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Sample records for generator heat source

  1. Safe radioisotope thermoelectric generators and heat sources for space applications

    NASA Astrophysics Data System (ADS)

    O'Brien, R. C.; Ambrosi, R. M.; Bannister, N. P.; Howe, S. D.; Atkinson, H. V.

    2008-07-01

    Several isotopes are examined as alternatives to 238Pu that is traditionally used in radioisotope thermoelectric generators (RTGs) and heating units (RHUs). The radioisotopes discussed include 241Am, 208Po, 210Po, and 90Sr. The aim of this study is to facilitate the design of an RTG with a minimal radiation dose rate and mass including any required shielding. Applications of interest are primarily space and planetary exploration. In order to evaluate the properties of the alternative radioisotopes a Monte Carlo model was developed to examine the radiation protection aspect of the study. The thermodynamics of the power generation process is examined and possible materials for the housing and encapsulation of the radioisotopes are proposed. In this study we also present a historical review of radioisotope thermoelectric generators (RTGs) and the thermoelectric conversion mechanism in order to provide a direct comparison with the performance of our proposed alternative isotope systems.

  2. Milliwatt-generator heat source. Progress report, January-June 1983

    SciTech Connect

    Mershad, E.A.

    1983-09-20

    Progress is reported in the following: heat source shipments, reimbursable orders, hardware shipments, raw material qualification/procurement, DOE audit and milliwatt generator process review, surveillance capsule evaluations, pressure burst testing, and hardware fabrication and quality. (MHR)

  3. HEAT GENERATION

    DOEpatents

    Imhoff, D.H.; Harker, W.H.

    1963-12-01

    Heat is generated by the utilization of high energy neutrons produced as by nuclear reactions between hydrogen isotopes in a blanket zone containing lithium, a neutron moderator, and uranium and/or thorium effective to achieve multtplicatton of the high energy neutron. The rnultiplied and moderated neutrons produced react further with lithium-6 to produce tritium in the blanket. Thermal neutron fissionable materials are also produced and consumed in situ in the blanket zone. The heat produced by the aggregate of the various nuclear reactions is then withdrawn from the blanket zone to be used or otherwise disposed externally. (AEC)

  4. Micro- and Nanoscale Energetic Materials as Effective Heat Energy Sources for Enhanced Gas Generators.

    PubMed

    Kim, Sang Beom; Kim, Kyung Ju; Cho, Myung Hoon; Kim, Ji Hoon; Kim, Kyung Tae; Kim, Soo Hyung

    2016-04-13

    In this study, we systematically investigated the effect of micro- and nanoscale energetic materials in formulations of aluminum microparticles (Al MPs; heat source)/aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ∼0.3 m/s. However, the addition of Al MPs and Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ∼1.5 and ∼5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ∼0.6 L/s, which was significantly increased to ∼1.4 and ∼3.9 L/s by adding Al MPs and Al NPs, respectively, to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive Al MPs and NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were more effective than Al MPs in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ∼140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ∼50 ms for airbag inflation.

  5. Micro- and Nanoscale Energetic Materials as Effective Heat Energy Sources for Enhanced Gas Generators.

    PubMed

    Kim, Sang Beom; Kim, Kyung Ju; Cho, Myung Hoon; Kim, Ji Hoon; Kim, Kyung Tae; Kim, Soo Hyung

    2016-04-13

    In this study, we systematically investigated the effect of micro- and nanoscale energetic materials in formulations of aluminum microparticles (Al MPs; heat source)/aluminum nanoparticles (Al NPs; heat source)/copper oxide nanoparticles (CuO NPs; oxidizer) on the combustion and gas-generating properties of sodium azide microparticles (NaN3 MPs; gas-generating agent) for potential applications in gas generators. The burn rate of the NaN3 MP/CuO NP composite powder was only ∼0.3 m/s. However, the addition of Al MPs and Al NPs to the NaN3 MP/CuO NP matrix caused the rates to reach ∼1.5 and ∼5.3 m/s, respectively. In addition, the N2 gas volume flow rate generated by the ignition of the NaN3 MP/CuO NP composite powder was only ∼0.6 L/s, which was significantly increased to ∼1.4 and ∼3.9 L/s by adding Al MPs and Al NPs, respectively, to the NaN3 MP/CuO NP composite powder. This suggested that the highly reactive Al MPs and NPs, with the assistance of CuO NPs, were effective heat-generating sources enabling the complete thermal decomposition of NaN3 MPs upon ignition. Al NPs were more effective than Al MPs in the gas generators because of the increased reactivity induced by the reduced particle size. Finally, we successfully demonstrated that a homemade airbag with a specific volume of ∼140 mL could be rapidly and fully inflated by the thermal activation of nanoscale energetic material-added gas-generating agents (i.e., NaN3 MP/Al NP/CuO NP composites) within the standard time of ∼50 ms for airbag inflation. PMID:27007287

  6. Radioisotopic heat source

    DOEpatents

    Jones, G.J.; Selle, J.E.; Teaney, P.E.

    1975-09-30

    Disclosed is a radioisotopic heat source and method for a long life electrical generator. The source includes plutonium dioxide shards and yttrium or hafnium in a container of tantalum-tungsten-hafnium alloy, all being in a nickel alloy outer container, and subjected to heat treatment of from about 1570$sup 0$F to about 1720$sup 0$F for about one h. (auth)

  7. Generation of Acoustic-Gravity Waves in Ionospheric HF Heating Experiments: Simulating Large-Scale Natural Heat Sources

    NASA Astrophysics Data System (ADS)

    Pradipta, Rezy

    In this thesis, we investigate the potential role played by large-scale anomalous heat sources (e.g. prolonged heat wave events) in generating acoustic-gravity waves (AGWs) that might trigger widespread plasma turbulence in the ionospheric layer. The main hypothesis is that, the thermal gradients associated with the heat wave fronts could act as a source of powerful AGW capable of triggering ionospheric plasma turbulence over extensive areas. In our investigations, first we are going to examine a case study of the summer 2006 North American heat wave event. Our examination of GPS-derived total electron content (TEC) data over the North American sector reveals a quite noticeable increase in the level of daily plasma density fluctuations during the summer 2006 heat wave period. Comparison with the summer 2005 and summer 2007 data further confirms that the observed increase of traveling ionospheric disturbances (TIDs) during the summer 2006 heat wave period was not simply a regular seasonal phenomenon. Furthermore, a series of field experiments had been carried out at the High-frequency Active Auroral Research Program (HAARP) facility in order to physically simulate the process of AGW/TID generation by large-scale thermal gradients in the ionosphere. In these ionospheric HF heating experiments, we create some time-varying artificial thermal gradients at an altitude of 200--300 km above the Earth's surface using vertically-transmitted amplitude-modulated 0-mode HF heater waves. For our experiments, a number of radio diagnostic instruments had been utilized to detect the characteristic signatures of heater-generated AGW/TID. So far, we have been able to obtain several affirmative indications that some artificial AGW/TID are indeed being radiated out from the heated plasma volume during the HAARP-AGW experiments. Based on the experimental evidence, we may conclude that it is certainly quite plausible for large-scale thermal gradients associated with severe heat wave

  8. ELF/VLF wave generation from the beating of two HF ionospheric heating sources

    NASA Astrophysics Data System (ADS)

    Cohen, M. B.; Moore, R. C.; Golkowski, M.; Lehtinen, N. G.

    2012-12-01

    It is well established that Extremely Low Frequency (ELF, 0.3-3 kHz) and Very Low Frequency (VLF, 3-30 kHz) radio waves can be generated via modulated High Frequency (HF, 3-10 MHz) heating of the lower ionosphere (60-100 km). The ionospheric absorption of HF power modifies the conductivity of the lower ionosphere, which in the presence of natural currents such as the auroral electrojet, creates an `antenna in the sky.' We utilize a theoretical model of the HF to ELF/VLF conversion and the ELF/VLF propagation, and calculate the amplitudes of the generated ELF/VLF waves when two HF heating waves, separated by the ELF/VLF frequency, are transmitted from two adjacent locations. The resulting ELF/VLF radiation pattern exhibits a strong directional dependence (as much as 15 dB) that depends on the physical spacing of the two HF sources. This beat wave source can produce signals 10-20 dB stronger than those generated using amplitude modulation, particularly for frequencies greater than 5-10 kHz. We evaluate recent suggestions that beating two HF waves generates ELF/VLF waves in the F-region (>150 km), and conclude that those experimental results may have misinterpreted, and can be explained strictly by the much more well established D region mechanism.

  9. Neutron generator for BNCT based on high current ECR ion source with gyrotron plasma heating.

    PubMed

    Skalyga, V; Izotov, I; Golubev, S; Razin, S; Sidorov, A; Maslennikova, A; Volovecky, A; Kalvas, T; Koivisto, H; Tarvainen, O

    2015-12-01

    BNCT development nowadays is constrained by a progress in neutron sources design. Creation of a cheap and compact intense neutron source would significantly simplify trial treatments avoiding use of expensive and complicated nuclear reactors and accelerators. D-D or D-T neutron generator is one of alternative types of such sources for. A so-called high current quasi-gasdynamic ECR ion source with plasma heating by millimeter wave gyrotron radiation is suggested to be used in a scheme of D-D neutron generator in the present work. Ion source of that type was developed in the Institute of Applied Physics of Russian Academy of Sciences (Nizhny Novgorod, Russia). It can produce deuteron ion beams with current density up to 700-800 mA/cm(2). Generation of the neutron flux with density at the level of 7-8·10(10) s(-1) cm(-2) at the target surface could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV. Estimations show that it is enough for formation of epithermal neutron flux with density higher than 10(9) s(-1) cm(-2) suitable for BNCT. Important advantage of described approach is absence of Tritium in the scheme. First experiments performed in pulsed regime with 300 mA, 45 kV deuteron beam directed to D2O target demonstrated 10(9) s(-1) neutron flux. This value corresponds to theoretical estimations and proofs prospects of neutron generator development based on high current quasi-gasdynamic ECR ion source. PMID:26302662

  10. Neutron generator for BNCT based on high current ECR ion source with gyrotron plasma heating.

    PubMed

    Skalyga, V; Izotov, I; Golubev, S; Razin, S; Sidorov, A; Maslennikova, A; Volovecky, A; Kalvas, T; Koivisto, H; Tarvainen, O

    2015-12-01

    BNCT development nowadays is constrained by a progress in neutron sources design. Creation of a cheap and compact intense neutron source would significantly simplify trial treatments avoiding use of expensive and complicated nuclear reactors and accelerators. D-D or D-T neutron generator is one of alternative types of such sources for. A so-called high current quasi-gasdynamic ECR ion source with plasma heating by millimeter wave gyrotron radiation is suggested to be used in a scheme of D-D neutron generator in the present work. Ion source of that type was developed in the Institute of Applied Physics of Russian Academy of Sciences (Nizhny Novgorod, Russia). It can produce deuteron ion beams with current density up to 700-800 mA/cm(2). Generation of the neutron flux with density at the level of 7-8·10(10) s(-1) cm(-2) at the target surface could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV. Estimations show that it is enough for formation of epithermal neutron flux with density higher than 10(9) s(-1) cm(-2) suitable for BNCT. Important advantage of described approach is absence of Tritium in the scheme. First experiments performed in pulsed regime with 300 mA, 45 kV deuteron beam directed to D2O target demonstrated 10(9) s(-1) neutron flux. This value corresponds to theoretical estimations and proofs prospects of neutron generator development based on high current quasi-gasdynamic ECR ion source.

  11. Heat generation and neutron beam characteristics in a high power pulsed spallation neutron source

    SciTech Connect

    Jerng, D.W.; Carpenter, J.M.

    1996-11-01

    In the course of conceptual design of a high power pulsed spallation source, a Monte Carlo model was developed for heat generation and neutronics studies. In this paper, we present two sets of results. The first set of calculations was performed with a simple target model to investigate general characteristics of power distribution and neutron production with various proton energies ranging from 0.8 to 12 GeV. The second set was performed with a realistic target model including major components of the target system to provide basic parameters for engineering design of a high power pulsed spallation source. Calculated results generally confirm that higher proton energy provides and advantage in target cooling system requirements and yet somewhat lower neutron beam intensity as a counter effect. The heat generation in the systems surrounding the target was investigated in detail and found to have important variation with position and according to proton beam energy. Calculations of the neutron currents from the moderators showed that the neutron beam intensity from moderators in the front region of the target decreased fro higher proton energy while that from moderators in the back region of the target remained almost unchanged.

  12. Assembly of radioisotope heat sources and thermoelectric generators for Galileo and Ulysses missions

    NASA Astrophysics Data System (ADS)

    Amos, Wayne R.; Goebel, Charles J.

    The processes and facilities for assembling General-Purpose Heat Sources (GPHS) and assembling and testing GPHS radioisotope thermoelectric generators (RTGs) are discussed. Each RTG contains 18 GPHS modules and was designed to produce approximately 285 We. Five of these RTGs were successfully assembled and tested. Two are providing spacecraft power for NASA's Galileo mission to Jupiter. One RTG will provide spacecraft power for the Joint NASA/ESA, Ulysses mission to study the polar regions of the sun. One RTG was assembled and tested to serve as the common spare for both missions, while the fifth RTG serves as the nonflight qualification unit and is undergoing long-term life tests in a simulated space environment.

  13. The General-Purpose Heat Source Radioisotope Thermoelectric Generator: A Truly General-Purpose Space RTG

    NASA Astrophysics Data System (ADS)

    Bennett, Gary L.; Lombardo, James J.; Hemler, Richard J.; Silverman, Gil; Whitmore, C. W.; Amos, Wayne R.; Johnson, E. W.; Zocher, Roy W.; Hagan, James C.; Englehart, Richard W.

    2008-01-01

    The General-Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) was developed for the originally planned International Solar Polar Mission (ISPM). [ISPM would later, with the elimination of the NASA spacecraft, become the Ulysses mission.] At 300 We beginning-of-life (BOL) power, the GPHS-RTG was the most powerful RTG with the highest specific power (5.3 We/kg) of any space RTG. These improved performance attributes of the GPHS-RTG made it attractive for use on the Galileo mission. Subsequently, the GPHS-RTG was selected to power the Cassini spacecraft, which is currently orbiting Saturn, and the New Horizons spacecraft which is on its way to Pluto. Truly, the GPHS-RTG is a ``general-purpose'' space RTG.

  14. Certification testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-09-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping counter is a Type B packaging currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to normal and hypothetical accident environments defined in Title 10 of the Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this packaging design. This report documents the testing portion of the design verification. Six tests were conducted on a prototype package: a water spray test, a 4-foot normal conditions drop test, a 30-foot drop test, a 40-inch puncture test, a 30-minute thermal test, and an 8-hour immersion test.

  15. Structural testing of the Los Alamos National Laboratory Heat Source/Radioisotopic Thermoelectric Generator shipping container

    SciTech Connect

    Bronowski, D.R.; Madsen, M.M.

    1991-06-01

    The Heat Source/Radioisotopic Thermoelectric Generator shipping container is a Type B packaging design currently under development by Los Alamos National Laboratory. Type B packaging for transporting radioactive material is required to maintain containment and shielding after being exposed to the normal and hypothetical accident environments defined in Title 10 Code of Federal Regulations Part 71. A combination of testing and analysis is used to verify the adequacy of this package design. This report documents the test program portion of the design verification, using several prototype packages. Four types of testing were performed: 30-foot hypothetical accident condition drop tests in three orientations, 40-inch hypothetical accident condition puncture tests in five orientations, a 21 psi external overpressure test, and a normal conditions of transport test consisting of a water spray and a 4 foot drop test. 18 refs., 104 figs., 13 tabs.

  16. Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator Programs

    SciTech Connect

    Gabriel, D. M.; Miller, G. D.; Bohne, W. A.

    1995-03-16

    The purpose of this document is to serve as the Quality Assurance Plan for Heat Source/Radioisotope Thermoelectric Generator (HS/RTG) programs performed at EG&G Mound Applied Technologies. As such, it identifies and describes the systems and activities in place to support the requirements contained in DOE Order 5700.6C as reflected in MD-10334, Mound Quality Policy and Responsibilities and the DOE/RPSD supplement, OSA/PQAR-1, Programmatic Quality Assurance Requirements for Space and Terrestrial Nuclear Power Systems. Unique program requirements, including additions, modifications, and exceptions to these quality requirements, are contained in the appendices of this plan. Additional appendices will be added as new programs and activities are added to Mound's HS/RTG mission assignment.

  17. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy`s (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE`s Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford`s MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford`s calculations assume five times the GPHS inventory of that assumed for Mound.

  18. A shielded storage and processing facility for radioisotope thermoelectric generator heat source production

    SciTech Connect

    Sherrell, D.L.

    1992-06-01

    This report discusses a shielded storage rack which has been installed as part of the Radioisotope Power Systems Facility (RPSF) at the US Department of Energy's (DOE) Hanford Site in Washington State. The RPSF is designed to replace an existing facility at DOE's Mound Site near Dayton, Ohio, where General Purpose Heat Source (GPHS) modules are currently assembled and installed into Radioisotope Thermoelectric Generators (RTG). The overall design goal of the RPSF is to increase annual production throughput, while at the same time reducing annual radiation exposure to personnel. The shield rack design successfully achieved this goal for the Module Reduction and Monitoring Facility (MRMF), which process and stores assembled GPHS modules, prior to their installation into RTGS. The shield rack design is simple and effective, with the result that background radiation levels within Hanford's MRMF room are calculated at just over three percent of those typically experienced during operation of the existing MRMF at Mound, despite the fact that Hanford's calculations assume five times the GPHS inventory of that assumed for Mound.

  19. Dual source heat pump

    DOEpatents

    Ecker, Amir L.; Pietsch, Joseph A.

    1982-01-01

    What is disclosed is a heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating the fluid in heat exchange relationship with a refrigerant fluid; at least two refrigerant heat exchangers, one for effecting heat exchange with the fluid and a second for effecting heat exchange between refrigerant and a heat exchange fluid and the ambient air; a compressor for efficiently compressing the refrigerant; at least one throttling valve for throttling liquid refrigerant; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circulating device and heat exchange fluid circuit for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and direction of flow of the refrigerant therethrough for selecting a particular mode of operation. The heat exchange fluid provides energy for defrosting the second heat exchanger when operating in the air source mode and also provides a alternate source of heat.

  20. Generation of Large-scale Thermospheric Disturbances and Thermosphere Heating by Infrasonic Waves Propagated from Tropospheric Sources

    NASA Astrophysics Data System (ADS)

    Kshevetskii, Sergey; Gavrilov, Nikolay; Karpov, Ivan; Kurdyaeva, Yuliya

    2015-04-01

    Meteorological processes in the lower atmosphere are the sources of excitation of acoustic gravity waves (AGWs). Fluctuations of atmospheric pressure within a wide range of frequencies, including infrasonic frequencies are evidence of these tropospheric wave sources. We simulate numerically the propagation of waves from tropospheric infrasound sources, and our study concerns the influences of these waves on the atmosphere. Numerical experiments have shown that the small-amplitude infrasound waves can propagate without striking manifestations up to the heights of about 100 km. Only waves propagating with a rather small angle to the vertical, penetrate the thermosphere and heat the thermosphere and generate internal gravity waves. Numerical experiments have revealed that tropospheric sources with spatial scales of several kilometers, are able to create wave disturbances in the thermosphere with spatial scales from tens to one thousand kilometers. The heating effect and generation of gravity waves is significant due to the fact that it accumulates. During one hour, the thermospheric temperature may change due to heating by infrasonic waves more than by 10 degrees. The simulations have shown that the infrasonic waves propagated upward may be a significant source of thermosphere heating.

  1. Advanced Soldier Thermoelectric Power System for Power Generation from Battlefield Heat Sources

    SciTech Connect

    Hendricks, Terry J.; Hogan, Tim; Case, Eldon D.; Cauchy, Charles J.

    2010-09-01

    The U.S. military uses large amounts of fuel during deployments and battlefield operations. This project sought to develop a lightweight, small form-factor, soldier-portable advanced thermoelectric (TE) system prototype to recover and convert waste heat from various deployed military equipment (i.e., diesel generators/engines, incinerators, vehicles, and potentially mobile kitchens), with the ultimate purpose of producing power for soldier battery charging, advanced capacitor charging, and other battlefield power applications. The technical approach employed microchannel technology, a unique “power panel” approach to heat exchange/TE system integration, and newly-characterized LAST (lead-antimony-silver-telluride) and LASTT (lead-antimony-silver-tin-telluride) TE materials segmented with bismuth telluride TE materials in designing a segmented-element TE power module and system. This project researched never-before-addressed system integration challenges (thermal expansion, thermal diffusion, electrical interconnection, thermal and electrical interfaces) of designing thin “power panels” consisting of alternating layers of thin, microchannel heat exchangers (hot and cold) sandwiching thin, segmented-element TE power generators. The TE properties, structurally properties, and thermal fatigue behavior of LAST and LASTT materials were developed and characterized such that the first segmented-element TE modules using LAST / LASTT materials were fabricated and tested at hot-side temperatures = 400 °C and cold-side temperatures = 40 °C. LAST / LASTT materials were successfully segmented with bismuth telluride and electrically interconnected with diffusion barrier materials and copper strapping within the module electrical circuit. A TE system design was developed to produce 1.5-1.6 kW of electrical energy using these new TE modules from the exhaust waste heat of 60-kW Tactical Quiet Generators as demonstration vehicles.

  2. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; Van Sant, J.H.

    1992-01-21

    This patent describes an isotopic heat source. It comprises; at least one isotopic fuel stack, comprising alternating layers of: thulium oxide; and a low atomic weight diluent for thulium oxide; a heat block defining holes into which the fuel stacks can be placed; at least one heat pipe for heat removal, with the heat pipe being positioned in the heat block in thermal connection with the fuel stack; and a structural container surrounding the heat block.

  3. Design and Numerical Simulation of a Symbiotic Thermoelectric Power Generation System Fed by a Low-Grade Heat Source

    NASA Astrophysics Data System (ADS)

    Faraji, Amir Yadollah; Singh, Randeep; Mochizuki, Masataka; Akbarzadeh, Aliakbar

    2014-06-01

    All liquid heating systems, including solar thermal collectors and fossil-fueled heaters, are designed to convert low-temperature liquid to high-temperature liquid. In the presence of low- and high-temperature fluids, temperature differences can be created across thermoelectric devices to produce electricity so that the heat dissipated from the hot side of a thermoelectric device will be absorbed by the cold liquid and this preheated liquid enters the heating cycle and increases the efficiency of the heater. Consequently, because of the avoidance of waste heat on the thermoelectric hot side, the efficiency of heat-to-electricity conversion with this configuration is better than that of conventional thermoelectric power generation systems. This research aims to design and analyze a thermoelectric power generation system based on the concept described above and using a low-grade heat source. This system may be used to generate electricity either in direct conjunction with any renewable energy source which produces hot water (solar thermal collectors) or using waste hot water from industry. The concept of this system is designated "ELEGANT," an acronym from "Efficient Liquid-based Electricity Generation Apparatus iNside Thermoelectrics." The first design of ELEGANT comprised three rectangular aluminum channels, used to conduct warm and cold fluids over the surfaces of several commercially available thermoelectric generator (TEG) modules sandwiched between the channels. In this study, an ELEGANT with 24 TEG modules, referred to as ELEGANT-24, has been designed. Twenty-four modules was the best match to the specific geometry of the proposed ELEGANT. The thermoelectric modules in ELEGANT-24 were electrically connected in series, and the maximum output power was modeled. A numerical model has been developed, which provides steady-state forecasts of the electrical output of ELEGANT-24 for different inlet fluid temperatures.

  4. Micro thrust and heat generator

    DOEpatents

    Garcia, E.J.

    1998-11-17

    A micro thrust and heat generator have a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachining techniques (LIGA). 30 figs.

  5. General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

    1996-07-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  6. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  7. Micro thrust and heat generator

    DOEpatents

    Garcia, Ernest J.

    1998-01-01

    A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator's ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachining techniques (LIGA).

  8. GPHS-RTG system explosion test direct course experiment 5000. [General Purpose Heat Source-Radioisotope Thermoelectric Generator

    SciTech Connect

    Not Available

    1984-03-01

    The General Purpose Heat Source-Radioisotope Thermoelectric Generator (GPHS-RTG) has been designed and is being built to provide electrical power for spacecrafts to be launched on the Space Shuttle. The objective of the RTG System Explosion Test was to expose a mock-up of the GPHS-RTG with a simulated heat source to the overpressure and impulse representative of a potential upper magnitude explosion of the Space Shuttle. The test was designed so that the heat source module would experience an overpressure at which the survival of the fuel element cladding would be expected to be marginal. Thus, the mock-up was placed where the predicted incident overpressure would be 1300 psi. The mock-up was mounted in an orientation representative of the launch configuration on the spacecraft to be used on the NASA Galileo Mission. The incident overpressure measured was in the range of 1400 to 2100 psi. The mock-up and simulated heat source were destroyed and only very small fragments were recovered. This damage is believed to have resulted from a combination of the overpressure and impact by very high velocity fragments from the ANFO sphere. Post-test analysis indicated that extreme working of the iridium clad material occurred, indicative of intensive impulsive loading on the metal.

  9. Multiple source heat pump

    DOEpatents

    Ecker, Amir L.

    1983-01-01

    A heat pump apparatus for conditioning a fluid characterized by a fluid handler and path for circulating a fluid in heat exchange relationship with a refrigerant fluid, at least three refrigerant heat exchangers, one for effecting heat exchange with the fluid, a second for effecting heat exchange with a heat exchange fluid, and a third for effecting heat exchange with ambient air; a compressor for compressing the refrigerant; at least one throttling valve connected at the inlet side of a heat exchanger in which liquid refrigerant is vaporized; a refrigerant circuit; refrigerant; a source of heat exchange fluid; heat exchange fluid circuit and pump for circulating the heat exchange fluid in heat exchange relationship with the refrigerant; and valves or switches for selecting the heat exchangers and directional flow of refrigerant therethrough for selecting a particular mode of operation. Also disclosed are a variety of embodiments, modes of operation, and schematics therefor.

  10. Impact of the High Flux Isotope Reactor HEU to LEU Fuel Conversion on Cold Source Nuclear Heat Generation Rates

    SciTech Connect

    Chandler, David

    2014-03-01

    Under the sponsorship of the US Department of Energy National Nuclear Security Administration, staff members at the Oak Ridge National Laboratory have been conducting studies to determine whether the High Flux Isotope Reactor (HFIR) can be converted from high enriched uranium (HEU) fuel to low enriched uranium (LEU) fuel. As part of these ongoing studies, an assessment of the impact that the HEU to LEU fuel conversion has on the nuclear heat generation rates in regions of the HFIR cold source system and its moderator vessel was performed and is documented in this report. Silicon production rates in the cold source aluminum regions and few-group neutron fluxes in the cold source moderator were also estimated. Neutronics calculations were performed with the Monte Carlo N-Particle code to determine the nuclear heat generation rates in regions of the HFIR cold source and its vessel for the HEU core operating at a full reactor power (FP) of 85 MW(t) and the reference LEU core operating at an FP of 100 MW(t). Calculations were performed with beginning-of-cycle (BOC) and end-of-cycle (EOC) conditions to bound typical irradiation conditions. Average specific BOC heat generation rates of 12.76 and 12.92 W/g, respectively, were calculated for the hemispherical region of the cold source liquid hydrogen (LH2) for the HEU and LEU cores, and EOC heat generation rates of 13.25 and 12.86 W/g, respectively, were calculated for the HEU and LEU cores. Thus, the greatest heat generation rates were calculated for the EOC HEU core, and it is concluded that the conversion from HEU to LEU fuel and the resulting increase of FP from 85 MW to 100 MW will not impact the ability of the heat removal equipment to remove the heat deposited in the cold source system. Silicon production rates in the cold source aluminum regions are estimated to be about 12.0% greater at BOC and 2.7% greater at EOC for the LEU core in comparison to the HEU core. Silicon is aluminum s major transmutation product and

  11. Radioisotopic heat source

    DOEpatents

    Sayell, E.H.

    1973-10-23

    A radioisotopic heat source is described which includes a core of heat productive, radioisotopic material, an impact resistant layer of graphite surrounding said core, and a shell of iridium metal intermediate the core and the impact layer. The source may also include a compliant mat of iridium between the core and the iridium shell, as well as an outer covering of iridium metal about the entire heat source. (Official Gazette)

  12. Organic Fluids and Passive Cooling in a Supercritical Rankine Cycle for Power Generation from Low Grade Heat Sources

    NASA Astrophysics Data System (ADS)

    Vidhi, Rachana

    Low grade heat sources have a large amount of thermal energy content. Due to low temperature, the conventional power generation technologies result in lower efficiency and hence cannot be used. In order to efficiently generate power, alternate methods need to be used. In this study, a supercritical organic Rankine cycle was used for heat source temperatures varying from 125°C to 200°C. Organic refrigerants with zero ozone depletion potential and their mixtures were selected as working fluid for this study while the cooling water temperature was changed from 10-25°C. Operating pressure of the cycle has been optimized for each fluid at every heat source temperature to obtain the highest thermal efficiency. Energy and exergy efficiencies of the thermodynamic cycle have been obtained as a function of heat source temperature. Efficiency of a thermodynamic cycle depends significantly on the sink temperature. At areas where water cooling is not available and ambient air temperature is high, efficient power generation from low grade heat sources may be a challenge. Use of passive cooling systems coupled with the condenser was studied, so that lower sink temperatures could be obtained. Underground tunnels, buried at a depth of few meters, were used as earth-air-heat-exchanger (EAHE) through which hot ambient air was passed. It was observed that the air temperature could be lowered by 5-10°C in the EAHE. Vertical pipes were used to lower the temperature of water by 5°C by passing it underground. Nocturnal cooling of stored water has been studied that can be used to cool the working fluid in the thermodynamic cycle. It was observed that the water temperature can be lowered by 10-20°C during the night when it is allowed to cool. The amount of water lost was calculated and was found to be approximately 0.1% over 10 days. The different passive cooling systems were studied separately and their effects on the efficiency of the thermodynamic cycle were investigated. They were

  13. The potential of high heat generating granites as EGS source to generate power and reduce CO2 emissions, western Arabian shield, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Chandrasekharam, D.; Lashin, A.; Al Arifi, N.; Al Bassam, A.; El Alfy, M.; Ranjith, P. G.; Varun, C.; Singh, H. K.

    2015-12-01

    Saudi Arabia's dependence on oil and gas to generate electricity and to desalinate sea water is widely perceived to be economically and politically unsustainable. A recent business as usual simulation concluded that the Kingdom would become an oil importer by 2038. There is an opportunity for the country to over come this problem by using its geothermal energy resources. The heat flow and heat generation values of the granites spread over a cumulative area of 161,467 sq. km and the regional stress regime over the western Saudi Arabian shield strongly suggest that this entire area is potential source of energy to support 1) electricity generation, 2) fresh water generation through desalination and 3) extensive agricultural activity for the next two decades. The country can adopt a policy to harness this vast untapped enhanced geothermal systems (EGS) to mitigate climate and fresh water related issues and increase the quantity of oil for export. The country has inherent expertise to develop this resource.

  14. Thulium-170 heat source

    DOEpatents

    Walter, Carl E.; Van Konynenburg, Richard; VanSant, James H.

    1992-01-01

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  15. Thulium-170 heat source

    SciTech Connect

    Walter, C.E.; Van Konynenburg, R.; VanSant, J.H.

    1990-09-06

    An isotopic heat source is formed using stacks of thin individual layers of a refractory isotopic fuel, preferably thulium oxide, alternating with layers of a low atomic weight diluent, preferably graphite. The graphite serves several functions: to act as a moderator during neutron irradiation, to minimize bremsstrahlung radiation, and to facilitate heat transfer. The fuel stacks are inserted into a heat block, which is encased in a sealed, insulated and shielded structural container. Heat pipes are inserted in the heat block and contain a working fluid. The heat pipe working fluid transfers heat from the heat block to a heat exchanger for power conversion. Single phase gas pressure controls the flow of the working fluid for maximum heat exchange and to provide passive cooling.

  16. Micro thrust and heat generator

    SciTech Connect

    Garcia, E.J.

    1995-12-31

    The present invention relates generally to micromachines such as microengines or micromotors. More specifically, the invention is directed to a micro rocket which functions as a source of heat and thrust, and utilizes chemical energy to drive or power micromechanical apparatuses. The invention is adaptable to applications involving defense, bio-medical, manufacturing, consumer product, aviation, automotive, computer, inspection, and safety systems. A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachine techniques (LIGA).

  17. Calibrated vapor generator source

    DOEpatents

    Davies, J.P.; Larson, R.A.; Goodrich, L.D.; Hall, H.J.; Stoddard, B.D.; Davis, S.G.; Kaser, T.G.; Conrad, F.J.

    1995-09-26

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet. 10 figs.

  18. Calibrated vapor generator source

    DOEpatents

    Davies, John P.; Larson, Ronald A.; Goodrich, Lorenzo D.; Hall, Harold J.; Stoddard, Billy D.; Davis, Sean G.; Kaser, Timothy G.; Conrad, Frank J.

    1995-01-01

    A portable vapor generator is disclosed that can provide a controlled source of chemical vapors, such as, narcotic or explosive vapors. This source can be used to test and calibrate various types of vapor detection systems by providing a known amount of vapors to the system. The vapor generator is calibrated using a reference ion mobility spectrometer. A method of providing this vapor is described, as follows: explosive or narcotic is deposited on quartz wool, placed in a chamber that can be heated or cooled (depending on the vapor pressure of the material) to control the concentration of vapors in the reservoir. A controlled flow of air is pulsed over the quartz wool releasing a preset quantity of vapors at the outlet.

  19. Cryogenic monochromator as a solution to undulator heat loads at third generation synchrotron sources

    SciTech Connect

    Knapp, G.S.; Rogers, C.S.; Beno, M.A.; Jennings, G.; Cowan, P.L.

    1994-10-01

    We have developed a new design for a cryogenically cooled monochromator employing a thin-crystal strategy which is capable of handling the central-cone power of the Advanced Photon Source`s Undulator A at closed gap and at the full design current of 300 mA. We have designed and fabricated a Si (111) crystal which has a thin section where the x-rays hit and has internal cooling channels. A invar manifold has also been designed and it will be attached to the Si via In gaskets. We have done detailed modeling, both with approximate analytical and with finite element calculations. The results shown that our design has negligible thermal strain even for closed gap operation.

  20. Heat management in aluminum/air batteries: Sources of heat

    NASA Astrophysics Data System (ADS)

    Patnaik, R. S. M.; Ganesh, S.; Ashok, G.; Ganesan, M.; Kapali, V.

    1994-07-01

    One of the problems with the aluminum/air battery is the generation of heat, during both idle and discharge periods. The main sources of heat are: (1) corrosion of the aluminum anode during the idle period; (2) inefficient, or less efficient, dissolution of anode during discharge; (3) Joule heat during discharge, and (4) non-uniform mass transfer during both discharge and idle periods. These components of heat act in a cumulative way because they are all interconnected. This paper addresses the basic reasons for the origin of these sources of heat. Suitable and practical remedial measures for the effective removal of such heat in the aluminum/air battery are suggested.

  1. Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source

    NASA Astrophysics Data System (ADS)

    Shibata, T.; Nishida, K.; Mochizuki, S.; Mattei, S.; Lettry, J.; Hatayama, A.; Ueno, A.; Oguri, H.; Ohkoshi, K.; Ikegami, K.; Takagi, A.; Asano, H.; Naito, F.

    2016-02-01

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30-120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna.

  2. Numerical study of plasma generation process and internal antenna heat loadings in J-PARC RF negative ion source.

    PubMed

    Shibata, T; Nishida, K; Mochizuki, S; Mattei, S; Lettry, J; Hatayama, A; Ueno, A; Oguri, H; Ohkoshi, K; Ikegami, K; Takagi, A; Asano, H; Naito, F

    2016-02-01

    A numerical model of plasma transport and electromagnetic field in the J-PARC (Japan Proton Accelerator Research Complex) radio frequency ion source has been developed to understand the relation between antenna coil heat loadings and plasma production/transport processes. From the calculation, the local plasma density increase is observed in the region close to the antenna coil. Electrons are magnetized by the magnetic field line with absolute magnetic flux density 30-120 Gauss which leads to high local ionization rate. The results suggest that modification of magnetic configuration can be made to reduce plasma heat flux onto the antenna. PMID:26932010

  3. Mini-Brayton heat source assembly development

    NASA Technical Reports Server (NTRS)

    Wein, D.; Zimmerman, W. F.

    1978-01-01

    The work accomplished on the Mini-Brayton Heat Source Assembly program is summarized. Required technologies to design, fabricate and assemble components for a high temperature Heat Source Assembly (HSA) which would generate and transfer the thermal energy for a spaceborne Brayton Isotope Power System (BIPS) were developed.

  4. Thulium heat sources for space power application

    SciTech Connect

    Alderman, C.J. )

    1993-01-15

    Reliable electrical power supplies for use in transportation and remote systems will be an important part of space exploration activities on planet surfaces. A potential power source is available through the use of thulium, a rare earth metal. Heat sources can be produced by neutron activation of naturally occurring thulium (Tm-169) targets in the base station nuclear power reactor. The resulting Tm-170 heat sources can be used in thermoelectric generators to power instrumentation and telecommunications systems located at remote sites. Combined with a dynamic Sterling or Brayton cycle conversion system, the heat source can power a lightweight electrical source for rovers or other surface transportation systems.

  5. Heat generating compositions for thermal batteries

    NASA Astrophysics Data System (ADS)

    Sheptunov, V. N.

    1991-03-01

    Thermal batteries are widely used as independent current sources with long storage life and the ability to operate over a wide ambient temperature range. A number of pyrotechnic materials may as rule be used as sources of thermal energy to provide ionic conduction in a molten electrolyte and to maintain the working temperature of the battery during the discharge of the electrochemical elements. The requirements for heat sources in thermal batteries are described and different heat generating compositions are reviewed.

  6. Heat generated by knee prostheses.

    PubMed

    Pritchett, James W

    2006-01-01

    Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy. PMID:16394760

  7. Heat operated cryogenic electrical generator

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Saffren, M. M.; Elleman, D. D. (Inventor)

    1975-01-01

    An electrical generator useful for providing electrical power in deep space, is disclosed. The electrical generator utilizes the unusual hydrodynamic property exhibited by liquid helium as it is converted to and from a superfluid state to cause opposite directions of rotary motion for a rotor cell thereof. The physical motion of the rotor cell was employed to move a magnetic field provided by a charged superconductive coil mounted on the exterior of the cell. An electrical conductor was placed in surrounding proximity to the cell to interact with the moving magnetic field provided by the superconductive coil and thereby generate electrical energy. A heat control arrangement was provided for the purpose of causing the liquid helium to be partially converted to and from a superfluid state by being cooled and heated, respectively.

  8. Update to the safety program for the general-purpose heat source radioisotope thermoelectric generators for the Galileo and Ulysses missions

    NASA Technical Reports Server (NTRS)

    Bennett, Gary L.; Bradshaw, C. T.; Englehart, Richard W.; Bartram, Bart W.; Cull, Theresa A.; Zocher, Roy W.; Eck, Marshall B.; Mukunda, Meera; Brenza, Peter T.; Chan, Chris C.

    1992-01-01

    With the rescheduling of the Galileo and Ulysses launches and the use of new upper stages following the Challenger accident, the aerospace nuclear safety program for the general-purpose heat source radioisotope thermoelectric generators (GPHS-RTGs) was extended to accommodate the new mission scenarios. As in the original safety program, the objectives were to determine the response of the GPHS-RTG to the various postulated accident environments and to determine the risk (if any) associated with these postulated accidents. The extended GPHS-RTG safety program was successfully completed in sufficient time to prepare an updated Final Safety Analysis Report (FSAR) with revisions for the October 1989 launch of the Galileo spacecraft.

  9. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... services include cooking, heating, air conditioning (where installed), domestic refrigeration, mechanical... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources....

  10. Performance characteristic of thermosyphon heat pipe at radiant heat source

    NASA Astrophysics Data System (ADS)

    Hrabovský, Peter; Papučík, Štefan; Kaduchová, Katarína

    2016-06-01

    This article discusses about device, which is called heat pipe. This device is with heat source with radiant heat source. Heat pipe is device with high efficiency of heat transfer. The heat pipe, which is describe in this article is termosyphon heat pipe. The experiment with termosyphon heat pipe get a result. On the base of result, it will be in future to create mathematical model in Ansys. Thermosyphon heat pipe is made of copper and distilled water is working fluid. The significance of this experiment consists in getting of the heat transfer and performance characteristic. On the basis of measured and calculated data can be constructed the plots.

  11. Role of radiogenic heat generation in surface heat flow formation

    NASA Astrophysics Data System (ADS)

    Khutorskoi, M. D.; Polyak, B. G.

    2016-03-01

    Heat generation due to decay of long-lived radioactive isotopes is considered in the Earth's crust of the Archean-Proterozoic and Paleozoic provinces of Eurasia and North America. The heat flow that forms in the mantle is calculated as the difference between the heat flow observed at the boundary of the solid Earth and radiogenic heat flow produced in the crust. The heat regime in regions with anomalously high radiogenic heat generation is discussed. The relationship between various heat flow components in the Precambrian and Phanerozoic provinces has been comparatively analyzed, and the role of erosion of the surfaceheat- generating layer has been estimated.

  12. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  13. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  14. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  15. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  16. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  17. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  18. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  19. 30 CFR 57.4500 - Heat sources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Heat sources. 57.4500 Section 57.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 57.4500 Heat sources. Heat sources capable of producing...

  20. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  1. 30 CFR 56.4500 - Heat sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Heat sources. 56.4500 Section 56.4500 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Installation/construction/maintenance § 56.4500 Heat sources. Heat sources capable of producing...

  2. Multiple source navigation signal generator

    NASA Astrophysics Data System (ADS)

    Bojda, Petr

    2010-09-01

    The paper presents a FPGA based digital VOR/LOC signal generator. It provides the composite signal, which consists of the particular signals of several predefined navigation sources - VOR beacons. Design of the generator is implemented into the two different FPGA DSP platforms.

  3. Heat engine generator control system

    DOEpatents

    Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

    1998-05-12

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

  4. Heat engine generator control system

    DOEpatents

    Rajashekara, Kaushik; Gorti, Bhanuprasad Venkata; McMullen, Steven Robert; Raibert, Robert Joseph

    1998-01-01

    An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

  5. ULF Generation by Modulated Ionospheric Heating

    NASA Astrophysics Data System (ADS)

    Chang, C.; Labenski, J.; Wallace, T.; Papadopoulos, K.

    2013-12-01

    Modulated ionospheric heating experiments designed to generate ULF waves using the HAARP heater have been conducted since 2007. Artificial ULF waves in the Pc1 frequency range were observed from space and by ground induction magnetometers located in the vicinity of the heater as well as at long distances. Two distinct generation mechanisms of artificial ULF waves were identified. The first was electroject modulation under geomagnetically disturbed conditions. The second was pressure modulation in the E and F regions of the ionosphere under quiet conditions. Ground detections of ULF waves near the heater included both Shear Alfven waves and Magnetosonic waves generated by electrojet and/or pressure modulations. Distant ULF detections involved Magnetosonic wave propagation in the Alfvenic duct with pressure modulation as the most likely source. Summary of our observations and theoretical interpretations will be presented at the meeting. We would like to acknowledge the support provided by the staff at the HAARP facility during our ULF experiments.

  6. Carbothermic reduction with parallel heat sources

    DOEpatents

    Troup, Robert L.; Stevenson, David T.

    1984-12-04

    Disclosed are apparatus and method of carbothermic direct reduction for producing an aluminum alloy from a raw material mix including aluminum oxide, silicon oxide, and carbon wherein parallel heat sources are provided by a combustion heat source and by an electrical heat source at essentially the same position in the reactor, e.g., such as at the same horizontal level in the path of a gravity-fed moving bed in a vertical reactor. The present invention includes providing at least 79% of the heat energy required in the process by the electrical heat source.

  7. 4th Generation ECR Ion Sources

    SciTech Connect

    Lyneis, Claude M.; Leitner, D.; Todd, D.S.; Sabbi, G.; Prestemon, S.; Caspi, S.; Ferracin, P.

    2008-12-01

    The concepts and technical challenges related to developing a 4th generation ECR ion source with an RF frequency greater than 40 GHz and magnetic confinement fields greater than twice Becr will be explored in this paper. Based on the semi-empirical frequency scaling of ECR plasma density with the square of operating frequency, there should be significant gains in performance over current 3rd generation ECR ion sources, which operate at RF frequencies between 20 and 30 GHz. While the 3rd generation ECR ion sources use NbTi superconducting solenoid and sextupole coils, the new sources will need to use different superconducting materials such as Nb3Sn to reach the required magnetic confinement, which scales linearly with RF frequency. Additional technical challenges include increased bremsstrahlung production, which may increase faster than the plasma density, bremsstrahlung heating of the cold mass and the availability of high power continuous wave microwave sources at these frequencies. With each generation of ECR ion sources, there are new challenges to be mastered, but the potential for higher performance and reduced cost of the associated accelerator continue to make this a promising avenue for development.

  8. Simplified Heat-Source/Thermionic Converter

    NASA Technical Reports Server (NTRS)

    Shimada, K.

    1983-01-01

    Radiation coupling of heat from heat-source cylinder to converter cylinder through vacuum gap eliminates need for high-temperature electrical insulators between reactor heat pipes and thermionic converters. In addition no radiatior heat pipe is necessary because collectors of thermionic converters from which excess heat must be removed radiate directly to space. New design concept is also applicable to terrestrial and non-nuclear thermionic power supplies.

  9. DUAL HEATED ION SOURCE STRUCTURE HAVING ARC SHIFTING MEANS

    DOEpatents

    Lawrence, E.O.

    1959-04-14

    An ion source is presented for calutrons, particularly an electrode arrangement for the ion generator of a calutron ion source. The ion source arc chamber is heated and an exit opening with thermally conductive plates defines the margins of the opening. These plates are electrically insulated from the body of the ion source and are connected to a suitable source of voltage to serve as electrodes for shaping the ion beam egressing from the arc chamber.

  10. Heat-Pipe-Associated Localized Thermoelectric Power Generation System

    NASA Astrophysics Data System (ADS)

    Kim, Pan-Jo; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Jang, Ju-Chan; Lee, Wook-Hyun; Lee, Ki-Woo

    2014-06-01

    The present study focused on how to improve the maximum power output of a thermoelectric generator (TEG) system and move heat to any suitable space using a TEG associated with a loop thermosyphon (loop-type heat pipe). An experimental study was carried out to investigate the power output, the temperature difference of the thermoelectric module (TEM), and the heat transfer performance associated with the characteristic of the researched heat pipe. Currently, internal combustion engines lose more than 35% of their fuel energy as recyclable heat in the exhaust gas, but it is not easy to recycle waste heat using TEGs because of the limited space in vehicles. There are various advantages to use of TEGs over other power sources, such as the absence of moving parts, a long lifetime, and a compact system configuration. The present study presents a novel TEG concept to transfer heat from the heat source to the sink. This technology can transfer waste heat to any location. This simple and novel design for a TEG can be applied to future hybrid cars. The present TEG system with a heat pipe can transfer heat and generate power of around 1.8 V with T TEM = 58°C. The heat transfer performance of a loop-type heat pipe with various working fluids was investigated, with water at high heat flux (90 W) and 0.05% TiO2 nanofluid at low heat flux (30 W to 70 W) showing the best performance in terms of power generation. The heat pipe can transfer the heat to any location where the TEM is installed.

  11. Heat source reentry vehicle design study

    NASA Technical Reports Server (NTRS)

    Ryan, R. L.

    1971-01-01

    The design details are presented of a flight-type heat source reentry vehicle and heat exchanger compatible with the isotope Brayton power conversion system. The reference reentry vehicle and heat exchanger were modified, orbital and superorbital capability was assessed, and a complete set of detail design layout drawings were provided.

  12. High temperature heat source generation with quasi-continuous wave semiconductor lasers at power levels of 6 W for medical use.

    PubMed

    Fujimoto, Takahiro; Imai, Yusuke; Tei, Kazuyoku; Ito, Shinobu; Kanazawa, Hideko; Yamaguchi, Shigeru

    2014-01-01

    We investigate a technology to create a high temperature heat source on the tip surface of the glass fiber proposed for medical surgery applications. Using 4 to 6 W power level semiconductor lasers at a wavelength of 980 nm, a laser coupled fiber tip was preprocessed to contain a certain amount of titanium oxide powder with a depth of 100 μm from the tip surface so that the irradiated low laser energy could be perfectly absorbed to be transferred to thermal energy. Thus, the laser treatment can be performed without suffering from any optical characteristic of the material. A semiconductor laser was operated quasi-continuous wave mode pulse time duration of 180 ms and >95% of the laser energy was converted to thermal energy in the fiber tip. Based on two-color thermometry, by using a gated optical multichannel analyzer with a 0.25 m spectrometer in visible wavelength region, the temperature of the fiber tip was analyzed. The temperature of the heat source was measured to be in excess 3100 K.

  13. Control system for fluid heated steam generator

    DOEpatents

    Boland, J.F.; Koenig, J.F.

    1984-05-29

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  14. Control system for fluid heated steam generator

    DOEpatents

    Boland, James F.; Koenig, John F.

    1985-01-01

    A control system for controlling the location of the nucleate-boiling region in a fluid heated steam generator comprises means for measuring the temperature gradient (change in temperature per unit length) of the heating fluid along the steam generator; means for determining a control variable in accordance with a predetermined function of temperature gradients and for generating a control signal in response thereto; and means for adjusting the feedwater flow rate in accordance with the control signal.

  15. Compact ion source neutron generator

    SciTech Connect

    Schenkel, Thomas; Persaud, Arun; Kapadia, Rehan; Javey, Ali; Chang-Hasnain, Constance; Rangelow, Ivo; Kwan, Joe

    2015-10-13

    A neutron generator includes a conductive substrate comprising a plurality of conductive nanostructures with free-standing tips and a source of an atomic species to introduce the atomic species in proximity to the free-standing tips. A target placed apart from the substrate is voltage biased relative to the substrate to ionize and accelerate the ionized atomic species toward the target. The target includes an element capable of a nuclear fusion reaction with the ionized atomic species to produce a one or more neutrons as a reaction by-product.

  16. Waste heat generation: A comprehensive review.

    PubMed

    Yeşiller, Nazli; Hanson, James L; Yee, Emma H

    2015-08-01

    A comprehensive review of heat generation in various types of wastes and of the thermal regime of waste containment facilities is provided in this paper. Municipal solid waste (MSW), MSW incineration ash, and mining wastes were included in the analysis. Spatial and temporal variations of waste temperatures, thermal gradients, thermal properties of wastes, average temperature differentials, and heat generation values are provided. Heat generation was influenced by climatic conditions, mean annual earth temperatures, waste temperatures at the time of placement, cover conditions, and inherent heat generation potential of the specific wastes. Time to onset of heat generation varied between months and years, whereas timelines for overall duration of heat generation varied between years and decades. For MSW, measured waste temperatures were as high as 60-90°C and as low as -6°C. MSW incinerator ash temperatures varied between 5 and 87°C. Mining waste temperatures were in the range of -25 to 65°C. In the wastes analyzed, upward heat flow toward the surface was more prominent than downward heat flow toward the subsurface. Thermal gradients generally were higher for MSW and incinerator ash and lower for mining waste. Based on thermal properties, MSW had insulative qualities (low thermal conductivity), while mining wastes typically were relatively conductive (high thermal conductivity) with ash having intermediate qualities. Heat generation values ranged from -8.6 to 83.1MJ/m(3) and from 0.6 to 72.6MJ/m(3) for MSW and mining waste, respectively and was 72.6MJ/m(3) for ash waste. Conductive thermal losses were determined to range from 13 to 1111MJ/m(3)yr. The data and analysis provided in this review paper can be used in the investigation of heat generation and thermal regime of a wide range of wastes and waste containment facilities located in different climatic regions.

  17. Waste heat generation: A comprehensive review.

    PubMed

    Yeşiller, Nazli; Hanson, James L; Yee, Emma H

    2015-08-01

    A comprehensive review of heat generation in various types of wastes and of the thermal regime of waste containment facilities is provided in this paper. Municipal solid waste (MSW), MSW incineration ash, and mining wastes were included in the analysis. Spatial and temporal variations of waste temperatures, thermal gradients, thermal properties of wastes, average temperature differentials, and heat generation values are provided. Heat generation was influenced by climatic conditions, mean annual earth temperatures, waste temperatures at the time of placement, cover conditions, and inherent heat generation potential of the specific wastes. Time to onset of heat generation varied between months and years, whereas timelines for overall duration of heat generation varied between years and decades. For MSW, measured waste temperatures were as high as 60-90°C and as low as -6°C. MSW incinerator ash temperatures varied between 5 and 87°C. Mining waste temperatures were in the range of -25 to 65°C. In the wastes analyzed, upward heat flow toward the surface was more prominent than downward heat flow toward the subsurface. Thermal gradients generally were higher for MSW and incinerator ash and lower for mining waste. Based on thermal properties, MSW had insulative qualities (low thermal conductivity), while mining wastes typically were relatively conductive (high thermal conductivity) with ash having intermediate qualities. Heat generation values ranged from -8.6 to 83.1MJ/m(3) and from 0.6 to 72.6MJ/m(3) for MSW and mining waste, respectively and was 72.6MJ/m(3) for ash waste. Conductive thermal losses were determined to range from 13 to 1111MJ/m(3)yr. The data and analysis provided in this review paper can be used in the investigation of heat generation and thermal regime of a wide range of wastes and waste containment facilities located in different climatic regions. PMID:25962825

  18. Heat-generating nuclear reactor

    SciTech Connect

    Dupuy, G.; Fajeau, M.; Labrousse, M.; Lerouge, B.; Minguet, J.

    1981-01-20

    A reactor vessel filled with coolant fluid is divided by a wall into an upper region and a lower region which contains the reactor core, part of the coolant fluid in the upper region being injected into the lower region. The injection flow rate is regulated as a function of the variations in pressure in the lower region by means of a baffle-plate container which communicates with a leak-tight chamber and with a storage reservoir, a flow of fluid from the chamber to the reservoir being established only at the time of a reduction in the rate of injection into the container. The reactor can be employed for the production of hot water which is passed through a heat exchanger and supplied to a heating installation.

  19. Alternative Radioisotopes for Heat and Power Sources

    NASA Astrophysics Data System (ADS)

    Tinsley, T.; Sarsfield, M.; Rice, T.

    Production of 238Pu requires considerable facilities including a nuclear reactor and reprocessing plants that are very expensive to build and operate. Thus, a more economical alternative is very attractive to the industry. There are many alternative radioisotopes that exist but few that satisfy the criteria of performance, availability and cost to produce. Any alternative to 238Pu must exist in a chemical form that is compatible with the materials required to safely encapsulate the heat source at the high temperatures of operation and potential launch failure scenarios. The chemical form must also have suitable thermal properties to ensure maximum energy conversion efficiencies when integrated into radioisotope thermoelectric generators over the required mission durations. In addition, the radiation dose must be low enough for operators during production and not so prohibitive that excessive shielding mass is required on the space craft. This paper will focus on the preferred European alternative of 241Am, and the issues that will need to be addressed.

  20. MEMS CLOSED CHAMBER HEAT ENGINE AND ELECTRIC GENERATOR

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A. (Inventor)

    2005-01-01

    A heat engine, preferably combined with an electric generator, and advantageously implemented using micro-electromechanical system (MEMS) technologies as an array of one or more individual heat engine/generators. The heat engine is based on a closed chamber containing a motive medium, preferably a gas; means for alternately enabling and disabling transfer of thermal energy from a heat source to the motive medium; and at least one movable side of the chamber that moves in response to thermally-induced expansion and contraction of the motive medium, thereby converting thermal energy to oscillating movement. The electrical generator is combined with the heat engine to utilize movement of the movable side to convert mechanical work to electrical energy, preferably using electrostatic interaction in a generator capacitor. Preferably at least one heat transfer side of the chamber is placed alternately into and out of contact with the heat source by a motion capacitor, thereby alternately enabling and disabling conductive transfer of heat to the motive medium.

  1. Heat Management in Thermoelectric Power Generators.

    PubMed

    Zebarjadi, M

    2016-04-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one.

  2. Heat Management in Thermoelectric Power Generators

    NASA Astrophysics Data System (ADS)

    Zebarjadi, M.

    2016-04-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one.

  3. Heat Management in Thermoelectric Power Generators

    PubMed Central

    Zebarjadi, M.

    2016-01-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one. PMID:27033717

  4. Heat Management in Thermoelectric Power Generators.

    PubMed

    Zebarjadi, M

    2016-01-01

    Thermoelectric power generators are used to convert heat into electricity. Like any other heat engine, the performance of a thermoelectric generator increases as the temperature difference on the sides increases. It is generally assumed that as more heat is forced through the thermoelectric legs, their performance increases. Therefore, insulations are typically used to minimize the heat losses and to confine the heat transport through the thermoelectric legs. In this paper we show that to some extend it is beneficial to purposely open heat loss channels in order to establish a larger temperature gradient and therefore to increase the overall efficiency and achieve larger electric power output. We define a modified Biot number (Bi) as an indicator of requirements for sidewall insulation. We show cooling from sidewalls increases the efficiency for Bi values less than one, and decreases the efficiency for Bi values larger than one. PMID:27033717

  5. Heat generation and transport in the heart

    NASA Astrophysics Data System (ADS)

    van Beek, Johannes H. G. M.

    1996-05-01

    During contraction of the heart, a large part of the energy in energy metabolism is converted to heat. The article presents the results of measurements of mechanical stresses in the myocardium and blood vessels, temperatures and rate of heat generation. Experimental data correlate well with the numerical solutions of the biothermal problem.

  6. New geothermal heat extraction process to deliver clean power generation

    ScienceCinema

    Pete McGrail

    2016-07-12

    A new method for capturing significantly more heat from low-temperature geothermal resources holds promise for generating virtually pollution-free electrical energy. Scientists at the Department of Energys Pacific Northwest National Laboratory will determine if their innovative approach can safely and economically extract and convert heat from vast untapped geothermal resources. The goal is to enable power generation from low-temperature geothermal resources at an economical cost. In addition to being a clean energy source without any greenhouse gas emissions, geothermal is also a steady and dependable source of power.

  7. Space factor of "excess" heat generation in the Earth and planetary interiors. Article 5. Possible heat generating particles

    NASA Astrophysics Data System (ADS)

    Makarenko, O. M.

    Besides radiogenic energy, the "extra" energy source occurs in the Earth interior. This source is of cosmic origin and modulated by position and direction of the Solar system motion in the Galaxy. Dark matter from the galactic disk might be a factor leading to the energy release. Candidate heat generating particles are: particles of the fourth generation, axions, magnetic monopoles, small black holes, and some others.

  8. Heat generation during metamorphic processes in snow

    NASA Astrophysics Data System (ADS)

    Tyagunin, A. V.; Koposov, G. D.

    2016-09-01

    The research analyzes known metamorphic processes in the snow from the point of view of energy approach. A list of these processes is complemented with the processes associated with runoff of a quasi-liquid layer from snow granules. The experimental results of studying the heat generation from the snow cover and the temperature gradient at the depth of the snow cover are presented. It is emphasized that snow cover is not merely a passive conductor of heat but also it is a heat generating medium.

  9. Can HF heating generate ESF bubbles?

    NASA Astrophysics Data System (ADS)

    Zawdie, K. A.; Huba, J. D.

    2014-12-01

    The injection of powerful HF waves into the ionosphere can lead to strong electron heating followed by a pressure perturbation which can locally reduce the plasma density. In the postsunset equatorial ionosphere, density perturbations can provide the seed to generate equatorial spread F (ESF) bubbles. In this paper, a modified version of the SAMI3/ESF ionosphere code is used to model the density depletions created by HF heating and to determine if ESF bubbles can be artificially generated. It is found that HF heating primarily redistributes plasma along the geomagnetic field and does not significantly perturb the flux tube integrated conductivities. Thus, HF heating does not appear to be a viable method to seed or generate ESF bubbles.

  10. Hoosac tunnel geothermal heat source. Final report

    SciTech Connect

    Not Available

    1982-06-10

    The Hoosac Rail Tunnel has been analyzed as a central element in a district heating system for the City of North Adams. The tunnel has been viewed as a collector of the earth's geothermal heat and a seasonal heat storage facility with heat piped to the tunnel in summer from existing facilities at a distance. Heated fluid would be transported in winter from the tunnel to users who would boost the temperature with individual heat pumps. It was concluded the tunnel is a poor source of geothermal heat. The maximum extractable energy is only 2200 million BTU (20000 gallons of oil) at 58/sup 0/F. The tunnel is a poor heat storage facility. The rock conductivity is so high that 75% of the heat injected would escape into the mountain before it could be recaptured for use. A low temperature system, with individual heat pumps for temperature boost could be economically attractive if a low cost fuel (byproduct, solid waste, cogeneration) or a cost effective seasonal heat storage were available.

  11. Generator powered electrically heated diesel particulate filter

    DOEpatents

    Gonze, Eugene V; Paratore, Jr., Michael J

    2014-03-18

    A control circuit for a vehicle powertrain includes a switch that selectivity interrupts current flow between a first terminal and a second terminal. A first power source provides power to the first terminal and a second power source provides power to the second terminal and to a heater of a heated diesel particulate filter (DPF). The switch is opened during a DPF regeneration cycle to prevent the first power source from being loaded by the heater while the heater is energized.

  12. Characterization and modeling of the heat source

    SciTech Connect

    Glickstein, S.S.; Friedman, E.

    1993-10-01

    A description of the input energy source is basic to any numerical modeling formulation designed to predict the outcome of the welding process. The source is fundamental and unique to each joining process. The resultant output of any numerical model will be affected by the initial description of both the magnitude and distribution of the input energy of the heat source. Thus, calculated weld shape, residual stresses, weld distortion, cooling rates, metallurgical structure, material changes due to excessive temperatures and potential weld defects are all influenced by the initial characterization of the heat source. Understandings of both the physics and the mathematical formulation of these sources are essential for describing the input energy distribution. This section provides a brief review of the physical phenomena that influence the input energy distributions and discusses several different models of heat sources that have been used in simulating arc welding, high energy density welding and resistance welding processes. Both simplified and detailed models of the heat source are discussed.

  13. Heat flow and heat generation in greenstone belts

    NASA Technical Reports Server (NTRS)

    Drury, M. J.

    1986-01-01

    Heat flow has been measured in Precambrian shields in both greenstone belts and crystalline terrains. Values are generally low, reflecting the great age and tectonic stability of the shields; they range typically between 30 and 50 mW/sq m, although extreme values of 18 and 79 mW/sq m have been reported. For large areas of the Earth's surface that are assumed to have been subjected to a common thermotectonic event, plots of heat flow against heat generation appear to be linear, although there may be considerable scatter in the data. The relationship is expressed as: Q = Q sub o + D A sub o in which Q is the observed heat flow, A sub o is the measured heat generation at the surface, Q sub o is the reduced heat flow from the lower crust and mantle, and D, which has the dimension of length, represents a scale depth for the distribution of radiogenic elements. Most authors have not used data from greenstone belts in attempting to define the relationship within shields, considering them unrepresentative and preferring to use data from relatively homogeneous crystalline rocks. A discussion follows.

  14. Life cycle assessment of base-load heat sources for district heating system options

    SciTech Connect

    Ghafghazi, Saeed; Sowlati, T.; Sokhansanj, Shahabaddine; Melin, Staffan

    2011-03-01

    Purpose There has been an increased interest in utilizing renewable energy sources in district heating systems. District heating systems are centralized systems that provide heat for residential and commercial buildings in a community. While various renewable and conventional energy sources can be used in such systems, many stakeholders are interested in choosing the feasible option with the least environmental impacts. This paper evaluates and compares environmental burdens of alternative energy source options for the base load of a district heating center in Vancouver, British Columbia (BC) using the life cycle assessment method. The considered energy sources include natural gas, wood pellet, sewer heat, and ground heat. Methods The life cycle stages considered in the LCA model cover all stages from fuel production, fuel transmission/transportation, construction, operation, and finally demolition of the district heating system. The impact categories were analyzed based on the IMPACT 2002+ method. Results and discussion On a life-cycle basis, the global warming effect of renewable energy options were at least 200 kgeqCO2 less than that of the natural gas option per MWh of heat produced by the base load system. It was concluded that less than 25% of the upstream global warming impact associated with the wood pellet energy source option was due to transportation activities and about 50% of that was resulted from wood pellet production processes. In comparison with other energy options, the wood pellets option has higher impacts on respiratory of inorganics, terrestrial ecotoxicity, acidification, and nutrification categories. Among renewable options, the global warming impact of heat pump options in the studied case in Vancouver, BC, were lower than the wood pellet option due to BC's low carbon electricity generation profile. Ozone layer depletion and mineral extraction were the highest for the heat pump options due to extensive construction required for these

  15. Thermoplastic analysis of general-purpose heat-source modules

    NASA Astrophysics Data System (ADS)

    Chang, Y.; Ecker, J. A.

    1993-01-01

    Prior thermoelastic analyses were conducted to assess the thermostructural response of the Galileo radioisotope thermoelectric generators general-purpose heat-source (GPHS) modules upon possible accidental reentry into earth's atmosphere. These analyses are extended through the inclusion of thermoplasticity of the composite material of the GPHS modules. The thermoplastic analysis methods for GPHS composite material are presented.

  16. Thermoelectric Generators used as Cryogenic Heat Engines

    NASA Astrophysics Data System (ADS)

    Smith, D. E.; Ordonez, C. A.

    1997-03-01

    A future experiment is being planned at the University of North Texas to design, build, and test a cryogenic heat engine(C. A. Ordonez, Am. J. Phys. 64), 479 (1996). suitable as an electric-vehicle power system. The power system shall then be installed in a demonstration vehicle. This will be a next-generation vehicle following the current project described in the accompanying poster, ``Experimental Car Which Uses Liquid Nitrogen as Its Fuel" by M. E. Parker et al. The cryogenic heat engine electric vehicle power system will incorporate both a thermoelectric generator and an ambient-temperature turbine or pneumatic-motor/generator. The thermoelectric generator shall use liquid nitrogen (under pressure) as its cold reservoir. Energy is produced with the thermoelectric generator by using the liquid/gas phase change to absorb heat. At the present time a study is being carried out to determine the efficiency of thermoelectric devices which are used as cryogenic heat engines. Initial data is being taken using frozen H_2O and CO2 as cold reservoirs. The results of the study shall be presented.

  17. Heat Deposition in Positron Sources for ILC

    SciTech Connect

    Bharadwaj, V.; Pitthan, R.; Sheppard, J.; Vincke, H.; Wang, J.W.; /SLAC

    2006-03-15

    In the International Linear Collider (ILC) positron source, multi-GeV electrons or multi-MeV photons impinge on a metal target to produce the needed positrons in the resulting electromagnetic showers. The incoming beam power is hundreds of kilowatts. Various computer programs -- such as FLUKA or MARS -- can calculate how the incoming beam showers in the target and can track the particle showers through the positron source system. Most of the incoming energy ends up as heat in the various positron source elements. This paper presents results from such calculations and their impact on the design of a positron source for the ILC.

  18. TEM Pump With External Heat Source And Sink

    NASA Technical Reports Server (NTRS)

    Nesmith, Bill J.

    1991-01-01

    Proposed thermoelectric/electromagnetic (TEM) pump driven by external source of heat and by two or more heat pipe radiator heat sink(s). Thermoelectrics generate electrical current to circulate liquid metal in secondary loop of two-fluid-loop system. Intended for use with space and terrestrial dual loop liquid metal nuclear reactors. Applications include spacecraft on long missions or terrestrial beacons or scientific instruments having to operate in remote areas for long times. Design modified to include multiple radiators, converters, and ducts, as dictated by particular application.

  19. Solar steam generation by heat localization.

    PubMed

    Ghasemi, Hadi; Ni, George; Marconnet, Amy Marie; Loomis, James; Yerci, Selcuk; Miljkovic, Nenad; Chen, Gang

    2014-07-21

    Currently, steam generation using solar energy is based on heating bulk liquid to high temperatures. This approach requires either costly high optical concentrations leading to heat loss by the hot bulk liquid and heated surfaces or vacuum. New solar receiver concepts such as porous volumetric receivers or nanofluids have been proposed to decrease these losses. Here we report development of an approach and corresponding material structure for solar steam generation while maintaining low optical concentration and keeping the bulk liquid at low temperature with no vacuum. We achieve solar thermal efficiency up to 85% at only 10 kW m(-2). This high performance results from four structure characteristics: absorbing in the solar spectrum, thermally insulating, hydrophilic and interconnected pores. The structure concentrates thermal energy and fluid flow where needed for phase change and minimizes dissipated energy. This new structure provides a novel approach to harvesting solar energy for a broad range of phase-change applications.

  20. Light bulb heat exchanger for magnetohydrodynamic generator applications - Preliminary evaluation

    NASA Technical Reports Server (NTRS)

    Smith, J. M.; Hwang, C. C.; Seikel, G. R.

    1974-01-01

    The light-bulb heat-exchanger concept is investigated as a possible means of using a combustion heat source to supply energy to an inert gas MHD power generator system. In this concept, combustion gases flow through a central passage which consists of a duct with transparent walls through which heat is transferred by radiation to a radiation receiver which in turn heats the inert gas by convection. The effects of combustion-gas emissivity, transparent-wall-transmissivity, radiation-receiver emissivity, and the use of fins in the inert gas coolant passage are studied. The results indicate that inert gas outlet temperatures of 2500 K are possible for combustion temperatures of 3200 K and that sufficient energy can be transferred from the combustion gas to reduce its temperature to approximately 2000 K. At this temperature more conventional heat exchangers can be used.

  1. Heat Pipe-Assisted Thermoelectric Power Generation Technology for Waste Heat Recovery

    NASA Astrophysics Data System (ADS)

    Jang, Ju-Chan; Chi, Ri-Guang; Rhi, Seok-Ho; Lee, Kye-Bock; Hwang, Hyun-Chang; Lee, Ji-Su; Lee, Wook-Hyun

    2015-06-01

    Currently, large amounts of thermal energy dissipated from automobiles are emitted through hot exhaust pipes. This has resulted in the need for a new efficient recycling method to recover energy from waste hot exhaust gas. The present experimental study investigated how to improve the power output of a thermoelectric generator (TEG) system assisted by a wickless loop heat pipe (loop thermosyphon) under the limited space of the exhaust gas pipeline. The present study shows a novel loop-type heat pipe-assisted TEG concept to be applied to hybrid vehicles. The operating temperature of a TEG's hot side surface should be as high as possible to maximize the Seebeck effect. The present study shows a novel TEG concept of transferring heat from the source to the sink. This technology can transfer waste heat to any local place with a loop-type heat pipe. The present TEG system with a heat pipe can transfer heat and generate an electromotive force power of around 1.3 V in the case of 170°C hot exhaust gas. Two thermoelectric modules (TEMs) for a conductive block model and four Bi2Te3 TEMs with a heat pipe-assisted model were installed in the condenser section. Heat flows to the condenser section from the evaporator section connected to the exhaust pipe. This novel TEG system with a heat pipe can be placed in any location on an automobile.

  2. Reprint of : Thermoelectricity without absorbing energy from the heat sources

    NASA Astrophysics Data System (ADS)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-08-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

  3. Thermoelectricity without absorbing energy from the heat sources

    NASA Astrophysics Data System (ADS)

    Whitney, Robert S.; Sánchez, Rafael; Haupt, Federica; Splettstoesser, Janine

    2016-01-01

    We analyze the power output of a quantum dot machine coupled to two electronic reservoirs via thermoelectric contacts, and to two thermal reservoirs - one hot and one cold. This machine is a nanoscale analogue of a conventional thermocouple heat-engine, in which the active region being heated is unavoidably also exchanging heat with its cold environment. Heat exchange between the dot and the thermal reservoirs is treated as a capacitive coupling to electronic fluctuations in localized levels, modeled as two additional quantum dots. The resulting multiple-dot setup is described using a master equation approach. We observe an "exotic" power generation, which remains finite even when the heat absorbed from the thermal reservoirs is zero (in other words the heat coming from the hot reservoir all escapes into the cold environment). This effect can be understood in terms of a non-local effect in which the heat flow from heat source to the cold environment generates power via a mechanism which we refer to as Coulomb heat drag. It relies on the fact that there is no relaxation in the quantum dot system, so electrons within it have a non-thermal energy distribution. More poetically, one can say that we find a spatial separation of the first-law of thermodynamics (heat to work conversion) from the second-law of thermodynamics (generation of entropy). We present circumstances in which this non-thermal system can generate more power than any conventional macroscopic thermocouple (with local thermalization), even when the latter works with Carnot efficiency.

  4. Distributed Generation with Heat Recovery and Storage

    SciTech Connect

    Siddiqui, Afzal; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2005-07-29

    Electricity generated by distributed energy resources (DER) located close to end-use loads has the potential to meet consumer requirements more efficiently than the existing centralized grid. Installation of DER allows consumers to circumvent the costs associated with transmission congestion and other non-energy costs of electricity delivery and potentially to take advantage of market opportunities to purchase energy when attractive. On-site thermal power generation is typically less efficient than central station generation, but by avoiding non-fuel costs of grid power and utilizing combined heat and power (CHP) applications, i.e., recovering heat from small-scale on-site generation to displace fuel purchases, then DER can become attractive to a strictly cost-minimizing consumer. In previous efforts, the decisions facing typical commercial consumers have been addressed using a mixed-integer linear programme, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, and information (both technical and financial) on candidate DER technologies, DER-CAM minimizes the overall energy cost for a test year by selecting the units to install and determining their hourly operating schedules. In this paper, the capabilities of DER-CAM are enhanced by the inclusion of the option to store recovered low-grade heat. By being able to keep an inventory of heat for use in subsequent periods, sites are able to lower costs even further by reducing off-peak generation and relying on storage. This and other effects of storages are demonstrated by analysis of five typical commercial buildings in San Francisco, California, and an estimate of the cost per unit capacity of heat storage is calculated.

  5. Ceramic fuel pellets for isotopic heat sources

    SciTech Connect

    Rankin, D.T.; Congdon, J.W.; Livingston, J.T.; Duncan, N.D.

    1980-01-01

    The General-Purpose Heat Source (GPHS) will supply power for future space missions. The GPHS fuel pellets are fabricated by hot pressing a blended mixture of /sup 238/PuO/sub 2/ granules prepared from calcined plutonium oxalate. Results of a test program which led to the development of the production process are described.

  6. Prandtl Number Dependent Natural Convection with Internal Heat Sources

    SciTech Connect

    Kang Hee Lee; Seung Dong Lee; Kune Y. Suh; Joy L. Rempe; Fan-Bill Cheung; Sang B. Kim

    2004-06-01

    Natural convection plays an important role in determining the thermal load from debris accumulated in the reactor vessel lower head during a severe accident. Recently, attention is being paid to the feasibility of external vessel flooding as a severe accident management strategy and to the phenomena affecting the success path for retaining the molten core material inside the vessel. The heat transfer inside the molten core material can be characterized by the strong buoyancy-induced flows resulting from internal heating due to decay of fission products. The thermo-fluid dynamic characteristics of such flow depend strongly on the thermal boundary conditions. The spatial and temporal variation of heat flux on the pool wall boundaries and the pool superheat are mainly characterized by the natural convection flow inside the molten pool. In general, the natural convection heat transfer phenomena involving the internal heat generation are represented by the modified Rayleigh number (Ra’), which quantifies the internal heat source and hence the strength of the buoyancy force. In this study, tests were conducted in a rectangular section 250 mm high, 500 mm long and 160 mm wide. Twenty-four T-type thermocouples were installed in the test section to measure temperatures. Four T-type thermocouples were used to measure the boundary temperatures. The thermocouples were placed in designated locations after calibration. A direct heating method was adopted in this test to simulate the uniform heat generation. The experiments covered a range of Ra' between 1.5x106 and 7.42x1015 and the Prandtl number (Pr) between 0.7 and 6.5. Tests were conducted with water and air as simulant. The upper and lower boundary conditions were maintained uniform. The results demonstrated feasibility of the direct heating method to simulate uniform volumetric heat generation. Particular attentions were paid to the effect of Pr on natural convection heat transfer within the rectangular pool.

  7. BWR Source Term Generation and Evaluation

    SciTech Connect

    J.C. Ryman

    2003-07-31

    This calculation is a revision of a previous calculation (Ref. 7.5) that bears the same title and has the document identifier BBAC00000-01717-0210-00006 REV 01. The purpose of this revision is to remove TBV (to-be-verified) -41 10 associated with the output files of the previous version (Ref. 7.30). The purpose of this and the previous calculation is to generate source terms for a representative boiling water reactor (BWR) spent nuclear fuel (SNF) assembly for the first one million years after the SNF is discharged from the reactors. This calculation includes an examination of several ways to represent BWR assemblies and operating conditions in SAS2H in order to quantify the effects these representations may have on source terms. These source terms provide information characterizing the neutron and gamma spectra in particles per second, the decay heat in watts, and radionuclide inventories in curies. Source terms are generated for a range of burnups and enrichments (see Table 2) that are representative of the waste stream and stainless steel (SS) clad assemblies. During this revision, it was determined that the burnups used for the computer runs of the previous revision were actually about 1.7% less than the stated, or nominal, burnups. See Section 6.6 for a discussion of how to account for this effect before using any source terms from this calculation. The source term due to the activation of corrosion products deposited on the surfaces of the assembly from the coolant is also calculated. The results of this calculation support many areas of the Monitored Geologic Repository (MGR), which include thermal evaluation, radiation dose determination, radiological safety analyses, surface and subsurface facility designs, and total system performance assessment. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Disposal Container (Ref. 7.27, page 7). Therefore, this calculation is subject to the requirements of the

  8. Circulatory heat sources for canine respiratory heat exchange.

    PubMed Central

    Solway, J; Leff, A R; Dreshaj, I; Munoz, N M; Ingenito, E P; Michaels, D; Ingram, R H; Drazen, J M

    1986-01-01

    We assessed the roles of the pulmonary and bronchial circulations as potential heat sources to the pulmonary airways during respiratory heat loss, by observing the changes in airstream temperature that accompanied temporary occlusion of the pulmonary or bronchial circulations. Baseline end-expiratory and end-inspiratory airstream temperatures were 35.4 +/- 0.2 degrees C (SEM) and 30.9 +/- 0.3 degrees C, respectively, among all trials. With occlusion of the lower lobe pulmonary arteries for 3 min ipsilateral end-expiratory and end-inspiratory airstream temperatures fell by 2.8 +/- 0.2 and 1.1 +/- 0.2 degrees C, respectively, during hyperpnea with room temperature air, and by 3.5 +/- 0.5 and 1.8 +/- 0.2 degrees C, respectively, during hyperpnea with frigid air. In marked contrast, interruption of the bronchial circulation for 3 min had no effect on airstream temperatures. These data indicate that under these conditions, the pulmonary circulation, but not the bronchial circulation, serves as an important local heat source for respiratory heat exchange within the pulmonary airways. Images PMID:3760181

  9. Assessment of dynamic energy conversion systems for radioisotope heat sources

    SciTech Connect

    Thayer, G.R.; Mangeng, C.A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were Stirling; Brayton Cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos Multiattribute Decision Theory code. Three different heat source designs were used: case I with a beginning of life (BOL) source temperature of 640 C, case II with a BOL source temperature of 745/sup 0/C, and case III with a BOL source temperature of 945/sup 0/C. The Stirling engine system was the top-ranked system of cases I and II, closely followed by the ORC systems in case I and ORC plus thermoelectrics in case II. The Brayton cycle system was top-ranked for case III, with the Stirling engine system a close second. The use of /sup 238/Pu in heat source sizes of 7500 W(t) was examined and found to be questionable because of cost and material availability and because of additional requirements for analysis of safeguards and critical mass.

  10. Assessment of dynamic energy conversion systems for radioisotope heat sources

    NASA Astrophysics Data System (ADS)

    Thayer, G. R.; Mangeng, C. A.

    1985-06-01

    The use of dynamic conversion systems to convert the heat generated in a 7500 W(t) 90 Sr radioisotopic heat source to electricity is examined. The systems studies were: Stirling; Brayton cycle; three organic Rankines (ORCs) (Barber-Nichols/ORMAT, Sundstrand, and TRW); and an organic Rankine plus thermoelectrics. The systems were ranked for a North Warning System mission using a Los Alamos multiattribute decision theory code. Three different heat source designs were used: case 1 with a beginning of life (BOL) source temperature of 640 C, case 2 with a BOL source temperature of 745 C, and case 3 with a BOL source temperature of 945 C. The Stirling engine system was the top-ranked system of case 1 and 2, closely followed by the ORC systems in case 1 and ORC plus thermoelectrics in case 2. The Brayton cycle system was top-ranked for case 3, with the Stirling engine system a close second. The use of (238) Pu in heat source sizes of 7500 W(t) is examined and it is found to be questionable because of cost and material availability and because of additional requirements for anlaysis of safeguards and critical mass.

  11. Thermoelectric power generator for variable thermal power source

    DOEpatents

    Bell, Lon E; Crane, Douglas Todd

    2015-04-14

    Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

  12. Distributed Generation with Heat Recovery and Storage

    SciTech Connect

    Siddiqui, Afzal S.; Marnay, Chris; Firestone, Ryan M.; Zhou, Nan

    2006-06-16

    Electricity produced by distributed energy resources (DER)located close to end-use loads has the potential to meet consumerrequirements more efficiently than the existing centralized grid.Installation of DER allows consumers to circumvent the costs associatedwith transmission congestion and other non-energy costs of electricitydelivery and potentially to take advantage of market opportunities topurchase energy when attractive. On-site, single-cycle thermal powergeneration is typically less efficient than central station generation,but by avoiding non-fuel costs of grid power and by utilizing combinedheat and power (CHP) applications, i.e., recovering heat from small-scaleon-site thermal generation to displace fuel purchases, DER can becomeattractive to a strictly cost-minimizing consumer. In previous efforts,the decisions facing typical commercial consumers have been addressedusing a mixed-integer linear program, the DER Customer Adoption Model(DER-CAM). Given the site s energy loads, utility tariff structure, andinformation (both technical and financial) on candidate DER technologies,DER-CAM minimizes the overall energy cost for a test year by selectingthe units to install and determining their hourly operating schedules. Inthis paper, the capabilities of DER-CAM are enhanced by the inclusion ofthe option to store recovered low-grade heat. By being able to keep aninventory of heat for use in subsequent periods, sites are able to lowercosts even further by reducing lucrative peak-shaving generation whilerelying on storage to meet heat loads. This and other effects of storageare demonstrated by analysis of five typical commercial buildings in SanFrancisco, California, USA, and an estimate of the cost per unit capacityof heat storage is calculated.

  13. 60-watt isotopic heat source for terrestrial applications

    NASA Astrophysics Data System (ADS)

    Brittain, Wayne M.

    1995-01-01

    A sealed isotopic heat source (IHS) with a nominal thermal inventory of 60 watts is being developed by the U.S. Department of Energy (DOE) for use in remote terrestrial applications that require isotopic power for electrical power generation. Emphasis is on use in radioisotope thermoelectric generators (RTGs) and dynamic cycle power units. The selected IHS design incorporates technologies developed for prior space and terrestrial IHSs to minimize development cost and span time. A General Purpose Heat Source (GPHS) Fueled Clad (FC), comprised of a plutonium-238 enriched pressed-plutonia pellet contained within a vented iridium clad, is the source for thermal energy. The GPHS FC technology was developed by DOE for use in space RTGs. The GPHS FC is, in turn, enclosed within a three-layer cladding system similar to that developed by DOE for earlier terrestrial heat sources. The cladding system provides for retention of the helium gas generated by the decay of the isotopic fuel and containment of the isotopic fuel under normal operating and accident conditions. Test hardware is currently being fabricated and safety demonstration testing is scheduled to be completed in early 1995.

  14. Electricity generation by intermittent sources

    NASA Astrophysics Data System (ADS)

    Wagner, F.

    2015-08-01

    This paper deals with the production of electricity by wind and photovoltaic (PV) power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES) instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  15. Laser induced heat source distribution in bio-tissues

    NASA Astrophysics Data System (ADS)

    Li, Xiaoxia; Fan, Shifu; Zhao, Youquan

    2006-09-01

    During numerical simulation of laser and tissue thermal interaction, the light fluence rate distribution should be formularized and constituted to the source term in the heat transfer equation. Usually the solution of light irradiative transport equation is given in extreme conditions such as full absorption (Lambert-Beer Law), full scattering (Lubelka-Munk theory), most scattering (Diffusion Approximation) et al. But in specific conditions, these solutions will induce different errors. The usually used Monte Carlo simulation (MCS) is more universal and exact but has difficulty to deal with dynamic parameter and fast simulation. Its area partition pattern has limits when applying FEM (finite element method) to solve the bio-heat transfer partial differential coefficient equation. Laser heat source plots of above methods showed much difference with MCS. In order to solve this problem, through analyzing different optical actions such as reflection, scattering and absorption on the laser induced heat generation in bio-tissue, a new attempt was made out which combined the modified beam broaden model and the diffusion approximation model. First the scattering coefficient was replaced by reduced scattering coefficient in the beam broaden model, which is more reasonable when scattering was treated as anisotropic scattering. Secondly the attenuation coefficient was replaced by effective attenuation coefficient in scattering dominating turbid bio-tissue. The computation results of the modified method were compared with Monte Carlo simulation and showed the model provided reasonable predictions of heat source term distribution than past methods. Such a research is useful for explaining the physical characteristics of heat source in the heat transfer equation, establishing effective photo-thermal model, and providing theory contrast for related laser medicine experiments.

  16. HTGR nuclear heat source component design and experience

    SciTech Connect

    Peinado, C.O.; Wunderlich, R.G.; Simon, W.A.

    1982-05-01

    The high-temperature gas-cooled reactor (HTGR) nuclear heat source components have been under design and development since the mid-1950's. Two power plants have been designed, constructed, and operated: the Peach Bottom Atomic Power Station and the Fort St. Vrain Nuclear Generating Station. Recently, development has focused on the primary system components for a 2240-MW(t) steam cycle HTGR capable of generating about 900 MW(e) electric power or alternately producing high-grade steam and cogenerating electric power. These components include the steam generators, core auxiliary heat exchangers, primary and auxiliary circulators, reactor internals, and thermal barrier system. A discussion of the design and operating experience of these components is included.

  17. Ion Heating in Pulsed Helicon Sources

    NASA Astrophysics Data System (ADS)

    Scime, Earl; Magee, Richard; Carr, Jerry, Jr.; Galante, Matthew; Lusk, Greg; McCarren, Dustin; Reynolds, Eric; Sears, Stephanie; Vandervort, Robert; Hardin, Robert

    2011-10-01

    Previous measurements demonstrated a strong correlation between ion temperature and the ratio of the antenna frequency to the local lower hybrid frequency. When strong ion heating occurs, the ion temperature profile in steady-state helicon sources is flat or peaked at the edge; suggesting an edge localized ion heating mechanism. The same parameters that yield the largest ion temperatures are also predicted to have the strongest damping of slow waves in the edge. Here we present observations that further support the conclusion that short wavelength slow waves parametrically decay into electrostatic modes and also directly heat ions. Collective Thomson scattering measurements indicate significant wave power at frequencies of f ~ 100 kHz and perpendicular wave numbers of ~ 89 rad/cm. The waves are localized to the same region as lower frequency ion acoustic waves are observed with probes. By pulsing the helicon source and observing the time evolution of the ion temperature profile, we find that the ion temperature profile flattens out and then becomes hollow at the same time the parametrically driven ion acoustic waves appear.

  18. Modeling a Thermoelectric Generator Applied to Diesel Automotive Heat Recovery

    NASA Astrophysics Data System (ADS)

    Espinosa, N.; Lazard, M.; Aixala, L.; Scherrer, H.

    2010-09-01

    Thermoelectric generators (TEGs) are outstanding devices for automotive waste heat recovery. Their packaging, lack of moving parts, and direct heat to electrical conversion are the main benefits. Usually, TEGs are modeled with a constant hot-source temperature. However, energy in exhaust gases is limited, thus leading to a temperature decrease as heat is recovered. Therefore thermoelectric properties change along the TEG, affecting performance. A thermoelectric generator composed of Mg2Si/Zn4Sb3 for high temperatures followed by Bi2Te3 for low temperatures has been modeled using engineering equation solver (EES) software. The model uses the finite-difference method with a strip-fins convective heat transfer coefficient. It has been validated on a commercial module with well-known properties. The thermoelectric connection and the number of thermoelements have been addressed as well as the optimum proportion of high-temperature material for a given thermoelectric heat exchanger. TEG output power has been estimated for a typical commercial vehicle at 90°C coolant temperature.

  19. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  20. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  1. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  2. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  3. 21 CFR 872.6475 - Heat source for bleaching teeth.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Heat source for bleaching teeth. 872.6475 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Miscellaneous Devices § 872.6475 Heat source for bleaching teeth. (a) Identification. A heat source for bleaching teeth is an AC-powered device that consists of...

  4. Source-Independent Quantum Random Number Generation

    NASA Astrophysics Data System (ADS)

    Cao, Zhu; Zhou, Hongyi; Yuan, Xiao; Ma, Xiongfeng

    2016-01-01

    Quantum random number generators can provide genuine randomness by appealing to the fundamental principles of quantum mechanics. In general, a physical generator contains two parts—a randomness source and its readout. The source is essential to the quality of the resulting random numbers; hence, it needs to be carefully calibrated and modeled to achieve information-theoretical provable randomness. However, in practice, the source is a complicated physical system, such as a light source or an atomic ensemble, and any deviations in the real-life implementation from the theoretical model may affect the randomness of the output. To close this gap, we propose a source-independent scheme for quantum random number generation in which output randomness can be certified, even when the source is uncharacterized and untrusted. In our randomness analysis, we make no assumptions about the dimension of the source. For instance, multiphoton emissions are allowed in optical implementations. Our analysis takes into account the finite-key effect with the composable security definition. In the limit of large data size, the length of the input random seed is exponentially small compared to that of the output random bit. In addition, by modifying a quantum key distribution system, we experimentally demonstrate our scheme and achieve a randomness generation rate of over 5 ×103 bit /s .

  5. Optimal Ground Source Heat Pump System Design

    SciTech Connect

    Ozbek, Metin; Yavuzturk, Cy; Pinder, George

    2015-04-15

    Despite the facts that GSHPs first gained popularity as early as the 1940’s and they can achieve 30 to 60 percent in energy savings and carbon emission reductions relative to conventional HVAC systems, the use of geothermal energy in the U.S. has been less than 1 percent of the total energy consumption. The key barriers preventing this technically-mature technology from reaching its full commercial potential have been its high installation cost and limited consumer knowledge and trust in GSHP systems to deliver the technology in a cost-effective manner in the market place. Led by ENVIRON, with support from University Hartford and University of Vermont, the team developed and tested a software-based a decision making tool (‘OptGSHP’) for the least-cost design of ground-source heat pump (‘GSHP’) systems. OptGSHP combines state of the art optimization algorithms with GSHP-specific HVAC and groundwater flow and heat transport simulation. The particular strength of OptGSHP is in integrating heat transport due to groundwater flow into the design, which most of the GSHP designs do not get credit for and therefore are overdesigned.

  6. Experimental investigation on thermoelectric generator of micro hybrid power source

    NASA Astrophysics Data System (ADS)

    Shang, Yonghong; Li, Yanqiu; Yu, Hongyun; Sun, Hongguang; Su, Bo

    2007-12-01

    The micro power system, which is composed of photovoltaic solar cell, heat conductor, thermoelectric generator (TEG) module and fin heat sink has been developed in our laboratory. A photovoltaic silicon solar cell of the P-N junction type is sensitive to radiant energy of wavelength from 5,000 Å to 12,000 Å. Radiation under and within this range is converted not only into electric energy but also into heat energy. The wavelength longer than this range is also converted into heat energy, which degrades the conversion efficiency of the solar cell. TEG produces electrical power from temperature difference via Seebeck effect that can be put under the solar cell to absorb the heat. The heat energy can be converted into electrical power. It was found that when TEG surface area was 150mm×60mm, it could generate 0.24V output voltage and 4.18mA short circuit at ambient temperature varying between 5-10°C at winter. It also could generate 1.3V output voltage and 16mA short circuit at ambient temperature varying between 30-36°C at summer. In fact we can use a dc-dc boost up converter to enlarge the output voltage to meet the requirements of wireless sensor network nodes or its recharging battery. It will be an alternative power source for many portable electronic types of equipment.

  7. Development of an Air-Source Heat Pump Integrated with a Water Heating / Dehumidification Module

    SciTech Connect

    Rice, C Keith; Uselton, Robert B.; Shen, Bo; Baxter, Van D; Shrestha, Som S

    2014-01-01

    A residential-sized dual air-source integrated heat pump (AS-IHP) concept is under development in partnership between ORNL and a manufacturer. The concept design consists of a two-stage air-source heat pump (ASHP) coupled on the air distribution side with a separate novel water heating/dehumidification (WH/DH) module. The motivation for this unusual equipment combination is the forecast trend for home sensible loads to be reduced more than latent loads. Integration of water heating with a space dehumidification cycle addresses humidity control while performing double-duty. This approach can be applied to retrofit/upgrade applications as well as new construction. A WH/DH module capable of ~1.47 L/h water removal and ~2 kW water heating capacity was assembled by the manufacturer. A heat pump system model was used to guide the controls design; lab testing was conducted and used to calibrate the models. Performance maps were generated and used in a TRNSYS sub-hourly simulation to predict annual performance in a well-insulated house. Annual HVAC/WH energy savings of ~35% are predicted in cold and hot-humid U.S. climates compared to a minimum efficiency baseline.

  8. Lunar Surface Stirling Power Systems Using Isotope Heat Sources

    NASA Technical Reports Server (NTRS)

    Schmitz, Paul C.; Penswick, L. Barry; Shaltens, Richard K.

    2010-01-01

    For many years, NASA has used the decay of plutonium-238 (Pu-238) (in the form of the General Purpose Heat Source (GPHS)) as a heat source for Radioisotope Thermoelectric Generators (RTGs), which have provided electrical power for many NASA missions. While RTGs have an impressive reliability record for the missions in which they have been used, their relatively low thermal to electric conversion efficiency and the scarcity of plutonium-238 (Pu-238) has led NASA to consider other power conversion technologies. NASA is considering returning both robotic and human missions to the lunar surface and, because of the long lunar nights (14.75 Earth days), isotope power systems are an attractive candidate to generate electrical power. NASA is currently developing the Advanced Stirling Radioisotope Generator (ASRG) as a candidate higher efficiency power system that produces greater than 160 W with two GPHS modules at the beginning of life (BOL) (32% efficiency). The ASRG uses the same Pu-238 GPHS modules, which are used in RTG, but by coupling them to a Stirling convertor provides a four-fold reduction in the number of GPHS modules. This study considers the use of americium-241 (Am-241) as a substitute for the Pu-238 in Stirling- convertor-based Radioisotope Power Systems (RPS) for power levels from tens of watts to 5 kWe. The Am-241 is used as a substitute for the Pu-238 in GPHS modules. Depending on power level, different Stirling heat input and removal systems are modeled. It was found that substituting Am-241 GPHS modules into the ASRG reduces power output by about one-fifth while maintaining approximately the same system mass. In order to obtain the nominal 160 W of electrical output of the Pu-238 ASRG requires 10 Am-241 GPHS modules. Higher power systems require changing from conductive coupling heat input and removal from the Stirling convertor to either pumped loops or heat pipes. Liquid metal pumped loops are considered as the primary heat transportation on the hot

  9. Synchronization System for Next Generation Light Sources

    SciTech Connect

    Zavriyev, Anton

    2014-03-27

    An alternative synchronization technique – one that would allow explicit control of the pulse train including its repetition rate and delay is clearly desired. We propose such a scheme. Our method is based on optical interferometry and permits synchronization of the pulse trains generated by two independent mode-locked lasers. As the next generation x-ray sources will be driven by a clock signal derived from a mode-locked optical source, our technique will provide a way to synchronize x-ray probe with the optical pump pulses.

  10. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.; Marsala, Joseph

    1994-11-29

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium.

  11. A heat-driven monochromatic light source

    NASA Technical Reports Server (NTRS)

    Stefani, Francis; Lawless, John L.

    1989-01-01

    The efficiency with which heat may be converted into resonance radiation in a cesium thermionic diode is investigated theoretically. An analytical model of a thermionic converter is used which combines the coupled effects of line radiation transport, excited-state kinetics, and plasma diffusion. Operating regimes are established for various degrees of optical density in the plasma. The results indicate that monochromatic radiation can be produced with efficiencies on the order of 30 percent, provided that there is an adequate voltage drop across the plasma. A drop of 1 V was used since it can be maintained without any electrical power input to the device. It is found that high efficiencies are ude to the higher interelectrode distances which the solutions accommodate, and that radiation can be generated efficiently, even with optically dense gases.

  12. Desalination using low grade heat sources

    NASA Astrophysics Data System (ADS)

    Gude, Veera Gnaneswar

    A new, low temperature, energy-efficient and sustainable desalination system has been developed in this research. This system operates under near-vacuum conditions created by exploiting natural means of gravity and barometric pressure head. The system can be driven by low grade heat sources such as solar energy or waste heat streams. Both theoretical and experimental studies were conducted under this research to evaluate and demonstrate the feasibility of the proposed process. Theoretical studies included thermodynamic analysis and process modeling to evaluate the performance of the process using the following alternate energy sources for driving the process: solar thermal energy, solar photovoltaic/thermal energy, geothermal energy, and process waste heat emissions. Experimental studies included prototype scale demonstration of the process using grid power as well as solar photovoltaic/thermal sources. Finally, the feasibility of the process in reclaiming potable-quality water from the effluent of the city wastewater treatment plant was studied. The following results have been obtained from theoretical analysis and modeling: (1) The proposed process can produce up to 8 L/d of freshwater for 1 m2 area of solar collector and evaporation chamber respectively with a specific energy requirement of 3122 kJ for 1 kg of freshwater production. (2) Photovoltaic/thermal (PV/T) energy can produce up to 200 L/d of freshwater with a 25 m2 PV/T module which meets the electricity needs of 21 kWh/d of a typical household as well. This configuration requires a specific energy of 3122 kJ for 1 kg of freshwater production. (3) 100 kg/hr of geothermal water at 60°C as heat source can produce up to 60 L/d of freshwater with a specific energy requirement of 3078 kJ for 1 kg of freshwater production. (4) Waste heat released from an air conditioning system rated at 3.25 kW cooling, can produce up to 125 L/d of freshwater. This configuration requires an additional energy of 208 kJ/kg of

  13. Extremely strong thermohaline sources/sinks generated by diagnostic initialization

    NASA Astrophysics Data System (ADS)

    Chu, Peter C.; Lan, Jian

    2003-03-01

    One difficulty for ocean modeling is the lack of velocity data for specifying the initial condition. Diagnostic initialization is widely used; it integrates the model from known temperature (Tc) and salinity (Sc) and zero velocity fields while holding (Tc, Sc) unchanged. After a period (around 30 days) of the diagnostic run, the velocity field (Vc) is established, and (Tc, Sc, Vc) fields are then treated as the initial conditions for the prognostic numerical modeling. During the diagnostic initialization period, the heat and salt `source/sink' terms are generated at each time step. Maximum time rates of absolute change of the monthly mean T, S (0.1°/day, 0.1 ppt/day) are taken as the standard measures to identify the strength of the thermohaline `sources/sinks'. Twenty four times of the standard measures (0.1°/hr, 0.1 ppt/hr) represent strong `sources/sinks'. Ten times of the strong `sources/sinks' (1°/hr, 1 ppt/hr) represent extremely strong `sources/sinks'. The Princeton Ocean Model implemented for the Japan/East Sea is used to demonstrate the existence of extremely strong thermohaline sources and sinks generated by the diagnostic initialization with the annual mean Tc, Sc from the Navy's Global Digital Environmental Model. The effects of extremely strong and spatially nonuniform initial heating/cooling (salting/freshening) rates on thermohaline and velocity fields need to be further investigated.

  14. Welding Isotopic Heat Sources for the Cassini Mission to Saturn (U)

    SciTech Connect

    Franco-Ferreira, E.A.; George, T.G.

    1995-02-28

    In 1997 NASA will launch the Cassini scientific probe to the planet Saturn. Electric power for this probe will be provided by Radioisotope Thermoelectric Generators thermally driven by General Purpose Heat Source modules.

  15. Infrasound Generation from the Source Physics Experiments

    NASA Astrophysics Data System (ADS)

    Preston, L. A.; Schramm, K. A.; Jones, K. R.

    2015-12-01

    Understanding the acoustic and infrasound source generation mechanisms from underground explosions is of great importance for usage of this unique data type in non-proliferation activities. One of the purposes of the Source Physics Experiments (SPE), a series of underground explosive shots at the Nevada National Security Site (NNSS), is to gain an improved understanding of the generation and propagation of physical signals, such as seismic and infrasound, from the near to far field. Two of the SPE shots (SPE-1 and SPE-4') were designed to be small "Green's Function" sources with minimal spall or permanent surface deformation. We analyze infrasound data collected from these two shots at distances from ~300 m to ~1 km and frequencies up to 20 Hz. Using weather models based upon actual observations at the times of these sources, including 3-D variations in topography, temperatures, pressures, and winds, we synthesized full waveforms using Sandia's moving media acoustic propagation simulation suite. Several source mechanisms were simulated and compared and contrasted with observed waveforms using full waveform source inversion. We will discuss results of these source inversions including the relative roll of spall from these small explosions. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  16. Acoustic source for generating an acoustic beam

    DOEpatents

    Vu, Cung Khac; Sinha, Dipen N.; Pantea, Cristian

    2016-05-31

    An acoustic source for generating an acoustic beam includes a housing; a plurality of spaced apart piezo-electric layers disposed within the housing; and a non-linear medium filling between the plurality of layers. Each of the plurality of piezoelectric layers is configured to generate an acoustic wave. The non-linear medium and the plurality of piezo-electric material layers have a matching impedance so as to enhance a transmission of the acoustic wave generated by each of plurality of layers through the remaining plurality of layers.

  17. Secondary electron ion source neutron generator

    DOEpatents

    Brainard, J.P.; McCollister, D.R.

    1998-04-28

    A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

  18. Secondary electron ion source neutron generator

    DOEpatents

    Brainard, John P.; McCollister, Daryl R.

    1998-01-01

    A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

  19. Thermoelectric generators as self-oscillating heat engines

    NASA Astrophysics Data System (ADS)

    Alicki, Robert

    2016-02-01

    In a previous paper [1] a model of a solar cell was proposed in which the non-periodic source of energy—photon flux—drives the collective periodic motion of electrons in a form of plasma oscillation. Subsequently, plasma oscillations are rectified by the p-n junction diode into dc (work). This approach makes a solar cell similar to standard macroscopic heat motors or turbines which always contain two heat baths, the working medium and the periodically moving piston or rotor. Here, a very similar model is proposed in order to describe the operation principles of thermoelectric generators based either on bimetallic or semiconductor p-n junctions. Again plasma oscillation corresponds to a piston and sunlight is replaced by a hot bath. The mathematical formalism is based on the Markovian master equations which can be derived in a rigorous way from the underlying Hamiltonian models and are consistent with the laws of thermodynamics.

  20. Modelling hot electron generation in short pulse target heating experiments

    NASA Astrophysics Data System (ADS)

    Sircombe, N. J.; Hughes, S. J.

    2013-11-01

    Target heating experiments planned for the Orion laser facility, and electron beam driven fast ignition schemes, rely on the interaction of a short pulse high intensity laser with dense material to generate a flux of energetic electrons. It is essential that the characteristics of this electron source are well known in order to inform transport models in radiation hydrodynamics codes and allow effective evaluation of experimental results and forward modelling of future campaigns. We present results obtained with the particle in cell (PIC) code EPOCH for realistic target and laser parameters, including first and second harmonic light. The hot electron distributions are characterised and their implications for onward transport and target heating are considered with the aid of the Monte-Carlo transport code THOR.

  1. Ground-source Heat Pumps Applied to Commercial Buildings

    SciTech Connect

    Parker, Steven A.; Hadley, Donald L.

    2009-07-14

    Ground-source heat pumps can provide an energy-efficient, cost-effective way to heat and cool commercial facilities. While ground-source heat pumps are well established in the residential sector, their application in larger, commercial-style, facilities is lagging, in part because of a lack of experience with the technology by those in decision-making positions. Through the use of a ground-coupling system, a conventional water-source heat pump design is transformed to a unique means of utilizing thermodynamic properties of earth and groundwater for efficient operation throughout the year in most climates. In essence, the ground (or groundwater) serves as a heat source during winter operation and a heat sink for summer cooling. Many varieties in design are available, so the technology can be adapted to almost any site. Ground-source heat pump systems can be used widely in commercial-building applications and, with proper installation, offer great potential for the commercial sector, where increased efficiency and reduced heating and cooling costs are important. Ground-source heat pump systems require less refrigerant than conventional air-source heat pumps or air-conditioning systems, with the exception of direct-expansion-type ground-source heat pump systems. This chapter provides information and procedures that an energy manager can use to evaluate most ground-source heat pump applications. Ground-source heat pump operation, system types, design variations, energy savings, and other benefits are explained. Guidelines are provided for appropriate application and installation. Two case studies are presented to give the reader a sense of the actual costs and energy savings. A list of manufacturers and references for further reading are included for prospective users who have specific or highly technical questions not fully addressed in this chapter. Sample case spreadsheets are provided in Appendix A. Additional appendixes provide other information on the ground-source

  2. PBMR as an Ideal Heat Source for High-Temperature Process Heat Applications

    SciTech Connect

    Correia, Michael; Greyvenstein, Renee; Silady, Fred; Penfield, Scott

    2006-07-01

    The Pebble Bed Modular Reactor (PBMR) is an advanced helium-cooled, graphite-moderated High Temperature Gas-cooled Reactor (HTGR). A 400 MWt PBMR Demonstration Power Plant (DPP) for the production of electricity is being developed in South Africa. This PBMR technology is also an ideal heat source for process heat applications, including Steam Methane Reforming, steam for Oil Sands bitumen recovery, Hydrogen Production and co-generation (process heat and/or electricity and/or process steam) for petrochemical industries. The cycle configuration used to transport the heat of the reactor to the process plant or to convert the reactor's heat into electricity or steam directly influences the cycle efficiency and plant economics. The choice of cycle configuration depends on the process requirements and is influenced by practical considerations, component and material limitations, maintenance, controllability, safety, performance, risk and cost. This paper provides an overview of the use of a PBMR reactor for process applications and possible cycle configurations are presented for applications which require high temperature process heat and/or electricity. (authors)

  3. Irregular spacing of heat sources for treating hydrocarbon containing formations

    DOEpatents

    Miller, David Scott; Uwechue, Uzo Philip

    2012-06-12

    A method for treating a hydrocarbon containing formation includes providing heat input to a first section of the formation from one or more heat sources located in the first section. Fluids are produced from the first section through a production well located at or near the center of the first section. The heat sources are configured such that the average heat input per volume of formation in the first section increases with distance from the production well.

  4. Low Temperature Heat Source Utilization Current and Advanced Technology

    SciTech Connect

    Anderson, James H. Jr.; Dambly, Benjamin W.

    1992-06-01

    Once a geothermal heat source has been identified as having the potential for development, and its thermal, physical, and chemical characteristics have been determined, a method of utilization must be decided upon. This compendium will touch upon some of these concerns, and hopefully will provide the reader with a better understanding of technologies being developed that will be applicable to geothermal development in East Africa, as well as other parts of the world. The appendices contain detailed reports on Down-the-Well Turbo Pump, The Vapor-Turbine Cycle for Geothermal Power Generation, Heat Exchanger Design for Geothermal Power Plants, and a Feasibility Study of Combined Power and Water Desalting Plant Using Hot Geothermal Water. [DJE-2005

  5. Hollow-Cathode Source Generates Plasma

    NASA Technical Reports Server (NTRS)

    Deininger, W. D.; Aston, G.; Pless, L. C.

    1989-01-01

    Device generates argon, krypton, or xenon plasma via thermionic emission and electrical discharge within hollow cathode and ejects plasma into surrounding vacuum. Goes from cold start up to full operation in less than 5 s after initial application of power. Exposed to moist air between operations without significant degradation of starting and running characteristics. Plasma generated by electrical discharge in cathode barrel sustained and aided by thermionic emission from emitter tube. Emitter tube does not depend on rare-earth oxides, making it vulnerable to contamination by exposure to atmosphere. Device modified for use as source of plasma in laboratory experiments or industrial processes.

  6. Thulium heat source: IR D project 91-031

    SciTech Connect

    Walter, C.E.; Kammeraad, J.E.; Newman, J.G.; Van Konynenburg, R.; VanSant, J.H.

    1991-04-10

    The goal of the Thulium Heat Source study is to determine the performance capability and evaluate the safety and environmental aspects of a thulium-170 heat source. Our approach is to study parametrically the performance of thulium-170 heat source designs in the power range of 5--50 kW{sub th}. At least three heat source designs will be characterized in this power range and integrated with various power conversion subsystems to assess their performance, mass, and volume. We will determine shielding requirements, and consider the safety and environmental aspects of their use.

  7. Laser Sources for Generation of Ultrasound

    NASA Technical Reports Server (NTRS)

    Wagner, James W.

    1996-01-01

    Two laser systems have been built and used to demonstrate enhancements beyond current technology used for laser-based generation and detection of ultrasound. The first system consisted of ten Nd:YAG laser cavities coupled electronically and optically to permit sequential bursts of up to ten laser pulses directed either at a single point or configured into a phased array of sources. Significant enhancements in overall signal-to-noise ratio for laser ultrasound incorporating this new source system was demonstrated, using it first as a source of narrowband ultrasound and secondly as a phased array source producing large enhanced signal displacements. A second laser system was implemented using ultra fast optical pulses from a Ti:Sapphire laser to study a new method for making laser generated ultrasonic measurements of thin films with thicknesses on the order of hundreds of angstroms. Work by prior investigators showed that such measurements could be made based upon fluctuations in the reflectivity of thin films when they are stressed by an arriving elastic pulse. Research performed using equipment purchased under this program showed that a pulsed interferometric system could be used as well as a piezoreflective detection system to measure pulse arrivals even in thin films with very low piezoreflective coefficients.

  8. The impact of TXV heating on the performance of air-source heat pump in heating mode

    SciTech Connect

    Gao, Zhiming

    2010-01-01

    The paper discusses the strategy of TXV heating, which adds a limited amount of heat on the surface of TXV sensor, to achieve energy saving and low cost in air-source heat pumps. The TXV heating is able to retard the valve closing so as to boost energy saving in heating mode. The testing results demonstrate the appropriate TXV heating achieves a remarkable improvement in COP and thermal comfort. The required heating power is not more than 40w. The additional equipment cost of TXV heating is less than $20. Thus, the strategy of TXV heating is practical from the view of technology and economy.

  9. The Source of Alfven Waves That Heat the Solar Corona

    NASA Technical Reports Server (NTRS)

    Ruzmaikin, A.; Berger, M. A.

    1998-01-01

    We suggest a source for high-frequency Alfven waves invoked in coronal heating and acceleration of the solar wind. The source is associated with small-scale magnetic loops in the chromospheric network.

  10. Thermionic generator module with heat pipes

    SciTech Connect

    Horner-Richardson, K.; Ernst, D.M.

    1993-06-15

    A thermionic converter module is described comprising: a first heat pipe with an annular casing which has a first surface located on an inside surface of the annular casing, at least part of the first surface of the casing of the first heat pipe having constructed upon it a thermionic converter emitter located so that heat will be transferred by conduction from the first heat pipe casing to the thermionic converter emitter; a second heat pipe with a casing which has a second surface, the second surface being located within the first surface of the annular casing of the first heat pipe so that it is surrounded by the first surface; a thermionic converter collector located so as to transfer heat by conduction to the second surface of the casing of the second heat pipe with the thermionic converter collector being adjacent to the thermionic converter emitter but being separated from the thermionic converter emitter by an inter electrode space; and end fitting structures located so that, with the thermionic converter collector and the thermionic converter emitter, they complete an enclosure around the inter electrode space and form an evacuated enclosure within which are located the thermionic converter collector and the thermionic converter emitter.

  11. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration.

  12. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, B.A.; Zawacki, T.S.

    1998-07-21

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use, as the heat transfer medium, the working fluid of the absorption system taken from the generator at a location where the working fluid has a rich liquor concentration. 5 figs.

  13. Generator-absorber-heat exchange heat transfer apparatus and method and use thereof in a heat pump

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-12-03

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium. A combination of weak and rich liquor working solution is used as the heat transfer medium.

  14. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly accomplished by cold biasing the reservoir and using electrical heaters to provide the required control power. Using this method, the loop operating temperature can be controlled within +/- 0.5K. However, because of the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP has been carried out to investigate the effects on the LHP operation when the control temperature sensor is placed on the heat source instead of the reservoir. In these tests, the LHP reservoir is cold-biased and is heated by a control heater. Tests results show that it is feasible to use the heat source temperature for feedback control of the LHP operation. Using this method, the heat source temperature can be maintained within a tight range for moderate and high powers. At low powers, however, temperature oscillations may occur due to interactions among the reservoir control heater power, the heat source mass, and the heat output from the heat source. In addition, the heat source temperature could temporarily deviate from its set point during fast thermal transients. The implication is that more sophisticated feedback control algorithms need to be implemented for LHP transient operation when the heat source temperature is used for feedback control.

  15. Documentation generator application for VHDL source codes

    NASA Astrophysics Data System (ADS)

    Niton, B.; Pozniak, K. T.; Romaniuk, R. S.

    2011-06-01

    The UML, which is a complex system modeling and description technology, has recently been expanding its uses in the field of formalization and algorithmic approach to such systems like multiprocessor photonic, optoelectronic and advanced electronics carriers; distributed, multichannel measurement systems; optical networks, industrial electronics, novel R&D solutions. The paper describes a realization of an application for documenting VHDL source codes. There are presented own novel solution based on Doxygen program which is available on the free license, with accessible source code. The used supporting tools for parser building were Bison and Flex. There are presented the practical results of the documentation generator. The program was applied for exemplary VHDL codes. The documentation generator application is used for design of large optoelectronic and electronic measurement and control systems. The paper consists of three parts which describe the following components of the documentation generator for photonic and electronic systems: concept, MatLab application and VHDL application. This is part three which describes the VHDL application. VHDL is used for behavioral description of the Optoelectronic system.

  16. SCALE ANALYSIS OF CONVECTIVE MELTING WITH INTERNAL HEAT GENERATION

    SciTech Connect

    John Crepeau

    2011-03-01

    Using a scale analysis approach, we model phase change (melting) for pure materials which generate internal heat for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. We show the time scales in which conduction and convection heat transfer dominate.

  17. Consideration of Thermoelectric Power Generation by Using Hot Spring Thermal Energy or Industrial Waste Heat

    NASA Astrophysics Data System (ADS)

    Sasaki, Keiichi; Horikawa, Daisuke; Goto, Koichi

    2015-01-01

    Today, we face some significant environmental and energy problems such as global warming, urban heat island, and the precarious balance of world oil supply and demand. However, we have not yet found a satisfactory solution to these problems. Waste heat recovery is considered to be one of the best solutions because it can improve energy efficiency by converting heat exhausted from plants and machinery to electric power. This technology would also prevent atmospheric temperature increases caused by waste heat, and decrease fossil fuel consumption by recovering heat energy, thus also reducing CO2 emissions. The system proposed in this research generates electric power by providing waste heat or unharnessed thermal energy to built-in thermoelectric modules that can convert heat into electric power. Waste heat can be recovered from many places, including machinery in industrial plants, piping in electric power plants, waste incineration plants, and so on. Some natural heat sources such as hot springs and solar heat can also be used for this thermoelectric generation system. The generated power is expected to be supplied to auxiliary machinery around the heat source, stored as an emergency power supply, and so on. The attributes of this system are (1) direct power generation using hot springs or waste heat; (2) 24-h stable power generation; (3) stand-alone power system with no noise and no vibration; and (4) easy maintenance attributed to its simple structure with no moving parts. In order to maximize energy use efficiency, the temperature difference between both sides of the thermoelectric (TE) modules built into the system need to be kept as large as possible. This means it is important to reduce thermal resistance between TE modules and heat source. Moreover, the system's efficiency greatly depends on the base temperature of the heat sources and the material of the system's TE modules. Therefore, in order to make this system practical and efficient, it is necessary to

  18. Loop Heat Pipe Operation Using Heat Source Temperature for Set Point Control

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    Loop heat pipes (LHPs) have been used for thermal control of several NASA and commercial orbiting spacecraft. The LHP operating temperature is governed by the saturation temperature of its compensation chamber (CC). Most LHPs use the CC temperature for feedback control of its operating temperature. There exists a thermal resistance between the heat source to be cooled by the LHP and the LHP's CC. Even if the CC set point temperature is controlled precisely, the heat source temperature will still vary with its heat output. For most applications, controlling the heat source temperature is of most interest. A logical question to ask is: "Can the heat source temperature be used for feedback control of the LHP operation?" A test program has been implemented to answer the above question. Objective is to investigate the LHP performance using the CC temperature and the heat source temperature for feedback control

  19. Heat transfer in a thermoelectric generator for diesel engines

    SciTech Connect

    Bass, J.C.

    1995-12-31

    This paper discusses the design and test results obtained for a 1kW thermoelectric generator used to convert the waste thermal energy in the exhaust of a Diesel engine directly to electric energy. The paper focuses on the heat transfer within the generator and shows what had to be done to overcome the heat transfer problems encountered in the initial generator testing to achieve the output goal of 1kW electrical. The 1kW generator uses Bismuth-Telluride thermoelectric modules for the energy conversion process. These modules are also being evaluated for other waste heat applications. Some of these applications are briefly addressed.

  20. General-Purpose Heat Source safety verification test series: SVT-1 through SVT-6

    SciTech Connect

    Pavone, D.; George, T.G.; Frantz, C.E.

    1985-06-01

    The General-Purpose Heat Source (GPHS) is a modular heat source that will supply energy for Radioisotope Thermoelectric Generators (RTGs) in space missions. The Safety Verification Tests (SVTs) are performed to assess the plutonia containment capability of heat source modules subjected to certain accident environments. This interim report described the GPHS module configuration, the test environment, and the response of the module components following simulated reentry and solid Earth impact. The specific test environment of these initial six tests results from failure of the booster rocket to place the spacecraft in a proper trajectory and subsequent reentry of the GPHS modules from Earth orbit. 36 figs.

  1. General-Purpose Heat Source safety verification test series: SVT-1 through SVT-6

    NASA Astrophysics Data System (ADS)

    Pavone, D.; George, T. G.; Frantz, C. E.

    1985-06-01

    The General-Purpose Heat Source (GPHS) is a modular heat source that will supply energy for Radioisotope Thermoelectric Generators (RTGs) in space missions. The Safety Verification Tests (SVTs) are performed to assess the plutonium containment capability of heat source modules subjected to certain accident environments. This interim report described the GPHS module configuration, the test environment, and the response of the module components following simulated reentry and solid Earth impact. The specific test environment of these initial six tests results from failure of the booster rocket to place the spacecraft in a proper trajectory and subsequent reentry of the GPHS modules from Earth orbit.

  2. An Empirical Temperature Variance Source Model in Heated Jets

    NASA Technical Reports Server (NTRS)

    Khavaran, Abbas; Bridges, James

    2012-01-01

    An acoustic analogy approach is implemented that models the sources of jet noise in heated jets. The equivalent sources of turbulent mixing noise are recognized as the differences between the fluctuating and Favre-averaged Reynolds stresses and enthalpy fluxes. While in a conventional acoustic analogy only Reynolds stress components are scrutinized for their noise generation properties, it is now accepted that a comprehensive source model should include the additional entropy source term. Following Goldstein s generalized acoustic analogy, the set of Euler equations are divided into two sets of equations that govern a non-radiating base flow plus its residual components. When the base flow is considered as a locally parallel mean flow, the residual equations may be rearranged to form an inhomogeneous third-order wave equation. A general solution is written subsequently using a Green s function method while all non-linear terms are treated as the equivalent sources of aerodynamic sound and are modeled accordingly. In a previous study, a specialized Reynolds-averaged Navier-Stokes (RANS) solver was implemented to compute the variance of thermal fluctuations that determine the enthalpy flux source strength. The main objective here is to present an empirical model capable of providing a reasonable estimate of the stagnation temperature variance in a jet. Such a model is parameterized as a function of the mean stagnation temperature gradient in the jet, and is evaluated using commonly available RANS solvers. The ensuing thermal source distribution is compared with measurements as well as computational result from a dedicated RANS solver that employs an enthalpy variance and dissipation rate model. Turbulent mixing noise predictions are presented for a wide range of jet temperature ratios from 1.0 to 3.20.

  3. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source.

    PubMed

    Kim, June Young; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae; Hwang, Y S

    2016-02-01

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H(-) ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H(-) ion generation in volume-produced negative hydrogen ion sources. PMID:26931999

  4. Electron cyclotron resonance heating by magnetic filter field in a negative hydrogen ion source.

    PubMed

    Kim, June Young; Cho, Won-Hwi; Dang, Jeong-Jeung; Chung, Kyoung-Jae; Hwang, Y S

    2016-02-01

    The influence of magnetic filter field on plasma properties in the heating region has been investigated in a planar-type inductively coupled radio-frequency (RF) H(-) ion source. Besides filtering high energy electrons near the extraction region, the magnetic filter field is clearly observed to increase the electron temperature in the heating region at low pressure discharge. With increasing the operating pressure, enhancement of electron temperature in the heating region is reduced. The possibility of electron cyclotron resonance (ECR) heating in the heating region due to stray magnetic field generated by a filter magnet located at the extraction region is examined. It is found that ECR heating by RF wave field in the discharge region, where the strength of an axial magnetic field is approximately ∼4.8 G, can effectively heat low energy electrons. Depletion of low energy electrons in the electron energy distribution function measured at the heating region supports the occurrence of ECR heating. The present study suggests that addition of axial magnetic field as small as several G by an external electromagnet or permanent magnets can greatly increase the generation of highly ro-vibrationally excited hydrogen molecules in the heating region, thus improving the performance of H(-) ion generation in volume-produced negative hydrogen ion sources.

  5. HeatWave: the next generation of thermography devices

    NASA Astrophysics Data System (ADS)

    Moghadam, Peyman; Vidas, Stephen

    2014-05-01

    Energy sustainability is a major challenge of the 21st century. To reduce environmental impact, changes are required not only on the supply side of the energy chain by introducing renewable energy sources, but also on the demand side by reducing energy usage and improving energy efficiency. Currently, 2D thermal imaging is used for energy auditing, which measures the thermal radiation from the surfaces of objects and represents it as a set of color-mapped images that can be analysed for the purpose of energy efficiency monitoring. A limitation of such a method for energy auditing is that it lacks information on the geometry and location of objects with reference to each other, particularly across separate images. Such a limitation prevents any quantitative analysis to be done, for example, detecting any energy performance changes before and after retrofitting. To address these limitations, we have developed a next generation thermography device called Heat Wave. Heat Wave is a hand-held 3D thermography device that consists of a thermal camera, a range sensor and color camera, and can be used to generate precise 3D model of objects with augmented temperature and visible information. As an operator holding the device smoothly waves it around the objects of interest, Heat Wave can continuously track its own pose in space and integrate new information from the range and thermal and color cameras into a single, and precise 3D multi-modal model. Information from multiple viewpoints can be incorporated together to improve the accuracy, reliability and robustness of the global model. The approach also makes it possible to reduce any systematic errors associated with the estimation of surface temperature from the thermal images.

  6. Ground Source Heat Pump Computational Results

    DOE Data Explorer

    James Menart

    2013-07-31

    This data submission includes simulation results for ground loop heat pump systems located in 6 different cities across the United States. The cities are Boston, MA, Dayton, OH, Omaha, NE, Orlando, FL, Sacramento, CA, and St. Paul, MN. These results were obtained from the two-dimensional geothermal computer code called GEO2D. GEO2D was written as part of this DOE funded grant. The results included in this submission for each of the 6 cities listed above are: 1) specific information on the building being heated or cooled by the ground loop geothermal system, 2) some extreme values for the building heating and cooling loads during the year, 3) the inputs required to carry out the simulation, 4) a plot of the hourly building heating and cooling loads throughout the year, 5) a plot of the fluid temperature exiting the ground loop for a 20 year period, 6) a plot of the heat exchange between the ground loop and the ground for a 20 year period, and 7) ground and ground loop temperature contour plots at different times of the year for the 20 year period.

  7. Design of isotope heat source for automatic modular dispersal during reentry, and its integration with heat exchangers of 6-kWe dynamic isotope power system

    NASA Astrophysics Data System (ADS)

    Schock, Alfred

    An account is given of the results of a design study for a single heat source dynamic isotope power system (DIPS) of about 30 kW(t), using the standard 250 W general purpose heat source modules previously devised for radioisotope thermoelectric generators. Attention is given to the scheme devised for holding the individual heat source modules together during launch, which automatically releases them during reentry to minimize their impact velocity. The heat source design also contains passive provisions against overheating, in case active cooling is lost.

  8. Ground Source Integrated Heat Pump (GS-IHP) Development

    SciTech Connect

    Baxter, V. D.; Rice, K.; Murphy, R.; Munk, J.; Ally, Moonis; Shen, Bo; Craddick, William; Hearn, Shawn A.

    2013-05-24

    Between October 2008 and May 2013 ORNL and ClimateMaster, Inc. (CM) engaged in a Cooperative Research and Development Agreement (CRADA) to develop a groundsource integrated heat pump (GS-IHP) system for the US residential market. A initial prototype was designed and fabricated, lab-tested, and modeled in TRNSYS (SOLAR Energy Laboratory, et al, 2010) to predict annual performance relative to 1) a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of air-source heat pump (ASHP) and resistance water heater) and 2) a state-of-the-art (SOA) two-capacity ground-source heat pump with desuperheater water heater (WH) option (GSHPwDS). Predicted total annual energy savings, while providing space conditioning and water heating for a 2600 ft{sup 2} (242 m{sup 2}) house at 5 U.S. locations, ranged from 52 to 59%, averaging 55%, relative to the minimum efficiency suite. Predicted energy use for water heating was reduced 68 to 78% relative to resistance WH. Predicted total annual savings for the GSHPwDS relative to the same baseline averaged 22.6% with water heating energy use reduced by 10 to 30% from desuperheater contributions. The 1st generation (or alpha) prototype design for the GS-IHP was finalized in 2010 and field test samples were fabricated for testing by CM and by ORNL. Two of the alpha units were installed in 3700 ft{sup 2} (345 m{sup 2}) houses at the ZEBRAlliance site in Oak Ridge and field tested during 2011. Based on the steady-state performance demonstrated by the GS-IHPs it was projected that it would achieve >52% energy savings relative to the minimum efficiency suite at this specific site. A number of operational issues with the alpha units were identified indicating design changes needed to the system before market introduction could be accomplished. These were communicated to CM throughout the field test period. Based on the alpha unit test results and the diagnostic information coming from the field test

  9. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  10. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  11. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  12. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  13. 10 CFR 39.55 - Tritium neutron generator target sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Tritium neutron generator target sources. 39.55 Section 39... Equipment § 39.55 Tritium neutron generator target sources. (a) Use of a tritium neutron generator target...) Use of a tritium neutron generator target source, containing quantities exceeding 1,110 GBg or in...

  14. Environmental assessment for radioisotope heat source fuel processing and fabrication

    SciTech Connect

    Not Available

    1991-07-01

    DOE has prepared an Environmental Assessment (EA) for radioisotope heat source fuel processing and fabrication involving existing facilities at the Savannah River Site (SRS) near Aiken, South Carolina and the Los Alamos National Laboratory (LANL) near Los Alamos, New Mexico. The proposed action is needed to provide Radioisotope Thermoelectric Generators (RTG) to support the National Aeronautics and Space Administration's (NASA) CRAF and Cassini Missions. Based on the analysis in the EA, DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, an Environmental Impact Statement is not required. 30 refs., 5 figs.

  15. Residential Solar Combined Heat and Power Generation using Solar Thermoelectric Generation

    NASA Astrophysics Data System (ADS)

    Ohara, B.; Wagner, M.; Kunkle, C.; Watson, P.; Williams, R.; Donohoe, R.; Ugarte, K.; Wilmoth, R.; Chong, M. Zachary; Lee, H.

    2015-06-01

    Recent reports on improved efficiencies of solar thermoelectric generation (STEG) systems have generated interest in STEGs as a competitive power generation system. In this paper, the design of a combined cooling and power utilizing concentrated solar power is discussed. Solar radiation is concentrated into a receiver connected to thermoelectric modules, which are used as a topping cycle to generate power and high grade heat necessary to run an absorption chiller. Modeling of the overall system is discussed with experimental data to validate modeling results. A numerical modeling approach is presented which considers temperature variation of the source and sink temperatures and is used to maximize combined efficiency. A system is built with a demonstrated combined efficiency of 32% in actual working conditions with power generation of 3.1 W. Modeling results fell within 3% of the experimental results verifying the approach. An optimization study is performed on the mirror concentration ration and number of modules for thermal load matching and is shown to improve power generation to 26.8 W.

  16. Field ion source development for neutron generators

    NASA Astrophysics Data System (ADS)

    Bargsten Johnson, B.; Schwoebel, P. R.; Holland, C. E.; Resnick, P. J.; Hertz, K. L.; Chichester, D. L.

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption (˜20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with ˜10,000 tip arrays have achieved deuterium ion currents of ˜50 nA. Neutron production by field ionization has yielded ˜10 2 n/s from ˜1 mm 2 of array area using the deuterium-deuterium fusion reaction at 90 kV.

  17. Field Ion Source Development for Neutron Generators

    SciTech Connect

    B. Bargsten Johnson; P. R. Schwoebel; C. E. Holland; P. J. Resnick; K. L. Hertz; D. L. Chichester

    2012-01-01

    An ion source based on the principles of electrostatic field desorption is being developed to improve the performance of existing compact neutron generators. The ion source is an array of gated metal tips derived from field electron emitter array microfabrication technology. A comprehensive summary of development and experimental activities is presented. Many structural modifications to the arrays have been incorporated to achieve higher tip operating fields, while lowering fields at the gate electrode to prevent gate field electron emission which initiates electrical breakdown in the array. The latest focus of fabrication activities has been on rounding the gate electrode edge and surrounding the gate electrode with dielectric material. Array testing results have indicated a steady progression of increased array tip operating fields with each new design tested. The latest arrays have consistently achieved fields beyond those required for the onset of deuterium desorption ({approx}20 V/nm), and have demonstrated the desorption of deuterium at fields up to 36 V/nm. The number of ions desorbed from an array has been quantified, and field desorption of metal tip substrate material from array tips has been observed for the first time. Gas-phase field ionization studies with {approx}10,000 tip arrays have achieved deuterium ion currents of {approx}50 nA. Neutron production by field ionization has yielded {approx}10{sup 2} n/s from {approx}1 mm{sup 2} of array area using the deuterium-deuterium fusion reaction at 90 kV.

  18. Arena retrofit includes ground-source heat pump

    SciTech Connect

    Hodgson, S.F.

    1996-01-01

    The venue for Sacramento`s first professional basketball games was the {open_quotes}old Arco Arena,{close_quotes} built in 1985 just north of the downtown area and converted to offices after a large, permanent arena was constructed. In 1994, the {open_quotes}old arena{close_quotes} was acquired by a California general partnership called Del Paso Venture. To heat and cool the 3-story, 211,000-square foot structure, Del Paso has installed a ground-source heat pump system. The project is significant for the ground-source heat pump industry, because this is the first ground-source heat pump site ever designed specifically for the energy load of the building it will serve. Other projects have been calculated by rule-of-thumb. The installation and cost of the heat pump system are discussed.

  19. Solid–Liquid Phase Change Driven by Internal Heat Generation

    SciTech Connect

    John Crepeau; Ali s. Siahpush

    2012-07-01

    This article presents results of solid-liquid phase change, the Stefan Problem, where melting is driven internal heat generation, in a cylindrical geometry. The comparison between a quasi-static analytical solution for Stefan numbers less than one and numerical solutions shows good agreement. The computational results of phase change with internal heat generation show how convection cells form in the liquid region. A scale analysis of the same problem shows four distinct regions of the melting process.

  20. Optimization of the Heat Exchangers of a Thermoelectric Generation System

    NASA Astrophysics Data System (ADS)

    Martínez, A.; Vián, J. G.; Astrain, D.; Rodríguez, A.; Berrio, I.

    2010-09-01

    The thermal resistances of the heat exchangers have a strong influence on the electric power produced by a thermoelectric generator. In this work, the heat exchangers of a thermoelectric generator have been optimized in order to maximize the electric power generated. This thermoelectric generator harnesses heat from the exhaust gas of a domestic gas boiler. Statistical design of experiments was used to assess the influence of five factors on both the electric power generated and the pressure drop in the chimney: height of the generator, number of modules per meter of generator height, length of the fins of the hot-side heat exchanger (HSHE), length of the gap between fins of the HSHE, and base thickness of the HSHE. The electric power has been calculated using a computational model, whereas Fluent computational fluid dynamics (CFD) has been used to obtain the thermal resistances of the heat exchangers and the pressure drop. Finally, the thermoelectric generator has been optimized, taking into account the restrictions on the pressure drop.

  1. Thulium heat source IR D Project 91-031

    SciTech Connect

    Walter, C.E.; Kammeraad, J.E.; Newman, J.G.; Van Konynenburg, R.; VanSant, J.H.

    1991-01-01

    The goal of the Thulium Heat Source study is to determine the performance capability and evaluate the safety and environmental aspects of a thulium-170 heat source. Thulium-170 has several attractive features, including the fact that it decays to a stable, chemically innocuous isotope in a relatively short time. A longer-range goal is to attract government funding for the development, fabrication, and demonstration testing in an Autonomous Underwater Vehicle (AUV) of one or more thulium isotope power (TIP) prototype systems. The approach is to study parametrically the performance of thulium-170 heat source designs in the power range of 5-50 kW{sub th}. At least three heat source designs will be characterized in this power range to assess their performance, mass, and volume. The authors will determine shielding requirements, and consider the safety and environmental aspects of their use.

  2. Heat-operated cryogenic electrical generator

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Saffren, M. M.; Elleman, D. D.

    1975-01-01

    Generator operation is based upon unusual hydrodynamic properties exhibited by liquid helium below superfluid critical point. Below that temperature, liquid behaves as though it is mixture of two interpenetrating fluids. When transition takes place between superfluid and normal states, conservation of momentum is always balanced by normal fluid.

  3. Prospects for using high power x-rays as a volumetric heat source

    SciTech Connect

    Rosenberg, R.A.; Farrell, W.; Ma, Q.

    1997-09-01

    Third-generation, high-intensity, x-ray synchrotron radiation sources are capable of producing high heat-flux x-ray beams. In many applications finding ways to handle these powers is viewed as a burden. However, there are some technological applications where the deep penetration length of the x-rays may find beneficial uses as a volumetric heat source. In this paper the authors discuss the prospects for using high power x-rays for volumetric heating and report some recent experimental results. The particular applications they focus on are welding and surface heat treatment. The radiation source is an undulator at the Advanced Photon Source (APS). Results of preliminary tests on aluminum, aluminum metal matrix composites, and steel will be presented.

  4. Tests confirm gas heat as monoxide source

    SciTech Connect

    Besch, E.

    1984-03-01

    Six tests were conducted to demonstrate the potential for natural gas or oil-fired forced warm air heating equipment to produce carbon monoxide emission when the combustion process is impeded by typical causes found in households. In the case of the gas-fired units, impeded combustion produced a smell of aldehyde and various levels of carbon monoxide emission; all within the level dangerous to health. It was concluded that oil-fired warm air systems do not pose a carbon monoxide danger but that natural gas warm air systems do pose a real danger and should be so identified.

  5. On effectiveness and entropy generation in heat exchanger

    NASA Astrophysics Data System (ADS)

    Xiong, Daxi; Li, Zhixin; Guo, Zengyuan

    1996-12-01

    Some conceptual problems were discussed in the present paper. Firstly, according to the physical meaning of effectiveness, a new expression of effectiveness was developed by using an ideal heat exchanger model and temperature histogram method, in which the non-uniform inlet temperature profile was considered. Secondly, the relation of entropy generation number to effectiveness was studied, it was pointed out that both of them could express the perfect degree of a heat exchanger to the second thermodynamic law. Finally, to describe both quantity and quality of heat transferred in a heat exchanger, a criterion named as comprehensive thermal performance coefficient (CTPE) was presented.

  6. Nuclear heat source component design considerations for HTGR process heat reactor plant concept

    SciTech Connect

    McDonald, C.F.; Kapich, D.; King, J.H.; Venkatesh, M.C.

    1982-05-01

    The coupling of a high-temperature gas-cooled reactor (HTGR) and a chemical process facility has the potential for long-term synthetic fuel production (i.e., oil, gasoline, aviation fuel, hydrogen, etc) using coal as the carbon source. Studies are in progress to exploit the high-temperature capability of an advanced HTGR variant for nuclear process heat. The process heat plant discussed in this paper has a 1170-MW(t) reactor as the heat source and the concept is based on indirect reforming, i.e., the high-temperature nuclear thermal energy is transported (via an intermediate heat exchanger (IHX)) to the externally located process plant by a secondary helium transport loop. Emphasis is placed on design considerations for the major nuclear heat source (NHS) components, and discussions are presented for the reactor core, prestressed concrete reactor vessel (PCRV), rotating machinery, and heat exchangers.

  7. Design of the 3rd generation ECR ion source

    SciTech Connect

    Lyneis, C.M.; Xie, Z.Q.; Taylor, C.E.

    1997-02-01

    Development of the 3rd Generation ECR ion source has progressed from a concept described in the last ECR Ion Source Workshop to the fabrication of a full scale prototype superconducting magnet structure. The prototype consists of three solenoid coils and six race track coils with iron poles forming the sextupole. The design calls for mirror fields of 4 T at injection and 3 T at extraction and for a radial field strength at the wall of 2.4 T. The prototype magnet will be tested this spring in an existing vertical cryostat to determine its operating characteristics including maximum operating values, training characteristics and to study the interaction between the solenoid and sextupole coils. Design of the ECR plasma chamber includes aluminum walls to provide an enhanced source of cold electrons, up to three separate microwave feeds to allow simultaneous heating of the plasma electrons at 10, 14 and 18 GHz or at 6, 10 and 14 GHz. Water cooling of the plasma chamber walls and the injection and extraction plates is planned so that up to 10 kW of microwave power can be used without excessive heating of the chamber components. Experience with the AECR-U at LBNL shows that increasing the magnetic fields and using two frequency heating allows operation at lower neutral pressures and higher microwave power density. Both of these conditions are needed to produce very high charge states from elements with masses greater than xenon and the resulting higher energy, more intense heavy beams from the 88-Inch Cyclotron would provide new research opportunities.

  8. Characterization of Pu-238 heat source granule containment

    SciTech Connect

    Richardson Ii, P D; Thronas, D L; Romero, J P; Sandoval, F E; Neuman, A D; Duncan, W S

    2008-01-01

    The Milliwatt Radioisotopic Thermoelectric Generator (RTG) provides power for permissive-action links. These nuclear batteries convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of {sup 238}Pu, in the form of {sup 238}PuO{sub 2} granules. The granules are contained in 3 layers of encapsulation. A thin T-111 liner surrounds the {sup 238}PuO{sub 2} granules and protects the second layer (strength member) from exposure to the fuel granules. The T-111 strength member contains the fuel under impact condition. An outer clad of Hastelloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this {sup 238}PuO{sub 2} containment system. Any compromise in the strength member is something that needs to be characterized. Consequently, the T-111 strength member is characterized upon it's decommissioning through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of photomicrographs. SEM may further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray Spectroscopy (EDS). This paper describes the characterization of the metallurgical condition of decommissioned RTG heat sources.

  9. Finned Tube With Vortex Generators For A Heat Exchanger.

    DOEpatents

    Sohal, Manohar S.; O'Brien, James E.

    2005-12-20

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  10. Finned Tube With Vortex Generators For A Heat Exchanger.

    DOEpatents

    Sohal, Monohar S.; O'Brien, James E.

    2004-09-14

    A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

  11. Helium release from radioisotope heat sources

    SciTech Connect

    Peterson, D.E.; Early, J.W.; Starzynski, J.S.; Land, C.C.

    1984-05-01

    Diffusion of helium in /sup 238/PuO/sub 2/ fuel was characterized as a function of the heating rate and the fuel microstructure. The samples were thermally ramped in an induction furnace and the helium release rates measured with an automated mass spectrometer. The diffusion constants and activation energies were obtained from the data using a simple diffusion model. The release rates of helium were correlated with the fuel microstructure by metallographic examination of fuel samples. The release mechanism consists of four regimes, which are dependent upon the temperature. Initially, the release is controlled by movement of point defects combined with trapping along grain boundaries. This regime is followed by a process dominated by formation and growth of helium bubbles along grain boundaries. The third regime involves volume diffusion controlled by movement of oxygen vacancies. Finally, the release at the highest temperatures follows the diffusion rate of intragranular bubbles. The tendency for helium to be trapped within the grain boundaries diminishes with small grain sizes, slow thermal pulses, and older fuel.

  12. Numerical and Experimental Investigation for Heat Transfer Enhancement by Dimpled Surface Heat Exchanger in Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Wang, Yiping; Li, Shuai; Yang, Xue; Deng, Yadong; Su, Chuqi

    2016-03-01

    For vehicle thermoelectric exhaust energy recovery, the temperature difference between the heat exchanger and the coolant has a strong influence on the electric power generation, and ribs are often employed to enhance the heat transfer of the heat exchanger. However, the introduction of ribs will result in a large unwanted pressure drop in the exhaust system which is unfavorable for the engine's efficiency. Therefore, how to enhance the heat transfer and control the pressure drop in the exhaust system is quite important for thermoelectric generators (TEG). In the current study, a symmetrical arrangement of dimpled surfaces staggered in the upper and lower surfaces of the heat exchanger was proposed to augment heat transfer rates with minimal pressure drop penalties. The turbulent flow characteristics and heat transfer performance of turbulent flow over the dimpled surface in a flat heat exchanger was investigated by numerical simulation and temperature measurements. The heat transfer capacity in terms of Nusselt number and the pressure loss in terms of Fanning friction factors of the exchanger were compared with those of the flat plate. The pressure loss and heat transfer characteristics of dimples with a depth-to-diameter ratio ( h/D) at 0.2 were investigated. Finally, a quite good heat transfer performance with minimal pressure drop heat exchanger in a vehicle TEG was obtained. And based on the area-averaged surface temperature of the heat exchanger and the Seeback effect, the power generation can be improved by about 15% at Re = 25,000 compared to a heat exchanger with a flat surface.

  13. Effectiveness of an ammonia-water mixture turbine system to hot water heat source

    SciTech Connect

    Suzuki, Takashi; Noguchi, Hideki; Amano, Yoshiharu; Hashizume, Takumi; Akiba, Masashi; Tanzawa, Yoshiaki; Usui, Akira

    1999-07-01

    An ammonia-water mixture (AWM) turbine system is proposed in the paper. The authors call this Waseda ammonia-water Mixture Turbine System (W-MTS). The paper presents some results of the investigation for design of a bottoming cycle that is supplied steam as heat source. The results of the cycle simulation show that the W-MTS is superior to the other simple Kalina cycles (KCS1 and KCS34) to pressurized hot water and steam as a latent and a sensible heat source at a temperature of 160 C. The main components of the W-MTS are a heat recovery vapor generator, two condensers, an AWM turbine and two separators. The W-MTS features two simple Kalina cycles, KCS-1 and KCS-34. The W-MTS behaves like KCS-1 at low ammonia mass fraction region, and like KCS-34 at high ammonia mass fraction region. The W-MTS shows the higher output power rather than the two simple Kalina cycles at all over the ammonia mass fraction. The W-MTS is expected to be effective with the heat recovery of two preheaters in a AWM-vapor generation not only to sensible heat sources, such as exhaust gas that comes from gas turbine, hot water from a waste heat recovery system, etc., but also latent heat source e.g. steam. The results of the simulation show that the ammonia mass fraction at the inlet of the heat recovery vapor generator, turbine inlet pressure and temperature in the separator are the key parameters for optimizing the operating conditions of the cycles. In the temperature rage between 120 C and 200 C, the W-MTS generates more power rather than two simple Kaline cycles.

  14. local alternative sources for cogeneration combined heat and power system

    NASA Astrophysics Data System (ADS)

    Agll, Abdulhakim Amer

    Global demand for energy continues to grow while countries around the globe race to reduce their reliance on fossil fuels and greenhouse gas emissions by implementing policy measures and advancing technology. Sustainability has become an important issue in transportation and infrastructure development projects. While several agencies are trying to incorporate a range of sustainability measures in their goals and missions, only a few planning agencies have been able to implement these policies and they are far from perfect. The low rate of success in implementing sustainable policies is primarily due to incomplete understanding of the system and the interaction between various elements of the system. The conventional planning efforts focuses mainly on performance measures pertaining to the system and its impact on the environment but seldom on the social and economic impacts. The objective of this study is to use clean and alternative energy can be produced from many sources, and even use existing materials for energy generation. One such pathway is using wastewater, animal and organic waste, or landfills to create biogas for energy production. There are three tasks for this study. In topic one evaluated the energy saving that produced from combined hydrogen, heat, and power and mitigate greenhouse gas emissions by using local sustainable energy at the Missouri S&T campus to reduce energy consumption and fossil fuel usage. Second topic aimed to estimate energy recovery and power generation from alternative energy source by using Rankin steam cycle from municipal solid waste at Benghazi-Libya. And the last task is in progress. The results for topics one and two have been presented.

  15. Infant respiratory symptoms associated with indoor heating sources.

    PubMed

    Triche, Elizabeth W; Belanger, Kathleen; Beckett, William; Bracken, Michael B; Holford, Theodore R; Gent, Janneane; Jankun, Thomas; McSharry, Jean-Ellen; Leaderer, Brian P

    2002-10-15

    This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants.

  16. Infant respiratory symptoms associated with indoor heating sources.

    PubMed

    Triche, Elizabeth W; Belanger, Kathleen; Beckett, William; Bracken, Michael B; Holford, Theodore R; Gent, Janneane; Jankun, Thomas; McSharry, Jean-Ellen; Leaderer, Brian P

    2002-10-15

    This study examined the effects of indoor heating sources on infant respiratory symptoms during the heating season of the first year of life. Mothers delivering babies between 1993 and 1996 at 12 hospitals in Connecticut and Virginia were enrolled. Daily symptom and heating source use information about their infant was obtained every 2 weeks during the first year of life. Heating sources included fireplace, wood stove, kerosene heater, and gas space heater use. Four health outcomes were analyzed by reporting period: days of wheeze, episodes of wheeze, days of cough, and episodes of cough. A large percentage of infants had at least one episode of cough (88%) and wheeze (33%) during the heating season of the first year of life. Wood stove, fireplace, kerosene heater, and gas space heater use was intermittent across the study period. In adjusted Poisson regression models controlling for important confounders, gas space heater use was associated with episodes and days of wheeze. Wood stove use was associated with total days of cough, and kerosene heater use was associated with episodes of cough. Fireplace use was not associated with any of the respiratory symptoms. Use of some heating sources appears related to respiratory symptoms in infants. PMID:12379555

  17. Effect on Non-Uniform Heat Generation on Thermionic Reactions

    SciTech Connect

    Schock, Alfred

    2012-01-19

    The penalty resulting from non-uniform heat generation in a thermionic reactor is examined. Operation at sub-optimum cesium pressure is shown to reduce this penalty, but at the risk of a condition analogous to burnout. For high pressure diodes, a simple empirical correlation between current, voltage and heat flux is developed and used to analyze the performance penalty associated with two different heat flux profiles, for series-and parallel-connected converters. The results demonstrate that series-connected converters require much finer power flattening than parallel converters. For example, a ±10% variation in heat generation across a series array can result in a 25 to 50% power penalty.

  18. Recuperator with microjet technology as a proposal for heat recovery from low-temperature sources

    NASA Astrophysics Data System (ADS)

    Wajs, Jan; Mikielewicz, Dariusz; Fornalik-Wajs, Elżbieta; Bajor, Michał

    2015-12-01

    A tendency to increase the importance of so-called dispersed generation, based on the local energy sources and the working systems utilizing both the fossil fuels and the renewable energy resources is observed nowadays. Generation of electricity on industrial or domestic scale together with production of heat can be obtained for example through employment of the ORC systems. It is mentioned in the EU directive 2012/27/EU for cogenerative production of heat and electricity. For such systems the crucial points are connected with the heat exchangers, which should be small in size but be able to transfer high heat fluxes. In presented paper the prototype microjet heat exchanger dedicated for heat recovery systems is introduced. Its novel construction is described together with the systematical experimental analysis of heat transfer and flow characteristics. Reported results showed high values of the overall heat transfer coefficient and slight increase in the pressure drop. The results of microjet heat exchanger were compared with the results of commercially available compact plate heat exchanger.

  19. An alternative energy source utilization with an MHD generator

    SciTech Connect

    Bityurin, V.A.

    1995-12-31

    One of the main goal of the MHD generators development is to increase an efficiency of electrical power generation systems and, as a consequence, to reduce an fossil fuel consumption. It is well known now that earth fossil fuel resources are rather limited and especially the oil and natural gas being the most valuable fossil fuel are predicted to be exhausted in several decades. The coal resources are much more huge and can serve as main energy source for another century. For this reason besides so called renewable energy sources the nuclear both fission and fusion is considered as the first candidate for the future. This prospective looks not very much desirable due to very heavy problem in large scale radioactive waste removal from the Earth. From this point of view a search for alternative energy sources available for commercial scale electrical power production is still actual. On our opinion among usually accounted energy sources one of the most huge one is not presented. This is an energy of any mass located in the gravitational field of the Earth. Such a mass infinitely distant from the Earth has a potential of about 62 MJ/kg which is significantly higher then for any fossil fuel-oxidizer system. The nearest natural huge storage of such a type is the Moon with the total amount of energy {approximately}5x10{sup 30} which is of two order of magnitude greater than nuclear energy stored in all deuterium in the ocean. One possible way to use this energy is to bring the moon mass into the upper atmosphere of the Earth and to convert this energy into electricity with an MHD generator working on external air flow heated by the interaction of moving mass with atmospheric air. It should be noted that in contrast to the conventional MHD generator considered earlier for fossil fuel utilization the space based MHD generator deals with much higher enthalpy flux and, consequently, the enthalpy extraction ratio could be also much higher.

  20. Feasibility of drying system using waste heat as the heating source

    NASA Astrophysics Data System (ADS)

    Xie, M. N.; Shi, Y. L.; Chen, L. X.

    2016-08-01

    In this study, a wastewater heat pump system was proposed and its thermal performance was analyzed. The proposed system includes two evaporators: an air-source evaporator and a water-source evaporator. The air-source evaporator absorbs heat from the moist hot air which exhaust from the drying oven. The water-source evaporator absorbs heat from the waste water, while the waste water recovers heat from the mechanical energy, which was produced by cutting and polishing in stone production. The thermodynamic model was developed to evaluate the performance of the proposed system. The energetic analysis was carried out to investigate the influences of the temperature of fresh air. The results show significantly higher energy efficiency, compact-sized and energy-saving compared with the system which uses air as the heat source. Among the seven of alternative refrigerants (R152a, R123, R1234yf, R1234ze, R600a, R22 and R600) investigated, R123 was suggested to be used in this heat pump for its high heating efficiency, inflammable, very low ODP(Ozone Depletion Potential) and GWP(Global warming potential).

  1. Diffusion of Heat from a Line Source in Isotropic Turbulence

    NASA Technical Reports Server (NTRS)

    Uberoi, Mahinder S; Corrsin, Stanley

    1953-01-01

    An experimental and analytical study has been made of some features of the turbulent heat diffusion behind a line heated wire stretched perpendicular to a flowing isotropic turbulence. The mean temperature distributions have been measured with systematic variations in wind speed, size of turbulence-producing grid, and downstream location of heat source. The nature of the temperature fluctuation field has been studied. A comparison of Lagrangian and Eulerian analyses for diffusion in a nondecaying turbulence yields an expression for turbulent-heat-transfer coefficient in terms of turbulence velocity and a Lagrangian "scale." the ratio of Eulerian to Lagrangian microscale has been determined theoretically by generalization of a result of Heisenberg and with arbitrary constants taken from independent sources, shows rough agreement with experimental results. A convenient form has been deduced for the criterion of interchangeability of instantaneous space and time derivatives in a flowing turbulence.

  2. Hydrous mineral dehydration around heat-generating nuclear waste in bedded salt formations.

    PubMed

    Jordan, Amy B; Boukhalfa, Hakim; Caporuscio, Florie A; Robinson, Bruce A; Stauffer, Philip H

    2015-06-01

    Heat-generating nuclear waste disposal in bedded salt during the first two years after waste emplacement is explored using numerical simulations tied to experiments of hydrous mineral dehydration. Heating impure salt samples to temperatures of 265 °C can release over 20% by mass of hydrous minerals as water. Three steps in a series of dehydration reactions are measured (65, 110, and 265 °C), and water loss associated with each step is averaged from experimental data into a water source model. Simulations using this dehydration model are used to predict temperature, moisture, and porosity after heating by 750-W waste canisters, assuming hydrous mineral mass fractions from 0 to 10%. The formation of a three-phase heat pipe (with counter-circulation of vapor and brine) occurs as water vapor is driven away from the heat source, condenses, and flows back toward the heat source, leading to changes in porosity, permeability, temperature, saturation, and thermal conductivity of the backfill salt surrounding the waste canisters. Heat pipe formation depends on temperature, moisture availability, and mobility. In certain cases, dehydration of hydrous minerals provides sufficient extra moisture to push the system into a sustained heat pipe, where simulations neglecting this process do not.

  3. Dependable Hydrogen and Industrial Heat Generation from the Next Generation Nuclear Plant

    SciTech Connect

    Charles V. Park; Michael W. Patterson; Vincent C. Maio; Piyush Sabharwall

    2009-03-01

    The Department of Energy is working with industry to develop a next generation, high-temperature gas-cooled nuclear reactor (HTGR) as a part of the effort to supply the US with abundant, clean and secure energy. The Next Generation Nuclear Plant (NGNP) project, led by the Idaho National Laboratory, will demonstrate the ability of the HTGR to generate hydrogen, electricity, and high-quality process heat for a wide range of industrial applications. Substituting HTGR power for traditional fossil fuel resources reduces the cost and supply vulnerability of natural gas and oil, and reduces or eliminates greenhouse gas emissions. As authorized by the Energy Policy Act of 2005, industry leaders are developing designs for the construction of a commercial prototype producing up to 600 MWt of power by 2021. This paper describes a variety of critical applications that are appropriate for the HTGR with an emphasis placed on applications requiring a clean and reliable source of hydrogen. An overview of the NGNP project status and its significant technology development efforts are also presented.

  4. Alternative biomass sources for thermal energy generation

    NASA Astrophysics Data System (ADS)

    Steensen, Torge; Müller, Sönke; Dresen, Boris; Büscher, Olaf

    2015-04-01

    Traditionally, renewable biomass energy sources comprise forests, agriculture and other large vegetation units. With the increasing demand on those landscape elements, including conflicts of interest to nature conservation and food production, the research focus should also incorporate smaller vegetation entities. In this study, we highlight the availability of small-scale features like roadside vegetation or hedges, which are rarely featured in maps. Roadside vegetation, however, is well known and regularly trimmed to allow the passing of traffic but the cut material is rarely harvested. Here, we combine a remote-sensing-based approach to quantify the seasonal biomass harvests with a GIS-based method to outline optimal transportation routes to, and the location of, storage units and power plants. Our main data source will be ESA's upcoming Sentinel-2 optical satellite. Spatial resolution of 10 meters in the visible and near infrared requires the use of spectral unmixing to derive end member spectra of the targeted biomass objects. Additional stereo-matching and LIDAR measurements allow the accompanying height estimate to derive the biomass volume and its changes over time. GIS data bases from the target areas allow the discrimination between traditional, large features (e.g. forests and agriculture) as well as previously unaccounted for, smaller vegetation units. With the mapped biomass occurrence and additional, GIS-based infrastructure information, we can outline transport routes that take into account local restrictions like nature reserve areas, height or weight limitations as well as transport costs in relation to potential gains. This information can then be processed to outline optimal places for power plants. To simulate the upcoming Sentinel-2 data sets, we use airborne data from the AISA Eagle, spatially and spectrally down-sampled to match Sentinel 2's resolution. Our test scenario is an area in western Germany, the Kirchheller Heide, close to the city

  5. Development of the 3rd Generation ECR ion source

    SciTech Connect

    Lyneis, C.M.; Xie, Z.Q.; Taylor, C.E.

    1997-09-01

    The LBNL 3rd Generation ECR ion source has progressed from a concept to the fabrication of a full scale prototype superconducting magnet structure. This new ECR ion source will combine the recent ECR ion source techniques that significantly enhance the production of high charge state ions. The design includes a plasma chamber made from aluminum to provide additional cold electrons, three separate microwave feeds to allow multiple-frequency plasma heating (at 10, 14 and 18 GHz or at 6, 10 and 14 GHz) and very high magnetic mirror fields. The design calls for mirror fields of 4 T at injection and 3 T at extraction and for a radial field strength at the wall of 2.4 T. The prototype superconducting magnet structure which consists of three solenoid coils and six race track coils with iron poles forming the sextupole has been tested in a vertical dewar. After training, the sextupole magnet reached 105% of its design current with the solenoids off. With the solenoids operating at approximately 70% of their full design field, the sextuple coils operated at 95% of the design value which corresponds to a sextupole field strength at the plasma wall of more than 2.1 T.

  6. Localizing heat-generating defects using fluorescent microthermal imaging

    SciTech Connect

    Tangyunyong, P.; Liang, A.Y.; Righter, A.W.; Barton, D.L.; Soden, J.M.

    1996-10-01

    Fluorescent microthermal imaging (FMI) involves coating a sample surface with a thin fluorescent film that, upon exposure to UV light source, emits temperature-dependent fluorescence. The principle behind FMI was thoroughly reviewed at the ISTFA in 1994. In two recent publications, we identified several factors in film preparation and data processing that dramatically improved the thermal resolution and sensitivity of FMI. These factors include signal averaging, the use of base mixture films, film stabilization and film curing. These findings significantly enhance the capability of FMI as a failure analysis tool. In this paper, we show several examples that use FMI to quickly localize heat-generating defects (``hot spots``). When used with other failure analysis techniques such as focused ion beam (FIB) cross sectioning and scanning electron microscope (SEM) imaging, we demonstrate that FMI is a powerful tool to efficiently identify the root cause of failures in complex ICs. In addition to defect localization, we use a failing IC to I determine the sensitivity of FMI (i.e., the lowest power that can be detected) in an ideal situation where the defects are very localized and near the surface.

  7. Corner heating in rectangular solid oxide electrochemical cell generators

    DOEpatents

    Reichner, Philip

    1989-01-01

    Disclosed is an improvement in a solid oxide electrochemical cell generator 1 having a rectangular design with four sides that meet at corners, and containing multiplicity of electrically connected fuel cells 11, where a fuel gas is passed over one side of said cells and an oxygen containing gas is passed into said cells, and said fuel is burned to form heat, electricity, and an exhaust gas. The improvement comprises passing the exhaust gases over the multiplicity of cells 11 in such a way that more of the heat in said exhaust gases flows at the corners of the generator, such as through channels 19.

  8. Inductively generated streaming plasma ion source

    DOEpatents

    Glidden, Steven C.; Sanders, Howard D.; Greenly, John B.

    2006-07-25

    A novel pulsed, neutralized ion beam source is provided. The source uses pulsed inductive breakdown of neutral gas, and magnetic acceleration and control of the resulting plasma, to form a beam. The beam supplies ions for applications requiring excellent control of ion species, low remittance, high current density, and spatial uniformity.

  9. Heat-Transfer Enhancement by Artificially Generated Streamwise Vorticity

    NASA Astrophysics Data System (ADS)

    Ghanem, Akram; Habchi, Charbel; Lemenand, Thierry; Della Valle, Dominique; Peerhossaini, Hassan

    2012-11-01

    Vortex-induced heat transfer enhancement exploits longitudinal and transverse pressure-driven vortices through the deliberate artificial generation of large-scale vortical flow structures. Thermal-hydraulic performance, Nusselt number and friction factor are experimentally investigated in a HEV (high-efficiency vortex) mixer, which is a tubular heat exchanger and static mixer equipped with trapezoidal vortex generators. Pressure gradients are generated on the trapezoidal tab initiating a streamwise swirling motion in the form of two longitudinal counter-rotating vortex pairs (CVP). Due to the Kelvin-Helmholtz instability, the shear layer generated at the tab edges, which is a production site of turbulence kinetic energy (TKE), becomes unstable further downstream from the tabs and gives rise to periodic hairpin vortices. The aim of the study is to quantify the effects of hydrodynamics on the heat- and masstransfer phenomena accompanying such flows for comparison with the results of numerical studies and validate the high efficiency of the intensification process implementing such vortex generators. The experimental results reflect the enhancement expected from the numerical studies and confirm the high status of the HEV heat exchanger and static mixer.

  10. Regularities pertinent to heat transfer between torch gas layers and steam boiler firebox waterwalls. Part I. Geometrical and physical torch model as a source of heat radiation

    NASA Astrophysics Data System (ADS)

    Makarov, A. N.

    2014-09-01

    The progress seen in the 19th-21st centuries in the development of methods for calculating heat transfer in torch furnaces, fireboxes, and combustion chambers is analyzed. Throughout the 20th century, calculations of heat transfer were carried out based on the law for radiation from solid bodies deduced by Y. Stefan and L. Boltzmann. It is shown that the use of this law for calculating heat transfer of a torch (a gaseous source of radiation) in heating furnaces and power-generating installations leads to incorrect results. It is substantiated that there is crisis of methods for calculating heat transfer in torch furnaces and power-generating installations. Geometrical and physical torch models in the form of radiating cylindrical gas volumes as sources of heat radiation are proposed for overcoming this crisis.

  11. Characterization of Pu-238 Heat Source Granule Containment

    SciTech Connect

    Richardson, Paul Dean II; Sanchez, Joey Leo; Wall, Angelique Dinorah; Chavarria, Rene

    2015-02-11

    The Milliwatt Radioisotopic Themoelectric Generator (RTG) provides power for permissive-action links. Essentially these are nuclear batteries that convert thermal energy to electrical energy using a doped silicon-germanium thermopile. The thermal energy is provided by a heat source made of 238Pu, in the form of 238PuO2 granules. The granules are contained by 3 layers of encapsulation. A thin T-111 liner surrounds the 238PuO2 granules and protects the second layer (strength member) from exposure to the fuel granules. An outer layer of Hastalloy-C protects the T-111 from oxygen embrittlement. The T-111 strength member is considered the critical component in this 238PuO2 containment system. Any compromise in the strength member seen during destructive testing required by the RTG surveillance program is characterized. The T-111 strength member is characterized through Scanning Electron Microscopy (SEM), and Metallography. SEM is used in the Secondary Electron mode to reveal possible grain boundary deformation and/or cracking in the region of the strength member weld. Deformation and cracking uncovered by SEM are further characterized by Metallography. Metallography sections are mounted and polished, observed using optical microscopy, then documented in the form of microphotographs. SEM mat further be used to examine polished Metallography mounts to characterize elements using the SEM mode of Energy Dispersive X-ray spectroscopy (EDS).

  12. Welding isotopic heat sources for the cassini mission to Saturn

    SciTech Connect

    Franco-Ferreira, E.A.; George, T.G.

    1994-12-31

    In 1997 NASA will launch the Cassini scientific probe to the planet Saturn. Electric power for this probe will be provided by radioisotope thermoelecric generators thermally driven by general-purpose heat source modules. Each module contains four, 150-g pellets of {sup 238}PuO{sub 2}, individually encapsulated within a thin wall iridium-alloy shell. For the Galileo/Ulysses missions, assembly and welding took an average of 90 min per capsule. the work was done in a hot cell and the potential for personnel radiation exposure was not unduly high. The iridium alloy, from which the clad cups are made, contains a small amount of thorium to improve ductility and minimize grain growth. It has been shown that the thorium contributes to hot shortness which caused significant weld cracking during Galileo/Ulysses production. program requirements dictated that all operations provide high levels of process quality assurance. As a result, the welding system was configured to acquire copious amounts of digitized QA information. Early production operation of the welding systems has proven the ability to meet all program goals. For example, in the course of making approximately 60 girth welds during procedure qualification and safety impact testing, no rejectable weld defects have been found.

  13. Waste-heat steam generation is economically viable in ceramics

    SciTech Connect

    McMann, F.C.; Marshall, R.W.

    1984-03-01

    Generation of electric power by turbine-driven generators serviced by waste heat boilers is not a blue sky dream. It is time-proven technology, employing time-proven equipment-equipment that is expected to run uninterrupted in fouryear cycles. This equipment and its control are made right here in the U.S. The equipment is very simple to operate and maintain. This article describes the applications of ceramics in this industry.

  14. Heat generated during seating of dental implant fixtures.

    PubMed

    Flanagan, Dennis

    2014-04-01

    Frictional heat can be generated during seating of dental implants into a drill-prepared osteotomy. This in vitro study tested the heat generated by implant seating in dense bovine mandible ramus. A thermocouple was placed approximately 0.5 mm from the rim of the osteotomy during seating of each dental implant. Four diameters of implants were tested. The average temperature increases were 0.075°C for the 5.7-mm-diameter implant, 0.97°C for the 4.7-mm-diameter implant, 1.4°C for the 3.7-mm-diameter implant, and 8.6°C for the 2.5-mm-diameter implant. The results showed that heat was indeed generated and a small temperature rise occurred, apparently by the friction of the implant surface against the fresh-cut bone surface. Bone is a poor thermal conductor. The titanium of the implant and the steel of the handpiece are much better heat conductors. Titanium may be 70 times more heat conductive than bone. The larger diameter and displacement implant may act as a heat sink to draw away any heat produced from the friction of seating the implant at the bone-implant interface. The peak temperature duration was momentary, and not measured, but this was approximately less than 1 second. Except for the 2.5-mm-diameter implants, the temperature rises and durations were found to be below those previously deemed to be detrimental, so no clinically significant osseous damage would be expected during dental implant fixture seating of standard and large-diameter-sized implants. A 2.5-mm implant may generate detrimental heat during seating in nonvital bone, but this may be clinically insignificant in vital bone. The surface area and thermal conductivity are important factors in removing generated heat transfer at the bone-implant interface. The F value as determined by analysis of variance was 69.22, and the P value was less than .0001, demonstrating significant differences between the groups considered as a whole.

  15. Diabatic heating fields and the generation of available potential energy during FGGE

    NASA Technical Reports Server (NTRS)

    Salstein, David A.; Rosen, Richard D.; Baker, Wayman E.; Kalnay, Eugenia

    1986-01-01

    Global diabatic heating is estimated using fields of directly computed heating components, in particular those due to shortwave radiation, longwave radiation, sensible heating, and latent heating produced every 6 hours. The role of average fields of diabatic heating in the generation of available potential energy is examined. It is observed that latent heating is most significant in generating available potential energy.

  16. Modification of hot cells for general purpose heat source assembly at the Radioisotope Power Systems Facility

    NASA Astrophysics Data System (ADS)

    Carteret, B. A.

    1991-09-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble Pu-238 fueled heat sources for radioisotope thermoelectric generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  17. Modification of hot cells for general purpose heat source assembly at the radioisotope power systems facility

    NASA Astrophysics Data System (ADS)

    Carteret, Betty A.

    1992-01-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble 238Pu-fueled heat sources for Radioisotope Thermoelectric Generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  18. Surface pressure response to elevated tidal heating sources - Comparison of earth and Mars

    NASA Technical Reports Server (NTRS)

    Zurek, R. W.

    1980-01-01

    Modern atmospheric tidal theory has shown that the dominance of the terrestrial semidiurnal surface pressure oscillation, relative to its diurnal counterpart, is the result of the elevated heating source generated by solar heating of stratospheric ozone. Observations of the daily surface pressure variation at the Viking Lander 1 site on Mars reveal a similar predominance of the semidiurnal surface pressure oscillation only during the onset of a Martian great dust storm. Application of a classical, analytic tidal model to the Viking Lander 1 data indicates that elevating the effective heat source due to solar heating of airborne dust by a few kilometers during the onset of a Martian great dust storm can account for the observed semidiurnal surface pressure variation.

  19. Experimental evidence that potassium is a substantial radioactive heat source in planetary cores.

    PubMed

    Murthy, V Rama; van Westrenen, Wim; Fei, Yingwei

    2003-05-01

    The hypothesis that (40)K may be a significant radioactive heat source in the Earth's core was proposed on theoretical grounds over three decades ago, but experiments have provided only ambiguous and contradictory evidence for the solubility of potassium in iron-rich alloys. The existence of such radioactive heat in the core would have important implications for our understanding of the thermal evolution of the Earth and global processes such as the generation of the geomagnetic field, the core-mantle boundary heat flux and the time of formation of the inner core. Here we provide experimental evidence to show that the ambiguous results obtained from earlier experiments are probably due to previously unrecognized experimental and analytical difficulties. The high-pressure, high-temperature data presented here show conclusively that potassium enters iron sulphide melts in a strongly temperature-dependent fashion and that (40)K can serve as a substantial heat source in the cores of the Earth and Mars.

  20. Role of Internal Heat Source for Eruptive Plumes on Triton

    NASA Technical Reports Server (NTRS)

    Duxbury, N. S.; Brown, R. H.

    1996-01-01

    For the first time the role of the internal heat source, due to radioactive decay in Triton's core, is investigate with respect to geyser-like plumes...A new mechanism of energy supply to the Tritonian eruptive plumes is proposed...We present the critical values of these parameters for Triton. A possible origin of the subsurface vents on Triton is also suggested.

  1. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    SciTech Connect

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  2. Analytical calculation of the skin temperature distribution due to subcutaneous heat production in a spherical heat source.

    PubMed

    Gustafsson, S E; Nilsson, S K; Torell, L M

    1975-03-01

    An analytical solution of the thermal conductivity equation describing the surface temperature distribution over a buried heat source is given in tabular form. The solution is applicable to experimental models for studies of the surface temperature over an implanted artificial heat source. The results can also be used for the analysis of the skin temperature over biological heat sources such as breat tumours.

  3. Variable Conductance Heat Pipe Cooling of Stirling Convertor and General Purpose Heat Source

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Schwendeman, Carl; Anderson, William G.; Cornell, Peggy A.; Schifer, Nicholas A.

    2013-01-01

    In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

  4. Internal heating of lithium-ion batteries using alternating current based on the heat generation model in frequency domain

    NASA Astrophysics Data System (ADS)

    Zhang, Jianbo; Ge, Hao; Li, Zhe; Ding, Zhanming

    2015-01-01

    This study develops a method to internally preheat lithium-ion batteries at low temperatures with sinusoidal alternating current (AC). A heat generation rate model in frequency domain is developed based on the equivalent electrical circuit. Using this model as the source term, a lumped energy conservation model is adopted to predict the temperature rise. These models are validated against the experimental results of preheating an 18650 cell at different thermal insulation conditions. The effects of current amplitude and frequency on the heating rate are illustrated with a series of simulated contours of heating time. These contours indicate that the heating rate increases with higher amplitude, lower frequency and better thermal insulation. The cell subjected to an alternating current with an amplitude of 7 A (2.25 C) and a frequency of 1 Hz, under a calibrated heat transfer coefficient of 15.9 W m-2 K-1, can be heated from -20 °C to 5 °C within 15 min and the temperature distribution remains essentially uniform. No capacity loss is found after repeated AC preheating tests, indicating this method incurs little damage to the battery health. These models are computationally-efficient and can be used in real time to control the preheating devices in electric vehicles.

  5. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources. (a) The aggregate capacity of the electric ship's service generating sources required in § 111.10-3...

  6. 46 CFR 111.10-3 - Two generating sources.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....

  7. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources. (a) The aggregate capacity of the electric ship's service generating sources required in § 111.10-3...

  8. 46 CFR 111.10-3 - Two generating sources.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....

  9. 46 CFR 111.10-3 - Two generating sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....

  10. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources. (a) The aggregate capacity of the electric ship's service generating sources required in § 111.10-3...

  11. 46 CFR 111.10-4 - Power requirements, generating sources.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 111.10-4 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-4 Power requirements, generating sources. (a) The aggregate capacity of the electric ship's service generating sources required in § 111.10-3...

  12. 46 CFR 111.10-3 - Two generating sources.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS... drilling unit must have at least two electric generating sources....

  13. 46 CFR 111.10-3 - Two generating sources.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Two generating sources. 111.10-3 Section 111.10-3 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Power Supply § 111.10-3 Two generating sources. In addition to the emergency...

  14. Drilling in bone: modeling heat generation and temperature distribution.

    PubMed

    Davidson, Sean R; James, David F

    2003-06-01

    Thermo-mechanical equations were developed from machining theory to predict heat generation due to drilling and were coupled with a heat transfer FEM simulation to predict the temperature rise and thermal injury in bone during a drilling operation. The rotational speed, feed rate, drill geometry and bone material properties were varied in a parametric analysis to determine the importance of each on temperature rise and therefore on thermal damage. It was found that drill speed, feed rate and drill diameter had the most significant thermal impact while changes in drill helix angle, point angle and bone thermal properties had relatively little effect.

  15. Heat generation in aircraft tires under free rolling conditions

    NASA Technical Reports Server (NTRS)

    Clark, S. K.; Dodge, R. N.

    1982-01-01

    A method was developed for calculating the internal temperature distribution in an aircraft tire while free rolling under load. The method uses an approximate stress analysis of each point in the tire as it rolls through the contact patch, and from this stress change the mechanical work done on each volume element may be obtained and converted into a heat release rate through a knowledge of material characteristics. The tire cross-section is then considered as a body with internal heat generation, and the diffusion equation is solved numerically with appropriate boundary conditions of the wheel and runway surface. Comparison with data obtained with buried thermocouples in tires shows good agreement.

  16. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    SciTech Connect

    Mittereder, N.; Poerschke, A.

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.

  17. Parametric Optimization of Thermoelectric Generators for Waste Heat Recovery

    NASA Astrophysics Data System (ADS)

    Huang, Shouyuan; Xu, Xianfan

    2016-06-01

    This paper presents a methodology for design optimization of thermoelectric-based waste heat recovery systems called thermoelectric generators (TEGs). The aim is to maximize the power output from thermoelectrics which are used as add-on modules to an existing gas-phase heat exchanger, without negative impacts, e.g., maintaining a minimum heat dissipation rate from the hot side. A numerical model is proposed for TEG coupled heat transfer and electrical power output. This finite-volume-based model simulates different types of heat exchangers, i.e., counter-flow and cross-flow, for TEGs. Multiple-filled skutterudites and bismuth-telluride-based thermoelectric modules (TEMs) are applied, respectively, in higher and lower temperature regions. The response surface methodology is implemented to determine the optimized TEG size along and across the flow direction and the height of thermoelectric couple legs, and to analyze their covariance and relative sensitivity. A genetic algorithm is employed to verify the globality of the optimum. The presented method will be generally useful for optimizing heat-exchanger-based TEG performance.

  18. Parametric Optimization of Thermoelectric Generators for Waste Heat Recovery

    NASA Astrophysics Data System (ADS)

    Huang, Shouyuan; Xu, Xianfan

    2016-10-01

    This paper presents a methodology for design optimization of thermoelectric-based waste heat recovery systems called thermoelectric generators (TEGs). The aim is to maximize the power output from thermoelectrics which are used as add-on modules to an existing gas-phase heat exchanger, without negative impacts, e.g., maintaining a minimum heat dissipation rate from the hot side. A numerical model is proposed for TEG coupled heat transfer and electrical power output. This finite-volume-based model simulates different types of heat exchangers, i.e., counter-flow and cross-flow, for TEGs. Multiple-filled skutterudites and bismuth-telluride-based thermoelectric modules (TEMs) are applied, respectively, in higher and lower temperature regions. The response surface methodology is implemented to determine the optimized TEG size along and across the flow direction and the height of thermoelectric couple legs, and to analyze their covariance and relative sensitivity. A genetic algorithm is employed to verify the globality of the optimum. The presented method will be generally useful for optimizing heat-exchanger-based TEG performance.

  19. Increased use of reject heat from electric generation

    SciTech Connect

    Leigh, R.W.; Piraino, M.

    1994-02-01

    This study aims to determine existing barriers to greater use of reject heat by electric power producers, including utilities and cogenerators. It includes analytical studies of the technical and economic issues and a survey of several electric power producers. The core analytic findings of the study are that although electric utility- based, cogenerated district heating is sometimes cost competitive with currently common furnaces and boilers, it is not clearly less expensive, and is often more expensive. Since market penetration by a new technology depends on strong perceived advantages, district heating will remain at a disadvantage unless its benefits, such as lowered emissions and decreased reliance on foreign oil, are given overt financial form through subsidies or tax incentives. The central finding from the survey was that electric utilities have arrived at the same conclusion by their own routes; we present a substantial list of their reasons for not engaging in district heating or for not pursuing it more vigorously, and many of them can be summarized as the lack of a clear cost advantage for district heat. We also note that small-scale district heating systems, based on diesel generators and located near the thermal load center, show very clear cost advantages over individual furnaces. This cost advantage is consistent with the explosive growth currently observed in private cogeneration systems.

  20. Self-Heating Effects In Polysilicon Source Gated Transistors

    PubMed Central

    Sporea, R. A.; Burridge, T.; Silva, S. R. P.

    2015-01-01

    Source-gated transistors (SGTs) are thin-film devices which rely on a potential barrier at the source to achieve high gain, tolerance to fabrication variability, and low series voltage drop, relevant to a multitude of energy-efficient, large-area, cost effective applications. The current through the reverse-biased source barrier has a potentially high positive temperature coefficient, which may lead to undesirable thermal runaway effects and even device failure through self-heating. Using numerical simulations we show that, even in highly thermally-confined scenarios and at high current levels, self-heating is insufficient to compromise device integrity. Performance is minimally affected through a modest increase in output conductance, which may limit the maximum attainable gain. Measurements on polysilicon devices confirm the simulated results, with even smaller penalties in performance, largely due to improved heat dissipation through metal contacts. We conclude that SGTs can be reliably used for high gain, power efficient analog and digital circuits without significant performance impact due to self-heating. This further demonstrates the robustness of SGTs. PMID:26351099

  1. Self-Heating Effects In Polysilicon Source Gated Transistors.

    PubMed

    Sporea, R A; Burridge, T; Silva, S R P

    2015-09-09

    Source-gated transistors (SGTs) are thin-film devices which rely on a potential barrier at the source to achieve high gain, tolerance to fabrication variability, and low series voltage drop, relevant to a multitude of energy-efficient, large-area, cost effective applications. The current through the reverse-biased source barrier has a potentially high positive temperature coefficient, which may lead to undesirable thermal runaway effects and even device failure through self-heating. Using numerical simulations we show that, even in highly thermally-confined scenarios and at high current levels, self-heating is insufficient to compromise device integrity. Performance is minimally affected through a modest increase in output conductance, which may limit the maximum attainable gain. Measurements on polysilicon devices confirm the simulated results, with even smaller penalties in performance, largely due to improved heat dissipation through metal contacts. We conclude that SGTs can be reliably used for high gain, power efficient analog and digital circuits without significant performance impact due to self-heating. This further demonstrates the robustness of SGTs.

  2. Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

    SciTech Connect

    Mittereder, Nick; Poerschke, Andrew

    2013-11-01

    This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHP in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season.

  3. Assessment of next generation nuclear plant intermediate heat exchanger design.

    SciTech Connect

    Majumdar, S.; Moisseytsev, A.; Natesan, K.; Nuclear Engineering Division

    2008-10-17

    The Next Generation Nuclear Plant (NGNP), which is an advanced high temperature gas reactor (HTGR) concept with emphasis on production of both electricity and hydrogen, involves helium as the coolant and a closed-cycle gas turbine for power generation with a core outlet/gas turbine inlet temperature of 900-1000 C. In the indirect cycle system, an intermediate heat exchanger is used to transfer the heat from primary helium from the core to the secondary fluid, which can be helium, nitrogen/helium mixture, or a molten salt. The system concept for the vary high temperature reactor (VHTR) can be a reactor based on the prismatic block of the GT-MHR developed by a consortium led by General Atomics in the U.S. or based on the PBMR design developed by ESKOM of South Africa and British Nuclear Fuels of U.K. This report has made an assessment on the issues pertaining to the intermediate heat exchanger (IHX) for the NGNP. A detailed thermal hydraulic analysis, using models developed at ANL, was performed to calculate heat transfer, temperature distribution, and pressure drop. Two IHX designs namely, shell and straight tube and compact heat exchangers were considered in an earlier assessment. Helical coil heat exchangers were analyzed in the current report and the results were compared with the performance features of designs from industry. In addition, a comparative analysis is presented between the shell and straight tube, helical, and printed circuit heat exchangers from the standpoint of heat exchanger volume, primary and secondary sides pressure drop, and number of tubes. The IHX being a high temperature component, probably needs to be designed using ASME Code Section III, Subsection NH, assuming that the IHX will be classified as a class 1 component. With input from thermal hydraulic calculations performed at ANL, thermal conduction and stress analyses were performed for the helical heat exchanger design and the results were compared with earlier-developed results on

  4. Numerical analysis of heat exchange processes for the ground source heat pump system

    NASA Astrophysics Data System (ADS)

    Saito, H.; Muto, H.; Moritani, S.; Kohgo, Y.; Hamamoto, S.; Takemura, T.; Ohnishi, J.; Komatsu, T.

    2012-12-01

    Ground source heat pump systems (GSHP) use ground or groundwater as a heat source. They can achieve much higher coefficient of performance (COP) than conventional air source heat pump systems because the temperature of the ground is much more stable than that of the air. Heat energy in the ground is then viewed as one of the renewable energy sources. GSHP has been receiving great interests among countries in North America and Western Europe, as well as some developed countries in Asia because it can potentially reduce energy consumption and greenhouse gas emission. While GSHP can inject heat from the buildings to the ground for cooling during the summer, it can pump heat stored in the ground for heating during the winter. As some physical, chemical, and biological properties of the ground and groundwater are temperature dependent, running GSHP can eventually affect groundwater quality. The main objective of this project was to develop a model that allows predicting not only ground and groundwater temperatures but also changes in physical, chemical, and biological properties of ground and groundwater with GSHP under operations. This particular study aims at simulating heat exchange and transfer processes in the ground for a vertical-loop closed GSHP system. In the closed GSHP system, an anti-freezing solution is circulated inside the closed-loop tube, called U-tube, that is buried in the ground. Heat is then transferred to the anti-freezing solution in the U-tube by a heat exchanger. In this study we used HYDRUS to predict temperature of the anti-freezing solution, as well as that of the ground. HYDRUS allows one to simulate variably-saturated water flow and solute and heat transport in porous media numerically in two- and three-dimensional domains with great flexibility in defining boundary conditions. At first changes in anti-freezing solution temperatures measured were predicted in response to Thermal Response Test (TRT) conducted at our study site. Then, heat

  5. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, D.G.

    1993-03-30

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  6. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, David G.

    1993-01-01

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  7. High electric field deuterium ion sources for neutron generators

    NASA Astrophysics Data System (ADS)

    Reichenbach, Birk

    Active interrogation systems for highly enriched uranium require improved fieldable neutron sources. The target technology for deuterium-tritium neutron generators is well understood and the most significant improvement can be achieved by improving the deuterium ion source through increased output and, in some cases, lifetime of the ion source. We are developing a new approach to a deuterium ion sources based upon the field desorption/evaporation of deuterium from the surfaces of metal tips. Electrostatic field desorption (EFD) desorbs previously adsorbed deuterium as ions under the influence of high electric fields (several V/A), without removing tip material. Single etched wire tip experiments have been performed and have shown that this is difficult but can be achieved with molybdenum and tungsten tips. Electrostatic field evaporation (EFE) evaporates ultra thin deuterated titanium films as ions. It has been shown that several 10s of atomic layers can be removed within a few nanoseconds from etched tungsten tips. In the course of these studies titanium deposition and deuteration methods were studied and new detection methods developed. Space charge effects resulting from the large ion currents were identified to be the most likely cause of some unusual ion emission characteristics. In addition, on W < 110 > oriented substrates a surprising body-centered cubic crystal structure of the titanium film was found and studied. The ion currents required for neutron generator applications can be achieved by microfabrication of metal tip arrays. Field desorption studies of microfabricated field emitter tip arrays have been conducted for the first time. Maximum fields of 3 V/A have been applied to the array tip surfaces to date, although fields of ˜ 2 V/A to ˜ 2.5 V/A are more typical. Desorption of atomic deuterium ions has been observed at fields of roughly 2 V/A at room temperature. The desorption of common surface adsorbates, such as hydrogen, carbon, water, and

  8. Turbulence generation through intense kinetic energy sources

    NASA Astrophysics Data System (ADS)

    Maqui, Agustin F.; Donzis, Diego A.

    2016-06-01

    Direct numerical simulations (DNS) are used to systematically study the development and establishment of turbulence when the flow is initialized with concentrated regions of intense kinetic energy. This resembles both active and passive grids which have been extensively used to generate and study turbulence in laboratories at different Reynolds numbers and with different characteristics, such as the degree of isotropy and homogeneity. A large DNS database was generated covering a wide range of initial conditions with a focus on perturbations with some directional preference, a condition found in active jet grids and passive grids passed through a contraction as well as a new type of active grid inspired by the experimental use of lasers to photo-excite the molecules that comprise the fluid. The DNS database is used to assert under what conditions the flow becomes turbulent and if so, the time required for this to occur. We identify a natural time scale of the problem which indicates the onset of turbulence and a single Reynolds number based exclusively on initial conditions which controls the evolution of the flow. It is found that a minimum Reynolds number is needed for the flow to evolve towards fully developed turbulence. An extensive analysis of single and two point statistics, velocity as well as spectral dynamics and anisotropy measures is presented to characterize the evolution of the flow towards realistic turbulence.

  9. Light source heat absorption analysis of a Dyson type lithography lens

    NASA Astrophysics Data System (ADS)

    Hsu, Ming-Ying; Ho, Cheng-Fang; Chang, Shenq-Tsong; Huang, Ting-Ming

    2015-09-01

    The lithography system in a high energy light source, the system refractive lens, absorbs the heat from the light source. The light source's power is uniformly distributed on the reticle side. The incident rays' power density is calculated by radiometry in each lens' surface. The lens heat absorption ratio depends on the optical glass species, quality, and wavelength. The optical glass' higher internal transmittance means less heat absorption; meanwhile, in different conditions, the lens' refractive index will change with temperature. Other researchers have tried to calculate the lens temperature distribution; this study applies the Finite Element Method (FEM), radiometry, and ray tracing to solve the lens temperature distribution. Each incident ray's path was separated into many sections, and the heat absorption was calculated for each section. Therefore, the heat generated in incident ray sections were weighted to finite element grids and the temperature distribution was solved. The lens' non uniform temperature distribution will cause the incident ray's Optical Path Difference (OPD). Each incident ray's OPD can be fit by Zernike polynomials; the fitting results can be input into optical software to evaluate the thermal effect on lens heat absorption.

  10. Miniature, low-power X-ray tube using a microchannel electron generator electron source

    NASA Technical Reports Server (NTRS)

    Elam, Wm. Timothy (Inventor); Kelliher, Warren C. (Inventor); Hershyn, William (Inventor); DeLong, David P. (Inventor)

    2011-01-01

    Embodiments of the invention provide a novel, low-power X-ray tube and X-ray generating system. Embodiments of the invention use a multichannel electron generator as the electron source, thereby increasing reliability and decreasing power consumption of the X-ray tube. Unlike tubes using a conventional filament that must be heated by a current power source, embodiments of the invention require only a voltage power source, use very little current, and have no cooling requirements. The microchannel electron generator comprises one or more microchannel plates (MCPs), Each MCP comprises a honeycomb assembly of a plurality of annular components, which may be stacked to increase electron intensity. The multichannel electron generator used enables directional control of electron flow. In addition, the multichannel electron generator used is more robust than conventional filaments, making the resulting X-ray tube very shock and vibration resistant.

  11. The impact of municipal waste combustion in small heat sources

    NASA Astrophysics Data System (ADS)

    Vantúch, Martin; Kaduchová, Katarína; Lenhard, Richard

    2016-06-01

    At present there is a tendency to make greater use for heating houses for burning solid fuel, such as pieces of wood, coal, coke, local sources of heat to burn natural gas. This tendency is given both the high price of natural gas as well as the availability of cheaper solid fuel. In many cases, in the context saving heating costs, respectively in the context of the disposal of waste is co-incinerated with municipal solid fuels and wastes of different composition. This co entails increased production emissions such as CO (carbon monoxide), NOx (nitrogen oxides), particulate matter (particulate matter), PM10, HCl (hydrogen chloride), PCDD/F (polychlorinated dibenzodioxins and dibenzofurans), PCBs (polychlorinated biphenyls) and others. The experiment was focused on the emission factors from the combustion of fossil fuels in combination with municipal waste in conventional boilers designed to burn solid fuel.

  12. Car companies look to generate power from waste heat

    NASA Astrophysics Data System (ADS)

    Schirber, Michael

    2008-04-01

    You might think that the steam engine is an outdated technology that had its heyday centuries ago, but in fact steam is once again a hot topic with vehicle manufacturers. Indeed, the next generation of hybrid cars and trucks may incorporate some form of steam power. Honda, for example, has just released details of a new prototype hybrid car that recharges its battery using a steam engine that exploits waste heat from the exhaust pipe.

  13. Microwave heating for the rapid generation of glycosylhydrazides.

    PubMed

    Mallevre, F; Roget, A; Minon, T; Kervella, Y; Ropartz, D; Ralet, M C; Canut, H; Livache, T

    2013-07-17

    Conditions for simple derivatization of reducing carbohydrates via adipic acid dihydrazide microwave-assisted condensation are described. We demonstrate with a diverse set of oligo- and polysaccharides how to improve a restrictive and labor intensive conventional conjugation protocol by using microwave-assisted chemistry. We show that 5 min of microwave heating in basic or acidic conditions are adequate to generate, in increased yields, intact and functional glycosylhydrazides, whereas hours to days and acidic conditions are generally required under conventional methods. PMID:23731134

  14. Sound generated by vortex ring impingement on a heated wall

    NASA Astrophysics Data System (ADS)

    Kotsari, E. Giannos; Howe, M. S.

    2009-11-01

    An analysis is made of the sound generated when a vortex ring impinges normally on a heated section of a plane wall. The unsteady convective diffusion occurring when the vortex is close to the wall causes a rapid increase in heat transfer and the emission of sound of monopole type. The approximate dependence on vortex Reynolds number of the enhancement of heat transfer is deduced from recent experiments reported by Arévalo et al. [Vortex ring head-on collision with a heated vertical plate, Physics of Fluids 19 (2007) 083603-1-083603-9], and is used to derive a scaling law for the acoustic pressure. The sound pressure signature is dominated by a large amplitude pulse associated with an explosive, but brief increase in the rate of heat transfer at the start of the vortex-wall interaction. The quadrupole sound pressure also produced during impingement on the wall is found to be smaller than the thermally induced sound by a factor proportional to M2T0/(Tw-T0) where M, Tw, T0 respectively denote the Mach number of the vortex motion, the mean wall temperature and the fluid temperature at large distances from the wall.

  15. Thermoelectric Generation Using Waste Heat in Steel Works

    NASA Astrophysics Data System (ADS)

    Kuroki, Takashi; Kabeya, Kazuhisa; Makino, Kazuya; Kajihara, Takeshi; Kaibe, Hiromasa; Hachiuma, Hirokuni; Matsuno, Hidetoshi; Fujibayashi, Akio

    2014-06-01

    The steelmaking industry in Japan has significantly reduced its energy use for the past several decades and has kept the highest energy efficiency in the world. However, the steelmaking industry is strongly required to develop new technologies for further energy conservation in view of energy security, high and volatile energy prices, and climate change. One of the key technologies to achieve the requirement is waste heat recovery. This paper describes the thermoelectric generation (TEG) system using the waste heat in the steelmaking process. In this system, the TEG unit, which consists of 16 thermoelectric modules made of Bi-Te thermoelectric materials, generates the electrical power directly by converting the radiant heat released from hot steel products. Each thermoelectric module, whose size is 50 mm × 50 mm × 4.2 mm, generates 18 W when the hot-side temperature is 523 K and the cold-side is 303 K. Therefore, the output of the TEG unit is over 250 W. The performance and the durability of the system have been investigated under various operating conditions in steel works. The results of the verification tests in the JFE steel Corporation's continuous casting line will be discussed.

  16. Soft electrons as a possible heat source for Jupiter's thermosphere

    NASA Technical Reports Server (NTRS)

    Hunten, D. M.; Dessler, A. J.

    1977-01-01

    The 850 K exospheric temperature inferred for Jupiter from the radio-occultation experiments on Pioneers 10 and 11 is shown to imply a heat input of 0.25-0.5 erg/sq cm/sec. One possible source of this energy is precipitation of electrons from a warm plasma (temperature corresponding to energies of the order of 30-500 eV). A mechanism is suggested wherein the presence of this plasma can be accounted for by centrifugal acceleration and adiabatic compression of ionospheric electrons and protons. Present ideas of the source strength of ionospheric plasma, however, give heating rates that are too small by one to two orders of magnitude, although inferences from direct plasma measurements suggest that the required plasma is indeed present.

  17. North Village Ground Source Heat Pump Demonstration Project

    SciTech Connect

    Redderson, Jeff

    2015-08-03

    This project demonstrated the feasibility of converting from a traditional direct exchange system to a ground source heat pump system on a large scale, multiple building apartment complex on a university campus. A total of ten apartment buildings were converted using vertical well fields and a ground source loop that connected the 24 apartments in each building into a common system. The system has yielded significant operational savings in both energy and maintenance and transformed the living environments of these residential buildings for our students.

  18. Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results

    SciTech Connect

    O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

    2002-08-01

    A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

  19. The 4th Generation Light Source at Jefferson Lab

    SciTech Connect

    Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Albert Grippo; Christopher Gould; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; John Klopf; Steven Moore; George Neil; Thomas Powers; Joseph Preble; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-04-25

    A number of "Grand Challenges" in Science have recently been identified in reports from The National Academy of Sciences, and the U.S. Dept. of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab. Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources.

  20. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    SciTech Connect

    George, T.G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of /sup 238/Pu ..cap alpha..-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs.

  1. General-purpose heat source safety verification test series: SVT-7 through SVT-10

    NASA Astrophysics Data System (ADS)

    George, T. G.; Pavone, D.

    1985-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of (238)PuO2 (ALPHA)-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15(0) and 30(0).

  2. General-Purpose Heat Source Safety Verification Test series: SVT-7 through SVT-10

    SciTech Connect

    George, T.G.; Pavone, D.

    1985-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of /sup 238/PuO/sub 2/ ..cap alpha..-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15/sup 0/ and 30/sup 0/.

  3. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    NASA Astrophysics Data System (ADS)

    George, T. G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of Pu -decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs.

  4. Nanofluid flow and forced convection heat transfer over a stretching surface considering heat source

    NASA Astrophysics Data System (ADS)

    Mohammadpour, M.; Valipour, P.; Shambooli, M.; Ayani, M.; Mirparizi, M.

    2015-07-01

    In this paper, magnetic field effects on the forced convection flow of a nanofluid over a stretching surface in the presence of heat generation/absorption are studied. The equations of continuity, momentum and energy are transformed into ordinary differential equations and solved numerically using the fourth-order Runge-Kutta integration scheme featuring the shooting technique. Different types of nanoparticles as copper (Cu), silver (Ag), alumina (Al2O3) and titania (TiO2) with water as their base fluid has been considered. The influence of significant parameters, such as magnetic parameter, volume fraction of the nanoparticles, heat generation/absorption parameter, velocity ratio parameter and temperature index parameter on the flow and heat transfer characteristics are discussed. The results show that the values of temperature profiles increase with increasing heat generation/absorption and volume fraction of the nanoparticles but they decrease with increasing velocity ratio parameter and temperature index parameter. Also, it can be found that selecting silver as nanoparticle leads to the highest heat transfer enhancement.

  5. Engineering Scoping Study of Thermoelectric Generator Systems for Industrial Waste Heat Recovery

    SciTech Connect

    Hendricks, Terry; Choate, William T.

    2006-11-01

    This report evaluates thermoelectric generator (TEG) systems with the intent to: 1) examine industrial processes in order to identify and quantify industrial waste heat sources that could potentially use TEGs; 2) describe the operating environment that a TEG would encounter in selected industrial processes and quantify the anticipated TEG system performance; 3) identify cost, design and/or engineering performance requirements that will be needed for TEGs to operate in the selected industrial processes; and 4) identify the research, development and deployment needed to overcome the limitations that discourage the development and use of TEGs for recovery of industrial waste heat.

  6. Thermoelectric energy converter for generation of electricity from low-grade heat

    DOEpatents

    Jayadev, T.S.; Benson, D.K.

    1980-05-27

    A thermoelectric energy conversion device which includes a plurality of thermoelectric elements is described. A hot liquid is supplied to one side of each element and a cold liquid is supplied to the other side of each element. The thermoelectric generator may be utilized to produce power from low-grade heat sources such as ocean thermal gradients, solar ponds, and low-grade geothermal resources. (WHK)

  7. Heat exchanger sizing for vertical closed-loop ground-source heat pumps

    SciTech Connect

    Cane, R.L.D.; Clemes, S.B.; Morrison, A.; Hughes, P.J.

    1995-12-31

    A building energy simulation program has been used in conjunction with a ground heat exchanger sizing algorithm to develop general guidelines on how to size vertical ground heat exchangers for closed-loop ground-source heat pump systems in large buildings. The analysis considered three commercial building types of varying size with different internal loads and heat pump efficiencies. Each building variation was simulated in seven cities, three in the US and four in Canada. The ground heat exchanger sizing algorithm has been previously validated against actual system data. The analysis results showed a strong correlation between heat exchanger length required and annual energy rejected to the ground, if the building was cooling-dominated, or annual energy extracted from the ground, if the building was heating-dominated. The resulting sizing guidelines recommend hour-by-hour energy analysis to determine the energy extracted from and rejected to the building water loop. Using this information the designer will have available easy-to-use, accurate sizing guidelines that should result in more economical installations than those based on previous ``rule of thumb`` guidelines.

  8. Dynamics of density cavities generated by frictional heating: Formation, distortion, and instability

    NASA Astrophysics Data System (ADS)

    Zettergren, M. D.; Semeter, J. L.; Dahlgren, H.

    2015-12-01

    A simulation study of the generation and evolution of mesoscale density cavities in the polar ionosphere is conducted using a time-dependent, nonlinear, quasi-electrostatic model. The model demonstrates that density cavities, generated by frictional heating, can form in as little as 90 s due to strong electric fields of ˜120 mV/m, which are sometimes observed near auroral zone and polar cap arcs. Asymmetric density cavity features and strong plasma density gradients perpendicular to the geomagnetic field are naturally generated as a consequence of the strong convection and finite extent of the auroral feature. The walls of the auroral density cavities are shown to be susceptible to large-scale distortion and gradient-drift instability, hence indicating that arc-related regions of frictional heating may be a source of polar ionospheric density irregularities.

  9. BEM solution to transient free convective heat transfer in a viscous, electrically conducting, and heat generating fluid

    SciTech Connect

    Vajravelu, K.; Kassab, A.; Hadjinicolaou, A.

    1996-11-08

    The nonlinear partial differential equations for the transient free convective heat transfer in a viscous, electrically conducting, and heat-generating fluid past a vertical porous plate in the presence of free stream oscillations are solved by the boundary element method (BEM). Time-dependent fundamental solutions are employed in a time marching scheme to resolve the field variables. Numerical results are compared with previously reported analytical solutions in order to validate the developed BEM algorithm. These previous studies reported results for simpler versions of the problem, in which the convective effects in the momentum and energy equations were neglected in order to obtain analytical numerical solutions. The BEM results are shown to be in close agreement with the reported data. The effects of convection currents, the temperature-dependent heat sources (or sinks), the magnetic currents, and the viscous dissipation on the flow and heat transfer characteristics are assessed in a parametric study, which considers a variety of the dimensionless parameters Gr, Ec, Pr, M, and {gamma}. It is observed that {gamma} plays an important role in delaying the fluid flow reversal, present in the case of air, and acts to enhance the effect of Gr in augmenting the rate of heat transfer at the wall. The skin friction is observed to be an increasing function of Gr, Ec, and {gamma} and a decreasing function of M and Pr. However, the rate of heat transfer (in an absolute sense) is an increasing function of M, {gamma}, Gr, and Ec and a decreasing function of Pr. Of all the parameters, the Prandtl number has the strongest effect on the flow and heat transfer characteristics.

  10. A power conditioning system for radioisotope thermoelectric generator energy sources

    NASA Technical Reports Server (NTRS)

    Gillis, J. A., Jr.

    1974-01-01

    The use of radioisotope thermoelectric generators (RTG) as the primary source of energy in unmanned spacecraft is discussed. RTG output control, power conditioning system requirements, the electrical design, and circuit performance are also discussed.

  11. Heated birthing pools as a source of Legionnaires' disease.

    PubMed

    Collins, S L; Afshar, B; Walker, J T; Aird, H; Naik, F; Parry-Ford, F; Phin, N; Harrison, T G; Chalker, V J; Sorrell, S; Cresswell, T

    2016-03-01

    In June 2014 Public Health England confirmed a case of Legionnaires' disease (LD) in a neonate following birth at home in a hired birthing pool incorporating a heater and a recirculation pump which had been filled in advance of labour. The case triggered a public health investigation and a microbiological survey of an additional ten heated birthing pools hired or recently hired to the general public across England. The birthing pool used by the parent of the confirmed case was identified as the source of the neonate's infection following detection of Legionella pneumophila ST48 in both patient and environmental samples. Legionella species were detected by quantitative polymerase chain reaction but not culture in a further three pools together with other opportunistic pathogens identified by culture and matrix-assisted laser desorption ionization-time of flight (MALDI-ToF) mass spectrometry. A Patient Safety Alert from NHS England and Public Health England was issued stating that heated birthing pools filled in advance of labour should not be used for home births. This recommendation remains in place. This investigation in conjunction with other recent reports has highlighted a lack of awareness regarding the microbiological safety of heated birthing pools and their potential to be a source of LD and other opportunistic infections. Furthermore, the investigation raised important considerations with regards to microbiological sampling and testing in such incidents. Public health authorities and clinicians should consider LD in the differential diagnosis of severe respiratory infection in neonates within 14 days of a water birth. PMID:26289365

  12. Ground-source heat pump case studies and utility programs

    SciTech Connect

    Lienau, P.J.; Boyd, T.L.; Rogers, R.L.

    1995-04-01

    Ground-source heat pump systems are one of the promising new energy technologies that has shown rapid increase in usage over the past ten years in the United States. These systems offer substantial benefits to consumers and utilities in energy (kWh) and demand (kW) savings. The purpose of this study was to determine what existing monitored data was available mainly from electric utilities on heat pump performance, energy savings and demand reduction for residential, school and commercial building applications. In order to verify the performance, information was collected for 253 case studies from mainly utilities throughout the United States. The case studies were compiled into a database. The database was organized into general information, system information, ground system information, system performance, and additional information. Information was developed on the status of demand-side management of ground-source heat pump programs for about 60 electric utility and rural electric cooperatives on marketing, incentive programs, barriers to market penetration, number units installed in service area, and benefits.

  13. Nondestructive inspection of General Purpose Heat Source (GPHS) girth welds

    SciTech Connect

    Reimus, M.A.H.; George, T.G.; Lynch, C.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using iridium capsules, TIG welded, to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Since experience in the past had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of the capsule weld is required. A ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors that exceeded the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results.

  14. Heated birthing pools as a source of Legionnaires' disease.

    PubMed

    Collins, S L; Afshar, B; Walker, J T; Aird, H; Naik, F; Parry-Ford, F; Phin, N; Harrison, T G; Chalker, V J; Sorrell, S; Cresswell, T

    2016-03-01

    In June 2014 Public Health England confirmed a case of Legionnaires' disease (LD) in a neonate following birth at home in a hired birthing pool incorporating a heater and a recirculation pump which had been filled in advance of labour. The case triggered a public health investigation and a microbiological survey of an additional ten heated birthing pools hired or recently hired to the general public across England. The birthing pool used by the parent of the confirmed case was identified as the source of the neonate's infection following detection of Legionella pneumophila ST48 in both patient and environmental samples. Legionella species were detected by quantitative polymerase chain reaction but not culture in a further three pools together with other opportunistic pathogens identified by culture and matrix-assisted laser desorption ionization-time of flight (MALDI-ToF) mass spectrometry. A Patient Safety Alert from NHS England and Public Health England was issued stating that heated birthing pools filled in advance of labour should not be used for home births. This recommendation remains in place. This investigation in conjunction with other recent reports has highlighted a lack of awareness regarding the microbiological safety of heated birthing pools and their potential to be a source of LD and other opportunistic infections. Furthermore, the investigation raised important considerations with regards to microbiological sampling and testing in such incidents. Public health authorities and clinicians should consider LD in the differential diagnosis of severe respiratory infection in neonates within 14 days of a water birth.

  15. Acoustic Optimization of Automotive Exhaust Heat Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Su, C. Q.; Ye, B. Q.; Guo, X.; Hui, P.

    2012-06-01

    The potential for thermoelectric exhaust heat recovery in vehicles has been increasing with recent advances in the efficiency of thermoelectric generators (TEGs). This study analyzes the acoustic attenuation performance of exhaust-based TEGs. The acoustic characteristics of two different thermal designs of exhaust gas heat exchanger in TEGs are discussed in terms of transmission loss and acoustic insertion loss. GT-Power simulations and bench tests on a dynamometer with a high-performance production engine are carried out. Results indicate that the acoustic attenuation of TEGs could be determined and optimized. In addition, the feasibility of integration of exhaust-based TEGs and engine mufflers into the exhaust line is tested, which can help to reduce space and improve vehicle integration.

  16. High heat generation safety issue in tank 241-C-106

    SciTech Connect

    Bander, T.J., Westinghouse Hanford

    1996-07-10

    A `White` paper was written on the High Heat Generation Safety Issue in Tank 241-C-106. The issue is if tank 241-C-106 should start leaking, the lack of alternative cooling methods will require continued addition of water and thereby possibly increase the amount of leakage to the ground. If the current methods of cooling the tank are stopped, the sludge and concrete structure will heat to temperatures greater than established limits and may cause structural damage, leading to dome collapse and possibly an unacceptable radioactive release to the environment. Potential approaches to the resolution of this issue were evaluated, and waste retrieval by sluicing and transfer to a double-shell tank was selected. The paper gives background information on the tank and an assessment of the issue and its resolution, with references to support the paper.

  17. A multiple step random walk Monte Carlo method for heat conduction involving distributed heat sources

    NASA Astrophysics Data System (ADS)

    Naraghi, M. H. N.; Chung, B. T. F.

    1982-06-01

    A multiple step fixed random walk Monte Carlo method for solving heat conduction in solids with distributed internal heat sources is developed. In this method, the probability that a walker reaches a point a few steps away is calculated analytically and is stored in the computer. Instead of moving to the immediate neighboring point the walker is allowed to jump several steps further. The present multiple step random walk technique can be applied to both conventional Monte Carlo and the Exodus methods. Numerical results indicate that the present method compares well with finite difference solutions while the computation speed is much faster than that of single step Exodus and conventional Monte Carlo methods.

  18. Formation of the lunar crust - An electrical source of heating

    NASA Technical Reports Server (NTRS)

    Sonett, C. P.; Colburn, D. S.; Schwartz, K.

    1975-01-01

    A model for formation of the lunar crust based on heating by electrical induction is explored, while adherence is maintained to certain constraints associated with existing models of the solar system. The heating mechanism is based on eddy current induction from disordered magnetic fields swept outwards by an intense (T Tauri-like) plasma flow from the sun. The electrical theory is an alternative to intense short-period accretion as a source of heat for the evolution of lunar maria and highlands, provided that long-lived radioactives are not swept to the surface from too large a melt volume during the initial thermal episode. This formation of the lunar highlands does not intrinsically require rapid accretion, nor on this basis is the time of formation of the planets generally restricted to a very short time. The threshold temperature for eddy current heating is attained by either a solar nebula at 300-400 C during formation of the moon or a very low energy long-period accumulation of the moon, both leading to melting in ten to the fifth to ten to the seventh power years.

  19. Evaluation and characterization of General Purpose Heat Source girth welds for the Cassini mission

    SciTech Connect

    Lynch, C.M.; Moniz, P.F.; Reimus, M.A.H.

    1998-12-31

    General Purpose Heat Sources (GPHSs) are components of Radioisotopic thermoelectric Generators (RTGs) which provide electric power for deep space missions. Each GPHS consists of a {sup 238}Pu oxide ceramic pellet encapsulated in a welded iridium alloy shell which forms a protective barrier against the release of plutonia in the unlikely event of a launch-pad failure or reentry incident. GPHS fueled clad girth weld flaw detection was paramount to ensuring this safety function, and was accomplished using both destructive and non-destructive evaluation techniques. The first girth weld produced from each welding campaign was metallographically examined for flaws such as incomplete weld penetration, cracks, or porosity which would render a GPHS unacceptable for flight applications. After an acceptable example weld was produced, the subsequently welded heat sources were evaluated non-destructively for flaws using ultrasonic immersion testing. Selected heat sources which failed ultrasonic testing would be radiographed, and/or, destructively evaluated to further characterize and document anomalous indications. Metallography was also performed on impacted heat sources to determine the condition of the welds.

  20. Environmental and radiological safety studies: Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, September 26-December 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1982-02-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effect of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  1. Environmental and radiological safety studies. Interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 25, 1981

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1981-11-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  2. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, April 1- June 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-09-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources on terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  3. Environmental and radiological safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, July 1-September 30, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.; Stalnaker, N.D.

    1982-12-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  4. Salt disposal of heat-generating nuclear waste.

    SciTech Connect

    Leigh, Christi D.; Hansen, Francis D.

    2011-01-01

    This report summarizes the state of salt repository science, reviews many of the technical issues pertaining to disposal of heat-generating nuclear waste in salt, and proposes several avenues for future science-based activities to further the technical basis for disposal in salt. There are extensive salt formations in the forty-eight contiguous states, and many of them may be worthy of consideration for nuclear waste disposal. The United States has extensive experience in salt repository sciences, including an operating facility for disposal of transuranic wastes. The scientific background for salt disposal including laboratory and field tests at ambient and elevated temperature, principles of salt behavior, potential for fracture damage and its mitigation, seal systems, chemical conditions, advanced modeling capabilities and near-future developments, performance assessment processes, and international collaboration are all discussed. The discussion of salt disposal issues is brought current, including a summary of recent international workshops dedicated to high-level waste disposal in salt. Lessons learned from Sandia National Laboratories' experience on the Waste Isolation Pilot Plant and the Yucca Mountain Project as well as related salt experience with the Strategic Petroleum Reserve are applied in this assessment. Disposal of heat-generating nuclear waste in a suitable salt formation is attractive because the material is essentially impermeable, self-sealing, and thermally conductive. Conditions are chemically beneficial, and a significant experience base exists in understanding this environment. Within the period of institutional control, overburden pressure will seal fractures and provide a repository setting that limits radionuclide movement. A salt repository could potentially achieve total containment, with no releases to the environment in undisturbed scenarios for as long as the region is geologically stable. Much of the experience gained from United

  5. Isotope heat source simulator for testing of space power systems

    NASA Technical Reports Server (NTRS)

    Prok, G. M.; Smith, R. B.

    1973-01-01

    A reliable isotope heat source simulator was designed for use in a Brayton power system. This simulator is composed of an electrically heated tungsten wire which is wound around a boron nitride core and enclosed in a graphite jacket. Simulator testing was performed at the expected operating temperature of the Brayton power system. Endurance testing for 5012 hours was followed by cycling the simulator temperature. The integrity of this simulator was maintained throughout testing. Alumina beads served as a diffusion barrier to prevent interaction between the tungsten heater and boron nitride core. The simulator was designed to maintain a surface temperature of 1311 to 1366 K (1900 to 2000 F) with a power input of approximately 400 watts. The design concept and the materials used in the simulator make possible man different geometries. This flexibility increases its potential use.

  6. Cloud-generated radiative heating and its generation of available potential energy

    NASA Technical Reports Server (NTRS)

    Stuhlmann, R.; Smith, G. L.

    1989-01-01

    The generation of zonal available potential energy (APE) by cloud radiative heating is discussed. The APE concept was mathematically formulated by Lorenz (1955) as a measure of the maximum amount of total potential energy that is available for conversion by adiabatic processes to kinetic energy. The rate of change of APE is the rate of the generation of APE minus the rate of conversion between potential and kinetic energy. By radiative transfer calculations, a mean cloud-generated radiative heating for a well defined set of cloud classes is derived as a function of cloud optical thickness. The formulation is suitable for using a general cloud parameter data set and has the advantage of taking into account nonlinearities between the microphysical and macrophysical cloud properties and the related radiation field.

  7. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    PubMed

    Izumida, Yuki; Okuda, Koji

    2014-05-01

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart.

  8. Work output and efficiency at maximum power of linear irreversible heat engines operating with a finite-sized heat source.

    PubMed

    Izumida, Yuki; Okuda, Koji

    2014-05-01

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart. PMID:24856684

  9. Work Output and Efficiency at Maximum Power of Linear Irreversible Heat Engines Operating with a Finite-Sized Heat Source

    NASA Astrophysics Data System (ADS)

    Izumida, Yuki; Okuda, Koji

    2014-05-01

    We formulate the work output and efficiency for linear irreversible heat engines working between a finite-sized hot heat source and an infinite-sized cold heat reservoir until the total system reaches the final thermal equilibrium state with a uniform temperature. We prove that when the heat engines operate at the maximum power under the tight-coupling condition without heat leakage the work output is just half of the exergy, which is known as the maximum available work extracted from a heat source. As a consequence, the corresponding efficiency is also half of its quasistatic counterpart.

  10. A study of acoustic source generation mechanism of Magnetoacoustic Tomography.

    PubMed

    Wang, Shigang; Zhang, Shunqi; Ma, Ren; Yin, Tao; Liu, Zhipeng

    2014-01-01

    Magnetoacoustic Tomography (MAT) is a non-invasive imaging modality for electrical conductivity with good contrast and high spatial resolution. We have analyzed the acoustic source generation mechanism of MAT and presented its physical model, including the simulations and experiments in this paper. In MAT, acoustic sources are generated in a conductive object placed in a static magnetic field. Pulsed current is injected into the object and produces a Lorentz force due to the static magnetic filed. Acoustic vibration was excited by the Lorentz force, and hence, ultrasound waves propagate in all directions and are collected with transducers placed around the object. The conductivity image can then be reconstructed with acoustic waves using some reconstruction algorithms. Because the acoustic source generation mechanism of MAT is the key problem of forward and inverse problems, we analyzed the physical process of acoustic source generation and presented the acoustic dipole source model according to the Lorentz force imposed on the object. In addition, computer simulations and experiments were also conducted. The results of simulations applying an acoustic dipole source model are consistent with experimental results. This study has cardinal significance for the accurate algorithm of MAT and provides a methodology and reference for acoustic source problems.

  11. Ballistic heat transport in laser generated nano-bubbles.

    PubMed

    Lombard, Julien; Biben, Thierry; Merabia, Samy

    2016-08-01

    Nanobubbles generated by laser heated plasmonic nanoparticles are of interest for biomedical and energy harvesting applications. Of utmost importance is the maximal size of these transient bubbles. Here, we report hydrodynamic phase field simulations of the dynamics of laser induced nanobubbles, with the aim to understand which physical processes govern their maximal size. We show that the nanobubble maximal size and lifetime are to a large extent controlled by the ballistic thermal flux which is present inside the bubble. Taking into account this thermal flux, we can reproduce the fluence dependence of the maximal nanobubble radius as reported experimentally. We also discuss the influence of the laser pulse duration on the number of nanobubbles generated and their maximal size. These studies represent a significant step toward the optimization of the nanobubble size, which is of crucial importance for photothermal cancer therapy applications. PMID:27461058

  12. Ballistic heat transport in laser generated nano-bubbles.

    PubMed

    Lombard, Julien; Biben, Thierry; Merabia, Samy

    2016-08-01

    Nanobubbles generated by laser heated plasmonic nanoparticles are of interest for biomedical and energy harvesting applications. Of utmost importance is the maximal size of these transient bubbles. Here, we report hydrodynamic phase field simulations of the dynamics of laser induced nanobubbles, with the aim to understand which physical processes govern their maximal size. We show that the nanobubble maximal size and lifetime are to a large extent controlled by the ballistic thermal flux which is present inside the bubble. Taking into account this thermal flux, we can reproduce the fluence dependence of the maximal nanobubble radius as reported experimentally. We also discuss the influence of the laser pulse duration on the number of nanobubbles generated and their maximal size. These studies represent a significant step toward the optimization of the nanobubble size, which is of crucial importance for photothermal cancer therapy applications.

  13. Ballistic heat transport in laser generated nano-bubbles

    NASA Astrophysics Data System (ADS)

    Lombard, Julien; Biben, Thierry; Merabia, Samy

    2016-08-01

    Nanobubbles generated by laser heated plasmonic nanoparticles are of interest for biomedical and energy harvesting applications. Of utmost importance is the maximal size of these transient bubbles. Here, we report hydrodynamic phase field simulations of the dynamics of laser induced nanobubbles, with the aim to understand which physical processes govern their maximal size. We show that the nanobubble maximal size and lifetime are to a large extent controlled by the ballistic thermal flux which is present inside the bubble. Taking into account this thermal flux, we can reproduce the fluence dependence of the maximal nanobubble radius as reported experimentally. We also discuss the influence of the laser pulse duration on the number of nanobubbles generated and their maximal size. These studies represent a significant step toward the optimization of the nanobubble size, which is of crucial importance for photothermal cancer therapy applications.Nanobubbles generated by laser heated plasmonic nanoparticles are of interest for biomedical and energy harvesting applications. Of utmost importance is the maximal size of these transient bubbles. Here, we report hydrodynamic phase field simulations of the dynamics of laser induced nanobubbles, with the aim to understand which physical processes govern their maximal size. We show that the nanobubble maximal size and lifetime are to a large extent controlled by the ballistic thermal flux which is present inside the bubble. Taking into account this thermal flux, we can reproduce the fluence dependence of the maximal nanobubble radius as reported experimentally. We also discuss the influence of the laser pulse duration on the number of nanobubbles generated and their maximal size. These studies represent a significant step toward the optimization of the nanobubble size, which is of crucial importance for photothermal cancer therapy applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/C6NR02144A

  14. Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

    PubMed

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

    The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis.

  15. Effects of aqueous humor hydrodynamics on human eye heat transfer under external heat sources.

    PubMed

    Tiang, Kor L; Ooi, Ean H

    2016-08-01

    The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-dimensional model of the human eye is developed to investigate the effects AH hydrodynamics have on the human eye temperature under exposure to external heat sources. If the effects of AH flow are negligible, then future models can be developed without taking them into account, thus simplifying the modeling process. Two types of external thermal loads are considered; volumetric and surface irradiation. Results showed that heat convection due to AH flow contributes to nearly 95% of the total heat flow inside the anterior chamber. Moreover, the circulation inside the anterior chamber can cause an upward shift of the location of hotspot. This can have significant consequences to our understanding of heat-induced cataractogenesis. PMID:27340100

  16. Model of heat and mass transfer by fluid during formation of Mo-U deposits in the Strel'tsovka ore field, eastern Transbaikal region: Forced convection of solutions generated by a deep source

    NASA Astrophysics Data System (ADS)

    Malkovsky, V. I.; Pek, A. A.; Aleshin, A. P.; Velichkin, V. I.

    2010-02-01

    The Strel’tsovka and Antei uranium deposits located in the Strel’tsovka caldera are unique in ore resources. According to the considered mathematical model, the uranium source of these deposits was related to the middle-lower crustal silicic magma chambers or had mantle origin. Boundary conditions of the model are based on modern views of physicochemical conditions of hydrothermal process in the Strel’tsovka ore field and factors governing ore deposition therein. Modeling results are consistent with morphology of orebodies and ultimate uranium resources of the deposits and thus confirm indirectly that the physicochemical parameters of the ore-forming system are coherent. The maximal duration of uranium ore deposition is estimated at 500 ka.

  17. Effects of a Ground Source Heat Pump in Discontinuous Permafrost

    NASA Astrophysics Data System (ADS)

    Peterson, R.; Garber-Slaght, R.; Daanen, R. P.

    2015-12-01

    A ground source heat pump (GSHP) was installed in a discontinuous permafrost region of Fairbanks Alaska in 2013 with the primary aim of determining the effect of different ground cover options on the long-term subterranean temperature regime. Three different surface treatments were applied to separate loops of the GSHP; grass, sand, and gravel, and temperature monitoring was established at several depths above and below the heat sink loops. The GSHP has been actively utilized to supplement the heat in a hydronic heating system of a neighboring 5000 ft2 research facility. The ground immediately surrounding the GSHP was not permafrost when initially installed. Numerical modeling simulations were used to predict the long-term ground temperature regime surrounding the GSHP loops, and results indicate that permafrost would begin to form after the first year. A pseudo-steady state temperature regime would establish in approximately 8 years with a yearly fluctuation of -14°C to -2°C. Simulations also indicate that permafrost could be prevented with a 15 W/m recharge during the summer, such as from a solar thermal system. The ground surface treatments have negligible effect on the ground temperature below 1 meter and therefore have no long-term effect on the active region the GSHP. Data collected from thermistors in the two years since installation indicate that permafrost has not yet been established, although the ground is now becoming seasonally frozen due to the GSHP energy removal. Yearly average temperatures are declining, and extrapolation indicates that permafrost will establish in future years. The GSHP coefficient of performance (COP) was initially 3.6 and is declining with the decreasing ground temperatures. Economic modeling indicates that the system may become uneconomical in future years, although volatile energy costs have a substantial effect of the prediction.

  18. Laser-Generated Thermoelastic Acoustic Sources in Anisotropic Materials

    SciTech Connect

    David H. Hurley

    2004-05-01

    An analytical model appropriate for thermoelastic generation of acoustic waves in anisotropic materials is presented for both plane and line sources. The interaction of acoustic waves produced by subsurface sources with the bounding surface is accounted for using a method of images. For the plane source case, analytical solutions are found that form an appropriate basis for an angular spectrum of plane waves. For the line source case and for specific crystal symmetries and source orientations, it is shown in the limit of strong optical absorption, a buried line source is equivalent to applying a shear stress dipole at the bounding surface. However, contrary to the isotropic case, the character and strength of the equivalent surface stress is a function of propagation direction.

  19. Heat flow and heat generation estimates for the Churchill basement of the Western Canadian Basin in Alberta, Canada

    SciTech Connect

    Beach, R.D.W.; Jones, F.W.; Majorowicz, J.A.

    1987-01-01

    Heat flow through the sediments and temperatures of the Churchill province basement under the sedimentary cover are determined for 24 locations in the central part of the Prairies basin in Alberta where the vertical heat flux is approximately constant from the base of the sediments to the surface. The contribution to heat flow from heat generation in the sediments is also considered. The average heat flow through the sediments is found to be 71 mWm/sup -2/ +- 12mWm/sup -2/ which is about 30 mWm/sup -2/ higher than in the neighbouring shield area of the Churchill province, and the contribution from heat generation in the sediments to the surface heat flow is only approximately 2.5 mWm/sup -2/. The relationship between basement heat generation and heat flow is investigated, and it is found that the platform heat flow/heat generation values are in general higher than those from the Churchill province of the shield found by Drury (1985). Although for the platform and shield data, the reduced heat flow is about 40 mWm/sup -2/ and the slope is about 8km, it is apparent that the platform data alone are not good enough to establish a precise relationship.

  20. Recovery Act: Cedarville School District Retrofit of Heating and Cooling Systems with Geothermal Heat Pumps and Ground Source Water Loops

    SciTech Connect

    Jarrell, Mark

    2013-09-30

    Cedarville School District retrofitted the heating and cooling systems in three campus areas (High School, Middle School, and Upper Elementary School) with geothermal heat pumps and ground source water loops, as a demonstration project for the effective implementation of geothermal heat pump systems and other energy efficiency and air quality improvements.

  1. Fifth-Generation Free-Electron Laser Light Sources

    SciTech Connect

    Pellegrini, Claudio

    2011-03-02

    During the past few years, the Linac Coherent Light Source (LCLS) and the Free-Electron Laser in Hamburg (FLASH) have demonstrated the outstanding capability of free-electron lasers (FELs) as sources of coherent radiation in the soft and hard x-ray region. The high intensity, tens of GW, short pulses (few to less than 100 femtoseconds, and the unique transverse coherence properties are opening a new window to study the structure and dynamics of atomic and molecular systems. The LCLS, FLASH, and the other FELs now under construction are only the beginning of the development of these light sources. The next generations will reach new levels of performance: terawatt, atto-second, ultra-small line-width, high repetition rate, full longitudinal and transverse coherence. These future developments and the R&D needed to successfully build and operate the next generation of FEL light sources will be discussed.

  2. On the efficient use of a lowtemperature heat source by the organic Rankine cycle

    NASA Astrophysics Data System (ADS)

    Mikielewicz, Dariusz; Mikielewicz, Jarosław

    2013-09-01

    The evaporation temperature is regarded as one of the major parameters influencing the organic Rankine cycle (ORC) efficiency. Majority of contributions in literature for ORC cycle analyses treat the heat source as if it had an infinite heat capacity. Such analyses are not valuable as the resulting temperature drops of the heat source needs to be small. That leads to the fact that the heat source is not well explored and in the case of waste heat utilization it can prove the poor economics of the ORC. In the present study cooperation of the ORC cycle with the heat source available as a single phase or phase changing fluids is considered. The analytical heat balance models have been developed, which enable in a simple way calculation of heating fluid temperature variation as well as the ratio of flow rates of heating and working fluids in ORC cycle. The developed analytical expressions enable also calculation of the outlet temperature of the heating fluid.

  3. Flow of a non-linear (density-gradient-dependent) viscous fluid with heat generation, viscous dissipation and radiation

    SciTech Connect

    Massoudi, Mehrdad; Phuoc, Tran X.

    2008-09-25

    In this paper, we study the flow of a compressible (density-gradient-dependent) non-linear fluid down an inclined plane, subject to radiation boundary condition. The convective heat transfer is also considered where a source team, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed.

  4. Flow of a non-linear (density-gradient-dependent) viscous fluid with heat generation, viscous dissipation and radiation

    SciTech Connect

    Massoudi, Mehrdad; Tran, P.X.

    2008-09-22

    In this paper, we study the flow of a compressible (density-gradient-dependent) non-linear fluid down an inclined plane, subject to radiation boundary condition. The convective heat transfer is also considered where a source term, similar to the Arrhenius type reaction, is included. The non-dimensional forms of the equations are solved numerically and the competing effects of conduction, dissipation, heat generation and radiation are discussed

  5. Performance analysis of ORC power generation system with low-temperature waste heat of aluminum reduction cell

    NASA Astrophysics Data System (ADS)

    Wang, Zhiqi; Zhou, Naijun; Jing, Guo

    Performance of organic Rankine cycle (ORC) system to recover low-temperature waste heat from aluminum reduction cell was analyzed. The temperature of waste heat is 80°C-200°C and the flow rate is 3×105m3/h. The pinch temperature difference between waste heat and working fluids is 10°C. The results show that there is optimal evaporating temperature for maximum net power under the same pinch point. For heat source temperature range of 80°C-140°C and 150°C-170°C, the working fluid given biggest net power is R227ea and R236fa, respectively. When the temperature is higher than 180°C, R236ea generates the biggest net power. The variation of heat source temperature has important effect on net power. When the temperature decreases 10%, the net power will deviate 30% from the maximum value.

  6. The planetary distribution of heat sources and sinks during FGGE

    NASA Technical Reports Server (NTRS)

    Johnson, D. R.; Wei, M. Y.

    1985-01-01

    Heating distributions from analysis of the National Meteorological Center and European Center for Medium Range Weather Forecasts data sets; methods used and problems involved in the inference of diabatic heating; the relationship between differential heating and energy transport; and recommendations on the inference of heat soruces and heat sinks for the planetary show are discussed.

  7. A novel pyroelectric generator utilising naturally driven temperature fluctuations from oscillating heat pipes for waste heat recovery and thermal energy harvesting

    NASA Astrophysics Data System (ADS)

    Zabek, D.; Taylor, J.; Ayel, V.; Bertin, Y.; Romestant, C.; Bowen, C. R.

    2016-07-01

    Low temperature thermal to electrical energy converters have the potential to provide a route for recovering waste energy. In this paper, we propose a new configuration of a thermal harvester that uses a naturally driven thermal oscillator free of mechanical motion and operates between a hot heat source and a cold heat sink. The system exploits a heat induced liquid-vapour transition of a working fluid as a primary driver for a pyroelectric generator. The two-phase instability of a fluid in a closed looped capillary channel of an oscillating heat pipe (OHP) creates pressure differences which lead to local high frequency temperature oscillations in the range of 0.1-5 K. Such temperature changes are suitable for pyroelectric thermal to electrical energy conversion, where the pyroelectric generator is attached to the adiabatic wall of the OHP, thereby absorbing thermal energy from the passing fluid. This new pyroelectric-oscillating heat pipe (POHP) assembly of a low temperature generator continuously operates across a spatial heat source temperature of 55 °C and a heat sink temperature of 25 °C, and enables waste heat recovery and thermal energy harvesting from small temperature gradients at low temperatures. Our electrical measurements with lead zirconate titanate (PZT) show an open circuit voltage of 0.4 V (AC) and with lead magnesium niobate-lead titanate (PMN-PT) an open circuit voltage of 0.8 V (AC) at a frequency of 0.45 Hz, with an energy density of 95 pJ cm-3 for PMN-PT. Our novel POHP device therefore has the capability to convert small quantities of thermal energy into more desirable electricity in the nW to mW range and provides an alternative to currently used batteries or centralised energy generation.

  8. Generation of mirage effect by heated carbon nanotube thin film

    NASA Astrophysics Data System (ADS)

    Tong, L. H.; Lim, C. W.; Li, Y. C.; Zhang, Chuanzeng; Quoc Bui, Tinh

    2014-06-01

    Mirage effect, a common phenomenon in nature, is a naturally occurring optical phenomenon in which lights are bent due to the gradient variation of refraction in the temperature gradient medium. The theoretical analysis of mirage effect generated by heated carbon nanotube thin film is presented both for gas and liquid. Excellent agreement is demonstrated through comparing the theoretical prediction with published experimental results. It is concluded from the theoretical prediction and experimental observation that the mirage effect is more likely to happen in liquid. The phase of deflected optical beam is also discussed and the method for measurement of thermal diffusivity of medium is theoretically verified. Furthermore, a method for measuring the refractive index of gas by detecting optical beam deflection is also presented in this paper.

  9. Generation of mirage effect by heated carbon nanotube thin film

    SciTech Connect

    Tong, L. H.; Lim, C. W.; Li, Y. C.; Zhang, Chuanzeng; Quoc Bui, Tinh

    2014-06-28

    Mirage effect, a common phenomenon in nature, is a naturally occurring optical phenomenon in which lights are bent due to the gradient variation of refraction in the temperature gradient medium. The theoretical analysis of mirage effect generated by heated carbon nanotube thin film is presented both for gas and liquid. Excellent agreement is demonstrated through comparing the theoretical prediction with published experimental results. It is concluded from the theoretical prediction and experimental observation that the mirage effect is more likely to happen in liquid. The phase of deflected optical beam is also discussed and the method for measurement of thermal diffusivity of medium is theoretically verified. Furthermore, a method for measuring the refractive index of gas by detecting optical beam deflection is also presented in this paper.

  10. Resistively Heated SiC Nozzle for Generating Molecular Beams

    NASA Technical Reports Server (NTRS)

    Cagiano, Steven; Abell, Robert; Patrick, Edward; Bendt, Miri; Gundersen, Cynthia

    2007-01-01

    An improved nozzle has been developed to replace nozzles used previously in an apparatus that generates a substantially unidirectional beam of molecules passing through a vacuum at speeds of several kilometers per second. The basic principle of operation of the apparatus is the same for both the previous and the present nozzle designs. The main working part of the nozzle is essentially a cylinder that is closed except that there is an inlet for a pressurized gas and, at one end, the cylinder is closed by a disk that contains a narrow central hole that serves as an outlet. The cylinder is heated to increase the thermal speeds of the gas molecules into the desired high-speed range. Heated, pressurized gas escapes through the outlet into a portion of the vacuum chamber that is separated, by a wall, from the rest of the vacuum chamber. In this portion of the vacuum chamber, the gas undergoes a free jet expansion. Most of the expanded gas is evacuated and thus does not become part of the molecular beam. A small fraction of the expanded beam passes through a narrow central orifice in the wall and thereby becomes a needle- thin molecular beam in the portion of the vacuum on the downstream side of the wall.

  11. Dynamic conversion of solar generated heat to electricity

    NASA Technical Reports Server (NTRS)

    Powell, J. C.; Fourakis, E.; Hammer, J. M.; Smith, G. A.; Grosskreutz, J. C.; Mcbride, E.

    1974-01-01

    The effort undertaken during this program led to the selection of the water-superheated steam (850 psig/900 F) crescent central receiver as the preferred concept from among 11 candidate systems across the technological spectrum of the dynamic conversion of solar generated heat to electricity. The solar power plant designs were investigated in the range of plant capacities from 100 to 1000 Mw(e). The investigations considered the impacts of plant size, collector design, feed-water temperature ratio, heat rejection equipment, ground cover, and location on solar power technical and economic feasibility. For the distributed receiver systems, the optimization studies showed that plant capacities less than 100 Mw(e) may be best. Although the size of central receiver concepts was not parametrically investigated, all indications are that the optimal plant capacity for central receiver systems will be in the range from 50 to 200 Mw(e). Solar thermal power plant site selection criteria and methodology were also established and used to evaluate potentially suitable sites. The result of this effort was to identify a site south of Inyokern, California, as typically suitable for a solar thermal power plant. The criteria used in the selection process included insolation and climatological characteristics, topography, and seismic history as well as water availability.

  12. Investigation of acoustic gravity waves created by anomalous heat sources: experiments and theoretical analysis

    NASA Astrophysics Data System (ADS)

    Pradipta, R.; Lee, M. C.

    2013-07-01

    We have been investigating high-power radio wave-induced acoustic gravity waves (AGWs) at Gakona, Alaska, using the High-frequency Active Aurora Research Program (HAARP) heating facility (i.e. HF heater) and extensive diagnostic instruments. This work was aimed at performing a controlled study of the space plasma turbulence triggered by the AGWs originating from anomalous heat sources, as observed in our earlier experiments at Arecibo, Puerto Rico (Pradipta 2007 MS Thesis MIT Press, Cambridge, MA). The HF heater operated in continuous wave (CW) O-mode can heat ionospheric plasmas effectively to yield a depleted magnetic flux tube as rising plasma bubbles (Lee et al 1998 Geophys. Res. Lett. 25 579). Two processes are responsible for the depletion of the magnetic flux tube: (i) thermal expansion and (ii) chemical reactions caused by heated ions. The depleted plasmas create large density gradients that can augment spread F processes via generalized Rayleigh-Taylor instabilities (Lee et al 1999 Geophys. Res. Lett. 26 37). It is thus expected that the temperature of neutral particles in the heated ionospheric region can be increased. Such a heat source in the neutral atmosphere may potentially generate AGWs in the form of traveling ionospheric plasma disturbances (TIPDs). We should point out that these TIPDs have features distinctively different from electric and magnetic field (ExB) drifts of HF wave-induced large-scale non-propagating plasma structures. Moreover, it was noted in our recent study of naturally occurring AGW-induced TIDs that only large-scale AGWs can propagate upward to reach higher altitudes. Thus, in our Gakona experiments we select optimum heating schemes for HF wave-induced AGWs that can be distinguished from the naturally occurring ones. The generation and propagation of AGWs are monitored by MUIR (Modular Ultra high-frequency Ionospheric Radar), Digisonde and GPS/low-earth-orbit satellites. Our theoretical and experimental studies have shown that

  13. A field evaporation deuterium ion source for neutron generators

    SciTech Connect

    Reichenbach, Birk; Solano, I.; Schwoebel, P. R.

    2008-05-01

    Proof-of-principle experiments have demonstrated an electrostatic field evaporation based deuterium ion source for use in compact, high-output deuterium-tritium neutron generators. The ion source produces principally atomic deuterium and titanium ions. More than 100 ML of deuterated titanium thin film can be removed and ionized from a single tip in less than 20 ns. The measurements indicate that with the use of microfabricated tip arrays the deuterium ion source could provide sufficient ion current to produce 10{sup 9}-10{sup 10} n/cm{sup 2} of tip array area.

  14. A field evaporation deuterium ion source for neutron generators

    NASA Astrophysics Data System (ADS)

    Reichenbach, Birk; Solano, I.; Schwoebel, P. R.

    2008-05-01

    Proof-of-principle experiments have demonstrated an electrostatic field evaporation based deuterium ion source for use in compact, high-output deuterium-tritium neutron generators. The ion source produces principally atomic deuterium and titanium ions. More than 100 ML of deuterated titanium thin film can be removed and ionized from a single tip in less than 20 ns. The measurements indicate that with the use of microfabricated tip arrays the deuterium ion source could provide sufficient ion current to produce 109-1010 n/cm2 of tip array area.

  15. Irreversibilities and efficiency at maximum power of heat engines: the illustrative case of a thermoelectric generator.

    PubMed

    Apertet, Y; Ouerdane, H; Goupil, C; Lecoeur, Ph

    2012-03-01

    Energy conversion efficiency at maximum output power, which embodies the essential characteristics of heat engines, is the main focus of the present work. The so-called Curzon and Ahlborn efficiency η(CA) is commonly believed to be an absolute reference for real heat engines; however, a different but general expression for the case of stochastic heat engines, η(SS), was recently found and then extended to low-dissipation engines. The discrepancy between η(CA) and η(SS) is here analyzed considering different irreversibility sources of heat engines, of both internal and external types. To this end, we choose a thermoelectric generator operating in the strong-coupling regime as a physical system to qualitatively and quantitatively study the impact of the nature of irreversibility on the efficiency at maximum output power. In the limit of pure external dissipation, we obtain η(CA), while η(SS) corresponds to the case of pure internal dissipation. A continuous transition between from one extreme to the other, which may be operated by tuning the different sources of irreversibility, also is evidenced.

  16. Irreversibilities and efficiency at maximum power of heat engines: the illustrative case of a thermoelectric generator.

    PubMed

    Apertet, Y; Ouerdane, H; Goupil, C; Lecoeur, Ph

    2012-03-01

    Energy conversion efficiency at maximum output power, which embodies the essential characteristics of heat engines, is the main focus of the present work. The so-called Curzon and Ahlborn efficiency η(CA) is commonly believed to be an absolute reference for real heat engines; however, a different but general expression for the case of stochastic heat engines, η(SS), was recently found and then extended to low-dissipation engines. The discrepancy between η(CA) and η(SS) is here analyzed considering different irreversibility sources of heat engines, of both internal and external types. To this end, we choose a thermoelectric generator operating in the strong-coupling regime as a physical system to qualitatively and quantitatively study the impact of the nature of irreversibility on the efficiency at maximum output power. In the limit of pure external dissipation, we obtain η(CA), while η(SS) corresponds to the case of pure internal dissipation. A continuous transition between from one extreme to the other, which may be operated by tuning the different sources of irreversibility, also is evidenced. PMID:22587047

  17. Design of Isotope Heat Source for Automatic Modular Dispersal During Reentry, and Its Integration with Heat Exchangers of 6-kWe Dynamic Isotope Power System

    SciTech Connect

    Schock, Alfred

    1989-01-01

    In late 1986 the Air Force Space Division (AF / SD) had expressed an interest in using a Dynamic Isotope Power System (DIPS) of approximately 6-kWe to power the Boost Surveillance and Tacking System (BSTS) satellites. In support of that objective, the U.S. Department of Energy (DOE) requested Fairchild Space Company to perform a conceptual design study of the DIPS heat source and of its integration with the dynamic power conversion system, with particular emphasis on system safety. This paper describes the results of that study. The study resulted in a design for a single heat source of ~30-kWt, employing the standard 250-W General Purpose Heat Source (GPHS) modules which DOE had previously developed and safety-tested for Radioisotope Thermoelectric Generators (RTS's)

  18. CMOS MEMS-based thermoelectric generator with an efficient heat dissipation path

    NASA Astrophysics Data System (ADS)

    Yu, Xiao; Wang, Yuchen; Liu, Yanxiang; Li, Tie; Zhou, Hong; Gao, Xiuli; Feng, Fei; Roinila, Tomi; Wang, Yuelin

    2012-10-01

    This paper presents a CMOS MEMS-based thermoelectric energy generator (TEG) device with an efficient heat dissipation path. For present CMOS MEMS-based thermoelectric generator devices, the output performance is greatly limited by the high thermal-contact resistance in the system. For the device proposed in the work, the silicon substrate is etched into two comb-shaped blocks thermally isolated from each other, which form the hot and cold sides. Thin-film-based thermal legs are densely located between the two blocks along the winding split line. Low internal thermal-contact resistance is achieved with the symmetrical thermal structure. When the TEG device is embedded between the heat source and heat sink, the heat loss can be well controlled with flat thermal-contact pads of the device. For a full device with 900 n/p-polysilicon thermocouples, the measured open-circuit voltage reaches as high as 146 mV K-1, and the power factor reaches almost five times higher value compared to the previously reported results. A test system integrated with a single device presents an open-circuit voltage of 110 mV K-1 when forcibly cooled by a Peltier cooler, or 26 mV K-1 when cooled by ambient air.

  19. High-efficiency target-ion sources for RIB generation

    SciTech Connect

    Alton, G.D.

    1993-12-31

    A brief review is given of high-efficiency ion sources which have been developed or are under development at ISOL facilities which show particular promise for use at existing, future, or radioactive ion beam (RIB) facilities now under construction. Emphasis will be placed on those sources which have demonstrated high ionization efficiency, species versatility, and operational reliability and which have been carefully designed for safe handling in the high level radioactivity radiation fields incumbent at such facilities. Brief discussions will also be made of the fundamental processes which affect the realizable beam intensities in target-ion sources. Among the sources which will be reviewed will be selected examples of state-of-the-art electron-beam plasma-type ion sources, thermal-ionization, surface-ionization, ECR, and selectively chosen ion source concepts which show promise for radioactive ion beam generation. A few advanced, chemically selective target-ion sources will be described, such as sources based on the use of laser-resonance ionization, which, in principle, offer a more satisfactory solution to isobaric contamination problems than conventional electromagnetic techniques. Particular attention will be given to the sources which have been selected for initial or future use at the Holifield Radioactive Ion Beam Facility now under construction at the Oak Ridge National Laboratory.

  20. Hydrogen production from coal using a nuclear heat source

    NASA Technical Reports Server (NTRS)

    Quade, R. N.

    1976-01-01

    A strong candidate for hydrogen production in the intermediate time frame of 1985 to 1995 is a coal-based process using a high-temperature gas-cooled reactor (HTGR) as a heat source. Expected process efficiencies in the range of 60 to 70% are considerably higher than all other hydrogen production processes except steam reforming of a natural gas. The process involves the preparation of a coal liquid, hydrogasification of that liquid, and steam reforming of the resulting gaseous or light liquid product. A study showing process efficiency and cost of hydrogen vs nuclear reactor core outlet temperature has been completed, and shows diminishing returns at process temperatures above about 1500 F. A possible scenario combining the relatively abundant and low-cost Western coal deposits with the Gulf Coast hydrogen users is presented which provides high-energy density transportation utilizing coal liquids and uranium.

  1. Model of Heat Exchangers for Waste Heat Recovery from Diesel Engine Exhaust for Thermoelectric Power Generation

    NASA Astrophysics Data System (ADS)

    Baker, Chad; Vuppuluri, Prem; Shi, Li; Hall, Matthew

    2012-06-01

    The performance and operating characteristics of a hypothetical thermoelectric generator system designed to extract waste heat from the exhaust of a medium-duty turbocharged diesel engine were modeled. The finite-difference model consisted of two integrated submodels: a heat exchanger model and a thermoelectric device model. The heat exchanger model specified a rectangular cross-sectional geometry with liquid coolant on the cold side, and accounted for the difference between the heat transfer rate from the exhaust and that to the coolant. With the spatial variation of the thermoelectric properties accounted for, the thermoelectric device model calculated the hot-side and cold-side heat flux for the temperature boundary conditions given for the thermoelectric elements, iterating until temperature and heat flux boundary conditions satisfied the convection conditions for both exhaust and coolant, and heat transfer in the thermoelectric device. A downhill simplex method was used to optimize the parameters that affected the electrical power output, including the thermoelectric leg height, thermoelectric n-type to p-type leg area ratio, thermoelectric leg area to void area ratio, load electrical resistance, exhaust duct height, coolant duct height, fin spacing in the exhaust duct, location in the engine exhaust system, and number of flow paths within the constrained package volume. The calculation results showed that the configuration with 32 straight fins was optimal across the 30-cm-wide duct for the case of a single duct with total height of 5.5 cm. In addition, three counterflow parallel ducts or flow paths were found to be an optimum number for the given size constraint of 5.5 cm total height, and parallel ducts with counterflow were a better configuration than serpentine flow. Based on the reported thermoelectric properties of MnSi1.75 and Mg2Si0.5Sn0.5, the maximum net electrical power achieved for the three parallel flow paths in a counterflow arrangement was 1

  2. A new laser source for ultrasound generation in composites

    NASA Astrophysics Data System (ADS)

    Lorraine, Peter W.; Dubois, Marc; Bauco, Anthony S.; Filkins, Robert J.; Drake, T. E.; Yawn, K. R.

    2000-05-01

    Laser ultrasound is proving to be a cost-effective means for inspecting composite components. Ultrasound is typically generated with a pulse of 10.6 micron light from a TEA CO2 laser. In this paper, we report on experimental progress towards a new source laser with improved characteristics.

  3. The Physical Basis of Lg Generation by Explosion Sources

    SciTech Connect

    J. L. Stevens; G. E. Baker; H. Xu; T. J. Bennett; N. Rimer; S. D. Day

    2004-12-20

    The goal of this project has been to develop a quantitative predictive capability for explosion-generated Lg phases with a sound and unambiguous physical basis. The research program consisted of a theoretical investigation of explosion-generated Lg combined with an observational study. The specific question addressed by this research program is how the Lg phase is generated by underground nuclear explosions. This question is fundamental to how Lg phases are interpreted for use in explosion yield estimation and earthquake/explosion discrimination. To constrain modeling, we have extensively reviewed the existing literature and complemented that work with an examination of several explosion data sets, most notably: (1) Degelen Mountain explosions recorded between 7 and 57 km, with corresponding recordings at Borovoye, at approximately 650 km; (2) recordings from Russian deep seismic sounding experiments; (3) NTS explosion sources including the NPE and nuclear tests covering a range of source depths and media properties. A simple point explosion in an infinite medium generates no shear waves, so the Lg phase is generated entirely by non-spherical components of the source and conversions through reflections and scattering. We find that the most important contributors to the Lg phase are: (1) P to S conversion at the free surface and other near source interfaces, (2) S waves generated directly by a realistically distributed explosion source including nonlinear effects due to the free surface and gravity, and (3) Rg scattering to Lg. Additional effects that contribute significantly to Lg are scattering of converted S phases that traps more of the converted P-to-S in the crust, and randomization of the components of Lg. The pS phase from a spherically symmetric explosion source in media with P-wave velocity less than upper mantle S-wave velocity is trapped in the crust and can explain the observed radial and vertical Lg. The free surface pS converted phase from the same

  4. Strategic GHG reduction through the use of ground source heat pump technology

    NASA Astrophysics Data System (ADS)

    Hanova, J.; Dowlatabadi, H.

    2007-10-01

    Higher energy prices and concern about climate change is drawing increasing attention to ground source heat pump (GSHP) systems. Their clear advantage lies in being able to provide heating using 25 to 30% of the energy consumed by even the most efficient conventional alternatives. Their drawback has been high capital costs and uncertainty about whether the emissions associated with the electric power used to energise the system has higher system-wide emissions than the highest-efficiency furnaces. This study delineates circumstances under which GSHP systems achieve net emission reductions, for different electricity generation methods, heat pump efficiencies, and heating loads. We illustrate the effect of relative fuel prices on annual operating savings using fuel prices in multiple countries. Annual operating savings determine how rapidly the technology achieves payback and then generates return on the initial capital investment. Finally, we highlight the least cost supply curve for using GSHP to reduce greenhouse gas emissions. Using the United States as a base reference case, this study explores the potential of GSHP in cold-climate countries worldwide.

  5. A positive (negative) surface ionization source concept for RIB generation

    SciTech Connect

    Alton, G.D.; Mills, G.D.

    1995-12-31

    A novel, versatile, new concept, spherical-geometry, positive (negative) surface-ionization source has been designed and fabricated which will have the capability of generating both positive- and negative-ion beams without mechanical changes to the source. The source utilizes a highly permeable, high-work-function Ir ionizer ({phi}{approximately} = 5.29 eV) for ionizing highly electropositive atoms/molecules; while for negative-surface ionization, the work function is lowered to {phi} {approximately} = 1.43 eV by continually feeding cesium vapor through the ionizer matrix. The use of Cs to effect low work function surfaces for negative ion beam generation has the potential of overcoming the chronic poisoning effects experienced with LaB{sub 6} while enhancing the probability for negative ion formation of atomic and molecular species with low to intermediate electron affinities. The flexibility of operation in either mode makes it especially attractive for RIB applications and, therefore, the source will be used as a complementary replacement for the high-temperature electron impact ionization sources presently in use at the HRIBF The design features and operational principles of the source will be described in this report.

  6. The analysis of a reactive hydromagnetic internal heat generating poiseuille fluid flow through a channel.

    PubMed

    Hassan, A R; Maritz, R

    2016-01-01

    In this paper, the analysis of a reactive hydromagnetic Poiseuille fluid flow under different chemical kinetics through a channel in the presence of a heat source is carried out. An exothermic reaction is assumed while the concentration of the material is neglected. The Adomian decomposition method together with Pade approximation technique are used to obtain the solutions of the governing nonlinear non-dimensional differential equations. Effects of various physical parameters on the velocity and temperature fields of the fluid flow are investigated. The entropy generation analysis, irreversibility distribution ratio, Bejan number and the conditions for thermal criticality for different chemical kinetics are also presented. PMID:27563527

  7. Heat Source Neutron Emission Rate Reduction Studies - Water Induced HF Liberation

    NASA Astrophysics Data System (ADS)

    Matonic, John; Brown, John; Foltyn, Liz; Garcia, Lawrence; Hart, Ron; Herman, David; Huling, Jeff; Pansoy-Hjelvik, M. E. Lisa; Sandoval, Fritz; Spengler, Diane

    2004-02-01

    Plutonium-238 oxide (238PuO2) is used in the fabrication of general purpose heat sources (GPHS) or light-weight radioisotope heater units (LWRHUs). The heat sources supply the thermal energy used in radioisotope thermoelectric generators to power spacecraft for deep space missions and to heat critical components in the cold environs of space. Los Alamos National Laboratory has manufactured heat sources for approximately two decades. The aqueous purification of 238PuO2 is required, due to rigorous total Pu-content, actinide and non-actinide metal impurity, and neutron emission rate specifications. The 238PuO2 aqueous purification process is a new capability at Los Alamos National Laboratory as previously, aqueous purified 238PuO2 occurred at other DOE complexes. The Pu-content and actinide and non-actinide metal impurity specifications are met well within specification in the Los Alamos process, though reduction in neutron emission rates have been challenging. High neutron emission rates are typically attributed to fluoride content in the oxide. The alpha decay from 238Pu results in α,n reactions with light elements such as 17O, 18O, and 19F resulting in high neutron emission rates in the purified 238PuO2. Simple 16O-exchange takes care of the high NER due to 17O, and 18O. A new method to reduce the NER due to 19F in the purified 238PuO2 is presented in this paper. The method involves addition of water to purified 238PuO2, followed by heating to remove the water and liberating fluoride as HF.

  8. DOS-HEATING6: A general conduction code with nuclear heat generation derived from DOT-IV transport calculations

    SciTech Connect

    Williams, M.L.; Yuecel, A.; Nadkarny, S.

    1988-05-01

    The HEATING6 heat conduction code is modified to (a) read the multigroup particle fluxes from a two-dimensional DOT-IV neutron- photon transport calculation, (b) interpolate the fluxes from the DOT-IV variable (optional) mesh to the HEATING6 control volume mesh, and (c) fold the interpolated fluxes with kerma factors to obtain a nuclear heating source for the heat conduction equation. The modified HEATING6 is placed as a module in the ORNL discrete ordinates system (DOS), and has been renamed DOS-HEATING6. DOS-HEATING6 provides the capability for determining temperature distributions due to nuclear heating in complex, multi-dimensional systems. All of the original capabilities of HEATING6 are retained for the nuclear heating calculation; e.g., generalized boundary conditions (convective, radiative, finned, fixed temperature or heat flux), temperature and space dependent thermal properties, steady-state or transient analysis, general geometry description, etc. The numerical techniques used in the code are reviewed and the user input instructions and JCL to perform DOS-HEATING6 calculations are presented. Finally a sample problem involving coupled DOT-IV and DOS-HEATING6 calculations of a complex space-reactor configurations described, and the input and output of the calculations are listed. 10 refs., 11 figs., 6 tabs.

  9. Surface plasma source with saddle antenna radio frequency plasma generator.

    PubMed

    Dudnikov, V; Johnson, R P; Murray, S; Pennisi, T; Piller, C; Santana, M; Stockli, M; Welton, R

    2012-02-01

    A prototype RF H(-) surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA∕kW. Control experiments with H(-) beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  10. Surface plasma source with saddle antenna radio frequency plasma generator

    SciTech Connect

    Dudnikov, V.; Johnson, R. P.; Murray, S.; Pennisi, T.; Piller, C.; Santana, M.; Stockli, M.; Welton, R.

    2012-02-15

    A prototype RF H{sup -} surface plasma source (SPS) with saddle (SA) RF antenna is developed which will provide better power efficiency for high pulsed and average current, higher brightness with longer lifetime and higher reliability. Several versions of new plasma generators with small AlN discharge chambers and different antennas and magnetic field configurations were tested in the plasma source test stand. A prototype SA SPS was installed in the Spallation Neutron Source (SNS) ion source test stand with a larger, normal-sized SNS AlN chamber that achieved unanalyzed peak currents of up to 67 mA with an apparent efficiency up to 1.6 mA/kW. Control experiments with H{sup -} beam produced by SNS SPS with internal and external antennas were conducted. A new version of the RF triggering plasma gun has been designed. A saddle antenna SPS with water cooling is fabricated for high duty factor testing.

  11. Toward the Automated Generation of Components from Existing Source Code

    SciTech Connect

    Quinlan, D; Yi, Q; Kumfert, G; Epperly, T; Dahlgren, T; Schordan, M; White, B

    2004-12-02

    A major challenge to achieving widespread use of software component technology in scientific computing is an effective migration strategy for existing, or legacy, source code. This paper describes initial work and challenges in automating the identification and generation of components using the ROSE compiler infrastructure and the Babel language interoperability tool. Babel enables calling interfaces expressed in the Scientific Interface Definition Language (SIDL) to be implemented in, and called from, an arbitrary combination of supported languages. ROSE is used to build specialized source-to-source translators that (1) extract a SIDL interface specification from information implicit in existing C++ source code and (2) transform Babel's output to include dispatches to the legacy code.

  12. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect

    R.K. Johnson

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor “boosted heat pump” technology. The Low Temperature Heat Pump system operates with four increasing levels of capacity (heat output) as the outdoor temperature drops.

  13. Numerical investigation of entropy generation in microchannels heat sink with different shapes

    NASA Astrophysics Data System (ADS)

    Alfaryjat, A. A.; Stanciu, D.; Dobrovicescu, A.; Badescu, V.; Aldhaidhawi, M.

    2016-08-01

    Entropy generation of 3D cross sections circular, square, and hexagon shapes microchannel heat sinks (MCHS) were numerically performed. The governing equations (continuity, momentum and energy) along with the boundary conditions and the study state conjugate heat transfer problem were solved using the finite volume method (FVM). The Reynolds number in the range of 100 to 1600 and heat flux of 125, 150, 175 and 200 kW/m2 were covered in this study. The overall entropy generation rate and entropy generation number are obtained by integrating the volumetric rate components over the entire heat sink. The results indicated that entropy generation decreases with increases of the Reynolds number. Decreasing the heat flux led to decreasing entropy generation. The square microchannel heat sink has the lowest entropy generation and entropy generation number

  14. Comparison on welding mode characteristics of arc heat source for heat input control in hybrid welding of aluminum alloy

    NASA Astrophysics Data System (ADS)

    Song, Moo-Keun; Kim, Jong-Do; Oh, Jae-Hwan

    2015-03-01

    Presently in shipbuilding, transportation and aerospace industries, the potential to apply welding using laser and laser-arc hybrid heat sources is widely under research. This study has the purpose of comparing the weldability depending on the arc mode by varying the welding modes of arc heat sources in applying laser-arc hybrid welding to aluminum alloy and of implementing efficient hybrid welding while controlling heat input. In the experimental study, we found that hybrid welding using CMT mode produced deeper penetration and sounder bead surface than those characteristics produced during only laser welding, with less heat input compared to that required in pulsed arc mode.

  15. Perpendicular heating of electrons by upper hybrid waves generated by a ring distribution

    NASA Technical Reports Server (NTRS)

    Lin, C. S.; Menietti, J. D.; Wong, H. K.

    1990-01-01

    Satellite observations of electron conical distributions with enhanced fluxes just outside the loss cone suggest that telectrons have been heated perpendicularly to the magnetic field in the mid-altitude polar magnetosphere. To understand electron conical distributions, plasma simulations are conducted to examine an upper hybrid wave instability of a ring electron distribution perpendicular to the magnetic field in a cold electron background. The simulations indicate that both the cold and ring distributions are heated perpendicularly during the saturation stage. From the plasma data, a ring distribution can be identified as a trapped distribution function with an enhancement near 90-deg pitch angle in the phase space density plot. It is suggested that the ring distribution might provide an additional free energy source for generating upper hybrid waves associated with electron conical events.

  16. Cogeneration technology alternatives study. Volume 4: Heat Sources, balance of plant and auxiliary systems

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Data and information established for heat sources balance of plant items, thermal energy storage, and heat pumps are presented. Design case descriptions are given along with projected performance values. Capital cost estimates for representative cogeneration plants are also presented.

  17. Open Source Next Generation Visualization Software for Interplanetary Missions

    NASA Technical Reports Server (NTRS)

    Trimble, Jay; Rinker, George

    2016-01-01

    Mission control is evolving quickly, driven by the requirements of new missions, and enabled by modern computing capabilities. Distributed operations, access to data anywhere, data visualization for spacecraft analysis that spans multiple data sources, flexible reconfiguration to support multiple missions, and operator use cases, are driving the need for new capabilities. NASA's Advanced Multi-Mission Operations System (AMMOS), Ames Research Center (ARC) and the Jet Propulsion Laboratory (JPL) are collaborating to build a new generation of mission operations software for visualization, to enable mission control anywhere, on the desktop, tablet and phone. The software is built on an open source platform that is open for contributions (http://nasa.github.io/openmct).

  18. Loop Heat Pipe Transient Behavior Using Heat Source Temperature for Set Point Control with Thermoelectric Converter on Reservoir

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Paiva, Kleber; Mantelli, Marcia

    2011-01-01

    The LHP operating temperature is governed by the saturation temperature of its reservoir. Controlling the reservoir saturation temperature is commonly done by cold biasing the reservoir and using electrical heaters to provide the required control power. With this method, the loop operating temperature can be controlled within 0.5K or better. However, because the thermal resistance that exists between the heat source and the LHP evaporator, the heat source temperature will vary with its heat output even if the LHP operating temperature is kept constant. Since maintaining a constant heat source temperature is of most interest, a question often raised is whether the heat source temperature can be used for LHP set point temperature control. A test program with a miniature LHP was carried out to investigate the effects on the LHP operation when the control temperature sensor was placed on the heat source instead of the reservoir. In these tests, the LHP reservoir was cold-biased and was heated by a control heater. Test results show that it was feasible to use the heat source temperature for feedback control of the LHP operation. In particular, when a thermoelectric converter was used as the reservoir control heater, the heat source temperature could be maintained within a tight range using a proportional-integral-derivative or on/off control algorithm. Moreover, because the TEC could provide both heating and cooling to the reservoir, temperature oscillations during fast transients such as loop startup could be eliminated or substantially reduced when compared to using an electrical heater as the control heater.

  19. Heat generation and stability of a plasmonic nanogold system

    NASA Astrophysics Data System (ADS)

    Ni, Yuan; Kan, Caixia; Gao, Qi; Wei, Jingjing; Xu, Haiying; Wang, Changshun

    2016-02-01

    The surface plasmon resonance (SPR) of Au nanostructures can be precisely tuned in the visible to near-infrared (vis-NIR) region with the size and morphology. The photothermal effect induced by the SPR can raise the temperature of Au nanostructures and the surrounding matrix under external illumination. In this work, hollow Au nanostructures such as nanoboxes and nanorings with a tunable SPR in the region of 650-1100 nm were obtained by a replacement reaction between HAuCl4 and the as-prepared Ag nanostructures as the sacrificed templates. Compared with the solid Au nanorods, studies on the photothermal conversion and stability of hollow Au nanostructures were systematically carried out with the assistance of the near-infrared (NIR) lasers available. Under NIR laser irradiation, the temperatures of the colloidal Au nanostructures increased rapidly from ~30 °C to ~65 °C. Combining the experimental results with a finite-different time-domain (FDTD) numerical simulation, the heat generation of different Au nanostructures was investigated. With the consideration of the concentration of the Au nanostructures, it is indicated that hollow Au nanostructures are superior to solid Au nanorods in photothermal conversion. On increasing the NIR laser power (3 W), Au nanorods undergo a shape deformation from nanorods to spherical nanoparticles, while the SPR and morphology of hollow Au nanoboxes and nanorings maintain high stability, promising to be candidates for nanoheaters. This work provides a standard to design optimized plasmonic nanoheaters.

  20. Field Test of High Efficiency Residential Buildings with Ground-source and Air-source Heat Pump Systems

    SciTech Connect

    Ally, Moonis Raza; Munk, Jeffrey D; Baxter, Van D

    2011-01-01

    This paper describes the field performance of space conditioning and water heating equipment in four single-family residential structures with advanced thermal envelopes. Each structure features a different, advanced thermal envelope design: structural insulated panel (SIP); optimum value framing (OVF); insulation with embedded phase change materials (PCM) for thermal storage; and exterior insulation finish system (EIFS). Three of the homes feature ground-source heat pumps (GSHPs) for space conditioning and water heating while the fourth has a two-capacity air-source heat pump (ASHP) and a heat pump water heater (HPWH). Two of the GCHP-equipped homes feature horizontal ground heat exchange (GHX) loops that utillize the existing foundation and utility service trenches while the third features a vertical borehole with vertical u-tube GHX. All of the houses were operated under the same simulated occupancy conditions. Operational data on the house HVAC/Water heating (WH) systems are presented and factors influencing overall performance are summarized.

  1. Electron Beam Collimation for the Next Generation Light Source

    SciTech Connect

    Steier, C.; Emma, P.; Nishimura, H.; Papadopoulos, C.; Sannibale, F.

    2013-05-20

    The Next Generation Light Source will deliver high (MHz) repetition rate electron beams to an array of free electron lasers. Because of the significant average current in such a facility, effective beam collimation is extremely important to minimize radiation damage to undulators, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the early conceptual design of a collimation system, as well as initial results of simulations to test its effectiveness.

  2. Skutterudite Thermoelectric Generator for Electrical Power Generation from Automotive Waste Heat

    NASA Astrophysics Data System (ADS)

    Meisner, Gregory

    2012-02-01

    Filled skutterudites are state-of-the- art thermoelectric (TE) materials for electrical power generation from waste heat. They have suitable intrinsic transport properties as measured by the thermoelectric figure of merit ZT = S^2σT/κ (S = Seebeck coefficient, σ = electrical conductivity, T = temperature, and κ = thermal conductivity) and good mechanical strength for operation at vehicle exhaust gas temperatures of >550 C. We have demonstrated TE electrical power generation on a production test vehicle equipped with a fully functional prototype TE generator (TEG). It was assembled with TE modules fabricated from filled skutterudites synthesized at GM. Our results and analysis show that improvement in total power generated can be achieved by enhanced thermal and electrical interfaces and contacts. A substantial T decrease along the exhaust gas flow results in a large variation of voltage, current, and power output for each TE module depending on its position in the module array. Total TEG output power depends directly on the position-dependent T profile via the temperature dependence of both ZT and Carnot efficiency. Total TEG power output also depends on how the modules are connected in parallel or series combinations because mismatch in output voltage and/or internal resistance among the modules degrades the performance of the entire array. Uniform T profiles and consistent TE module internal resistances improve overall TEG performance.

  3. JLab CW Cryomodules for 4th Generation Light Sources

    SciTech Connect

    Rimmer, Robert; Bundy, Richard; Cheng, Guangfeng; Ciovati, Gianluigi; Clemens, William; Daly, Edward; Henry, James; Hicks, William; Kneisel, Peter; Manning, Stephen; Manus, Robert; Marhauser, Frank; Preble, Joseph; Reece, Charles; Smith, Karl; Stirbet, Mircea; Turlington, Larry; Wang, Haipeng; Wilson, Katherine

    2008-01-23

    Fourth generation light sources hold the prospect of unprecedented brightness and optical beam quality for a wide range of scientific applications. Many of the proposed new facilities will rely on large superconducting radio frequency (SRF) based linacs to provide high energy, low emittance CW electron beams. For high average power applications there is a growing acceptance of energy recovery linac (ERL) technology as the way to support large recirculating currents with modest RF power requirements. CW SRF and high current ERLs are two core competencies at Jefferson Lab. JLab has designed and built a number of CW cryomodules of several different types starting with the original CEBAF design, with variations for higher current in the two generations of JLab’s free-electron laser (FEL), through two intermediate prototypes to the final high-performance module for the 12 GeV upgrade. Each of these represent fully engineered and tested configurations with a variety of specifications that could be considered for possible use in fourth generation light sources. Furthermore JLab has been actively pursuing advanced concepts for highcurrent high-efficiency cryomodules for next generation ERL based FEL’s. These existing and proposed designs span the range from about 1mA single-pass to over 100 mA energy recovered current capability. Specialized configurations also exist for high-current non-energy recovered sections such as the injector region where very high RF power is required. We discuss the performance parameters of these existing and proposed designs and their suitability to different classes of fourth generation light sources.

  4. The MHD disk generator as a multimegawatt power supply operating with chemical and nuclear sources

    NASA Astrophysics Data System (ADS)

    Louis, J. F.

    The characteristics, performance and status of the MHD disk generator are reviewed as a potential multimegawatt power supply working with both chemical and nuclear sources. The disk generator is found to be a compact high interaction power unit with simple construction simple power conditioning and using a circular superconducting coil. The radial flow of the disk assures zero thrust in open loop operation and its construction simplicity may provide significant reliability and weight advantages. The disk generator can be operated as a high voltage, low current power supply. Experiments have shown the disk generator as high power (900 kW), high power density (500 MW/cu cm), high enthalpy extraction (15%) device which has been operated with electrical fields up to 37 kV/m. The disk generator can be operated in an open loop with either chemical or nuclear heat sources. In a closed cycle system, the disk generator can be used in a Braylon cycle using He working fluid and in a Rankin cycle using either potassium or lithium vapors as working fluid. In both cases, the generator operates in the non-equilibrium mode.

  5. Environmental assessment for the relocation and storage of isotopic heat sources, Hanford Site, Richland, Washington

    SciTech Connect

    1997-06-01

    As part of a bilateral agreement between the Federal Minister for Research and Technology of the Federal Republic of Germany (FRG) and the DOE, Pacific Northwest National Laboratory (PNNL) developed processes for the treatment and immobilization of high-level radioactive waste. One element of this bilateral agreement was the production of sealed isotopic heat sources. During the mid-1980s, 30 sealed isotopic heat sources were manufactured. The sources contain a total of approximately 8.3 million curies consisting predominantly of cesium-137 and strontium-90 with trace amounts of transuranic contamination. Currently, the sources are stored in A-Cell of the 324 Building. Intense radiation fields from the sources are causing the cell windows and equipment to deteriorate. Originally, it was not intended to store the isotopic heat sources for this length of time in A-cell. The 34 isotopic heat sources are classified as remote handled transuranic wastes. Thirty-one of the isotopic heat sources are sealed, and seals on the three remaining isotopic heat sources have not been verified. However, a decision has been made to place the remaining three isotopic heat sources in the CASTOR cask(s). The Washington State Department of Health (WDOH) has concurred that isotopic heat sources with verified seals or those placed into CASTOR cask(s) can be considered sealed (no potential to emit radioactive air emissions) and are exempt from WAC Chapter 246-247, Radiation Protection-Air Emissions.

  6. Prospects for Next-Generation Storage Ring Light Sources

    NASA Astrophysics Data System (ADS)

    Borland, Michael

    2015-04-01

    Storage ring light sources are among the most productive large-scale scientific user facilities in existence, owing to a combination of broad tunability, mature technology, high capacity, remarkable reliability, and high performance. The most commonly-used performance measure is the photon beam brightness, which is proportional to the flux per unit volume in six-dimensional phase space. The brightness is generally maximized by minimizing the transverse phase space area, or emittance, of the electron beam that generates the photons. Since the 1990's, most storage ring light sources have used a variant of the Chasman-Green, or double-bend-achromat (DBA), lattice, which produces transverse emittances of several nanometers. Presently, several light sources are under construction based on more challenging multi-bend-achromat (MBA) concepts, which promise an order of magnitude reduction in the emittance. Somewhat larger reductions are contemplated for upgrades of the largest facilities. This talk briefly surveys the relevant concepts in light source design, then explains both the mechanism and challenge of achieving next-generation emittances. Other factors, such as improved radiation-emitting devices, are also described. Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.

  7. A proposal for a novel H ion source based on electron cyclotron resonance heating and surface ionization

    SciTech Connect

    Tarvainen, Ollie A; Kurennoy, Sergey

    2008-01-01

    A design for a novel H{sup -} ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE{sub 111} eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H{sup -} ion beam is further 'self-extracted' through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H{sup -} ion current, beam emittance and duty factor of the novel source are estimated.

  8. A Proposal for a Novel H- Ion Source Based on Electron Cyclotron Resonance Plasma Heating and Surface Ionization

    NASA Astrophysics Data System (ADS)

    Tarvainen, O.; Kurennoy, S.

    2009-03-01

    A design for a novel H- ion source based on electron cyclotron resonance plasma heating and surface ionization is presented. The plasma chamber of the source is an rf-cavity designed for TE111 eigenmode at 2.45 GHz. The desired mode is excited with a loop antenna. The ionization process takes place on a cesiated surface of a biased converter electrode. The H- ion beam is further "self-extracted" through the plasma region. The magnetic field of the source is optimized for plasma generation by electron cyclotron resonance heating, and beam extraction. The design features of the source are discussed in detail and the attainable H- ion current, beam emittance and duty factor of the novel source are estimated.

  9. Hydrodynamic performance and heat generation by centrifugal pumps.

    PubMed

    Ganushchak, Y; van Marken Lichtenbelt, W; van der Nagel, T; de Jong, D S

    2006-11-01

    For over a century, centrifugal pumps (CP) have been used in various applications, from large industrial pumps to flow pumps for aquariums. However, the use of CP as blood pumps has a rather short history. Consequently, the hydraulic performance data for a blood CP are limited. The aim of our investigation was to study the hydraulic performance and the heat generation of three commercially available CP: Bio-Medicus Bio-Pump BP80 (Medtronic), Rotaflow (Jostra Medizintechnik), and DeltaStream DP2 (MEDOS Medizintechnik AQ). The study was performed using a circuit primed with a water-glycerin mixture with a dynamic viscosity of 0.00272 pa/s. Pressure-flow curves were obtained by a stepwise stagnation of the pump outlet or inlet. The temperature changes were observed using ThermaCAM SC2000 (Flir Systems). The pumps' performance in close to clinical conditions ('operating region') was analysed in this report. The 'operating region' in the case of the BP80 is positioned around the pressure-flow curve at a pump speed of 3000 rpm. In the case of the Rotaflow, the 'operating region' was between the pump pressure-flow curves at a speed of 3000 and 4000 rpm, and the DP2 was found between 7000 and 8000 rpm. The standard deviation of mean pressure through the pump was used to characterise the stability of the pump. In experiments with outlet stagnation, the BP80 demonstrated high negative association between flow and pressure variability (r = -0.68, p < 0.001). In experiments with the DP2, this association was positive (r = 0.68, p < 0.001). All pumps demonstrated significantly higher variability of pressure in experiments with inlet stagnation in comparison to the experiments with outlet stagnation. The rise of relative temperature in the inlet of a pump was closely related to the flow rate. The heating of fluid was more pronounced in the 'zero-flow' mode, especially in experiments with inlet stagnation. In summary, (1) the 'zero-flow' regime, which is described in the manuals

  10. Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source.

    PubMed

    Castro, G; Mascali, D; Romano, F P; Celona, L; Gammino, S; Lanaia, D; Di Giugno, R; Miracoli, R; Serafino, T; Di Bartolo, F; Gambino, N; Ciavola, G

    2012-02-01

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating. PMID:22380300

  11. Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source

    SciTech Connect

    Castro, G.; Di Giugno, R.; Miracoli, R.; Mascali, D.; Romano, F. P.; Celona, L.; Gammino, S.; Lanaia, D.; Ciavola, G.; Serafino, T.; Di Bartolo, F.; Gambino, N.

    2012-02-15

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating.

  12. Comparison between off-resonance and electron Bernstein waves heating regime in a microwave discharge ion source.

    PubMed

    Castro, G; Mascali, D; Romano, F P; Celona, L; Gammino, S; Lanaia, D; Di Giugno, R; Miracoli, R; Serafino, T; Di Bartolo, F; Gambino, N; Ciavola, G

    2012-02-01

    A microwave discharge ion source (MDIS) operating at the Laboratori Nazionali del Sud of INFN, Catania has been used to compare the traditional electron cyclotron resonance (ECR) heating with an innovative mechanisms of plasma ignition based on the electrostatic Bernstein waves (EBW). EBW are obtained via the inner plasma electromagnetic-to-electrostatic wave conversion and they are absorbed by the plasma at cyclotron resonance harmonics. The heating of plasma by means of EBW at particular frequencies enabled us to reach densities much larger than the cutoff ones. Evidences of EBW generation and absorption together with X-ray emissions due to high energy electrons will be shown. A characterization of the discharge heating process in MDISs as a generalization of the ECR heating mechanism by means of ray tracing will be shown in order to highlight the fundamental physical differences between ECR and EBW heating.

  13. Explosion overpressure test series: General-Purpose Heat Source development: Safety Verification Test program

    SciTech Connect

    Cull, T.A.; George, T.G.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular, radioisotope heat source that will be used in radioisotope thermoelectric generators (RTGs) to supply electric power for space missions. The first two uses will be the NASA Galileo and the ESA Ulysses missions. The RTG for these missions will contain 18 GPHS modules, each of which contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) was conducted to assess the ability of the GPHS modules to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System vehicle (space shuttle) is a conceivable accident, the SVT plan included a series of tests that simulated the overpressure exposure the RTG and GPHS modules could experience in such an event. Results of these tests, in which we used depleted UO/sub 2/ as a fuel simulant, suggest that exposure to overpressures as high as 15.2 MPa (2200 psi), without subsequent impact, does not result in a release of fuel.

  14. High efficiency, quasi-instantaneous steam expansion device utilizing fossil or nuclear fuel as the heat source

    SciTech Connect

    Claudio Filippone, Ph.D.

    1999-06-01

    Thermal-hydraulic analysis of a specially designed steam expansion device (heat cavity) was performed to prove the feasibility of steam expansions at elevated rates for power generation with higher efficiency. The steam expansion process inside the heat cavity greatly depends on the gap within which the steam expands and accelerates. This system can be seen as a miniaturized boiler integrated inside the expander where steam (or the proper fluid) is generated almost instantaneously prior to its expansion in the work-producing unit. Relatively cold water is pulsed inside the heat cavity, where the heat transferred causes the water to flash to steam, thereby increasing its specific volume by a large factor. The gap inside the heat cavity forms a special nozzle-shaped system in which the fluid expands rapidly, accelerating toward the system outlet. The expansion phenomenon is the cause of ever-increasing fluid speed inside the cavity system, eliminating the need for moving parts (pumps, valves, etc.). In fact, the subsequent velocity induced by the sudden fluid expansion causes turbulent conditions, forcing accelerating Reynolds and Nusselt numbers which, in turn, increase the convective heat transfer coefficient. When the combustion of fossil fuels constitutes the heat source, the heat cavity concept can be applied directly inside the stator of conventional turbines, thereby greatly increasing the overall system efficiency.

  15. Constraining high-redshift X-ray sources with next generation 21-cm power spectrum measurements

    NASA Astrophysics Data System (ADS)

    Ewall-Wice, Aaron; Hewitt, Jacqueline; Mesinger, Andrei; Dillon, Joshua S.; Liu, Adrian; Pober, Jonathan

    2016-05-01

    We use the Fisher matrix formalism and seminumerical simulations to derive quantitative predictions of the constraints that power spectrum measurements on next-generation interferometers, such as the Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometre Array (SKA), will place on the characteristics of the X-ray sources that heated the high-redshift intergalactic medium. Incorporating observations between z = 5 and 25, we find that the proposed 331 element HERA and SKA phase 1 will be capable of placing ≲ 10 per cent constraints on the spectral properties of these first X-ray sources, even if one is unable to perform measurements within the foreground contaminated `wedge' or the FM band. When accounting for the enhancement in power spectrum amplitude from spin temperature fluctuations, we find that the observable signatures of reionization extend well beyond the peak in the power spectrum usually associated with it. We also find that lower redshift degeneracies between the signatures of heating and reionization physics lead to errors on reionization parameters that are significantly greater than previously predicted. Observations over the heating epoch are able to break these degeneracies and improve our constraints considerably. For these two reasons, 21-cm observations during the heating epoch significantly enhance our understanding of reionization as well.

  16. Multifunctional Porous Graphene for High-Efficiency Steam Generation by Heat Localization.

    PubMed

    Ito, Yoshikazu; Tanabe, Yoichi; Han, Jiuhui; Fujita, Takeshi; Tanigaki, Katsumi; Chen, Mingwei

    2015-08-01

    Multifunctional nanoporous graphene is realized as a heat generator to convert solar illumination into high-energy steam. The novel 3D nanoporous graphene demonstrates a highly energy-effective steam generation with an energy conversation of 80%.

  17. Multifunctional Porous Graphene for High-Efficiency Steam Generation by Heat Localization.

    PubMed

    Ito, Yoshikazu; Tanabe, Yoichi; Han, Jiuhui; Fujita, Takeshi; Tanigaki, Katsumi; Chen, Mingwei

    2015-08-01

    Multifunctional nanoporous graphene is realized as a heat generator to convert solar illumination into high-energy steam. The novel 3D nanoporous graphene demonstrates a highly energy-effective steam generation with an energy conversation of 80%. PMID:26079440

  18. From Modules to a Generator: An Integrated Heat Exchanger Concept for Car Applications of a Thermoelectric Generator

    NASA Astrophysics Data System (ADS)

    Bosch, Henry

    2016-03-01

    A heat exchanger concept for a thermoelectric generator with integrated planar modules for passenger car applications is introduced. The module housings, made of deep drawn stainless steel sheet metal, are brazed onto the exhaust gas channel to achieve an optimal heat transfer on the hot side of the modules. The cooling side consists of winding fluid channels, which are mounted directly onto the cold side of the modules. Only a thin foil separates the cooling media from the modules for an almost direct heat contact on the cooling side. Thermoelectric generators with up to 20 modules made of PbTe and Bi2Te3, respectively, are manufactured and tested on a hot gas generator to investigate electrical power output and performance of the thermoelectric generator. The proof of concept of the light weight heat exchanger design made of sheet metal with integrated modules is positively accomplished.

  19. Documentation generator application for MatLab source codes

    NASA Astrophysics Data System (ADS)

    Niton, B.; Pozniak, K. T.; Romaniuk, R. S.

    2011-06-01

    The UML, which is a complex system modeling and description technology, has recently been expanding its uses in the field of formalization and algorithmic approach to such systems like multiprocessor photonic, optoelectronic and advanced electronics carriers; distributed, multichannel measurement systems; optical networks, industrial electronics, novel R&D solutions. The paper describes a realization of an application for documenting MatLab source codes. There are presented own novel solution based on Doxygen program which is available on the free license, with accessible source code. The used supporting tools for parser building were Bison and Flex. There are presented the practical results of the documentation generator. The program was applied for exemplary MatLab codes. The documentation generator application is used for design of large optoelectronic and electronic measurement and control systems. The paper consists of three parts which describe the following components of the documentation generator for photonic and electronic systems: concept, MatLab application and VHDL application. This is part two which describes the MatLab application. MatLab is used for description of the measured phenomena.

  20. Harvesting Nanocatalytic Heat Localized in Nanoalloy Catalyst as a Heat Source in a Nanocomposite Thin Film Thermoelectric Device.

    PubMed

    Zhao, Wei; Shan, Shiyao; Luo, Jin; Mott, Derrick M; Maenosono, Shinya; Zhong, Chuan-Jian

    2015-10-20

    This report describes findings of an investigation of harvesting nanocatalytic heat localized in a nanoalloy catalyst layer as a heat source in a nanocomposite thin film thermoelectric device for thermoelectric energy conversion. This device couples a heterostructured copper-zinc sulfide nanocomposite for thermoelectrics and low-temperature combustion of methanol fuels over a platinum-cobalt nanoalloy catalyst for producing heat localized in the nanocatalyst layer. The possibility of tuning nanocatalytic heat in the nanocatalyst and thin film thermoelectric properties by compositions points to a promising pathway in thermoelectric energy conversion.

  1. Harvesting Nanocatalytic Heat Localized in Nanoalloy Catalyst as a Heat Source in a Nanocomposite Thin Film Thermoelectric Device.

    PubMed

    Zhao, Wei; Shan, Shiyao; Luo, Jin; Mott, Derrick M; Maenosono, Shinya; Zhong, Chuan-Jian

    2015-10-20

    This report describes findings of an investigation of harvesting nanocatalytic heat localized in a nanoalloy catalyst layer as a heat source in a nanocomposite thin film thermoelectric device for thermoelectric energy conversion. This device couples a heterostructured copper-zinc sulfide nanocomposite for thermoelectrics and low-temperature combustion of methanol fuels over a platinum-cobalt nanoalloy catalyst for producing heat localized in the nanocatalyst layer. The possibility of tuning nanocatalytic heat in the nanocatalyst and thin film thermoelectric properties by compositions points to a promising pathway in thermoelectric energy conversion. PMID:26444621

  2. A multilevel voltage-source inverter with separate dc sources for static var generation

    SciTech Connect

    Peng, Fang Zheng |; Lai, Jih-Sheng; McKeever, J.; VanCoevering, J.

    1995-09-01

    A new multilevel voltage-source inverter with a separate dc sources is proposed for high-voltage, high-power applications, such as flexible ac transmission systems (FACTS) including static var generation (SVG), power line conditioning, series compensation, phase shifting, voltage balancing, fuel cell and photovoltaic utility systems interfacing, etc. The new M-level inverter consists of (M-1)/2 single phase full bridges in which each bridge has its own separate dc source. This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle as the number of levels increases. It can solve the problems of conventional transformer-based multipulse inverters and the problems of the multilevel diode-clamped inverter and the multilevel flying capacitor inverter. To demonstrate the superiority of the new inverter, a SVG system using the new inverter topology is discussed through analysis, simulation and experiment.

  3. Monolithic fuel cell based power source for burst power generation

    NASA Astrophysics Data System (ADS)

    Fee, D. C.; Blackburn, P. E.; Busch, D. E.; Dees, D. W.; Dusek, J.; Easler, T. E.; Ellingson, W. A.; Flandermeyer, B. K.; Fousek, R. J.; Heiberger, J. J.

    A unique fuel cell coupled with a low power nuclear reactor presents an attractive approach for SDI burst power requirements. The monolithic fuel cell looks attractive for space applications and represents a quantum jump in fuel cell technology. Such a breakthrough in design is the enabling technology for lightweight, low volume power sources for space based pulse power systems. The monolith is unique among fuel cells in being an all solid state device. The capability for miniaturization, inherent in solid state devices, gives the low volume required for space missions. In addition, the solid oxide fuel cell technology employed in the monolith has high temperature reject heat and can be operated in either closed or open cycles. Both these features are attractive for integration into a burst power system.

  4. Electricity-producing heating apparatus utilizing a turbine generator in a semi-closed brayton cycle

    DOEpatents

    Labinov, Solomon D.; Christian, Jeffrey E.

    2003-10-07

    The present invention provides apparatus and methods for producing both heat and electrical energy by burning fuels in a stove or boiler using a novel arrangement of a surface heat exchanger and microturbine-powered generator and novel surface heat exchanger. The equipment is particularly suited for use in rural and relatively undeveloped areas, especially in cold regions and highlands.

  5. Generator-Absorber heat exchange transfer apparatus and method using an intermediate liquor

    DOEpatents

    Phillips, Benjamin A.; Zawacki, Thomas S.

    1996-11-05

    Numerous embodiments and related methods for generator-absorber heat exchange (GAX) are disclosed, particularly for absorption heat pump systems. Such embodiments and related methods use the working solution of the absorption system for the heat transfer medium where the working solution has an intermediate liquor concentration.

  6. Coherent nuclear resonant optics for third generation synchrotron radiation sources

    SciTech Connect

    Alp, E.E.; Mooney, T.M.; Toellner, T.; Homma, H.; Kentjana, M.

    1992-06-01

    The insertion-device-based, third-generation, synchrotron radiation sources now under construction in Europe, the USA, and Japan bring new opportunities and challenges in the design and manufacture of x-ray optics. These high brightness sources provide new opportunities to overcome some of the outstanding problems associated with nuclear resonant monochromatization of synchrotron radiation. New methods such as polarizing monochromators, and zone plates provide alternative methods for production of {mu}eV-neV resolution in the hard x-ray regime. The design principles, and characterization, and performance of crystal monochromators and of nuclear coherent scattering optics, including Grazing Incidence Anti Reflection (GIAR) films, multilayers, zone plates, as well as single crystals are discussed.

  7. Multilayers for next generation x-ray sources

    SciTech Connect

    Bajt, S; Chapman, H N; Spiller, E; Hau-Riege, S; Alameda, J; Nelson, A J; Walton, C C; Kjornrattanawanich, B; Aquila, A; Dollar, F; Gullikson, E; Tarrio, C

    2007-05-04

    Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.

  8. Reentry thermal testing of a general purpose heat source fueled clad

    SciTech Connect

    Peterson, D.E.; Frantz, C.E.

    1982-03-01

    A General Purpose Heat Source (GPHS) module was exposed to heat treatments simulating an isothermal prelaunch condition, followed by thermal pulses corresponding to atmospheric reentry. Helium release rates were determined during each heating and modeled after simple diffusion theory. Following the tests, the module was examined metallurgically with no evidence of swelling of the cladding nor degradation of the fuel.

  9. Handling radiation generated during an ion source commissioning

    SciTech Connect

    Ren, H. T.; Zhao, J. Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Xu, Y.; Chen, J.; Zhang, T.; Zhang, A. L.; Guo, Z. Y.; Chen, J. E.

    2014-02-15

    Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H{sup +} ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D{sup +} beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.

  10. Handling radiation generated during an ion source commissioning

    NASA Astrophysics Data System (ADS)

    Ren, H. T.; Zhao, J.; Peng, S. X.; Lu, P. N.; Zhou, Q. F.; Xu, Y.; Chen, J.; Zhang, T.; Zhang, A. L.; Guo, Z. Y.; Chen, J. E.

    2014-02-01

    Radiation is an important issue, which should be carefully treated during the design and commissioning of an ion source. Measurements show that X-rays are generated around the ceramics column of an extraction system when the source is powered up to 30 kV. The X-ray dose increases greatly when a beam is extracted. Inserting the ceramic column into a metal vacuum box is a good way to block X-ray emission for those cases. Moreover, this makes the online test of an intense H+ ion beam with energy up to 100 keV possible. However, for deuteron ion source commissioning, neutron and gamma-ray radiation become a serious topic. In this paper, we will describe the design of the extraction system and the radiation doses of neutrons and gamma-rays measured at different D+ beam energy during our 2.45 GHz deuteron electron cyclotron resonance ion source commissioning for PKUNIFTY (PeKing University Neutron Imaging FaciliTY) project at Peking University.

  11. Metrology laboratory requirements for third-generation synchrotron radiation sources

    SciTech Connect

    Takacs, P.Z.; Quian, Shinan

    1997-11-01

    New third-generation synchrotron radiation sources that are now, or will soon, come on line will need to decide how to handle the testing of optical components delivered for use in their beam lines. In many cases it is desirable to establish an in-house metrology laboratory to do the work. We review the history behind the formation of the Optical Metrology Laboratory at Brookhaven National Laboratory and the rationale for its continued existence. We offer suggestions to those who may be contemplating setting up similar facilities, based on our experiences over the past two decades.

  12. Scale/Analytical Analyses of Freezing and Convective Melting with Internal Heat Generation

    SciTech Connect

    Ali S. Siahpush; John Crepeau; Piyush Sabharwall

    2013-07-01

    Using a scale/analytical analysis approach, we model phase change (melting) for pure materials which generate constant internal heat generation for small Stefan numbers (approximately one). The analysis considers conduction in the solid phase and natural convection, driven by internal heat generation, in the liquid regime. The model is applied for a constant surface temperature boundary condition where the melting temperature is greater than the surface temperature in a cylindrical geometry. The analysis also consider constant heat flux (in a cylindrical geometry).We show the time scales in which conduction and convection heat transfer dominate.

  13. Designing, selecting and installing a residential ground-source heat pump system

    SciTech Connect

    Hughes, Patrick; Liu, Xiaobing; Munk, Jeffrey D

    2010-01-01

    It's a compelling proposition: Use the near-constant-temperature heat underground to heat and cool your home and heat domestic water, slashing your energy bills. Yet despite studies demonstrating significant energy savings from ground-source heat pump (GSHP) systems, their adoption has been hindered by high upfront costs. Fewer than 1% of US homes use a GSHP system. However, compared to a minimum-code-compliant conventional space-conditioning system, when properly designed and installed, a GSHP retrofit at current market prices offers simple payback of 4.3 years on national average, considering existing federal tax credits. Most people understand how air-source heat pumps work: they move heat from indoor air to outdoor air when cooling and from outdoor air to indoor air when heating. The ground-source heat pump operates on the same principle, except that it moves heat to or from the ground source instead of outdoor air. The ground source is usually a vertical or horiontal ground heat exchanger. Because the ground usually has a more favorable temperature than ambient air for the heating and cooling operation of the vapor-compression refrigeration cycle, GSHP sysems can operate with much higher energy efficiencies than air-source heat pump systems when properly designed and installed. A GSHP system used in a residual building typically provides space conditioning and hot water and comprises three major components: a water-source heat pump unit designed to operate at a wider range of entering fluid temperatures (typically from 30 F to 110 F, or 1 C to 43 C) than a conventional water-source heat pump unit; a ground heat exchanger (GHX); and distribution systems to deliver hot water to the storage tank and heating or cooling to the conditioned rooms. In most residual GSHP systems, the circulation pumps and associated valves are integrated with the heat pump to circulate the heat-carrier fluid (water or aqueous antifreeze solution) through the heat pump and the GHX. A

  14. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect

    Johnson, R. K.

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor 'boosted heat pump' technology. The Low Temperature Heat Pumpsystem operates with four increasing levels of capacity (heat output) as the outdoor temperature drops. The system was shown to select capacity correctly, supplying the appropriate amount of heat to the house across the full range of outdoor temperatures. The system's Coefficient of Performance (Seasonal COP, or SCOP) over two entire winters was calculated, based on measured data, to be 3.29over the first winter and 2.68 over the second winter. A second seasonal efficiency calculation by a different method yielded a SCOP of 2.78 for the first winter and 2.83 for the second winter. This second seasonal efficiency calculation was determined by comparing measured heat pump energy use to the in situ energy use with resistance heat alone. This method is the ratio of the slopes of thedaily energy use load lines.

  15. A Microfabricated Deuterium Ion Source for Compact Neutron Generators

    NASA Astrophysics Data System (ADS)

    Johnson, Benjamin Bargsten

    Active neutron interrogation is generally accepted as a reliable means of detecting the illicit transportation of special nuclear materials, in particular highly enriched uranium. The development of portable active neutron interrogation systems for field detection applications could be facilitated by the use of a new deuterium ion source which has the potential to advance many of the performance limiting aspects of exiting compact, accelerator-driven neutron generators. The ion source being investigated is a gated array of sharp metal tips that uses high electric fields to generate deuterium ion currents through the physical processes of field ionization and field desorption. The deuterium ions produced by the source are extracted and used to drive a D-D (or D-T) fusion reaction to create neutrons. The basic microstructure for the ion source array is derived from modern semiconductor microfabrication technology for field emitter arrays, though many structural modifications have been made in an attempt to reach the required operating fields of the ion generation processes. Pulsed (field desorption) and d.c. (field ionization) tests conducted with each array design type developed thus far indicate a steady improvement in array tip operating fields. Field ionization studies were conducted with arrays at source temperatures of 77 K and 293 K. Newly developed arrays have demonstrated field ionization currents upwards of ˜50 nA, which is roughly 50% of the maximum ion production possible, as presently fabricated. Neutron production by field ionization was demonstrated for the first time from the microfabricated arrays. A maximum neutron yield of 95 n/s (6300 n/s/cm2 of array active area) was observed from a 1.5 mm2 array using a D-D fusion reaction at -90 kV. Field desorption studies at 77 K and 293 K were conducted in parallel with field ionization testing. To date, the arrays have consistently demonstrated the field desorption of deuterium ions from array tip surfaces

  16. Possibilities of utilizing alternative energy sources for combined heat supply systems in the Baltic

    SciTech Connect

    Shipkovs, P.; Grislis, V.; Zebergs, V. )

    1991-01-01

    The problem of alternative energy sources is an issue of major importance for the Baltic republics because of the limited supply of conventional energy resources. One of the ways to solve this problem could be the introduction of combined heat supply systems (CHSS). The combined heat supply systems are such systems where various energy sources in different regimes are made use of to ensure the optimum temperature on residential and industrial premises. The influence of climatic conditions on the selection of heat supply systems has been studied at large. In the present paper the use of alternative energy sources (AES) in combined heat supply systems (CHSS) is described.

  17. Thermodynamic formalism of minimum heat source temperature for driving advanced adsorption cooling device

    NASA Astrophysics Data System (ADS)

    Saha, Bidyut Baran; Chakraborty, Anutosh; Koyama, Shigeru; Srinivasan, Kandadai; Ng, Kim Choon; Kashiwagi, Takao; Dutta, Pradip

    2007-09-01

    This letter presents a thermodynamic formulation to calculate the minimum driving heat source temperature of an advanced solid sorption cooling device, and it is validated with experimental data. This formalism has been developed from the rigor of the Boltzmann distribution function and the condensation approximation of adsorptive molecules. An interesting and useful finding has been established from this formalism that it is possible to construct a solid sorption refrigeration device that operates in a cycle transferring heat from a low temperature source to a heat sink with a driving heat source at a temperature close to but above ambient.

  18. A capital cost comparison of commercial ground-source heat pump systems

    SciTech Connect

    Rafferty, K.

    1995-02-01

    In the March 1994 issue of the Quarterly Bulletin, a Geo-Heat Center Research Project involving ground-source heat pumps (GSHP) systems for commercial buildings was introduced. This project which evaluated the capital costs associated with three different ground-source designs was completed in June 1994. As a result of this work, a final report {open_quotes}A Capital Cost Comparison of Commercial Ground-Source Heat Pump Systems{close_quotes} was issued. This article is a summary of that report. The full report is available from the Geo-Heat Center.

  19. Temperature and Humidity Independent Control Research on Ground Source Heat Pump Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Chen, G.; Wang, L. L.

    Taking green demonstration center building air conditioning system as an example, this paper presents the temperature and humidity independent control system combined with ground source heat pump system, emphasis on the design of dry terminal device system, fresh air system and ground source heat pump system.

  20. Optimum load distribution between heat sources based on the Cournot model

    NASA Astrophysics Data System (ADS)

    Penkovskii, A. V.; Stennikov, V. A.; Khamisov, O. V.

    2015-08-01

    One of the widespread models of the heat supply of consumers, which is represented in the "Single buyer" format, is considered. The methodological base proposed for its description and investigation presents the use of principles of the theory of games, basic propositions of microeconomics, and models and methods of the theory of hydraulic circuits. The original mathematical model of the heat supply system operating under conditions of the "Single buyer" organizational structure provides the derivation of a solution satisfying the market Nash equilibrium. The distinctive feature of the developed mathematical model is that, along with problems solved traditionally within the bounds of bilateral relations of heat energy sources-heat consumer, it considers a network component with its inherent physicotechnical properties of the heat network and business factors connected with costs of the production and transportation of heat energy. This approach gives the possibility to determine optimum levels of load of heat energy sources. These levels provide the given heat energy demand of consumers subject to the maximum profit earning of heat energy sources and the fulfillment of conditions for formation of minimum heat network costs for a specified time. The practical realization of the search of market equilibrium is considered by the example of a heat supply system with two heat energy sources operating on integrated heat networks. The mathematical approach to the solution search is represented in the graphical form and illustrates computations based on the stepwise iteration procedure for optimization of levels of loading of heat energy sources (groping procedure by Cournot) with the corresponding computation of the heat energy price for consumers.

  1. Regional trends in radiogenic heat generation in the Precambrian basement of the Western Canadian Basin

    NASA Astrophysics Data System (ADS)

    Jones, F. W.; Majorowicz, J. A.

    Radiogenic heat generation values for 381 basement samples from 229 sites in the western Canadian basin exhibit a lognormal frequency distribution. The mean value = 2.06 (S.D. = 1.22) µWm-3 is larger than the radiogenic heat generation values reported for the shield in the Superior (ca. 1.2 µWm-3, Jessop and Lewis, 1978) and Churchill (ca. 0.7 µWm-3, Drury, 1985) provinces. When equal Log A contour intervals are used to map the basement heat generation, three large zones of relatively high heat generation are found. One coincides with the Peace River Arch basement structure and one with the Athabasca axis (Darnley, 1981). There is no apparent indication of increased heat flow through the Paleozoic formations associated with these two zones. The third zone, in southwestern Saskatchewan, coincides with a high heat flow zone in the Swift Current area. The lack of correlation between heat flow and heat generation in Alberta may be due to the disturbance to the heat flow in the Paleozoic formations by water motion, or may indicate that the heat is from uranium, thorium and potassium isotope enrichment near the basement surface rather than enrichment throughout the entire upper crust.

  2. Influence of water grid on combustion process in small dendromass heat source

    NASA Astrophysics Data System (ADS)

    Papučík, Štefan; Pilát, Peter; Hrabovský, Peter; Patsch, Marek

    2016-06-01

    For achieving of low emission in compliance of required performance parameters of small heat source affects a number of factors. It's not just about redistribution and intensity of combustion air or flue gas temperature in the chimney. An important role in the combustion process also have a combustion chamber shape, size of embers, placing of the fuel in the chamber, positioning, distribution and temperature of combustion air entering into the combustion process, the tightness of the measured heat source or temperature of the combustion chamber. The bigger problem with the achievement of low emission limits occurs at the operation of gasification heat source in lower performance. The article discusses about the effects on the combustion process is simple structural adjustment of heat source - removal of water grate during operation at reduced performance. On measuring were used identical small heat sources (with and without lambda probe oxygen sensor, with water and without water grate), which uses principle of biomass gasification.

  3. Development of Electricity Generation from Renewable Energy Sources in Turkey

    NASA Astrophysics Data System (ADS)

    Kentel, E.

    2011-12-01

    Electricity is mainly produced from coal, natural gas and hydropower in Turkey. However, almost all the natural gas and high quality coal are imported. Thus, increasing the shares of both hydro and other renewables in energy supply is necessary to decrease dependency of the country on foreign sources. In 2008, the total installed capacity of Turkey was around 42000 MW and 66 % of this was from thermal sources. The remaining 33 % was from hydro, which leaves only one percent for the other renewable energy sources. The share of renewable energy in the energy budget of Turkey has increased in the last two decades; however, in 2008, only 17 % of the total electricity generation was realized from renewable sources most of which was hydro. According to State Hydraulic Works (SHW) which is the primary executive state agency responsible for the planning, operating and managing of Turkey's water resources, Turkey utilizes only around 35% of its economically viable hydro potential. The current situation clearly demonstrates the need for increasing the share of renewables in the energy budget. New laws, such as the Electricity Market Law, have been enacted and the following items were identified by the Ministry of Energy and Natural Resources of Turkey among primary energy policies and priorities: (i) decreasing dependency on foreign resources by prioritizing utilization of natural resources, (ii) increasing the share of renewable energy resources in the energy budget of Turkey; (iii) minimization of adverse environmental impacts of production and utilization of natural resources. The government's energy policy increased investments in renewable energy resources; however lack of a needed legal framework brought various environmental and social problems with this fast development. The development of the share of renewable resources in the energy budget, current government policy, and environmental concerns related with renewables, and ideas to improve the overall benefits of

  4. Quantitative Comparison of Photothermal Heat Generation between Gold Nanospheres and Nanorods

    NASA Astrophysics Data System (ADS)

    Qin, Zhenpeng; Wang, Yiru; Randrianalisoa, Jaona; Raeesi, Vahid; Chan, Warren C. W.; Lipiński, Wojciech; Bischof, John C.

    2016-07-01

    Gold nanoparticles (GNPs) are widely used for biomedical applications due to unique optical properties, established synthesis methods, and biological compatibility. Despite important applications of plasmonic heating in thermal therapy, imaging, and diagnostics, the lack of quantification in heat generation leads to difficulties in comparing the heating capability for new plasmonic nanostructures and predicting the therapeutic and diagnostic outcome. This study quantifies GNP heat generation by experimental measurements and theoretical predictions for gold nanospheres (GNS) and nanorods (GNR). Interestingly, the results show a GNP-type dependent agreement between experiment and theory. The measured heat generation of GNS matches well with theory, while the measured heat generation of GNR is only 30% of that predicted theoretically at peak absorption. This then leads to a surprising finding that the polydispersity, the deviation of nanoparticle size and shape from nominal value, significantly influences GNR heat generation (>70% reduction), while having a limited effect for GNS (<10% change). This work demonstrates that polydispersity is an important metric in quantitatively predicting plasmonic heat generation and provides a validated framework to quantitatively compare the heating capabilities between gold and other plasmonic nanostructures.

  5. Quantitative Comparison of Photothermal Heat Generation between Gold Nanospheres and Nanorods.

    PubMed

    Qin, Zhenpeng; Wang, Yiru; Randrianalisoa, Jaona; Raeesi, Vahid; Chan, Warren C W; Lipiński, Wojciech; Bischof, John C

    2016-01-01

    Gold nanoparticles (GNPs) are widely used for biomedical applications due to unique optical properties, established synthesis methods, and biological compatibility. Despite important applications of plasmonic heating in thermal therapy, imaging, and diagnostics, the lack of quantification in heat generation leads to difficulties in comparing the heating capability for new plasmonic nanostructures and predicting the therapeutic and diagnostic outcome. This study quantifies GNP heat generation by experimental measurements and theoretical predictions for gold nanospheres (GNS) and nanorods (GNR). Interestingly, the results show a GNP-type dependent agreement between experiment and theory. The measured heat generation of GNS matches well with theory, while the measured heat generation of GNR is only 30% of that predicted theoretically at peak absorption. This then leads to a surprising finding that the polydispersity, the deviation of nanoparticle size and shape from nominal value, significantly influences GNR heat generation (>70% reduction), while having a limited effect for GNS (<10% change). This work demonstrates that polydispersity is an important metric in quantitatively predicting plasmonic heat generation and provides a validated framework to quantitatively compare the heating capabilities between gold and other plasmonic nanostructures. PMID:27445172

  6. Quantitative Comparison of Photothermal Heat Generation between Gold Nanospheres and Nanorods

    PubMed Central

    Qin, Zhenpeng; Wang, Yiru; Randrianalisoa, Jaona; Raeesi, Vahid; Chan, Warren C. W.; Lipiński, Wojciech; Bischof, John C.

    2016-01-01

    Gold nanoparticles (GNPs) are widely used for biomedical applications due to unique optical properties, established synthesis methods, and biological compatibility. Despite important applications of plasmonic heating in thermal therapy, imaging, and diagnostics, the lack of quantification in heat generation leads to difficulties in comparing the heating capability for new plasmonic nanostructures and predicting the therapeutic and diagnostic outcome. This study quantifies GNP heat generation by experimental measurements and theoretical predictions for gold nanospheres (GNS) and nanorods (GNR). Interestingly, the results show a GNP-type dependent agreement between experiment and theory. The measured heat generation of GNS matches well with theory, while the measured heat generation of GNR is only 30% of that predicted theoretically at peak absorption. This then leads to a surprising finding that the polydispersity, the deviation of nanoparticle size and shape from nominal value, significantly influences GNR heat generation (>70% reduction), while having a limited effect for GNS (<10% change). This work demonstrates that polydispersity is an important metric in quantitatively predicting plasmonic heat generation and provides a validated framework to quantitatively compare the heating capabilities between gold and other plasmonic nanostructures. PMID:27445172

  7. Vapor source for thermionic converters designed from a gas-regulated two-component heat pipe

    NASA Astrophysics Data System (ADS)

    Gverdtsiteli, I. G.; Ermilov, B. I.; Kalandarishvili, A. G.; Chilingarishvili, P. D.

    1985-03-01

    Gverdtsiteli et al. (1979) have considered an adjustable heat pipe for supplying vaporized cesium. Multicomponent adjustable heat pipes are of particular interest for thermionic converters, and investigations have been conducted regarding heat pipes employing two-component mixtures as heat carrier. The present paper provides experimental results concerning a two-component gas-regulated vapor sourse for thermionic converters, taking into account the use of gas-regulated heat pipes. It is found that the output powers of thermionic converters can be regulated over a wide range by making use of Cs-Rb gas-regulated heat pipes as vapor sources.

  8. The Advanced Light Source: A third-generation Synchrotron Radiation Source

    SciTech Connect

    Robinson, Arthur L.

    2002-08-14

    The Advanced Light Source (ALS) at the E.O. Lawrence Berkeley National Laboratory (Berkeley Lab) of the University of California is a ''third-generation'' synchrotron radiation source optimized for highest brightness at ultraviolet and soft x-ray photon energies. It also provides world-class performance at hard x-ray photon energies. Berkeley Lab operates the ALS for the United States Department of Energy as a national user facility that is available 24 hours/day around the year for research by scientists from industrial, academic, and government laboratories primarily from the United States but also from abroad.

  9. Next Generation H{sup -} Ion Sources for the SNS

    SciTech Connect

    Welton, R. F.; Stockli, M. P.; Murray, S. N.; Crisp, D.; Carmichael, J.; Goulding, R. H.; Han, B.; Pennisi, T.; Santana, M.; Tarvainen, O.

    2009-03-12

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H- ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H- ion source based on an A1N ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to {approx}100 mA(60 Hz, 1 ms) have been observed and sustained currents >60 mA(60 Hz, 1 ms) have been demonstrated on the test stand. Accelerated beam currents of {approx}40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H- beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  10. Next Generation H- Ion Sources for the SNS

    SciTech Connect

    Welton, Robert F; Carmichael, Justin R; Carr, Jr, Jerry; Crisp, Danny W; Goulding, Richard Howell; Han, Baoxi; Pennisi, Terry R; Murray Jr, S N; Stockli, Martin P; Tarvainen, Olli A; Santana, Manuel

    2009-01-01

    The U.S. Spallation Neutron Source (SNS) is the leading accelerator-based, pulsed neutron-scattering facility, currently in the process of ramping up neutron production. In order to insure meeting operational requirements as well as providing for future facility beam power upgrades, a multifaceted H{sup -} ion source development program is ongoing. This work discusses several aspects of this program, specifically the design and first beam measurements of an RF-driven, external antenna H{sup -} ion source based on an AlN ceramic plasma chamber, elemental and chromate Cs-systems, and plasma ignition gun. Unanalyzed beam currents of up to {approx}100 mA (60Hz, 1ms) have been observed and sustained currents >60 mA (60Hz, 1ms) have been demonstrated on the test stand. Accelerated beam currents of {approx}40 mA have also been demonstrated into the SNS front end. Data are also presented describing the first H{sup -} beam extraction experiments from a helicon plasma generator based on the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) engine design.

  11. Spectral decomposition of the aerodynamic noise generated by rotating sources

    NASA Astrophysics Data System (ADS)

    Bongiovì, Alessandro; Cattanei, Andrea

    2011-01-01

    A method is posed for separating the noise emitted by an aerodynamic source from propagation effects using spectral decomposition. This technique is applied to the power spectra of a fan measured at several rotational speeds. Although it has been conceived for rotating sources as turbomachinery rotors, the method may be easily applied to low speed stationary sources such as jets and flows in stators and about isolated airfoils. Based on the similarity theory, a clear description of the structure of the power spectrum of the received noise is given and the effect of rotational speed variations is considered as a means to obtain a data set suitable to perform the spectral decomposition. The problem is analyzed in order to clarify possibilities and limitations of the method and then an algorithm is presented which is based on the solution of the derived equations. Particular care is devoted to both the numerical details and the operative aspects. The validation of the algorithm is performed by means of numerically generated input data. Next, in order to verify the ability of the method in separating scattered from emitted sound, an automotive cooling fan has been tested in the DIMSET hemi-anechoic room in a free-field configuration and with a shielded microphone. These two apparently distinct spectra collapse to within less than 2 dB after the spectral decomposition has been performed. The tests prove the ability of the method despite the modest quantity of input data.

  12. High heat load x-ray optics research and development at the Advanced Photon Source -- An overview

    SciTech Connect

    Lee, Wah-Keat; Mills, D.M.

    1993-09-01

    Insertion devices at third generation synchrotron radiation sources such as the APS are capable of producing x-ray beams with total power in excess of 7 kilowatts or power densities of 150 watts/mm{sup 2} at a typical location of the optical components. Optical elements subjected to these types of heat fluxes will suffer considerably unless carefully designed to withstand these unprecedented power loadings. At the Advanced Photon Source (APS), we have an aggressive R&D program aimed at investigating possible methods to mitigate thermal distortions. The approaches being studied include, improved heat exchangers, use of liquid gallium and liquid nitrogen as coolants, novel crystal geometries, power filtering, and replacement of silicon with diamond for crystal monochromators. This paper will provide an overview of the high heat load x-ray optics program at the APS.

  13. Technological challenges of third generation synchrotron radiation sources

    SciTech Connect

    Cornacchia, M. ); Winick, H. . Stanford Synchrotron Radiation Lab.)

    1990-01-01

    New third generation'' synchrotron radiation research facilities are now in construction in France, Italy, Japan, Taiwan and the USA. Designs for such facilities are being developed in several other countries. Third generation facilities are based on storage rings with low electron beam emittance and space for many undulator magnets to produce radiation with extremely high brightness and coherent power. Photon beam from these rings will greatly extend present research capabilities and open up new opportunities in imaging, spectroscopy, structural and dynamic studies and other applications. The technological problems of the third generation of synchrotron radiation facilities are reviewed. These machines are designed to emit radiation of very high intensity, extreme brightness, very short pulses, and partial coherence. These performance goals put severe requirements on the quality of the electron or positron beams. Phenomena affecting the injection process and the beam lifetime are discussed. Gas desorption by synchrotron radiation and collective effects play an important role. Low emittance lattices are more sensitive to quadrupole movements and at the same time, in order not to lose the benefits of high brilliance, require tighter tolerances on the allowed movement of the photon beam source. We discuss some of the ways that should be considered to extend the performance capabilities of the facilities in the future. 14 refs., 1 fig.

  14. Laser Design for Next Generation Compton Scattering Source at LLNL

    NASA Astrophysics Data System (ADS)

    Shverdin, Miro; Albert, Felicie; Anderson, Scott; Bayramian, Andy; Betts, Shawn; Cross, Rick; Ebbers, Chris; Gibson, David; Marsh, Roark; Messerly, Michael; Hartemann, Fred; Scarpetti, Ray; Siders, Craig; Barty, Chris

    2010-11-01

    We describe laser systems designed for the next generation Mono-Energetic Gamma-Ray (MEGa-ray) Compton scattering light source at LLNL. An 80 fs Yb:doped fiber oscillator seeds a photogun drive laser (PDL) and a high energy interaction system laser (ILS). Utilizing chirped pulse amplification (CPA) in fiber, the PDL will generate 80 μJ, spatially and temporally shaped pulses at 263 nm at 120 Hz precisely synchronized to the linac RF. The PDL system employs large mode photonic bandgap fibers and large area multi-layer dielectric gratings to generate over 1mJ per pulse with high recompression fidelity prior to frequency quadrupling. The high energy, 120 W ILS utilizes (CPA) in Nd:YAG to amplify a sub-nanometer bandwidth 20 μJ pulses from a fiber system to 1 J. A novel pulse stretcher provides a dispersion of over 7000 ps/nm to expand a several picosecond wide seed pulse to 6 ns. After amplification, the pulse is recompressed to 10 ps with a hyper-dispersive pulse compressor. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  15. Harmonic Generation from Solid Targets - Optmization of Source Parameters

    NASA Astrophysics Data System (ADS)

    Zepf, Matthew; Watts, I. F.; Dangor, A. E.; Norreys, P. A.; Chambers, D. M.; Machacek, A.; Wark, J. S.; Tsakiris, G. D.

    1998-11-01

    High harmonics from solid targets have received renewed interest over the last few years. Theoretical predictions using 1 1/2 D codes suggest that very high orders (>100 ) can be generated at conversion efficiencies in excess of 10-6 [1,2] at Iλ^2 > 10^19 W/cm^2. Experiments have since been performed with pulses varying from 100 fs to 2.5 ps in duration [3-6]. The steep density gradient necessary to generate the harmonics can be generated by either ponderomotive steepening or by using ultraclean pulses which preserve the initial solid vacuum boundary. The two regimes are compared in terms of their dependence on the laser parameters and the emitted harmonic radiation. Particular emphasis will be given to measurements of the holeboring velocity, the polarisation of the harmonics and the intensity scaling in the two regimes. This comparison enables us to find the ideal parameter range for the optimization of harmonic source. [1] R. Lichters et al., Physics of Plasmas 3, 3425, (1996). [2] P. Gibbon, IEEE J. of Q. Elec. 33, 1915 (1997). [3] S. Kohlweyer, et al., Optics Comm. 177, 431 (1995). [4] P. Norreys et al., Phys. Rev. Lett., 76, 1832 (1995). [5] D. von der Linde et al., Phys. Rev. A, 52, R25 (1995) [6] M. Zepf, et al., submitted for publication in Phys. Rev. Lett.

  16. CONTAINMENT VESSEL TEMPERATURE FOR PU-238 HEAT SOURCE CONTAINER UNDER AMBIENT, FREE CONVECTION AND LOW EMISSIVITY COOLING CONDITIONS

    SciTech Connect

    Gupta, N.; Smith, A.

    2011-02-14

    The EP-61 primary containment vessel of the 5320 shipping package has been used for storage and transportation of Pu-238 plutonium oxide heat source material. For storage, the material in its convenience canister called EP-60 is placed in the EP-61 and sealed by two threaded caps with elastomer O-ring seals. When the package is shipped, the outer cap is seal welded to the body. While stored, the EP-61s are placed in a cooling water bath. In preparation for welding, several containers are removed from storage and staged to the welding booth. The significant heat generation of the contents, and resulting rapid rise in component temperature necessitates special handling practices. The test described here was performed to determine the temperature rise with time and peak temperature attained for an EP-61 with 203 watts of internal heat generation, upon its removal from the cooling water bath.

  17. Alternative Energy Sources for Heating the Stratospheres of Hot Jupiters

    NASA Astrophysics Data System (ADS)

    Marley, Mark S.; Zahnle, K.; Freedman, R.; Lodders, K.; Fortney, J.

    2009-09-01

    Spitzer Space Telescope observations have constrained the atmospheric thermal structure of many transiting extrasolar giant planets. Many of these planets, like their solar system cousins, apparently have hot stratospheres. It has been suggested that absorption in the optical by gaseous TiO and VO provides the necessary energy source to power their thermal emission. While this mechanism is certainly plausible in the hottest Jupiters, temperature inversions have also been observed in cooler planets in which TiO and VO should be condensed into grains. Motivated by the importance of photochemistry in producing important atmospheric absorbers in the solar system, we have explored the role of atmospheric sulfur photochemistry in hot Jupiter atmospheres. Our photochemical kinetics code was previously used to study various problems in solar system, including the aftermath of the S/L-9 impacts into Jupiter. We find that the optically active gases S2 and HS (mercapto) are generated photochemically and thermochemically at T > 1200 K from H2S with peak abundances between 1 and 10 mbar. S2 absorbs UV between 240 and 340 nm and is optically thick for metallicities higher than solar. HS is generally more abundant than S2 and absorbs between 300 and 460 nm. Together these species play an important role in the stratospheric energy budget of hot Jupiters and may provide a mechanism for producing temperature inversions under conditions where gaseous TiO and VO are not present. At lower temperatures, below 1200 K, we find that the atmospheric chemistry enters a different domain where the production of soots may be favored. Such soots may be responsible for the haze detected in the atmosphere of HD189733 and may also play a role in the stratospheric energy budgets of cooler planets.

  18. Production of 238PuO2 heat sources for the Cassini mission

    NASA Astrophysics Data System (ADS)

    George, Timothy G.; Foltyn, Elizabeth M.

    1998-01-01

    NASA's Cassini mission to Saturn, scheduled to launch in October, 1997, is perhaps the most ambitious interplanetary explorer ever constructed. Electric power for the spacecraft's science instruments and on-board computers will be provided by three radioisotope thermoelectric generators (RTGs) powered by 216 238PuO2-fueled General-Purpose Heat Source (GPHS) capsules. In addition, critical equipment and instruments on the spacecraft and Huygens probe will be warmed by 128 Light-Weight Radioisotope Heater Units (LWRHUs). Fabrication and assembly of the GPHS capsules and LWRHU heat sources was performed at Los Alamos National Laboratory (LANL) between January 1994 and September 1996. During this production campaign, LANL pressed and sintered 315 GPHS fuel pellets and 181 LWRHU pellets. By October 1996, NMT-9 had delivered a total of 235 GPHS capsules to EG&G Mound Applied Technologies (EG&G MAT) in Miamisburg, Ohio. EG&G MAT conditioned the capsules for use, loaded the capsules into the Cassini RTGs, tested the RTGs, and coordinated transportation to Kennedy Space Center (KSC). LANL also fabricated and assembled a total of 180 LWRHUs. The LWRHUs required for the Cassini spacecraft were shipped to KSC in mid-1997.

  19. Environmental assessment of general-purpose heat source safety verification testing

    SciTech Connect

    1995-02-01

    This Environmental Assessment (EA) was prepared to identify and evaluate potential environmental, safety, and health impacts associated with the Proposed Action to test General-Purpose Heat Source (GPHS) Radioisotope Thermoelectric Generator (RTG) assemblies at the Sandia National Laboratories (SNL) 10,000-Foot Sled Track Facility, Albuquerque, New Mexico. RTGs are used to provide a reliable source of electrical power on board some spacecraft when solar power is inadequate during long duration space missions. These units are designed to convert heat from the natural decay of radioisotope fuel into electrical power. Impact test data are required to support DOE`s mission to provide radioisotope power systems to NASA and other user agencies. The proposed tests will expand the available safety database regarding RTG performance under postulated accident conditions. Direct observations and measurements of GPHS/RTG performance upon impact with hard, unyielding surfaces are required to verify model predictions and to ensure the continual evolution of the RTG designs that perform safely under varied accident environments. The Proposed Action is to conduct impact testing of RTG sections containing GPHS modules with simulated fuel. End-On and Side-On impact test series are planned.

  20. Self-generated stochastic heating in an rf discharge

    SciTech Connect

    Lichtenberg, A.

    1992-01-01

    We have studied the nonlinear dynamics of stochastic heating arising from the reflection of electrons from moving sheaths as an underlying mechanism for electron power deposition in r.f. discharges. We examined the dynamics of the electron collision with the sheaths in the regime in which the sheath motion is small compared to the average electron velocity to de rive a mop that describes the electron motion. We have shown that for high frequency, ({omega}/2{pi}{approx gt}50MHz), the electrons will strike the moving wall with random phase. At low pressures this stochasticity is an intrinsic property of the dynamics. The stochastic electron heating leads to a power law electron distribution. The stochastic heating was determined in both the slow sheath and fast sheath velocity regimes assuming an incident Maxwellian distribution.

  1. Magnetoresistance effect of heat generation in a single-molecular spin-valve

    NASA Astrophysics Data System (ADS)

    Jiang, Feng; Yan, Yonghong; Wang, Shikuan; Yan, Yijing

    2016-02-01

    Based on non-equilibrium Green's functions' theory and small polaron transformation's technology, we study the heat generation by current through a single-molecular spin-valve. Numerical results indicate that the variation of spin polarization degree can change heat generation effectively, the spin-valve effect happens not only in electrical current but also in heat generation when Coulomb repulsion in quantum dot is smaller than phonon frequency and interestingly, when Coulomb repulsion is larger than phonon frequency, the inverse spin-valve effect appears by sweeping gate voltage and is enlarged with bias increasing. The inverse spin-valve effect will induce the unique heat magnetoresistance effect, which can be modulated from heat-resistance to heat-gain by gate voltage easily.

  2. Voltage generation of piezoelectric cantilevers by laser heating

    PubMed Central

    Hsieh, Chun-Yi; Liu, Wei-Hung; Chen, Yang-Fang; Shih, Wan Y.; Gao, Xiaotong; Shih, Wei-Heng

    2012-01-01

    Converting ambient thermal energy into electricity is of great interest in harvesting energy from the environment. Piezoelectric cantilevers have previously been shown to be an effective biosensor and a tool for elasticity mapping. Here we show that a single piezoelectric (lead-zirconate titanate (PZT)) layer cantilever can be used to convert heat to electricity through pyroelectric effect. Furthermore, piezoelectric-metal (PZT-Ti) bi-layer cantilever showed an enhanced induced voltage over the single PZT layer alone due to the additional piezoelectric effect. This type of device can be a way for converting heat energy into electricity. PMID:23258941

  3. Voltage generation of piezoelectric cantilevers by laser heating

    NASA Astrophysics Data System (ADS)

    Hsieh, Chun-Yi; Liu, Wei-Hung; Chen, Yang-Fang; Shih, Wan Y.; Gao, Xiaotong; Shih, Wei-Heng

    2012-11-01

    Converting ambient thermal energy into electricity is of great interest in harvesting energy from the environment. Piezoelectric cantilevers have previously been shown to be an effective biosensor and a tool for elasticity mapping. Here we show that a single piezoelectric (lead-zirconate titanate (PZT)) layer cantilever can be used to convert heat to electricity through pyroelectric effect. Furthermore, piezoelectric-metal (PZT-Ti) bi-layer cantilever showed an enhanced induced voltage over the single PZT layer alone due to the additional piezoelectric effect. This type of device can be a way for converting heat energy into electricity.

  4. Heat line analysis for MHD mixed convection flow of nanofluid within a driven cavity containing heat generating block

    NASA Astrophysics Data System (ADS)

    Parvin, Salma; Siddiqua, Ayesha

    2016-07-01

    Mixed convective flow and heat transfer characteristics of nanofluid inside a double lid driven cavity with a square heat generating block is analyzed numerically based on heat line approach. The water- alumina nanofluid is chosen as the operational fluid through the enclosure. The governing partial differential equations with proper boundary conditions are solved by Finite Element Method using Galerkin's weighted residual scheme. Calculations are performed for different solid volume fraction (χ) of nanoparticles 0 ≤ χ ≤ 0.15. Results are shown in terms of stream lines, isothermal lines, heat lines, average Nusselt number, average velocity and average temperature. An enhancement in heat transfer rate is observed with the increase of nanoparticles volume fraction.

  5. Study of the relation between evaluation of strain distribution on superconducting coil and mechanical heat generation

    NASA Astrophysics Data System (ADS)

    Seino, Hiroshi; Kurihara, Minoru; Herai, Toshiki; Suzuki, Eiji

    2002-10-01

    In the superconducting Maglev system, on-board superconducting magnets (SCMs) are vibrated at various frequencies according to the train speed by the electromagnetic disturbance which is caused when the train passes over ground coils. Then a mechanical loss is generated inside the inner vessel in the SCM. This phenomenon increases the heat load on the cryogenic equipment in the SCM. It has been surmised that the mechanical heat inside the inner vessel is generated by the frictional heat caused by the relative microscopic slips between fasteners and superconducting coil (SC coil). Nevertheless, heat generation mechanisms inside the inner vessel have not been studied sufficiently. In this study, we suggest a hypothesis that the frictional heat generated by the relative microscopic slips between fasteners and a SC coil will be indicated if the calculated strain distribution on the SC coil is evaluated. The results of this study supported this hypothesis.

  6. An analysis of the vapor flow and the heat conduction through the liquid-wick and pipe wall in a heat pipe with single or multiple heat sources

    NASA Technical Reports Server (NTRS)

    Chen, Ming-Ming; Faghri, Amir

    1990-01-01

    A numerical analysis is presented for the overall performance of heat pipes with single or multiple heat sources. The analysis includes the heat conduction in the wall and liquid-wick regions as well as the compressibility effect of the vapor inside the heat pipe. The two-dimensional elliptic governing equations in conjunction with the thermodynamic equilibrium relation and appropriate boundary conditions are solved numerically. The solutions are in agreement with existing experimental data for the vapor and wall temperatures at both low and high operating temperatures.

  7. Design of a nuclear isotope heat source assembly for a spaceborne mini-Brayton power module.

    NASA Technical Reports Server (NTRS)

    Wein, D.; Gorland, S. H.

    1973-01-01

    Results of a study to develop a feasible design definition of a heat source assembly (HSA) for use in nominal 500-, 1200-, or 2000-W(e) mini-Brayton spacecraft power systems. The HSA is a modular design which is used either as a single unit to provide thermal energy to the 500-W(e) mini-Brayton power module or in parallel with one or two additional HSAs for the 1200- or 2000-W(e) power module systems. Principal components consist of a multihundred watt RTG isotope heat source, a heat source heat exchanger which transfers the thermal energy from the heat source to the mini-Brayton power conversion system, an auxiliary cooling system which provides requisite cooling during nonoperation of the power conversion module and an emergency cooling system which precludes accidental release of isotope fuel in the event of system failure.

  8. Evaluation of water source heat pumps for the Juneau, Alaska Area

    SciTech Connect

    Jacobsen, J.J.; King, J.C.; Eisenhauer, J.L.; Gibson, C.I.

    1980-07-01

    The purposes of this project were to evaluate the technical and economic feasibility of water source heat pumps (WSHP) for use in Juneau, Alaska and to identify potential demonstration projects to verify their feasibility. Information is included on the design, cost, and availability of heat pumps, possible use of seawater as a heat source, heating costs with WSHP and conventional space heating systems, and life cycle costs for WSHP-based heating systems. The results showed that WSHP's are technically viable in the Juneau area, proper installation and maintenance is imperative to prevent equipment failures, use of WSHP would save fuel oil but increase electric power consumption. Life cycle costs for WSHP's are about 8% above that for electric resistance heating systems, and a field demonstration program to verify these results should be conducted. (LCL)

  9. Millimeter waves as a source of selective heating of skin.

    PubMed

    Zhadobov, Maxim; Alekseev, Stanislav I; Le Dréan, Yves; Sauleau, Ronan; Fesenko, Evgeny E

    2015-09-01

    This study demonstrates that 20-100 GHz range can be used for spatially-accurate focusing of heating inside the skin achieved by varying frequency and exposure beam size, as well as by enforcing air convection. The latter is also used to reduce overheating of skin surface. Heating at different skin depths depending on these parameters is investigated in detail using the hybrid bio-heat equation. In particular, it is shown that decreasing frequency and/or increasing exposure beam size at forced airflow result in elevation of heating of deeper layers of tissue and decrease of skin surface temperature. Changes of water content within 15%, which exceed those due to aging and presence of tumors, only slightly affect heating. Exposure intensity necessary to reach a target temperature significantly increases in different areas of body with elevated blood flow. Dependence on exposure intensity and hyperthermia treatment duration is also investigated and discussed. Results of this study suggest that the lower part of the millimeter-wave range is an attractive alternative for non-invasive thermal treatment of skin cancer with a high spatial resolution. PMID:26179286

  10. Millimeter waves as a source of selective heating of skin.

    PubMed

    Zhadobov, Maxim; Alekseev, Stanislav I; Le Dréan, Yves; Sauleau, Ronan; Fesenko, Evgeny E

    2015-09-01

    This study demonstrates that 20-100 GHz range can be used for spatially-accurate focusing of heating inside the skin achieved by varying frequency and exposure beam size, as well as by enforcing air convection. The latter is also used to reduce overheating of skin surface. Heating at different skin depths depending on these parameters is investigated in detail using the hybrid bio-heat equation. In particular, it is shown that decreasing frequency and/or increasing exposure beam size at forced airflow result in elevation of heating of deeper layers of tissue and decrease of skin surface temperature. Changes of water content within 15%, which exceed those due to aging and presence of tumors, only slightly affect heating. Exposure intensity necessary to reach a target temperature significantly increases in different areas of body with elevated blood flow. Dependence on exposure intensity and hyperthermia treatment duration is also investigated and discussed. Results of this study suggest that the lower part of the millimeter-wave range is an attractive alternative for non-invasive thermal treatment of skin cancer with a high spatial resolution.

  11. Pore-space alteration in source rock (shales) during hydrocarbons generation: laboratory experiment

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, D. R.; Korost, D. V.; Nadezhkin, D. V.

    2013-12-01

    Hydrocarbons (HC) are generated from solid organic matter (kerogen) due to thermocatalytic reactions. The rate of such reactions shows direct correlation with temperature and depends on the depth of source rock burial. Burial of sedimentary rock is also inevitably accompanied by its structural alteration owing to compaction, dehydration and re-crystallization. Processes of HC generation, primary migration and structural changes are inaccessible for direct observation in nature, but they can be studied in laboratory experiments. Experiment was carried out with a clayey-carbonate rock sample of the Domanik Horizon taken from boreholes drilled in the northeastern part of the south Tatar arch. The rock chosen fits the very essential requirements - high organic matter content and its low metamorphic grade. Our work aimed at laboratory modeling of HC generation in an undisturbed rock sample by its heating in nitrogen atmosphere based on a specified temperature regime and monitoring alterations in the pore space structure. Observations were carried out with a SkyScan-1172 X-ray microtomography scanner (resulting scan resolution of 1 μm). A cylinder, 44 mm in diameter, was prepared from the rock sample for the pyrolitic and microtomographic analyses. Scanning procedures were carried out in 5 runs. Temperature interval for each run had to match the most important stage of HC generation in the source rock, namely: (1) original structure; (2) 100-300°C - discharge of free and adsorbed HC and water; (3) 300-400°C - initial stage of HC formation owing to high-temperature pyrolysis of the solid organic matter and discharge of the chemically bound water; (4) 400-470°C - temperature interval fitting the most intense stage of HC formation; (5) 470-510°C - final stage of HC formation. Maximum sample heating in the experiment was determined as temperature of the onset of active decomposition of carbonates, i.e., in essence, irreversible metamorphism of the rock. Additional

  12. Next Generation Nuclear Plant Steam Generator and Intermediate Heat Exchanger Materials Research and Development Plan

    SciTech Connect

    J. K. Wright

    2010-09-01

    DOE has selected the High Temperature Gas-cooled Reactor (HTGR) design for the Next Generation Nuclear Plant (NGNP) Project. The NGNP will demonstrate the use of nuclear power for electricity and hydrogen production. It will have an outlet gas temperature in the range of 900°C and a plant design service life of 60 years. The reactor design will be a graphite moderated, helium-cooled, prismatic or pebble-bed reactor and use low-enriched uranium, Tri-Isotopic (TRISO)-coated fuel. The plant size, reactor thermal power, and core configuration will ensure passive decay heat removal without fuel damage or radioactive material releases during accidents. The NGNP Materials Research and Development (R&D) Program is responsible for performing R&D on likely NGNP materials in support of the NGNP design, licensing, and construction activities. Today’s high-temperature alloys and associated ASME Codes for reactor applications are approved up to 760°C. However, some primary system components, such as the Intermediate Heat Exchanger (IHX) for the NGNP will require use of materials that can withstand higher temperatures. The thermal, environmental, and service life conditions of the NGNP will make selection and qualification of some high-temperature materials a significant challenge. Examples include materials for the core barrel and core internals, such as the control rod sleeves. The requirements of the materials for the IHX are among the most demanding. Selection of the technology and design configuration for the NGNP must consider both the cost and risk profiles to ensure that the demonstration plant establishes a sound foundation for future commercial deployments. The NGNP challenge is to achieve a significant advancement in nuclear technology while at the same time setting the stage for an economically viable deployment of the new technology in the commercial sector soon after 2020. A number of solid solution strengthened nickel based alloys have been considered for

  13. The partition of energy associated with tropical heat sources

    NASA Technical Reports Server (NTRS)

    Silva-Dias, P. L.; Paegle, J. N.

    1985-01-01

    Data sets derived from observations during the First GARP Global Experiment (FGGE) have permitted the study of the behavior of the tropical atmosphere to an extent not possible before. The present summary discusses characteristics of the tropical atmosphere which may be a result of tropical heating. It is shown that the meridional component of the divergent wind is of the same order of magnitude an he rotational meridional wind for the planetary tropical scales. Furthermore, the first and second internal modes dominate over most of the tropics, and it is shown that gravity and Kelvin codes are the main contributors to the total tropical divergence. Comparison with averaged station precipitation data and heating estimates obtained from Goddard Laboratory for Atmospheric Science (GLAS)/National Aeronautics and Space Administration (NASA) show good correspondence between areas with maximum internal mode energy and regions with pronounced latent heat release.

  14. A Next Generation Light Source Facility at LBNL

    SciTech Connect

    Corlett, J.N.; Austin, B.; Baptiste, K.M.; Byrd, J.M.; Denes, P.; Donahue, R.; Doolittle, L.; Falcone, R.W.; Filippetto, D.; Fournier, S.; Li, D.; Padmore, H.A.; Papadopoulos, C.; Pappas, C.; Penn, G.; Placidi, M.; Prestemon, S.; Prosnitz, D.; Qiang, J.; Ratti, A.; Reinsch, M.; Sannibale, F.; Schlueter, R.; Schoenlein, R.W.; Staples, J.W.; Vecchione, T.; Venturini, M.; Wells, R.; Wilcox, R.; Wurtele, J.; Charman, A.; Kur, E.; Zholents, A.A.

    2011-03-23

    The Next Generation Light Source (NGLS) is a design concept, under development at LBNL, for a multibeamline soft x-ray FEL array powered by a ~;;2 GeV superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. The CW superconducting linear accelerator is supplied by a high-brightness, highrepetition- rate photocathode electron gun. Electron bunches are distributed from the linac to the array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. Individual FELs may be configured for EEHG, HGHG, SASE, or oscillator mode of operation, and will produce high peak and average brightness x-rays with a flexible pulse format, with pulse durations ranging from sub-femtoseconds to hundreds of femtoseconds.

  15. Thermal Analysis of Step 2 GPHS for Next Generation Radioisotope Power Source Missions

    NASA Astrophysics Data System (ADS)

    Pantano, David R.; Hill, Dennis H.

    2005-02-01

    The Step 2 General Purpose Heat Source (GPHS) is a slightly larger and more robust version of the heritage GPHS modules flown on previous Radioisotope Thermoelectric Generator (RTG) missions like Galileo, Ulysses, and Cassini. The Step 2 GPHS is to be used in future small radioisotope power sources, such as the Stirling Radioisotope Generator (SRG110) and the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). New features include an additional central web of Fine Weave Pierced Fabric (FWPF) graphite in the aeroshell between the two Graphite Impact Shells (GIS) to improve accidental reentry and impact survivability and an additional 0.1-inch of thickness to the aeroshell broad faces to improve ablation protection. This paper details the creation of the thermal model using Thermal Desktop and AutoCAD interfaces and provides comparisons of the model to results of previous thermal analysis models of the heritage GPHS. The results of the analysis show an anticipated decrease in total thermal gradient from the aeroshell to the iridium clads compared to the heritage results. In addition, the Step 2 thermal model is investigated under typical SRG110 boundary conditions, with cover gas and gravity environments included where applicable, to provide preliminary guidance for design of the generator. Results show that the temperatures of the components inside the GPHS remain within accepted design limits during all envisioned mission phases.

  16. Design of a Nb3Sn Magnet for a 4th Generation ECR Ion Source

    SciTech Connect

    Prestemon, S,; Trillaud, F.; Caspi, S.; Ferracin, P.; Sabbi, G. L.; Lyneis, C. M.; Leitner, D.; Todd, D. S.; Hafalia, R.

    2008-08-17

    The next generation of Electron Cyclotron Resonant (ECR) ion sources are expected to operate at a heating radio frequency greater than 40 GHz. The existing 3rd generation systems, exemplified by the state of the art system VENUS, operate in the 10-28 GHz range, and use NbTi superconductors for the confinement coils. The magnetic field needed to confine the plasma scales with the rf frequency, resulting in peak fields on the magnets of the 4th generation system in excess of 10 T. High field superconductors such as Nb{sub 3}Sn must therefore be considered. The magnetic design of a 4th. generation ECR ion source operating at an rf frequency of 56 GHz is considered. The analysis considers both internal and external sextupole configurations, assuming commercially available Nb{sub 3}Sn material properties. Preliminary structural design issues are discussed based on the forces and margins associated with the coils in the different configurations, leading to quantitative data for the determination of a final magnet design.

  17. Transition to chaos in a square enclosure containing internal heat sources

    SciTech Connect

    Baytas, A.C.

    1995-09-01

    A numerical investigation is performed to study the transition from steady to chaotic flow of a fluid confined in a two-dimensional square cavity. The cavity has rigid walls of constant temperature containing uniformly distributed internal heat source. Effects of the Rayleigh number of flow and heat transfer rates are studied. In addition to, same problem is solved for sinusoidally changing internal heat source to show its effect on the flow model and heat transfer of the enclosures. Details of oscillatory solutions and flow bifurcations are presented.

  18. Groundwater as an alternative energy source for space heating and cooling, geothermal heat extraction

    NASA Astrophysics Data System (ADS)

    1980-07-01

    The technology of the groundwater heat pump (GWHP), its applicability to the Toledo metropolitan area council of governments region, and relative economics of its use are addressed. The operation of the GWHP in both the heating and cooling modes is discussed as well as its advantages and disadvantages. A comparison is made between GWHP and other heating and cooling systems both in operation and cost. A detailed analysis is given to the legal implications of direct groundwater use and its related impacts.

  19. A combined power and ejector refrigeration cycle for low temperature heat sources

    SciTech Connect

    Zheng, B.; Weng, Y.W.

    2010-05-15

    A combined power and ejector refrigeration cycle for low temperature heat sources is under investigation in this paper. The proposed cycle combines the organic Rankine cycle and the ejector refrigeration cycle. The ejector is driven by the exhausts from the turbine to produce power and refrigeration simultaneously. A simulation was carried out to analyze the cycle performance using R245fa as the working fluid. A thermal efficiency of 34.1%, an effective efficiency of 18.7% and an exergy efficiency of 56.8% can be obtained at a generating temperature of 395 K, a condensing temperature of 298 K and an evaporating temperature of 280 K. Simulation results show that the proposed cycle has a big potential to produce refrigeration and most exergy losses take place in the ejector. (author)

  20. Optimization of idealized ORC in domestic combined heat and power generation

    NASA Astrophysics Data System (ADS)

    Rybiński, Witold; Mikielewicz, Jarosław

    2013-09-01

    Organic Rankine cycle (ORC) is used, amongst the others, in geothermal facilities, in waste heat recovery or in domestic combined heat and power (CHP) generation. The paper presents optimization of an idealized ORC equivalent of the Carnot cycle with non-zero temperature difference in heat exchangers and with energy dissipation caused by the viscous fluid flow. In this analysis the amount of heat outgoing from the ORC is given. Such a case corresponds to the application of an ORC in domestic CHP. This assumption is different from the most of ORC models where the incoming amount of heat is given.

  1. Carbon-14 Source Terms and Generation in Fusion Power Cores

    NASA Astrophysics Data System (ADS)

    Khripunov, V. I.; Kurbatov, D. K.; Subbotin, M. L.

    2008-12-01

    A consecutive study of the source terms of 14C as the major contributor to the external costs of fusion and its production rate was performed by system and neutron activation analysis. It shows that the specific 14C activity induced in the low activation structural materials, coolants and breeders suggested for future fusion power reactor cores is significantly dependent upon the assumption for nitrogen content. The determined range of the specific 14C activity ˜2-20 TBq/GW(e)a induced by the near-term water-cooled, gas-cooled and advanced liquid lithium and lithium-lead self-cooled fusion power reactors is given in the paper regarding the values for natural 14C background and artificial 14C sources as fission power reactors and nuclear tests. It is definitely recommended to minimize the nitrogen content below 0.01 wt.% in the beryllium multipliers and in the structural materials, SiC/SiC composite including. Then due to environmental and waste disposal reasons the 14C generation in fusion power blankets will have negligible impact on the cost.

  2. Generation of Chorus Wave Emissions in the Source Region

    NASA Astrophysics Data System (ADS)

    Schriver, D.; Ashour-Abdalla, M.; Leboeuf, J.; Winningham, J. D.; Pickett, J. S.; Santolik, O.; Goldstein, M. L.

    2006-12-01

    Chorus waves with frequencies below the electron gyrofrequency (fce) are observed in the inner radiation belt and may play a role in the acceleration of electrons. To understand how these waves are generated and what their effects are on electrons, a study has been carried out using Cluster satellite observations and numerical simulations. The WBD, STAFF, and Whisper instruments onboard Cluster have made observations of chorus waves within the source region in the near-Earth magnetosphere and the PEACE electron instrument has shown the presence of multiple electron species of different temperature from cold (10's eV), to warm (100's eV) to hot (> keV). The warm species is highly anisotropic with perpendicular temperature as much as 10 times the parallel temperature. Using the electron observations made in the generation region, a linear theory and simulation study has been undertaken. Linear theory shows that the observed electron species are unstable to whistler waves at frequencies in the range 0.7-0.8 fce. To understand how the instability saturates and the ensuing wave-particle interactions, an electromagnetic particle in cell simulation study has been carried out using observed parameters. The effects the chorus waves have on electrons and the implications for the radiation belt region will be discussed.

  3. Quantity, Quality, and Availability of Waste Heat from United States Thermal Power Generation.

    PubMed

    Gingerich, Daniel B; Mauter, Meagan S

    2015-07-21

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJ(th) of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040.

  4. Quantity, Quality, and Availability of Waste Heat from United States Thermal Power Generation.

    PubMed

    Gingerich, Daniel B; Mauter, Meagan S

    2015-07-21

    Secondary application of unconverted heat produced during electric power generation has the potential to improve the life-cycle fuel efficiency of the electric power industry and the sectors it serves. This work quantifies the residual heat (also known as waste heat) generated by U.S. thermal power plants and assesses the intermittency and transport issues that must be considered when planning to utilize this heat. Combining Energy Information Administration plant-level data with literature-reported process efficiency data, we develop estimates of the unconverted heat flux from individual U.S. thermal power plants in 2012. Together these power plants discharged an estimated 18.9 billion GJ(th) of residual heat in 2012, 4% of which was discharged at temperatures greater than 90 °C. We also characterize the temperature, spatial distribution, and temporal availability of this residual heat at the plant level and model the implications for the technical and economic feasibility of its end use. Increased implementation of flue gas desulfurization technologies at coal-fired facilities and the higher quality heat generated in the exhaust of natural gas fuel cycles are expected to increase the availability of residual heat generated by 10.6% in 2040. PMID:26061407

  5. Heat sources for tertiary metamorphism and anatexis in the Annapurna-Manaslu region, central Nepal

    NASA Technical Reports Server (NTRS)

    England, Philip; Le Fort, Patrick; Molnar, Peter; Pecher, Arnaud

    1992-01-01

    The metamorphic evolution of the rocks near the Main Central Thrust in the Annapurna-Manaslu region of central Nepal is examined. In this region, all three types of metamorphic features can be observed: regional metamorphism, anatectic granitoids, and inverted metamorphic isograds. In this work, each phase of metamorphism is treated separately to estimate the heat sources required for each process. This approach makes it possible to identify the important parameters for each process, to draw preliminary conclusions about the heat sources required for each of these phases, and to determine which parameters need to be measured more precisely in order to constrain these heat sources.

  6. Federal Technology Alert: Ground-Source Heat Pumps Applied to Federal Facilities--Second Edition

    SciTech Connect

    Hadley, Donald L.

    2001-03-01

    This Federal Technology Alert, which was sponsored by the U.S. Department of Energy's Office of Federal Energy Management Programs, provides the detailed information and procedures that a Federal energy manager needs to evaluate most ground-source heat pump applications. This report updates an earlier report on ground-source heat pumps that was published in September 1995. In the current report, general benefits of this technology to the Federal sector are described, as are ground-source heat pump operation, system types, design variations, energy savings, and other benefits. In addition, information on current manufacturers, technology users, and references for further reading are provided.

  7. Advanced variable speed air source integrated heat pump (AS-IHP) development - CRADA final report

    SciTech Connect

    Baxter, Van D.; Rice, C. Keith; Munk, Jeffrey D.; Ally, Moonis Raza; Shen, Bo

    2015-09-30

    Between August 2011 and September 2015, Oak Ridge National Laboratory (ORNL) and Nordyne, LLC (now Nortek Global HVAC LLC, NGHVAC) engaged in a Cooperative Research and Development Agreement (CRADA) to develop an air-source integrated heat pump (AS-IHP) system for the US residential market. Two generations of laboratory prototype systems were designed, fabricated, and lab-tested during 2011-2013. Performance maps for the system were developed using the latest research version of the DOE/ORNL Heat Pump Design Model, or HPDM, (Rice 1991; Rice and Jackson 2005; Shen et al 2012) as calibrated against the lab test data. These maps were the input to the TRNSYS (SOLAR Energy Laboratory, et al, 2010) system to predict annual performance relative to a baseline suite of equipment meeting minimum efficiency standards in effect in 2006 (combination of 13 SEER air-source heat pump (ASHP) and resistance water heater with Energy Factor (EF) of 0.9). Predicted total annual energy savings, while providing space conditioning and water heating for a tight, well insulated 2600 ft2 (242 m2) house at 5 U.S. locations, ranged from 46 to 61%, averaging 52%, relative to the baseline system (lowest savings at the cold-climate Chicago location). Predicted energy use for water heating was reduced 62 to 76% relative to resistance WH. Based on these lab prototype test and analyses results a field test prototype was designed and fabricated by NGHVAC. The unit was installed in a 2400 ft2 (223 m2) research house in Knoxville, TN and field tested from May 2014 to April 2015. Based on the demonstrated field performance of the AS-IHP prototype and estimated performance of a baseline system operating under the same loads and weather conditions, it was estimated that the prototype would achieve ~40% energy savings relative to the minimum efficiency suite. The estimated WH savings were >60% and SC mode savings were >50%. But estimated SH savings were only about 20%. It is believed that had the test

  8. Environmental and radiological-safety studies: interaction of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Progress report, January 1-March 31, 1982

    SciTech Connect

    Matlack, G.M.; Patterson, J.H.

    1982-06-01

    Although existing radioisotope thermoelectric generator designs have proved more than adequately safe, more information is continually sought about the heat sources to improve their safety. The work here includes studies of the effects on the heat sources of terrestrial and aquatic environments and also of the effects of the heat sources on various simulated environments. This progress report presents recent data from environmental chamber and aquatic experiments and gives the present status of the experiments.

  9. Source component mixing in the regions of arc magma generation

    NASA Astrophysics Data System (ADS)

    Arculus, Richard J.; Powell, Roger

    1986-05-01

    Most recent workers attribute the main features of island arc basalt geochemistry to variable contributions of at least two source components. The major source appears to be the peridotitic wedge of upper mantle overlying the subducted slab, but the nature of the second component and the processes by which the sources become mixed during genesis of arc magmas are in dispute. A metasomatic addition to the wedge resulting from devolatilization in the slab is the simplest explanation of the marked enrichment of the alkali and alkaline earth elements with respect to the rare earths in island arc basalts, together with the variably developed trends in Pb, Sr, and Nd isotopic data toward sedimentary contaminants. However, lack of the correlations between relative degrees of trace element fractionation and radiogenic isotopic ratios expected of such processes requires a more complex explanation. Alternative models that suggest that all of the characteristics of island arc basalts can be accounted for by melting of an intraoceanic, hot spot type of mantle source also face specific difficulties, particularly with regard to the strong depletions of trace high-field-strength elements in arc compared with hot spot magmas. A possible resolution of these specific geochemical difficulties may lie in dynamic transport processes within the wedge linked with the slab through coupled drag, and the marked depression of mantle isotherms in subduction zones. Inefficient escape of melts and subsequent repeated freezing within the overturning wedge can lead to local mineralogic and geochemical heterogeneity of the peridotite overlying the slab. Fluids released from the slab may infiltrate the heterogeneous wedge and preferentially scavenge the alkalis and alkaline earths with respect to the rare earths and high field strength elements from locally enriched portions of the wedge. Incorporation of such metasomatic fluids in renewed melting at shallower but hotter levels within the wedge can

  10. Arc plasma generator of atomic driver for steady-state negative ion source

    NASA Astrophysics Data System (ADS)

    Ivanov, A. A.; Belchenko, Yu. I.; Davydenko, V. I.; Ivanov, I. A.; Kolmogorov, V. V.; Listopad, A. A.; Mishagin, V. V.; Putvinsky, S. V.; Shulzhenko, G. I.; Smirnov, A.

    2014-02-01

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

  11. Arc plasma generator of atomic driver for steady-state negative ion source

    SciTech Connect

    Ivanov, A. A.; Belchenko, Yu. I.; Davydenko, V. I.; Ivanov, I. A.; Kolmogorov, V. V.; Listopad, A. A. Mishagin, V. V.; Shulzhenko, G. I.; Putvinsky, S. V.; Smirnov, A.

    2014-02-15

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB{sub 6} cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

  12. Arc plasma generator of atomic driver for steady-state negative ion source.

    PubMed

    Ivanov, A A; Belchenko, Yu I; Davydenko, V I; Ivanov, I A; Kolmogorov, V V; Listopad, A A; Mishagin, V V; Putvinsky, S V; Shulzhenko, G I; Smirnov, A

    2014-02-01

    The paper reviews the results of development of steady-state arc-discharge plasma generator with directly heated LaB6 cathode. This arc-discharge plasma generator produces a plasma jet which is to be converted into an atomic one after recombination on a metallic plate. The plate is electrically biased relative to the plasma in order to control the atom energies. Such an intensive jet of hydrogen atoms can be used in negative ion sources for effective production of negative ions on a cesiated surface of plasma grid. All elements of the plasma generator have an augmented water cooling to operate in long pulse mode or in steady state. The thermo-mechanical stresses and deformations of the most critical elements of the plasma generator were determined by simulations. Magnetic field inside the discharge chamber was optimized to reduce the local power loads. The first tests of the steady-state arc plasma generator prototype have performed in long-pulse mode.

  13. Multi-Bed Multi-Stage Adsorption Refrigeration Cycle-Reducing Driving Heat Source Temperature

    NASA Astrophysics Data System (ADS)

    Alam, K. C. Amanul; Akahira, Akira; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao; Saha, Bidyut Baran; Koyama, Shigeru; Ng, Kim Choon; Chua, Hui Tong

    The study aims at designing a multi-bed multi-stage adsorption chiller that can be driven by waste heat at near ambient temperature. The chiller is designed such a way that it can be switched into different modes depending on the driving heat source temperature. Stage regeneration techniques have been applied to operate the chiller by relatively low temperature heat source. Driving heat source temperature is validated by simulated data and the performances obtained from different modes are compared. In terms of COP (Coefficient of performance),the chiller shows best performance in conventional single-stage mode for driving heat source temperature greater than 60°C, two stage mode for driving source temperature between 42 and 60°C,in three-stage mode for driving source temperature less than 42°C. In terms of cooling capacity, it shows the best performance in single-stage mode for heat source temperature greater than 70°C. The mass recovery process in single-stage mode is also examined. It is seen that the mass recovery process improve cooling capacity significantly, specially for the low regenerating temperature region.

  14. Alternate energy source usage for in situ heat treatment processes

    DOEpatents

    Stone, Jr., Francis Marion; Goodwin, Charles R.; Richard, Jr., James

    2011-03-22

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one system for providing power to one or more subsurface heaters is described herein. The system may include an intermittent power source; a transformer coupled to the intermittent power source, and a tap controller coupled to the transformer. The transformer may be configured to transform power from the intermittent power source to power with appropriate operating parameters for the heaters. The tap controller may be configured to monitor and control the transformer so that a constant voltage is provided to the heaters from the transformer regardless of the load of the heaters and the power output provided by the intermittent power source.

  15. National Certification Standard for Ground Source Heat Pump Personnel

    SciTech Connect

    Kelly, John

    2013-07-31

    The National Certification Standard for the Geothermal Heat Pump Industry adds to the understanding of the barriers to rapid growth of the geothermal heat pump (GHP) industry by bringing together for the first time an analysis of the roles and responsibilities of each of the individual job tasks involved in the design and installation of GHP systems. The standard addresses applicable qualifications for all primary personnel involved in the design, installation, commissioning, operation and maintenance of GHP systems, including their knowledge, skills and abilities. The resulting standard serves as a foundation for subsequent development of curriculum, training and certification programs, which are not included in the scope of this project, but are briefly addressed in the standard to describe ways in which the standard developed in this project may form a foundation to support further progress in accomplishing those other efforts. Follow-on efforts may use the standard developed in this project to improve the technical effectiveness and economic feasibility of curriculum development and training programs for GHP industry personnel, by providing a more complete and objective assessment of the individual job tasks necessary for successful implementation of GHP systems. When incorporated into future certification programs for GHP personnel, the standard will facilitate increased consumer confidence in GHP technology, reduce the potential for improperly installed GHP systems, and assure GHP system quality and performance, all of which benefit the public through improved energy efficiency and mitigated environmental impacts of the heating and cooling of homes and businesses.

  16. The numerical simulation of heat transfer during a hybrid laser-MIG welding using equivalent heat source approach

    NASA Astrophysics Data System (ADS)

    Bendaoud, Issam; Matteï, Simone; Cicala, Eugen; Tomashchuk, Iryna; Andrzejewski, Henri; Sallamand, Pierre; Mathieu, Alexandre; Bouchaud, Fréderic

    2014-03-01

    The present study is dedicated to the numerical simulation of an industrial case of hybrid laser-MIG welding of high thickness duplex steel UR2507Cu with Y-shaped chamfer geometry. It consists in simulation of heat transfer phenomena using heat equivalent source approach and implementing in finite element software COMSOL Multiphysics. A numerical exploratory designs method is used to identify the heat sources parameters in order to obtain a minimal required difference between the numerical results and the experiment which are the shape of the welded zone and the temperature evolution in different locations. The obtained results were found in good correspondence with experiment, both for melted zone shape and thermal history.

  17. Heat flow and brine generation following the Chesapeake Bay bolide impact

    USGS Publications Warehouse

    Sanford, W.

    2003-01-01

    Calculations indicate that the impact of an asteroid or comet on the Atlantic Coastal Plain 35 million years ago created subsequent hydrothermal activity and conditions suitable for phase separation and the creation of the brine observed in the groundwater at the site today. A calculation of groundwater velocity using Darcy's law suggests flow rates are insufficient to have moved the water out of the crater within 35 million years. A similar calculation using Pick's law demonstrates that solutes cannot have escaped by molecular diffusion since the impact. Simulations from other investigators using shock-physics codes indicate that the crust would have been vaporized or melted down to at least 2 km at the time of impact. Based on these calculations, a simulation of heat conduction was made assuming a 1000 ??C initial crustal temperature. The hot crust acted as a heat source, with temperatures peaking in the overlying sediment about 10,000 years later. The pressure and temperature conditions within the sediment during that time would have been favorable for phase separation and generation of a residual brine, which may be found today in the inner crater. ?? 2003 Elsevier Science B.V. All rights reserved.

  18. GEO3D - Three-Dimensional Computer Model of a Ground Source Heat Pump System

    SciTech Connect

    James Menart

    2013-06-07

    This file is the setup file for the computer program GEO3D. GEO3D is a computer program written by Jim Menart to simulate vertical wells in conjunction with a heat pump for ground source heat pump (GSHP) systems. This is a very detailed three-dimensional computer model. This program produces detailed heat transfer and temperature field information for a vertical GSHP system.

  19. Energy recovery during expansion of compressed gas using power plant low-quality heat sources

    DOEpatents

    Ochs, Thomas L.; O'Connor, William K.

    2006-03-07

    A method of recovering energy from a cool compressed gas, compressed liquid, vapor, or supercritical fluid is disclosed which includes incrementally expanding the compressed gas, compressed liquid, vapor, or supercritical fluid through a plurality of expansion engines and heating the gas, vapor, compressed liquid, or supercritical fluid entering at least one of the expansion engines with a low quality heat source. Expansion engines such as turbines and multiple expansions with heating are disclosed.

  20. An amplitude and phase control system for the TFTR rf heating sources

    SciTech Connect

    Cutsogeorge, G.

    1989-04-01

    Feedback loops that control the amplitude and phase of the rf heating sources on TFTR are described. The method for providing arc protection is also discussed. Block diagrams and Bode plots are included. 6 figs.

  1. Impact of various operating modes on performance and emission parameters of small heat source

    NASA Astrophysics Data System (ADS)

    Vician, Peter; Holubčík, Michal; Palacka, Matej; Jandačka, Jozef

    2016-06-01

    Thesis deals with the measurement of performance and emission parameters of small heat source for combustion of biomass in each of its operating modes. As the heat source was used pellet boiler with an output of 18 kW. The work includes design of experimental device for measuring the impact of changes in air supply and method for controlling the power and emission parameters of heat sources for combustion of woody biomass. The work describes the main factors that affect the combustion process and analyze the measurements of emissions at the heat source. The results of experiment demonstrate the values of performance and emissions parameters for the different operating modes of the boiler, which serve as a decisive factor in choosing the appropriate mode.

  2. Physics of heat generation using magnetic nanoparticles for hyperthermia.

    PubMed

    Dennis, Cindi L; Ivkov, Robert

    2013-12-01

    Magnetic nanoparticle hyperthermia and thermal ablation have been actively studied experimentally and theoretically. In this review, we provide a summary of the literature describing the properties of nanometer-scale magnetic materials suspended in biocompatible fluids and their interactions with external magnetic fields. Summarised are the properties and mechanisms understood to be responsible for magnetic heating, and the models developed to understand the behaviour of single-domain magnets exposed to alternating magnetic fields. Linear response theory and its assumptions have provided a useful beginning point; however, its limitations are apparent when nanoparticle heating is measured over a wide range of magnetic fields. Well-developed models (e.g. for magnetisation reversal mechanisms and pseudo-single domain formation) available from other fields of research are explored. Some of the methods described include effects of moment relaxation, anisotropy, nanoparticle and moment rotation mechanisms, interactions and collective behaviour, which have been experimentally identified to be important. Here, we will discuss the implicit assumptions underlying these analytical models and their relevance to experiments. Numerical simulations will be discussed as an alternative to these simple analytical models, including their applicability to experimental data. Finally, guidelines for the design of optimal magnetic nanoparticles will be presented. PMID:24131317

  3. Stability analysis of Rayleigh-Bénard convection in a cylinder with internal heat generation

    NASA Astrophysics Data System (ADS)

    Wang, Bo-Fu; Zhou, Lin; Wan, Zhen-Hua; Ma, Dong-Jun; Sun, De-Jun

    2016-07-01

    The flow instabilities of Rayleigh-Bénard convection in a cylinder with effect of uniform internal heat source are investigated numerically. The instabilities of the static state and of axisymmetric flows are investigated by linear stability analysis. The convection threshold depends on the strength of internal heat source q and the aspect ratio of the cylinder Γ . The stability of axisymmetric flows is strongly affected by these two parameters, as well as the Prandtl number Pr. Depending on the value of q , three regimes are identified: weak internal heating, moderate internal heating, and strong internal heating regime. In a weak internal heating regime, the instability characteristics are similar to Rayleigh-Bénard convection. In a moderate internal heating regime, intense interaction of buoyancy instability and hydrodynamic instability result in complex instability curves. When q is large enough, the internal heating effect overwhelms the boundary heating effect. Specifically, the influence of Pr on instability is studied at a moderate internal heat strength q =6.4 . An extremely multivalued stability curve is observed. At most five critical Rayleigh numbers can be determined for the axisymmetry-breaking instability at a certain Prandtl number. An axisymmetric unsteady instability mode is observed as well. By nonlinear simulation, the oscillatory flow patterns are obtained, and the axisymmetry-breaking bifurcation of the unsteady toroidal flow is studied.

  4. Stability analysis of Rayleigh-Bénard convection in a cylinder with internal heat generation.

    PubMed

    Wang, Bo-Fu; Zhou, Lin; Wan, Zhen-Hua; Ma, Dong-Jun; Sun, De-Jun

    2016-07-01

    The flow instabilities of Rayleigh-Bénard convection in a cylinder with effect of uniform internal heat source are investigated numerically. The instabilities of the static state and of axisymmetric flows are investigated by linear stability analysis. The convection threshold depends on the strength of internal heat source q and the aspect ratio of the cylinder Γ. The stability of axisymmetric flows is strongly affected by these two parameters, as well as the Prandtl number Pr. Depending on the value of q, three regimes are identified: weak internal heating, moderate internal heating, and strong internal heating regime. In a weak internal heating regime, the instability characteristics are similar to Rayleigh-Bénard convection. In a moderate internal heating regime, intense interaction of buoyancy instability and hydrodynamic instability result in complex instability curves. When q is large enough, the internal heating effect overwhelms the boundary heating effect. Specifically, the influence of Pr on instability is studied at a moderate internal heat strength q=6.4. An extremely multivalued stability curve is observed. At most five critical Rayleigh numbers can be determined for the axisymmetry-breaking instability at a certain Prandtl number. An axisymmetric unsteady instability mode is observed as well. By nonlinear simulation, the oscillatory flow patterns are obtained, and the axisymmetry-breaking bifurcation of the unsteady toroidal flow is studied.

  5. Stability analysis of Rayleigh-Bénard convection in a cylinder with internal heat generation.

    PubMed

    Wang, Bo-Fu; Zhou, Lin; Wan, Zhen-Hua; Ma, Dong-Jun; Sun, De-Jun

    2016-07-01

    The flow instabilities of Rayleigh-Bénard convection in a cylinder with effect of uniform internal heat source are investigated numerically. The instabilities of the static state and of axisymmetric flows are investigated by linear stability analysis. The convection threshold depends on the strength of internal heat source q and the aspect ratio of the cylinder Γ. The stability of axisymmetric flows is strongly affected by these two parameters, as well as the Prandtl number Pr. Depending on the value of q, three regimes are identified: weak internal heating, moderate internal heating, and strong internal heating regime. In a weak internal heating regime, the instability characteristics are similar to Rayleigh-Bénard convection. In a moderate internal heating regime, intense interaction of buoyancy instability and hydrodynamic instability result in complex instability curves. When q is large enough, the internal heating effect overwhelms the boundary heating effect. Specifically, the influence of Pr on instability is studied at a moderate internal heat strength q=6.4. An extremely multivalued stability curve is observed. At most five critical Rayleigh numbers can be determined for the axisymmetry-breaking instability at a certain Prandtl number. An axisymmetric unsteady instability mode is observed as well. By nonlinear simulation, the oscillatory flow patterns are obtained, and the axisymmetry-breaking bifurcation of the unsteady toroidal flow is studied. PMID:27575218

  6. Interactions of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments. Interim summary

    SciTech Connect

    Patterson, J.H.; Steinkruger, F.J.; Matlack, G.M.

    1980-09-01

    Observations and some conclusions made of the interactions of /sup 238/PuO/sub 2/ heat sources with terrestrial and aquatic environments may be used in predicting heat source behavior in the event of contact of these heat sources with land or ocean and in assessing the risk to the environment. These studies indicate that plutonium transport from the heat sources is mostly a physical process involving the movement of extremely fine particles rather than the chemical migration of plutonium ions.

  7. Technology Solutions Case Study: Ground Source Heat Pump Research, TaC Studios Residence, Atlanta, Georigia

    SciTech Connect

    2014-09-01

    This case study describes the construction of a new test home that demonstrates current best practices for the mixed-humid climate, including a high performance ground source heat pump for heating and cooling, a building envelope featuring advanced air sealing details and low-density spray foam insulation, and glazing that exceeds ENERGY STAR requirements.

  8. Differential turbulent heating of different ions in electron cyclotron resonance ion source plasma

    SciTech Connect

    Elizarov, L.I.; Ivanov, A.A.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-03-15

    The article considers the collisionless ion sound turbulent heating of different ions in an electron cyclotron resonance ion source (ECRIS). The ion sound arises due to parametric instability of pumping wave propagating along the magnetic field with the frequency close to that of electron cyclotron. Within the framework of turbulent heating model the different ions temperatures are calculated in gas-mixing ECRIS plasma.

  9. Foundation heat exchangers for residential ground source heat pump systems Numerical modeling and experimental validation

    SciTech Connect

    Xing, Lu; Cullin, James; Spitler, Jeffery; Im, Piljae; Fisher, Daniel

    2011-01-01

    A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

  10. Thermohydraulic testing of a helium heated steam-generator

    SciTech Connect

    Bezlepkin, V.V.; Korotayev, O.I.; Simkin, B.P.; Fedorovich, Y.D.; Mizonov, N.V.

    1990-01-01

    This paper presents an analysis of the results of testing an experimental steam-generator. The reasons for the deviation of the characteristics of the section from the predicted values are revealed. The results of an investigation into the gasdynamics of the inlet chamber of the experimental section are presented.

  11. Internal Heat Source in Thermoelastic Microelongated Solid Under Green Lindsay Theory

    NASA Astrophysics Data System (ADS)

    Ailawalia, Praveen; Kumar, Sunil; Pathania, Devinder Singh

    2016-06-01

    The present study deals with two dimensional deformation, due to internal heat source in a thermoelastic microelongated solid. A mechanical force is applied along the interface of elastic half space and thermoelastic microelongated half space. The problem is in the context of Green Lindsay (GL) theory. The analytic expressions for displacement component, normal force stress, temperature distribution and microelongation have been derived. The effect of internal heat source and microelongation on the derived components have been depicted graphically.

  12. Investigation of runoff generation from anthropogenic sources with dissolved xenobiotics

    NASA Astrophysics Data System (ADS)

    Krein, A.; Pailler, J.; Guignard, C.; Iffly, J.; Pfister, L.; Hoffmann, L.

    2009-04-01

    In the experimental Mess basin (35 km2, Luxembourg) dissolved xenobiotics in surface water are used to study the influences of anthropogenic sources like separated sewer systems on runoff generation. Emerging contaminants like pharmaceuticals are of growing interest because of their use in large quantities in human and veterinary medicine. The amounts reaching surface waters depend on rainfall patterns, hydraulic conditions, consumption, metabolism, degradation, and disposal. The behaviour of endocrine disruptors including pharmaceuticals in the aquatic environment is widely unknown. The twelve molecules analyzed belong to three families: the estrogens, the antibiotics (sulfonamides, tetracyclines), and the painkillers (ibuprofen, diclofenac). Xenobiotics can be used as potential environmental tracers for untreated sewerage. Our results show that the concentrations are highly variable during flood events. The highest concentrations are reached in the first flush period, mainly during the rising limb of the flood hydrographs. As a result of the kinematic wave effect the concentration peak occurs in some cases a few hours after the discharge maximum. In floodwater (eleven floods, 66 samples) the highest concentrations were measured for ibuprofen (g/l range), estrone, and diclofenac (all ng/l range). From the tetracycline group, essentially tetracycline itself is of relevance, while the sulfonamides are mainly represented by sulfamethoxazole (all in ng/l range). In the Mess River the pharmaceuticals fluxes during flood events proved to be influenced by hydrological conditions. Different pharmaceuticals showed their concentration peaks during different times of a flood event. An example is the estrone peak that - during summer flash floods - often occurred one to two hours prior to the largest concentrations of the painkillers. This suggests for more sources than the sole storm drainage through the spillway of the single sewage water treatment plant, different

  13. Generation of high charge state metal ion beams by electron cyclotron resonance heating of vacuum arc plasma in cusp trap

    SciTech Connect

    Nikolaev, A. G.; Savkin, K. P.; Oks, E. M.; Vizir, A. V.; Yushkov, G. Yu.; Vodopyanov, A. V.; Izotov, I. V.; Mansfeld, D. A.

    2012-02-15

    A method for generating high charge state heavy metal ion beams based on high power microwave heating of vacuum arc plasma confined in a magnetic trap under electron cyclotron resonance conditions has been developed. A feature of the work described here is the use of a cusp magnetic field with inherent ''minimum-B'' structure as the confinement geometry, as opposed to a simple mirror device as we have reported on previously. The cusp configuration has been successfully used for microwave heating of gas discharge plasma and extraction from the plasma of highly charged, high current, gaseous ion beams. Now we use the trap for heavy metal ion beam generation. Two different approaches were used for injecting the vacuum arc metal plasma into the trap - axial injection from a miniature arc source located on-axis near the microwave window, and radial injection from sources mounted radially at the midplane of the trap. Here, we describe preliminary results of heating vacuum arc plasma in a cusp magnetic trap by pulsed (400 {mu}s) high power (up to 100 kW) microwave radiation at 37.5 GHz for the generation of highly charged heavy metal ion beams.

  14. Heat generation by electronic current in a quantum dot spin-valve

    SciTech Connect

    Chi, Feng; Sun, Lian-Liang; Guo, Yu

    2014-10-28

    Electric-current-induced heat generation in an interacting single-level quantum dot connected to ferromagnetic leads with noncollinear magnetizations is theoretically investigated. We find that when the two leads' spin polarization rates are identical and much smaller than unit, the magnitude of the heat generation is almost monotonously enhanced as the angle between the leads' magnetic moments is varied from zero to π, while the magnitude of the electric current is continuously suppressed. Moreover, the properties of the heat generation depend on the lead's spin polarization rate in different ways when the angle is varied. If at least one of the leads' spin polarization rate approaches to unit, the spin-valve effect of the heat generation is identical to that of the electric current. Now the previously found negative differential of the heat generation disappears when the angle approaches to π. As compared to the current, the heat generation is more sensitive to the system's asymmetry when one of the electrodes is half-metallic in noncollinear configurations.

  15. Production of general purpose heat source (GPHS) using advanced manufacturing methods

    NASA Astrophysics Data System (ADS)

    Miller, Roger G.

    1996-03-01

    Mankind will continue to explore the stars through the use of unmanned space craft until the technology and costs are compatible with sending travelers to the outer planets of our solar system and beyond. Unmanned probes of the present and future will be necessary to develop the necessary technologies and obtain information that will make this travel possible. Because of the significant costs incurred, the use of modern manufacturing technologies must be used to lower the investment needed even when shared by international partnerships. For over the last 30 years, radioisotopes have provided the heat from which electrical power is extracted. Electric power for future spacecraft will be provided by either Radioisotope Thermoelectric Generators (RTG), Radioisotopic Thermophotovoltaic systems (RTPV), radioisotope Stirling systems, or a combination of these. All of these systems will be thermally driven by General Purpose Heat Source (GPHS) fueled clad in some configuration. The GPHS clad contains a 238PuO2 pellet encapsulated in an iridium alloy container. Historically, the fabrication of the iridium alloy shells has been performed at EG&G Mound and Oak Ridge National Laboratory (ORNL), and girth welding at Westinghouse Savannah River Corporation (WSRC) and Los Alamos National Laboratory (LANL). This paper will describe the use of laser processing for welding, drilling, cutting, and machining with other manufacturing methods to reduce the costs of producing GPHS fueled clad components and compléted assemblies. Incorporation of new quality technologies will compliment these manufacturing methods to reduce cost.

  16. Solar Jets as Sources of Outflows, Heating and Waves

    NASA Astrophysics Data System (ADS)

    Nishizuka, N.

    2013-05-01

    Recent space solar observations of the Sun, such as Hinode and SDO, have revealed that magnetic reconnection is ubiquitous in the solar atmosphere, ranging from small scale reconnection (observed as nanoflares) to large scale one (observed as long duration flares or giant arcades). Especially recent Hinode observations has found various types of tiny chromospheric jets, such as chromospheric anemone jets, penumbral microjets and light bridge jets from sunspot umbra. It was also found that the corona is full of tiny X-ray jets. Often they are seen as helical spinning jets with Alfvenic waves in the corona. Sometimes they are seen as chromospheric jets with slow-mode magnetoacoustic waves and sometimes as unresolved jet-like events at the footpoint of recurrent outflows and waves at the edge of the active region. There is increasing evidence of magnetic reconnection in these tiny jets and its association with waves. The origin of outflows and waves is one of the issues concerning coronal heating and solar wind acceleration. To answer this question, we had a challenge to reproduce solar jets with laboratory plasma experiment and directly measured outflows and waves. As a result, we could find a propagating wave excited by magnetic reconnection, whose energy flux is 10% of the released magnetic energy. That is enough for solar wind acceleration and locally enough for coronal heating, consistent with numerical MHD simulations of solar jets. Here we would discuss recent observations with Hinode, theories and experimental results related to jets and waves by magnetic reconnection, and discuss possible implication to reconnection physics, coronal heating and solar wind acceleration.

  17. Generation of Whistler Wave by a Rotating Magnetic Field Source

    NASA Astrophysics Data System (ADS)

    Karavaev, A.; Papadopoulos, K.; Shao, X.; Sharma, A. S.; Gigliotti, A.; Gekelman, W.; Pribyl, P.; Vincena, S.

    2008-12-01

    The interaction of Rotating Magnetic Fields (RMF) with plasmas is a fundamental plasma physics problem with implications to fusion related Field-Reversed Configurations (FRC), space propulsion, astronaut protection from cosmic rays in long interstellar travel, control of the energetic population in the radiation belts and near zone processes in pulsar magnetospheres. In this paper we report recent experiments on the generation of whistler waves with a new type RMF-based antenna. The experiments were conducted on UCLA's Large Plasma Device (LAPD). The Rotating Magnetic Field (RMF) is created using poly-phased loop antennas. A number of parameter combinations, e.g. plasma density, background magnetic field, and driving current, were used. It was found that RMF created by a two phase-delayed loop antenna drives significant currents along the ambient magnetic field. The measured amplitude of induced wave field was proportional to the square-root of the plasma density. The spatial decay rate for the wave perturbation across the background magnetic field was found to scale with the plasma skin depth. A small amplitude second harmonic was also measured. The paper will also present analytic and simulation results that account for the experimental results; in particular, the scaling of the induced magnetic field as a function of the RMF and plasma parameters and the spatial decay rate of magnetic field. Applications of RMF as an efficient radiation source of plasma waves in space plasmas will be discussed. This work was sponsored by ONR MURI Grant 5-28828

  18. Spatio-temporal Variability in Midwinter Snowmelt Generated by Ground Heat Flux: Implications for Catchment Hydrology

    NASA Astrophysics Data System (ADS)

    Smith, R. S.; Moore, R. D.; Weiler, M.

    2008-12-01

    Ground heat flux is commonly ignored in the modelling of snowpack energy exchanges and snowmelt runoff due to its perceived insignificance relative to other energy sources. Snowmelt at the base of a snowpack was continuously measured during the winters of 2006/07 and 2007/08 with 4 m2 lysimeters at six sites within a 3.5 km2 continental, mountainous catchment in southeast British Columbia. Soil wetness and soil, air, and snow temperatures were also continuously measured at each site. During the 2006/07 winter season, accumulated snowmelt during a three month midwinter period with sub- zero air temperatures ranged from 11 to 107 mm, comprising 3 to 36 % as much as the annual peak snow water accumulation. Daily snowmelt regularly exceeded 1 mm at several sites while daily maximum air temperatures were well below 0°C suggesting that ground heat flux generated the midwinter snowmelt (i.e. ground melt). Temporal variability of melt was strongly associated with air temperature, even at sub-zero temperatures. Spatial variability of melt was strongly associated with soil wetness, and wetness levels at wetter sites were maintained or increased through ground melt inputs. During the 2007/08 midwinter period, accumulated ground melt did not exceed 10 mm due to extensive soil freezing prior to snowpack development. The results suggest that a positive feedback response loop exists between soil wetness, ground heat flux, and ground melt due to the association between soil thermal conductivity and soil wetness. Pre-winter soil wetness and soil temperature, and winter meteorology influence the amount of midwinter ground melt because they control the relative amounts of ground heat flux that are used for melt, soil warming, or snowpack heat conduction. Pre-winter soil hydro-thermal dynamics and midwinter ground melt might be important controls on the spatial pattern of winter/spring catchment wetness and subsequent runoff response if antecedent soil conditions and ground melt

  19. Natural convective heat and mass transfer in a porous triangular enclosure filled with nanofluid in presence of heat generation

    NASA Astrophysics Data System (ADS)

    Chowdhury, Raju; Parvin, Salma; Khan, Md. Abdul Hakim

    2016-07-01

    The problem of natural convective heat and mass transfer in a triangular enclosure filled with nanofluid saturated porous medium in presence of heat generation has been studied in this paper. The bottom wall of the cavity is heated uniformly, the left inclined wall is heated linearly and the right inclined wall is considered to be cold. The concentration is higher at bottom wall, lower at right inclined wall and linearly concentrated at left inclined wall of the cavity. The governing equations are transformed to the dimensionless form and solved numerically using Galerkin weighted residual technique of finite element method. The results are obtained in terms of streamline, isotherms, isoconcentrations, Nusselt number (Nu) and Sherwood number (Sh) for the parameters thermal Rayleigh number (RaT), Heat generation parameter (λ) and Lewis number (Le) while Prandtl number (Pr), Buoyancy ratio (N) and Darcy number (Da) are considered to be fixed. It is observed that flow pattern, temperature fields and concentration fields are affected by the variation of above considered parameters.

  20. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    SciTech Connect

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01

    With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.

  1. Heat transfer enhancement -- the maturing of second-generation heat transfer technology

    SciTech Connect

    Bergles, A.E.

    1997-01-01

    This paper is basically the text of the Kern Lecture for 1991 (the 1990 Kern Award). The paper begins with some remarks about Dr. Kern. By way of introduction to heat transfer enhancement, historical notes and the evolution of literature in this area are presented. Comments are made about the increasing practical applications of enhancement technology. Developments in single-phase convection are presented, with particular emphasis on offset strip fins and twisted-tape inserts. Pool boiling and flow boiling (particularly microfin tubes) are then considered in some detail. It is concluded that enhancement represents a powerful technology to improve heat exchanger performance.

  2. Parametric numerical investigaion of natural convection in a heat-generating fluid with phase transitions

    SciTech Connect

    Aksenova, A.E.; Chudanov, V.V.; Strizhov, V.F.; Vabishchevich, P.N.

    1995-09-01

    Unsteady natural convection of a heat-generating fluid with phase transitions in the enclosures of a square section with isothermal rigid walls is investigated numerically for a wide range of dimensionless parameters. The quasisteady state solutions of conjugate heat and mass transfer problem are compared with available experimental results. Correlation relations for heat flux distributions at the domain boundaries depending on Rayleigh and Ostrogradskii numbers are obtained. It is shown that generally heat transfer is governed both by natural circulation and crust formation phenomena. Results of this paper may be used for analysis of experiments with prototypic core materials.

  3. Compound heat transfer enhancement for shell side of double-pipe heat exchanger by helical fins and vortex generators

    NASA Astrophysics Data System (ADS)

    Zhang, Li; Guo, Hongmei; Wu, Jianhua; Du, Wenjuan

    2012-07-01

    To improve heat transfer performance of shell side of double-pipe heat exchanger with helical fins on its inner tube, some vortex generators (VGs) were installed along the centerline of the helical channel. Heat transfer performance and pressure drop characteristic of the enhanced heat exchangers were investigated using air as the working fluid and steam as the heating medium. The helical fins were in the annulus and span its full width at different helical pitch. Wing-type VGs (delta or rectangular wing) and winglet-type VGs (delta or rectangular winglet pair) were used to combine with helical fins. The friction factor and Nusselt number can be well correlated by power-law correlations in the Reynolds number range studied. In order to evaluate the thermal performance of the shell side enhanced over the shell side without enhancement, comparisons were made under three constraints: (1) identical mass flow rate, IMF; (2) identical pressure drop, IPD and (3) identical pumping power, IPP. The results show the shell side enhanced by the compound heat transfer enhancement has better performance than the shell side only enhanced by helical fins at shorter helical pitch under the three constraints.

  4. MHD natural convection flow along a vertical wavy surface with heat generation and pressure work

    NASA Astrophysics Data System (ADS)

    Alim, M. A.; Kabir, K. H.; Andallah, L. S.

    2016-07-01

    In this paper, the influence of pressure work on MHD natural convection flow of viscous incompressible fluid along a uniformly heated vertical wavy surface with heat generation has been investigated. The governing boundary layer equations are first transformed into a non-dimensional form using suitable set of dimensionless variables. The resulting nonlinear system of partial differential equations are mapped into the domain of a vertical flat plate and then solved numerically employing the implicit finite difference method, known as Keller-box scheme. The numerical results for the velocity profiles, temperature profiles, skin friction coefficient, the rate of heat transfers, the streamlines and the isotherms are shown graphically and skin friction coefficient and rate of heat transfer have been shown in tabular form for different values of the selective set of parameters consisting of pressure work parameter Ge, the magnetic parameter M, Prandtl number Pr, heat generation parameter Q and the amplitude of the wavy surface.

  5. Method and apparatus for enhanced heat recovery from steam generators and water heaters

    DOEpatents

    Knight, Richard A.; Rabovitser, Iosif K.; Wang, Dexin

    2006-06-27

    A heating system having a steam generator or water heater, at least one economizer, at least one condenser and at least one oxidant heater arranged in a manner so as to reduce the temperature and humidity of the exhaust gas (flue gas) stream and recover a major portion of the associated sensible and latent heat. The recovered heat is returned to the steam generator or water heater so as to increase the quantity of steam generated or water heated per quantity of fuel consumed. In addition, a portion of the water vapor produced by combustion of fuel is reclaimed for use as feed water, thereby reducing the make-up water requirement for the system.

  6. Encouragement of Enzyme Reaction Utilizing Heat Generation from Ferromagnetic Particles Subjected to an AC Magnetic Field

    PubMed Central

    Suzuki, Masashi; Aki, Atsushi; Mizuki, Toru; Maekawa, Toru; Usami, Ron; Morimoto, Hisao

    2015-01-01

    We propose a method of activating an enzyme utilizing heat generation from ferromagnetic particles under an ac magnetic field. We immobilize α-amylase on the surface of ferromagnetic particles and analyze its activity. We find that when α-amylase/ferromagnetic particle hybrids, that is, ferromagnetic particles, on which α-amylase molecules are immobilized, are subjected to an ac magnetic field, the particles generate heat and as a result, α-amylase on the particles is heated up and activated. We next prepare a solution, in which α-amylase/ferromagnetic particle hybrids and free, nonimmobilized chitinase are dispersed, and analyze their activities. We find that when the solution is subjected to an ac magnetic field, the activity of α-amylase immobilized on the particles increases, whereas that of free chitinase hardly changes; in other words, only α-amylase immobilized on the particles is selectively activated due to heat generation from the particles. PMID:25993268

  7. Encouragement of Enzyme Reaction Utilizing Heat Generation from Ferromagnetic Particles Subjected to an AC Magnetic Field.

    PubMed

    Suzuki, Masashi; Aki, Atsushi; Mizuki, Toru; Maekawa, Toru; Usami, Ron; Morimoto, Hisao

    2015-01-01

    We propose a method of activating an enzyme utilizing heat generation from ferromagnetic particles under an ac magnetic field. We immobilize α-amylase on the surface of ferromagnetic particles and analyze its activity. We find that when α-amylase/ferromagnetic particle hybrids, that is, ferromagnetic particles, on which α-amylase molecules are immobilized, are subjected to an ac magnetic field, the particles generate heat and as a result, α-amylase on the particles is heated up and activated. We next prepare a solution, in which α-amylase/ferromagnetic particle hybrids and free, nonimmobilized chitinase are dispersed, and analyze their activities. We find that when the solution is subjected to an ac magnetic field, the activity of α-amylase immobilized on the particles increases, whereas that of free chitinase hardly changes; in other words, only α-amylase immobilized on the particles is selectively activated due to heat generation from the particles.

  8. Experimental investigation on water quality standard of Yangtze River water source heat pump.

    PubMed

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

    Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source-sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps.

  9. Experimental investigation on water quality standard of Yangtze River water source heat pump.

    PubMed

    Qin, Zenghu; Tong, Mingwei; Kun, Lin

    2012-01-01

    Due to the surface water in the upper reaches of Yangtze River in China containing large amounts of silt and algae, high content of microorganisms and suspended solids, the water in Yangtze River cannot be used for cooling a heat pump directly. In this paper, the possibility of using Yangtze River, which goes through Chongqing, a city in southwest China, as a heat source-sink was investigated. Water temperature and quality of the Yangtze River in the Chongqing area were analyzed and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally, and the water quality standards, in particular surface water conditions, in the Yangtze River region that adapt to energy-efficient heat pumps were also proposed. The experimental results show that the coefficient of performance heat pump falls by 3.73% to the greatest extent, and the fouling resistance of cooling water in the heat exchanger increases up to 25.6% in different water conditions. When the sediment concentration and the turbidity in the river water are no more than 100 g/m3 and 50 NTU respectively, the performance of the heat pump is better, which can be used as a suitable river water quality standard for river water source heat pumps. PMID:22797241

  10. Behavioral observations and operant procedures using microwaves as a heat source for young chicks

    SciTech Connect

    Morrison, W.D.; McMillan, I.; Bate, L.A.; Otten, L.; Pei, D.C.

    1986-08-01

    Four trials, using operant conditioning procedures, were conducted to study the response of chicks, housed at 16 C, to microwave or infrared heat. Microwave power density was 26 mW/cm2 in Trial 1, 13 mW/cm2 in Trial 2, and 10 mW/cm2 in Trials 3 and 4. Chicks voluntarily demanded between 28 and 63% as much heat (min heat/hr) from microwave source as from infrared source at all power densities. There was no correlation, however, between the ratio of heat demanded and the power density used. There were no significant differences in growth between infrared- or microwave-heated chicks. It is evident from these studies that 8-day-old broiler chicks are capable of associating the performance of a task with a thermal reward provided by the microwaves. They are also able to utilize these microwaves through operant conditioning without any visible detrimental effect to their health or behavior.

  11. Impact factors on the long-term sustainability of Borehole Heat Exchanger coupled Ground Source Heat Pump System

    NASA Astrophysics Data System (ADS)

    Shao, Haibing; Hein, Philipp; Görke, Uwe-Jens; Bucher, Anke; Kolditz, Olaf

    2016-04-01

    In recent years, Ground Source Heat Pump System (GSHPS) has been recognized as an efficient technology to utilize shallow geothermal energy. Along with its wide application, some GSHPS are experiencing a gradual decrease in Borehole Heat Exchanger (BHE) outflow temperatures and thus have to be turned off after couple of years' operation. A comprehensive numerical investigation was then performed to model the flow and heat transport processes in and around the BHE, together with the dynamic change of heat pump efficiency. The model parameters were based on the soil temperature and surface weather condition in the Leipzig area. Different scenarios were modelled for a service life of 30 years, to reveal the evolution of BHE outflow and surrounding soil temperatures. It is found that lateral groundwater flow and using BHE for cooling will be beneficial to the energy recovery, along with the efficiency improvement of the heat pump. In comparison to other factors, the soil heat capacity and thermal conductivity are considered to have minor impact on the long-term sustainability of the system. Furthermore, the application of thermally enhanced grout material will improve the sustainability and efficiency. In contrast, it is very likely that undersized systems and improper grouting are the causes of strong system degradation.

  12. STAR: The Secure Transportable Autonomous Reactor System - Encapsulated Fission Heat Source

    SciTech Connect

    Ehud Greenspan

    2003-10-31

    OAK-B135 The Encapsulated Nuclear Heat Source (ENHS) is a novel 125 MWth fast spectrum reactor concept that was selected by the 1999 DOE NERI program as a candidate ''Generation-IV'' reactor. It uses Pb-Bi or other liquid-metal coolant and is intended to be factory manufactured in large numbers to be economically competitive. It is anticipated to be most useful to developing countries. The US team studying the feasibility of the ENHS reactor concept consisted of the University of California, Berkeley, Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL) and Westinghouse. Collaborating with the US team were three Korean organizations: Korean Atomic Energy Research Institute (KAERI), Korean Advanced Institute for Science and Technology (KAIST) and the University of Seoul, as well as the Central Research Institute of the Electrical Power Industry (CRIEPI) of Japan. Unique features of the ENHS include at least 20 years of operation without refueling; no fuel handling in the host country; no pumps and valves; excess reactivity does not exceed 1$; fully passive removal of the decay heat; very small probability of core damaging accidents; autonomous operation and capability of load-following over a wide range; very long plant life. In addition it offers a close match between demand and supply, large tolerance to human errors, is likely to get public acceptance via demonstration of superb safety, lack of need for offsite response, and very good proliferation resistance. The ENHS reactor is designed to meet the requirements of Generation IV reactors including sustainable energy supply, low waste, high level of proliferation resistance, high level of safety and reliability, acceptable risk to capital and, hopefully, also competitive busbar cost of electricity.

  13. Next Generation Source Measuments: CRADA partner communication sheet

    EPA Science Inventory

    Partnerships to Advance Next Gen. Source MeasurementsA growing number of government, academic, and industry groups are recognizing the revolution in air pollution and greenhouse gas source measurement science enabled by the rapid advances in sensors, communications, data integrat...

  14. On the existence of another source of heat production for the earth and planets, and its connection with gravitomagnetism.

    PubMed

    Elbeze, Alexandre Chaloum

    2013-01-01

    Recent revised estimates of the Earth's surface heat flux are in the order of 47 TW. Given that its internal radiogenic (mantle and crust) heat production is estimated to be around 20 TW, the Earth has a thermal deficit of around 27 TW. This article will try to show that the action of the gravitational field of the Sun on the rotating masses of the Earth is probably the source of another heat production in order of 54TW, which would satisfy the thermal balance of our celestial body and probably explain the reduced heat flow Qo. We reach this conclusion within the framework of gravitation implied by Einstein's special and general relativity theory (SR, GR). Our results show that it might possible, in principle, to calculate the heat generated by the action of the gravitational field of celestial bodies on the Earth and planets of the Solar System (a phenomenon that is different to that of the gravitational tidal effect from the Sun and the Moon). This result should help physicists to improve and develop new models of the Earth's heat balance, and suggests that contrary to cooling, the Earth is in a phase of thermal balance, or even reheating. PMID:24255828

  15. On the existence of another source of heat production for the earth and planets, and its connection with gravitomagnetism.

    PubMed

    Elbeze, Alexandre Chaloum

    2013-01-01

    Recent revised estimates of the Earth's surface heat flux are in the order of 47 TW. Given that its internal radiogenic (mantle and crust) heat production is estimated to be around 20 TW, the Earth has a thermal deficit of around 27 TW. This article will try to show that the action of the gravitational field of the Sun on the rotating masses of the Earth is probably the source of another heat production in order of 54TW, which would satisfy the thermal balance of our celestial body and probably explain the reduced heat flow Qo. We reach this conclusion within the framework of gravitation implied by Einstein's special and general relativity theory (SR, GR). Our results show that it might possible, in principle, to calculate the heat generated by the action of the gravitational field of celestial bodies on the Earth and planets of the Solar System (a phenomenon that is different to that of the gravitational tidal effect from the Sun and the Moon). This result should help physicists to improve and develop new models of the Earth's heat balance, and suggests that contrary to cooling, the Earth is in a phase of thermal balance, or even reheating.

  16. Techno-economic analysis of renewable energy source options for a district heating project

    SciTech Connect

    Ghafghazi, S.; Sowlati, T.; Sokhansanj, Shahabaddine; Melin, Staffan

    2009-09-01

    With the increased interest in exploiting renewable energy sources for district heating applications, the economic comparison of viable options has been considered as an important step in making a sound decision. In this paper, the economic performance of several energy options for a district heating system in Vancouver, British Columbia, is studied. The considered district heating system includes a 10 MW peaking/ backup natural gas boiler to provide about 40% of the annual energy requirement and a 2.5 MW base-load system. The energy options for the base-load system include: wood pellet, sewer heat, and geothermal heat. Present values of initial and operating costs of each system were calculated over 25-year service life of the systems, considering depreciation and salvage as a negative cost item. It was shown that the wood pellet heat producing technologies provided less expensive energy followed by the sewer heat recovery, geothermal and natural gas systems. Among wood pellet technologies, the grate burner was a less expensive option than powder and gasifier technologies. It was found that using natural gas as a fuel source for the peaking/backup system accounted for more than 40% of the heat production cost for the considered district heating center. This is mainly due to the high natural gas prices which cause high operating costs over the service life of the district heating system. Variations in several economic inputs did not change the ranking of the technology options in the sensitivity analysis. However, it was found that the results were more sensitive to changes in operating costs of the system than changes in initial investment. It is economical to utilize wood pellet boilers to provide the base-load energy requirement of district heating systems Moreover, the current business approach to use natural gas systems for peaking and backup in district heating systems could increase the cost of heat production significantly.

  17. Chemical characteristics and source apportionment of atmospheric particles during heating period in Harbin, China.

    PubMed

    Huang, Likun; Wang, Guangzhi

    2014-12-01

    Atmospheric particles (total suspended particles (TSPs); particulate matter (PM) with particle size below 10 μm, PM10; particulate matter with particle size below 2.5 μm, PM(2.5)) were collected and analyzed during heating and non-heating periods in Harbin. The sources of PM10 and PM(2.5) were identified by the chemical mass balance (CMB) receptor model. Results indicated that PM(2.5)/TSP was the most prevalent and PM(2.5) was the main component of PM(10), while the presence of PM(10-100) was relatively weak. SO(4)(2-) and NO(3)(-) concentrations were more significant than other ions during the heating period. As compared with the non-heating period, Mn, Ni, Pb, S, Si, Ti, Zn, As, Ba, Cd, Cr, Fe and K were relatively higher during the heating period. In particular, Mn, Ni, S, Si, Ti, Zn and As in PM(2.5) were obviously higher during the heating period. Organic carbon (OC) in the heating period was 2-5 times higher than in the non-heating period. Elemental carbon (EC) did not change much. OC/EC ratios were 8-11 during the heating period, which was much higher than in other Chinese cities (OC/EC: 4-6). Results from the CMB indicated that 11 pollution sources were identified, of which traffic, coal combustion, secondary sulfate, secondary nitrate, and secondary organic carbon made the greatest contribution. Before the heating period, dust and petrochemical industry made a larger contribution. In the heating period, coal combustion and secondary sulfate were higher. After the heating period, dust and petrochemical industry were higher. Some hazardous components in PM(2.5) were higher than in PM(10), because PM(2.5) has a higher ability to absorb toxic substances. Thus PM(2.5) pollution is more significant regarding human health effects in the heating period.

  18. Preliminary design study of an alternate heat source assembly for a Brayton isotope power system

    NASA Technical Reports Server (NTRS)

    Strumpf, H. J.

    1978-01-01

    Results are presented for a study of the preliminary design of an alternate heat source assembly (HSA) intended for use in the Brayton isotope power system (BIPS). The BIPS converts thermal energy emitted by a radioactive heat source into electrical energy by means of a closed Brayton cycle. A heat source heat exchanger configuration was selected and optimized. The design consists of a 10 turn helically wound Hastelloy X tube. Thermal analyses were performed for various operating conditions to ensure that post impact containment shell (PICS) temperatures remain within specified limits. These limits are essentially satisfied for all modes of operation except for the emergency cooling system for which the PICS temperatures are too high. Neon was found to be the best choice for a fill gas for auxiliary cooling system operation. Low cycle fatigue life, natural frequency, and dynamic loading requirements can be met with minor modifications to the existing HSA.

  19. Wearable thermoelectric generator for harvesting human body heat energy

    NASA Astrophysics Data System (ADS)

    Kim, Min-Ki; Kim, Myoung-Soo; Lee, Seok; Kim, Chulki; Kim, Yong-Jun

    2014-10-01

    This paper presents the realization of a wearable thermoelectric generator (TEG) in fabric for use in clothing. A TEG was fabricated by dispenser printing of Bi0.5Sb1.5Te3 and Bi2Se0.3Te2.7 in a polymer-based fabric. The prototype consisted of 12 thermocouples connected by conductive thread over an area of 6 × 25 mm2. The device generated a power of 224 nW for a temperature difference of 15 K. When the TEG was used on the human body, the measured output power was 224 nW in an ambient temperature of 5 °C. The power of the TEG was affected by the movement of the wearer. A higher voltage was maintained while walking than in a stationary state. In addition, the device did not deform after it was bent and stretched several times. The prospect of using the TEG in clothing applications was confirmed under realistic conditions.

  20. COMPARATIVE STUDY AMONG HYBRID GROUND SOURCE HEAT PUMP SYSTEM, COMPLETE GROUND SOURCE HEAT PUMP AND CONVENTIONAL HVAC SYSTEM

    SciTech Connect

    Jiang Zhu; Yong X. Tao

    2011-11-01

    In this paper, a hotel with hybrid geothermal heat pump system (HyGSHP) in the Pensacola is selected and simulated by the transient simulation software package TRNSYS [1]. To verify the simulation results, the validations are conducted by using the monthly average entering water temperature, monthly facility consumption data, and etc. And three types of HVAC systems are compared based on the same building model and HVAC system capacity. The results are presented to show the advantages and disadvantages of HyGSHP compared with the other two systems in terms of energy consumptions, life cycle cost analysis.

  1. Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

    SciTech Connect

    Moyer, M.W.

    2001-01-11

    A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

  2. General-Purpose Heat Source Development: Safety Verification Test Program. Flyer plate test series

    SciTech Connect

    Cull, T.A.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of a radioisotope thermoelectric generator (RTG) that will provide electric power for space missions. The initial RTG applications will be for the NASA Galileo and the ESA Ulysses missions. Each of the 18 GPHS modules in an RTG contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) has been conducted to assess the ability of the GPHS fueled clads to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System Vehicle (space shuttle) is one conceivable accident, the SVT plan included a series of tests to simulate the fragment environment that the RTG and GPHS modules would experience in such an event. These tests deal specifically with the flat-on collision of flyer-plate-type fragments with bare, simulant-fueled (depleted UO/sub 2/) clads. Results of these tests suggest that the fueled clad is only minimally breached by collision with 3.53-mm-thick flyer-plate-type fragments of space shuttle alloy at velocities up to 1170 m/s. However, collision of a 38.1-mm-thick plate with a bare GPHS clad, at a velocity of 270 m/s, results in a total release of fuel.

  3. General-Purpose Heat Source development: Safety Verification Test Program. Bullet/fragment test series

    SciTech Connect

    George, T.G.; Tate, R.E.; Axler, K.M.

    1985-05-01

    The radioisotope thermoelectric generator (RTG) that will provide power for space missions contains 18 General-Purpose Heat Source (GPHS) modules. Each module contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. Because a launch-pad or post-launch explosion is always possible, we need to determine the ability of GPHS fueled clads within a module to survive fragment impact. The bullet/fragment test series, part of the Safety Verification Test Plan, was designed to provide information on clad response to impact by a compact, high-energy, aluminum-alloy fragment and to establish a threshold value of fragment energy required to breach the iridium cladding. Test results show that a velocity of 555 m/s (1820 ft/s) with an 18-g bullet is at or near the threshold value of fragment velocity that will cause a clad breach. Results also show that an exothermic Ir/Al reaction occurs if aluminum and hot iridium are in contact, a contact that is possible and most damaging to the clad within a narrow velocity range. The observed reactions between the iridium and the aluminum were studied in the laboratory and are reported in the Appendix.

  4. The Encapsulated Nuclear Heat Source for Proliferation-Resistant Low-Waste Nuclear Energy

    SciTech Connect

    Brown, N; Carelli, M; Conway, L; Dzodzo, M; Greenspan, E; Hossain, Q; Saphier, D; Shimada, H; Sienicki, J; Wade, D

    2001-04-01

    Encapsulated Nuclear Heat Source (ENHS) is a small innovative reactor suitable for use in developing countries. The reference design is a SOMWe lead-bismuth eutectic (Pb-Bi) cooled fast reactor. It is designed so that the fuel is installed and sealed into the reactor module at the factory. The nuclear controls, a major portion of the instrumentation and the Pb-Bi covering the core are also installed at the factory. At the site of operations the reactor module is inserted into a pool of Pb-Bi that contains the steam generators. Major components, such as the pool vessel and steam generators, are permanent and remain in place while the reactor module is replaced every 15 years. At the end of life the sealed reactor module is removed and returned to an internationally controlled recycling center. Thus, the ENHS provides a unique capability for ensuring the security of the nuclear fuel throughout its life. The design also can minimize the user country investment in nuclear technology and staff. Following operation and return of the module to the recycling facility, the useable components, including the fuel, are refurbished and available for reuse. A fuel cycle compatible with this approach has been identified that reduces the amount of nuclear waste.

  5. Heat flow, heat generation and crustal thermal structure of the northern block of the South Indian Craton

    NASA Technical Reports Server (NTRS)

    Gupta, Mohan L.; Sharma, S. R.; Sundar, A.

    1988-01-01

    Heat flow values and heat generation data calculated from the concentration of heat producing radioactive elements, U, Th and K in surface rocks were analyzed. The South Indian Craton according to Drury et al., can be divided into various blocks, separated by late Proterozoic shear belts. The northern block comprises Eastern and Western Dharwar Cratons of Rogers (1986), Naqvi and Rogers (1987) and a part of the South Indian granulite terrain up to a shear system occupying the Palghat-Cauvery low lands. The geothermal data analysis clearly demonstrates that the present thermal characteristics of the above two Archaean terrains of the Indian and Australian Shields are quite similar. Their crustal thermal structures are likely to be similar also.

  6. System and method for generating current by selective electron heating

    DOEpatents

    Fisch, Nathaniel J.; Boozer, Allen H.

    1984-01-01

    A system for the generation of toroidal current in a plasma which is prepared in a toroidal magnetic field. The system utilizes the injection of high-frequency waves into the plasma by means of waveguides. The wave frequency and polarization are chosen such that when the waveguides are tilted in a predetermined fashion, the wave energy is absorbed preferentially by electrons traveling in one toroidal direction. The absorption of energy in this manner produces a toroidal electric current even when the injected waves themselves do not have substantial toroidal momentum. This current can be continuously maintained at modest cost in power and may be used to confine the plasma. The system can operate efficiently on fusion grade tokamak plasmas.

  7. Properties and Applications of Laser Generated X-Ray Sources

    SciTech Connect

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  8. Membrane-based osmotic heat engine with organic solvent for enhanced power generation from low-grade heat.

    PubMed

    Shaulsky, Evyatar; Boo, Chanhee; Lin, Shihong; Elimelech, Menachem

    2015-05-01

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl-methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl-water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher OHE energy efficiency with the LiCl-methanol draw solution compared to that with the LiCl-water draw solution under practical operating conditions (i.e., heat recovery<90%). We discuss the implications of the results for converting low-grade heat to power. PMID:25839239

  9. Membrane-Based Osmotic Heat Engine with Organic Solvent for Enhanced Power Generation from Low-Grade Heat

    SciTech Connect

    Shaulsky, E; Boo, C; Lin, SH; Elimelech, M

    2015-05-05

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher ORE energy efficiency with the LiCl methanol draw solution compared to that with the LiCl water draw solution under practical operating conditions (i.e., heat recovery <90%). We discuss the implications of the results for converting low-grade heat to power.

  10. Membrane-based osmotic heat engine with organic solvent for enhanced power generation from low-grade heat.

    PubMed

    Shaulsky, Evyatar; Boo, Chanhee; Lin, Shihong; Elimelech, Menachem

    2015-05-01

    We present a hybrid osmotic heat engine (OHE) system that uses draw solutions with an organic solvent for enhanced thermal separation efficiency. The hybrid OHE system produces sustainable energy by combining pressure-retarded osmosis (PRO) as a power generation stage and membrane distillation (MD) utilizing low-grade heat as a separation stage. While previous OHE systems employed aqueous electrolyte draw solutions, using methanol as a solvent is advantageous because methanol is highly volatile and has a lower heat capacity and enthalpy of vaporization than water. Hence, the thermal separation efficiency of a draw solution with methanol would be higher than that of an aqueous draw solution. In this study, we evaluated the performance of LiCl-methanol as a potential draw solution for a PRO-MD hybrid OHE system. The membrane transport properties as well as performance with LiCl-methanol draw solution were evaluated using thin-film composite (TFC) PRO membranes and compared to the results obtained with a LiCl-water draw solution. Experimental PRO methanol flux and maximum projected power density of 47.1 L m(-2) h(-1) and 72.1 W m(-2), respectively, were achieved with a 3 M LiCl-methanol draw solution. The overall efficiency of the hybrid OHE system was modeled by coupling the mass and energy flows between the thermal separation (MD) and power generation (PRO) stages under conditions with and without heat recovery. The modeling results demonstrate higher OHE energy efficiency with the LiCl-methanol draw solution compared to that with the LiCl-water draw solution under practical operating conditions (i.e., heat recovery<90%). We discuss the implications of the results for converting low-grade heat to power.

  11. Solar power generation by use of Stirling engine and heat loss analysis of its cavity receiver

    NASA Astrophysics Data System (ADS)

    Hussain, Tassawar

    Since concentrated power generation by Stirling engine has the highest efficiency therefore efficient power generation by concentrated systems using a Stirling engine was a primary motive of this research. A 1 kW Stirling engine was used to generate solar power using a Fresnel lens as a concentrator. Before operating On-Sun test, engine's performance test was conducted by combustion test. Propane gas with air was used to provide input heat to the Stirling Engine and 350W power was generated with 14% efficiency of the engine. Two kinds of receivers were used for On-Sun test, first type was the Inconel tubes with trapped helium gas and the second one was the heat pipe. Heat pipe with sodium as a working fluid is considered the best approach to transfer the uniform heat from the receiver to the helium gas in the heater head of the engine. A Number of On-Sun experiments were performed to generate the power. A minimum 1kW input power was required to generate power from the Stirling engine but it was concluded that the available Fresnel lens was not enough to provide sufficient input to the Stirling engine and hence engine was lagged to generate the solar power. Later on, for a high energy input a Beam Down system was also used to concentrate the solar light on the heater head of the Stirling engine. Beam down solar system in Masdar City UAE, constructed in 2009 is a variation of central receiver plant with cassegrainian optics. Around 1.5kW heat input was achieved from the Beam Down System and it was predicted that the engine receiver at beam down has the significant heat losses of about 900W. These high heat losses were the major hurdles to get the operating temperature (973K) of the heat pipes; hence power could not be generated even during the Beam Down test. Experiments were also performed to find the most suitable Cavity Receiver configuration for maximum solar radiation utilizations by engine receiver. Dimensionless parameter aperture ration (AR=d/D) and aperture

  12. An inductively heated hot cavity catcher laser ion source

    SciTech Connect

    Reponen, M.; Moore, I. D. Pohjalainen, I.; Savonen, M.; Voss, A.; Rothe, S.; Sonnenschein, V.

    2015-12-15

    An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Ag isotopes. A proof-of-principle experiment has been realized by implanting primary {sup 107}Ag{sup 21+} ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z {sup 94}Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization scheme. Following mass separation, the ions were identified by scanning the frequency of the first resonant excitation step while recording the ion count rate. Ion release time profiles were measured for different implantation depths and cavity temperatures with the mean delay time varying from 10 to 600 ms. In addition, the diffusion coefficients for silver in graphite were measured for temperatures of 1470 K, 1630 K, and 1720 K, from which an activation energy of 3.2 ± 0.3 eV could be determined.

  13. An inductively heated hot cavity catcher laser ion source.

    PubMed

    Reponen, M; Moore, I D; Pohjalainen, I; Rothe, S; Savonen, M; Sonnenschein, V; Voss, A

    2015-12-01

    An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Ag isotopes. A proof-of-principle experiment has been realized by implanting primary (107)Ag(21+) ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z (94)Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization scheme. Following mass separation, the ions were identified by scanning the frequency of the first resonant excitation step while recording the ion count rate. Ion release time profiles were measured for different implantation depths and cavity temperatures with the mean delay time varying from 10 to 600 ms. In addition, the diffusion coefficients for silver in graphite were measured for temperatures of 1470 K, 1630 K, and 1720 K, from which an activation energy of 3.2 ± 0.3 eV could be determined. PMID:26724021

  14. An inductively heated hot cavity catcher laser ion source

    NASA Astrophysics Data System (ADS)

    Reponen, M.; Moore, I. D.; Pohjalainen, I.; Rothe, S.; Savonen, M.; Sonnenschein, V.; Voss, A.

    2015-12-01

    An inductively heated hot cavity catcher has been constructed for the production of low-energy ion beams of exotic, neutron-deficient Ag isotopes. A proof-of-principle experiment has been realized by implanting primary 107Ag21+ ions from a heavy-ion cyclotron into a graphite catcher. A variable-thickness nickel foil was used to degrade the energy of the primary beam in order to mimic the implantation depth expected from the heavy-ion fusion-evaporation recoils of N = Z 94Ag. Following implantation, the silver atoms diffused out of the graphite and effused into the catcher cavity and transfer tube, where they were resonantly laser ionized using a three-step excitation and ionization scheme. Following mass separation, the ions were identified by scanning the frequency of the first resonant excitation step while recording the ion count rate. Ion release time profiles were measured for different implantation depths and cavity temperatures with the mean delay time varying from 10 to 600 ms. In addition, the diffusion coefficients for silver in graphite were measured for temperatures of 1470 K, 1630 K, and 1720 K, from which an activation energy of 3.2 ± 0.3 eV could be determined.

  15. Design Option of Heat Exchanger for the Next Generation Nuclear Plant

    SciTech Connect

    Eung Soo Kim; Chang Oh

    2008-09-01

    The Next Generation Nuclear Plant (NGNP), a very High temperature Gas-Cooled Reactor (VHTGRS) concept, will provide the first demonstration of a closed-loop Brayton cycle at a commercial scale of a few hundred megawatts electric and hydrogen production. The power conversion system (PCS) for the NGNP will take advantage of the significantly higher reactor outlet temperatures of the VHTGRS to provide higher efficiencies than can be achieved in the current generation of light water reactors. Besides demonstrating a system design that can be used directly for subsequent commercial deployment, the NGNP will demonstrate key technology elements that can be used in subsequent advanced power conversion systems for other Generation IV reactors. In anticipation of the design, development and procurement of an advanced power conversion system for the NGNP, the system integration of the NGNP and hydrogen plant was initiated to identify the important design and technology options that must be considered in evaluating the performance of the proposed NGNP. As part of the system integration of the VHTGRS and hydrogen production plant, the intermediate heat exchanger is used to transfer the process heat from VHTGRS to hydrogen plant. Therefore, the design and configuration of the intermediate heat exchanger are very important. This paper will include analysis of one stage versus two stage heat exchanger design configurations and thermal stress analyses of a printed circuit heat exchanger, helical coil heat exchanger, and shell/tube heat exchanger.

  16. Heat transfer enhancement downstream of vortex generators on a flat plate

    SciTech Connect

    Turk, A.Y.

    1984-01-01

    This investigation was conducted in order to better understand the augmentation of forced convective heat transfer when a single row of counter-rotating vortex blades is attached to a flat surface. The major emphasis of the work is to study the way in which vortex generators augment the heat transfer coefficient of an initially-laminar boundary layer over a flat, constant heat flux surface exposed to favorable free stream pressure gradients. Particular emphasis is placed on the relationship between the geometry of vortex generators and the augmentation of local and overall heat transfer coefficients. The behavior of the boundary layer downstream of vortex generators is partially explored. This dissertation includes results of an experimental investigation that indicates the amount of heat transfer enhancement depends on the vortex blade height and arrangement on the plate surface. The local enhancement of the heat transfer coefficient was increased up to 300% over that for a plain flat plate mainly because of high turbulence produced over the region adjacent to the plate surface, resulting in increased mixing of the slower fluid near the plate surface with the free stream. A set of guidelines for the design of more efficient surface with vortex generators was proposed.

  17. Helium, heat, and the generation of hydrothermal event plumes at mid-ocean ridges

    NASA Astrophysics Data System (ADS)

    Lupton, John E.; Baker, Edward T.; Massoth, Gary J.

    1999-09-01

    Hydrothermal event plumes are unique water-column features observed over mid-ocean ridges, presumably generated by the sudden release of large volumes of hot, buoyant fluid. Although the specifics of event plume generation are unknown, event plumes have been attributed to the rapid emptying of a hydrothermal reservoir or to rapid heat extraction from a recently emplaced dike or seafloor lava flows. The chemical and thermal signatures of event plumes as compared to the underlying steady-state plumes offer important clues to the generation of event plumes. Event plumes have low 3He/heat ratios of ˜0.4 × 10-17 mol J-1, similar to vent fluids from mature hydrothermal systems. In contrast, the steady-state plumes found beneath the event plumes have elevated and variable 3He/heat ratios of 2 to 5 × 10-17 mol J-1. Fluids collected directly over fresh lava flows have even higher 3He/heat ratios of 2 to 8 × 10-17 mol J-1, up to 30 times the event plume values. These disparate 3He/heat ratios place strong constraints on models of event plume generation, especially models which rely on heat extraction from seafloor eruptions. Published by Elsevier Science B.V.

  18. Evaluation of equivalent defect heat generation in carbon epoxy composite under powerful ultrasonic stimulation by using infrared thermography

    NASA Astrophysics Data System (ADS)

    Derusova, D. A.; Vavilov, V. P.; Pawar, S. S.

    2015-04-01

    Low velocity impact is a frequently observed event during the operation of an aircraft composite structure. This type of damage is aptly called as “blind-side impact damage” as it is barely visible as a dent on the impacted surface, but may produce extended delaminations closer to the rear surface. One-sided thermal nondestructive testing is considered as a promising technique for detecting impact damage but because of diffusive nature of optical thermal signals there is drop in detectability of deeper subsurface defects. Ultrasonic Infrared thermography is a potentially attractive nondestructive evaluation technique used to detect the defects through observation of vibration-induced heat generation. Evaluation of the energy released by such defects is a challenging task. In this study, the thin delaminations caused by impact damage in composites and which are subjected to ultrasonic excitation are considered as local heat sources. The actual impact damage in a carbon epoxy composite which was detected by applying a magnetostrictive ultrasonic device is then modeled as a pyramid-like defect with a set of delaminations acting as an air-filled heat sources. The temperature rise expected on the surface of the specimen was achieved by varying energy contribution from each delamination through trial and error. Finally, by comparing the experimental temperature elevations in defective area with the results of temperature simulations, we estimated the energy generated by each defect and defect power of impact damage as a whole. The results show good correlation between simulations and measurements, thus validating the simulation approach.

  19. Thermionic converter with differentially heated cesium-oxygen source and method of operation

    DOEpatents

    Rasor, Ned S.; Riley, David R.; Murray, Christopher S.; Geller, Clint B.

    2000-01-01

    A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.

  20. Thermionic converter with differentially heated cesium-oxygen source and method of operation

    SciTech Connect

    Rasor, N.S.; Riley, D.R.; Murray, C.S.; Geller, C.B.

    1998-12-01

    A thermionic converter having an emitter, a collector, and a source of cesium vapor is provided, wherein the source of cesium vapor is differentially heated so that said source has a hotter end and a cooler end, with cesium vapor evaporating from said hotter end into the space between the emitter and the collector and with cesium vapor condensing at said cooler end. The condensed cesium vapor migrates through a porous element from the cooler end to the hotter end.