of mixedness, intensity of mixing, and mixing completion time are shown. Various mixing performance patterns are presented with different configurations of fuel injection points and operating conditions.

  3. Numerical study on operating characteristics of a magnesium-based fuel ramjet

    NASA Astrophysics Data System (ADS)

    Yang, Ya-jing; He, Mao-gang

    2012-10-01

    A two-dimensional axis symmetrical model for multi-phase turbulent combustion simulation has been developed in a magnesium-based fuel ramjet, the stochastic model is applied to track the motion and transportation of discrete phase in the whole flow field in Lagrangian frame. Firstly, the flow field parameters distribution including temperature, velocity, Mg particle burning rate, main components are obtained to describe the basic operating characteristics, and the thermoacoustic oscillation during the combustion process is predicted due to the observed vortex. Then combined with the developed thermodynamic calculation program, the influencing rules of water/fuel ratio and magnesium-based fuel composition ratio on ramjet operating characteristics are analyzed. The results obtained show that the distribution of two water/fuel ratios exerts a direct impact on the temperature fluctuations in combustor, further influences the combustion stability, as for theoretical specific impulse, a maximal value is observed along with the total water/fuel ratio, while the monotonous trends for thermal efficiency and propulsive efficiency are achieved respectively. Moreover, the magnesium-based fuel composition ratio is a dominant factor to influence the operating characteristics, and it is proved that the high-proportion Mg in fuel is beneficial to specific impulse augment through validation of both simulation results and thermodynamic calculation results.

  4. Experimental study on detonation parameters and cellular structures of fuel cloud

    NASA Astrophysics Data System (ADS)

    Xie, Li-Feng; Li, Bin; Zhang, Yu-Lei

    2012-04-01

    In this paper, detonation parameters of fuel cloud, such as propylene oxide (PO), isopropyl nitrate (IPN), hexane, 90# oil and decane were measured in a self-designed and constructed vertical shock tube. Results show that the detonation pressure and velocity of PO increase to a peak value and then decrease smoothly with increasing equivalence ratio. Several nitrate sensitizers were added into PO to make fuel mixtures, and test results indicated that the additives can efficiently enhance detonation velocity and pressure of fuel cloud and one type of additive n-propyl nitrate (NPN) played the best in the improvement. The critical initiation energy that directly initiated detonation of all the test liquid fuel clouds showed a U-shape curve relationship with equivalence ratios. The optimum concentration lies on the rich-fuel side ( ϕ > 1). The critical initiation energy is closely related to molecular structure and volatility of fuels. IPN and PO have similar critical values while that of alkanes are larger. Detonation cell sizes of PO were respectively investigated at 25°C, 35°C and 50°C with smoked foil technique. The cell width shows a U-shape curve relationship with equivalence ratios at all temperatures. The minimal cell width also lies on the rich-fuel side ( ϕ > 1). The cell width of PO vapor is slightly larger than that of PO cloud. Therefore, the detonation reaction of PO at normal temperature is controlled by gas phase reaction.

  5. A Stability Study of Ni/Yttria-Stabilized Zirconia Anode for Direct Ammonia Solid Oxide Fuel Cells.

    PubMed

    Yang, Jun; Molouk, Ahmed Fathi Salem; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2015-12-30

    In recent years, solid oxide fuel cells fueled with ammonia have been attracting intensive attention. In this work, ammonia fuel was supplied to the Ni/yttria-stabilized zirconia (YSZ) cermet anode at 600 and 700 °C, and the change of electrochemical performance and microstructure under the open-circuit state was studied in detail. The influence of ammonia exposure on the microstructure of Ni was also investigated by using Ni/YSZ powder and Ni film deposited on a YSZ disk. The obtained results demonstrated that Ni in the cermet anode was partially nitrided under an ammonia atmosphere, which considerably roughened the Ni surface. Moreover, the destruction of the anode support layer was confirmed for the anode-supported cell upon the temperature cycling test between 600 and 700 °C because of the nitriding phenomenon of Ni, resulting in severe performance degradation.

  6. JAEA Studies on High Burnup Fuel Behaviors during Reactivity-Initiated Accident and Loss-of-Coolant Accident

    SciTech Connect

    Fuketa, Toyoshi; Sugiyama, Tomoyuki; Nagase, Fumihisa; Suzuki, Motoe

    2007-07-01

    The objectives of fuel safety research program at Japan Atomic Energy Agency (JAEA) are; to evaluate adequacy of present safety criteria and safety margins; to provide a database for future regulation on higher burnup UO{sub 2} and MOX fuels, new cladding and pellets; and to provide reasonably mechanistic computer codes for regulatory application. The JAEA program is comprised of reactivity-initiated accident (RIA) studies including pulse-irradiation experiments in the NSRR and cladding mechanical tests, loss-of-coolant accident (LOCA) tests including integral thermal shock test and oxidation rate measurement, development and verification of computer codes FEMAXI-6 and RANNS, and so on. In addition to an overview of the fuel safety research at JAEA, most recent progresses in the RIA and LOCA tests programs and the codes development are described and discussed in the paper. (authors)

  7. Additional Studies of the Criticality Safety of Failed Used Nuclear Fuel

    SciTech Connect

    Marshall, William BJ J; Wagner, John C

    2013-01-01

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for periods potentially greater than 40 years. Extended storage (ES) time and irradiation to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, could result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. Criticality analyses are conducted considering representative UNF designs covering a range of enrichments and burnups in multiple cask systems. Prior work developed a set of failed fuel configuration categories and specific configurations were evaluated to understand trends and quantify the consequences of worst-case potential reconfiguration progressions. These results will be summarized here and indicate that the potential impacts on subcriticality can be rather significant for certain configurations (e.g., >20% keff). It can be concluded that the consequences of credible fuel failure configurations from ES or transportation following ES are manageable (e.g., <5% keff). The current work expands on these efforts and examines some modified scenarios and modified approaches to investigate the effectiveness of some techniques for reducing the calculated increase in keff. The areas included here are more realistic modeling of some assembly types and the effect of reconfiguration of some assemblies in the storage and transportation canister.

  8. Pyroprocessing of oxidized sodium-bonded fast reactor fuel - An experimental study of treatment options for degraded EBR-II fuel

    SciTech Connect

    Hermann, S.D.; Gese, N.J.; Wurth, L.A.

    2013-07-01

    An experimental study was conducted to assess pyrochemical treatment options for degraded EBR-II fuel. As oxidized material, the degraded fuel would need to be converted back to metal to enable electrorefining within an existing electro-metallurgical treatment process. A lithium-based electrolytic reduction process was studied to assess the efficacy of converting oxide materials to metal with a particular focus on the impact of zirconium oxide and sodium oxide on this process. Bench-scale electrolytic reduction experiments were performed in LiCl-Li{sub 2}O at 650 C. degrees with combinations of manganese oxide (used as a surrogate for uranium oxide), zirconium oxide, and sodium oxide. In the absence of zirconium or sodium oxide, the electrolytic reduction of MnO showed nearly complete conversion to metal. The electrolytic reduction of a blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O showed substantial reduction of manganese, but only 8.5% of the zirconium was found in the metal phase. The electrolytic reduction of the same blend of MnO-ZrO{sub 2} in LiCl - 1 wt% Li{sub 2}O - 6.2 wt% Na{sub 2}O showed substantial reduction of manganese, but zirconium reduction was even less at 2.4%. This study concluded that ZrO{sub 2} cannot be substantially reduced to metal in an electrolytic reduction system with LiCl - 1 wt% Li{sub 2}O at 650 C. degrees due to the perceived preferential formation of lithium zirconate. This study also identified a possible interference that sodium oxide may have on the same system by introducing a parasitic and cyclic reaction of dissolved sodium metal between oxidation at the anode and reduction at the cathode. When applied to oxidized sodium-bonded EBR-II fuel (e.g., U-10Zr), the prescribed electrolytic reduction system would not be expected to substantially reduce zirconium oxide, and the accumulation of sodium in the electrolyte could interfere with the reduction of uranium oxide, or at least render it less efficient.

  9. Experimental study of the operating characteristics of premixing-prevaporizing fuel/air mixing passages

    NASA Technical Reports Server (NTRS)

    Rohy, D. A.; Meier, J. G.

    1983-01-01

    Fuel spray and air flow characteristics were determined using nonintrusive (optical) measurement techniques in a fuel preparation duct. A very detailed data set was obtained at high pressures (to 10 atm) and temperatures (to 750 K). The data will be used to calibrate an analytical model which will facilitate the design of a lean premixed prevaporized combustor. This combustor has potential for achieving low pollutant emissions and low levels of flame radiation and pattern factors conductive to improved durability and performance for a variety of fuels.

  10. Lifetime studies in H/sub 2//Br/sub 2/ fuel cells

    SciTech Connect

    Barna, G.G.; Frank, S.N.; Teherani, T.H.; Weedon, L.D.

    1984-09-01

    A fully computerized system has been set up for the life testing of H/sub 2/ electrodes in 48% HBr, and of H/sub 2//Br/sub 2/ fuel cells. Given a fuel cell design with dry H/sub 2/ and no anolyte loop, the prime parameters influencing the operating lifetime are the hydrophobicity of the anode and the electrolyte transport property of the membrane. A systematic optimization of all the parameters has generated fuel cells that have operated for 10,000h at 2 A/in./sup 2/, with no significant degradation.

  11. Recent Studies on Methanol Crossover in Liquid-Feed Direct Methanol Fuel Cells

    NASA Technical Reports Server (NTRS)

    Valdez, T. I.; Narayanan, S. R.

    2000-01-01

    In this work, the effects of methanol crossover and airflow rates on the cathode potential of an operating direct methanol fuel cell are explored. Techniques for quantifying methanol crossover in a fuel cell and for separating the electrical performance of each electrode in a fuel cell are discussed. The effect of methanol concentration on cathode potential has been determined to be significant. The cathode is found to be mass transfer limited when operating on low flow rate air and high concentrations of methanol. Improvements in cathode structure and operation at low methanol concentration have been shown to result in improved cell performance.

  12. DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM ANAEROBIC DIGESTER GAS - PHASE I. CONCEPTUAL DESIGN, PRELIMINARY COST, AND EVALUATION STUDY

    EPA Science Inventory

    The report discusses Phase I (a conceptual design, preliminary cost, and evaluation study) of a program to demonstrate the recovery of energy from waste methane produced by anaerobic digestion of waste water treatment sludge. The fuel cell is being used for this application becau...

  13. Study of neutron physics: conversion of the University of Missouri-Rolla reactor to low-enriched fuel

    SciTech Connect

    Straka, M.; Covington, L.

    1987-01-01

    A detailed study of a fuel conversion (using LEU) has been undertaken for the University of Missouri-Rolla reactor. Results achieved with the available code package have been compared with the measured data whenever possible. The neutronic codes LEOPARD and 2DB-UM provided adequate results in most cases examined.

  14. Study on the present use of energy in cooking with an emphasis on economising fuel/utensil system

    SciTech Connect

    Malathi, D.; Swaminathan, K.R.

    1986-03-01

    The article is based on a study where experiments were conducted to find out quantity of different commercial fuels for cooking with respect to utensils (made of different materials) and time for the cooking operations, and investigates energy requirements of various utensils for cooking under varying cooking media.

  15. Fuel properties of cottonseed oil

    SciTech Connect

    Karaosmanoglu, F.; Tueter, M.; Goellue, E.; Yanmaz, S.; Altintig, E.

    1999-11-01

    The use of vegetable oils as fuel alternatives has an exceptional importance in the field of research. In this study, evaluation possibilities of cottonseed oil have been investigated as an alternative candidate for diesel fuel and fuel oil. The fuel property tests were performed according to standard analysis methods for oil and fuel. An overall evaluation of the results indicates that cottonseed oil can be proposed as a possible green substitute for fuel.

  16. Jet aircraft hydrocarbon fuels technology

    NASA Technical Reports Server (NTRS)

    Longwell, J. P. (Editor)

    1978-01-01

    A broad specification, referee fuel was proposed for research and development. This fuel has a lower, closely specified hydrogen content and higher final boiling point and freezing point than ASTM Jet A. The workshop recommended various priority items for fuel research and development. Key items include prediction of tradeoffs among fuel refining, distribution, and aircraft operating costs; combustor liner temperature and emissions studies; and practical simulator investigations of the effect of high freezing point and low thermal stability fuels on aircraft fuel systems.

  17. Electron spin resonance study of thermal instability reactions in jet fuels

    NASA Technical Reports Server (NTRS)

    Zeldes, H.; Livingston, R.

    1984-01-01

    Free radicals were studied by electron spin resonance (ESR) using model compounds that are representative of constituents of jet fuels. Radical formation was initiated with peroxides and hydroperoxides by using UV photolysis at and near room temperature and thermal initiation at higher temperatures. Both oxygen free and air saturated systems were studied. N-Dodecane was frequently used as a solvent, and a mixture of n-dodecyl radicals was made with a peroxide initiator in n-dodecane (free of oxygen) thermally at 212 C and photolytically at room temperature. Hydrogen abstraction from the 3,4,5 and 6-positions gives radicals that are sufficiently alike that their spectra are essentially superimposed. The radical formed by abstract of hydrogen from the 2-position gives a different spectrum. ESR parameters for these radicals were measured. The radical formed by abstraction of a primary hydrogen was not observed. Similar radicals are formed from n-decane. A variety of exploratory experiments were carried out with systems that give free radical spectra to which was added small amounts of 2,5-dimethylpyrrole.

  18. Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications.

    SciTech Connect

    Swain; Greg M.

    2009-04-13

    The original funding under this project number was awarded for a period 12/1999 until 12/2002 under the project title Diamond and Hydrogenated Carbons for Advanced Batteries and Fuel Cells: Fundamental Studies and Applications. The project was extended until 06/2003 at which time a renewal proposal was awarded for a period 06/2003 until 06/2008 under the project title Metal/Diamond Composite Thin-Film Electrodes: New Carbon Supported Catalytic Electrodes. The work under DE-FG02-01ER15120 was initiated about the time the PI moved his research group from the Department of Chemistry at Utah State University to the Department of Chemistry at Michigan State University. This DOE-funded research was focused on (i) understanding structure-function relationships at boron-doped diamond thin-film electrodes, (ii) understanding metal phase formation on diamond thin films and developing electrochemical approaches for producing highly dispersed electrocatalyst particles (e.g., Pt) of small nominal particle size, (iii) studying the electrochemical activity of the electrocatalytic electrodes for hydrogen oxidation and oxygen reduction and (iv) conducting the initial synthesis of high surface area diamond powders and evaluating their electrical and electrochemical properties when mixed with a Teflon binder.

  19. Studies involving high temperature desulfurization/regeneration reactions of metal oxides for fuel cell development

    NASA Astrophysics Data System (ADS)

    Jalan, V.

    1983-10-01

    A high temperature regenerable desulfurization process capable of reducing the sulfur content in coal gases from 200 pp to 1 ppm was investigated to provide for the integration of a coal gasifier with a molten carbonate fuel cell, which requires that the sulfur content be below 1 ppm. Results obtained with packed-bed and fluidized-bed reactors have demonstrated that a CuO/ZnO mixed oxide sorbent is regenerble and capable of lowering the sulfur content (as H2s and COS) from 200 ppm in simulated hot coal-derived gases to below 1 ppm level at 600 to 650 C. A comprecipitated CuO/ZnO was elected for further study. A structural reorganization mechanism, unique to mixed oxides, was identified: the creation of relatively fine crystallites of the sulfide components (Cu2S and ZnS) to counteract the loss of surface area due to sintering during regeneration. Studies with 9 to 26% water vapor in simulated coal gases show that sulfur levels below 1 ppm can be achieved in the temperature range of 500 to 650 C. The ability of CuO/ZnO to remove COS, CS2 and CH3SH at these conditions was demonstrated. A previously proposed pore-plugging model was further developed with good success for data treatment of both packed-bed and fluidized-bed reactors.

  20. Jet fuel instability mechanisms

    NASA Technical Reports Server (NTRS)

    Daniel, S. R.

    1985-01-01

    The mechanisms of the formation of fuel-insoluble deposits were studied in several real fuels and in a model fuel consisting of tetralin in dodecane solution. The influence of addition to the fuels of small concentrations of various compounds on the quantities of deposits formed and on the formation and disappearance of oxygenated species in solution was assessed. The effect of temperature on deposit formation was also investigated over the range of 308-453 K.

  1. Comparative study on ammonia oxidation over Ni-based cermet anodes for solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Molouk, Ahmed Fathi Salem; Yang, Jun; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2016-02-01

    In the current work, we investigate the performance of solid oxide fuel cells (SOFCs) with Ni‒yttria-stabilized zirconia (Ni-YSZ) and Ni‒gadolinia-dope ceria (Ni-GDC) cermet anodes fueled with H2 or NH3 in terms of the catalytic activity of ammonia decomposition. The cermet of Ni-GDC shows higher catalytic activity for ammonia decomposition than Ni-YSZ. In response to this, the performance of direct NH3-fueled SOFC improved by using Ni-GDC anode. Moreover, we observe further enhancement in the cell performance and the catalytic activity for ammonia decomposition with applying Ni-GDC anode synthesised by the glycine-nitrate combustion process. These results reveal that the high performance of Ni-GDC anode for the direct NH3-fueled SOFC results from its mixed ionic-electronic conductivity as well as high catalytic activity for ammonia decomposition.

  2. A Preliminary Study of Fuel Injection and Compression Ignition as Applied to an Aircraft Engine Cylinder

    NASA Technical Reports Server (NTRS)

    Gardiner, Arthur W

    1927-01-01

    This report summarizes some results obtained with a single cylinder test engine at the Langley Field Laboratory during a preliminary investigation of the problem of applying fuel injection and compression ignition to aircraft engines. For this work a standard Liberty Engine cylinder was fitted with a high compression, 11.4 : 1 compression ratio, piston, and equipped with an airless injection system, including a primary fuel pump, an injection pump, and an automatic injection valve. The results obtained during this investigation have indicated the possibility of applying airless injection and compression ignition to a cylinder of this size, 8-inch bore by 7-inch stroke, when operating at engine speeds as high as 1,850 R. P. M. A minimum specific fuel consumption with diesel engine fuel oil of 0.30 pound per I. HP. Hour was obtained when developing about 16 B. HP. At 1,730 R. P. M.

  3. Atmospheric Photochemistry Studies of Pollutant Emissions from Transportation Vehicles Operating on Alternative Fuels

    SciTech Connect

    Jeffries, H.; Sexton, K.; Yu, J.

    1998-07-01

    This project was undertaken with the goal of improving our ability to predict the changes in urban ozone resulting from the widespread use of alternative fuels in automobiles. This report presents the results in detail.

  4. Small gas turbine combustor study: Fuel injector performance in a transpiration-cooled liner

    NASA Technical Reports Server (NTRS)

    Riddlebaugh, S. M.; Norgren, C. T.

    1985-01-01

    The effect of fuel injection technique on the performance of an advanced reverse flow combustor liner constructed of Lamilloy (a multilaminate transpiration type material) was determined. Performance and emission levels are documented over a range of simulated flight conditions using simplex pressure atomizing, spill return, and splash cone airblast injectors. A parametric evaluation of the effect of increased combustor loading with each of the fuel injector types is obtained.

  5. Small gas turbine combustor study - Fuel injector performance in a transpiration-cooled liner

    NASA Technical Reports Server (NTRS)

    Riddlebaugh, S. M.; Norgren, C. T.

    1985-01-01

    The effect of fuel injection technique on the performance of an advanced reverse flow combustor liner constructed of Lamilloy (a multilaminate transpiration type material) was determined. Performance and emission levels are documented over a range of simulated flight conditions using simplex pressure atomizing, spill return, and splash cone airblast injectors. A parametric evaluation of the effect of increased combustor loading with each of the fuel injector types is obtained.

  6. A study of external fuel vaporization. [for aircraft gas turbine engines

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.; Baker, C. E.

    1981-01-01

    Candidate external vaporizer designs for an aircraft gas turbine engine are evaluated with respect to fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. The selected concept is shown to offer potential gains in engine performance in terms of reduced specific fuel consumption and improved engine thrust/weight ratio. The thrust/weight improvement can be traded against vaporization system weight.

  7. In-home solid fuel use and cardiovascular disease: a cross-sectional analysis of the Shanghai Putuo study

    PubMed Central

    2012-01-01

    Background Although recent research evidence suggests an association between household air pollution from solid fuel use, such as coal or biomass, and cardiovascular events such as hypertension, little epidemiologic data are available concerning such exposure effects on cardiovascular endpoints other than hypertension. We explored the association between in-home solid fuel use and self-reported diagnoses of cardiovascular endpoints, such as hypertension, coronary heart disease (CHD), stroke, and diabetes. Methods We analyzed 14,068 Chinese adults, aged 18 years and older. Odds ratios (OR) and the corresponding 95% confidence intervals (CI) were estimated using logistic regression models for the risk of each outcome after adjusting for potential confounders. Results The use of solid fuel in home was significantly associated with an increased risk for hypertension (OR 1.70, 95% CI 1.40 to 2.07), CHD (OR 2.58, 95% CI 1.53 to 4.32), and diabetes (OR 2.48, 95% CI 1.59 to 3.86), after adjusting for potential confounders. Compared with individuals in the lowest tertile of the duration of solid fuel exposure, those in the highest tertile of the duration of solid fuel exposure had an increased odds of hypertension (OR 1.73, 95% CI 1.45 to 2.06), stroke (OR 1.87, 95% CI 1.03 to 3.38), and diabetes (OR 3.18, 95% CI 2.11 to 4.78). Conclusions Our data suggest that in-home solid fuel exposure maybe associated with increased risk for hypertension, CHD, stroke, and diabetes in the Chinese adult population. Further large-scale longitudinal studies are warranted to confirm these findings. PMID:22455369

  8. An experimental study on usage of plastic oil and B20 algae biodiesel blend as substitute fuel to diesel engine.

    PubMed

    Ramesha, D K; Kumara, G Prema; Lalsaheb; Mohammed, Aamir V T; Mohammad, Haseeb A; Kasma, Mufteeb Ain

    2016-05-01

    Usage of plastics has been ever increasing and now poses a tremendous threat to the environment. Millions of tons of plastics are produced annually worldwide, and the waste products have become a common feature at overflowing bins and landfills. The process of converting waste plastic into value-added fuels finds a feasible solution for recycling of plastics. Thus, two universal problems such as problems of waste plastic management and problems of fuel shortage are being tackled simultaneously. Converting waste plastics into fuel holds great promise for both the environmental and economic scenarios. In order to carry out the study on plastic wastes, the pyrolysis process was used. Pyrolysis runs without oxygen and in high temperature of about 250-300 °C. The fuel obtained from plastics is blended with B20 algae oil, which is a biodiesel obtained from microalgae. For conducting the various experiments, a 10-HP single-cylinder four-stroke direct-injection water-cooled diesel engine is employed. The engine is made to run at 1500 rpm and the load is varied gradually from 0 to 100 %. The performance, emission and combustion characteristics are observed. The BTE was observed to be higher with respect to diesel for plastic-biodiesel blend and biodiesel blend by 15.7 and 12.9 %, respectively, at full load. For plastic-biodiesel blend, the emission of UBHC and CO decreases with a slight increase in NO x as compared to diesel. It reveals that fuel properties are comparable with petroleum products. Also, the process of converting plastic waste to fuel has now turned the problems into an opportunity to make wealth from waste. PMID:26695415

  9. An experimental study on usage of plastic oil and B20 algae biodiesel blend as substitute fuel to diesel engine.

    PubMed

    Ramesha, D K; Kumara, G Prema; Lalsaheb; Mohammed, Aamir V T; Mohammad, Haseeb A; Kasma, Mufteeb Ain

    2016-05-01

    Usage of plastics has been ever increasing and now poses a tremendous threat to the environment. Millions of tons of plastics are produced annually worldwide, and the waste products have become a common feature at overflowing bins and landfills. The process of converting waste plastic into value-added fuels finds a feasible solution for recycling of plastics. Thus, two universal problems such as problems of waste plastic management and problems of fuel shortage are being tackled simultaneously. Converting waste plastics into fuel holds great promise for both the environmental and economic scenarios. In order to carry out the study on plastic wastes, the pyrolysis process was used. Pyrolysis runs without oxygen and in high temperature of about 250-300 °C. The fuel obtained from plastics is blended with B20 algae oil, which is a biodiesel obtained from microalgae. For conducting the various experiments, a 10-HP single-cylinder four-stroke direct-injection water-cooled diesel engine is employed. The engine is made to run at 1500 rpm and the load is varied gradually from 0 to 100 %. The performance, emission and combustion characteristics are observed. The BTE was observed to be higher with respect to diesel for plastic-biodiesel blend and biodiesel blend by 15.7 and 12.9 %, respectively, at full load. For plastic-biodiesel blend, the emission of UBHC and CO decreases with a slight increase in NO x as compared to diesel. It reveals that fuel properties are comparable with petroleum products. Also, the process of converting plastic waste to fuel has now turned the problems into an opportunity to make wealth from waste.

  10. The economical production of alcohol fuels from coal-derived synthesis gas: Case studies, design, and economics

    SciTech Connect

    1995-10-01

    This project is a combination of process simulation and catalyst development aimed at identifying the most economical method for converting coal to syngas to linear higher alcohols to be used as oxygenated fuel additives. There are two tasks. The goal of Task 1 is to discover, study, and evaluate novel heterogeneous catalytic systems for the production of oxygenated fuel enhancers from synthesis gas, and to explore, analytically and on the bench scale, novel reactor and process concepts for use in converting syngas to liquid fuel products. The goal of Task 2 is to simulate, by computer, energy efficient and economically efficient processes for converting coal to energy (fuel alcohols and/or power). The primary focus is to convert syngas to fuel alcohols. This report contains results from Task 2. The first step for Task 2 was to develop computer simulations of alternative coal to syngas to linear higher alcohol processes, to evaluate and compare the economics and energy efficiency of these alternative processes, and to make a preliminary determination as to the most attractive process configuration. A benefit of this approach is that simulations will be debugged and available for use when Task 1 results are available. Seven cases were developed using different gasifier technologies, different methods for altering the H{sub 2}/CO ratio of the syngas to the desired 1.1/1, and with the higher alcohol fuel additives as primary products and as by-products of a power generation facility. Texaco, Shell, and Lurgi gasifier designs were used to test gasifying coal. Steam reforming of natural gas, sour gas shift conversion, or pressure swing adsorption were used to alter the H{sub 2}/CO ratio of the syngas. In addition, a case using only natural gas was prepared to compare coal and natural gas as a source of syngas.

  11. Applications study of advanced power generation systems utilizing coal-derived fuels. Volume 1: Executive summary

    NASA Astrophysics Data System (ADS)

    Robson, F. L.

    1981-03-01

    The technology status of phosphoric acid and molten carbon fuel cells, combined gas and steam turbine cycles, and magnetohydrodynamic energy conversion systems was assessed and the power performance of these systems when operating with medium-Btu fuel gas whether delivered by pipeline to the power plant or in an integrated mode in which the coal gasification process and power system are closely coupled as an overall power plant was evaluated. Commercially available combined-cycle gas turbine systems can reach projected required performance levels for advanced systems using currently available technology. The phosphoric acid fuel cell appears to be the next most likely candidate for commercialization. On pipeline delivery, the systems efficiency ranges from 40.9% for the phosphoric acid fuel cell to 63% for the molten carbonate fuel cell system. The efficiencies of the integrated power plants vary from approximately 39-40% for the combined cycle to 46-47% for the molden carbonate fuel cell systems. Conventional coal-fired steam stations with flue-gas desulfurization have only 33-35% efficiency.

  12. Comparative Study of Hybrid Powertrains on Fuel Saving, Emissions, and Component Energy Loss in HD Trucks

    SciTech Connect

    Gao, Zhiming; Finney, Charles; Daw, Charles; LaClair, Tim J.; Smith, David

    2014-09-30

    We compared parallel and series hybrid powertrains on fuel economy, component energy loss, and emissions control in Class 8 trucks over both city and highway driving. A comprehensive set of component models describing battery energy, engine fuel efficiency, emissions control, and power demand interactions for heavy duty (HD) hybrids has been integrated with parallel and series hybrid Class 8 trucks in order to identify the technical barriers of these hybrid powertrain technologies. The results show that series hybrid is absolutely negative for fuel economy benefit of long-haul trucks due to an efficiency penalty associated with the dual-step conversions of energy (i.e. mechanical to electric to mechanical). The current parallel hybrid technology combined with 50% auxiliary load reduction could elevate 5-7% fuel economy of long-haul trucks, but a profound improvement of long-haul truck fuel economy requires additional innovative technologies for reducing aerodynamic drag and rolling resistance losses. The simulated emissions control indicates that hybrid trucks reduce more CO and HC emissions than conventional trucks. The simulated results further indicate that the catalyzed DPF played an important role in CO oxidations. Limited NH3 emissions could be slipped from the Urea SCR, but the average NH3 emissions are below 20 ppm. Meanwhile our estimations show 1.5-1.9% of equivalent fuel-cost penalty due to urea consumption in the simulated SCR cases.

  13. Applications study of advanced power generation systems utilizing coal-derived fuels. Volume 1: Executive summary

    NASA Technical Reports Server (NTRS)

    Robson, F. L.

    1981-01-01

    The technology status of phosphoric acid and molten carbon fuel cells, combined gas and steam turbine cycles, and magnetohydrodynamic energy conversion systems was assessed and the power performance of these systems when operating with medium-Btu fuel gas whether delivered by pipeline to the power plant or in an integrated mode in which the coal gasification process and power system are closely coupled as an overall power plant was evaluated. Commercially available combined-cycle gas turbine systems can reach projected required performance levels for advanced systems using currently available technology. The phosphoric acid fuel cell appears to be the next most likely candidate for commercialization. On pipeline delivery, the systems efficiency ranges from 40.9% for the phosphoric acid fuel cell to 63% for the molten carbonate fuel cell system. The efficiencies of the integrated power plants vary from approximately 39-40% for the combined cycle to 46-47% for the molden carbonate fuel cell systems. Conventional coal-fired steam stations with flue-gas desulfurization have only 33-35% efficiency.

  14. Final Technical Report for Alternative Fuel Source Study-An Energy Efficient and Environmentally Friendly Approach

    SciTech Connect

    Zee, Ralph; Schindler, Anton; Duke, Steve; Burch, Thom; Bransby, David; Stafford, Don

    2010-08-31

    The objective of this project is to conduct research to determine the feasibility of using alternate fuel sources for the production of cement. Successful completion of this project will also be beneficial to other commercial processes that are highly energy intensive. During this report period, we have completed all the subtasks in the preliminary survey. Literature searches focused on the types of alternative fuels currently used in the cement industry around the world. Information was obtained on the effects of particular alternative fuels on the clinker/cement product and on cement plant emissions. Federal regulations involving use of waste fuels were examined. Information was also obtained about the trace elements likely to be found in alternative fuels, coal, and raw feeds, as well as the effects of various trace elements introduced into system at the feed or fuel stage on the kiln process, the clinker/cement product, and concrete made from the cement. The experimental part of this project involves the feasibility of a variety of alternative materials mainly commercial wastes to substitute for coal in an industrial cement kiln in Lafarge NA and validation of the experimental results with energy conversion consideration.

  15. Comparative Study of Hybrid Powertrains on Fuel Saving, Emissions, and Component Energy Loss in HD Trucks

    DOE PAGES

    Gao, Zhiming; Finney, Charles; Daw, Charles; LaClair, Tim J.; Smith, David

    2014-09-30

    We compared parallel and series hybrid powertrains on fuel economy, component energy loss, and emissions control in Class 8 trucks over both city and highway driving. A comprehensive set of component models describing battery energy, engine fuel efficiency, emissions control, and power demand interactions for heavy duty (HD) hybrids has been integrated with parallel and series hybrid Class 8 trucks in order to identify the technical barriers of these hybrid powertrain technologies. The results show that series hybrid is absolutely negative for fuel economy benefit of long-haul trucks due to an efficiency penalty associated with the dual-step conversions of energymore » (i.e. mechanical to electric to mechanical). The current parallel hybrid technology combined with 50% auxiliary load reduction could elevate 5-7% fuel economy of long-haul trucks, but a profound improvement of long-haul truck fuel economy requires additional innovative technologies for reducing aerodynamic drag and rolling resistance losses. The simulated emissions control indicates that hybrid trucks reduce more CO and HC emissions than conventional trucks. The simulated results further indicate that the catalyzed DPF played an important role in CO oxidations. Limited NH3 emissions could be slipped from the Urea SCR, but the average NH3 emissions are below 20 ppm. Meanwhile our estimations show 1.5-1.9% of equivalent fuel-cost penalty due to urea consumption in the simulated SCR cases.« less

  16. Transportation Fuels Markets, PADD 5

    EIA Publications

    2015-01-01

    This study examines supply, demand, and distribution of transportation fuels in Petroleum Administration for Defense District (PADD) 5, a region that includes the western states of California, Arizona, Nevada, Oregon, Washington, Alaska, and Hawaii. For this study, transportation fuels include gasoline, diesel fuel, and jet fuel.

  17. Automotive Fuel and Exhaust Systems.

    ERIC Educational Resources Information Center

    Irby, James F.; And Others

    Materials are provided for a 14-hour course designed to introduce the automotive mechanic to the basic operations of automotive fuel and exhaust systems incorporated on military vehicles. The four study units cover characteristics of fuels, gasoline fuel system, diesel fuel systems, and exhaust system. Each study unit begins with a general…

  18. Alternative aircraft fuels technology

    NASA Technical Reports Server (NTRS)

    Grobman, J.

    1976-01-01

    NASA is studying the characteristics of future aircraft fuels produced from either petroleum or nonpetroleum sources such as oil shale or coal. These future hydrocarbon based fuels may have chemical and physical properties that are different from present aviation turbine fuels. This research is aimed at determining what those characteristics may be, how present aircraft and engine components and materials would be affected by fuel specification changes, and what changes in both aircraft and engine design would be required to utilize these future fuels without sacrificing performance, reliability, or safety. This fuels technology program was organized to include both in-house and contract research on the synthesis and characterization of fuels, component evaluations of combustors, turbines, and fuel systems, and, eventually, full-scale engine demonstrations. A review of the various elements of the program and significant results obtained so far are presented.

  19. Economics of biomass fuels for electricity production: A case study with crop residues

    NASA Astrophysics Data System (ADS)

    Maung, Thein Aye

    In the United Sates and around the world, electric power plants are among the biggest sources of greenhouse gas emissions which the Intergovernmental Panel on Climate Change argued was the main cause of climate change and global warming. This dissertation explores the factors which may induce electricity producers to use biomass fuels for power generation and thereby mitigate the impact of greenhouse gas emissions. Analyses in this dissertation suggest that there are two important factors which will play a major role in determining the future degree of bioelectricity production: the price of coal and the future price of carbon emissions. Using The Forest and Agricultural Sector Optimization Model--Green House Gas version (FASOMGHG) in a case study examining the competitiveness of crop residues, this dissertation finds that crop residues currently cost much more than coal as an electricity generation feedstock because they have lower heat content and higher production/hauling costs. For them to become cost competitive with coal, the combined costs of production and hauling must be cut by more than half or the coal price needs to rise. In particular, for crop residues to have any role in electricity generation either the price of coal has to increase to about 43 per ton or the carbon equivalent price must rise to about 15 per ton. The simulation results also show that crop residues with higher heat content such as wheat residues will have greater opportunities in bioelectricity production than the residues with lower heat content. In addition, the analysis shows that improvements in crop yield do not have much impact on bioelectricity production. However, the energy recovery efficiency does have significant positive impact on the bioelectricity desirability but again only if the carbon equivalent price rises substantially. The analysis also shows the desirability of cofiring biomass as opposed to 100% replacement because this reduces haling costs and increases the

  20. Modeling studies of water consumption for transportation fuel options: Hawaii, US-48

    NASA Astrophysics Data System (ADS)

    King, C. W.; Webber, M. E.

    2011-12-01

    flow restoration that has already been ordered requires that an additional 18.5 Mgal/d from East Maui streams and 12.5 Mgal/d from West Maui streams not be diverted for irrigation or other uses. Further environmental flow requirements based on a habitat-protective standard enumerated by the Department of Aquatic Resources could be an additional 45 Mgal/d. Thus, it is conceivable that over the next several years a total of 76 Mgal/d, which is 20%-30% of the irrigation water at existing sugarcane farms, could be appropriated away from agriculture on Maui. Many locals have never viewed the large-scale diversion of stream flow for agriculture as legitimate. Now that much of the plantation agriculture in Hawai'i has shut down due to lack of competitive economics, the discussion of the priority for use of 'old' agricultural water is prompting more water to be left in streams. At the same time, Hawai'i has goals for energy sustainability that include producing biofuels. Thus, Maui is a microcosm of the struggle for energy and water sustainability. Brief discussions of other studies on the water needs for transportation fuel options for the continental 48 U.S. states will also be presented.

  1. 78 FR 39781 - Consequence Study of a Beyond-Design-Basis Earthquake Affecting the Spent Fuel Pool for a U.S...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-02

    ... earthquake that occurred off the coast of Japan on March 11, 2011. That earthquake did not result in any... COMMISSION Consequence Study of a Beyond-Design-Basis Earthquake Affecting the Spent Fuel Pool for a U.S... comment, titled Consequence Study of a Beyond- Design-Basis Earthquake Affecting the Spent Fuel Pool for...

  2. Misinformation and misbeliefs in the Tuskegee Study of Untreated Syphilis fuel mistrust in the healthcare system.

    PubMed Central

    White, Robert M.

    2005-01-01

    website) that was used to educate respondents who were not aware of the TSUS at baseline had contradictions, errors and challenges in black history, medical and public health history, and women's studies. The content of what was actually read to respondents was unknown. Proportionally more whites who were not aware of the TSUS but who were read author-selected information about the TSUS believed that a similar study could happen today-a belief and possibly mistrust of medical care that appeared to be induced-compared to whites with prestudy awareness of the TSUS but not read information from the CDC website. Both black groups were not dissimilar from each other. The authors used a survey that measured a race difference in response to a medical event (TSUS) specific to only one racial group (blacks) when there were inclusive examples specific to other groups available. The authors used "Tuskegee" as a single-word sound bite for the TSUS--a misuse that was inappropriate in scientific and research discourse and that may fuel mistrust of medical care. Whether knowledge of the TSUS was a predictor of mistrust of the healthcare system was inconclusive based on the results in the authors' article. The core findings of the article made believing their case difficult. The editorial suggested that bias and misinformation in undertaking, analysis and reporting the study may in itself fuel mistrust in medical care in the community. Because of these challenges, the editorial urged caution with regard to any change in research direction or policy debate based on the results reported in the article. PMID:16334509

  3. Misinformation and misbeliefs in the Tuskegee Study of Untreated Syphilis fuel mistrust in the healthcare system.

    PubMed

    White, Robert M

    2005-11-01

    website) that was used to educate respondents who were not aware of the TSUS at baseline had contradictions, errors and challenges in black history, medical and public health history, and women's studies. The content of what was actually read to respondents was unknown. Proportionally more whites who were not aware of the TSUS but who were read author-selected information about the TSUS believed that a similar study could happen today-a belief and possibly mistrust of medical care that appeared to be induced-compared to whites with prestudy awareness of the TSUS but not read information from the CDC website. Both black groups were not dissimilar from each other. The authors used a survey that measured a race difference in response to a medical event (TSUS) specific to only one racial group (blacks) when there were inclusive examples specific to other groups available. The authors used "Tuskegee" as a single-word sound bite for the TSUS--a misuse that was inappropriate in scientific and research discourse and that may fuel mistrust of medical care. Whether knowledge of the TSUS was a predictor of mistrust of the healthcare system was inconclusive based on the results in the authors' article. The core findings of the article made believing their case difficult. The editorial suggested that bias and misinformation in undertaking, analysis and reporting the study may in itself fuel mistrust in medical care in the community. Because of these challenges, the editorial urged caution with regard to any change in research direction or policy debate based on the results reported in the article.

  4. CARS temperature measurements in the fuel preburner of the Space Shuttle main engine: A feasibility study

    NASA Technical Reports Server (NTRS)

    Beiting, E. J.; Luthe, J. C.

    1983-01-01

    This report discusses the feasibility of making temperature profile measurements in the fuel preburner of the main engine of the space shuttle (SSME) using coherent anti-Stokes Raman spectroscopy (CARS). The principal thrust of the work is to identify problems associated with making CARS measurements in high temperature gas phase hydrogen at very high pressures (approx 400 atmospheres). To this end a theoretical study was made of the characteristics of the CAR spectra of H2 as a function of temperature and pressure and the accuracy with which temperatures can be extracted from this spectra. In addition the experimental problems associated with carrying out these measurements on a SSME at NSTL were identified. A conceptual design of a CARS system suitable for this work is included. Many of the results of the calculations made in this report are plotted as a function of temperature. In the course of presenting these results, it was necessary to decide whether the number of density or the pressure should be treated as a fixed parameter.

  5. Theoretical studies on membranes and non-platinum catalysts for polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Ushiyama, Hiroshi

    2015-12-01

    Mechanism of proton transfer among high-density acid groups in the interface between organic and inorganic materials for polymer electrolyte fuel cells has been theoretically examined. It has been clearly shown that the interactions between the phosphate groups at the surface of the inorganic material, zirconium phosphate (ZrP), and the adsorbed water molecules are relatively large and a strong hydrogen-bond network is generated locally. Because of the strong interactions, water molecules can be attached to ZrP and the O-O distance becomes shorter than that in bulk water systems. Because of the short O-O distances and the delocalized charge of each atom, the activation energy of proton transfer at the ZrP surface decreases and causes high proton conductivity even under conditions of high temperature and low humidity. Based on the above studies, the origin of the high proton conductivity of hybrid electrolytes is also discussed. We will also discuss the mechanism of oxygen reduction reaction on non-platinum catalysts such as Ta3N5.

  6. Theoretical studies on membranes and non-platinum catalysts for polymer electrolyte fuel cells

    SciTech Connect

    Ushiyama, Hiroshi

    2015-12-31

    Mechanism of proton transfer among high-density acid groups in the interface between organic and inorganic materials for polymer electrolyte fuel cells has been theoretically examined. It has been clearly shown that the interactions between the phosphate groups at the surface of the inorganic material, zirconium phosphate (ZrP), and the adsorbed water molecules are relatively large and a strong hydrogen-bond network is generated locally. Because of the strong interactions, water molecules can be attached to ZrP and the O–O distance becomes shorter than that in bulk water systems. Because of the short O–O distances and the delocalized charge of each atom, the activation energy of proton transfer at the ZrP surface decreases and causes high proton conductivity even under conditions of high temperature and low humidity. Based on the above studies, the origin of the high proton conductivity of hybrid electrolytes is also discussed. We will also discuss the mechanism of oxygen reduction reaction on non-platinum catalysts such as Ta{sub 3}N{sub 5}.

  7. Comparative study on power generation of dual-cathode microbial fuel cell according to polarization methods.

    PubMed

    Lee, Kang-yu; Ryu, Wyan-seuk; Cho, Sung-il; Lim, Kyeong-ho

    2015-11-01

    Microbial fuel cells (MFCs) exist in various forms depending on the type of pollutant to be removed and the expected performance. Dual-cathode MFCs, with their simple structure, are capable of removing both organic matter and nitrogen. Moreover, various methods are available for the collection of polarization data, which can be used to calculate the maximum power density, an important factor of MFCs. Many researchers prefer the method of varying the external resistance in a single-cycle due to the short measurement time and high accuracy. This study compared power densities of dual-cathode MFCs in a single-cycle with values calculated over multi-cycles to determine the optimal polarization method. External resistance was varied from high to low and vice versa in the single-cycle, to calculate power density. External resistance was organized in descending order with initial start-up at open circuit voltage (OCV), and then it was organized in descending order again after the initial start-up at 1000 Ω. As a result, power density was underestimated at the anoxic cathode when the external resistance was varied from low to high, and overestimated at the aerobic cathode and anoxic cathode when external resistance at OCV was reduced following initial start-up. In calculating the power densities of dual-cathode MFCs, this paper recommends the method of gradually reducing the external resistance after initial start-up with high external resistance. PMID:26210028

  8. Comparative study on power generation of dual-cathode microbial fuel cell according to polarization methods.

    PubMed

    Lee, Kang-yu; Ryu, Wyan-seuk; Cho, Sung-il; Lim, Kyeong-ho

    2015-11-01

    Microbial fuel cells (MFCs) exist in various forms depending on the type of pollutant to be removed and the expected performance. Dual-cathode MFCs, with their simple structure, are capable of removing both organic matter and nitrogen. Moreover, various methods are available for the collection of polarization data, which can be used to calculate the maximum power density, an important factor of MFCs. Many researchers prefer the method of varying the external resistance in a single-cycle due to the short measurement time and high accuracy. This study compared power densities of dual-cathode MFCs in a single-cycle with values calculated over multi-cycles to determine the optimal polarization method. External resistance was varied from high to low and vice versa in the single-cycle, to calculate power density. External resistance was organized in descending order with initial start-up at open circuit voltage (OCV), and then it was organized in descending order again after the initial start-up at 1000 Ω. As a result, power density was underestimated at the anoxic cathode when the external resistance was varied from low to high, and overestimated at the aerobic cathode and anoxic cathode when external resistance at OCV was reduced following initial start-up. In calculating the power densities of dual-cathode MFCs, this paper recommends the method of gradually reducing the external resistance after initial start-up with high external resistance.

  9. Experimental study of the oxidation of large surrogates for diesel and biodiesel fuels

    SciTech Connect

    Hakka, Mohammed Hichem; Glaude, Pierre-Alexandre; Herbinet, Olivier; Battin-Leclerc, Frederique

    2009-11-15

    The experimental study of the oxidation of two blend surrogates for diesel and biodiesel fuels, n-decane/n-hexadecane and n-decane/methyl palmitate (74/26 mol/mol), has been performed in a jet-stirred reactor over a wide range of temperatures covering both low, and high-temperature regions (550-1100 K), at a residence time of 1.5 s, at quasi atmospheric pressure with high dilution in helium (hydrocarbon inlet mole fraction of 0.002) and at stoichiometric conditions. Numerous reaction products have been identified and quantified. At low and intermediate temperatures (less than 1000 K), the formation of oxygenated species such as cyclic ethers, aldehydes and ketones has been observed for n-decane, n-hexadecane, and methyl palmitate. At higher temperature, the formation of these species was not observed any more, and small amounts of unsaturated species (olefins and unsaturated methyl esters) have been detected. Results obtained with methyl palmitate and n-hexadecane have been compared in order to highlight similarities and differences between large n-alkanes and methyl esters. (author)

  10. Interaction study between MOX fuel and eutectic lead-bismuth coolant

    NASA Astrophysics Data System (ADS)

    Vigier, Jean-François; Popa, Karin; Tyrpekl, Vaclav; Gardeur, Sébastien; Freis, Daniel; Somers, Joseph

    2015-12-01

    In the frame of the MYRRHA reactor project, the interaction between fuel pellets and the reactor coolant is essential for safety evaluations, e.g. in case of a pin breach. Therefore, interaction tests between uranium-plutonium mixed oxide (MOX) pellets and molten lead bismuth eutectic (LBE) have been performed and three parameters were studied, namely the interaction temperature (500 °C and 800 °C), the oxygen content in LBE and the stoichiometry of the MOX (U0.7Pu0.3O2-x and U0.7Pu0.3O2.00). After 50 h of interaction in closed containers, the pellet integrity was preserved in all cases. Whatever the conditions, neither interaction compounds (crystalline or amorphous) nor lead and bismuth diffusion into the surface regions of the MOX pellets has been detected. In most of the conditions, actinide releases into LBE were very limited (in the range of 0.01-0.15 mg), with a homogeneous release of the different actinides present in the MOX. Detected values were significantly higher in the 800 °C and low LBE oxygen content tests for both U0.7Pu0.3O2-x and U0.7Pu0.3O2.00, with 1-2 mg of actinide released in these conditions.

  11. NMR studies of methanol transport in membranes for fuel cell applications.

    SciTech Connect

    Every, H. A.; Zawodzinski, T. A. , Jr.

    2001-01-01

    Characterization of the methanol diffusion process in Nafion 117 was achieved with the use of a modified pulsed field gradient NMR technique. To ensure that the concentration of methanol was constant throughout the entire experiment, the membrane was continually immersed in the methanol solution. When using the standard pulsed field gradient NMR method, the diffusion of the methanol in the membrane is strongly influenced by the diffusion of methanol in solution. Application of a filter gradient suppresses the signal from the methanol in solution, enabling the methanol diffusion in the membrane to be observed unambiguously. Complete suppression of the solution signal was achieved when a 60% filter gradient was employed. Under such circumstances, the coefficient for diffusion of methanol within the membrane was calculated to be 4x10-6cm2s-1, which is similar to the values reported in the literature. Consequently, the use of NMR filter gradient measurements is a valid method for studying the diffusion coefficient of methanol within fuel cell membranes.

  12. Modelling studies to proper size a hydrogen generator for fuel cells

    SciTech Connect

    Maggio, G.; Recupero, V.; Di Leonardo, R.; Lagana, M.

    1996-12-31

    Based upon an extensive survey of literature a mathematical model has been developed to study the temperature profile along the catalytic bed of a reactor for the methane partial oxidation. The model allowed a preliminary design of a 5 Nm{sup 3} syngas/h prototype to be integrated with second generation fuel cells as hydrogen generator (in the framework of the EC-JOU2 contract). This design was based on some target features, including the choice of a GHSV (gas hour space velocity) equal to 80000 h{sup -1}, a catalyst particle size of 1/8inches, a molar air/methane ratio of 2.7 (i.e. O{sub 2}/CH{sub 4}=0.53), a linear velocity in the catalytic bed of about 2 m/sec, and an inert/catalyst ratio 3:1. Starting from this data, the work has been concerned with the identification of the controlling regime (kinetic or diffusional), and then with the estimation of the gas composition and temperature profiles along the reactor. A comparison between experimental and model results has also been accomplished.

  13. REVIEW OF RESULTS FOR THE OECD/NEA PHASE VII BENCHMARK: STUDY OF SPENT FUEL COMPOSITIONS FOR LONG TERM DISPOSAL

    SciTech Connect

    Radulescu, Georgeta; Wagner, John C

    2011-01-01

    This paper summarizes the problem specification and compares participants results for the OECD/NEA/WPNCS Expert Group on Burn-up Credit Criticality Safety Phase VII Benchmark Study of Spent Fuel Compositions for Long-Term Disposal. The Phase VII benchmark was developed to study the ability of relevant computer codes and associated nuclear data to predict spent fuel isotopic compositions and corresponding keff values in a cask configuration over the time duration relevant to spent nuclear fuel (SNF) disposal. The benchmark was divided into two sets of calculations: (1) decay calculations out to 1,000,000 years for provided pressurized-water-reactor (PWR) UO2 discharged fuel compositions and (2) burnup credit criticality calculations for a representative cask model at selected time steps. Contributions from 15 organizations and companies in 10 countries were submitted to the Phase VII benchmark exercise. This paper provides a description of the Phase VII benchmark and detailed comparisons of the participants isotopic compositions and keff values that were calculated with a diversity of computer codes and nuclear data sets. Differences observed in the calculated time-dependent nuclide densities are attributed to different decay data or code-specific numerical approximations. The variability of the keff results is consistent with the evaluated uncertainty associated with cross-section data.

  14. Study on Use of Fuel-Cell Auxiliary Power Units in Refrigerator Cars Employed for Delivery to Convenience Store

    NASA Astrophysics Data System (ADS)

    Katayama, Noboru; Kamiyama, Hideyuki; Kogoshi, Sumio; Kudo, Yusuke; Fukada, Takafumi; Ogawa, Makoto

    The use of fuel-cell auxiliary power units (FC-APU) in refrigerator cars employed delivery to for convenience store delivery has been studied. The delivery pattern is assumed to be a typical pattern that includes driving between convenience stores or between a delivery center and a convenience store, unloading, driver's lunch break. The M15 driving mode, which simulates the driving condition in urban areas, is used as the driving mode in the delivery pattern. The FC-APU system includes a proton-exchange membrane fuel cell (PEFC) module, an inverter, and DC/DC converter. Bench tests of the FC-APU are performed to determine the hydrogen fuel consumption rate and the energy efficiency; these values depend on the output power of the PEFC module. The calculated relationship between the output power and fuel consumption rate of a current used system, which consists of an alternator and a secondary battery, are used to estimate the energy efficiency of the current used system. On the basis of the measurement data in this study and the results for the model proposed by Brodric et al. [C. J. Brodrick et al., Trans. Res. D, vol 7, pp. 303 (2002)], the payback period is calculated. The results indicate that the payback period would be 2.1 years when the FC-APU operates at a load of 70%.

  15. Quantum Mechanics Studies of Fuel Cell Catalysts and Proton Conducting Ceramics with Validation by Experiment

    NASA Astrophysics Data System (ADS)

    Tsai, Ho-Cheng

    We carried out quantum mechanics (QM) studies aimed at improving the performance of hydrogen fuel cells. In part I, The challenge was to find a replacement for the Pt cathode that would lead to improved performance for the Oxygen Reduction Reaction (ORR) while remaining stable under operational conditions and decreasing cost. Our design strategy was to find an alloy with composition Pt3M that would lead to surface segregation such that the top layer would be pure Pt, with the second and subsequent layers richer in M. Under operating conditions we expect the surface to have significant O and/or OH chemisorbed on the surface; we searched for M that would remain segregated under these conditions. Using QM we examined surface segregation for 28 Pt3M alloys, where M is a transition metal. We found that only Pt3Os and Pt3Ir showed significant surface segregation when O and OH are chemisorbed on the catalyst surfaces. This result indicates that Pt3Os and Pt 3Ir favor formation of a Pt-skin surface layer structure that would resist the acidic electrolyte corrosion during fuel cell operation environments. We chose to focus on Os because the phase diagram for Pt-Ir indicated that Pt-Ir could not form a homogeneous alloy at lower temperature. To determine the performance for ORR, we used QM to examine intermediates, reaction pathways, and reaction barriers involved in the processes for which protons from the anode reactions react with O2 to form H2O. These QM calculations used our Poisson-Boltzmann implicit solvation model include the effects of the solvent (water with dielectric constant 78 with pH 7 at 298K). We also carried out similar QM studies followed by experimental validation for the Os/Pt core-shell catalyst fabricated by the underpotential deposition (UPD) method. The QM results indicated that the RDS for ORR is a compromise between the OOH formation step (0.37 eV for Pt, 0.23 eV for Pt2ML/Os core-shell) and H2O formation steps (0.32 eV for Pt, 0.22 eV for Pt2ML

  16. Quantum Mechanics Studies of Fuel Cell Catalysts and Proton Conducting Ceramics with Validation by Experiment

    NASA Astrophysics Data System (ADS)

    Tsai, Ho-Cheng

    We carried out quantum mechanics (QM) studies aimed at improving the performance of hydrogen fuel cells. In part I, The challenge was to find a replacement for the Pt cathode that would lead to improved performance for the Oxygen Reduction Reaction (ORR) while remaining stable under operational conditions and decreasing cost. Our design strategy was to find an alloy with composition Pt3M that would lead to surface segregation such that the top layer would be pure Pt, with the second and subsequent layers richer in M. Under operating conditions we expect the surface to have significant O and/or OH chemisorbed on the surface; we searched for M that would remain segregated under these conditions. Using QM we examined surface segregation for 28 Pt3M alloys, where M is a transition metal. We found that only Pt3Os and Pt3Ir showed significant surface segregation when O and OH are chemisorbed on the catalyst surfaces. This result indicates that Pt3Os and Pt 3Ir favor formation of a Pt-skin surface layer structure that would resist the acidic electrolyte corrosion during fuel cell operation environments. We chose to focus on Os because the phase diagram for Pt-Ir indicated that Pt-Ir could not form a homogeneous alloy at lower temperature. To determine the performance for ORR, we used QM to examine intermediates, reaction pathways, and reaction barriers involved in the processes for which protons from the anode reactions react with O2 to form H2O. These QM calculations used our Poisson-Boltzmann implicit solvation model include the effects of the solvent (water with dielectric constant 78 with pH 7 at 298K). We also carried out similar QM studies followed by experimental validation for the Os/Pt core-shell catalyst fabricated by the underpotential deposition (UPD) method. The QM results indicated that the RDS for ORR is a compromise between the OOH formation step (0.37 eV for Pt, 0.23 eV for Pt2ML/Os core-shell) and H2O formation steps (0.32 eV for Pt, 0.22 eV for Pt2ML

  17. Compatibility Study for Plastic, Elastomeric, and Metallic Fueling Infrastructure Materials Exposed to Aggressive Formulations of Ethanol-blended Gasoline

    SciTech Connect

    Kass, Michael D; Pawel, Steven J; Theiss, Timothy J; Janke, Christopher James

    2012-07-01

    In 2008 Oak Ridge National Laboratory began a series of experiments to evaluate the compatibility of fueling infrastructure materials with intermediate levels of ethanol-blended gasoline. Initially, the focus was elastomers, metals, and sealants, and the test fuels were Fuel C, CE10a, CE17a and CE25a. The results of these studies were published in 2010. Follow-on studies were performed with an emphasis on plastic (thermoplastic and thermoset) materials used in underground storage and dispenser systems. These materials were exposed to test fuels of Fuel C and CE25a. Upon completion of this effort, it was felt that additional compatibility data with higher ethanol blends was needed and another round of experimentation was performed on elastomers, metals, and plastics with CE50a and CE85a test fuels. Compatibility of polymers typically relates to the solubility of the solid polymer with a solvent. It can also mean susceptibility to chemical attack, but the polymers and test fuels evaluated in this study are not considered to be chemically reactive with each other. Solubility in polymers is typically assessed by measuring the volume swell of the polymer exposed to the solvent of interest. Elastomers are a class of polymers that are predominantly used as seals, and most o-ring and seal manufacturers provide compatibility tables of their products with various solvents including ethanol, toluene, and isooctane, which are components of aggressive oxygenated gasoline as described by the Society of Automotive Engineers (SAE) J1681. These tables include a ranking based on the level of volume swell in the elastomer associated with exposure to a particular solvent. Swell is usually accompanied by a decrease in hardness (softening) that also affects performance. For seal applications, shrinkage of the elastomer upon drying is also a critical parameter since a contraction of volume can conceivably enable leakage to occur. Shrinkage is also indicative of the removal of one or more

  18. Study of ceria-carbonate nanocomposite electrolytes for low-temperature solid oxide fuel cells.

    PubMed

    Fan, L; Wang, C; Di, J; Chen, M; Zheng, J; Zhu, B

    2012-06-01

    Composite and nanocomposite samarium doped ceria-carbonates powders were prepared by solid-state reaction, citric acid-nitrate combustion and modified nanocomposite approaches and used as electrolytes for low temperature solid oxide fuel cells. X-ray Diffraction, Scanning Electron Microscope, low-temperature Nitrogen Adsorption/desorption Experiments, Electrochemical Impedance Spectroscopy and fuel cell performance test were employed in characterization of these materials. All powders are nano-size particles with slight aggregation and carbonates are amorphous in composites. Nanocomposite electrolyte exhibits much lower impedance resistance and higher ionic conductivity than those of the other electrolytes at lower temperature. Fuel cell using the electrolyte prepared by modified nanocomposite approach exhibits the best performance in the whole operation temperature range and achieves a maximum power density of 839 mW cm(-2) at 600 degrees C with H2 as fuel. The excellent physical and electrochemical performances of nanocomposite electrolyte make it a promising candidate for low-temperature solid oxide fuel cells.

  19. Humidification factors from laboratory studies of fresh smoke from biomass fuels

    NASA Astrophysics Data System (ADS)

    Day, D. E.; Hand, J. L.; Carrico, C. M.; Engling, Guenter; Malm, W. C.

    2006-11-01

    Measurements of smoke aerosol humidification factors were performed in a laboratory for different biomass fuel types and burn conditions. Two nephelometers simultaneously measured dry and humidified light scattering coefficients (bsp(dry) and bsp(RH), respectively), providing the first observations of the temporal evolution of the humidification factor (f(RH) = bsp(RH)/bsp(dry)) for fresh (minutes-old) smoke. Hygroscopic characteristics of the smoke aerosols varied with fuel type and fire conditions, with the mean f(RH) ranging from 1.01 to 1.95 for fresh minutes-old smoke for the relative humidity (RH) range of 70-94%. These f(RH) values exhibited temporal variability, with some fuels alternating from hygroscopic to nonhygroscopic within minutes. Humidograms were also obtained, demonstrating that smoke from different fuels begins to take up water at different RH values. Humidification factors for hour-old smoke ranged from 1.10 to 1.51 for RH > 90%. Finally, light-absorbing carbon mass measured with a multiwavelength aethalometer demonstrated different spectral responses as a function of fuel type. These laboratory experiments demonstrate the complexity of smoke hygroscopicity from young fires and are essential for understanding the radiative effects of biomass burning in the ambient atmosphere.

  20. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    DOE PAGES

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, suchmore » as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.« less

  1. Thermal compatibility studies of U 3Si 2 dispersion fuels prepared with centrifugally atomized powder

    NASA Astrophysics Data System (ADS)

    Kim, Ki-Hwan; Park, Jong-Man; Kim, Chang-Kyu; Hofman, Gerard L.; Paik, Kyung-Wook

    The interaction between atomized U 3Si 2 and aluminum in dispersion fuel samples has been characterized and compared with that of comminuted U 3Si 2. Fuel samples with atomized powder showed a smaller volume increase compared to those with the comminuted powder, irrespective of heat treatment, and volume fraction of U 3Si 2 powder. The possible reasons for this seem to be as follows: (1) the smaller specific surface area of the atomized spherical powder compared to the irregular comminuted powder translating in a smaller U 3Si 2-Al interface area for the former affecting what appears to be a diffusion-controlled interaction process, (2) the atomized fuel samples also contain lower fraction of as-fabricated porosity than the comminuted fuel samples, which may enhance the restraint force in the swelling fuel meat, (3) the comminuted powder particles have distinctive aluminum penetration paths in the form of deformation zones that originated from the comminution process. There appear to be two pronounced penetration paths of aluminum into atomized U 3Si 2 powder; (1) through the phase interface, leaving a central unreacted island, (2) along grain boundaries, leaving several unreacted islands.

  2. Mechanism reduction for multicomponent surrogates: A case study using toluene reference fuels

    SciTech Connect

    Niemeyer, Kyle E.; Sung, Chih-Jen

    2014-11-01

    Strategies and recommendations for performing skeletal reductions of multicomponent surrogate fuels are presented, through the generation and validation of skeletal mechanisms for a three-component toluene reference fuel. Using the directed relation graph with error propagation and sensitivity analysis method followed by a further unimportant reaction elimination stage, skeletal mechanisms valid over comprehensive and high-temperature ranges of conditions were developed at varying levels of detail. These skeletal mechanisms were generated based on autoignition simulations, and validation using ignition delay predictions showed good agreement with the detailed mechanism in the target range of conditions. When validated using phenomena other than autoignition, such as perfectly stirred reactor and laminar flame propagation, tight error control or more restrictions on the reduction during the sensitivity analysis stage were needed to ensure good agreement. In addition, tight error limits were needed for close prediction of ignition delay when varying the mixture composition away from that used for the reduction. In homogeneous compression-ignition engine simulations, the skeletal mechanisms closely matched the point of ignition and accurately predicted species profiles for lean to stoichiometric conditions. Furthermore, the efficacy of generating a multicomponent skeletal mechanism was compared to combining skeletal mechanisms produced separately for neat fuel components; using the same error limits, the latter resulted in a larger skeletal mechanism size that also lacked important cross reactions between fuel components. Based on the present results, general guidelines for reducing detailed mechanisms for multicomponent fuels are discussed.

  3. Study of effects of fuel properties in turbine-powered business aircraft

    NASA Technical Reports Server (NTRS)

    Powell, F. D.; Biegen, R. J.; Weitz, P. G., Jr.; Duke, A. M.

    1984-01-01

    Increased interest in research and technology concerning aviation turbine fuels and their properties was prompted by recent changes in the supply and demand situation of these fuels. The most obvious change is the rapid increase in fuel price. For commercial airplanes, fuel costs now approach 50 percent of the direct operating costs. In addition, there were occasional local supply disruptions and gradual shifts in delivered values of certain fuel properties. Dwindling petroleum reserves and the politically sensitive nature of the major world suppliers make the continuation of these trends likely. A summary of the principal findings, and conclusions are presented. Much of the material, especially the tables and graphs, is considered in greater detail later. The economic analysis and examination of operational considerations are described. Because some of the assumptions on which the economic analysis is founded are not easily verified, the sensitivity of the analysis to alternates for these assumptions is examined. The data base on which the analyses are founded is defined in a set of appendices.

  4. Maternal Fuels and Metabolic Measures During Pregnancy and Neonatal Body Composition: The Healthy Start Study

    PubMed Central

    Shapiro, Allison L.; Brinton, John T.; Glueck, Deborah H.; Martinez, Mercedes; Kohn, Mary; Harrod, Curtis; Friedman, Jacob E.; Dabelea, Dana

    2015-01-01

    Context: The impact of specific maternal fuels and metabolic measures during early and late gestation on neonatal body composition is not well defined. Objective: To determine how circulating maternal glucose, lipids, and insulin resistance in the first and second halves of pregnancy influence neonatal body composition. Design: A prospective pre-birth cohort enrolling pregnant women, the Healthy Start Study, was conducted, in which fasting maternal serum samples were collected twice during pregnancy to measure glucose, insulin, hemoglobin A1c, triglyceride, total cholesterol, high-density lipoprotein, and free fatty acids. Neonatal body composition was measured with air displacement plethysmography. Setting: An observational epidemiology study of pregnant women attending obstetric clinics at the University of Colorado, Anschutz Medical Center. Participants: This analysis includes 804 maternal-neonate pairs. Results: A strong positive linear relationship between maternal estimated insulin resistance (homeostasis model of assessment for insulin resistance) in the first half of pregnancy and neonatal fat mass (FM) and FM percentage (FM%) was detected, independent of prepregnancy body mass index (BMI). In the second half of pregnancy, positive linear relationships between maternal glucose levels and offspring FM and FM% were observed, independent of prepregnancy BMI. An inverse relationship was detected between high-density lipoprotein in the first half of pregnancy and FM, independent of prepregnancy BMI. Free fatty acid levels in the second half of pregnancy were positively associated with higher birth weight, independent of prepregnancy BMI. Conclusion: Maternal insulin resistance in the first half of pregnancy is highly predictive of neonatal FM%, whereas maternal glycemia, even within the normal range, is an important driver of neonatal adiposity in later pregnancy, independent of prepregnancy BMI. Our data provide additional insights on potential maternal factors

  5. Subchronic (12-week) inhalation toxicity study of methanol-fueled engine exhaust in rats

    SciTech Connect

    Maejima, Kazuhito; Suzuki, Tadao ); Numata, Hiroaki ); Maekawa, Akihiko ); Nagase, Sumi ); Ishinishi, Noburu )

    1994-01-01

    To evaluate the inhalation toxicity to rats of exhaust at low concentration for longer periods, Fischer 344 rats were exposed to 3 concentrations of exhaust generated by an M85 methanol-fueled engine (methanol with 15% gasoline) without catalyst for 8 h/d, 6 d/wk for 4, 8, or 12 wk. Concentration- and time-dependent increase carboxyhemoglobin in the erythrocytes and decrease in cytochrome P-450 in the lungs were observed in all treated groups. Furthermore, significant increases in plasma formaldehyde were observed in the group exposed to the highest concentration of exhaust (carbon monoxide, 89.8 ppm; formaldehyde, 2.3 ppm; methanol, 8.1 ppm; nitrogen oxides, 22.9 ppm; nitrogen dioxide, 1.1 ppm) for 8 or 12 wk. No change of plasma folic acid was observed in any group, and no methanol or formic acid was detected in the plasma in any animals. Histopathologically, exposure-related changes were found only in the nasal cavity of the high-concentration group. Slight hyperplasia/squamous metaplasias of the respiratory epithelium lining the nasoturbinate and maxilloturbinate were observed after 4 wk of exposure, and the incidences and degrees of these lesions increased slightly with the exposure time. No changes were found in the olfactory epithelium of the nasal cavity. As judged by optical microscopy, the exhaust concentration with no effect on the nasal cavity under the experimental conditions was concluded to be the medium concentration level containing 0.55 ppm formaldehyde. In the present study, however, concentration- and time-dependent increase of carboxyhemoglobin in the erythrocytes and decrease of the lung P-450 level were observed. Therefore, further study on more long-term inhalation of lower concentrations of exhaust might be needed. 31 refs., 2 figs., 3 tabs.

  6. Occupational exposures to emissions from combustion of diesel and alternative fuels in underground mining--a simulated pilot study.

    PubMed

    Lutz, Eric A; Reed, Rustin J; Lee, Vivien S T; Burgess, Jefferey L

    2015-01-01

    Diesel fuel is commonly used for underground mining equipment, yet diesel engine exhaust is a known human carcinogen. Alternative fuels, including biodiesel, and a natural gas/diesel blend, offer the potential to reduce engine emissions and associated health effects. For this pilot study, exposure monitoring was performed in an underground mine during operation of a load-haul-dump vehicle. Use of low-sulfur diesel, 75% biodiesel/25% diesel blend (B75), and natural gas/diesel blend (GD) fuels were compared. Personal samples were collected for total and respirable diesel particulate matter (tDPM and rDPM, respectively) and total and respirable elemental and organic carbon (tEC, rEC, tOC, rOC, respectively), as well as carbon monoxide (CO), formaldehyde, acetaldehyde, naphthalene, nitric oxide (NO), and nitrogen dioxide (NO2). Compared to diesel, B75 use was associated with a 33% reduction in rDPM, reductions in rEC, tEC, and naphthalene, increased tDPM, tOC, and NO, and no change in rOC, CO, and NO2. Compared to diesel, GD was associated with a 66% reduction in rDPM and a reduction in all other exposures except CO. The alternative fuels tested both resulted in reduced rDPM, which is the basis for the current Mine Safety and Health Administration (MSHA) occupational exposure standard. Although additional study is needed with a wider variety of equipment, use of alternative fuels have the promise of reducing exposures from vehicular exhaust in underground mining settings. PMID:25412337

  7. Occupational exposures to emissions from combustion of diesel and alternative fuels in underground mining--a simulated pilot study.

    PubMed

    Lutz, Eric A; Reed, Rustin J; Lee, Vivien S T; Burgess, Jefferey L

    2015-01-01

    Diesel fuel is commonly used for underground mining equipment, yet diesel engine exhaust is a known human carcinogen. Alternative fuels, including biodiesel, and a natural gas/diesel blend, offer the potential to reduce engine emissions and associated health effects. For this pilot study, exposure monitoring was performed in an underground mine during operation of a load-haul-dump vehicle. Use of low-sulfur diesel, 75% biodiesel/25% diesel blend (B75), and natural gas/diesel blend (GD) fuels were compared. Personal samples were collected for total and respirable diesel particulate matter (tDPM and rDPM, respectively) and total and respirable elemental and organic carbon (tEC, rEC, tOC, rOC, respectively), as well as carbon monoxide (CO), formaldehyde, acetaldehyde, naphthalene, nitric oxide (NO), and nitrogen dioxide (NO2). Compared to diesel, B75 use was associated with a 33% reduction in rDPM, reductions in rEC, tEC, and naphthalene, increased tDPM, tOC, and NO, and no change in rOC, CO, and NO2. Compared to diesel, GD was associated with a 66% reduction in rDPM and a reduction in all other exposures except CO. The alternative fuels tested both resulted in reduced rDPM, which is the basis for the current Mine Safety and Health Administration (MSHA) occupational exposure standard. Although additional study is needed with a wider variety of equipment, use of alternative fuels have the promise of reducing exposures from vehicular exhaust in underground mining settings.

  8. Analytical and numerical study on cooling flow field designs performance of PEM fuel cell with variable heat flux

    NASA Astrophysics Data System (ADS)

    Afshari, Ebrahim; Ziaei-Rad, Masoud; Jahantigh, Nabi

    2016-06-01

    In PEM fuel cells, during electrochemical generation of electricity more than half of the chemical energy of hydrogen is converted to heat. This heat of reactions, if not exhausted properly, would impair the performance and durability of the cell. In general, large scale PEM fuel cells are cooled by liquid water that circulates through coolant flow channels formed in bipolar plates or in dedicated cooling plates. In this paper, a numerical method has been presented to study cooling and temperature distribution of a polymer membrane fuel cell stack. The heat flux on the cooling plate is variable. A three-dimensional model of fluid flow and heat transfer in cooling plates with 15 cm × 15 cm square area is considered and the performances of four different coolant flow field designs, parallel field and serpentine fields are compared in terms of maximum surface temperature, temperature uniformity and pressure drop characteristics. By comparing the results in two cases, the constant and variable heat flux, it is observed that applying constant heat flux instead of variable heat flux which is actually occurring in the fuel cells is not an accurate assumption. The numerical results indicated that the straight flow field model has temperature uniformity index and almost the same temperature difference with the serpentine models, while its pressure drop is less than all of the serpentine models. Another important advantage of this model is the much easier design and building than the spiral models.

  9. Organic carbonyl compounds in Albuquerque, New Mexico, air: A preliminary study of the effects of oxygenated fuel use

    SciTech Connect

    Popp, C.J.; Zhang, Lin; Gaffney, J.S.

    1993-06-01

    A suite of inorganic and organic species were analyzed for four 2--4 day time periods over a year in Albuquerque, New Mexico to determine baseline conditions for organic pollutants under the current air pollution control parameters. Concentrations of low molecular weight carbonyl compounds were relatively high compared with areas such as Los Angeles. Formio acid concentrations in air samples were significant even in winter. In addition, ratios of peroxypropionyl nitrate to peroxyacyetyl nitrate are higher than expected and may be related to the use of oxygenated fuels which are used to mitigate CO concentrations. The number of CO violations in Albuquerque has decreased steadily since 1982 and the downward trend has continued since 1989 when oxygenated fuel use was mandated. It is, therefore, difficult to correlate the drop in CO violations directly to the use of oxygenated fuels when such factors as fleet turnover, woodburning controls, emissions testing and meteorological conditions also may be playing significant roles. More detailed studies are needed to determine the specific relationship between the use of oxygenated fuels and the air quality in Albuquerque, New Mexico and similar urban areas in the western United States.

  10. Fuel pin

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Leggett, R.D.; Baker, R.B.

    1987-11-24

    A fuel pin for a liquid metal nuclear reactor is provided. The fuel pin includes a generally cylindrical cladding member with metallic fuel material disposed therein. At least a portion of the fuel material extends radially outwardly to the inner diameter of the cladding member to promote efficient transfer of heat to the reactor coolant system. The fuel material defines at least one void space therein to facilitate swelling of the fuel material during fission.

  11. Grid-to-rod flow-induced impact study for PWR fuel in reactor

    DOE PAGES

    Jiang, Hao; Qu, Jun; Lu, Roger Y.; Wang, Jy-An John

    2016-06-10

    The source for grid-to-rod fretting in a pressurized water nuclear reactor (PWR) is the dynamic contact impact from hydraulic flow-induced fuel assembly vibration. In order to support grid-to-rod fretting wear mitigation research, finite element analysis (FEA) was used to evaluate the hydraulic flow-induced impact intensity between the fuel rods and the spacer grids. Three-dimensional FEA models, with detailed geometries of the dimple and spring of the actual spacer grids along with fuel rods, were developed for flow impact simulation. The grid-to-rod dynamic impact simulation provided insights of the contact phenomena at grid-rod interface. Finally, it is an essential and effectivemore » way to evaluate contact forces and provide guidance for simulative bench fretting-impact tests.« less

  12. An experimental and modeling study of fires in ventilated ducts; Part 1: Liquid fuels

    SciTech Connect

    Comitis, S.C.; Glasser, D.; Young, B.D. . Dept. of Chemical Engineering)

    1994-03-01

    A theoretical model for fire propagation through a fuel-lined duct with a radially well-mixed axial flow is presented. The gas-phase is modeled as a steady-state process whereas the condensed-phase (fuel source) is taken to be the cause of transient fire propagation along the duct. Experiments were performed in a small-scale duct where fire propagation and gas temperature histories were acquired. Experimental results confirm hypotheses of pseudo-steady-state gas-phase processes. Theory and experiment display transient fire propagation for typical duct fire scenarios where initial fuel mass loading is constant with respect to duct length. The phenomena observed, as predicted by theory, is an initial jump'' of the fully developed combustion process followed by convergence to a steady-state constant fire propagation speed. The theory is in all important aspects able to quantitatively model the experimental results.

  13. Study on secondary atomization of liquid fuel at the lip of the flameholder

    NASA Astrophysics Data System (ADS)

    Yang, Maolin; Huang, Yong; Gu, Shanjiang; Zhang, Yingnian

    1992-01-01

    An experimental investigation of secondary atomization of liquid fuel at the lip of the flameholder has been completed by means of the Malvern Particle-Sizer. This secondary atomization has several features: fine droplets occur in the high speed air flow side, while gross droplets occur in the recirculation zone side; the velocity of air flow has a predominant influence on the mean drop size of the spray which may be expressed quantitatively. The mechanism of the secondary atomization may be described as follows: some of the liquid drops in the spray are gathered by the flameholder and form a fuel film in its surface, the air flow forces the wavy film to move forward to the lip of the flameholder, and the fuel film breaks up at flameholder lip under a pincer attack of high speed turbulent flow and low speed recirculation flow.

  14. High-silicon 238PuO2 fuel characterization study: Half module impact tests

    NASA Astrophysics Data System (ADS)

    Reimus, Mary Ann H.

    1997-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of 238Pu decay to an array of thermoelectric elements. The modular GPHS design was developed to address both survivability during launch abort and return from orbit. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs to a variety of fragment-impact, aging, atmospheric reentry, and Earth-impact conditions. The evaluations documented in this report are part of an ongoing program to determine the effect of fuel impurities on the response of the heat source to conditions baselined during the Galileo/Ulysses test program. In the first two tests in this series, encapsulated GPHS fuel pellets containing high levels of silicon were aged, loaded into GPHS module halves, and impacted against steel plates. The results show no significant differences between the response of these capsules and the behavior of relatively low-silicon fuel pellets tested previously.

  15. Development of U-frame bending system for studying the vibration integrity of spent nuclear fuel

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Wang, Jy-An John; Tan, Ting; Jiang, Hao; Cox, Thomas S.; Howard, Rob L.; Bevard, Bruce B.; Flanagan, Michelle

    2013-09-01

    A bending fatigue system developed to evaluate the response of spent nuclear fuel rods to vibration loads is presented. A U-frame testing setup is used for imposing bending loads on the fuel rod specimen. The U-frame setup consists of two rigid arms, side connecting plates to the rigid arms, and linkages to a universal testing machine. The test specimen's curvature is obtained through a three-point deflection measurement method. The tests using surrogate specimens with stainless steel cladding revealed increased flexural rigidity under unidirectional cyclic bending, significant effect of cladding-pellets bonding on the response of surrogate rods, and substantial cyclic softening in reverse bending mode. These phenomena may cast light on the expected response of a spent nuclear fuel rod. The developed U-frame system is thus verified and demonstrated to be ready for further pursuit in hot-cell tests.

  16. A Study of Pollutant Formation from the Lean Premixed Combustion of Gaseous Fuel Alternatives to Natural Gas

    NASA Astrophysics Data System (ADS)

    Fackler, Keith Boyd, Jr.

    The goal of this research is to identify how nitrogen oxide (NO x) emissions and flame stability (blowout) are impacted by the use of fuels that are alternatives to typical pipeline natural gas. The research focuses on lean, premixed combustors that are typically used in state-of-the-art natural gas fueled systems. An idealized laboratory lean premixed combustor, specifically the jet-stirred reactor, is used for experimental data. A series of models, including those featuring detailed fluid dynamics and those focusing on detailed chemistry, are used to interpret the data and understand the underlying chemical kinetic reasons for differences in emissions between the various fuel blends. An ultimate goal is to use these data and interpretive tools to develop a way to predict the emission and stability impacts of changing fuels within practical combustors. All experimental results are obtained from a high intensity, single-jet stirred reactor (JSR). Five fuel categories are studied: (1) pure H 2, (2) process and refinery gas, including combinations of H2, CH4, C2H6, and C3H8, (3) oxygen blown gasified coal/petcoke composed of H2, CO, and CO2, (4) landfill and digester gas composed of CH4, CO2, and N2, and (5) liquified natural gas (LNG)/shale/associated gases composed of CH4, C2H6, and C3 H8. NOx measurements are taken at a nominal combustion temperature of 1800 K, atmospheric pressure, and a reactor residence time of 3 ms. This is done to focus the results on differences caused by fuel chemistry by comparing all fuels at a common temperature, pressure, and residence time. This is one of the few studies in the literature that attempts to remove these effects when studying fuels varying in composition. Additionally, the effects of changing temperature and residence time are investigated for selected fuels. At the nominal temperature and residence time, the experimental and modeling results show the following trends for NOx emissions as a function of fuel type: 1.) NOx

  17. Reduced Gravity Studies of Soret Transport Effects in Liquid Fuel Combustion

    NASA Technical Reports Server (NTRS)

    Shaw, Benjamin D.

    2004-01-01

    Soret transport, which is mass transport driven by thermal gradients, can be important in practical flames as well as laboratory flames by influencing transport of low molecular weight species (e.g., monatomic and diatomic hydrogen). In addition, gas-phase Soret transport of high molecular weight fuel species that are present in practical liquid fuels (e.g., octane or methanol) can be significant in practical flames (Rosner et al., 2000; Dakhlia et al., 2002) and in high pressure droplet evaporation (Curtis and Farrell, 1992), and it has also been shown that Soret transport effects can be important in determining oxygen diffusion rates in certain classes of microgravity droplet combustion experiments (Aharon and Shaw, 1998). It is thus useful to obtain information on flames under conditions where Soret effects can be clearly observed. This research is concerned with investigating effects of Soret transport on combustion of liquid fuels, in particular liquid fuel droplets. Reduced-gravity is employed to provide an ideal (spherically-symmetrical) experimental model with which to investigate effects of Soret transport on combustion. The research will involve performing reduced-gravity experiments on combustion of liquid fuel droplets in environments where Soret effects significantly influence transport of fuel and oxygen to flame zones. Experiments will also be performed where Soret effects are not expected to be important. Droplets initially in the 0.5 to 1 mm size range will be burned. Data will be obtained on influences of Soret transport on combustion characteristics (e.g., droplet burning rates, droplet lifetimes, gas-phase extinction, and transient flame behaviors) under simplified geometrical conditions that are most amenable to theoretical modeling (i.e., spherical symmetry). The experiments will be compared with existing theoretical models as well as new models that will be developed. Normal gravity experiments will also be performed.

  18. PRELIMINARY STUDY OF CERAMICS FOR IMMOBILIZATION OF ADVANCED FUEL CYCLE REPROCESSING WASTES

    SciTech Connect

    Fox, K.; Billings, A.; Brinkman, K.; Marra, J.

    2010-09-22

    The Savannah River National Laboratory (SRNL) developed a series of ceramic waste forms for the immobilization of Cesium/Lanthanide (CS/LN) and Cesium/Lanthanide/Transition Metal (CS/LN/TM) waste streams anticipated to result from nuclear fuel reprocessing. Simple raw materials, including Al{sub 2}O{sub 3}, CaO, and TiO{sub 2} were combined with simulated waste components to produce multiphase ceramics containing hollandite-type phases, perovskites (particularly BaTiO{sub 3}), pyrochlores, zirconolite, and other minor metal titanate phases. Identification of excess Al{sub 2}O{sub 3} via X-ray Diffraction (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM/EDS) in the first series of compositions led to a Phase II study, with significantly reduced Al{sub 2}O{sub 3} concentrations and increased waste loadings. Three fabrication methodologies were used, including melting and crystallizing, pressing and sintering, and Spark Plasma Sintering (SPS), with the intent of studying phase evolution under various sintering conditions. XRD and SEM/EDS results showed that the partitioning of the waste elements in the sintered materials was very similar, despite varying stoichiometry of the phases formed. The Phase II compositions generally contained a reduced amount of unreacted Al{sub 2}O{sub 3} as identified by XRD, and had phase assemblages that were closer to the initial targets. Chemical composition measurements showed no significant issues with meeting the target compositions. However, volatilization of Cs and Mo was identified, particularly during melting, since sintering of the pressed pellets and SPS were performed at lower temperatures. Partitioning of some of the waste components was difficult to determine via XRD. SEM/EDS mapping showed that those elements, which were generally present in small concentrations, were well distributed throughout the waste forms. Initial studies of radiation damage tolerance using ion beam irradiation at Los

  19. A comparative study of water uptake by and transport through ionomeric fuel cell membranes

    SciTech Connect

    Zawodzinski, T.A.Jr.; Springer, T.E.; Davey, J.; Jestel, R.; Lopez, C.; Valerio, J.; Gottesfeld, S. . Electronics Materials and Device Research)

    1993-07-01

    Water uptake and transport parameters measured at 30 C for several available perfluorosulfonic acid membranes are compared. The water sorption characteristics, diffusion coefficient of water, electroosmotic drag, and protonic conductivity were determined for Nafion 117, Membrane C, and Dow XUS 13204.10 developmental fuel cell membrane. The diffusion coefficient and conductivity of each of these membranes were determined as functions of membrane water content. Experimental determination of transport parameters, enables one to compare membranes without the skewing effects of extensive features such as membrane thickness which contributes in a nonlinear fashion to performance in polymer electrolyte fuel cells.

  20. Study of component technologies for fuel cell on-site integrated energy system. Volume 2: Appendices

    NASA Technical Reports Server (NTRS)

    Lee, W. D.; Mathias, S.

    1980-01-01

    This data base catalogue was compiled in order to facilitate the analysis of various on site integrated energy system with fuel cell power plants. The catalogue is divided into two sections. The first characterizes individual components in terms of their performance profiles as a function of design parameters. The second characterizes total heating and cooling systems in terms of energy output as a function of input and control variables. The integrated fuel cell systems diagrams and the computer analysis of systems are included as well as the cash flows series for baseline systems.

  1. Structural Path Analysis of Fossil Fuel Based CO2 Emissions: A Case Study for China.

    PubMed

    Yang, Zhiyong; Dong, Wenjie; Xiu, Jinfeng; Dai, Rufeng; Chou, Jieming

    2015-01-01

    Environmentally extended input-output analysis (EEIOA) has long been used to quantify global and regional environmental impacts and to clarify emission transfers. Structural path analysis (SPA), a technique based on EEIOA, is especially useful for measuring significant flows in this environmental-economic system. This paper constructs an imports-adjusted single-region input-output (SRIO) model considering only domestic final use elements, and it uses the SPA technique to highlight crucial routes along the production chain in both final use and sectoral perspectives. The results indicate that future mitigation policies on household consumption should change direct energy use structures in rural areas, cut unreasonable demand for power and chemical products, and focus on urban areas due to their consistently higher magnitudes than rural areas in the structural routes. Impacts originating from government spending should be tackled by managing onsite energy use in 3 major service sectors and promoting cleaner fuels and energy-saving techniques in the transport sector. Policies on investment should concentrate on sectoral interrelationships along the production chain by setting up standards to regulate upstream industries, especially for the services, construction and equipment manufacturing sectors, which have high demand pulling effects. Apart from the similar methods above, mitigating policies in exports should also consider improving embodied technology and quality in manufactured products to achieve sustainable development. Additionally, detailed sectoral results in the coal extraction industry highlight the onsite energy use management in large domestic companies, emphasize energy structure rearrangement, and indicate resources and energy safety issues. Conclusions based on the construction and public administration sectors reveal that future mitigation in secondary and tertiary industries should be combined with upstream emission intensive industries in a

  2. Structural Path Analysis of Fossil Fuel Based CO2 Emissions: A Case Study for China.

    PubMed

    Yang, Zhiyong; Dong, Wenjie; Xiu, Jinfeng; Dai, Rufeng; Chou, Jieming

    2015-01-01

    Environmentally extended input-output analysis (EEIOA) has long been used to quantify global and regional environmental impacts and to clarify emission transfers. Structural path analysis (SPA), a technique based on EEIOA, is especially useful for measuring significant flows in this environmental-economic system. This paper constructs an imports-adjusted single-region input-output (SRIO) model considering only domestic final use elements, and it uses the SPA technique to highlight crucial routes along the production chain in both final use and sectoral perspectives. The results indicate that future mitigation policies on household consumption should change direct energy use structures in rural areas, cut unreasonable demand for power and chemical products, and focus on urban areas due to their consistently higher magnitudes than rural areas in the structural routes. Impacts originating from government spending should be tackled by managing onsite energy use in 3 major service sectors and promoting cleaner fuels and energy-saving techniques in the transport sector. Policies on investment should concentrate on sectoral interrelationships along the production chain by setting up standards to regulate upstream industries, especially for the services, construction and equipment manufacturing sectors, which have high demand pulling effects. Apart from the similar methods above, mitigating policies in exports should also consider improving embodied technology and quality in manufactured products to achieve sustainable development. Additionally, detailed sectoral results in the coal extraction industry highlight the onsite energy use management in large domestic companies, emphasize energy structure rearrangement, and indicate resources and energy safety issues. Conclusions based on the construction and public administration sectors reveal that future mitigation in secondary and tertiary industries should be combined with upstream emission intensive industries in a

  3. Electrochemical study of lithiated transition metal oxide composite for single layer fuel cell

    NASA Astrophysics Data System (ADS)

    Hu, Huiqing; Lin, Qizhao; Muhammad, Afzal; Zhu, Bin

    2015-07-01

    This study analyzed the effect of various semiconductors of transition metal oxides in modified lithiated NiO on the electrochemical performance of a single layer fuel cell (SLFC). A typical ionic conductor Ce0.8Sm0.2O2-δ (SDC) and three types of semiconductors Li0.3Ni0.6Cu0.07Sr0.03O2-δ (LNCuS), Li0.3Ni0.6Mn0.07Sr0.03O2-δ (LNMnS) and Li0.3Ni0.6Co0.07Sr0.03O2-δ (LNCoS), were the fundamental components of the SLFCs. The components were characterized by using X-ray diffraction (XRD), a scanning electron microscope (SEM), and an energy-dispersive X-ray spectrometer (EDS). The stability of the synthesized materials was evaluated using thermal gravity analysis (TGA). The ohmic resistances at 500 °C were 0.36, 0.48 and 0.58 Ω cm2 for 6SDC-4LNMnS, 6SDC-4LNCoS and 6SDC-4LNCuS, respectively. Among the three SLFCs, the single cell with 6SDC-4LNMnS achieves the highest power density (422 mW cm-2) but the lowest temperature stability, while the single cell with 6SDC-4LNCuS achieved the lowest power density (331 mW cm-2) but the highest temperature stability during the operation temperature.

  4. Structural Path Analysis of Fossil Fuel Based CO2 Emissions: A Case Study for China

    PubMed Central

    Yang, Zhiyong; Dong, Wenjie; Xiu, Jinfeng; Dai, Rufeng; Chou, Jieming

    2015-01-01

    Environmentally extended input-output analysis (EEIOA) has long been used to quantify global and regional environmental impacts and to clarify emission transfers. Structural path analysis (SPA), a technique based on EEIOA, is especially useful for measuring significant flows in this environmental-economic system. This paper constructs an imports-adjusted single-region input-output (SRIO) model considering only domestic final use elements, and it uses the SPA technique to highlight crucial routes along the production chain in both final use and sectoral perspectives. The results indicate that future mitigation policies on household consumption should change direct energy use structures in rural areas, cut unreasonable demand for power and chemical products, and focus on urban areas due to their consistently higher magnitudes than rural areas in the structural routes. Impacts originating from government spending should be tackled by managing onsite energy use in 3 major service sectors and promoting cleaner fuels and energy-saving techniques in the transport sector. Policies on investment should concentrate on sectoral interrelationships along the production chain by setting up standards to regulate upstream industries, especially for the services, construction and equipment manufacturing sectors, which have high demand pulling effects. Apart from the similar methods above, mitigating policies in exports should also consider improving embodied technology and quality in manufactured products to achieve sustainable development. Additionally, detailed sectoral results in the coal extraction industry highlight the onsite energy use management in large domestic companies, emphasize energy structure rearrangement, and indicate resources and energy safety issues. Conclusions based on the construction and public administration sectors reveal that future mitigation in secondary and tertiary industries should be combined with upstream emission intensive industries in a

  5. Neutronics Study on Accelerator Driven Subcritical Systems with Thorium-Based Fuel for Comparison Between Solid and Molten-Salt Fuels

    SciTech Connect

    Ishimoto, Shunsuke; Ishibashi, Kenji; Tenzou, Hideki; Sasa, Toshinobu

    2002-06-15

    Since thorium is an abundant fertile material, there is hope for the thorium-cycle fuels for an accelerator driven subcritical system (ADS). The ADS utilizes neutrons, which are generated by high-energy protons of giga-electron-volt-grade, but cross sections for the interaction of high-energy particles are not available for use in current ADS engineering design. In this paper the neutron behavior in the ADS target based on the related experimental data is clarified, and the feasibility of the ADS regarding both the molten salts (Flibe: {sup 7}LiF-BeF{sub 2}-ThF{sub 4}-{sup 233}UF{sub 4}, chloride: NaCl-ThCl{sub 4}-{sup 233}UCl{sub 4}) and oxide ([Th, {sup 233}U]O{sub 2}) fuels is examined. The difference between the experiment and the calculated result at the ADS high-energy region is discussed. In a comparison of the fuels, the time evolution of k{sub eff} and the beam current in the burning period are calculated. The calculated results suggest that the ADS with solid fuel has better future prospects than that with molten-salt fuels. The ADS with Flibe molten-salt fuel tends to require a high beam current and consequently needs the installation of a metallic spallation target and the continuous removal for fission products and protactinium. In comparison with the Flibe fuel, the ADS with chloride fuel has a flux distribution that is similar to a solid fuel reactor.

  6. A Study of Pollutant Formation from the Lean Premixed Combustion of Gaseous Fuel Alternatives to Natural Gas

    NASA Astrophysics Data System (ADS)

    Fackler, Keith Boyd, Jr.

    The goal of this research is to identify how nitrogen oxide (NO x) emissions and flame stability (blowout) are impacted by the use of fuels that are alternatives to typical pipeline natural gas. The research focuses on lean, premixed combustors that are typically used in state-of-the-art natural gas fueled systems. An idealized laboratory lean premixed combustor, specifically the jet-stirred reactor, is used for experimental data. A series of models, including those featuring detailed fluid dynamics and those focusing on detailed chemistry, are used to interpret the data and understand the underlying chemical kinetic reasons for differences in emissions between the various fuel blends. An ultimate goal is to use these data and interpretive tools to develop a way to predict the emission and stability impacts of changing fuels within practical combustors. All experimental results are obtained from a high intensity, single-jet stirred reactor (JSR). Five fuel categories are studied: (1) pure H 2, (2) process and refinery gas, including combinations of H2, CH4, C2H6, and C3H8, (3) oxygen blown gasified coal/petcoke composed of H2, CO, and CO2, (4) landfill and digester gas composed of CH4, CO2, and N2, and (5) liquified natural gas (LNG)/shale/associated gases composed of CH4, C2H6, and C3 H8. NOx measurements are taken at a nominal combustion temperature of 1800 K, atmospheric pressure, and a reactor residence time of 3 ms. This is done to focus the results on differences caused by fuel chemistry by comparing all fuels at a common temperature, pressure, and residence time. This is one of the few studies in the literature that attempts to remove these effects when studying fuels varying in composition. Additionally, the effects of changing temperature and residence time are investigated for selected fuels. At the nominal temperature and residence time, the experimental and modeling results show the following trends for NOx emissions as a function of fuel type: 1.) NOx

  7. Studies on sulfur poisoning and development of advanced anodic materials for waste-to-energy fuel cells applications

    NASA Astrophysics Data System (ADS)

    Zaza, Fabio; Paoletti, Claudia; LoPresti, Roberto; Simonetti, Elisabetta; Pasquali, Mauro

    Biomass is the renewable energy source with the most potential penetration in energy market for its positive environmental and socio-economic consequences: biomass live cycles for energy production is carbon neutral; energy crops promote alternative and productive utilizations of rural sites creating new economic opportunities; bioenergy productions promote local energy independence and global energy security defined as availability of energy resource supply. Different technologies are currently available for energy production from biomass, but a key role is played by fuel cells which have both low environmental impacts and high efficiencies. High temperature fuel cells, such as molten carbonate fuel cells (MCFC), are particularly suitable for bioenergy production because it can be directly fed with biogas: in fact, among its principal constituents, methane can be transformed to hydrogen by internal reforming; carbon dioxide is a safe diluent; carbon monoxide is not a poison, but both a fuel, because it can be discharged at the anode, and a hydrogen supplier, because it can produce hydrogen via the water-gas shift reaction. However, the utilization of biomass derived fuels in MCFC presents different problems not yet solved, such as the poisoning of the anode due to byproducts of biofuel chemical processing. The chemical compound with the major negative effects on cell performances is hydrogen sulfide. It reacts with nickel, the main anodic constituent, forming sulfides and blocking catalytic sites for electrode reactions. The aim of this work is to study the hydrogen sulfide effects on MCFC performances for defining the poisoning mechanisms of conventional nickel-based anode, recommending selection criteria of sulfur-tolerant materials, and selecting advanced anodes for MCFC fed with biogas.

  8. Experimental Study on the Influence of the Supporting Condition and Rod Motion on the Fuel Fretting Damage

    SciTech Connect

    Kim, Hyung-Kyu; Lee, Young-Ho

    2007-07-01

    Present study focuses on the influence of a supporting condition and a rod motion on a fuel fretting wear through experiments using a self-developed wear simulator, which was presented at the Water Reactor Fuel Performance Meeting, Kyoto Japan in 2005. In the experiment, a fuel rod specimen of two span lengths is vibrated by two perpendicularly aligned electromagnetic actuators. Both ends of the rod specimen are supported with a positive contact force and a variation of the supporting condition is simulated by moving each of the four grid strap specimens constituting a center grid cell. As for the supporting condition, 0.1 mm gap and 10 N force are used; a circular and a diagonal traces are applied for the rod motion. The contact shape of the spring/dimple is concave, to try and increase the contact area. Both the spring/dimple and fuel rod specimens were fabricated from the as-received materials (zirconium alloy) for a commercial fuel assembly. Experiments are carried out under a room temperature and distilled water condition. Experiment of each condition is carried out for 72 hours. Wear volume, area and depth on the cladding tubes are examined. As a result, the present concave shaped spring/dimple causes less wear when the rod moves in a circular manner than a diagonal one if there is a positive contact force (10 N). However, a diagonal motion causes more wear when a gap (0.1 mm) exists. Wear amount at the spring and dimple is influenced by the location of them and the rod motion. It is found that the wear is concentrated at the contact edges between the spring/dimple and rods due to the contact shape. The influence of the rod motion on the worn area and its shape is also discussed. (authors)

  9. Computational And Experimental Studies Of Three-Dimensional Flame Spread Over Liquid Fuel Pools

    NASA Technical Reports Server (NTRS)

    Ross, Howard D. (Technical Monitor); Cai, Jinsheng; Liu, Feng; Sirignano, William A.; Miller, Fletcher J.

    2003-01-01

    Schiller, Ross, and Sirignano (1996) studied ignition and flame spread above liquid fuels initially below the flashpoint temperature by using a two-dimensional computational fluid dynamics code that solves the coupled equations of both the gas and the liquid phases. Pulsating flame spread was attributed to the establishment of a gas-phase recirculation cell that forms just ahead of the flame leading edge because of the opposing effect of buoyancy-driven flow in the gas phase and the thermocapillary-driven flow in the liquid phase. Schiller and Sirignano (1996) extended the same study to include flame spread with forced opposed flow in the gas phase. A transitional flow velocity was found above which an originally uniform spreading flame pulsates. The same type of gas-phase recirculation cell caused by the combination of forced opposed flow, buoyancy-driven flow, and thermocapillary-driven concurrent flow was responsible for the pulsating flame spread. Ross and Miller (1998) and Miller and Ross (1998) performed experimental work that corroborates the computational findings of Schiller, Ross, and Sirignano (1996) and Schiller and Sirignano (1996). Cai, Liu, and Sirignano (2002) developed a more comprehensive three-dimensional model and computer code for the flame spread problem. Many improvements in modeling and numerical algorithms were incorporated in the three-dimensional model. Pools of finite width and length were studied in air channels of prescribed height and width. Significant three-dimensional effects around and along the pool edge were observed. The same three-dimensional code is used to study the detailed effects of pool depth, pool width, opposed air flow velocity, and different levels of air oxygen concentration (Cai, Liu, and Sirignano, 2003). Significant three-dimensional effects showing an unsteady wavy flame front for cases of wide pool width are found for the first time in computation, after being noted previously by experimental observers (Ross

  10. Fuel Cell Power Model Version 2: Startup Guide, System Designs, and Case Studies. Modeling Electricity, Heat, and Hydrogen Generation from Fuel Cell-Based Distributed Energy Systems

    SciTech Connect

    Steward, D.; Penev, M.; Saur, G.; Becker, W.; Zuboy, J.

    2013-06-01

    This guide helps users get started with the U.S. Department of Energy/National Renewable Energy Laboratory Fuel Cell Power (FCPower) Model Version 2, which is a Microsoft Excel workbook that analyzes the technical and economic aspects of high-temperature fuel cell-based distributed energy systems with the aim of providing consistent, transparent, comparable results. This type of energy system would provide onsite-generated heat and electricity to large end users such as hospitals and office complexes. The hydrogen produced could be used for fueling vehicles or stored for later conversion to electricity.

  11. A FEASIBILITY STUDY FOR THE COPROCESSING OF FOSSIL FUELS WITH BIOMASS BY THE HYDROCARB PROCESS

    EPA Science Inventory

    The report describes and gives results of an assessment of a new process concept for the production of carbon and methanol from fossil fuels. The Hydrocarb Process consists of the hydrogasification of carbonaceous material to produce methane, which is subsequently thermally decom...

  12. LIFE CYCLE BASED STUDIES ON BIOETHANOL FUEL FOR SUSTAINABLE TRANSPORTATION: A LITERATURE REVIEW

    EPA Science Inventory

    A literature search was conducted and revealed 45 publications (1996-2005) that compare bio-ethanol systems to conventional fuel on a life-cycle basis, or using life cycle assessment. Feedstocks, such as sugar beets, wheat, potato, sugar cane, and corn, have been investigated in...

  13. Study and development of sulfated zirconia based proton exchange fuel cell membranes

    NASA Astrophysics Data System (ADS)

    Kemp, Brittany Wilson

    With the increasing consumption of energy, fuel cells are among the most promising alternatives to fossil fuels, provided some technical challenges are overcome. Proton exchange membrane fuel cells (PEMFCs) have been investigated and improvements have been made, but the problem with NafionRTM, the main membrane for PEMFCs, has not been solved. NafionRTM restricts the membranes from operating at higher temperatures, thus preventing them from working in small electronics. The problem is to develop a novel fuel cell membrane that performs comparably to NafionRTM in PEMFCs. The membranes were fabricated by applying sulfated zirconia, via template wetting, to porous alumina membranes. The fabricated membranes showed a proton conductivity of 0.016 S/cm in comparison to the proton conductivity of Nafion RTM (0.05 S/cm). Both formic acid and methanol had a lower crossover flux through the sulfated zirconia membranes (formic acid- 2.89x10 -7 mols/cm2s and methanol-1.78x10-9 mols/cm2s) than through NafionRTM (formic acid-2.03x10 -8 mols/cm2s methanol-2.42x10-6 mols/cm 2s), indicating that a sulfated zirconia PEMFC may serve as a replacement for NafionRTM.

  14. GREENHOUSE GASES FROM BIOMASS AND FOSSIL FUEL STOVES IN DEVELOPING COUNTRIES: A MANILA PILOT STUDY

    EPA Science Inventory

    Samples were taken of the combustion gases released by household cookstoves in Manila, Philippines. In a total of 24 samples, 14 cookstoves were tested. These were fueled by liquefied petroleum gas (LPG), kerosene (three kinds of stoves), charcoal, and wood. Ambient samples were ...

  15. Laser fluorescence studies of the chemical interactions of sodium species with sulfur bearing fuels

    NASA Technical Reports Server (NTRS)

    Steinberg, M.; Schofield, K.

    1983-01-01

    By using a large matrix of fuel rich and fuel lean H2/O2/N2 and fuel rich C2H2/O2/N2 flames, the behavior of sodium and its interactions with sulfur at high temperatures was extensively characterized. OH concentrations were measured for each flame using the previously validated laser induced fluorescence technique. Sodium atomic concentrations were obtained by the saturated laser fluorescence method. Measurements were made in the absence and presence of up to 2% sulfur. In oxygen rich systems sodium is depleted by NaO2 and NaOH formation. The relative amounts of each are controlled by the degree of nonequilibration of the flame radicals and by the temperature. The bond strength of NaO2 was established. For the first time, a complete understanding of the complex behavior of sodium in fuel lean H2/O2 flames has emerged and computer modeling has permitted various rate constants of Na, NaO2 and NaOH reactions to be approximately fixed.

  16. Non-intrusive Experimental Study on Nuclear Fuel Assembly Response to Seismic Loads

    NASA Astrophysics Data System (ADS)

    Weichselbaum, Noah A.

    Experimental measurements of nuclear fuel bundle response to seismic loads have primarily been focused on the response of the structure. Forcing methods have included use of shake tables, however, the majority of work has used hydraulic actuators rigidly connected to a single spacer grid to force the fuel bundle. Structural measurements utilize such instruments as linear variable displacement transducers (LVDT) that are mounted on the structure. From these measurements it has been shown that fuel bundles in prototypical conditions, with an axial flow of 6 m/s, behave markedly different from fuel bundles in still water when there is external forcing on the core from an earthquake. It has also been shown that the structure and fluid are fully coupled. Thus more recently attention has been focused on fluid measurements in the bypass region around fuel bundles with external forcing with laser doppler velocimetry (LDV), which is a point wise fluid velocity measurement technique. This work describes a unique facility that has garnered a large experimental database of fully coupled fluid and structure measurements with time resolved particle image velocimetry (PIV) and digital image correlation (DIC) within a full height 6x6 fuel bundle exposed to seismic forcing on a large 6 degree of freedom shake table. A refractive index matched (RIM) vertical liquid tunnel is mounted on the shake table and houses the fuel bundle which is based on the geometry of a prototypical fuel bundle in a pressurized water reactor (PWR). PIV is obtained with high spatial resolution by rigidly mounting all optical equipment to the test section on the shake table, where the laser light is delivered through high power multi-mode step index fiber optics from a high powered Nd:YLF laser located 10 meters away from the test section. High temporal resolution for the PIV measurements is obtained with state of the art high speed CMOS cameras that record straight to hard drive allowing for increased

  17. Studies on the new fuels with Santilli magnecular structure and their industrial applications

    SciTech Connect

    Pandhurnekar, Chandrashekhar P.

    2015-03-10

    Professor R. M. Santilli, the Italian-American physicist, for the first time in the history of Science, presented the theoretical and experimental evidence on the existence of the new chemical species of “magnecules” [1]. This new species mainly consist of individual atoms, radicals and conventional molecules bonded together with stable clusters under the new attractive force primarily originating from torroidal polarization of orbitals of atomic electrons under strong magnetic field. The main contribution in this area was the production of Magnegas{sup TM}, new clean fuels developed by Prof. Santilli, which are produced as byproducts of recycling nonradioactive liquid feedstock such as antifreeze waste, engine oil waste, town sewage, crude oil, etc., and generally vary with the liquid used for their production. A new technology, called Plasma Arc FlowTM, flows the waste through a submerged electric arc between conventional electrodes. The arc decomposes the liquid molecules into their atomic constituents, and forms a plasma in the immediate vicinity of the electrodes at about 10,000{sup 0} F. The technology then moves the plasma away from the electrodes, and controls its recombination into environmentally acceptable fuels. In fact, the exhaust of magnegases shows: absence of carcinogenic or other toxic substances; breathable oxygen up 14 percent; and carbon dioxide down to 0.01 percent. Since, in addition, the new fuels can be produced everywhere, and have environmentally acceptable exhausts, Magnegases offer promising possibilities to satisfy our ever increasing energy needs, as well as to contain the alarming environmental problems caused by fossil fuels. Thus, it was thought worthwhile to present some of the industrial applications of environmentally benign fuel consisting magnecular bonds [2, 3, 4, 5]. Also in the present communications, some of the experimental evidences of Santilli’s new chemical species i. e. Magnecules which had been published

  18. Study of metallic materials for solid oxide fuel cell interconnect applications.

    SciTech Connect

    Natesan, K.; Zeng, Z.; Nuclear Engineering Division

    2009-04-24

    Metallic interconnect acts as a gas separator and a gas distributor and therefore, it needs to function adequately in two widely different environments. The interconnect material will be exposed to air on one side and natural gas or coal-derived synthesis gas on the other side. The viable material for the interconnect application must be resistant not only to oxidation but also carburization in hydrocarbon containing low-oxygen environments. In addition, the scales that develop on the exposed surfaces must possess adequate electrical conductivity for them to function as current leads over long service life of the fuel cell. This report addresses five topics of interest for the development of metallic interconnects with adequate performance in fuel cells for long service life. The research conducted over the years and the conclusions reached were used to identify additional areas of research on materials for improved performance of components, especially metallic interconnects, in the complex fuel cell environments. This report details research conducted in the following areas: measurement of area specific electrical resistivity, corrosion performance in dual gas environments by experiments using alloy 446, long term corrosion performance of ferritic and austenitic alloys in hydrogen and methane-reformed synthesis fuel-gas environments, approaches to reduce the area resistance of metallic interconnect, and reduction of electrical resistivity of alumina scales on metallic interconnect. Based on the key requirements for metallic interconnects and the data developed on the corrosion behavior of candidate materials in meeting those requirements, several areas are recommended for further research to develop metallic interconnects with acceptable and reliable long-term performance in solid oxide fuel cells.

  19. Lessons learnt from VERCORS tests.. Study of the active role played by UO 2-ZrO 2-FP interactions on irradiated fuel collapse temperature

    NASA Astrophysics Data System (ADS)

    Pontillon, Y.; Malgouyres, P. P.; Ducros, G.; Nicaise, G.; Dubourg, R.; Kissane, M.; Baichi, M.

    2005-09-01

    The VERCORS experimental program was launched in order to study radionuclide release from standard PWR fuels and quantify the corresponding source term in severe-accident conditions. Performed by the CEA, it forms part of a larger program concerning reactor-accident studies funded by the IRSN in collaboration with EDF. Twenty-five experiments have been performed leading to a large database regarding release of fission products and actinides from UO 2 and MOX fuels under several types of atmosphere. The fuel burn-up ranges from 38 GWd/t to 70 GWd/t. Nearly all the tests were performed in such a way as to measure with some accuracy the fuel temperature. The present paper gives an overview of the program (i.e. sample and loop description, general FPs behaviour), with emphasis on the potential effect of UO 2-ZrO 2-FP interactions on fuel collapse temperature.

  20. Theoretical studies of oxides relevant to the combustion of fossil fuels

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Michael

    Anthropogenic pollution has greatly increased since the industrial revolution and continues to increase as more of the world becomes dependent upon fossil fuels for important applications like transportation and power production. In a general case, whenever a fossil fuel is consumed, a primary product of a complete combustion reaction is carbon dioxide. In a more specific case, the collection, processing and combustion of coal for power production are one of the primary ways by which trace elements, such as arsenic and selenium, are released into the environment. All of these pollutants are known to have harmful effects, whether on the environment, human health or power production itself. Because of this there has been an increasing interest in studies related to combating these pollutants. Concerning CO2 emissions, recently there has been a significant amount of work related to CO2 capture. A promising method involves the encapsulation of CO2 into isoreticular metal-organic frameworks (IRMOFs). The effectiveness of IMROFs greatly depends on the choice of both metal and organic parts. Molecular simulations have been used in the past to aid in the design and characterization of new MOFs, in particular by generating an adsorption isotherm. However, these traditional simulation methods have several drawbacks. The method used in this thesis, namely expanded Wang-Landau, not only overcomes these drawbacks but provides access to all the thermodynamic properties relevant to the adsorption process through a solution thermodynamics approach. This is greatly beneficial, since an excellent way to characterize the performance of various MOFs is by comparing their desorption free energy, i.e., the energy it takes to regenerate a saturated MOF to prepare it for the next adsorption cycle. Expanded WL was used in the study of CO 2 adsorption into IRMOF-1, 8 and 10 at eight temperatures, spanning both the subcritical and supercritical regimes and the following were obtained

  1. Theoretical studies of oxides relevant to the combustion of fossil fuels

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Michael

    Anthropogenic pollution has greatly increased since the industrial revolution and continues to increase as more of the world becomes dependent upon fossil fuels for important applications like transportation and power production. In a general case, whenever a fossil fuel is consumed, a primary product of a complete combustion reaction is carbon dioxide. In a more specific case, the collection, processing and combustion of coal for power production are one of the primary ways by which trace elements, such as arsenic and selenium, are released into the environment. All of these pollutants are known to have harmful effects, whether on the environment, human health or power production itself. Because of this there has been an increasing interest in studies related to combating these pollutants. Concerning CO2 emissions, recently there has been a significant amount of work related to CO2 capture. A promising method involves the encapsulation of CO2 into isoreticular metal-organic frameworks (IRMOFs). The effectiveness of IMROFs greatly depends on the choice of both metal and organic parts. Molecular simulations have been used in the past to aid in the design and characterization of new MOFs, in particular by generating an adsorption isotherm. However, these traditional simulation methods have several drawbacks. The method used in this thesis, namely expanded Wang-Landau, not only overcomes these drawbacks but provides access to all the thermodynamic properties relevant to the adsorption process through a solution thermodynamics approach. This is greatly beneficial, since an excellent way to characterize the performance of various MOFs is by comparing their desorption free energy, i.e., the energy it takes to regenerate a saturated MOF to prepare it for the next adsorption cycle. Expanded WL was used in the study of CO 2 adsorption into IRMOF-1, 8 and 10 at eight temperatures, spanning both the subcritical and supercritical regimes and the following were obtained

  2. Performance study of a solid oxide fuel cell and gas turbine hybrid system designed for methane operating with non-designed fuels

    NASA Astrophysics Data System (ADS)

    Li, Yang; Weng, Yiwu

    This paper presents an analysis of the fuel flexibility of a methane-based solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system. The simulation models of the system are mathematically defined. Special attention is paid to the development of an SOFC thermodynamic model that allows for the calculation of radial temperature gradients. Based on the simulation model, the new design point of system for new fuels is defined first; the steady-state performance of the system fed by different fuels is then discussed. When the hybrid system operates with hydrogen, the net power output at the new design point will decrease to 70% of the methane, while the design net efficiency will decrease to 55%. Similar to hydrogen, the net output power of the ethanol-fueled system will decrease to 88% of the methane value due to the lower cooling effect of steam reforming. However, the net efficiency can remain at 61% at high level due to increased heat recuperation from exhaust gas. To increase the power output of the hybrid system operating with non-design fuels without changing the system configuration, three different measures are introduced and investigated in this paper. The introduced measures can increase the system net power output operating with hydrogen to 94% of the original value at the cost of a lower efficiency of 45%.

  3. Fuel system design concepts for broad property fuels

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.

    1984-01-01

    The results of a study assessing the impact of using jet fuel with relaxed specification properties on an aircraft fuel system are given. The study objectives were to identify credible values for specific fuel properties which might be relaxed, to evolve advanced fuel system designs for airframe and engines which would permit use of the specified relaxed properties fuels, and to evaluate performance of the candidate advanced fuel systems and the relaxed property fuels in a typical transport aircraft. The study used, as a baseline, the fuel system incorporated in the Lockheed Tristar. This aircraft is powered by three RB.211-524 Rolls-Royce engines and incorporates a Pratt and Whitney ST6C-421 auxiliary power unit for engine starting and inflight emergency electrical power. The fuel property limits examined are compared with commercial Jet A kerosene and the NASA RFP fuel properties. A screening of these properties established that a higher freezing point and a lower thermal stability would impact fuel system design more significantly than any of the other property changes. Three candidate fuel systems which combine the ability to operate with fuels having both a high freeze point and a low thermal stability are described. All candidates employ bleed air to melt fuel freeze-out prior to starting the APU or an inoperable engine. The effects of incorporating these systems on aircraft weight and engine specific fuel consumption are given.

  4. Study of organic compounds evolved during the co-firing of coal and refuse derived fuel using TG/MS

    SciTech Connect

    Puroshothama, Shobha; Lu, R.; Yang, Xiaodong

    1996-10-01

    The evolution of organic compounds during the combustion of carbonaceous fuel coupled with solid waste disposal and limited landfill space has been a cause for concern. Co-firing high sulfur coal with refuse derived fuel seems an attractive alternative technique to tackle the dual problem of controlling SO{sub x} emissions as well as those of the chlorinated organic toxins. The TG serves to emulate the conditions of the fluidized bed combustor and the MS serves as the detector for evolved gases. This versatile combination is used to study the decomposition pathway as well as predict the conditions at which various compounds are formed and may serve as a means of reducing the formation of these chlorinated organic compounds.

  5. Experimental Study of Injection Characteristics of a Multi-hole port injector on various Fuel Injection pressures and Temperatures

    NASA Astrophysics Data System (ADS)

    Movahednejad, E.; Ommi, F.; Nekofar, K.

    2013-04-01

    The structures of the port injector spray dominates the mixture preparation process and strongly affect the subsequent engine combustion characteristics over a wide range of operating conditions in port-injection gasoline engines. All these spray characteristics are determined by particular injector design and operating conditions. In this paper, an experimental study is made to characterize the breakup mechanism and spray characteristics of a injector with multi-disc nozzle (SAGEM,D2159MA). A comparison was made on injection characteristics of the multi-hole injectors and its effects on various fuel pressure and temperature. The distributions of the droplet size and velocity and volume flux were characterized using phase Doppler anemometry (PDA) technique. Through this work, it was found that the injector produces a finer spray with a wide spray angle in higher fuel pressure and temperature.

  6. A study on synthesis of energy fuel from waste plastic and assessment of its potential as an alternative fuel for diesel engines.

    PubMed

    Kaimal, Viswanath K; Vijayabalan, P

    2016-05-01

    The demand for plastic is ever increasing and has produced a huge amount of plastic waste. The management and disposal of plastic waste have become a major concern, especially in developing cities. The idea of waste to energy recovery is one of the promising techniques used for managing the waste plastic. This paper assesses the potential of using Waste Plastic Oil (WPO), synthesized using pyrolysis of waste plastic, as an alternative for diesel fuel. In this research work, the performance and emission characteristics of a single cylinder diesel engine fuelled with WPO and its blends with diesel are studied. In addition to neat plastic oil, three blends (PO25, PO50 and PO75) were prepared on a volumetric basis and the engine was able to run on neat plastic oil. Brake thermal efficiency of blends was lower compared to diesel, but PO25 showed similar performance to that of diesel. The emissions were reduced considerably while using blends when compared to neat plastic oil. The smoke and NOX were reduced by 22% and 17.8% respectively for PO25 than that of plastic oil.

  7. A study on synthesis of energy fuel from waste plastic and assessment of its potential as an alternative fuel for diesel engines.

    PubMed

    Kaimal, Viswanath K; Vijayabalan, P

    2016-05-01

    The demand for plastic is ever increasing and has produced a huge amount of plastic waste. The management and disposal of plastic waste have become a major concern, especially in developing cities. The idea of waste to energy recovery is one of the promising techniques used for managing the waste plastic. This paper assesses the potential of using Waste Plastic Oil (WPO), synthesized using pyrolysis of waste plastic, as an alternative for diesel fuel. In this research work, the performance and emission characteristics of a single cylinder diesel engine fuelled with WPO and its blends with diesel are studied. In addition to neat plastic oil, three blends (PO25, PO50 and PO75) were prepared on a volumetric basis and the engine was able to run on neat plastic oil. Brake thermal efficiency of blends was lower compared to diesel, but PO25 showed similar performance to that of diesel. The emissions were reduced considerably while using blends when compared to neat plastic oil. The smoke and NOX were reduced by 22% and 17.8% respectively for PO25 than that of plastic oil. PMID:26969288

  8. Field-to-Fuel Performance Testing of Lignocellulosic Feedstocks: An Integrated Study of the Fast Pyrolysis/Hydrotreating Pathway

    SciTech Connect

    Howe, Daniel T.; Westover, Tyler; Carpenter, Daniel; Santosa, Daniel M.; Emerson, Rachel; Deutch, Steve; Starace, Anne; Kutnyakov, Igor V.; Lukins, Craig D.

    2015-05-21

    Feedstock composition can affect final fuel yields and quality for the fast pyrolysis and hydrotreatment upgrading pathway. However, previous studies have focused on individual unit operations rather than the integrated system. In this study, a suite of six pure lignocellulosic feedstocks (clean pine, whole pine, tulip poplar, hybrid poplar, switchgrass, and corn stover) and two blends (equal weight percentages whole pine/tulip poplar/switchgrass and whole pine/clean pine/hybrid poplar) were prepared and characterized at Idaho National Laboratory. These blends then underwent fast pyrolysis at the National Renewable Energy Laboratory and hydrotreatment at Pacific Northwest National Laboratory. Although some feedstocks showed a high fast pyrolysis bio-oil yield such as tulip poplar at 57%, high yields in the hydrotreater were not always observed. Results showed overall fuel yields of 15% (switchgrass), 18% (corn stover), 23% (tulip poplar, Blend 1, Blend 2), 24% (whole pine, hybrid poplar) and 27% (clean pine). Simulated distillation of the upgraded oils indicated that the gasoline fraction varied from 39% (clean pine) to 51% (corn stover), while the diesel fraction ranged from 40% (corn stover) to 46% (tulip poplar). Little variation was seen in the jet fuel fraction at 11 to 12%. Hydrogen consumption during hydrotreating, a major factor in the economic feasibility of the integrated process, ranged from 0.051 g/g dry feed (tulip poplar) to 0.070 g/g dry feed (clean pine).

  9. Are today's automotive technician students ready for the increased use of ethanol fuels: A study of students' perceptions of ethanol and the effects of E20

    NASA Astrophysics Data System (ADS)

    Mead, Gary R.

    As the price of petroleum rises, the use of alternative fuels such as ethanol will continue to increase. As ethanol use increases, consumers are asking automotive technicians questions about the fuel. But how much do automotive technicians know about ethanol? In order to answer this question, a study was conducted to describe automotive technician students' knowledge, attitudes, and perceptions of ethanol as a vehicle fuel. Automotive students were chosen because they will be tomorrow's generation of technicians who will be working on vehicles that have used ethanol fuels along with flex fuel vehicles. The students were selected from six two-year technical colleges located in southern Minnesota. The six schools were chosen because they are located in areas where ethanol use is prevalent. The study used a 33-question pencil-and-paper survey to measure 184 automotive students' perceptions of ethanol. The survey revealed that students' knowledge of ethanol is very superficial. They know well advertised terms and facts, but lack an in-depth knowledge of the fuel. Also, it was discovered that several myths about ethanol still exist. Because of the lack of knowledge on technical aspects of the fuel, it is recommended that instructors in automotive programs incorporate a one to two hour class covering ethanol fuels into their courses. The second part of this study was a review of several material compatibility studies conducted at Minnesota State University, Mankato on 20% ethanol blends. The studies were conducted on fuel system rubbers, plastics, and metals. Minnesota recently enacted a law that will require all gasoline sold in the state to contain 20% ethanol. These studies were reviewed to see if 20% ethanol, E20, will cause any vehicle fuel system problems that automotive technicians should know about. After reviewing the studies it was determined that the likelihood of fuel system problems from E20 would be very small and isolated. Even though the potential for

  10. Outlook for alternative transportation fuels

    SciTech Connect

    Gushee, D.E.

    1996-12-31

    This presentation provides a brief review of regulatory issues and Federal programs regarding alternative fuel use in automobiles. A number of U.S. DOE initiatives and studies aimed at increasing alternative fuels are outlined, and tax incentives in effect at the state and Federal levels are discussed. Data on alternative fuel consumption and alternative fuel vehicle use are also presented. Despite mandates, tax incentives, and programs, it is concluded alternative fuels will have minimal market penetration. 7 refs., 5 tabs.

  11. Study of CANDU thorium-based fuel cycles by deterministic and Monte Carlo methods

    SciTech Connect

    Nuttin, A.; Guillemin, P.; Courau, T.; Marleau, G.; Meplan, O.; David, S.; Michel-Sendis, F.; Wilson, J. N.

    2006-07-01

    In the framework of the Generation IV forum, there is a renewal of interest in self-sustainable thorium fuel cycles applied to various concepts such as Molten Salt Reactors [1, 2] or High Temperature Reactors [3, 4]. Precise evaluations of the U-233 production potential relying on existing reactors such as PWRs [5] or CANDUs [6] are hence necessary. As a consequence of its design (online refueling and D{sub 2}O moderator in a thermal spectrum), the CANDU reactor has moreover an excellent neutron economy and consequently a high fissile conversion ratio [7]. For these reasons, we try here, with a shorter term view, to re-evaluate the economic competitiveness of once-through thorium-based fuel cycles in CANDU [8]. Two simulation tools are used: the deterministic Canadian cell code DRAGON [9] and MURE [10], a C++ tool for reactor evolution calculations based on the Monte Carlo code MCNP [11]. (authors)

  12. Additive Manufacturing of a Microbial Fuel Cell--A detailed study.

    PubMed

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-01-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m(-3) per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments.

  13. Additive Manufacturing of a Microbial Fuel Cell—A detailed study

    PubMed Central

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-01-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m−3 per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments. PMID:26611142

  14. Additive Manufacturing of a Microbial Fuel Cell—A detailed study

    NASA Astrophysics Data System (ADS)

    Calignano, Flaviana; Tommasi, Tonia; Manfredi, Diego; Chiolerio, Alessandro

    2015-11-01

    In contemporary society we observe an everlasting permeation of electron devices, smartphones, portable computing tools. The tiniest living organisms on Earth could become the key to address this challenge: energy generation by bacterial processes from renewable stocks/waste through devices such as microbial fuel cells (MFCs). However, the application of this solution was limited by a moderately low efficiency. We explored the limits, if any, of additive manufacturing (AM) technology to fabricate a fully AM-based powering device, exploiting low density, open porosities able to host the microbes, systems easy to fuel continuously and to run safely. We obtained an optimal energy recovery close to 3 kWh m-3 per day that can power sensors and low-power appliances, allowing data processing and transmission from remote/harsh environments.

  15. Study of LH2-fueled topping cycle engine for aircraft propulsion

    NASA Technical Reports Server (NTRS)

    Turney, G. E.; Fishbach, L. H.

    1983-01-01

    An analytical investigation was made of a topping cycle aircraft engine system which uses a cryogenic fuel. This system consists of a main turboshaft engine which is mechanically coupled (by cross-shafting) to a topping loop which augments the shaft power output of the system. The thermodynamic performance of the topping cycle engine was analyzed and compared with that of a reference (conventional-type) turboshaft engine. For the cycle operating conditions selected, the performance of the topping cycle engine in terms of brake specific fuel consumption (bsfc) was determined to be about 12 percent better than that of the reference turboshaft engine. Engine weights were estimated for both the topping cycle engine and the reference turboshaft engine. These estimates were based on a common shaft power output for each engine. Results indicate that the weight of the topping cycle engine is comparable to that of the reference turboshaft engine.

  16. Preliminary Study of the Fuel Saving Potential of Regenerative Turbofans for Commercial Subsonic Transports. [engine tests

    NASA Technical Reports Server (NTRS)

    Kraft, G. A.

    1975-01-01

    The fuel savings potential of regenerative turbofans was calculated and compared with that of a reference turbofan. At the design altitude of 10.67 km and Mach 0.80, the turbine-inlet-temperature of the regenerative turbofan was fixed at 1700 K while the overall pressure ratio was varied from 10 to 20. The fan pressure ratio was fixed at 1.6 and the bypass ratio varied from 8 to 10. The heat exchanger design parameters such as pressure drop and effectiveness varied from 4 to 8 percent and from 0.80 to 0.90, respectively. Results indicate a fuel savings due to regeneration of 4.1 percent and no change in takeoff gross weight.

  17. Study of the feasibility of the commercial production of refuse derived fuel

    SciTech Connect

    Not Available

    1986-01-01

    In Nebraska, approximately 3.5 pounds of domestic waste is generated per person per day. Most of this waste is not recycled but is being disposed of in either a landfill or an open dump. In the state of Nebraska there are 359 dumps being used by municipalities of less than 5000 people which have been exempt from state control since 1972 as the result of implementation of the Whitney Amendment. A survey at 68 of the 359 sites showed that most of the sites were not supervised and were engaging in activities which are either strictly regulated or prohibited in the state's 63 licensed landfills. The need does exist to develop a different method of disposing of municipal waste. Converting the refuse into biomass pellets would be one way to address this need. It is proposed to establish a business to be incorporated under the name of Progressive Fuels, Inc. and to manufacture refuse derived fuel (RDF) in northeast Nebraska.

  18. Chamber studies on nonvented decorative fireplaces using liquid or gelled ethanol fuel.

    PubMed

    Schripp, Tobias; Salthammer, Tunga; Wientzek, Sebastian; Wensing, Michael

    2014-03-18

    Decorative ethanol fireplaces are becoming more and more commonly used in many different countries. These fireplaces are constructed such that they have no fume extraction system, and so all of the gases from combustion, volatile organic compounds, and particulate emissions are released into the room. In order to determine the release behavior and the chemical composition of the emissions, a variety of combinations of ethanol fireplaces and fuels were examined in a 48 m(3) emission test chamber under typical living room environmental conditions. Four ethanol fireplaces with 8 different fuels (3 liquid samples, 5 gel-type samples) were tested. The ventilation conditions were set up corresponding to the manufacturers' recommendations and DIN 4734-1. The air concentrations in the chamber were evaluated based on guideline values for indoor air. Of the combustion gases examined, the quantity of carbon dioxide and nitrogen dioxide in particular were close to or even above the guideline values in many cases. A release of components of the fuel (e.g., the denaturing substances) was also detected in the chamber air. In two experiments, a benzene concentration of over 12 ppb and an increased formaldehyde concentration (>0.1 ppm) were identified in the chamber air. The ethanol fireplaces were--irrespective of the type of fuel used--strong sources of fine and ultrafine particles. Overall, ethanol fireplaces have a considerable influence on the quality of the indoor air due to the lack of ventilation. This aspect should--in addition to fire protection--be properly considered when using such devices. PMID:24517295

  19. Chamber studies on nonvented decorative fireplaces using liquid or gelled ethanol fuel.

    PubMed

    Schripp, Tobias; Salthammer, Tunga; Wientzek, Sebastian; Wensing, Michael

    2014-03-18

    Decorative ethanol fireplaces are becoming more and more commonly used in many different countries. These fireplaces are constructed such that they have no fume extraction system, and so all of the gases from combustion, volatile organic compounds, and particulate emissions are released into the room. In order to determine the release behavior and the chemical composition of the emissions, a variety of combinations of ethanol fireplaces and fuels were examined in a 48 m(3) emission test chamber under typical living room environmental conditions. Four ethanol fireplaces with 8 different fuels (3 liquid samples, 5 gel-type samples) were tested. The ventilation conditions were set up corresponding to the manufacturers' recommendations and DIN 4734-1. The air concentrations in the chamber were evaluated based on guideline values for indoor air. Of the combustion gases examined, the quantity of carbon dioxide and nitrogen dioxide in particular were close to or even above the guideline values in many cases. A release of components of the fuel (e.g., the denaturing substances) was also detected in the chamber air. In two experiments, a benzene concentration of over 12 ppb and an increased formaldehyde concentration (>0.1 ppm) were identified in the chamber air. The ethanol fireplaces were--irrespective of the type of fuel used--strong sources of fine and ultrafine particles. Overall, ethanol fireplaces have a considerable influence on the quality of the indoor air due to the lack of ventilation. This aspect should--in addition to fire protection--be properly considered when using such devices.

  20. Parametric study of natural circulation flow in molten salt fuel in molten salt reactor

    NASA Astrophysics Data System (ADS)

    Pauzi, Anas Muhamad; Cioncolini, Andrea; Iacovides, Hector

    2015-04-01

    The Molten Salt Reactor (MSR) is one of the most promising system proposed by Generation IV Forum (GIF) for future nuclear reactor systems. Advantages of the MSR are significantly larger compared to other reactor system, and is mainly achieved from its liquid nature of fuel and coolant. Further improvement to this system, which is a natural circulating molten fuel salt inside its tube in the reactor core is proposed, to achieve advantages of reducing and simplifying the MSR design proposed by GIF. Thermal hydraulic analysis on the proposed system was completed using a commercial computation fluid dynamics (CFD) software called FLUENT by ANSYS Inc. An understanding on theory behind this unique natural circulation flow inside the tube caused by fission heat generated in molten fuel salt and tube cooling was briefly introduced. Currently, no commercial CFD software could perfectly simulate natural circulation flow, hence, modeling this flow problem in FLUENT is introduced and analyzed to obtain best simulation results. Results obtained demonstrate the existence of periodical transient nature of flow problem, hence improvements in tube design is proposed based on the analysis on temperature and velocity profile. Results show that the proposed system could operate at up to 750MW core power, given that turbulence are enhanced throughout flow region, and precise molten fuel salt physical properties could be defined. At the request of the authors and the Proceedings Editor the name of the co-author Andrea Cioncolini was corrected from Andrea Coincolini. The same name correction was made in the Acknowledgement section on page 030004-10 and in reference number 4. The updated article was published on 11 May 2015.