Sample records for fuel property combustion

  1. Properties of air and combustion products of fuel with air

    NASA Technical Reports Server (NTRS)

    Poferl, D. J.; Svehla, R. A.

    1975-01-01

    Thermodynamic and transport properties have been calculated for air, the combustion products of natural gas and air, and combustion products of ASTM-A-1 jet fuel and air. Properties calculated include: ratio of specific heats, molecular weight, viscosity, specific heat, thermal conductivity, Prandtl number, and enthalpy.

  2. Combustion gas properties. 2: Natural gas fuel and dry air

    NASA Technical Reports Server (NTRS)

    Wear, J. D.; Jones, R. E.; Trout, A. M.; Mcbride, B. J.

    1985-01-01

    A series of computations has been made to produce the equilibrium temperature and gas composition for natural gas fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0. Only samples tables and figures are provided in this report. The complete set of tables and figures is provided on four microfiche films supplied with this report.

  3. Fuel property effects on engine combustion processes. Final report

    SciTech Connect

    Cernansky, N.P.; Miller, D.L.

    1995-04-27

    A major obstacle to improving spark ignition engine efficiency is the limitations on compression ratio imposed by tendency of hydrocarbon fuels to knock (autoignite). A research program investigated the knock problem in spark ignition engines. Objective was to understand low and intermediate temperature chemistry of combustion processes relevant to autoignition and knock and to determine fuel property effects. Experiments were conducted in an optically and physically accessible research engine, static reactor, and an atmospheric pressure flow reactor (APFR). Chemical kinetic models were developed for prediction of species evolution and autoignition behavior. The work provided insight into low and intermediate temperature chemistry prior to autoignition of n-butane, iso-butane, n-pentane, 1-pentene, n-heptane, iso-octane and some binary blends. Study of effects of ethers (MTBE, ETBE, TAME and DIPE ) and alcohols (methanol and ethanol) on the oxidation and autoignition of primary reference fuel (PRF) blends.

  4. Effects of Fuel Physical Properties on Diesel Engine Combustion Using Diesel and Bio-Diesel Fuels

    SciTech Connect

    Ra, Youngchul [ORNL; Reitz, Rolf [University of Wisconsin; McFarlane, Joanna [ORNL; Daw, C Stuart [ORNL

    2007-01-01

    A computational study is performed to investigate the effects of physical property on diesel engine combustion characteristics using bio-diesel fuels. Properties of typical bio-diesel fuels that were either calculated or measured are used in the study and the simulation results are compared with those of conventional diesel fuels. Sensitivity of the computational results to individual physical properties is also investigated, and the results can provide information for desirable characteristics of the blended fuels. The properties considered in this study include liquid density, vapor pressure, surface tension, liquid viscosity, liquid thermal conductivity, liquid specific heat, latent heat, vapor specific heat, vapor diffusion coefficient, vapor viscosity and vapor thermal conductivity. The results show significant effects of the fuel physical properties on ignition delay and burning rates at various engine operating conditions. It is seen that there is no single physical property that dominates differences of ignition delay between diesel and bio-diesel fuels. However, among the 11 properties considered in the study, the simulation results were found to be most sensitive to the liquid fuel density, vapor pressure and surface tension through their effects on the mixture preparation processes.

  5. Fuels for Advanced Combustion Engines Research Diesel Fuels: Analysis of Physical and Chemical Properties

    Microsoft Academic Search

    Tom Gallant; Jim Franz; Mikhail Alnajjar; John Morse Storey; Samuel Arthur Lewis Sr; Scott Sluder; William C Cannella; Craig Fairbridge; Darcy Hager; Heather Dettman; Jon Luecke; Matthew A. Ratcliff; Brad Zigler

    2009-01-01

    The CRC Fuels for Advanced Combustion Engines working group has worked to identify a matrix of research diesel fuels for use in advanced combustion research applications. Nine fuels were specified and formulated to investigate the effects of cetane number aromatic content and 90% distillation fraction. Standard ASTM analyses were performed on the fuels as well as GC\\/MS and \\/u1H\\/\\/u1\\/u3C NMR

  6. Combustion Gas Properties I-ASTM Jet a Fuel and Dry Air

    NASA Technical Reports Server (NTRS)

    Jones, R. E.; Trout, A. M.; Wear, J. D.; Mcbride, B. J.

    1984-01-01

    A series of computations was made to produce the equilibrium temperature and gas composition for ASTM jet A fuel and dry air. The computed tables and figures provide combustion gas property data for pressures from 0.5 to 50 atmospheres and equivalence ratios from 0 to 2.0.

  7. Effect of W/O Emulsion Fuel Properties on Spray Combustion

    NASA Astrophysics Data System (ADS)

    Ida, Tamio; Fuchihata, Manabu; Takeda, Shuuco

    This study proposes a realizable technology for an emulsion combustion method that can reduce environmental loading. This paper discusses the effect on spray combustion for W/O emulsion fuel properties with an added agent, and the ratio between water and emulsifier added to a liquid fuel. The addition of water or emulsifier to a liquid fuel affected the spray combustion by causing micro-explosions in the flame due to geometric changes in the sprayed flame and changes to the temperature distribution. Experimental results revealed that the flame length shortened by almost 40% upon the addition of the water. Furthermore, it was found that water was effective in enhancing combustion due to its promoting micro-explosions. Results also showed that when the emulsifier was added to the spray flame, the additive burned in the flame's wake, producing a bright red flame. The flame length was observed to be long as a result. The micro-explosion phenomenon, caused by emulsifier dosage differences, was observed using time-dependent images at a generated frequency and an explosion scale with a high-speed photography method. Results indicated that the micro-explosion phenomenon in the W/O emulsion combustion method effectively promoted the combustion reaction and suppressed soot formation.

  8. Properties of air and combustion products of fuels with air

    NASA Technical Reports Server (NTRS)

    Lewandowski, K.; Poferl, D. J.; Svevla, R.

    1969-01-01

    Thermodynamic and transport properties include ratio of specific heats, molecular weight, viscosity, heat capacity, thermal conductivity, and Prandtl number. Properties are calculated from 300 to 2500 degrees K and for pressures of three and ten atmospheres.

  9. Combustion properties of biomass

    Microsoft Academic Search

    B. M Jenkins; L. L Baxter; T. R Miles

    1998-01-01

    Properties of biomass relevant to combustion are briefly reviewed. The compositions of biomass among fuel types are variable, especially with respect to inorganic constituents important to the critical problems of fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, and facilitated by the presence of chlorine, are responsible for many

  10. Combustion engineering issues for solid fuel systems

    SciTech Connect

    Bruce Miller; David Tillman [Pennsylvania State University, University Park, PA (United States). Energy Institute

    2008-05-15

    The book combines modeling, policy/regulation and fuel properties with cutting edge breakthroughs in solid fuel combustion for electricity generation and industrial applications. This book provides real-life experiences and tips for addressing the various technical, operational and regulatory issues that are associated with the use of fuels. Contents are: Introduction; Coal Characteristics; Characteristics of Alternative Fuels; Characteristics and Behavior of Inorganic Constituents; Fuel Blending for Combustion Management; Fuel Preparation; Conventional Firing Systems; Fluidized-Bed Firing Systems; Post-Combustion Emissions Control; Some Computer Applications for Combustion Engineering with Solid Fuels; Gasification; Policy Considerations for Combustion Engineering.

  11. Ideal combustion of solid fuels

    SciTech Connect

    Ling, S.C.; Pao, H.P.

    1988-01-01

    Unlike the unstable, runaway, combustion of micro-fuel particles, solid fuel in the reconstituted form of a specifically shaped charge was found to have stable and ideal combustion characteristics suitable for the automatic control of combustion rate and temperature. Consequently, most environmental and operational problems associated with the atomized-combustion process can be eliminated. The shaped-charge fuel is applicable for both large power generation as well as for small home heating. 1 ref., 3 figs.

  12. Solution combustion synthesis using Schiff-base aluminum complex without fuel and optical property investigations of alumina nanoparticles

    NASA Astrophysics Data System (ADS)

    Salehi, Mehdi; Arabsarhangi, Ehsan

    2015-05-01

    Synthesis of alumina nanomaterials via a solution combustion technique using Schiff base aluminum (III) complex at 820 and 950 °C for 4 h was performed successfully. The synthesis procedure was performed using the complex in the absence and presence of urea and glycine as fuel for comparison. The obtained data showed that the procedure without using fuel resulted in a better phase and morphology. To investigate the phase formation, powder X-ray diffraction technique was used. Also, SEM micrographs were used to investigate the morphology of the obtained materials. The optical properties of the obtained materials were studied by FTIR spectra. According to the PXRD data, it was found that with annealing at 950 °C, the phase formation of the obtained materials showed cubic crystal structure with cell parameter a = 3.14 Ĺ for gamma phase. Also, by annealing at 820 °C using fuels for 4 h, the main phase was found to be in gamma.

  13. Fuel and Combustion Calculations

    Microsoft Academic Search

    Prabir Basu; Cen Kefa; Louis Jestin

    \\u000a Fuel is the single most important contributor to the cost of steam generation. It also governs the design, operation, and\\u000a performance of the boiler. Even the most fuel-flexible boilers, e.g., fluidized bed boilers, are fuel dependent, albeit to\\u000a a lesser degree. For this reason any design or even design planning, must start from a consideration of the fuel to be

  14. INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING

    E-print Network

    INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE Prepared For: California Energy REPORT (FAR) INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE CYCLES EISG AWARDEE University://www.energy.ca.gov/research/index.html. #12;Page 1 Integral Catalytic Combustion/Fuel Reforming for Gas Turbine Cycles EISG Grant # 99

  15. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, Bertrand D. (Erie, PA); Confer, Gregory L. (Erie, PA); Shen, Zujing (Erie, PA); Hapeman, Martin J. (Edinboro, PA); Flynn, Paul L. (Fairview, PA)

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slutty, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure.

  16. Fuel system for internal combustion engines

    Microsoft Academic Search

    1984-01-01

    A fuel system for an internal combustion engine of the piston type vaporizes liquid fuel such as gasoline and delivers the same through inter-communicating control valves, one of which is responsive in operation to inlet manifold pressure in the internal combustion engine and the other responsive in operation to accelerator linkage controlling the internal combustion engine's operation. The system's principal

  17. Catalytic combustion of residual fuels

    NASA Astrophysics Data System (ADS)

    Bulzan, D. L.; Tacina, R. R.

    A noble metal catalytic reactor was tested using two grades of petroleum derived residual fuels at specified inlet air temperatures, pressures, and reference velocities. Combustion efficiencies greater than 99.5 percent were obtained. Steady state operation of the catalytic reactor required inlet air temperatures of at least 800 K. At lower inlet air temperatures, upstream burning in the premixing zone occurred which was probably caused by fuel deposition and accumulation on the premixing zone walls. Increasing the inlet air temperature prevented this occurrence. Both residual fuels contained about 0.5 percent nitrogen by weight. NO sub x emissions ranged from 50 to 110 ppm by volume at 15 percent excess O2. Conversion of fuel-bound nitrogen to NO sub x ranged from 25 to 50 percent.

  18. Algae, Canola, or Palm Oils—Diesel Microemulsion Fuels: Phase Behaviors, Viscosity, and Combustion Properties

    Microsoft Academic Search

    Linh D. Do; Vinay Singh; Lixia Chen; Tohren C. G. Kibbey; Sub. R. Gollahalli; David A. Sabatini

    2011-01-01

    Vegetable oils are being considered as a renewable energy alternative for diesel. The high viscosity of vegetable oils causes injector fouling and durability problems in compression–ignition engines. Microemulsification can be used to reduce vegetable oil viscosity without complex chemical transformation processes. The goal of our work is to formulate reverse micellar microemulsions of vegetable oils and No. 2 diesel fuel

  19. Gas turbine alternative fuels combustion characteristics

    Microsoft Academic Search

    R. James Rollbuhler

    1989-01-01

    An experimental investigation was conducted to obtain combustion performance and exhaust pollutant concentrations for specific synthetic hydrocarbon fuels. Baseline comparison fuels used were gasoline and diesel fuel number two. Testing was done over a range of fuel to air mass ratios, total mass flow rates, and input combustion air temperatures in a flame-tube-type gas turbine combustor. Test results were obtained

  20. Combustor nozzle for a fuel-flexible combustion system

    DOEpatents

    Haynes, Joel Meier (Niskayuna, NY); Mosbacher, David Matthew (Cohoes, NY); Janssen, Jonathan Sebastian (Troy, NY); Iyer, Venkatraman Ananthakrishnan (Mason, OH)

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  1. Computer program for obtaining thermodynamic and transport properties of air and products of combustion of ASTM-A-1 fuel and air

    NASA Technical Reports Server (NTRS)

    Hippensteele, S. A.; Colladay, R. S.

    1978-01-01

    A computer program for determining desired thermodynamic and transport property values by means of a three-dimensional (pressure, fuel-air ratio, and either enthalpy or temperature) interpolation routine was developed. The program calculates temperature (or enthalpy), molecular weight, viscosity, specific heat at constant pressure, thermal conductivity, isentropic exponent (equal to the specific heat ratio at conditions where gases do not react), Prandtl number, and entropy for air and a combustion gas mixture of ASTM-A-1 fuel and air over fuel-air ratios from zero to stoichiometric, pressures from 1 to 40 atm, and temperatures from 250 to 2800 K.

  2. Risk factors of jet fuel combustion products.

    PubMed

    Tesseraux, Irene

    2004-04-01

    Air travel is increasing and airports are being newly built or enlarged. Concern is rising about the exposure to toxic combustion products in the population living in the vicinity of large airports. Jet fuels are well characterized regarding their physical and chemical properties. Health effects of fuel vapors and liquid fuel are described after occupational exposure and in animal studies. Rather less is known about combustion products of jet fuels and exposure to those. Aircraft emissions vary with the engine type, the engine load and the fuel. Among jet aircrafts there are differences between civil and military jet engines and their fuels. Combustion of jet fuel results in CO2, H2O, CO, C, NOx, particles and a great number of organic compounds. Among the emitted hydrocarbons (HCs), no compound (indicator) characteristic for jet engines could be detected so far. Jet engines do not seem to be a source of halogenated compounds or heavy metals. They contain, however, various toxicologically relevant compounds including carcinogenic substances. A comparison between organic compounds in the emissions of jet engines and diesel vehicle engines revealed no major differences in the composition. Risk factors of jet engine fuel exhaust can only be named in context of exposure data. Using available monitoring data, the possibilities and limitations for a risk assessment approach for the population living around large airports are presented. The analysis of such data shows that there is an impact on the air quality of the adjacent communities, but this impact does not result in levels higher than those in a typical urban environment. PMID:15093276

  3. Mechanism of combustion of disperse fuel systems

    Microsoft Academic Search

    V. M. Ivanov; I. V. Radovitskii; V. A. Tsenev

    1986-01-01

    This paper discusses the phenomenon known as ''microexplosion''-the breakup of drops in the combustion of emulsified fuels. This can also be termed intrachamber fragmentation, which is characteristic for all fuel emulsions containing a polar liquid (water, methanol, ethanol, etc), including emulsified gasolines and also threecomponent disperse fuel systems consisting of boiler fuel, coal, and water, i e., coal-boiler fuel slurries.

  4. Dependence of premixed low-temperature diesel combustion on fuel ignitability and volatility

    Microsoft Academic Search

    T Li; R Moriwaki; H Ogawa; R Kakizaki; M Murase

    2012-01-01

    A comprehensive study of fuel property effects in internal combustion engines is required to enable fuel diversification as well as the development of applications to advanced engines for operation with a variety of combustion modes. The objective of this paper is to investigate the effects of fuel ignitability and volatility over a wide range of premixed low-temperature combustion (LTC) modes

  5. Oscillating combustion from a premix fuel nozzle

    SciTech Connect

    Richards, G.A.; Yip, M.J.

    1995-08-01

    Stringent emissions requirements for stationary gas turbines have produced new challenges in combustor design. In the past, very low NOx pollutant emissions have been achieved through various combustion modifications, such as steam or water injection, or post-combustion cleanup methods such as selective catalytic reduction (SCR). An emerging approach to NOx abatement is lean premix combustion. Lean premix combustion avoids the cost and operational problems associated with other NOx control methods. By premixing fuel and air at very low equivalence ratios, the high temperatures which produce NOx are avoided. The challenges of premix combustion include avoiding flashback, and ensuring adequate fuel/air premixing. In addition, the combustion must be stable. The combustor should not operate so close to extinction that a momentary upset will extinguish the flame (static stability), and the flame should not oscillate (dynamic stability). Oscillations are undesirable because the associated pressure fluctuations can shorten component lifetime. Unfortunately, experience has shown that premix fuel nozzles burning natural gas are susceptible to oscillations. Eliminating these oscillations can be a costly and time consuming part of new engine development. As part of the U.S. Department of Energy`s Advanced Turbine Systems Program, the Morgantown Energy Technology Center (METC) is investigating the issue of combustion oscillations produced by lean premix fuel nozzles. METC is evaluating various techniques to stabilize oscillating combustion in gas turbines. Tests results from a premix fuel nozzle using swirl stabilization and a pilot flame are reported here.

  6. Fuel character effects on the TF41 engine combustion system

    Microsoft Academic Search

    R. E. Vogel; D. L. Troth

    1983-01-01

    The effects of fuel property variations on the performance and exhaust emissions of the Allison TF41 engine combustion system were determined by combustor rig tests and data analysis. Hot section durability characteristics were evaluated through computer simulations. Twelve refined and blended fuels which incorporated variations in hydrogen content, aromatic type and content, distillation range, and viscosity were evaluated. At high-power

  7. Fuel control apparatus in internal combustion engine

    SciTech Connect

    Morita, K.; Miyake, J.; Hatanaka, K.; Sakuma, K.

    1988-05-17

    A fuel control apparatus is an internal combustion engine arranged to increase a quantity of fuel supply uniquely determined on the basis of an engine speed and a quantity of suction air by a predetermined quantity upon detection of acceleration of the internal combustion engine is described comprising: a detection means for detecting acceleration and deceleration of the internal combustion engine; an engine speed operation means for calculating the number of engine resolutions; a calculation means for calculating a continuous acceleration correcting factor representing a quantity to be subtracted from the predetermined quantity in accordance with the value of integration of the number of engine revolutions calculated by the engine speed operation means; and a fuel supply means for supplying fuel to the internal combustion engine in accordance with an output of the calculation means.

  8. Engine combustion control via fuel reactivity stratification

    DOEpatents

    Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

    2013-12-31

    A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

  9. Combustion Science for Cleaner Fuels

    SciTech Connect

    Ahmed, Musahid

    2014-10-17

    Musahid Ahmed discusses how he and his team use the Advanced Light Source (ALS) to study combustion chemistry at our '8 Big Ideas' Science at the Theater event on October 8th, 2014, in Oakland, California.

  10. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Fueling internal combustion engines. 57.4103 Section 57.4103...housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  11. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section...Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines, except diesels, shall be...

  12. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Fueling internal combustion engines. 57.4103 Section 57.4103...housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  13. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 false Fueling internal combustion engines. 56.4103 Section 56.4103...housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  14. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Fueling internal combustion engines. 57.4103 Section 57.4103...housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  15. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false Fueling internal combustion engines. 56.4103 Section 56.4103...housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  16. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false Fueling internal combustion engines. 56.4103 Section 56.4103...housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  17. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Fueling internal combustion engines. 57.4103 Section 57.4103...housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  18. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false Fueling internal combustion engines. 56.4103 Section 56.4103...housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  19. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Internal combustion engines; fueling. 77.1105 Section... Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines, except diesels, shall be shut...

  20. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Internal combustion engines; fueling. 77.1105 Section... Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines, except diesels, shall be shut...

  1. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Fueling internal combustion engines. 57.4103 Section 57.4103 ...housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before...

  2. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Internal combustion engines; fueling. 77.1105 Section... Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines, except diesels, shall be shut...

  3. Fuel Interchangeability Considerations for Gas Turbine Combustion

    SciTech Connect

    Ferguson, D.H.

    2007-10-01

    In recent years domestic natural gas has experienced a considerable growth in demand particularly in the power generation industry. However, the desire for energy security, lower fuel costs and a reduction in carbon emissions has produced an increase in demand for alternative fuel sources. Current strategies for reducing the environmental impact of natural gas combustion in gas turbine engines used for power generation experience such hurdles as flashback, lean blow-off and combustion dynamics. These issues will continue as turbines are presented with coal syngas, gasified coal, biomass, LNG and high hydrogen content fuels. As it may be impractical to physically test a given turbine on all of the possible fuel blends it may experience over its life cycle, the need to predict fuel interchangeability becomes imperative. This study considers a number of historical parameters typically used to determine fuel interchangeability. Also addressed is the need for improved reaction mechanisms capable of accurately modeling the combustion of natural gas alternatives.

  4. The hydrogen-fueled internal combustion engine: a technical review

    Microsoft Academic Search

    C. M. White; R. R. Steeper; A. E. Lutz

    2006-01-01

    A review is given of contemporary research on the hydrogen-fueled internal combustion engine. The emphasis is on light- to medium-duty engine research. We first describe hydrogen-engine fundamentals by examining the engine-specific properties of hydrogen and surveying the existing literature. Here it will be shown that, due to low volumetric efficiencies and frequent preignition combustion events, the power densities of premixed

  5. Experimental study of gas turbine combustion with elevated fuel temperatures

    NASA Astrophysics Data System (ADS)

    Wiest, Heather K.

    Many thermal management challenges have developed as advancements in gas turbine engine designs are made. As the thermal demands on gas turbine engines continue to increase, the heat sink available in the combustor fuel flow becomes more attractive. Increasing the temperature of fuel by using it as a heat sink can lead to higher combustion efficiency due to the increase in flow enthalpy and improved vaporization of the heated fuel. Emissions levels can also be affected by using heated fuels with the levels of carbon monoxide and unburned hydrocarbons tending to decrease while the amount of the oxides of nitrogen tends to increase. Although there are several benefits associated with using heated fuels in gas turbine engines, some problems can arise from their use including combustion instabilities, flashing within the fuel injector, and fuel coking or deposit formation within the fuel system. Various deoxygenation methods have been created to address the coking problem seen when using heated fuels. In the Gas Turbine Test Cell of the High Pressure Laboratory at Purdue University's Maurice J. Zucrow Laboratories, a 5 MW combustion rig was developed to complete combustion test with heated fuels. The facility's supply systems including heated air, jet fuel, cooling water, and nitrogen were designed and integrated to produce simulated engine conditions within the combustion rig. Heating capabilities produced fuel temperatures ranging up to 600 deg F. Testing was completed with two fuel deoxygenation methods: nitrogen sparging and catalytic deoxygenation. Results from the testing campaign included conventional pressure, temperature, and fuel property measurements; however, the most important measurements were the emissions samples that were analyzed for each test condition. Levels of carbon monoxide, unburned hydrocarbons, and oxides of nitrogen were determined as well as the combustion efficiency calculated from these emissions measurements. The trends in emissions and performance from the increase in fuel temperature will be discussed. In addition, high frequency pressure data were recorded during testing to monitor combustion instabilities. Fuel samples were also taken and analyzed to document the changes in the volatile composition of the fuel from the two deoxygenation methods. The testing campaign was extremely successful. All project objectives were met with the heated fuel testing campaign. The combustion rig was run safely with fuel temperature up to 600 deg F, allowing the effects of elevated fuel temperatures on the performance and emissions of a gas turbine combustor to be evaluated as planned.

  6. Characteristics and combustion of future hydrocarbon fuels. [aircraft fuels

    NASA Technical Reports Server (NTRS)

    Rudey, R. A.; Grobman, J. S.

    1978-01-01

    As the world supply of petroleum crude oil is being depleted, the supply of high-quality crude oil is also dwindling. This dwindling supply is beginning to manifest itself in the form of crude oils containing higher percentages of aromatic compounds, sulphur, nitrogen, and trace constituents. The result of this trend is described and the change in important crude oil characteristics, as related to aircraft fuels, is discussed. As available petroleum is further depleted, the use of synthetic crude oils (those derived from coal and oil shale) may be required. The principal properties of these syncrudes and the fuels that can be derived from them are described. In addition to the changes in the supply of crude oil, increasing competition for middle-distillate fuels may require that specifications be broadened in future fuels. The impact that the resultant potential changes in fuel properties may have on combustion and thermal stability characteristics is illustrated and discussed in terms of ignition, soot formation, carbon deposition flame radiation, and emissions.

  7. Dual fuel system for internal combustion engine

    SciTech Connect

    Haman, D.F.; Needham, D.M.

    1989-06-06

    An internal combustion engine is described comprising a crankcase, a cylinder extending from the crankcase and defining a combustion chamber having an inlet port, a transfer passage communicating between the crankcase and the inlet port, a carburetor having an air induction passage communicating with the crankcase and including a venturi and a float bowl adapted to contain fuel for normal operation, a throttle valve intermediate the venturi and the crankcase.

  8. Combustion characteristics of gas turbine alternative fuels

    Microsoft Academic Search

    Rollbuhler

    1987-01-01

    An experimental investigation, cosponsored by the Department of Energy and NASA, was conducted to obtain combustion performance values for specific heavy-end, synthetic hydrocarbon fuels. A flame tube combustor modified to duplicate an advanced gas turbine engine combustor was used for the tests. Each fuel was tested at steady-state operating conditions over a range of mass flow rates, fuel-to-air mass ratio,

  9. Hybrid combustion with metallized fuels

    NASA Technical Reports Server (NTRS)

    Yi, Jianwen; Wygle, Brian S.; Bates, Ronald W.; Jones, Michael D.; Ramohalli, Kumar

    1993-01-01

    A chemical method of adding certain catalysts to improve the degradation process of a solid fuel is discussed. Thermogravimetric (TGA) analysis used to study the fundamental degradation behavior of a typical hybrid fuel (HTPB) shows that high surface temperatures increase the degradation rate. Fuels were tested in a laboratory-scale experimental hybrid rocket and their behavior was compared to a baseline behavior of HTPB fuel regression rates. It was found that a small amount of metal powder added to the fuel can significantly increase the regression rates.

  10. Fuel reforming for scramjet thermal management and combustion optimization

    E-print Network

    Paris-Sud XI, Université de

    Fuel reforming for scramjet thermal management and combustion optimization E. DANIAU* , M. BOUCHEZ in a Scramjet combustion chamber. Another critical point is that mixing and combustion should be sufficiently

  11. Combustion engine for solid and liquid fuels

    NASA Technical Reports Server (NTRS)

    Pabst, W.

    1986-01-01

    A combustion engine having no piston, a single cylinder, and a dual-action, that is applicable for solid and liquid fuels and propellants, and that functions according to the principle of annealing point ignition is presented. The invention uses environmentally benign amounts of fuel and propellants to produce gas and steam pressure, and to use a simple assembly with the lowest possible consumption and constant readiness for mixing and burning. The advantage over conventional combustion engines lies in lower consumption of high quality igniting fluid in the most cost effective manner.

  12. Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 28152820 FINGERING INSTABILITY IN SOLID FUEL COMBUSTION

    E-print Network

    Moses, Elisha

    2815 Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 2815­2820 FINGERING INSTABILITY IN SOLID FUEL COMBUSTION: THE CHARACTERISTIC SCALES OF THE DEVELOPED STATE ORY ZIK, Israel We present new results on the fingering instability in solid fuel combustion. The instability

  13. Fuel control system for internal combustion engine

    SciTech Connect

    Koshizawa, T.; Yoshimura, H.; Sugimura, T.

    1988-09-27

    This patent describes a fuel control system for an internal combustion engine having fuel supply means for metering fuel to be supplied to the engine in response to an electric command given by fuel supply command means. The fuel control system consists of: a step motor for driving a fuel metering member of the fuel supply means; learning means for learning the number of steps required for energizing the step motor to move the fuel metering member from an idle position to a full-load position; computing means for computing the number of steps required for the step motor to reach a target load position by dividing in proportion the learned number of steps by a ratio between a target load value of an electric command from the fuel supply command means and a maximum value of the electric command; and drive means for energizing the step motor to achieve the number of steps computed by the computing means.

  14. Fuel supplying device for internal combustion engine

    SciTech Connect

    Ishida, T.; Miki, T.; Nakamura, H.; Takamiya, B.

    1982-07-13

    A fuel supplying device for an internal combustion engine is disclosed which has a fuel supply passage for introducing fuel fed from a fuel pump at a substantially constant pressure to a fuel injector operative at a predetermined constant pressure. The fuel injector is installed at a congregated portion of engine intake manifolds. A metering valve includes a motor so that the pressure drop is maintained substantially constant by a differential regulator. The metering valve is disposed in an intermediate portion of the fuel supply passage. Calculating means including a servo signal generator calculates an injection flow amount causing a predetermined air/fuel ratio on the basis of signals of various engine running factors. An operational signal output from the servo signal generating circuit of the calculating means is applied to the drive motor means for driving said metering valve to thereby inject fuel into the intake manifolds.

  15. Particle emissions from laboratory combustion of wildland fuels: In situ optical and mass measurements

    Microsoft Academic Search

    L.-W. Antony Chen; Hans Moosmüller; W. Patrick Arnott; Judith C. Chow; John G. Watson; Ronald A. Susott; Ronald E. Babbitt; Cyle E. Wold; Emily N. Lincoln; Wei Min Hao

    2006-01-01

    Time-resolved optical properties of smoke particles from the controlled laboratory combustion of mid-latitude wildland fuels were determined for the first time using advanced techniques, including cavity ring-down\\/cavity enhanced detection (CRD\\/CED) for light extinction and two-wavelength photoacoustic detection for light absorption. This experiment clearly resolves the dependence of smoke properties on fuel and combustion phase. Intensive flaming combustion during ponderosa pine

  16. CONTROLLING EMISSIONS FROM FUEL AND WASTE COMBUSTION

    EPA Science Inventory

    Control of emissions from combustion of fuels and wastes has been a traditional focus of air pollution regulations. Significant technology developments of the '50s and '60s have been refined into reliable chemical and physical process unit operations. In the U.S., acid rain legis...

  17. A comprehensive combustion model for biodiesel-fueled engine simulations

    NASA Astrophysics Data System (ADS)

    Brakora, Jessica L.

    Engine models for alternative fuels are available, but few are comprehensive, well-validated models that include accurate physical property data as well as a detailed description of the fuel chemistry. In this work, a comprehensive biodiesel combustion model was created for use in multi-dimensional engine simulations, specifically the KIVA3v R2 code. The model incorporates realistic physical properties in a vaporization model developed for multi-component fuel sprays and applies an improved mechanism for biodiesel combustion chemistry. A reduced mechanism was generated from the methyl decanoate (MD) and methyl-9-decenoate (MD9D) mechanism developed at Lawrence Livermore National Laboratory. It was combined with a multi-component mechanism to include n-heptane in the fuel chemistry. The biodiesel chemistry was represented using a combination of MD, MD9D and n-heptane, which varied for a given fuel source. The reduced mechanism, which contained 63 species, accurately predicted ignition delay times of the detailed mechanism over a range of engine-specific operating conditions. Physical property data for the five methyl ester components of biodiesel were added to the KIVA library. Spray simulations were performed to ensure that the models adequately reproduce liquid penetration observed in biodiesel spray experiments. Fuel composition impacted liquid length as expected, with saturated species vaporizing more and penetrating less. Distillation curves were created to ensure the fuel vaporization process was comparable to available data. Engine validation was performed against a low-speed, high-load, conventional combustion experiments and the model was able to predict the performance and NOx formation seen in the experiment. High-speed, low-load, low-temperature combustion conditions were also modeled, and the emissions (HC, CO, NOx) and fuel consumption were well-predicted for a sweep of injection timings. Finally, comparisons were made between the results of biodiesel composition (palm vs. soy) and fuel blends (neat vs. B20). The model effectively reproduced the trends observed in the experiments.

  18. Catalytic combustion with incompletely vaporized residual fuel

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1981-01-01

    Catalytic combustion of fuel lean mixtures of incompletely vaporized residual fuel and air was investigated. The 7.6 cm diameter, graded cell reactor was constructed from zirconia spinel substrate and catalyzed with a noble metal catalyst. Streams of luminous particles exited the rector as a result of fuel deposition and carbonization on the substrate. Similar results were obtained with blends of No. 6 and No. 2 oil. Blends of shale residual oil and No. 2 oil resulted in stable operation. In shale oil blends the combustor performance degraded with a reduced degree of fuel vaporization. In tests performed with No. 2 oil a similar effect was observed.

  19. Effect of different fuels on structural, photo and thermo luminescence properties of solution combustion prepared Y2SiO5 nanopowders

    NASA Astrophysics Data System (ADS)

    Ramakrishna, G.; Nagabhushana, H.; Sunitha, D. V.; Prashantha, S. C.; Sharma, S. C.; Nagabhushana, B. M.

    2014-06-01

    Y2SiO5 nanopowders are prepared by solution combustion method using DFH, sugar and urea as fuels. The final product was well characterized by powder X-ray diffraction, Scanning Electron Microscopy and UV-Vis spectroscopy. The average crystallite size was estimated using Debye-Scherer's formula and Williamson-Hall plots and are found to be in the range 34-40 nm for DFH, 45-50 nm for urea and 35-42 nm for sugar respectively. X1-X2 type YSO phase was obtained for all the samples calcined from 1200 to 1400 °C. The optical energy band gaps (Eg) of the samples were estimated from Tauc relation and varies from 5.58 to 5.60 eV. SEM micrographs of sugar and urea used Y2SiO5 show agglomerated particles with porous morphology. However, for the sample prepared using DFH fuel observed to be almost spherical in shape. Thermoluminescence (TL) properties of ?-irradiated (1-5 kGy) and UV irradiated (1-30 min) Y2SiO5 nanopowder at a heating rate of 2.5 °C s-1 was studied. The samples prepared by using urea and sugar fuels show a broad TL glow peak at 189 °C. However, DFH used Y2SiO5 show a well resolved peak at 196 °C with shouldered peak at 189 °C. Among the fuels, DFH used Y2SiO5 show simple glow peak structure which perhaps useful in radiation dosimetry. This may be due to fuel and particle size effect. The kinetic parameters such as activation energy (E), frequency factor (s) and order of kinetics are estimated by Chens glow peak shape method.

  20. Effect of different fuels on structural, photo and thermo luminescence properties of solution combustion prepared Y(2)SiO(5) nanopowders.

    PubMed

    Ramakrishna, G; Nagabhushana, H; Sunitha, D V; Prashantha, S C; Sharma, S C; Nagabhushana, B M

    2014-06-01

    Y(2)SiO(5) nanopowders are prepared by solution combustion method using DFH, sugar and urea as fuels. The final product was well characterized by powder X-ray diffraction, Scanning Electron Microscopy and UV-Vis spectroscopy. The average crystallite size was estimated using Debye-Scherer's formula and Williamson-Hall plots and are found to be in the range 34-40nm for DFH, 45-50nm for urea and 35-42nm for sugar respectively. X1-X2 type YSO phase was obtained for all the samples calcined from 1200 to 1400°C. The optical energy band gaps (Eg) of the samples were estimated from Tauc relation and varies from 5.58 to 5.60eV. SEM micrographs of sugar and urea used Y(2)SiO(5) show agglomerated particles with porous morphology. However, for the sample prepared using DFH fuel observed to be almost spherical in shape. Thermoluminescence (TL) properties of ?-irradiated (1-5kGy) and UV irradiated (1-30min) Y(2)SiO(5) nanopowder at a heating rate of 2.5°Cs(-1) was studied. The samples prepared by using urea and sugar fuels show a broad TL glow peak at 189°C. However, DFH used Y(2)SiO(5) show a well resolved peak at 196°C with shouldered peak at 189°C. Among the fuels, DFH used Y(2)SiO(5) show simple glow peak structure which perhaps useful in radiation dosimetry. This may be due to fuel and particle size effect. The kinetic parameters such as activation energy (E), frequency factor (s) and order of kinetics are estimated by Chens glow peak shape method. PMID:24632171

  1. Biomass fuel combustion and health*

    PubMed Central

    de Koning, H. W.; Smith, K. R.; Last, J. M.

    1985-01-01

    Biomass fuels (wood, agricultural waste, and dung) are used by about half the world's population as a major, often the only, source of domestic energy for cooking and heating. The smoke emissions from these fuels are an important source of indoor air pollution, especially in rural communities in developing countries. These emissions contain important pollutants that adversely affect health—such as suspended particulate matter and polycyclic organic matter which includes a number of known carcinogens, such as benzo[a]pyrene, as well as gaseous pollutants like carbon monoxide and formaldehyde. Exposure to large amounts of smoke may present a health risk that is of a similar order of magnitude to the risk from tobacco smoke. The effects on health arising from exposure to air pollution are reviewed, based on what has been reported in the literature so far. Further and more detailed information on exposures and on the epidemiological aspects is urgently required. The persons most frequently affected are women who do the cooking for households in rural villages; they suffer from impaired health due to prolonged and repeated contact with these harmful pollutants. When they are pregnant, the developing fetus may also be exposed and this leads to the risk of excess deaths. In the developing countries, exposure to biomass fuel emissions is probably one of the most important occupational health hazards for women. A conservatively estimated 300-400 million people worldwide, mostly in the rural areas of developing countries, are affected by these problems. PMID:3872729

  2. Plasma-aided solid fuel combustion

    SciTech Connect

    E.I. Karpenko; V.E. Messerle; A.B. Ustimenko ['United Power System of Russia', Gusinoozersk (Russian Federation). Branch Centre of Plasma-Power Technologies of Russian J.S.Co.

    2007-07-01

    Plasma supported solid fuel combustion is promising technology for use in thermal power plants (TPP). The realisation of this technology comprises two main steps. The first is the execution of a numerical simulation and the second involves full-scale trials of plasma supported coal combustion through plasma-fuel systems (PFS) mounted on a TPP boiler. For both the numerical simulation and the full-scale trials, the boiler of 200 MW power of Gusinoozersk TPP (Russia) was selected. The optimization of the combustion of low-rank coals using plasma technology is described, together with the potential of this technology for the general optimization of the coal burning process. Numerical simulation and full-scale trials have enabled technological recommendations for improvement of existing conventional TPP to be made. PFS have been tested for boilers plasma start-up and flame stabilization in different countries at 27 power boilers steam productivity of 75-670 tons per hour (TPH) equipped with different type of pulverised coal burners. At PFS testing power coals of all ranks (brown, bituminous, anthracite and their mixtures) were used. Volatile content of them varied from 4 to 50%, ash from 15 to 48% and calorific values from 6700 to 25,100 KJ/kg. In summary, it is concluded that the developed and industrially tested PFS improve coal combustion efficiency and decrease harmful emission from pulverised coal-fired TPP. 9 refs., 14 figs., 2 tabs.

  3. Toward the Impact of Fuel Evaporation-Combustion Interaction on Spray Combustion in Gas Turbine Combustion Chambers. Part I: Effect of Partial Fuel Vaporization on Spray Combustion

    Microsoft Academic Search

    Amsini Sadiki; W. Ahmadi; Mouldi Chrigui; J. Janicka

    \\u000a This work aims at investigating the impact of the interaction between evaporation process and combustion on spray combustion\\u000a characteristics in gas turbine combustion chambers. It is subdivided into two parts. The first part studies how the evaporation\\u000a process affects the behavior of partially pre-vaporized spray combustion. The second part attempts to answer the question\\u000a how the fuel evaporation process behaves

  4. THEORETICAL INVESTIGATION OF THE PERFORMANCE OF ALTERNATIVE AVIATION FUELS IN AN AERO-ENGINE COMBUSTION CHAMBER

    Microsoft Academic Search

    I. Uryga; M. Pourkashanian; D. Borman; E. Catalanotti; C. W. Wilson

    2009-01-01

    When considering alternative fuels for aviation, factors such as the overall efficiency of the combustion process and the levels of emissions emitted to the atmosphere, need to be critically evaluated. The physical and chemical properties of a fuel influence the combustion efficiency and emissions and therefore need to be considered. The energy content of a biofuel, which is influenced negatively

  5. Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines

    SciTech Connect

    Venkatesan, Krishna

    2011-11-30

    The purpose of this program was to develop low-emissions, efficient fuel-flexible combustion technology which enables operation of a given gas turbine on a wider range of opportunity fuels that lie outside of current natural gas-centered fuel specifications. The program encompasses a selection of important, representative fuels of opportunity for gas turbines with widely varying fundamental properties of combustion. The research program covers conceptual and detailed combustor design, fabrication, and testing of retrofitable and/or novel fuel-flexible gas turbine combustor hardware, specifically advanced fuel nozzle technology, at full-scale gas turbine combustor conditions. This project was performed over the period of October 2008 through September 2011 under Cooperative Agreement DE-FC26-08NT05868 for the U.S. Department of Energy/National Energy Technology Laboratory (USDOE/NETL) entitled "Fuel Flexible Combustion Systems for High-Efficiency Utilization of Opportunity Fuels in Gas Turbines". The overall objective of this program was met with great success. GE was able to successfully demonstrate the operability of two fuel-flexible combustion nozzles over a wide range of opportunity fuels at heavy-duty gas turbine conditions while meeting emissions goals. The GE MS6000B ("6B") gas turbine engine was chosen as the target platform for new fuel-flexible premixer development. Comprehensive conceptual design and analysis of new fuel-flexible premixing nozzles were undertaken. Gas turbine cycle models and detailed flow network models of the combustor provide the premixer conditions (temperature, pressure, pressure drops, velocities, and air flow splits) and illustrate the impact of widely varying fuel flow rates on the combustor. Detailed chemical kinetic mechanisms were employed to compare some fundamental combustion characteristics of the target fuels, including flame speeds and lean blow-out behavior. Perfectly premixed combustion experiments were conducted to provide experimental combustion data of our target fuels at gas turbine conditions. Based on an initial assessment of premixer design requirements and challenges, the most promising sub-scale premixer concepts were evaluated both experimentally and computationally. After comprehensive screening tests, two best performing concepts were scaled up for further development. High pressure single nozzle tests were performed with the scaled premixer concepts at target gas turbine conditions with opportunity fuels. Single-digit NOx emissions were demonstrated for syngas fuels. Plasma-assisted pilot technology was demonstrated to enhance ignition capability and provide additional flame stability margin to a standard premixing fuel nozzle. However, the impact of plasma on NOx emissions was observed to be unacceptable given the goals of this program and difficult to avoid.

  6. Numerical modeling of hydrogen-fueled internal combustion engines

    SciTech Connect

    Johnson, N.L.; Amsden, A.A.

    1996-12-31

    The planned use of hydrogen as the energy carrier of the future introduces new challenges and opportunities, especially to the engine design community. Hydrogen is a bio-friendly fuel that can be produced from renewable resources and has no carbon dioxide combustion products; and in a properly designed ICE, almost zero NO{sub x} and hydrocarbon emissions can be achieved. Because of the unique properties of hydrogen combustion - in particular the highly wrinkled nature of the laminar flame front due to the preferential diffusion instability - modeling approaches for hydrocarbon gaseous fuels are not generally applicable to hydrogen combustion. This paper reports on the current progress to develop a engine design capability based on KIVA family of codes for hydrogen-fueled, spark-ignited engines in support of the National Hydrogen Program. A turbulent combustion model, based on a modified eddy-turnover model in conjunction with an intake flow valve model, is found to describe well the efficiency and NO{sub x} emissions of this engine satisfy the Equivalent Zero Emission Vehicle (EZEV) standard established by the California Resource Board. 26 refs., 10 figs., 1 tab.

  7. Combustion oscillation control by cyclic fuel injection

    SciTech Connect

    Richards, G.A.; Yip, M.J. [USDOE Morgantown Energy Technology Center, WV (United States); Robey, E. [EG& G Technical Services of West Virginia, Morgantown Energy Technology Center, WV (United States); Cowell, L.; Rawlins, D. [Solar Turbines, Inc., San Diedgo, CA (United States)

    1995-04-01

    A number of recent articles have demonstrated the use of active control to mitigate the effects of combustion instability in afterburner and dump combustor applications. In these applications, cyclic injection of small quantities of control fuel has been proposed to counteract the periodic heat release that contributes to undesired pressure oscillations. This same technique may also be useful to mitigate oscillations in gas turbine combustors, especially in test rig combustors characterized by acoustic modes that do not exist in the final engine configuration. To address this issue, the present paper reports on active control of a subscale, atmospheric pressure nozzle/combustor arrangement. The fuel is natural gas. Cyclic injection of 14% control fuel in a premix fuel nozzle is shown to reduce oscillating pressure amplitude by a factor of 0.30 (i.e., {approximately}10 dB) at 300 Hz. Measurement of the oscillating heat release is also reported.

  8. Demonstration of catalytic combustion with residual fuel

    NASA Astrophysics Data System (ADS)

    Dodds, W. J.; Ekstedt, E. E.

    1981-08-01

    An experimental program was conducted to demonstrate catalytic combustion of a residual fuel oil. Three catalytic reactors, including a baseline configuration and two backup configurations based on baseline test results, were operated on No. 6 fuel oil. All reactors were multielement configurations consisting of ceramic honeycomb catalyzed with palladium on stabilized alumina. Stable operation on residual oil was demonstrated with the baseline configuration at a reactor inlet temperature of about 825 K (1025 F). At low inlet temperature, operation was precluded by apparent plugging of the catalytic reactor with residual oil. Reduced plugging tendency was demonstrated in the backup reactors by increasing the size of the catalyst channels at the reactor inlet, but plugging still occurred at inlet temperature below 725 K (845 F). Operation at the original design inlet temperature of 589 K (600 F) could not be demonstrated. Combustion efficiency above 99.5% was obtained with less than 5% reactor pressure drop. Thermally formed NO sub x levels were very low (less than 0.5 g NO2/kg fuel) but nearly 100% conversion of fuel-bound nitrogen to NO sub x was observed.

  9. Combustion characteristics of alternative liquid fuels

    E-print Network

    Chong, Cheng Tung

    2011-11-08

    -mechanism ………………………………………………………….. 30 2.2 Comparison of fuel properties ………………………………………………….. 37 CHAPTER 3 3.1 Percentage of fatty acids composition of different vegetable oils …… 60 3.2 Chemical structure of common fatty acids and their methyl esters .. 60 3... (FAME) derived from vegetable oils or animal fats through the transesterification process [7]. The transesterified fuels contain physical properties comparable to those of petroleum-based diesel fuels and are suitable to be used neat or in blends...

  10. Automotive fuels and internal combustion engines: a chemical perspective.

    PubMed

    Wallington, T J; Kaiser, E W; Farrell, J T

    2006-04-01

    Commercial transportation fuels are complex mixtures containing hundreds or thousands of chemical components, whose composition has evolved considerably during the past 100 years. In conjunction with concurrent engine advancements, automotive fuel composition has been fine-tuned to balance efficiency and power demands while minimizing emissions. Pollutant emissions from internal combustion engines (ICE), which arise from non-ideal combustion, have been dramatically reduced in the past four decades. Emissions depend both on the engine operating parameters (e.g. engine temperature, speed, load, A/F ratio, and spark timing) and the fuel. These emissions result from complex processes involving interactions between the fuel and engine parameters. Vehicle emissions are comprised of volatile organic compounds (VOCs), CO, nitrogen oxides (NO(x)), and particulate matter (PM). VOCs and NO(x) form photochemical smog in urban atmospheres, and CO and PM may have adverse health impacts. Engine hardware and operating conditions, after-treatment catalysts, and fuel composition all affect the amount and composition of emissions leaving the vehicle tailpipe. While engine and after-treatment effects are generally larger than fuel effects, engine and after-treatment hardware can require specific fuel properties. Consequently, the best prospects for achieving the highest efficiency and lowest emissions lie with optimizing the entire fuel-engine-after-treatment system. This review provides a chemical perspective on the production, combustion, and environmental aspects of automotive fuels. We hope this review will be of interest to workers in the fields of chemical kinetics, fluid dynamics of reacting flows, atmospheric chemistry, automotive catalysts, fuel science, and governmental regulations. PMID:16565750

  11. Delivery of fuel in internal combustion engines

    SciTech Connect

    Brown, S.E.

    1989-08-01

    This patent describes an improvement in an engine having a cylinder, an intake port for admitting an air-fuel mixture to the cylinder, and an intake manifold coupled with the cylinder to provide a flow passage to the intake port for the air-fuel mixture. The improvement comprising: means for presenting a reservoir in the intake manifold for collecting liquid fuel that liquifies from the air-fuel mixture; a venturi having a restricted throat and low and high pressure sides on opposite sides of the throat; means for mounting the venturi in the flow passage with the low pressure side located downstream from the high pressure side; and means for providing a passage having an inlet end communicating with the reservoir to receive the liquid fuel therefrom and an outlet end opening into the low pressure side of the venturi to deliver the liquid fuel into the air-fuel mixture following through the venturi, thereby effecting atomization of at least some of the liquid fuel to achieve more complete combustion thereof in the cylinder.

  12. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    DOEpatents

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  13. Hydrogen-fueled internal combustion engines.

    SciTech Connect

    Verhelst, S.; Wallner, T.; Energy Systems; Ghent Univ.

    2009-12-01

    The threat posed by climate change and the striving for security of energy supply are issues high on the political agenda these days. Governments are putting strategic plans in motion to decrease primary energy use, take carbon out of fuels and facilitate modal shifts. Taking a prominent place in these strategic plans is hydrogen as a future energy carrier. A number of manufacturers are now leasing demonstration vehicles to consumers using hydrogen-fueled internal combustion engines (H{sub 2}ICEs) as well as fuel cell vehicles. Developing countries in particular are pushing for H{sub 2}ICEs (powering two- and three-wheelers as well as passenger cars and buses) to decrease local pollution at an affordable cost. This article offers a comprehensive overview of H{sub 2}ICEs. Topics that are discussed include fundamentals of the combustion of hydrogen, details on the different mixture formation strategies and their emissions characteristics, measures to convert existing vehicles, dedicated hydrogen engine features, a state of the art on increasing power output and efficiency while controlling emissions and modeling.

  14. Transport Properties for Combustion Modeling

    SciTech Connect

    Brown, N.J.; Bastein, L.; Price, P.N.

    2010-02-19

    This review examines current approximations and approaches that underlie the evaluation of transport properties for combustion modeling applications. Discussed in the review are: the intermolecular potential and its descriptive molecular parameters; various approaches to evaluating collision integrals; supporting data required for the evaluation of transport properties; commonly used computer programs for predicting transport properties; the quality of experimental measurements and their importance for validating or rejecting approximations to property estimation; the interpretation of corresponding states; combination rules that yield pair molecular potential parameters for unlike species from like species parameters; and mixture approximations. The insensitivity of transport properties to intermolecular forces is noted, especially the non-uniqueness of the supporting potential parameters. Viscosity experiments of pure substances and binary mixtures measured post 1970 are used to evaluate a number of approximations; the intermediate temperature range 1 < T* < 10, where T* is kT/{var_epsilon}, is emphasized since this is where rich data sets are available. When suitable potential parameters are used, errors in transport property predictions for pure substances and binary mixtures are less than 5 %, when they are calculated using the approaches of Kee et al.; Mason, Kestin, and Uribe; Paul and Warnatz; or Ern and Giovangigli. Recommendations stemming from the review include (1) revisiting the supporting data required by the various computational approaches, and updating the data sets with accurate potential parameters, dipole moments, and polarizabilities; (2) characterizing the range of parameter space over which the fit to experimental data is good, rather than the current practice of reporting only the parameter set that best fits the data; (3) looking for improved combining rules, since existing rules were found to under-predict the viscosity in most cases; (4) performing more transport property measurements for mixtures that include radical species, an important but neglected area; (5) using the TRANLIB approach for treating polar molecules and (6) performing more accurate measurements of the molecular parameters used to evaluate the molecular heat capacity, since it affects thermal conductivity, which is important in predicting flame development.

  15. Fuel Property Effects on Emissions from High Efficiency Clean Combustion in a Diesel Engine (SAE Paper Number 2006-01-0080)

    SciTech Connect

    Sluder, Scott [ORNL; Wagner, Robert M [ORNL; Lewis Sr, Samuel Arthur [ORNL; Storey, John Morse [ORNL

    2006-01-01

    High-efficiency clean combustion (HECC) modes provide simultaneous reductions in diesel particulate matter and nitrogen-oxides emissions while retaining efficiencies characteristic of normal diesel engines. Fuel parameters may have significant impacts on the ability to operate in HECC modes and on the emissions produced in HECC modes. In this study, 3 diesel-range fuels and 2 oxygenated blends are burned in both normal and HECC modes at 3 different engine conditions. The results show that fuel effects play an important role in the emissions of hydrocarbons, particulate matter, and carbon monoxide but do not significantly impact NOX emissions in HECC modes. HECC modes are achievable with 5% biodiesel blends in addition to petroleum-based and oil-sands derived fuels. Soot precursor and oxygenated compound concentrations in the exhaust were observed to generally increase with the sooting tendency of the fuel in HECC modes.

  16. Vaporization and combustion of fuel droplets at supercritical conditions

    NASA Technical Reports Server (NTRS)

    Yang, Vigor

    1991-01-01

    Vaporization and combustion liquid-fuel droplets in both sub- and super-critical environments have been examined. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates finite-rate chemical kinetics and a full treatment of liquid-vapor phase equilibrium at the droplet surface. The governing equations and the associated interface boundary conditions are solved numerically using a fully coupled, implicit scheme with the dual time-stepping integration technique. The model is capable of treating the entire droplet history, including the transition from the subcritical to the supercritical state. As a specific example, the combustion of n-pentane fuel droplets in air is studied for pressures of 5-140 atm. In addition, the dynamic responses of droplet vaporization and combustion to ambient-pressure oscillations are investigated. Results indicate that the droplet gasification and burning mechanisms depend greatly on the ambient pressure. In particular, a rapid enlargement of the vaporization and combustion responses occurs when the droplet surface reaches its critical point, mainly due to the strong variations of latent heat of vaporization and thermophysical properties at the critical state.

  17. Radiation exposures due to fossil fuel combustion

    NASA Astrophysics Data System (ADS)

    Beck, Harold L.

    The current consensus regarding the potential radiation exposures resulting from the combustion of fossil fuels is examined. Sources, releases and potential doses to humans are discussed, both for power plants and waste materials. It is concluded that the radiation exposure to most individuals from any pathway is probably insignificant, i.e. only a tiny fraction of the dose received from natural sources in soil and building materials. Any small dose that may result from power-plant emissions will most likely be from inhalation of the small insoluble ash particles from the more poorly controlled plants burning higher than average activity fuel, rather than from direct or indirect ingestion of food grown on contaminated soil. One potentially significant pathway for exposure to humans that requires further evaluation is the effect on indoor external ?-radiation levels resulting from the use of flyash in building materials. The combustion of natural gas in private dwellings is also discussed, and the radiological consequences are concluded to be generally insignificant, except under certain extraordinary circumstances.

  18. Recent advances in the combustion of water fuel emulsion

    Microsoft Academic Search

    T. Kadota; H. Yamasaki

    2002-01-01

    Recent advances in the combustion of water fuel emulsion which consists of base fuel and water doped with or without a trace content of surfactant are reviewed. The focus is on the fundamental mechanism relevant to the micro-explosion phenomena leading to the secondary atomization which is not common to the combustion of pure fuel. Described at first are the kinetic

  19. Fuel NOx production during the combustion of low caloric value fuel

    SciTech Connect

    Colaluca, M.A.; Caraway, J.P. [Texas A and M Univ., College Station, TX (United States). Mechanical Engineering Dept.

    1997-07-01

    The objective of this investigation is to identify and qualify physical mechanisms and parameters that affect the combustion of low caloric value gases (LCVG) and the formation of NOx pollutants produced form fuel bound nitrogen. Average physical properties of a low caloric value gas were determined from the products of several industrial coal gasifiers. A computer model was developed, utilizing the PHOENICS computational fluid dynamics software to model the combustion of LCVG. The model incorporates a 3-dimensional physical design and is based on typical industrial combustors. Feed stock to the gasifier can be wood, feed stock manure, cotton gin trash, coal, lignite and numerous forms of organic industrial wastes.

  20. Investigation of Bio-Diesel Fueled Engines under Low-Temperature Combustion Strategies

    SciTech Connect

    Chia-fon F. Lee; Alan C. Hansen

    2010-09-30

    In accordance with meeting DOE technical targets this research was aimed at developing and optimizing new fuel injection technologies and strategies for the combustion of clean burning renewable fuels in diesel engines. In addition a simultaneous minimum 20% improvement in fuel economy was targeted with the aid of this novel advanced combustion system. Biodiesel and other renewable fuels have unique properties that can be leveraged to reduce emissions and increase engine efficiency. This research is an investigation into the combustion characteristics of biodiesel and its impacts on the performance of a Low Temperature Combustion (LTC) engine, which is a novel engine configuration that incorporates technologies and strategies for simultaneously reducing NOx and particulate emissions while increasing engine efficiency. Generating fundamental knowledge about the properties of biodiesel and blends with petroleum-derived diesel and their impact on in-cylinder fuel atomization and combustion processes was an important initial step to being able to optimize fuel injection strategies as well as introduce new technologies. With the benefit of this knowledge experiments were performed on both optical and metal LTC engines in which combustion and emissions could be observed and measured under realistic conditions. With the aid these experiments and detailed combustion models strategies were identified and applied in order to improve fuel economy and simultaneously reduce emissions.

  1. Combustion of liquid-fuel droplets in supercritical conditions

    NASA Technical Reports Server (NTRS)

    Shuen, J. S.; Yang, Vigor; Hsaio, C. C.

    1992-01-01

    A comprehensive analysis of liquid-fuel droplet combustion in both subcritical and supercritical environments has been conducted. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates variable thermophysical properties, finite-rate chemical kinetics, and a full treatment of liquid-vapor phase equilibrium at the drop surface. The governing equations and associated interfacial boundary conditions are solved numerically using a fully coupled, implicit scheme with the dual time-stepping integration technique. The model is capable of treating the entire droplet history, including the transition from the subcritical to supercritical state. As a specific example, the combustion of n-pentane fuel droplets in air is studied for pressures in the range of 5-140 atm. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influence on fluid transport, gas-liquid interfacial thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibit a considerable change in the combustion mechanism at the critical pressure, mainly as a result of reduced mass diffusivity and latent heat of vaporization with increased pressure.

  2. Solid fuel combustion technology for the Stirling engine

    Microsoft Academic Search

    1977-01-01

    The current status of fluidized bed combustion has been reviewed with emphasis on its potential application to industrial power or heating plants and to alternative fuels. This technology is ready for commercialization and there is strong evidence of its high adaptability to a large variety of fuels, including biomass and industrial wastes. Coal-oil slurry combustion also is being developed and

  3. Broad Specification Fuels Combustion Technology Program, Phase 2

    NASA Technical Reports Server (NTRS)

    Lohmann, R. P.; Jeroszko, R. A.; Kennedy, J. B.

    1990-01-01

    An experimental evaluation of two advanced technology combustor concepts was conducted to evolve and assess their capability for operation on broadened properties fuels. The concepts were based on the results of Phase 1 of the Broad Specification Fuel Combustor Technology Program which indicated that combustors with variable geometry or staged combustion zones had a flexibility of operation that could facilitate operation on these fuels. Emphasis in defining these concepts included the use of single pipe as opposed to duplex or staged fuels systems to avoid the risk of coking associated with the reduction in thermal stability expected in broadened properties fuels. The first concept was a variable geometry combustor in which the airflow into the primary zone could be altered through valves on the front while the second was an outgrowth of the staged Vorbix combustor, evolved under the NASA/P&W ECCP and EEE programs incorporating simplified fuel and air introduction. The results of the investigation, which involved the use of Experimental Referee Broad Specification (ERBS) fuel, indicated that in the form initially conceived, both of these combustor concepts were deficient in performance relative to many of the program goals for performance emissions. However, variations of both combustors were evaluated that incorporated features to simulate conceptual enhancement to demonstrate the long range potential of the combustor. In both cases, significant improvements relative to the program goals were observed.

  4. Fuel supply system for internal-combustion engine

    Microsoft Academic Search

    M. Fujieda; Y. Oyama

    1988-01-01

    This patent describes a fuel supply system for an internal-combustion engine. The fuel supply system consists of: fuel supply means; an intake-air passage connected through an intake valve to a combustion chamber defined by a cylinder and a piston, the intake-air passage having a volume between the fuel supply means and the intake valve means equal to a volume of

  5. Fundamental combustion studies of emulsified fuels. Annual progress report, October 1, 1979September 30, 1980

    Microsoft Academic Search

    1980-01-01

    A research program in the Fuels Research Laboratory at Princeton University has provided fundamental information on the combustion properties of emulsions and multi-component fuel mixtures. Particular attention has been given to understanding the phenomenon of micro-explosions and disruptive combustion. Earlier work which investigated the behavior of n-paraffin and water emulsions, binary mixtures of n-paraffins, and solutions of alcohol with n-paraffins

  6. IMPACT OF ALTERNATIVE FUELS ON SOOT PROPERTIES AND DPF REGENERATION

    Microsoft Academic Search

    JUHUN SONG; MAHABUBUL ALAM; ANDRÉ L. BOEHMAN

    2007-01-01

    In this work, fuel formulation exerted a strong influence on the properties of diesel particulates leading to differences in oxidation rate. These differences were especially significant when comparing soot derived from the combustion of soybean oil-derived biodiesel fuel (B100) and soot obtained from combustion of a Fischer–Tropsch diesel fuel (FT). These 2 fuels mainly differ in fuel oxygen content. Although

  7. Oxy-combustion of high water content fuels

    NASA Astrophysics Data System (ADS)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the spray were measured in the chamber for a stable flame. The experimental results indicate significant preferential vaporization of ethanol over water. Modeling results support this observation and indicate that the vaporization process is best described as the distillation limit mode with enhanced mass transfer by convection. Further, the influence of preferential vaporization on flame stability was investigated. A procedure was developed to evaluate the extent of preferential vaporization and subsequent flame stability of a fuel in aqueous solution. Various water soluble fuels were analyzed via this procedure in order to identify a chemical fuel showing strong preferential vaporization. t-Butanol was identified as having excellent physical and chemical properties, indicating stronger preferential vaporization than ethanol. Flame stability tests were run for aqueous solutions of both t-butanol and ethanol under identical flow conditions. Flame stability was characterized by the blow-off limit. In each comparison, the energy contents in the two solutions were kept the same. For the experiments under high swirl flow conditions (100% swirl flow), 12.5 wt% t-butanol has slightly lower blow-off limits than 15 wt% ethanol, and 8.3 wt% t-butanol has much lower blow-off limits than 10 wt% ethanol. For the experiments under a low swirl flow condition (50% swirl/50% axial flow), 12.5 wt% t-butanol has a much lower blow-off limit than 15 wt% ethanol. The time to release the fuel from a droplet was also calculated for both ethanol and t-butanol. For the same size droplet, the time to release t-butanol is much shorter than that of ethanol under the same conditions. Faster release of the fuel from water enhances flame stability, which is consistent with the experimental results. For the oxy-combustion characteristics of low-volatility fuel with high water content, glycerol was chosen as the fuel to study. It is found that self-sustained flame can be obtained for glycerol solution with concentration as high as 60 wt%, when burned in pure O2. However, the flame is lifted far away f

  8. Effect of fuel to oxidant molar ratio on particle size and LPG sensing properties of ZnO nanoparticles prepared by simple solution combustion method.

    NASA Astrophysics Data System (ADS)

    Naveen, C. S.; Rajeeva, M. P.; Lamani, Ashok R.; Deshmukh, P. R.; Lokhande, C. D.; Jayanna, H. S.

    2013-06-01

    ZnO nanoparticles of different size were prepared by varying the molar ratio of glycine and zinc nitrate hexahydrate as fuel and oxidizer (F/O molar ratio = 0.8, 1.11, 1.7) by simple solution combustion method. Powder samples were characterized by UV-Visible spectrophotometer, X-ray diffractometer (XRD), Scanning electron microscope (SEM). LPG sensing measurements were carried out in the temperature range 523-673K. It was found that, ZnO nanoparticle thick film prepared from F/O molar ratio 1.7 has maximum sensitivity of 5.20% for 520ppm of LPG at 623K compared to other thick films.

  9. New Findings on Combustion Behavior of Oxygenated Synthetic Diesel Fuels

    Microsoft Academic Search

    C. BEATRICE; C. BERTOLI; N. D. GIACOMO

    1998-01-01

    New results were obtained on pollutants evolution during the combustion of four oxygenated fuels, whichwere compared with n-tetradecane and n-octane combustion. Three different techniques were adopted on a single cylinder direct injection diesel engine, equipped with optical accesses: two-colour pyrometry for the measurement of in-cylinder soot loading, high speed cinematography for the visualization and analysis of spray and combustion, fast

  10. Characterizing fuels for atmospheric fluidized bed combustion

    SciTech Connect

    Marban, G.; Pis, J.J.; Fuertes, A.B. [CSIC, Oviedo (Spain). Instituto Nacional del Carbon] [CSIC, Oviedo (Spain). Instituto Nacional del Carbon

    1995-10-01

    A complete methodology for characterizing coal combustion in atmospheric fluidized bed reactors is presented. The methodology comprises studies of fragmentation and particle size variations during combustion, necessary to allow an accurate determination of kinetic parameters and attrition rates. Samples of three different carbonaceous materials (a medium-ash lignite, a medium-ash anthracite and a graphite) were pyrolyzed in N{sub 2} and partially burned in air in a bench-scale fluidized bed reactor at different operating conditions. The particle size distribution, apparent density and number of particles were evaluated by Image Analysis. Additionally, the sphericity factors were calculated. Combustion studies were carried out in batch experiments in the laboratory-scale, fluidized bed reactor at the same operating conditions. The reactor outlet concentrations of O{sub 2}, CO{sub 2}, and CO were monitored continuously. The results indicate that only anthracite particles experienced both primary (due to devolatilization) and secondary (during char combustion) fragmentation. Graphite particles underwent secondary fragmentation, whereas lignite particles did not significantly vary in number during combustion. Size and density variations during combustion suggest that graphite particles burn under regime II, interparticle diffusion being the rate controlling step. On the other hand, anthracite and lignite particles developed an ash layer, which may control combustion. The attrition constants of the medium-ash materials (lignite and anthracite) were found to be very low whereas that of graphite was much higher due mainly to peripheral percolation during combustion.

  11. Fuel system modifications to improve boiler combustion

    Microsoft Academic Search

    M. L. Crisler; P. A. Wagner

    1990-01-01

    A coal fired boiler for the Indian River Power Station has proven itself a reliable boiler. However, combustion problems have caused swings in tube metal temperatures, throttle pressure, flame carry over, and has resulted in high levels of unburned carbon in the bottom ash and flyash. A combustion improvement program was implemented to address these problems. Extensive testing and retrofit

  12. Experience with biomass fuel blends in combustion systems

    SciTech Connect

    Miles, T.R.; Miles, T.R. Jr. [Consulting Design Engineer, Portland, OR (United States)

    1996-12-31

    Biomass fuels often present economic opportunities and technical challenges for gasification and combustion. Supply and logistics of these fuels sometimes require them to be blended or cofired with other biomass fuels, coal or natural gas. Experience with blends of wood residues, grasses, straws, refuse, coal and tires fired in research and industrial gasifiers and combustion systems is presented. Effects on fuel quality, stoker or grate and handling systems, gasifier and burner design are described. Beneficial combinations are suggested for environmental and economical power generation. Impacts of fuel blending on ash disposal, air quality, corrosion, alkali deposits, and materials handling are delineated. Research and practical demonstrations are recommended for new fuel combinations or technologies.

  13. Effect of air distribution on solid fuel bed combustion

    SciTech Connect

    Kuo, J.T.; Hsu, W.S.; Yo, T.C. [National Taiwan Univ., Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

    1996-09-01

    One important aspect of refuse mass-burn combination control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g. bed height, bed voidage and bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, provide the most efficient combustion. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlations of combustion rate as functions of flue gas temperature and oxygen concentration. Despite the fact that the model is one dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed burning rates.

  14. Fuel/oxidizer-rich high-pressure preburners. [staged-combustion rocket engine

    NASA Technical Reports Server (NTRS)

    Schoenman, L.

    1981-01-01

    The analyses, designs, fabrication, and cold-flow acceptance testing of LOX/RP-1 preburner components required for a high-pressure staged-combustion rocket engine are discussed. Separate designs of injectors, combustion chambers, turbine simulators, and hot-gas mixing devices are provided for fuel-rich and oxidizer-rich operation. The fuel-rich design addresses the problem of non-equilibrium LOX/RP-1 combustion. The development and use of a pseudo-kinetic combustion model for predicting operating efficiency, physical properties of the combustion products, and the potential for generating solid carbon is presented. The oxygen-rich design addresses the design criteria for the prevention of metal ignition. This is accomplished by the selection of materials and the generation of well-mixed gases. The combining of unique propellant injector element designs with secondary mixing devices is predicted to be the best approach.

  15. Combustion characteristics of alternative gaseous fuels

    SciTech Connect

    Park, O.; Veloo, Peter S.; Liu, N.; Egolfopoulos, Fokion N.

    2011-01-01

    Fundamental flame properties of mixtures of air with hydrogen, carbon monoxide, and C{sub 1}–C{sub 4} saturated hydrocarbons were studied both experimentally and numerically. The fuel mixtures were chosen in order to simulate alternative gaseous fuels and to gain insight into potential kinetic couplings during the oxidation of fuel mixtures. The studies included the use of the counterflow configuration for the determination of laminar flame speeds, as well as extinction and ignition limits of premixed flames. The experiments were modeled using the USC Mech II kinetic model. It was determined that when hydrocarbons are added to hydrogen flames as additives, flame ignition, propagation, and extinction are affected in a counterintuitive manner. More specifically, it was found that by substituting methane by propane or n-butane in hydrogen flames, the reactivity of the mixture is reduced both under pre-ignition and vigorous burning conditions. This behavior stems from the fact that propane and n-butane produce higher amounts of methyl radicals that can readily recombine with atomic hydrogen and reduce thus the rate of the H + O{sub 2} ? O + OH branching reaction. The kinetic model predicts closely the experimental data for flame propagation and extinction for various fuel mixtures and pressures, and for various amounts of carbon dioxide in the fuel blend. On the other hand, it underpredicts, in general, the ignition temperatures.

  16. LOW NOX STRATEGY FOR COMBUSTING HIGH NITROGEN CONTENT FUELS

    EPA Science Inventory

    The report gives results of an evaluation of a multistaged combustion urner (designed for in-furnace NOx control and high combustion efficieiicy) for [high nitrogen content fuel and waste incineration application in a 1.0 MW package boiler. simulator. A low NOx precombustion cham...

  17. Combustion of hydrocarbon fuels within porous inert media

    Microsoft Academic Search

    J. R. Howell; M. J. Hall; J. L. Ellzey

    1996-01-01

    There has been a recent surge of interest in the combustion of hydrocarbon fuels within porous inert media. The interest has been directed by the needs of industry to develop high performance radiant heaters while complying with increasingly stringent emissions regulations. This paper reviews the processes associated with non-catalytic combustion within porous media, and describes related experimental and modeling research.

  18. Construction of combustion models for rapeseed methyl ester bio-diesel fuel for internal combustion engine applications.

    PubMed

    Golovitchev, Valeri I; Yang, Junfeng

    2009-01-01

    Bio-diesel fuels are non-petroleum-based diesel fuels consisting of long chain alkyl esters produced by the transesterification of vegetable oils, that are intended for use (neat or blended with conventional fuels) in unmodified diesel engines. There have been few reports of studies proposing theoretical models for bio-diesel combustion simulations. In this study, we developed combustion models based on ones developed previously. We compiled the liquid fuel properties, and the existing detailed mechanism of methyl butanoate ester (MB, C(5)H(10)O(2)) oxidation was supplemented by sub-mechanisms for two proposed fuel constituent components, C(7)H(16) and C(7)H(8)O (and then, by mp2d, C(4)H(6)O(2) and propyne, C(3)H(4)) to represent the combustion model for rapeseed methyl ester described by the chemical formula, C(19)H(34)O(2) (or C(19)H(36)O(2)). The main fuel vapor thermal properties were taken as those of methyl palmitate C(19)H(36)O(2) in the NASA polynomial form of the Burcat database. The special global reaction was introduced to "crack" the main fuel into its constituent components. This general reaction included 309 species and 1472 reactions, including soot and NO(x) formation processes. The detailed combustion mechanism was validated using shock-tube ignition-delay data under diesel engine conditions. For constant volume and diesel engine (Volvo D12C) combustion modeling, this mechanism could be reduced to 88 species participating in 363 reactions. PMID:19409477

  19. Method and apparatus for economizing fuel consumption in operating a multicylinder internal combustion engine

    Microsoft Academic Search

    Arrieta

    1984-01-01

    A method of economizing fuel consumption in operating an internal combustion engine having a group of combustion chambers of preselected numbers is disclosed. The method comprises the steps of consecutively introducing combustible fuel for ignition into each combustion chamber of the group to provide relatively high power availability for relatively high power demand, and of consecutively introducing combustible fuel for

  20. Fuel supply control method for internal combustion engines after starting

    Microsoft Academic Search

    A. Fujimura; Y. Wazaki

    1988-01-01

    This patent describes a method of controlling the supply of fuel to an internal combustion engine after starting thereof, including the steps of increasing a quantity of fuel to be supplied to the engine by the use of fuel increment after the starting of the engine, counting a period of time which elapses from the time a sensor for sensing

  1. Enhanced combustion by jet ignition in a turbocharged cryogenic port fuel injected hydrogen engine

    Microsoft Academic Search

    Alberto A. Boretti; Harry C. Watson

    2009-01-01

    The Hydrogen Assisted Jet Ignition (HAJI) is a physico-chemical combustion enhancement system developed at the University of Melbourne. Jet ignition can ignite ultra-lean air\\/fuel mixtures which are far beyond the stable ignition limit of a spark plug. Jet ignition may further enhance the combustion properties of hydrogen enabling the development of a diesel-like, almost throttle-less, control of load by quantity

  2. Co-combustion of recycled RDF and PDF fuels

    SciTech Connect

    Manninen, H. [Neste Oy Corporate Technology, Porvoo (Finland); Frankenhaeuser, M. [Borealis Polymers Oy, Porvoo (Finland)

    1996-12-31

    Energy recovery of used materials can be performed as mixed municipal solid waste (MSW) incineration or as fuel recovery for co-combustion. Recovered fuels are refuse derived fuel (RDF), which is mechanically separated and processed from MSW, and packaging derived fuel (PDF), which is the source separated, processed, dry combustible part of MSW. A one year co-combustion of RDF with peat and coal was carried out in a 65 MW CFB power plant at Kauttua, Finland. The efficiency of the combustion process and the corrosion behavior of the boiler were particular focuses of attention in this study. Five different PDFs were also co-combusted in the same power plant. A wide analytical program was carried out including the solid and gaseous emission measurements. Results were encouraging, showing that RDF and PDFs are technically and economically feasible and environmentally friendly fuels for co-combustion. Low CO emissions showed clean and efficient combustion. SO{sub 2} emissions decreased, because part of the coal was replaced by RDF and PDFs. HCl emissions increased when the chlorine content of the fuel mixture increase, because limestone injection was not used. Heavy metals concentrated to the fly ash in unleachable form. PCDD/F (dioxin) emissions were in the normal power plant level and far below the strictest incineration limit. Long-term co-combustion of 10% RDF did not cause any high temperature chlorine corrosion of the superheater materials (500 C). The results showed that it is useful and technically possible to combine resource and waste management in the form of fuel recovery and energy production in the normal power plants.

  3. Mild Combustion of Methane-Derived Fuel Mixtures: Natural Gas and Biogas

    Microsoft Academic Search

    Alessandro Effuggi; Davino Gelosa; Marco Derudi; Renato Rota

    2008-01-01

    Mild combustion (also called diluted or flameless combustion) is an innovative combustion process able to strongly reduce pollutant emissions with respect to traditional combustion processes; it is characterized by high preheating of the combustion air and massive recycle of burned gases. While it is well known that mild combustion leads to lowering NOx emissions when pure fuels (such as methane)

  4. Solid fuel combustion system for gas turbine engine

    DOEpatents

    Wilkes, Colin (Lebanon, IN); Mongia, Hukam C. (Carmel, IN)

    1993-01-01

    A solid fuel, pressurized fluidized bed combustion system for a gas turbine engine includes a carbonizer outside of the engine for gasifying coal to a low Btu fuel gas in a first fraction of compressor discharge, a pressurized fluidized bed outside of the engine for combusting the char residue from the carbonizer in a second fraction of compressor discharge to produce low temperature vitiated air, and a fuel-rich, fuel-lean staged topping combustor inside the engine in a compressed air plenum thereof. Diversion of less than 100% of compressor discharge outside the engine minimizes the expense of fabricating and maintaining conduits for transferring high pressure and high temperature gas and incorporation of the topping combustor in the compressed air plenum of the engine minimizes the expense of modifying otherwise conventional gas turbine engines for solid fuel, pressurized fluidized bed combustion.

  5. Hydrocarbon-fuel/combustion-chamber-liner materials compatibility

    NASA Technical Reports Server (NTRS)

    Gage, Mark L.

    1990-01-01

    Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.

  6. Compounded turbocharged rotary internal combustion engine fueled with natural gas

    SciTech Connect

    Jenkins, P.E.

    1992-10-15

    This patent describes a compounded engine. It comprises: a first Wankel engine having a housing with a trochoidal inner surface containing a generally triangular shaped rotor, the engine containing a fuel supply system suitable for operating the engine with natural gas as a fuel; a turbocharge compressing air for combustion by the engine, the turbocharger being driven by the exhaust gases which exit from the engine; a combustion chamber in fluid communication with the exhaust from the engine after that exhaust has passed through the turbocharger, the chamber having an ignition device suitable for igniting hydrocarbons in the engine exhaust, whereby the engine timing, and the air and fuel mixture of the engine are controlled so that when the engine exhaust reaches the combustion chamber the exhaust contains a sufficient amount of oxygen and hydrocarbons to enable ignition and combustion of the engine exhaust in the combustion chamber without the addition of fuel or air, and whereby the engine operating conditions are controlled to vary the performance of the secondary combustor; and a controllable ignition device to ignite the exhaust gases in the combustion chamber at predetermined times.

  7. A combustion model for IC engine combustion simulations with multi-component fuels

    SciTech Connect

    Ra, Youngchul; Reitz, Rolf D. [Engine Research Center, University of Wisconsin-Madison (United States)

    2011-01-15

    Reduced chemical kinetic mechanisms for the oxidation of representative surrogate components of a typical multi-component automotive fuel have been developed and applied to model internal combustion engines. Starting from an existing reduced mechanism for primary reference fuel (PRF) oxidation, further improvement was made by including additional reactions and by optimizing reaction rate constants of selected reactions. Using a similar approach to that used to develop the reduced PRF mechanism, reduced mechanisms for the oxidation of n-tetradecane, toluene, cyclohexane, dimethyl ether (DME), ethanol, and methyl butanoate (MB) were built and combined with the PRF mechanism to form a multi-surrogate fuel chemistry (MultiChem) mechanism. The final version of the MultiChem mechanism consists of 113 species and 487 reactions. Validation of the present MultiChem mechanism was performed with ignition delay time measurements from shock tube tests and predictions by comprehensive mechanisms available in the literature. A combustion model was developed to simulate engine combustion with multi-component fuels using the present MultiChem mechanism, and the model was applied to simulate HCCI and DI engine combustion. The results show that the present multi-component combustion model gives reliable performance for combustion predictions, as well as computational efficiency improvements through the use of reduced mechanism for multi-dimensional CFD simulations. (author)

  8. Fuel character effects on the J79 and F101 engine combustion systems

    NASA Technical Reports Server (NTRS)

    Jackson, T. A.

    1980-01-01

    The effects of select fuel property variations on two major engine classifications are summarized. Thirteen refined and blended fuels were used which exhibited significant variations in hydrogen content, aromatic type, initial boiling point, final boiling point, and viscosity. Trends were very similar but the degree of fuel sensitivity was not constant. For both systems the dominant fuel property during high pressure operation was found to be fuel hydrogen content. For operation at low pressure test points the fuel volatility and viscosity became the dominant fuel properties for both systems. Aromatic type and final boiling point did not significantly affect combustion data. Correlations of other fuel properties with these and other performance parameters are presented.

  9. EXPERIMENTAL COMBUSTION ANALYSIS OF A HSDI DIESEL ENGINE FUELLED WITH PALM OIL BIODIESEL-DIESEL FUEL BLENDS ANÁLISIS EXPERIMENTAL DE LA COMBUSTION DE UN MOTOR DIESEL DE AUTOMOCIÓN OPERANDO CON MEZCLAS DIESEL-BIODIESEL DE PALMA

    Microsoft Academic Search

    JOHN AGUDELO; ELKIN GUTIÉRREZ; PEDRO BENJUMEA

    2009-01-01

    Differences in the chemical nature between petroleum diesel fuels and vegetable oils-based fuels lead to differences in their physical properties affecting the combustion process inside the engine. In this work a detailed combustion diagnosis was applied to a turbocharged automotive diesel engine operating with neat palm oil biodiesel (POB), No. 2 diesel fuel and their blends at 20 and 50%

  10. Effect of additives on combustion of residual fuel oils

    SciTech Connect

    Korsakova, I.S.; Shor, G.I.; Shpiro, G.S.; Talisman, E.L.

    1982-11-01

    Uses an accelerated laboratory method to investigate the combustion process with drops of medium-sulfur residual fuel oils, and the effects of asphaltenes and additives on this process. Explains that one of the main goals in the use of medium-sulfur residual fuel oils in stationary and shipboard power plants is an increase in the completeness of combustion of these fuels, as this will result in smaller losses of fuel and lower levels of carbon deposit formation in boiler units and diesels. Finds that when additives are present, the fuel oils burn more intensely, owing to a change in the colloidal state of the asphaltenes; apparently, a reduction of the asphaltene particle size promotes their solubilization in the micellar structure of the fuel oil with the additive and promotes separation of the fuel oil into a ''light'' part and a coke residue. Points out that the more intense combustion also shows up in the greater brightness (higher temperature) of the flame, since when the additives are present, the height of the combustion curve on the recorder chart is greater; this reflects the catalytic effect on fuel hydrocarbon oxidation of the metals that are present in the additive (Fe, Mn, Cu, Al, etc.).

  11. FUEL RICH SULFUR CAPTURE IN A COMBUSTION ENVIRONMENT

    EPA Science Inventory

    A refractory-lined, natural gas furnace was used to study fuel rich sulfur capture reactions of calcium sorbents under typical combustion conditions. The fuel rich sulfur species H2S and COS were monitored in a near-continuous fashion using a gas chromatograph equipped with a fl...

  12. Fuel NOx pollution production during the combustion of a low caloric value fuel gas

    E-print Network

    Caraway, John Phillip

    1995-01-01

    FUEL NO, POLLUTION PRODUCTION DURING THE COMBUSTION OF A LOW CALORIC VALUE FUEL GAS A Thesis by JOHN PHILLIP CARAWAY Submitted to the Otftce of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1995 Major Subject: Mechanical Engineering FUEL NO, POLLUTION PRODUCTION DURING THE COMBUSTION OF A LOW CALORIC VALUE FUEL GAS A Thesis by JOHN PHILLIP CARAWAY Submitted to Texas ARM University in partial fulfillment...

  13. Combustion of dispersing porous monoblock fuels in a semiclosed volume

    Microsoft Academic Search

    A. N. Ishchenko; Yu. P. Khomenko; V. A. Burakov; D. A. Zimin

    2000-01-01

    Combustion of dispersing monoblock charges in a nozzle bomb were studied experimentally. Two mathematical models of different\\u000a complexity are proposed for the description of the processes. From a comparison of calculated and experimental time dependences\\u000a of the pressure in the bomb volume, effective laws of combustion and dispersion of the fuel are established and the dynamics\\u000a of the disperse mixture

  14. Generation of hypersonic liquid fuel jets accompanying self-combustion

    Microsoft Academic Search

    Hong-Hui Shi; Kazuyoshi Takayama

    1999-01-01

    .   Aerodynamic behavior of pulsed hypersonic light oil jets injected at 2 km\\/s and 3 km\\/s is presented. Auto-ignition and combustion\\u000a of the fuel during the injection process were visualized. The combustion around the disintegrating jet was enhanced by liquid\\u000a atomization created by the very high injection pressure as well as the interfacial instability of the hypersonic jet. The\\u000a jets

  15. Future Fuels for Internal Combustion Engines

    Microsoft Academic Search

    A. Demirbas

    2010-01-01

    Today the world is facing three critical problems: (1) high fuel prices, (2) climatic changes, and (3) air pollution. Experts suggest that current oil and gas reserves would suffice to last only a few more decades. Biorenewable liquids are the main substitutes to petroleum-based gasoline and diesel fuel. These fuels are important because they replace petroleum fuels; however, some still

  16. Method for controlling air\\/fuel ratio of fuel supply for an internal combustion engine

    Microsoft Academic Search

    A. Yasuoka; T. Kiuchi

    1987-01-01

    A method is described for controlling an air-fuel ratio of mixture to be supplied to an internal combustion engine having a fuel supply system, comprising the steps of: detecting whether or not an amount of the fuel to be supplied to the engine by means of the fuel supply system is greater than a reference amount; correcting the air-fuel ratio

  17. Method for controlling air\\/fuel ratio of fuel supply for an internal combustion engine

    Microsoft Academic Search

    A. Yamato; A. Fujimura

    1988-01-01

    A method is described for controlling an air\\/fuel ratio of mixture to be supplied to an internal combustion engine having a fuel supply system, comprising the steps of: detecting whether or not an amount of the fuel to be supplied to the engine by means of the fuel supply system is greater than a reference amount; correcting the air\\/fuel ratio

  18. Piston and process for achieving controlled ignition and combustion of hydrocarbon fuels in internal combustion engines by generation and management

    SciTech Connect

    Failla, C.C.; Pouring, A.A.; Rankin, B.; di Priolo, C.L.; Mc Cowan, W.; Gosewisch, D.

    1990-02-06

    This patent describes an improvement in a piston for a reciprocating piston internal combustion engine in which a combustion cycle is carried out in a variable volume combustion chamber defined by the piston reciprocating in a close ended cylinder into which a fuel and air charge is periodically supplied. The cycle includes intake, compression, combustion, expansion and exhaust portions. The piston crown is recessed and contains the majority of the charge when the combustion chamber is at minimum volume.

  19. Combustion of coal-gas fuels in a staged combustor

    SciTech Connect

    Rosfjord, T J; McVey, J B; Sederquist, R A; Schultz, D F

    1982-01-01

    Gaseous fuels produced from coal resources have been considered for use in industrial gas turbines. Such fuels generally have heating values much lower than the typical gaseous fuel, natural gas; the low heating value could result in unstable or inefficient combustion. Additionally, coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable NO/sub x/ exhaust emission levels. Previous investigations have indicated that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low NO/sub x/ emission operation for coal-derived liquid fuels containing up to 0.8-wt % nitrogen. An experimental program has been conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7% ammonia are presented. The test results permit the following conclusions to be drawn: (1) Staged, rich-lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with heating values of 210 kJ/mol (238 Btu/scf) or higher. (2) Lean combustion represents the desirable approach to achieve ultra-low NO/sub x/ and CO emissions for coal gas fuels with low heating values (84 kJ/mol (95 Btu/scf)). (3) Staged combustion has the ability to limit NH/sub 3/ to NO/sub x/ conversion rates to less than 5%. NO/sub x/ emissions below the EPA limit can readily be achieved.

  20. Alternate-Fueled Combustion-Sector Emissions

    NASA Technical Reports Server (NTRS)

    Saxena, Nikita T.; Thomas, Anna E.; Shouse, Dale T.; Neuroth, Craig; Hendricks, Robert C.; Lynch, Amy; Frayne, Charles W.; Stutrud, Jeffrey S.; Corporan, Edwin; Hankins, Terry

    2012-01-01

    In order to meet rapidly growing demand for fuel, as well as address environmental concerns, the aviation industry has been testing alternate fuels for performance and technical usability in commercial and military aircraft. Currently, alternate aviation fuels must satisfy MIL-DTL- 83133F(2008) (military) or ASTM D 7566- Annex(2011) (commercial) standards and are termed drop-in fuel replacements. Fuel blends of up to 50% alternative fuel blended with petroleum (JP-8), which have become a practical alternative, are individually certified on the market. In order to make alternate fuels (and blends) a viable option for aviation, the fuel must be able to perform at a similar or higher level than traditional petroleum fuel. They also attempt to curb harmful emissions, and therefore a truly effective alternate fuel would emit at or under the level of currently used fuel. This paper analyzes data from gaseous and particulate emissions of an aircraft combustor sector. The data were evaluated at various inlet conditions, including variation in pressure and temperature, fuel-to-air ratios, and percent composition of alternate fuel. Traditional JP-8+100 data were taken as a baseline, and blends of JP- 8+100 with synthetic-paraffinic-kerosene (SPK) fuel (Fischer-Tropsch (FT)) were used for comparison. Gaseous and particulate emissions, as well as flame luminosity, were assessed for differences between FT composition of 0%, 50%, and 100%. The data showed that SPK fuel (a FT-derived fuel) had slightly lower harmful gaseous emissions, and smoke number information corroborated the hypothesis that SPK-FT fuels are cleaner burning fuels.

  1. Combustion of coal gas fuels in a staged combustor

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.; Mcvey, J. B.; Sederquist, R. A.; Schultz, D. F.

    1982-01-01

    Gaseous fuels produced from coal resources generally have heating values much lower than natural gas; the low heating value could result in unstable or inefficient combustion. Coal gas fuels may contain ammonia which if oxidized in an uncontrolled manner could result in unacceptable nitrogen oxide exhaust emission levels. Previous investigations indicate that staged, rich-lean combustion represents a desirable approach to achieve stable, efficient, low nitrogen oxide emission operation for coal-derived liquid fuels contaning up to 0.8-wt pct nitrogen. An experimental program was conducted to determine whether this fuel tolerance can be extended to include coal-derived gaseous fuels. The results of tests with three nitrogen-free fuels having heating values of 100, 250, and 350 Btu/scf and a 250 Btu/scf heating value doped to contain 0.7 pct ammonia are presented.

  2. Apparatus and method for combusting low quality fuel

    DOEpatents

    Brushwood, John Samuel; Pillsbury, Paul; Foote, John; Heilos, Andreas

    2003-11-04

    A gas turbine (12) capable of combusting a low quality gaseous fuel having a ratio of flammability limits less than 2, or a heat value below 100 BTU/SCF. A high quality fuel is burned simultaneously with the low quality fuel to eliminate instability in the combustion flame. A sensor (46) is used to monitor at least one parameter of the flame indicative of instability. A controller (50) having the sensor signal (48) as input is programmed to control the relative flow rates of the low quality and high quality fuels. When instability is detected, the flow rate of high quality fuel is automatically increased in relation to the flow rate of low quality fuel to restore stability.

  3. Combustion system for dual fuel engine

    Microsoft Academic Search

    F. S. Schaub; J. G. Smith

    1990-01-01

    This patent describes in an dual gas-liquid fuel four cycle engine having cylinders and wherein each cylinder is operatively connected thereto and each cylinder has a piston, two inlet valves, two exhaust valves and a first liquid fuel injector. It comprises: at least one fuel torch cell operatively connected to at least one cylinder, the torch cell having a torch

  4. Dynamic stability, blowoff, and flame characteristics of oxy-fuel combustion

    E-print Network

    Shroll, Andrew Philip

    2011-01-01

    Oxy-fuel combustion is a promising technology to implement carbon capture and sequestration for energy conversion to electricity in power plants that burn fossil fuels. In oxy-fuel combustion, air separation is used to ...

  5. Combustion Properties of Biomass Flash Pyrolysis Oils: Final Project Report

    SciTech Connect

    C. R. Shaddix; D. R. Hardesty

    1999-04-01

    Thermochemical pyrolysis of solid biomass feedstocks, with subsequent condensation of the pyrolysis vapors, has been investigated in the U.S. and internationally as a means of producing a liquid fuel for power production from biomass. This process produces a fuel with significantly different physical and chemical properties from traditional petroleum-based fuel oils. In addition to storage and handling difficulties with pyrolysis oils, concern exists over the ability to use this fuel effectively in different combustors. The report endeavors to place the results and conclusions from Sandia's research into the context of international efforts to utilize pyrolysis oils. As a special supplement to this report, Dr. Steven Gust, of Finland's Neste Oy, has provided a brief assessment of pyrolysis oil combustion research efforts and commercialization prospects in Europe.

  6. NASA Broad-Specification Fuels Combustion Technology Program - Status and description

    NASA Technical Reports Server (NTRS)

    Fear, J. S.

    1980-01-01

    The use of 'broad-specification' fuels in aircraft gas turbine engines can be a significant factor in offsetting anticipated shortages of current-specification jet fuel in the latter part of the century. The changes in fuel properties accompanying the use of broad-specification fuels will tend to cause numerous emissions, performance, and durability problems in currently-designed combustion systems. The NASA Broad-Specification Fuels Combustion Technology Program is a contracted effort to evolve and demonstrate the technology required to utilize broad-specification fuels in current and next generation commercial Conventional Takeoff and Landing (CTOL) aircraft engines, and to verify this technology in full-scale engine tests in 1983. The program consists of three phases: Combustor Concept Screening, Combustor Optimization Testing, and Engine Verification Testing.

  7. Liquid fuel combustion within silicon-carbide coated carbon foam

    SciTech Connect

    Vijaykant, S.; Agrawal, Ajay K. [Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL 35487 (United States)

    2007-10-15

    Combustion of kerosene inside porous inert medium (PIM) has been investigated with the goal of reducing the emissions of nitric oxides (NO{sub x}), carbon monoxide (CO) and soot. Silicon-carbide (SiC) coated carbon foam is used as PIM to attain high structural strength. The two-zone porous burner design consists of preheat and combustion sections. Different PIM configurations were tested by stacking together square porous pieces of 2.5 cm thickness. Two types of fuel injectors are considered: (i) in the air-assist injector, approximately 5% of the combustion air is used for atomization and the remaining air enters as the primary co-flow around the injector, and (ii) in the swirling-air injector, all of the combustion air enters the injector to create a swirling flow around the fuel jet to enhance atomization and fuel-air premixing. The distance between the injector and PIM inlet is a key operational parameter, which was varied in experiments with both injectors over a range of equivalence ratios and heat release rates. The NO{sub x} and CO emissions were measured to optimize the PIM configuration with minimum emissions. Results show stable combustion over a wide operating range. Three combustor operational regimes are identified depending upon the injector location. (author)

  8. Combustion of liquid fuels in diesel engine

    NASA Technical Reports Server (NTRS)

    Alt, Otto

    1924-01-01

    Hitherto, definite specifications have always been made for fuel oils and they have been classified as more or less good or non-utilizable. The present aim, however, is to build Diesel engines capable of using even the poorest liquid fuels and especially the waste products of the oil industry, without special chemical or physical preparation.

  9. ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal

    E-print Network

    Laughlin, David E.

    ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal Gordon R. Holcomb · Joseph Tylczak-fuel combustion is burning a fuel in oxygen rather than air for ease of capture of CO2 from for reuse between 10-4 and 10-3 atm of SO3 at 700 °C. Keywords Fireside corrosion Á Oxidation Á Oxy-fuel combustion

  10. INFERIOR FUELS OIL SIMULATED COMBUSTION TESTING, AS EQUIVALENT NDT

    Microsoft Academic Search

    V. Ghiea

    Especially it is proposed a simulated combustion testing (SCT) for miniaturised inferior fuel oil (IFO) with exemplifications of advantageous validity verification at large boilers, as equivalent nondestructive testing (NDT) for industry. This type of testing can generates a new very profitable direction for the 16-th World Conference on NDT activity. It is detailly presented the industrial symbiotic technologies improvement, as

  11. Method and apparatus for hydrogen fueled internal combustion engines

    Microsoft Academic Search

    Billings

    1976-01-01

    The hydrogen engine described introduces water as vapor with inlet hydrogen and air, as a mixture proportioned for practical internal combustion and efficient power output. Water vapor is a substantial component of the exhaust of hydrogen fueled engines. In one embodiment of the invention, water vapor is condensed from the exhaust, and thereupon arranged to provide the input water as

  12. Introduction Fossil fuel combustion by aviation, shipping and road

    E-print Network

    Haak, Hein

    96 Introduction Fossil fuel combustion by aviation, shipping and road traffic contributes about one. The total climate impact of aviation emissions (excluding the uncertain impact on natural clouds of the aviation sector has already been assessed quite extensively, e.g. in the IPCC special Report on Aviation

  13. Method and system for low-NO.sub.x dual-fuel combustion of liquid and/or gaseous fuels

    DOEpatents

    Gard, Vincent; Chojnacki, Dennis A; Rabovitser, Ioseph K

    2014-12-02

    A method and apparatus for combustion in which a pressurized preheated liquid fuel is atomized and a portion thereof flash vaporized, creating a mixture of fuel vapor and liquid droplets. The mixture is mixed with primary combustion oxidant, producing a fuel/primary oxidant mixture which is then injected into a primary combustion chamber in which the fuel/primary oxidant mixture is partially combusted, producing a secondary gaseous fuel containing hydrogen and carbon oxides. The secondary gaseous fuel is mixed with a secondary combustion oxidant and injected into the second combustion chamber wherein complete combustion of the secondary gaseous fuel is carried out. The resulting second stage flue gas containing very low amounts of NO.sub.x is then vented from the second combustion chamber.

  14. Combustion of anaerobically digested humus as a fuel

    SciTech Connect

    Kayhanian, M.; Jenkins, B.M. [Univ. of California, Davis, CA (United States); Baxter, L.L. [Sandia National Labs., Livermore, CA (United States)] [and others

    1994-12-31

    Two pilot scale combustion experiments were conducted to explore the application of an anaerobically digested humus as fuel for commercial boilers. The experiments were performed in a fluidized bed combustor (FBC) and a multifuel suspension combustor (MFC). The results obtained indicate that the humus, blended with another conventional fuel (e.g., wood), can be used as a fuel in commercial boilers. Preliminary results of ash deposit analyses from the MFC indicate that the rate of deposition was low compared to high fouling biomass fuels such as straws, and similar to deposits obtained from wood.

  15. Combustion test of SRC-oil mixture technical study on SOM fuel for oil-fired power plant. Final report

    Microsoft Academic Search

    H. Mizuochi; M. Sato; T. Sema; K. Endo; Y. Hasegawa; M. Makino; T. Ninomiya; T. Ono; Y. Ishihara

    1982-01-01

    SRC (Solvent Refined Coal) was chosen as one of the efficient substances for coal utilization. Properties, combustion characteristics, and flue gas properties of SOM (SRC-Oil Mixture) fuel have been investigated for applicability to power generation. Results of the investigation are summarized and the conversion of heavy fuel oil to SOM fuel at the existing heavy-fuel oil-fired power plants is discussed.

  16. Modelin combustion of multicomponent fuel droplets: formulation and application to transportation fuels 

    E-print Network

    Vittilapuram Subramanian, Kannan

    2006-04-12

    The quasi-steady, spherically symmetric combustion of multicomponent isolated fuel droplets has been modeled using modified Shvab-Zeldovich variable mechanism. Newly developed modified Shvab-Zeldovich equations have been used to describe the gas...

  17. Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines (Poster)

    SciTech Connect

    Taylor, J.; Li, H.; Neill, S.

    2006-08-01

    The objective of this report is to develop a pathway to use easily measured ignition properties as metrics for characterizing fuels in advanced combustion engine research--correlate IQT{trademark} measured parameters with engine data. In HCCL engines, ignition timing depends on the reaction rates throughout compression stroke: need to understand sensitivity to T, P, and [O{sub 2}]; need to rank fuels based on more than one set of conditions; and need to understand how fuel composition (molecular species) affect ignition properties.

  18. Catalytic combustion of heavy partially-vaporized fuels

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1980-01-01

    An experimental program to demonstrate efficient catalytic combustion of fuel-lean and fuel-rich mixtures of residual fuel and air, and to assess the influence of incomplete fuel vaporization on the performance of a catalytic reactor is being conducted. A 7.5-cm diameter catalytic reactor was designed and will be tested over a matrix of conditions representative of a gas turbine combustor inlet. For each of three test phases, two series of tests with a uniform but poorly vaporized (less than 50 percent) mixture of No. 6 fuel oil and air will be performed. In the first series, the non-vaporized fuel will be contained in a spray of droplets with a Sauter Mean Diameter (SMD) less than 30 microns. In the second series, the non-vaporized fuel will be characterized by a spray SMD approximately equal to 100 microns. The designs of the fuel injection system and the catalytic reactor are described in this paper.

  19. Numerical modeling of hydrogen-fueled internal combustion engines

    SciTech Connect

    Johnson, N.L.; Amsden, A.A.; Butler, T.D. [Los Alamos National Lab., NM (United States). Theoretical Div.

    1996-07-01

    Major progress was achieved in the last year in advancing the modeling capabilities of hydrogen-fueled engines, both in support of the multi-laboratory project with SNL and LLNL to develop a high-efficiency, low emission powerplant and to provide the engine design tools to industry and research laboratories for hydrogen-fueled engines and stationary power generators. The culmination of efforts on many fronts was the excellent comparison of the experimental data from the Onan engine, operated by SNL.These efforts include the following. An extensive study of the intake flow culminated in a major understanding of the interdependence of the details of the intake port design and the engine operating condition on the emissions and efficiency. This study also resulted in design suggestions for future engines and general scaling laws for turbulence that enables the KIVA results to be applied to a wide variety of operating conditions. The research on the turbulent combustion of hydrogen brought into perspective the effect of the unique aspects of hydrogen combustion and their influence on possible models of turbulent combustion. The effort culminated in a proposed model for turbulent hydrogen combustion that is in agreement with available literature. Future work will continue the development in order to provide a generally predictive model for hydrogen combustion. The application of the combustion model to the Onan experiments elucidated the observed improvement of the efficiency of the engine with the addition of a shroud on the intake valve. This understanding will give guidance to future engine design for optimal efficiency. Finally, a brief summary is given of the extensions and refinements of the KIVA-3 code, in support of future designers of hydrogen-fueled engines.

  20. Explosively Driven Combustion of Shock-Dispersed Fuels

    NASA Astrophysics Data System (ADS)

    Neuwald, P.

    2006-07-01

    The paper presents small-scale experiments with 1-g charges that explore the topic of post-detonation energy release due to the combustion of explosively dispersed fuels in the ambient air. To this end we have designed a new prototype small-scale charge, called Shock-Dispersed Fuel (SDF) charge. It consists of a lightweight, small paper cylinder filled with about one gram of a combustible powder (e.g., flake aluminum) surrounding a spherical PETN booster of 0.5 g. We have tested the SDF charges in a number of different environments, realized as closed steel vessels of simple geometry (barometric bombs). Three of the bombs vary in volume (6.6 1, 21.2 1 and 40.5 1), while their aspect ratio L/D is kept constant at about 1. Two further bombs are comparable to the smallest bomb in volume (6.3 1), but provide different aspect ratios: L/D = 4.6 and 12.5. In addition, we have also performed tests in a tunnel-model with an L/D = 37.5. Our basic goal is to assess the performance of the charges by means of the combustion-related pressure built-up. Thus we contrast experiments on SDF charges in air with tests in nitrogen, to inhibit combustion, and with tests on conventional charges. Experiments and theoretical estimates on the expected overpressure allow one to formulate various indicators of the combustion effectiveness. For SDF charges these indicate that the combustion effectiveness decreases with increasing volume of the barometric bomb, and also with increasing aspect ratio at constant volume. This bears importance to the performance of SDF charges in tunnel environments. The performance losses reflect — at least in part — geometry-specific constraints on the mixing between fuel and air.

  1. Hydrogen-fueled internal combustion engines

    Microsoft Academic Search

    Sebastian Verhelst; Thomas Wallner

    2009-01-01

    The threat posed by climate change and the striving for security of energy supply are issues high on the political agenda these days. Governments are putting strategic plans in motion to decrease primary energy use, take carbon out of fuels and facilitate modal shifts.Taking a prominent place in these strategic plans is hydrogen as a future energy carrier. A number

  2. Fuel injector nozzle for an internal combustion engine

    DOEpatents

    Cavanagh, Mark S. (Bloomington, IL); Urven, Jr., Roger L. (Colona, IL); Lawrence, Keith E. (Peoria, IL)

    2011-03-22

    A direct injection fuel injector includes a nozzle tip having a plurality of passages allowing fluid communication between an inner nozzle tip surface portion and an outer nozzle tip surface portion and directly into a combustion chamber of an internal combustion engine. A first group of the passages have inner surface apertures located substantially in a first common plane. A second group of the passages have inner surface apertures located substantially in at least a second common plane substantially parallel to the first common plane. The second group has more passages than the first group.

  3. Fuel injector nozzle for an internal combustion engine

    DOEpatents

    Cavanagh, Mark S. (Bloomington, IL); Urven, Jr., Roger L. (Colona, IL); Lawrence, Keith E. (Peoria, IL)

    2008-11-04

    A direct injection fuel injector includes a nozzle tip having a plurality of passages allowing fluid communication between an inner nozzle tip surface portion and an outer nozzle tip surface portion and directly into a combustion chamber of an internal combustion engine. A first group of the passages have inner surface apertures located substantially in a first common plane. A second group of the passages have inner surface apertures located substantially in at least a second common plane substantially parallel to the first common plane. The second group has more passages than the first group.

  4. Fuel injector nozzle for an internal combustion engine

    DOEpatents

    Cavanagh, Mark S. (Bloomington, IL); Urven, Jr., Roger L. (Colona, IL); Lawrence, Keith E. (Peoria, IL)

    2007-11-06

    A direct injection fuel injector includes a nozzle tip having a plurality of passages allowing fluid communication between an inner nozzle tip surface portion and an outer nozzle tip surface portion and directly into a combustion chamber of an internal combustion engine. A first group of the passages have inner surface apertures located substantially in a first common plane. A second group of the passages have inner surface apertures located substantially in at least a second common plane substantially parallel to the first common plane. The second group has more passages than the first group.

  5. Fuel Injector Nozzle For An Internal Combustion Engine

    DOEpatents

    Cavanagh, Mark S. (Bloomington, IL); Urven, Jr.; Roger L. (Colona, IL); Lawrence, Keith E. (Peoria, IL)

    2006-04-25

    A direct injection fuel injector includes a nozzle tip having a plurality of passages allowing fluid communication between an inner nozzle tip surface portion and an outer nozzle tip surface portion and directly into a combustion chamber of an internal combustion engine. A first group of the passages have inner surface apertures located substantially in a first common plane. A second group of the passages have inner surface apertures located substantially in at least a second common plane substantially parallel to the first common plane. The second group has more passages than the first group.

  6. Disturbing effect of free hydrogen on fuel combustion in internal combustion engines

    NASA Technical Reports Server (NTRS)

    Riedler, A

    1923-01-01

    Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots.

  7. Hybrid rocket fuel combustion and regression rate study

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  8. Kinetic Modeling of Combustion Characteristics of Real Biodiesel Fuels

    SciTech Connect

    Naik, C V; Westbrook, C K

    2009-04-08

    Biodiesel fuels are of much interest today either for replacing or blending with conventional fuels for automotive applications. Predicting engine effects of using biodiesel fuel requires accurate understanding of the combustion characteristics of the fuel, which can be acquired through analysis using reliable detailed reaction mechanisms. Unlike gasoline or diesel that consists of hundreds of chemical compounds, biodiesel fuels contain only a limited number of compounds. Over 90% of the biodiesel fraction is composed of 5 unique long-chain C{sub 18} and C{sub 16} saturated and unsaturated methyl esters. This makes modeling of real biodiesel fuel possible without the need for a fuel surrogate. To this end, a detailed chemical kinetic mechanism has been developed for determining the combustion characteristics of a pure biodiesel (B100) fuel, applicable from low- to high-temperature oxidation regimes. This model has been built based on reaction rate rules established in previous studies at Lawrence Livermore National Laboratory. Computed results are compared with the few fundamental experimental data that exist for biodiesel fuel and its components. In addition, computed results have been compared with experimental data for other long-chain hydrocarbons that are similar in structure to the biodiesel components.

  9. Gasoline Ultra Efficient Fuel Vehicle with Advanced Low Temperature Combustion

    SciTech Connect

    Confer, Keith

    2014-09-30

    The objective of this program was to develop, implement and demonstrate fuel consumption reduction technologies which are focused on reduction of friction and parasitic losses and on the improvement of thermal efficiency from in-cylinder combustion. The program was executed in two phases. The conclusion of each phase was marked by an on-vehicle technology demonstration. Phase I concentrated on short term goals to achieve technologies to reduce friction and parasitic losses. The duration of Phase I was approximately two years and the target fuel economy improvement over the baseline was 20% for the Phase I demonstration. Phase II was focused on the development and demonstration of a breakthrough low temperature combustion process called Gasoline Direct- Injection Compression Ignition (GDCI). The duration of Phase II was approximately four years and the targeted fuel economy improvement was 35% over the baseline for the Phase II demonstration vehicle. The targeted tailpipe emissions for this demonstration were Tier 2 Bin 2 emissions standards.

  10. Synthesis of Diopside by Solution Combustion Process Using Glycine Fuel

    NASA Astrophysics Data System (ADS)

    Sherikar, Baburao N.; Umarji, A. M.

    Nano ceramic Diopside (CaMgSi2O6) powders are synthesized by Solution Combustion Process(SCS) using Calcium nitrate, Magnesium nitrate as oxidizer and glycine as fuel, fumed silica as silica source. Ammonium nitrate (AN) is used as extra oxidizer. Effect of AN on Diopside phase formation is investigated. The adiabatic flame temperatures are calculated theoretically for varying amount of AN according to thermodynamic concept and correlated with the observed flame temperatures. A “Multi channel thermocouple setup connected to computer interfaced Keithley multi voltmeter 2700” is used to monitor the thermal events during the process. An interpretation based on maximum combustion temperature and the amount of gases produced during reaction for various AN compositions has been proposed for the nature of combustion and its correlation with the characteristics of as synthesized powder. These powders are characterized by XRD, SEM showing that the powders are composed of polycrystalline oxides with crystallite size of 58nm to 74nm.

  11. Speciated Hydrocarbon Emissions from the Combustion of Single Component Fuels. I. Effect of Fuel Structure

    Microsoft Academic Search

    W. O. Siegel; R. W. McCabe; W. Chun; E. W. Kaiser; J. Perry; Y. I. Henig; F. H. Trinker; R. W. Anderson

    1992-01-01

    Speciated hydrocarbon emissions data have been collected for six single-component fuels run in a laboratory pulse flame combustor (PFC). The six fuels include n-heptane, isooctane (2, 2, 4-trimethylpentane), cyclohexane, 1-hexene, toluene, and methyl-t-butyl ether (MTBE: an oxygenated fuel extender). Combustion of non-aromatic fuels in the PFC (at a fuel\\/air equivalence ratio of ? = 1.02) produced low levels of unburned

  12. Investigation of trapped vortex combustion using hydrogen-rich fuels

    NASA Astrophysics Data System (ADS)

    Zbeeb, Khaled

    The combustion process of a fuel is a challenging subject when it comes to analyze its performance and resultant emissions. The main task of this study is to optimize the selection of a hydrogen-rich fuel based on its performance and emissions. Computational Fluid Dynamics analysis is performed to test the combustion performance and emissions from the vortex trapped combustor when natural gas fuel (methane) is replaced with renewable and alternative fuels such as hydrogen and synthesis gas. Correlation graphs for the trapped vortex combustor performance and NOx, CO, and CO2 emissions for various types of fuels with different compositions and heat of combustion values were established. Methane, Hydrogen and 10 different syngas fuels were analyzed in this study using computational fluid dynamics numerical method. The trapped vortex combustor that represents an efficient and compact combustor for flame stability was investigated. The TVC consists of a fore body and two after body disks. These components are all encircled with a Pyrex tube. The purpose of the after body disks is to create the vortex wakes that will enhance the combustion process and minimize the NOx emissions. The TVC CFD model was validated by comparing the CFD model results using propane fuel with existing experimental results that were established in Rome, Italy. The static temperature distribution and NOx, CO emissions, combustor efficiency and total pressure drop results of the three dimensional CFD model were similar to the experimental data. Effects of H2/CO and H2/CH4 ratios and the mass fraction of each constituent of syngas fuels and Hydrogen-Methane fuel mixture on the TVC performance and emissions were investigated. Moreover, the fuel injector Reynolds number and Lower heating values for Methane, Hydrogen and 10 syngas fuels on the TVC performance and emissions were also investigated. Correlation plots for the NOx, CO and CO2 emissions versus the fuel injector Reynolds number and lower heating value were established. These correlation curves can be used as a fair design diagram to optimize the fuel selection process for aerospace and electrical power plant applications.

  13. Radiation properties of coal combustion products

    SciTech Connect

    Im, K.H.; Ahluwalia, R.K.

    1990-11-01

    An assessment is made of the experimental data and the theoretical bases for determining the absorption and scattering coefficients of the coal products of combustion. Particular attention is devoted to the complex refractive indices for char and ash. A dispersion relation is developed from sparse extinction data that can be used to estimate the optical constants of char. Considerable uncertainty and scatter is found in the literature data on ash optical constants and is attributed to variability in ash composition, lack of experimental rigor and limitations in the data reduction procedures. A correlation is presented for estimating the complex refractive indices of ash as a function of its mineral composition. A parametric study is conducted to elucidate the role of char, soot and ash particulates in determining the radiation properties of coal flames. The effects of combustion particulates are discussed in terms of the modification of the band structure of gas radiation to a luminous spectrum, introduction of scattering in radiation transport, particle size distribution, particle loading and particle composition. The results are interpreted as possible effects of coal beneficiation, coal micronization and flyash composition on heat transfer to the water walls of a coal furnace. 19 refs., 13 figs., 10 tabs.

  14. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Monitoring of emissions and operations for fuel gas combustion devices. 60.107a Section 60.107a...Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2...

  15. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Monitoring of emissions and operations for fuel gas combustion devices. 60.107a Section 60.107a...Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2...

  16. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Monitoring of emissions and operations for fuel gas combustion devices. 60.107a Section 60.107a...Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2...

  17. Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California

    E-print Network

    Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California Estimates from the Combustion of Fossil Fuels in California" and augmentation to contract number 05 Dioxide Emission Estimates from the Combustion of Fossil Fuels in California" and augmentation to contract

  18. Analysis of fuel vaporization, fuel/air mixing, and combustion in lean premixed/prevaporized combustors

    SciTech Connect

    Deur, J.M. [NYMA, Inc., Brook Park, OH (United States); Penko, P.F. [National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center; Cline, M.C. [Los Alamos National Lab., NM (United States)

    1995-07-01

    Requirements to reduce pollutant emissions from gas turbines used in aircraft propulsion and ground-based power generation have led to consideration of lean premixed/prevaporized (LPP) combustion concepts. This paper describes a series of the LPP combustor analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. Modifications to KIVA-II`s boundary condition and chemistry treatments have been made to meet the needs of the present study. The study examines the relationships between fuel vaporization, fuel/air mixing, and combustion in a generic LPP combustor. Parameters considered include: mixer tube diameter, mixer tube length, mixer tube configuration (straight versus converging/diverging tubes), air inlet velocity, air inlet swirl angle, secondary air injection (dilution holes), fuel injection velocity, fuel injection angle, number of fuel injection ports, fuel spray cone angle, and fuel droplet size. Cases have been run with and without combustion to examine the variations in fuel/air mixing and potential for flashback due to the above parameters. The degree of fuel/air mixing is judged by comparing average, minimum, and maximum fuel/air ratios at the exit of the mixer tube, while flame stability is monitored by following the location of the flame front as the solution progresses from ignition to steady state.

  19. Combustion instabilities in sudden expansion oxy-fuel flames

    SciTech Connect

    Ditaranto, Mario; Hals, Joergen [Department of Energy Processes, SINTEF Energy Research, 7465 Trondheim (Norway)

    2006-08-15

    An experimental study on combustion instability is presented with focus on oxy-fuel type combustion. Oxidants composed of CO{sub 2}/O{sub 2} and methane are the reactants flowing through a premixer-combustor system. The reaction starts downstream a symmetric sudden expansion and is at the origin of different instability patterns depending on oxygen concentration and Reynolds number. The analysis has been conducted through measurement of pressure, CH* chemiluminescence, and velocity. As far as stability is concerned, oxy-fuel combustion with oxygen concentration similar to that found in air combustion cannot be sustained, but requires at least 30% oxygen to perform in a comparable manner. Under these conditions and for the sudden expansion configuration used in this study, the instability is at low frequency and low amplitude, controlled by the flame length inside the combustion chamber. Above a threshold concentration in oxygen dependent on equivalence ratio, the flame becomes organized and concentrated in the near field. Strong thermoacoustic instability is then triggered at characteristic acoustic modes of the system. Different modes can be triggered depending on the ratio of flame speed to inlet velocity, but for all types of instability encountered, the heat release and pressure fluctuations are linked by a variation in mass-flow rate. An acoustic model of the system coupled with a time-lag-based flame model made it possible to elucidate the acoustic mode selection in the system as a function of laminar flame speed and Reynolds number. The overall work brings elements of reflection concerning the potential risk of strong pressure oscillations in future gas turbine combustors for oxy-fuel gas cycles. (author)

  20. Experimental investigation of fuel vaporization on combustion efficiency

    SciTech Connect

    Zakkay, V.; Agnone, A.; Clisset, H.

    1980-12-01

    The development of a residential size vaporizing oil burner is presented along with its operational and performance characteristics. The vaporization scheme consists of spraying No. 2 oil onto a regeneratively heated surface at a temperature above the oil vaporization temperature (650/sup 0/F). The vaporized oil mixes with a preheated air (T = 250/sup 0/F) stream to produce a uniform fuel air mixture. The premixed vaporized fuel/air stream produces short blue flamelets anchored to a steel screen flame holder. The operational and performance characteristics of this burner are presented for a range of the air and oil flow parameters around the stoichiometric condition, and for a nominal firing rate of less than or equal to 1.2 gph. Operation with less than 3% excess air is demonstrated with very little soot formation. The combustion quality of the vaporizing oil burner is substantially improved compared to conventional spray combustion and recirculation type blue flame burners. The vaporizing oil burner was adapted to a conventional boiler and the thermal efficiency was determined by a calorimeter technique and compared to the stack method. The thermal efficiency with the vaporized combustion mode is about 4% greater than conventional spray combustion burners. The increase is realized through the reduced excess air requirements. The increased efficiency can result in reduced oil consumption from 12% to 20% depending on the location and usage of the burner unit.

  1. Combustion chemistry and an evolving transportation fuel environment.

    SciTech Connect

    Taatjes, Craig A. (Org. 8353, Combustion Chemistry Department)

    2010-05-01

    The world currently faces tremendous energy challenges stemming from the need to curb potentially catastrophic anthropogenic climate change. In addition, many nations, including the United States, recognize increasing political and economic risks associated with dependence on uncertain and limited energy sources. For these and other reasons the chemical composition of transportation fuels is changing, both through introduction of nontraditional fossil sources, such as oil sands-derived fuels in the US stream, and through broader exploration of biofuels. At the same time the need for clean and efficient combustion is leading engine research towards advanced low-temperature combustion strategies that are increasingly sensitive to this changing fuel chemistry, particularly in the areas of pollutant formation and autoignition. I will highlight the new demands that advanced engine technologies and evolving fuel composition place on investigations of fundamental reaction chemistry. I will focus on recent progress in measuring product formation in elementary reactions by tunable synchrotron photoionization, on the elucidation of pressure-dependent effects in the reactions of alkyl and substituted alkyl radicals with O{sub 2}, and on new combined efforts in fundamental combustion chemistry and engine performance studies of novel potential biofuels.

  2. Fuel correlations for combustion purposes, a summary of progress within the past fifteen years. Part 2

    SciTech Connect

    Kretschmer, D.; Odgers, J. [Laval Univ., Quebec City, Quebec (Canada). Dept. of Mechanical Engineering

    1996-12-31

    Over the years, many correlations for fuel properties have been developed at Laval University. The main goal in this was to provide tools to estimate unknown fuel properties from the known values of the density and the viscosity at one temperature and the ASTM D-86 distillation, since these data are easily determined. The first part of this paper dealt with properties of liquid fuels. Most of the correlations in this second part are not so much pertinent to fuel properties per se, but rather to lean premixed flame behavior. Much of the behavior is related to two postulated temperatures, T{sub auig} and T{sub i}. The first (the auto ignition temperature) may be regarded as the start of a reaction and the second (the instantaneous, spontaneous ignition temperature) may be regarded as that temperature at which the reaction first becomes self-sustaining. Between them they account for a good deal of premixed combustion behavior. 48 refs.

  3. Evaluation of Planck mean coefficients for particle radiative properties in combustion environments

    NASA Astrophysics Data System (ADS)

    Hofgren, Henrik; Sundén, Bengt

    2015-04-01

    Thermal radiation is the dominating form of heat transfer in several combustion technologies that combust solid fuels, such as pulverized coal combustion and fixed bed combustion. The thermal radiation originates from the hot combustion gases and particles. For accurate modelling of thermal radiation in these environments the selection of the radiative transport model and radiative property model is important. Radiative property models for gases have received huge attention and several well documented models exist. For particles, soot has received considerable attention whereas other particles have not to a similar extent. The Planck mean coefficients are most commonly used to describe the radiative properties of the particles. For gases the Planck mean absorption coefficient is known to give large deviations from recognised exact models in predicting the radiative heat transfer. In this study the use of Planck mean coefficients for particles are investigated and compared to spectral models. Two particle mass size distributions of fly ash are used, representing biomass and coal combustion. The evaluation is conducted in several combustion-like test cases with both gases and particles. The evaluation shows that using Planck mean coefficients for particles, in combustion-like situations, can give large errors in predicting the radiative heat flux and especially the source term. A new weighted sum of grey gas approach is tested and evaluated. It includes both the particles and gases to better account for the non-greyness of the fly ash absorption coefficient.

  4. Enhancing the combustible properties of bamboo by torrefaction.

    PubMed

    Rousset, Patrick; Aguiar, Clarissa; Labbé, Nicole; Commandré, Jean-Michel

    2011-09-01

    Bamboo has wide range of moisture content, low bulk energy density and is difficult to transport, handle, store and feed into existing combustion and gasification systems. Because of its important fuel characteristics such as low ash content, alkali index and heating value, bamboo is a promising energy crop for the future. The aim of this study was to evaluate the effects of torrefaction on the main energy properties of Bambusa vulgaris. Three different torrefaction temperatures were employed: 220, 250 and 280°C. The elemental characteristics of lignite and coal were compared to the torrefied bamboo. The characteristics of the biomass fuels tend toward those of low rank coals. Principal component analysis of FTIR data showed a clear separation between the samples by thermal treatment. The loadings plot indicated that the bamboo samples underwent chemical changes related to carbonyl groups, mostly present in hemicelluloses, and to aromatic groups present in lignin. PMID:21703854

  5. Oxygen carriers for chemical looping combustion of solid fuels

    Microsoft Academic Search

    Aurora Rubel; Kunlei Liu; Jim Neathery; Darrell Taulbee

    2009-01-01

    A thermal analyzer–differential scanning calorimeter–mass spectrometer (TG–DSC–MS) was used to study oxygen carriers (OC) for their potential use for the application of chemical looping combustion (CLC) to solid fuels. Reaction rates, changes in reaction rates with repeated oxidation–reductions, exothermic heats during oxidation, and the effect of changing reduction gas compositions were studied. Oxidation rates were greater than reduction rates and

  6. The NASA broad-specification fuels combustion technology program: An assessment of phase 1 test results

    NASA Technical Reports Server (NTRS)

    Fear, J. S.

    1983-01-01

    An assessment is made of the results of Phase 1 screening testing of current and advanced combustion system concepts using several broadened-properties fuels. The severity of each of several fuels-properties effects on combustor performance or liner life is discussed, as well as design techniques with the potential to offset these adverse effects. The selection of concepts to be pursued in Phase 2 refinement testing is described. This selection takes into account the relative costs and complexities of the concepts, the current outlook on pollutant emissions control, and practical operational problems.

  7. Plasma-Enhanced Combustion of Hydrocarbon Fuels and Fuel Blends Using Nanosecond Pulsed Discharges

    SciTech Connect

    Cappelli, Mark; Mungal, M Godfrey

    2014-10-28

    This project had as its goals the study of fundamental physical and chemical processes relevant to the sustained premixed and non-premixed jet ignition/combustion of low grade fuels or fuels under adverse flow conditions using non-equilibrium pulsed nanosecond discharges.

  8. FUNDAMENTAL INVESTIGATION OF FUEL TRANSFORMATIONS IN PULVERIZED COAL COMBUSTION AND GASIFICATION TECHNOLOGIES

    SciTech Connect

    Robert Hurt; Joseph Calo; Thomas H. Fletcher; Alan Sayre

    2005-04-29

    The goal of this project was to carry out the necessary experiments and analyses to extend current capabilities for modeling fuel transformations to the new conditions anticipated in next-generation coal-based, fuel-flexible combustion and gasification processes. This multi-organization, multi-investigator project has produced data, correlations, and submodels that extend present capabilities in pressure, temperature, and fuel type. The combined experimental and theoretical/computational results are documented in detail in Chapters 1-8 of this report, with Chapter 9 serving as a brief summary of the main conclusions. Chapters 1-3 deal with the effect of elevated pressure on devolatilization, char formation, and char properties. Chapters 4 and 5 deal with advanced combustion kinetic models needed to cover the extended ranges of pressure and temperature expected in next-generation furnaces. Chapter 6 deals with the extension of kinetic data to a variety of alternative solid fuels. Chapter 7 focuses on the kinetics of gasification (rather than combustion) at elevated pressure. Finally, Chapter 8 describes the integration, testing, and use of new fuel transformation submodels into a comprehensive CFD framework. Overall, the effects of elevated pressure, temperature, heating rate, and alternative fuel use are all complex and much more work could be further undertaken in this area. Nevertheless, the current project with its new data, correlations, and computer models provides a much improved basis for model-based design of next generation systems operating under these new conditions.

  9. Fireside Corrosion in Oxy-fuel Combustion of Coal

    SciTech Connect

    G. R. Holcomb; J. Tylczak; G. H. Meier; B. Lutz; K. Jung; N. Mu; N. M. Yanar; F. S. Pettit; J. Zhu; A. Wise; D. Laughlin; S. Sridhar

    2012-05-20

    Oxy-fuel combustion is burning a fuel in oxygen rather than air. The low nitrogen flue gas that results is relatively easy to capture CO{sub 2} from for reuse or sequestration. Corrosion issues associated with the environment change (replacement of much of the N{sub 2} with CO{sub 2} and higher sulfur levels) from air- to oxy-firing were examined. Alloys studied included model Fe-Cr alloys and commercial ferritic steels, austenitic steels, and nickel base superalloys. The corrosion behavior is described in terms of corrosion rates, scale morphologies, and scale/ash interactions for the different environmental conditions.

  10. Fuel properties of cottonseed oil

    SciTech Connect

    Karaosmanoglu, F.; Tueter, M.; Goellue, E. [Istanbul Technical Univ. (Turkey). Dept. of Chemical Engineering; Yanmaz, S.; Altintig, E. [Sakarya Univ. (Turkey). Dept. of Chemistry

    1999-11-01

    The use of vegetable oils as fuel alternatives has an exceptional importance in the field of research. In this study, evaluation possibilities of cottonseed oil have been investigated as an alternative candidate for diesel fuel and fuel oil. The fuel property tests were performed according to standard analysis methods for oil and fuel. An overall evaluation of the results indicates that cottonseed oil can be proposed as a possible green substitute for fuel.

  11. High sensitivity of diesel soot morphological and optical properties to combustion temperature in a shock tube.

    PubMed

    Qiu, Chong; Khalizov, Alexei F; Hogan, Brian; Petersen, Eric L; Zhang, Renyi

    2014-06-01

    Carbonaceous particles produced from combustion of fossil fuels have strong impacts on air quality and climate, yet quantitative relationships between particle characteristics and combustion conditions remain inadequately understood. We have used a shock tube to study the formation and properties of diesel combustion soot, including particle size distributions, effective density, elemental carbon (EC) mass fraction, mass-mobility scaling exponent, hygroscopicity, and light absorption and scattering. These properties are found to be strongly dependent on the combustion temperature and fuel equivalence ratio. Whereas combustion at higher temperatures (?2000 K) yields fractal particles of a larger size and high EC content (90 wt %), at lower temperatures (?1400 K) smaller particles of a higher organic content (up to 65 wt %) are produced. Single scattering albedo of soot particles depends largely on their organic content, increasing drastically from 0.3 to 0.8 when the particle EC mass fraction decreases from 0.9 to 0.3. The mass absorption cross-section of diesel soot increases with combustion temperature, being the highest for particles with a higher EC content. Our results reveal that combustion conditions, especially the temperature, may have significant impacts on the direct and indirect climate forcing of atmospheric soot aerosols. PMID:24803287

  12. Kinetics of pyrolysis, combustion and gasification of three biomass fuels

    Microsoft Academic Search

    Osvalda Senneca

    2007-01-01

    The paper compares the microstructural properties and the intrinsic reactivity of pine seed shells, olive husk and wood chips upon pyrolysis, combustion and gasification (with CO2 and H2O). Such biomasses, all of interest in energy production, are quite different from one another in terms of O\\/C and H\\/C content, of porosimetric structure and of ash content.An extensive campaign of isothermal

  13. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices and flares.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...calibration drift tests. (vi) Fuel gas combustion devices having...an affected facility subject to...calibration drift tests. (6...equipped with combustion modification-based...for fuel gas combustion devices...performance test....

  14. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices and flares.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...calibration drift tests. (vi) Fuel gas combustion devices having...an affected facility subject to...calibration drift tests. (6...equipped with combustion modification-based...for fuel gas combustion devices...performance test....

  15. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...total sulfur content of the turbine's combustion fuel? 60.4360 Section 60.4360...Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360...total sulfur content of the turbine's combustion fuel? You must monitor the...

  16. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...total sulfur content of the turbine's combustion fuel? 60.4360 Section 60.4360...Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360...total sulfur content of the turbine's combustion fuel? You must monitor the...

  17. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...total sulfur content of the turbine's combustion fuel? 60.4360 Section 60.4360...Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360...total sulfur content of the turbine's combustion fuel? You must monitor the...

  18. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...total sulfur content of the turbine's combustion fuel? 60.4360 Section 60.4360...Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360...total sulfur content of the turbine's combustion fuel? You must monitor the...

  19. 40 CFR 60.4360 - How do I determine the total sulfur content of the turbine's combustion fuel?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...total sulfur content of the turbine's combustion fuel? 60.4360 Section 60.4360...Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360...total sulfur content of the turbine's combustion fuel? You must monitor the...

  20. Combustion Simulation Databases for Real Transportation Fuels: A New Community Collaboration

    E-print Network

    Magee, Joseph W.

    Combustion Simulation Databases for Real Transportation Fuels: A New Community Collaboration T. C, and health benefits that could be derived from improved combustion processes are enormous and well recognized on Combustion Simulation Databases for Real Transportation Fuels to assess needs and opportunities to translate

  1. Paper Number 15736-PA Title Reaction Kinetics of Fuel Formation for In-Situ Combustion

    E-print Network

    Abu-Khamsin, Sidqi

    Paper Number 15736-PA Title Reaction Kinetics of Fuel Formation for In-Situ Combustion Authors Abu believed to cause fuel formation for in-situ combustion have been studied and modeled. A thin, packed bed the approach of a combustion front. Analysis of gases produced from the reaction cell revealed that pyrolysis

  2. Ignition and Combustion of Fuel Pockets Moving in an Oxidizing Atmosphere

    E-print Network

    Heil, Matthias

    Ignition and Combustion of Fuel Pockets Moving in an Oxidizing Atmosphere JOEL DAOU Dpto, Spain. E-mail: daou@tupi.dmt.upm.es Ignition and combustion of an initially spherical pocket of fuel, the results provide a good appreciation of the dynamics of the combustion process. For example, it is found

  3. Combustion

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    The process whereby a substance is combined with oxygen with the production of heat. Burning is a familiar example of this process. The energy required to propel chemical rockets is provided by the combustion of fuel with an oxidant at very high temperatures. A common oxidant is liquid oxygen (often denoted by LOX). Others include hydrogen peroxide and nitrogen tetroxide....

  4. Construction of combustion models for rapeseed methyl ester bio-diesel fuel for internal combustion engine applications

    Microsoft Academic Search

    Valeri I. Golovitchev; Junfeng Yang

    2009-01-01

    Bio-diesel fuels are non-petroleum-based diesel fuels consisting of long chain alkyl esters produced by the transesterification of vegetable oils, that are intended for use (neat or blended with conventional fuels) in unmodified diesel engines. There have been few reports of studies proposing theoretical models for bio-diesel combustion simulations. In this study, we developed combustion models based on ones developed previously.

  5. Energy release properties of amorphous boron and boron-based propellant primary combustion products

    NASA Astrophysics Data System (ADS)

    Liang, Daolun; Liu, Jianzhong; Xiao, Jinwu; Xi, Jianfei; Wang, Yang; Zhang, Yanwei; Zhou, Junhu

    2015-07-01

    The microstructure of amorphous boron and the primary combustion products of boron-based fuel-rich propellant (hereafter referred to as primary combustion products) was analyzed by scanning electron microscope. Composition analysis of the primary combustion products was carried out by X-ray diffraction and X-ray photoelectron spectroscopy. The energy release properties of amorphous boron and the primary combustion products were comparatively studied by laser ignition experimental system and thermogravimetry-differential scanning calorimetry. The primary combustion products contain B, C, Mg, Al, B4C, B13C2, BN, B2O3, NH4Cl, H2O, and so on. The energy release properties of primary combustion products are different from amorphous boron, significantly. The full-time spectral intensity of primary combustion products at a wavelength of 580 nm is ~2% lower than that of amorphous boron. The maximum spectral intensity of the former at full wave is ~5% higher than that of the latter. The ignition delay time of primary combustion products is ~150 ms shorter than that of amorphous boron, and the self-sustaining combustion time of the former is ~200 ms longer than that of the latter. The thermal oxidation process of amorphous boron involves water evaporation (weight loss) and boron oxidation (weight gain). The thermal oxidation process of primary combustion products involves two additional steps: NH4Cl decomposition (weight loss) and carbon oxidation (weight loss). CL-20 shows better combustion-supporting effect than KClO4 in both the laser ignition experiments and the thermal oxidation experiments.

  6. Evaluating Fuel-Air Mixing in a Direct-Injection Hydrogen-Fueled Internal Combustion Engine

    NASA Astrophysics Data System (ADS)

    Ebadi, Alireza; White, Christopher

    2012-11-01

    Proper orthogonal decomposition (POD) is used to decompose in-cylinder particle image velocimetry (PIV) vector fields acquired in a direct injection hydrogen-fueled internal combustion engine (DI-H2ICE) into mean, coherent, and incoherent vector fields, where the coherent vector fields are presumed to capture the cycle-variability of the flow. The POD vector fields are then used to investigate the effects of fuel injection timing on in-cylinder turbulence and fuel-air mixing.

  7. Emission reduction potential from the combustion of soy methyl ester fuel blended with petroleum distillate fuel

    Microsoft Academic Search

    S. Win Lee; T. Herage; B. Young

    2004-01-01

    Combustion performance of a blend containing 20% soybean methyl ester in heating No. 2 fuel was examined using a residential-scale hot water boiler. The blend burned satisfactorily with no modifications to the appliance and fuel delivery system. SO2 emissions were 19.7±2.5% lower than that of No. 2 fuel while NOx emissions were similar. Particulate emissions, as determined by a source

  8. NASA Broad Specification Fuels Combustion Technology program - Pratt and Whitney Aircraft Phase I results and status

    NASA Technical Reports Server (NTRS)

    Lohmann, R. P.; Fear, J. S.

    1982-01-01

    In connection with increases in the cost of fuels and the reduced availability of high quality petroleum crude, a modification of fuel specifications has been considered to allow acceptance of poorer quality fuels. To obtain the information upon which a selection of appropriate fuels for aircraft can be based, the Broad Specification Fuels Combustion Technology program was formulated by NASA. A description is presented of program-related investigations conducted by an American aerospace company. The specific objective of Phase I of this program has been to evaluate the impact of the use of broadened properties fuels on combustor design through comprehensive combustor rig testing. Attention is given to combustor concepts, experimental evaluation, results obtained with single stage combustors, the stage combustor concept, and the capability of a variable geometry combustor.

  9. Combustion

    NASA Technical Reports Server (NTRS)

    Bulzan, Dan

    2007-01-01

    An overview of the emissions related research being conducted as part of the Fundamental Aeronautics Subsonics Fixed Wing Project is presented. The overview includes project metrics, milestones, and descriptions of major research areas. The overview also includes information on some of the emissions research being conducted under NASA Research Announcements. Objective: Development of comprehensive detailed and reduced kinetic mechanisms of jet fuels for chemically-reacting flow modeling. Scientific Challenges: 1) Developing experimental facilities capable of handling higher hydrocarbons and providing benchmark combustion data. 2) Determining and understanding ignition and combustion characteristics, such as laminar flame speeds, extinction stretch rates, and autoignition delays, of jet fuels and hydrocarbons relevant to jet surrogates. 3) Developing comprehensive kinetic models for jet fuels.

  10. Experimental results with hydrogen fueled internal combustion engines

    NASA Technical Reports Server (NTRS)

    De Boer, P. C. T.; Mclean, W. J.; Homan, H. S.

    1975-01-01

    The paper focuses on the most important experimental findings for hydrogen-fueled internal combustion engines, with particular reference to the application of these findings to the assessment of the potential of hydrogen engines. Emphasis is on the various tradeoffs that can be made, such as between maximum efficiency, maximum power, and minimum NO emissions. The various possibilities for induction and ignition are described. Some projections are made about areas in which hydrogen engines may find their initial application and about optimum ways to design such engines. It is shown that hydrogen-fueled reciprocal internal combustion engines offer important advantages with respect to thermal efficiency and exhaust emissions. Problems arising from preignition can suitably be avoided by restricting the fuel-air equivalence ratio to values below about 0.5. The direct cylinder injection appears to be a very attractive way to operate the engine, because it combines a wide range of possible power outputs with a high thermal efficiency and very low NO emissions at part loads.

  11. Interaction of counterpropagating hot spots in solid fuel combustion

    NASA Astrophysics Data System (ADS)

    Bayliss, A.; Matkowsky, B. J.

    1999-04-01

    We consider a model of gasless solid fuel combustion of a cylindrical sample, which describes the SHS (self-propagating high temperature synthesis) process for the synthesis of advanced materials. In this process a compacted powder sample of reactants is ignited at one end and a combustion wave then propagates along the cylindrical axis of the sample converting the unreacted powder to the desired product material. To simplify the presentation we assume that combustion occurs only on the surface of the cylinder, and thus consider the resulting two-dimensional problem. It is known, both experimentally and theoretically, that there exist spinning modes of propagation, i.e., nonaxisymmetric solutions characterized by the formation of hot spots (localized high temperature pulses) which rotate around the sample as they propagate, thus following a helical path on the cylinder. We compute solutions involving counterpropagating hot spots. When the spots collide, we show that they undergo one of three possible interactions: (i) a strong (hot) spot collides with a weak (cooler) spot with both the strong and weak spots continuing to rotate in the same direction as before the interaction, (ii) two strong spots collide to produce two weak spots, and (iii) two weak spots collide to produce two strong spots. The latter two interactions describe the phenomena of apparent annihilation and creation of hot spots, respectively, which have been recently observed in experiments.

  12. Combustion characteristics in the transition region of liquid fuel sprays

    NASA Technical Reports Server (NTRS)

    Cernansky, N. P.; Namer, I.; Tidona, R. J.

    1986-01-01

    A number of important effects have been observed in the droplet size transition region in spray combustion systems. In this region, where the mechanism of flame propagation is transformed from diffusive to premixed dominated combustion, the following effects have been observed: (1) maxima in burning velocity; (2) extension of flammability limits; (3) minima in ignition energy; and (4) minima in NOx formation. A monodisperse aerosol generator has been used to form and deliver a well controlled liquid fuel spray to the combustion test section where measurements of ignition energy have been made. The ignition studies were performed on monodisperse n-heptane sprays at atmospheric pressure over a range of equivalence ratios and droplet diameters. A capacitive discharge spark ignition system was used as the ignition source, providing independent control of spark energy and duration. Preliminary measurements were made to optimize spark duration and spark gap, optimum conditions being those at which the maximum frequency or probability of ignition was observed. Using the optimum electrode spacing and spark duration, the frequency of ignition was determined as a function of spark energy for three overall equivalence ratios (0.6, 0.8, and 1.0) and for initial droplet diameters of 25, 40, 50, 60, and 70 micro m.

  13. High pressure combustion of liquid fuels. [alcohol and n-paraffin fuels

    NASA Technical Reports Server (NTRS)

    Canada, G. S.

    1974-01-01

    Measurements were made of the burning rates and liquid surface temperatures for a number of alcohol and n-paraffin fuels under natural and forced convection conditions. Porous spheres ranging in size from 0.64-1.9 cm O.D. were emloyed to simulate the fuel droplets. The natural convection cold gas tests considered the combustion in air of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane droplets at pressures up to 78 atmospheres. The pressure levels of the natural convection tests were high enough so that near critical combustion was observed for methanol and ethanol vaporization rates and liquid surface temperature measurements were made of droplets burning in a simulated combustion chamber environment. Ambient oxygen molar concentrations included 13%, 9.5% and pure evaporation. Fuels used in the forced convection atmospheric tests included those listed above for the natural convection tests. The ambient gas temperature ranged from 600 to 1500 K and the Reynolds number varied from 30 to 300. The high pressure forced convection tests employed ethanol and n-heptane as fuels over a pressure range of one to 40 atmospheres. The ambient gas temperature was 1145 K for the two combustion cases and 1255 K for the evaporation case.

  14. Fuel supply control method for internal combustion engines at fuel cut operation

    Microsoft Academic Search

    Hasegawa

    1986-01-01

    A method is described for electronically controlling the quantity of fuel being supplied through injection to an internal combustion engine in synchronism with generation of pulses of a predetermined control signal, in response to operating conditions of the engine. The engine has an exhaust passage and a catalyst device arranged in the exhaust passage for purifying exhaust gases. The method

  15. Spiking of Hydrocarbon Fuels with Silanes-based Combustion Enhancers

    NASA Astrophysics Data System (ADS)

    Hidding, Bernhard; Fikri, Mustapha; Bozkurt, Metehan; Schulz, Christof; Soltner, Theresa; Kornath, Andreas; Pfitzner, Michael; Lang, Martin; Adamczyk, Andrew J.; Broadbelt, Linda; Ellerbrock, Hartwig; Simone, Domenico; Bruno, Claudio

    The concept of spiking hydrocarbon fuels such as kerosenes with liquid silicon hydrides in order to render the fuel combination hypergolic and to improve the combustion efficiency is presented and preliminarily analyzed. In view of scarcity of available data, various approaches are used, among them quantum-mechanical ab initio calculations for the thermodynamics and shock-tube measurements for the kinetics of higher, liquid silanes. Based on these results and other data, performance predictions indicate that miscible hydrocarbon/silicon hydride fuels (HC/SH) have the potential to be stored in a single tank, to be hypergolic with many oxidizers, and to yield similar, partly better specific impulses (and volume-specific impulses) than hydrocarbon fuels without silane additives. A variety of hybrid HC/SH fuel combinations seems to be accessible, which might offer the possibility to design a fuel combination with characteristics adjustable in a wide range. The current and future availability of larger amounts of liquid silanes is discussed.

  16. Organic aerosol emission ratios from the laboratory combustion of biomass fuels

    NASA Astrophysics Data System (ADS)

    Jolleys, Matthew D.; Coe, Hugh; McFiggans, Gordon; McMeeking, Gavin R.; Lee, Taehyoung; Kreidenweis, Sonia M.; Collett, Jeffrey L.; Sullivan, Amy P.

    2014-11-01

    Organic aerosol (OA) emission ratios (ER) have been characterized for 67 burns during the second Fire Laboratory at Missoula Experiment. These fires involved 19 different species representing 6 major fuels, each of which forms an important contribution to the U.S. biomass burning inventory. Average normalized ?OA/?CO ratios show a high degree of variability, both between and within different fuel types and species, typically exceeding differen-ces between separate plumes in ambient measurements. This variability is strongly influenced by highly contrasting ?OA levels between burns and the increased partitioning of semivolatile organic compounds to the particle phase at high ?OA concentrations. No correlation across all fires was observed between ?OA/?CO and modified combustion efficiency (MCE), which acts as an indicator of the proportional contributions of flaming and smoldering combustion phases throughout each burn. However, a negative correlation exists with MCE for some coniferous species, most notably Douglas fir, for which there is also an influence from fuel moisture content. Changes in fire efficiency were also shown to dramatically alter emissions for fires with very similar initial conditions. Although the relationship with MCE is variable between species, there is greater consistency with the level of oxygenation in OA. The ratio of the m/z 44 fragment to total OA mass concentration (f44) as measured by aerosol mass spectrometer provides an indication of oxygenation as influenced by combustion processes at source, with ?OA/?CO decreasing with increasing f44 for all fuel types. Inconsistencies in the magnitude of the effects associated with each potential influence on ?OA/?CO emphasize the lack of a single dominant control on fire emissions, and a dependency on both fuel properties and combustion conditions.

  17. On-Line Measurement of Heat of Combustion of Gaseous Hydrocarbon Fuel Mixtures

    NASA Technical Reports Server (NTRS)

    Sprinkle, Danny R.; Chaturvedi, Sushil K.; Kheireddine, Ali

    1996-01-01

    A method for the on-line measurement of the heat of combustion of gaseous hydrocarbon fuel mixtures has been developed and tested. The method involves combustion of a test gas with a measured quantity of air to achieve a preset concentration of oxygen in the combustion products. This method involves using a controller which maintains the fuel (gas) volumetric flow rate at a level consistent with the desired oxygen concentration in the combustion products. The heat of combustion is determined form a known correlation with the fuel flow rate. An on-line computer accesses the fuel flow data and displays the heat of combustion measurement at desired time intervals. This technique appears to be especially applicable for measuring heats of combustion of hydrocarbon mixtures of unknown composition such as natural gas.

  18. FUEL FORMULATION EFFECTS ON DIESEL FUEL INJECTION, COMBUSTION, EMISSIONS AND EMISSION CONTROL

    SciTech Connect

    Boehman, A; Alam, M; Song, J; Acharya, R; Szybist, J; Zello, V; Miller, K

    2003-08-24

    This paper describes work under a U.S. DOE sponsored Ultra Clean Fuels project entitled ''Ultra Clean Fuels from Natural Gas,'' Cooperative Agreement No. DE-FC26-01NT41098. In this study we have examined the incremental benefits of moving from low sulfur diesel fuel and ultra low sulfur diesel fuel to an ultra clean fuel, Fischer-Tropsch diesel fuel produced from natural gas. Blending with biodiesel, B100, was also considered. The impact of fuel formulation on fuel injection timing, bulk modulus of compressibility, in-cylinder combustion processes, gaseous and particulate emissions, DPF regeneration temperature and urea-SCR NOx control has been examined. The primary test engine is a 5.9L Cummins ISB, which has been instrumented for in-cylinder combustion analysis and in-cylinder visualization with an engine videoscope. A single-cylinder engine has also been used to examine in detail the impacts of fuel formulation on injection timing in a pump-line-nozzle fueling system, to assist in the interpretation of results from the ISB engine.

  19. Combustion of liquid fuel droplets in supercritical conditions

    NASA Technical Reports Server (NTRS)

    Shuen, J. S.; Yang, Vigor

    1991-01-01

    A comprehensive analysis of liquid-fuel droplet combustion in both sub- and super-critical environments has been conducted. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates finite-rate chemical kinetics and a full treatment of liquid-vapor phase equilibrium at the droplet surface. The governing equations and the associated interface boundary conditions are solved numerically using a fully coupled, implicit scheme with the dual time-stepping integration technique. The model is capable of treating the entire droplet history, including the transition from the subcritical to the supercritical state. As a specific example, the combustion of n-pentane fuel droplets in air is studied for pressures of 5-140 atm. Results indicate that the ambient gas pressure exerts significant control of droplet gasification and burning processes through its influences on the fluid transport, gas/liquid interface thermodynamics, and chemical reactions. The droplet gasification rate increases progressively with pressure. However, the data for the overall burnout time exhibits a significant variation near the critical burning pressure, mainly as a result of reduced mass-diffusion rate and latent heat of vaporization with increased pressure. The influence of droplet size on the burning characteristics is also noted.

  20. Mach 2 combustion characteristics of hydrogen/hydrocarbon fuel mixtures

    SciTech Connect

    Diskin, G.S.; Jachimowski, C.J.; Northam, G.B.; Bell, R.A.

    1987-01-01

    The combustion of H/sub 2//CH/sub 4/ and H/sub 2//C/sub 2/H/sub 4/ mixtures containing 10 to 70 vol pct hydrocarbon at combustor inlet Mach number 2 and temperatures 2000 to 4000 R is investigated experimentally, applying direct-connect test hardware and techniques similar to those described by Diskin and Northam (1987) in the facilities of the NASA Langley Hypersonic Propulsion Branch. The experimental setup, procedures, and data-reduction methods are described; and the results are presented in extensive tables and graphs and characterized in detail. Fuel type and mixture are found to have little effect on the wall heating rate measured near the combustor exit, but H/sub 2//C/sub 2/H/sub 4/ is shown to burn much more efficiently than H/sub 2//CH/sub 4/, with no pilot-off blowout equivalence ratios greater than 0.5. It is suggested that H/sub 2//hydrocarbon mixtures are feasible fuels (at least in terms of combustion efficiency) for scramjet SSTO vehicles operating at freestream Mach numbers above 4.

  1. Device at combustion plants for automatic feeding of fuels within the furnace of the plant

    Microsoft Academic Search

    Lovgren

    1986-01-01

    A method is described for feeding solid fuel through a furnace of a combustion plant, comprising the steps of: positioning solid fuel on a fuel-receiving end of movable grate means, advancing the movable grate means through the furnace from the fuel-receiving end to a fuel-discharging end of the grate means, while combusting the fuel disposed thereon. The grate means is

  2. Fireside Corrosion in Oxy-fuel Combustion of Coal

    SciTech Connect

    Holcomb, Gordon R [National Energy Technology Laboratory; Tylczak, Joseph [National Energy Technology Laboratory; Meier, Gerald H [University of Pittsburgh; Lutz, Bradley [University of Pittsburgh; Jung, Keeyoung [Institute of Industrial Science and Technology, Korea; Mu, Nan; Yanar, Nazik M [University of Pittsburgh; Pettit, Frederick S [University of Pittsburgh; Zhu, Jingxi [Carnegie Mellon University; Wise, Adam [Carnegie Mellon University; Laughlin, David E. [Carnegie Mellon University; Sridhar, Seetharaman [Carnegie Mellon University

    2013-11-25

    Oxy-fuel combustion is burning a fuel in oxygen rather than air for ease of capture of CO2 from for reuse or sequestration. Corrosion issues associated with the environment change (replacement of much of the N2 with CO2 and higher sulfur levels) from air- to oxy-firing were examined. Alloys studied included model Fe–Cr alloys and commercial ferritic steels, austenitic steels, and nickel base superalloys. The corrosion behavior is described in terms of corrosion rates, scale morphologies, and scale/ash interactions for the different environmental conditions. Evidence was found for a hreshold for severe attack between 10-4 and 10-3 atm of SO3 at 700şC.

  3. A novel gas turbine cycle with hydrogen-fueled chemical-looping combustion

    Microsoft Academic Search

    Hongguang Jin; Masaru Ishida

    2000-01-01

    In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H2\\/O2 combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle

  4. Analysis of Fuel Vaporization, Fuel-Air Mixing, and Combustion in Integrated Mixer-Flame Holders

    NASA Technical Reports Server (NTRS)

    Deur, J. M.; Cline, M. C.

    2004-01-01

    Requirements to limit pollutant emissions from the gas turbine engines for the future High-Speed Civil Transport (HSCT) have led to consideration of various low-emission combustor concepts. One such concept is the Integrated Mixer-Flame Holder (IMFH). This report describes a series of IMFH analyses performed with KIVA-II, a multi-dimensional CFD code for problems involving sprays, turbulence, and combustion. To meet the needs of this study, KIVA-II's boundary condition and chemistry treatments are modified. The study itself examines the relationships between fuel vaporization, fuel-air mixing, and combustion. Parameters being considered include: mixer tube diameter, mixer tube length, mixer tube geometry (converging-diverging versus straight walls), air inlet velocity, air inlet swirl angle, secondary air injection (dilution holes), fuel injection velocity, fuel injection angle, number of fuel injection ports, fuel spray cone angle, and fuel droplet size. Cases are run with and without combustion to examine the variations in fuel-air mixing and potential for flashback due to the above parameters. The degree of fuel-air mixing is judged by comparing average, minimum, and maximum fuel/air ratios at the exit of the mixer tube, while flame stability is monitored by following the location of the flame front as the solution progresses from ignition to steady state. Results indicate that fuel-air mixing can be enhanced by a variety of means, the best being a combination of air inlet swirl and a converging-diverging mixer tube geometry. With the IMFH configuration utilized in the present study, flashback becomes more common as the mixer tube diameter is increased and is instigated by disturbances associated with the dilution hole flow.

  5. Optimization of burning process of hydrocarbon fuels with varying specific heat of combustion

    NASA Astrophysics Data System (ADS)

    Saifullin, E. R.; Vankov, Yu V.

    2015-06-01

    This article explores the combustion of gaseous fuel in the case of an abrupt change of the specific heat of combustion. Analyzes the changes in the rate of heat when the fuel and air flows are constant. Defines the conditions for which retained the initial rate of heat release and optimal fuel-air ratio.

  6. DOE Project 18546, AOP Task 1.1, Fuel Effects on Advanced Combustion Engines

    Microsoft Academic Search

    Bruce G Bunting; Michael Bunce

    2012-01-01

    Research in 2011 was focused on diesel range fuels and diesel combustion and fuels evaluated in 2011 included a series of oxygenated biofuels fuels from University of Maine, oxygenated fuel compounds representing materials which could be made from sewage, oxygenated marine diesel fuels for low emissions, and a new series of FACE fuel surrogates and FACE fuels with detailed exhaust

  7. The history of mercury emissions from fuel combustion in Maritime Canada

    E-print Network

    Sunderland, Elsie M.

    The history of mercury emissions from fuel combustion in Maritime Canada E.M. Sunderlanda, *, G ``Capsule'': An inventory of historical emissions of mercury from combustion in maritime Canada is presented combustion of wood, coal and re®ned petroleum products in Maritime Canada. The pattern of emissions

  8. Fine Particle Emissions from Heavy Fuel Oil Combustion in a Firetube Package Boiler

    Microsoft Academic Search

    C. A. Miller; W. P. Linak; C. King; J. O. L. Wendt

    1998-01-01

    Combustion is a significant source of fine particulate matter (PM) emissions, and heavy oil combustion is suspected of producing particulate emissions with potentially significant toxicity. This paper is concerned with the characterization of particulate emissions from a practical boiler burning heavy fuel oils, The purpose of the study was to identify possible mechanisms that might relate both the combustion process

  9. Control-relevant Modelling and Linear Analysis of Instabilities in Oxy-fuel Combustion

    E-print Network

    Foss, Bjarne A.

    Control-relevant Modelling and Linear Analysis of Instabilities in Oxy-fuel Combustion Dagfinn combustion have been proposed as an alternative to conventional gas turbine cycles for achieving CO2-capture for CO2 sequestration purposes. While combustion instabilities is a problem in modern conventional gas

  10. NASA/General Electric broad-specification fuels combustion technology program

    NASA Technical Reports Server (NTRS)

    Dodds, W. J.

    1984-01-01

    The NASA/General Electric Broad Specification Fuels Combustion Technology Program is being conducted to evolve and demonstrate the technology required to use broadened-properties fuels in current and next generation commercial aircraft engines. The first phase of this program, completed in 1982, involved the design and test evaluation of three different combustor concepts. All combustors were designed for the General Electric CF6-80A engine envelope and operating conditions, using Experimental Referee Broad Specification (ERBS) fuel having a fuel hydrogen content of 12.8% by weight. Several different configurations of each combustor concept were evaluated in a series of high pressure sector combustor component tests. A total of 25 sector tests were conducted during phase 1. Combustor metal temperatures, emissions, exit temperature profiles, and radiant heat flux were measured over the full range of steady-state operating conditions using four fuels having nominal hydrogen contents between 11.8 and 14%. During the current phase 2 program, the two most promising concepts from phase 1 are being further refined and evaluated. For phase 2 testing, two additional fuels representing a wider range of fluidity and volatility are also being used in combustion system tests.

  11. Explosively Driven Combustion of Shock-Dispersed Fuels

    NASA Astrophysics Data System (ADS)

    Neuwald, Peter

    2005-07-01

    Since the eighties our working group has been studying classical blast effects in small-scale experiments using custom-made miniature charges of 0.2 g to 1.5 g PETN. However, in the recent years the interest has shifted towards the performance of non-ideal explosives and the importance of secondary reactions such as after-burning. Thus we have designed an additional charge type, called Shock-Dispersed Fuel (SDF) charge. It consists of a lightweight, small paper cylinder filled with about one gram of a flammable powder (e.g., flake aluminum) surrounding a spherical PETN booster of 0.5 g. We have tested the SDF charges in a number of different environments, realized as closed steel vessels of simple geometry (barometric bombs). Three of the bombs vary in volume (6.6 l, 21.2 l and 40.5 l), while their aspect ratio L/D is kept constant at about 1. Two further bombs are comparable to the smallest bomb in volume (6.3 l), but provide different aspect ratios: L/D = 4.6 and 12.5. In addition, we have also performed tests in a tunnel-model with an L/D = 37.5. Our basic goal is to assess the performance of the charges by means of the combustion-related pressure built-up. Thus we contrast experiments on SDF charges in air with tests in nitrogen, to inhibit combustion, and with tests on conventional charges. Experiments and theoretical estimates on the expected overpressure allow one to formulate various indicators for the observed combustion performance. For SDF charges these indicate that the combustion efficiency decreases not only with increasing volume of the barometric bomb, but also with increasing aspect ratio at constant volume. This bears importance to the performance of SDF charges in tunnel environments. The performance losses reflect -- at least in part -- geometry-specific constraints on the mixing between fuel and air.

  12. Predicting various biodiesel fuel properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several essential fuel properties of biodiesel are largely determined by the properties of the fatty esters which are its main components. These include cetane number, kinematic viscosity, oxidative stability, and cold flow which are contained in almost all biodiesel standards but also other propert...

  13. Cycle-to-Cycle Fluctuations of Burned Fuel Mass in Spark Ignition Combustion Engines

    E-print Network

    M. Wendeker; G. Litak; M. Krupa

    2003-12-28

    We examine a simple, fuel-air, model of combustion in spark ignition (si) engine with indirect injection. In our two fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process strongly depending on the quality of air-fulel mixture. The largest influence was found in the limit of a lean combustion. The possible effect of nonlinearities in the combustion process were also discussed.

  14. Functionalized graphene sheet colloids for enhanced fuel/propellant combustion.

    PubMed

    Sabourin, Justin L; Dabbs, Daniel M; Yetter, Richard A; Dryer, Frederick L; Aksay, Ilhan A

    2009-12-22

    We have compared the combustion of the monopropellant nitromethane with that of nitromethane containing colloidal particles of functionalized graphene sheets or metal hydroxides. The linear steady-state burning rates of the monopropellant and colloidal suspensions were determined at room temperature, under a range of pressures (3.35-14.4 MPa) using argon as a pressurizing fluid. The ignition temperatures were lowered and burning rates increased for the colloidal suspensions compared to those of the liquid monopropellant alone, with the graphene sheet suspension having significantly greater burning rates (i.e., greater than 175%). The relative change in burning rate from neat nitromethane increased with increasing concentrations of fuel additives and decreased with increasing pressure until at high pressures no enhancement was found. PMID:19925013

  15. Determination of alternative fuels combustion products: Phase 2 final report

    SciTech Connect

    Whitney, K.A.

    1997-06-01

    This report describes the laboratory efforts to accomplish four independent tasks: (1) speciation of hydrocarbon exhaust emissions from a light-duty vehicle operated over the chassis dynamometer portion of the light-duty FTP after modifications for operation on butane and butane blends; (2) evaluation of NREL`s Variable Conductance Vacuum Insulated Catalytic Converter Test Article 4 for the reduction of cold-start FTP exhaust emissions after extended soak periods for a Ford FFV Taurus operating on E85; (3) support of UDRI in an attempt to define correlations between engine-out combustion products identified by SwRI during chassis dynamometer testing, and those found during flow tube reactor experiments conducted by UDRI; and (4) characterization of small-diameter particulate matter from a Ford Taurus FFV operating in a simulated fuel-rich failure mode on CNG, LPG, M85, E85, and reformulated gasoline. 22 refs., 18 figs., 17 tabs.

  16. Corrosion of experimental superheater alloys in waste fuel combustion

    SciTech Connect

    Nyloef, L. [AB Sandvik Steel, Sandviken (Sweden); Haeggblom, E. [Studsvik Material AB, Nykoeping (Sweden)

    1997-08-01

    A number of experimental nickel base alloys have been evaluated regarding their resistance against high temperature corrosion in waste fuel combustion. Specimens were produced by hot extrusion of 50 kg ingots and exposed at 450 C and 490 C on cooled testing probes in the superheater section of a municipal solid waste (MSW) incineration plant. The effect on corrosion by different chromium, molybdenum and niobium concentrations were studied in terms of wall thickness reduction during test periods of up to 2,160 hours. Comparison was made with reference materials such as low alloyed pressure vessel steel (ASME SA213 T12), Alloy 28 (UNS N08028) and Alloy 625 (UNS N06625). The results indicated a positive effect in nickel base alloys on corrosion resistance especially of molybdenum but to some extent also of chromium. Nickel, niobium and iron showed no significant effect on corrosion resistance.

  17. Combustion and emissions of the diesel engine using bio-diesel fuel

    Microsoft Academic Search

    Yinnan Yuan; Deqing Mei; Zhong Wang; Tian Zhang

    2008-01-01

    The combustion and heat release of engines using diesel fuel and bio-diesel fuel have been investigated. The results illustrate\\u000a that the combustion happens in advance and the ignition delay period is shortened. The initial heat release peak declines\\u000a a little, the corresponding crankshaft angle changes in advance, and the combustion duration is prolonged. The economic performance\\u000a and emission features of

  18. Thermogravimetric investigation on the degradation properties and combustion performance of bio-oils.

    PubMed

    Ren, Xueyong; Meng, Jiajia; Moore, Andrew M; Chang, Jianmin; Gou, Jinsheng; Park, Sunkyu

    2014-01-01

    The degradation properties and combustion performance of raw bio-oil, aged bio-oil, and bio-oil from torrefied wood were investigated through thermogravimetric analysis. A three-stage process was observed for the degradation of bio-oils, including devolatilization of the aqueous fraction and light compounds, transition of the heavy faction to solid, and combustion of carbonaceous residues. Pyrolysis kinetics parameters were calculated via the reaction order model and 3D-diffusion model, and combustion indexes were used to qualitatively evaluate the thermal profiles of tested bio-oils for comparison with commercial oils such as fuel oils. It was found that aged bio-oil was more thermally instable and produced more combustion-detrimental carbonaceous solid. Raw bio-oil and bio-oil from torrefied wood had comparable combustion performance to fuel oils. It was considered that bio-oil has a potential to be mixed with or totally replace the fuel oils in boilers. PMID:24300845

  19. Low NO/x/ combustion systems for burning heavy residual fuels and high-fuel-bound nitrogen fuels

    NASA Technical Reports Server (NTRS)

    White, D. J.; Batakis, A.; Lecren, R. T.; Yacobucci, H. G.

    1981-01-01

    Design concepts are presented for lean-lean and staged rich-lean combustors. The combustors are designed for the dry reduction of thermal NO(x), control of NO(x) from fuels containing high levels of organic nitrogen, and control of smoke from low hydrogen content fuels. The combustor concepts are tested with a wide variety of fuels including a middle distillate, a petroleum based heavy residual, a coal derived synthetic, and ratios of blends of these fuels. The configurations of the lean-lean and rich-lean combustion systems are provided along with a description of the test rig and test procedure.

  20. Reactivity study on a novel hydrogen fueled chemical-looping combustion

    Microsoft Academic Search

    Hongguang Jin; Masaru Ishida

    2001-01-01

    In this paper the reactivity study on hydrogen fueled chemical-looping combustion, which is capable of making breakthrough in simultaneous contribution to the efficient use of energy and being environmentally benign, has been carried out by a thermogravimetric analyzer (TGA) and a fixed bed reactor. The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions:

  1. CHARACTERIZATION OF EMISSIONS FROM THE COMBUSTION OF WOOD AND ALTERNATIVE FUELS IN A RESIDENTIAL WOODSTOVE

    EPA Science Inventory

    The report gives results of a comparison of emissions from the combustion of alternative fuels to those from wood in a residential woodstove, and of a study of the effects of woodstove operating parameters on combustion emissions. Overall, oak wood is the best fuel tested, consid...

  2. Combustion tests of a turbine simulator burning low Btu fuel from a fixed bed gasifier

    Microsoft Academic Search

    C. S. Cook; N. Abuaf; A. S. Feitelberg; S. L. Hung; D. J. Najewicz; M. S. Samuels

    1993-01-01

    One of the most efficient and environmentally compatible coal fueled power generation technologies is the integrated gasification combined cycle (IGCC) concept. Commercialization of the IGCC\\/HGCU concept requires successful development of combustion systems for high temperature low Btu fuel in gas turbines. Toward this goal, a turbine combustion system simulator has been designed, constructed, and fired with high temperature low Btu

  3. THE INFLUENCE OF CARBON BURNOUT ON SUBMICRON PARTICLE FORMATION FROM EMULSIFIED FUEL OIL COMBUSTION

    EPA Science Inventory

    The paper gives results of an examination of particle behavior and particle size distributions from the combustion of different fuel oils and emulsified fuels in three experimental combusators. Results indicate that improved carbon (C) burnout from fule oil combustion, either by...

  4. Fuel combustion exhibiting low NO{sub x} and CO levels

    DOEpatents

    Keller, J.O.; Bramlette, T.T.; Barr, P.K.

    1996-07-30

    Method and apparatus are disclosed for safely combusting a fuel in such a manner that very low levels of NO{sub x} and CO are produced. The apparatus comprises an inlet line containing a fuel and an inlet line containing an oxidant. Coupled to the fuel line and to the oxidant line is a mixing means for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure, into a combustion region. Coupled to the combustion region is a means for producing a periodic flow field within the combustion region to mix the fuel and the oxidant with ambient gases in order to lower the temperature of combustion. The means for producing a periodic flow field can be a pulse combustor, a rotating band, or a rotating cylinder within an acoustic chamber positioned upstream or downstream of the region of combustion. The mixing means can be a one-way flapper valve; a rotating cylinder; a rotating band having slots that expose open ends of said fuel inlet line and said oxidant inlet line simultaneously; or a set of coaxial fuel annuli and oxidizer annuli. The means for producing a periodic flow field may or may not be in communication with an acoustic resonance. When employed, the acoustic resonance may be upstream or downstream of the region of combustion. 14 figs.

  5. The use of petroleum coke as fuel in chemical-looping combustion

    Microsoft Academic Search

    Henrik Leion; Tobias Mattisson; Anders Lyngfelt

    2007-01-01

    Chemical-looping combustion is a novel technique used for CO2 separation that previously has been demonstrated for gaseous fuel. This work demonstrates the feasibility of using solid fuel (petroleum coke) in chemical-looping combustion (CLC). Here, the reaction between the oxygen carrier and solid fuel occurs via the gasification intermediates, primarily CO and H2. A laboratory fluidized-bed reactor system for solid fuel,

  6. Effect of fuel zinc content on toxicological responses of particulate matter from pellet combustion in vitro.

    PubMed

    Uski, O; Jalava, P I; Happo, M S; Torvela, T; Leskinen, J; Mäki-Paakkanen, J; Tissari, J; Sippula, O; Lamberg, H; Jokiniemi, J; Hirvonen, M-R

    2015-04-01

    Significant amounts of transition metals such as zinc, cadmium and copper can become enriched in the fine particle fraction during biomass combustion with Zn being one of the most abundant transition metals in wood combustion. These metals may have an important role in the toxicological properties of particulate matter (PM). Indeed, many epidemiological studies have found associations between mortality and PM Zn content. The role of Zn toxicity on combustion PM was investigated. Pellets enriched with 170, 480 and 2300 mg Zn/kg of fuel were manufactured. Emission samples were generated using a pellet boiler and the four types of PM samples; native, Zn-low, Zn-medium and Zn-high were collected with an impactor from diluted flue gas. The RAW 264.7 macrophage cell line was exposed for 24h to different doses (15, 50,150 and 300 ?g ml(-1)) of the emission samples to investigate their ability to cause cytotoxicity, to generate reactive oxygen species (ROS), to altering the cell cycle and to trigger genotoxicity as well as to promote inflammation. Zn enriched pellets combusted in a pellet boiler produced emission PM containing ZnO. Even the Zn-low sample caused extensive cell cycle arrest and there was massive cell death of RAW 264.7 macrophages at the two highest PM doses. Moreover, only the Zn-enriched emission samples induced a dose dependent ROS response in the exposed cells. Inflammatory responses were at a low level but macrophage inflammatory protein 2 reached a statistically significant level after exposure of RAW 264.7 macrophages to ZnO containing emission particles. ZnO content of the samples was associated with significant toxicity in almost all measured endpoints. Thus, ZnO may be a key component producing toxicological responses in the PM emissions from efficient wood combustion. Zn as well as the other transition metals, may contribute a significant amount to the ROS responses evoked by ambient PM. PMID:25553547

  7. Nitrogen chemistry during burnout in fuel-staged combustion

    SciTech Connect

    Kristensen, P.G.; Glarborg, P.; Dam-Johansen, K. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering] [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

    1996-11-01

    A parametric study of the chemistry of the burnout zone in reburning has been performed in laboratory plug flow reactors in the temperature range 800--1,350 K. Inlet mole fractions of NO, NH{sub 3}, HCN, CO, and O{sub 2} were varied, together with different temperatures and residence times to simulate reaction conditions in practical systems. Under lean conditions, a minimum in NO emission exists as a function of temperature. Both HCN and NH{sub 3} can act as either NO reductants or as sources for NO by oxidation. Reactions and selectivities for HCN and NH{sub 3} are controlled by the radical pool produced by fuel (CO) oxidation. As increasing amounts of CO were added, temperatures for both ignition and the minimum in NO became lower. At 2% CO, 4% O{sub 2}, and 100 ms residence time, the minimum in NO was found at approximately 1,000 K. At low temperatures, significant amounts of N{sub 2}O were measured in the reactor outlet. This is attributed to N{sub 2}O formation by HCN/NO reactions and to the slow decomposition of N{sub 2}O at these temperatures. Large reductions in NO were seen under fuel-rich conditions and at high temperatures. The observed NO reduction was very much dependent on the inlet mole fraction of O{sub 2}. Detailed chemical kinetic modeling of the experiments showed reasonable predictions for overall fuel-lean conditions, but the model failed to predict experimental results under fuel-rich conditions. The present results provide guidelines for optimizing the conditions for the burnout process of reburning, as well as other processes for NO{sub x} reduction by staged combustion. The results also provide a test basis for verifying kinetic models for nitrogen chemistry at low temperatures (800--1,350 K).

  8. Combustion rates of chars from high-volatile fuels for FBC application

    SciTech Connect

    Masi, S.; Salatino, P.; Senneca, O. [Univ. degli Studi di Napoli Federico II, Napoli (Italy)

    1997-12-31

    The fluidized bed combustion of high volatile fuels is often associated with huge occurrence of comminution phenomena. These result into in-bed generation of substantial amounts of carbon fines which further undergo competitive processes of combustion and elutriation. The small size of carbon fines generated by comminution is such that their further combustion is largely controlled by the intrinsic kinetics of carbon oxidation, alone or in combination with intraparticle diffusion. The competition between fine combustion and elutriation strongly affects the efficiency of fixed carbon conversion and calls for thorough characterization of the combustion kinetics and of residence times of fines in a fluidized bed of coarse solids. In this paper a collection of intrinsic combustion kinetic and porosimetric data for chars from three high-volatile fuels suitable for FBC application is presented. Chars from a Refuse Derived Fuel (RDF), a Tyre Derived Fuel (TDF) and a biomass (Robinia Pseudoacacia) are obtained from devolatilization, in fluidized bed, of fuel samples. Thermogravimetric analysis, mercury porosimetry and helium pycnometry are used to characterize the reactivity and the pore structure of the chars. Combustion rates are characterized over a wide range of temperatures (320--850 C) and oxygen partial pressures, covering the entire range of interest in fluidized bed combustion. Analysis of thermogravimetric and porosimetric data is directed to obtaining the parameters (pre-exponential factors, reaction orders, activation energies, intraparticle diffusivities) of combustion kinetic submodels for application in fluidized bed combustor modeling.

  9. Combustion Study of Stabilized Water-in-Diesel Fuel Emulsion

    Microsoft Academic Search

    M. Y. E. Selim; M. T. Ghannam

    2009-01-01

    An experimental investigation has been carried out to produce a stable diesel\\/water emulsion fuel and use it in a diesel engine under different operating and design conditions. The emulsion stayed stable for up to 30% water in diesel for up to one week and 20% water in diesel for four weeks. The physical properties of the stable W\\/D emulsions in

  10. Characterization of Melaleuca biomass as a fuel for direct combustion

    Microsoft Academic Search

    S. Wang; J. B. Huffman; R. C. Littel

    1981-01-01

    Selected properties of Melaleuca quinquenervia biomass were determined to evaluate its quality as a fuel. Ten trees were sampled from 2 areas (Lee and Dade Counties) in Florida. Test materials were sampled from: stem discs at 4 different heights; terminal branches; and foliage. Average heat values (cal\\/g) were 4400, 6160, 4610 and 4810 for wood and bark, terminal branches and

  11. Adaptation of Combustion Principles to Aircraft Propulsion. Volume I; Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C (Editor); Hibbard, Robert R (Editor)

    1955-01-01

    The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.

  12. Pozzolanic properties of pulverized coal combustion bottom ash

    Microsoft Academic Search

    M. Cheriaf; J. Cavalcante Rocha; J. Péra

    1999-01-01

    The pozzolanic properties of a coal combustion bottom ash were investigated. Plain pastes containing equal amounts of calcium hydroxide and bottom ash were prepared and analyzed at different ages for their strength and the calcium hydroxide consumption. At early ages, bottom ash does not react with calcium hydroxide. Its pozzolanic reaction proceeds slowly and accelerates gradually to become very interesting

  13. Experimental study of combustion of hydrogen–syngas\\/methane fuel mixtures in a porous burner

    Microsoft Academic Search

    S. K. Alavandi; A. K. Agrawal

    2008-01-01

    Lean premixed combustion of hydrogen–syngas\\/methane fuel mixtures was investigated experimentally to demonstrate fuel flexibility of a two-section porous burner. The un-insulated burner was operated at atmospheric pressure. Combustion was stabilized at the interface of silicon-carbide coated carbon foam of 26 pores per centimeter (ppcm) and 4ppcm. Methane (CH4) content in the fuel was decreased from 100% to 0% (by volume),

  14. Internal combustion engine cylinder-to-cylinder balancing with balanced air-fuel ratios

    DOEpatents

    Harris, Ralph E.; Bourn, Gary D.; Smalley, Anthony J.

    2006-01-03

    A method of balancing combustion among cylinders of an internal combustion engine. For each cylinder, a normalized peak firing pressure is calculated as the ratio of its peak firing pressure to its combustion pressure. Each cylinder's normalized peak firing pressure is compared to a target value for normalized peak firing pressure. The fuel flow is adjusted to any cylinder whose normalized peak firing pressure is not substantially equal to the target value.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 7, October 1990--December 1990

    SciTech Connect

    Hargrove, M.J.; Chow, O.K.; Nsakala, N.Y.

    1991-02-01

    During the fourth quarter of 1990, the following technical progress was made: (1) Calculated the kinetic characteristics of chars from the combustion of microbubble flotation beneficiated products; (2) continued drop tube combustion tests of the spherical oil agglomeration beneficiated products; (3) analyzed the data from three (MIT) pilot-scale combustion tests of the Upper Freeport feed coal; and (4) continued analyses of the data from the CE pilot-scale tests of nine fuels.

  16. Combustion of liquid bio-fuels in an internal circulating fluidized bed

    Microsoft Academic Search

    Francesco Miccio; Sylwester Kalisz; David Baxter; Karel Svoboda

    2008-01-01

    The paper presents novel experimental results for the combustion of liquid bio-fuels in an internal circulating fluidized bed (ICFB). A 20kW experimental facility equipped with an air-assisted injector has been used. Reliable operation, high combustion efficiency and limited temperature increase along the combustion riser tube have been attained at different operating conditions. However, CO emission has been rather higher than

  17. Combustion quasi-two zone predictive model for dual fuel engines

    Microsoft Academic Search

    G. H. Abd Alla; H. A. Soliman; O. A. Badr; M. F. Abd Rabbo

    2001-01-01

    A quasi-two zone predictive model is developed in the present work for prediction of the combustion processes in dual fuel engines and some of their performance features. Methane is used as the main fuel while employing a small quantity of liquid fuel (pilot) injected through the conventional Diesel fuel system. This model emphasizes the effects of chemical kinetics activity of

  18. Public perception related to a hydrogen hybrid internal combustion engine transit bus demonstration and hydrogen fuel

    Microsoft Academic Search

    Allister Hickson; Al Phillips; Gene Morales

    2007-01-01

    Hydrogen has been widely considered as a potentially viable alternative to fossil fuels for use in transportation. In addition to price competitiveness with fossil fuels, a key to its adoption will be public perceptions of hydrogen technologies and hydrogen fuel. This paper examines public perceptions of riders of a hydrogen hybrid internal combustion engine bus and hydrogen as a fuel

  19. Theoretical and experimental studies on the combustion of synthetic fuels in spark ignition engines

    Microsoft Academic Search

    A. A. Desoky; S. M. El-Eman

    1983-01-01

    The incentives for studying the combustion of alternative fuels in engines are, some fuel as fuel additive may solve the problem of emissions, knock, derivability and efficiency. Also an alternative fuel may help conserve the world's petroleum supplies as well as being available when those supplies are exhausted. Transportation is unique among the energy consuming sectors of the economy of

  20. Trapped Vortex Combustion Chamber: Design and Experimental Investigations Using Hydrogen as Fuel

    NASA Astrophysics Data System (ADS)

    Kulshreshtha, D. B.; Channiwala, S. A.

    2014-01-01

    The design of trapped vortex combustion chamber was undertaken as a part of ongoing research on micro combustion chamber using hydrogen as fuel. The reacting experimental studies were then carried out on the designed chamber. The fuel was injected directly into the cavity. The combustion was first initiated in the cavity with 3 % of the main flow air supplied in reverse direction to the fuel flow. The combustion in cavity was of rich type. Temperature levels in the range of 900 K were encountered in the cavity. Thereafter, diffusion combustion was initiated using the flame generated in the cavity. The temperature levels in this stage were in the range of 1,800 K. The overall pressure drop for a trapped vortex combustor was less than 5 % at all operating parameters.

  1. Effect of a homogeneous combustion catalyst on the combustion characteristics and fuel efficiency in a diesel engine

    Microsoft Academic Search

    Mingming Zhu; Yu Ma; Dongke Zhang

    2012-01-01

    â–ş A ferrous-picrate catalyst has been shown to improve diesel engine efficiency. â–ş The fuel consumption is reduced by up to 4.2% with the use of the catalyst. â–ş The catalyst shortens ignition delay and combustion duration.

  2. Investigation of thermal and environmental characteristics of combustion of gaseous fuels

    NASA Astrophysics Data System (ADS)

    Vetkin, A. V.; Suris, A. L.

    2015-03-01

    Numerical investigations are fulfilled for some thermal and environmental characteristics of combustion of gaseous fuels used at present in tube furnaces of petroleum refineries. The effect of the fuel composition on these characteristics is shown and probable consequences of the substitution of natural gas to other types of fuels. Methane, ethane, propane, butane, propylene, and hydrogen are considered for comparison, which in most cases are constituents of the composition of the fuel burnt in furnaces. The effect of the fuel type, its associated combustion temperature, combustion product emissivity, temperature of combustion chamber walls, mean beam length, and heat release on the variation in the radiant heat flux within the radiant chamber of furnaces is investigated. The effect of flame characteristics, which are determined by the presence of diffusion combustion zones formed by burners used at present in furnaces for reducing nitrogen oxides emission, is analyzed. The effect of the fuel type on the equilibrium NO concentration is also investigated. The investigations were carried out both at arbitrary given gas temperatures and at effective temperatures dependent on the adiabatic combustion temperature and the temperature at the chamber output and determined based on solving a set of equations at various heat-release rates of the combustion chamber.

  3. Advanced fuel system technology for utilizing broadened property aircraft fuels

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    Possible changes in fuel properties are identified based on current trends and projections. The effect of those changes with respect to the aircraft fuel system are examined and some technological approaches to utilizing those fuels are described.

  4. Effect of secondary fuels and combustor temperature on mercury speciation in pulverized fuel co-combustion: part 1

    SciTech Connect

    Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

    2007-08-15

    The present work mainly involves bench scale studies to investigate partitioning of mercury in pulverized fuel co-combustion at 1000 and 1300{sup o}C. High volatile bituminous coal is used as a reference case and chicken manure, olive residue, and B quality (demolition) wood are used as secondary fuels with 10 and 20% thermal shares. The combustion experiments are carried out in an entrained flow reactor with a fuel input of 7-8 kWth. Elemental and total gaseous mercury concentrations in the flue gas of the reactor are measured on-line, and ash is analyzed for particulate mercury along with other elemental and surface properties. Animal waste like chicken manure behaves very differently from plant waste. The higher chlorine contents of chicken manure cause higher ionic mercury concentrations whereas even with high unburnt carbon, particulate mercury reduces with increase in the chicken manure share. This might be a problem due to coarse fuel particles, low surface area, and iron contents. B-wood and olive residue cofiring reduces the emission of total gaseous mercury and increases particulate mercury capture due to unburnt carbon formed, fine particles, and iron contents of the ash. Calcium in chicken manure does not show any effect on particulate or gaseous mercury. It is probably due to a higher calcium sulfation rate in the presence of high sulfur and chlorine contents. However, in plant waste cofiring, calcium may have reacted with chlorine to reduce ionic mercury to its elemental form. According to thermodynamic predictions, almost 50% of the total ash is melted to form slag at 1300{sup o}C in cofiring because of high calcium, iron, and potassium and hence mercury and other remaining metals are concentrated in small amounts of ash and show an increase at higher temperatures. No slag formation was predicted at 1000{sup o}C. 24 refs., 8 figs., 4 tabs.

  5. Process and apparatus for the instantaneous combustion of diafanous liquid petroleum, diesel or similar fuels

    Microsoft Academic Search

    1980-01-01

    A process and apparatus for the production of heat, equivalent in clarity and cleanliness to that of propane, butane or natural gas, but at a lower cost and without the problems or dangers of storage nor risks of fire or explosion during handling, by means of the instantaneous combustion of diafanous liquid petroleum, diesel or other similar combustible fuels mixed

  6. Experimental investigation on the combustion characteristics of a diesel engine fueled with Jatropha curcas oil

    Microsoft Academic Search

    Liang Yu; Zhou Li-ying; Wang Zi-yu; Guo Jian; Luo Fu-qiang

    2011-01-01

    the structure of the diesel engine, the Indicator Diagram of the diesel engine is measured by when it is fueled with diesel, jatropha curcas oil and preheated jatropha curcas oil (150°C) at different conditions. Then the combustion characteristics are analyzed by studying the Indicator Diagram. The results showe that the timing of combustion advances, the maximum value of heat release

  7. MODELING COMBUSTION CHAMBER DYNAMICS OF IMPINGING STREAM VORTEX ENGINES FUELED WITH HYDRAZINE-ALTERNATIVE HYPERGOLS

    Microsoft Academic Search

    C.-C. Chen; M. J. Nusca; M. J. McQuaid

    To advance the development of Impinging Stream Vortex Engines (ISVEs) for tactical missile propulsion system applications, a computational fluid dynamics (CFD) modeling capability has been developed and employed to simulate the combustion chamber dynamics of various ISVE designs. Simulations of first- generation ISVE configurations fueled with mono- methylhydrazine\\/red fuming nitric acid (MMH\\/RFNA) led to insights that inspired a combustion chamber

  8. Performance of a controllable premixed combustion engine fueled with dimethyl ether

    Microsoft Academic Search

    Jun Song; Zhen Huang; Xinqi Qiao; Wanli Wang

    2004-01-01

    This paper presents a new concept of the controllable premixed combustion (CPC) for an internal combustion engine fueled with dimethyl ether (DME). The CPC system is composed of an electronic control low pressure injection system, a premix chamber and a main chamber. Between the two chambers, a control valve is set. DME is entirely injected into the premix chamber at

  9. The NASA broad specification fuels combustion technology program at Pratt and Whitney

    NASA Technical Reports Server (NTRS)

    Lohmann, R. P.

    1984-01-01

    The technology required to accommodate the use of broadened properties fuels in commercial aircraft engine combustors with minimum impact on the emissions, performance, durability and engine operational characteristics is discussed. Emphasis was placed on defining the potential for reducing the fuel sensitivity of the reference combustion system through design refinements and the introduction of more advanced technology combustors. To this end the tests conducted included the evaluation of variations of three different combustor concepts representing progressively more advanced technology levels. It was demonstrated that reduced fuel hydrogen content has adverse impacts on current single stage combustors; the best opportunities for reducing the fuel sensitivity of these combustors are through improved fuel injectors and advanced liner cooling and structural concepts and that the advanced technology staged and variable geometry combustor concepts have inherent operational flexibility that can be exploited to accommodate changes in fuel composition. Also, advanced technology combustor concepts were evaluated. A variable geometry combustor capable of airflow modulation during operation and a new concept which is a further evolution of the Vorbix combustor are discussed.

  10. Perovskite membranes by aqueous combustion synthesis: synthesis and properties

    Microsoft Academic Search

    Alexander S. Mukasyan; Colleen Costello; Katherine P. Sherlock; David Lafarga; Arvind Varma

    2001-01-01

    The objective of this work is to identify optimum synthesis, compacting and sintering conditions in order to achieve a pure phase fully densified La0.8Sr0.2CrO3 (LSC) perovskite membrane. The aqueous combustion synthesis of LSC powders was investigated over a wide range of synthesis conditions by using the metal nitrates (oxidizer)–glycine (fuel) system. The powders were pressed and sintered to create dense

  11. Effect of air-staging on mercury speciation in pulverized fuel co-combustion: part 2

    SciTech Connect

    Shishir P. Sable; Wiebren de Jong; Ruud Meij; Hartmut Spliethoff [Delft University Technology, Delft (Netherlands). Section Energy Technology, Department of Process and Energy

    2007-08-15

    The concerns regarding global warming and need for new energy resources brought the concept of biomass and waste as secondary fuels to the power industry. Mercury emissions in cases of cofiring of chicken manure, olive residue, and B-wood with a high volatile bituminous coal blend are studied in the first part of this paper. The use of secondary fuels significantly affects NOx emissions due to different types of nitrogen present in the fuel matrix. Air-staging is a proven in-furnace NOx reduction technology. The present work mainly involves bench scale studies to investigate the effect of air-staging on partitioning of mercury in pulverized fuel co-combustion. The combustion experiments are carried out in an entrained flow reactor at 1300{sup o}C with a 20%th share of secondary fuels. Elemental and total gaseous mercury from the reactor is measured on-line, and ash is analyzed for particulate mercury along with elemental and surface properties. Reducing the air stoichiometry in the primary zone of the combustor increases unburnt carbon which in turn reduces mercury emissions in the gas phase. Ash analysis shows the effect of surface area, particle size, and unburnt carbon on mercury capture. Calcium variation in the ash was observed due to formation of different slag in reducing and oxidizing conditions and might have affected the mercury capture in combination with the above parameters. A low iron concentration of ash does not seem to affect the capture of mercury. The results will help in predicting different forms of mercury emitted from the furnace at desired operating conditions which will eventually form the basis for the design of the control strategies for mercury emissions. 22 refs., 3 figs., 1 tab.

  12. Pressure-coupled vaporization and combustion responses of liquid-fuel droplets in high-pressure environments

    NASA Technical Reports Server (NTRS)

    Yang, Vigor; Shuen, J. S.; Hsiao, C. C.

    1991-01-01

    The dynamic responses of liquid-fuel droplet vaporization and combustion to ambient pressure oscillations are examined. The analysis is based on the complete sets of conservation equations for both gas and liquid phases, and accommodates detailed treatments of finite-rate chemical kinetics and variable properties. With a full account of thermodynamic phase equilibrium at the droplet surface, the model enables a systematic examination of the effects of ambient flow conditions on the droplet behavior. The responses of hydrocarbon fuel droplets in both sub- and super-critical environments are investigated. Results indicate that the droplet gasification and burning mechanisms depend greatly on the ambient pressure. In particular, a rapid enlargement of the vaporization and combustion responses occurs when the droplet surface reaches its critical point, mainly due to the strong variations of latent heat of vaporization and thermophysical properties at the critical state.

  13. Fuel system design concepts for broad property fuels

    NASA Technical Reports Server (NTRS)

    Versaw, E. F.

    1984-01-01

    The results of a study assessing the impact of using jet fuel with relaxed specification properties on an aircraft fuel system are given. The study objectives were to identify credible values for specific fuel properties which might be relaxed, to evolve advanced fuel system designs for airframe and engines which would permit use of the specified relaxed properties fuels, and to evaluate performance of the candidate advanced fuel systems and the relaxed property fuels in a typical transport aircraft. The study used, as a baseline, the fuel system incorporated in the Lockheed Tristar. This aircraft is powered by three RB.211-524 Rolls-Royce engines and incorporates a Pratt and Whitney ST6C-421 auxiliary power unit for engine starting and inflight emergency electrical power. The fuel property limits examined are compared with commercial Jet A kerosene and the NASA RFP fuel properties. A screening of these properties established that a higher freezing point and a lower thermal stability would impact fuel system design more significantly than any of the other property changes. Three candidate fuel systems which combine the ability to operate with fuels having both a high freeze point and a low thermal stability are described. All candidates employ bleed air to melt fuel freeze-out prior to starting the APU or an inoperable engine. The effects of incorporating these systems on aircraft weight and engine specific fuel consumption are given.

  14. Chemical Properties of Combustion Aerosols: An Overview

    EPA Science Inventory

    A wide variety of pyrogenic and anthropogenic sources emit fine aerosols to the atmosphere. The physical and chemical properties of these aerosols are of interest due to their influence on climate, human health, and visibility. Aerosol chemical composition is remarkably complex. ...

  15. New mixture formation technology of direct fuel injection stratified combustion SI engine (OSKA)

    SciTech Connect

    Kato, S.; Onishi, S.

    1987-01-01

    A new type of internal combustion engine has been developed. The new idea incorporates an impinging part in the central piston cavity. The fuel spray is injected against the impinging area, spreads and forms a fuel mixture. Since a comparatively rich fuel mixture, always stays around the impinging part and ignition is accomplished at the center of the rich fuel mixture, steady, instantaneous and high-speed combustion is possible. As the fuel mixture is always formed in the cavity, there is little fuel in the squish area. Therefore, it is possible to prevent end-gas knocking, and in spite of the use of spark ignition, to operate the engine at higher compression ratio than a conventional premixed SI engine. Experiments with methanol fuel showed that BMEP was 1.1MPa and the maximum brake thermal efficiency was 42%. The combustion noise was lower than that of diesel engine. Brief tests with gasoline showed a maximum brake thermal efficency of 36%.

  16. Effect of Different Binders on the Combustion Properties of Lignite Part I. Effect on thermal properties

    Microsoft Academic Search

    N. E. Altun; C. Hicyilmaz; M. V. Kök

    2001-01-01

    Coal briquettes and the binders were tested from the view of resistivity to transportation, loading and storage by measuring\\u000a the abrasion index and strength to crushing. The binders used in coal briquetting also affect the combustion properties of\\u000a the coal. Combustion properties of the Tuncbilek lignite and different binders were analysed by thermogravimetric (TG\\/DTG)\\u000a methods. Molasses, carboxyl methylcellulose (CMC), sulphide

  17. Solid Fuel Delivery System Developed for Combustion Testing on the International Space Station

    NASA Technical Reports Server (NTRS)

    Frate, David T.

    2004-01-01

    NASA initiated Bioastronautics and Human Research Initiatives in 2001 and 2003, respectively, to enhance the safety and performance of humans in space. The Flow Enclosure Accommodating Novel Investigations in Combustion of Solids (FEANICS) is a multiuser facility being built at the NASA Glenn Research Center to advance these initiatives by studying fire safety and the combustion of solid fuels in the microgravity environment of the International Space Station (ISS). One of the challenges for the FEANICS team was to build a system that allowed for several consecutive combustion tests to be performed with minimal astronaut crew interaction. FEANICS developed a fuel carousel that contains a various number of fuel samples, depending on the fuel width, and introduces them one at a time into a flow tunnel in which the combustion testing takes place. This approach will allow the science team to run the experiments from the ground, while only requiring the crew to change out carousels after several tests have been completed.

  18. Techno-economic analysis of pressurized oxy-fuel combustion power cycle for CO? capture

    E-print Network

    Hong, Jongsup

    2009-01-01

    Growing concerns over greenhouse gas emissions have driven extensive research into new power generation cycles that enable carbon dioxide capture and sequestration. In this regard, oxy-fuel combustion is a promising new ...

  19. Chemical kinetic modeling of oxy-fuel combustion of sour gas for enhanced oil recovery

    E-print Network

    Bongartz, Dominik

    2014-01-01

    Oxy-fuel combustion of sour gas, a mixture of natural gas (primarily methane (CH 4 )), carbon dioxide (CO 2 ), and hydrogen sulfide (H 2 S), could enable the utilization of large natural gas resources, especially when ...

  20. Estimation of Fuel Savings by Recuperation of Furnace Exhausts to Preheat Combustion Air

    E-print Network

    Rebello, W. J.; Kohnken, K. H.; Phipps, H. R., Jr.

    1980-01-01

    ESTIMATION OF FUEL SAVINGS BY RECUPERATION OF FURNACE EXHAUSTS TO PREHEAT COMBUSTION AIR Wilfred J. Rebello PAR Enterprises Inc. , Fairfax, VA Kent H. Kohnken GTE Products Corp., Towanda, PA Harold R. Phipps Jr. Systems Consultants Inc...

  1. Non-LTE thermodynamic properties for combustion processes

    SciTech Connect

    Fentress, M.L.; Eddy, T.L.

    1987-09-01

    The nonequilibrium thermodynamic properties of a product-gas derived from fluidized combustion of Pittsburgh seam coal is obtained using a multitemperature statistical thermodynamic computer model. Concentrations of 18 species are determined as a function of translational temperature (500 < T < 2500 K), pressure (0.1, 1.0, and 10 atm), and vibrational-to-translational temperature ratios of 0.5, 1, 2, and 5. The rotational and electronic excitation temperatures are assumed equal to the translational temperature. The partition functions and usual thermodynamic properties are also calculated and a nonequilibrium Mollier diagram is presented. The multitemperature model assumes chemical equilibrium and therefore represents a first step in describing nonequilibrium combustion reactions in a semiclassical manner. The model can be applied to reactions via chemical kinetics and/or an extension to a multichemical nonequilibrium model. The results indicate the relative concentration of species usually considered to be pollutants, under the range of conditions examined.

  2. Liquid fuel combustion within silicon-carbide coated carbon foam

    Microsoft Academic Search

    S. Vijaykant; Ajay K. Agrawal

    2007-01-01

    Combustion of kerosene inside porous inert medium (PIM) has been investigated with the goal of reducing the emissions of nitric oxides (NOâ), carbon monoxide (CO) and soot. Silicon-carbide (SiC) coated carbon foam is used as PIM to attain high structural strength. The two-zone porous burner design consists of preheat and combustion sections. Different PIM configurations were tested by stacking together

  3. Liquid fuel combustion within silicon-carbide coated carbon foam

    Microsoft Academic Search

    S. Vijaykant; Ajay K. Agrawal

    2007-01-01

    Combustion of kerosene inside porous inert medium (PIM) has been investigated with the goal of reducing the emissions of nitric oxides (NOx), carbon monoxide (CO) and soot. Silicon-carbide (SiC) coated carbon foam is used as PIM to attain high structural strength. The two-zone porous burner design consists of preheat and combustion sections. Different PIM configurations were tested by stacking together

  4. Oxy-Fuel Combustion of Pulverized Coal: Characterization, Fundamentals, Stabilization and CFD Modeling

    Microsoft Academic Search

    Lei Chen; Sze Zheng Yong; Ahmed F. Ghoniem

    Oxy-fuel combustion has generated significant interest since it was proposed as a carbon capture technology for newly built and retrofitted coal-fired power plants. Research, development and demonstration of oxy-fuel combustion technologies has been advancing in recent years; however, there are still fundamental issues and technological challenges that must be addressed before this technology can reach its full potential, especially in

  5. The potential for clean energy production using oxy-fuel combustion and integrated pollutant removal

    SciTech Connect

    Ochs, Thomas L.; Oryshchyn, Danylo B.; Weber, Thomas (Jupiter Oxygen Corporation, Schiller Park, IL 60176).; Summers, Cathy A.

    2005-05-01

    Effective remediation of flue gas produced by an oxy-fuel coal combustion process has been proven at bench scale in the course of cooperative research between USDOE’s Albany Research Center (ARC) and Jupiter Oxygen Corporation. All combustion gas pollutants were captured, including CO2 which was compressed to a liquefied state suitable for sequestration. Current laboratory-scale research and the future of combined oxy-fuel/IPR systems are discussed.

  6. The origin of organic pollutants from the combustion of alternative fuels: Phase IV report

    Microsoft Academic Search

    P. H. Taylor; B. Dellinger; S. K. Sidhu

    1997-01-01

    As part of the US-DOE`s on-going interest in the use of alternative automotive fuels, the University of Dayton Research Institute has been conducting research on pollutant emissions resulting from the combustion of candidate fuels. This research, under the direction and sponsorship of the NREL, has been concerned primarily with the combustion of compressed natural gas, liquefied petroleum gas (LPG), methanol,

  7. Comparative second-law analysis of internal combustion engine operation for methane, methanol, and dodecane fuels

    Microsoft Academic Search

    C. D Rakopoulos; D. C Kyritsis

    2001-01-01

    A method for both combustion irreversibility and working medium availability computations in a high-speed, naturally-aspirated, four-stroke, internal combustion engine cylinder is presented. The results of the second-law analysis of engine operation with n-dodecane (n-C12H26) fuel are compared with the results of a similar analysis for cases where a light, gaseous (CH4) and an oxygenated (CH3OH) fuel is used. The rate

  8. Systematic assessment of combustion characteristics of biofuels and emulsions with water for use as diesel engine fuels

    Microsoft Academic Search

    Roy J. Crookes; Fariborz Kiannejad; Marouan A. A. Nazha

    1997-01-01

    Measurements of the combustion performance of biofuel oils, blends with diesel fuel and emulsions with water have been made, using a variety of experimental techniques. Photographic examination of single droplets demonstrated similar burning rates to diesel fuel. High speed records revealed the explosive combustion of oil-water emulsion droplets. Spray-flame photography showed up the poor combustion efficiency at atmospheric pressure, of

  9. 1 Characterization of carbonaceous aerosols outflow from India and 2 Arabia: Biomass/biofuel burning and fossil fuel combustion

    E-print Network

    Dickerson, Russell R.

    /biofuel burning and fossil fuel combustion 3 S. A. Guazzotti,1 D. T. Suess,1,2 K. R. Coffee,1,3 P. K. Quinn,4 T. S with potassium 17 (indicative of combustion sources), and mass concentration of submicrometer non-sea- 18 salt Peninsula, where dominance of fossil fuel combustion is suggested by 30 results from single

  10. Hydrocarbon-fueled internal combustion engines: "the worst form of vehicle propulsion... except for all the other forms"

    E-print Network

    Hydrocarbon-fueled internal combustion engines: "the worst form of vehicle propulsion... except of Southern California, Los Angeles, CA 90089-1453 Introduction Hydrocarbon-fueled internal combustion engines system paradigm are discussed. First a definition of an internal combustion engine is needed

  11. The Simulation of Using Hydrogen Fuel in Gasoline Internal Combustion Engines. ?????? ?????? ?? ???

    Microsoft Academic Search

    Mohammed Awwad Al-Dabbas; Ammar Ahmed Al-Rousan

    Ultimately, the use of hydrogen fuel produced from renewable energy sources could solve the air pollution, global warming, and energy security problems associated with today's fossil fuel- powered passenger vehicles. Although commercial applications of hydrogen fuel cell technology for passenger vehicles are still over a decade away, optimization of today's hybrid internal combustion engines (ICE) to run on hydrogen may

  12. Combustion of Liquid Fuels Spilled on Water. Prediction of Time to Start of Boilover

    Microsoft Academic Search

    J. P. GARO; P. GILLARD; J. P. VANTELON; A. C. FERNANDEZ-PELLO

    1999-01-01

    The combustion of a liquid fuel floating on water is a problem of interest because of its potential environmental and safety consequences. When a liquid fuel is burning under these conditions, the presence of the water may cause some particular effects due to heat transfer to the water. If the fuel layer is thin, heat losses to the water may

  13. Reducing Cyclic Dispersion in Autoignition Combustion by Controlling Fuel Injection Timing

    E-print Network

    Stefanopoulou, Anna

    Reducing Cyclic Dispersion in Autoignition Combustion by Controlling Fuel Injection Timing Erik here to include the effect of the fuel injection timing, which is an effective way of influencing and that significantly affect the dynamic evolution [2], [3]. The approach here is to control the timing of the fuel

  14. Determining size of drops in fuel mixture of internal combustion engines

    NASA Technical Reports Server (NTRS)

    Sauter, J

    1926-01-01

    In compressorless Diesel engines and in explosion engines using fuels with high boiling points it is difficult to effect a good combustion of the fuel mixture. This report presents different methods for calculating the size and uniformity of fuel droplets and mixtures.

  15. Electronic fuel supply control system for internal combustion engines, having exhaust gas recirculation control

    Microsoft Academic Search

    A. Yamato; S. Umesaki

    1984-01-01

    In an electronic fuel supply control system for an internal combustion engines, the fuel quantity being supplied to the engine is set to different values in accordance with the operating condition of the engine, between when the exhaust gas recirculation is operated and when it is not operated, for achieving proper air\\/fuel ratios. Further, immediately after a valve lift command

  16. Fuel supply control method for internal combustion engines after starting in hot state

    Microsoft Academic Search

    A. Fujimura; Y. Wazaki

    1988-01-01

    This patent describes a method of controlling the supply of fuel to an internal combustion engine, including the steps of effecting after-start fuel increasing control wherein an initial value of a fuel increment is set to a value dependent upon a temperature of the engine upon generation of a predetermined control signal immediately after the start of the engine, the

  17. Method of controlling fuel supply to an internal combustion engine at deceleration

    Microsoft Academic Search

    A. Yamato; T. Nishikawa

    1988-01-01

    This patent describes a method of controlling the fuel supply to an internal combustion engine at deceleration. The engine has an intake passage, wherein (i) the fuel supply to the engine is decreased when the engine is in a first predetermined operating region where leaning of the air-fuel mixture is required when the pressure in the intake passage is lower

  18. Compression ignition engine having fuel system for non-sooting combustion and method

    SciTech Connect

    Bazyn, Timothy; Gehrke, Christopher

    2014-10-28

    A direct injection compression ignition internal combustion engine includes a fuel system having a nozzle extending into a cylinder of the engine and a plurality of spray orifices formed in the nozzle. Each of the spray orifices has an inner diameter dimension of about 0.09 mm or less, and define inter-orifice angles between adjacent spray orifice center axes of about 36.degree. or greater such that spray plumes of injected fuel from each of the spray orifices combust within the cylinder according to a non-sooting lifted flame and gas entrainment combustion pattern. Related methodology is also disclosed.

  19. Biomass Fuel Characterization : Testing and Evaluating the Combustion Characteristics of Selected Biomass Fuels : Final Report May 1, 1988-July, 1989.

    SciTech Connect

    Bushnell, Dwight J.; Haluzok, Charles; Dadkhah-Nikoo, Abbas

    1990-04-01

    Results show that two very important measures of combustion efficiency (gas temperature and carbon dioxide based efficiency) varied by only 5.2 and 5.4 percent respectively. This indicates that all nine different wood fuel pellet types behave very similarly under the prescribed range of operating parameters. The overall mean efficiency for all tests was 82.1 percent and the overall mean temperature was 1420 1{degree}F. Particulate (fly ash) ad combustible (in fly ash) data should the greatest variability. There was evidence of a relationship between maximum values for both particulate and combustible and the percentages of ash and chlorine in the pellet fuel. The greater the percentage of ash and chlorine (salt), the greater was the fly ash problem, also, combustion efficiency was decreased by combustible losses (unburned hydrocarbons) in the fly ash. Carbon monoxide and Oxides of Nitrogen showed the next greatest variability, but neither had data values greater than 215.0 parts per million (215.0 ppm is a very small quantity, i.e. 1 ppm = .001 grams/liter = 6.2E-5 1bm/ft{sup 3}). Visual evidence indicates that pellets fuels produced from salt laden material are corrosive, produce the largest quantities of ash, and form the only slag or clinker formations of all nine fuels. The corrosion is directly attributable to salt content (or more specifically, chloride ions and compounds formed during combustion). 45 refs., 23 figs., 19 tabs.

  20. Combustion tests of beneficiated and micronized coal-water fuels: use of internal-mix atomizer and rotary-cup burner

    Microsoft Academic Search

    Y. C. Fu; G. T. Bellas; T. D. Brown; J. I. Joubert; G. F. Walbert

    1985-01-01

    Combustion tests were conducted in an oil-designed 100-hp firetube boiler using a burner with an internal-mix atomizer to determine the effect of coal beneficiation and coal particle size-consist on combustion properties of coal-water fuels (CWF). Samples of Eastern Kentucky bituminous coal, beneficiated to ash levels of 2.5%, 7.8%, and 10.3%, were used to prepare CWF's containing approx. 90% (by weight)

  1. Physical properties of low molecular weight triglycerides for the development of bio-diesel fuel models

    Microsoft Academic Search

    John W. Goodrum; Mark A. Eiteman

    1996-01-01

    To aid the improvement of fuel properties of oils, basic physical and combustion-related properties of low molecular weight triglycerides are described. These properties include density, viscosity, heat capacity, surface tension and vapor pressure. Fuel injection atomization factors were determined for these triglycerides. Properties of tributyrin (C4:0), tricaproin (C6:0), tricaprylin (C8:0) and tricaprin (C10:0) indicate that these triglycerides are potential components

  2. Parametric examination of the destruction of availability due to combustion for a range of conditions and fuels

    E-print Network

    Chavannavar, Praveen Shivshankar

    2005-11-01

    A comprehensive second law analysis of combustion for a range of conditions and fuels was completed. Constant pressure, constant volume and constant temperature combustion processes were examined. The parameters studied were reactant temperature...

  3. Parametric examination of the destruction of availability due to combustion for a range of conditions and fuels 

    E-print Network

    Chavannavar, Praveen Shivshankar

    2005-11-01

    A comprehensive second law analysis of combustion for a range of conditions and fuels was completed. Constant pressure, constant volume and constant temperature combustion processes were examined. The parameters studied were reactant temperature...

  4. Performance Evaluation and Optimization of Diesel Fuel Properties and Chemistry in an HCCI Engine

    SciTech Connect

    Bunting, Bruce G [ORNL] [ORNL; Eaton, Scott J [ORNL] [ORNL; Crawford, Robert W [Rincon Ranch Consulting] [Rincon Ranch Consulting

    2009-01-01

    The nine CRC fuels for advanced combustion engines (FACE fuels) have been evaluated in a simple, premixed HCCI engine under varying conditions of fuel rate, air-fuel ratio, and intake temperature. Engine performance was found to vary mainly as a function of combustion phasing as affected by fuel cetane and engine control variables. The data was modeled using statistical techniques involving eigenvector representation of the fuel properties and engine control variables, to define engine response and allow optimization across the fuels for best fuel efficiency. In general, the independent manipulation of intake temperature and air-fuel ratio provided some opportunity for improving combustion efficiency of a specific fuel beyond the direct effect of targeting the optimum combustion phasing of the engine (near 5 CAD ATDC). High cetane fuels suffer performance loss due to easier ignition, resulting in lower intake temperatures, which increase HC and CO emissions and result in the need for more advanced combustion phasing. The FACE fuels also varied in T90 temperature and % aromatics, independent of cetane number. T90 temperature was found to have an effect on engine performance when combined with high centane, but % aromatics did not, when evaluated independently of cetane and T90.

  5. Advanced fuel system technology for utilizing broadened property aircraft fuels

    NASA Technical Reports Server (NTRS)

    Reck, G. M.

    1980-01-01

    Factors which will determine the future supply and cost of aviation turbine fuels are discussed. The most significant fuel properties of volatility, fluidity, composition, and thermal stability are discussed along with the boiling ranges of gasoline, naphtha jet fuels, kerosene, and diesel oil. Tests were made to simulate the low temperature of an aircraft fuel tank to determine fuel tank temperatures for a 9100-km flight with and without fuel heating; the effect of N content in oil-shale derived fuels on the Jet Fuel Thermal Oxidation Tester breakpoint temperature was measured. Finally, compatibility of non-metallic gaskets, sealants, and coatings with increased aromatic content jet fuels was examined.

  6. Cyclic Combustion Variations in Dual Fuel Partially Premixed Pilot-Ignited Natural Gas Engines

    SciTech Connect

    Srinivasan, K. K.; Krishnan, S. R.

    2012-05-09

    Dual fuel pilot ignited natural gas engines are identified as an efficient and viable alternative to conventional diesel engines. This paper examines cyclic combustion fluctuations in conventional dual fuel and in dual fuel partially premixed low temperature combustion (LTC). Conventional dual fueling with 95% (energy basis) natural gas (NG) substitution reduces NOx emissions by almost 90%t relative to straight diesel operation; however, this is accompanied by 98% increase in HC emissions, 10 percentage points reduction in fuel conversion efficiency (FCE) and 12 percentage points increase in COVimep. Dual fuel LTC is achieved by injection of a small amount of diesel fuel (2-3 percent on an energy basis) to ignite a premixed natural gas�������¢����������������air mixture to attain very low NOx emissions (less than 0.2 g/kWh). Cyclic variations in both combustion modes were analyzed by observing the cyclic fluctuations in start of combustion (SOC), peak cylinder pressures (Pmax), combustion phasing (Ca50), and the separation between the diesel injection event and Ca50 (termed �������¢����������������relative combustion phasing�������¢���������������). For conventional dual fueling, as % NG increases, Pmax decreases, SOC and Ca50 are delayed, and cyclic variations increase. For dual fuel LTC, as diesel injection timing is advanced from 20���������������° to 60���������������°BTDC, the relative combustion phasing is identified as an important combustion parameter along with SoC, Pmax, and CaPmax. For both combustion modes, cyclic variations were characterized by alternating slow and fast burn cycles, especially at high %NG and advanced injection timings. Finally, heat release return maps were analyzed to demonstrate thermal management strategies as an effective tool to mitigate cyclic combustion variations, especially in dual fuel LTC.

  7. Fuel properties of eleven vegetable oils

    SciTech Connect

    Goering, C.E.; Daugherty, M.J.; Heakin, A.J.; Pryde, E.H.; Schwab, A.W.

    1982-11-01

    Eleven vegetable oils that can be grown as domestic field crops were identified for inclusion in a comparative study of chemical and fuel properties. Sample lots of each oil were subjected to ASTM tests appropriate for diesel fuels. The tests identified some problem areas with vegetable oil fuels. The oil samples were also characterized chemically and certain fuel properties were correlated to chemical compositions.

  8. Characterization of Melaleuca biomass as a fuel for direct combustion

    SciTech Connect

    Wang, S.; Huffman, J.B.; Littel, R.C.

    1981-01-01

    Selected properties of Melaleuca quinquenervia biomass were determined to evaluate its quality as a fuel. Ten trees were sampled from 2 areas (Lee and Dade Counties) in Florida. Test materials were sampled from: stem discs at 4 different heights; terminal branches; and foliage. Average heat values (cal/g) were 4400, 6160, 4610 and 4810 for wood and bark, terminal branches and foliage, respectively. Average densities (g/cubic centimeters) of wood and bark were 0.51 and 0.19 respectively. Average green m.c. was 114% for wood and 131% for bark, with maximum values of 178% and 265% respectively. Under the test conditions, average rate of moisture loss was 2.6% and 2.2% per day for wood samples in 3-cm cubes and 5-cm cubes, and 8.8% per day for 2X4X6-cm bark specimens (radial, tangential and longitudinal dimensions respectively).

  9. Propagation of a pulsating reaction front in solid fuel combustion

    Microsoft Academic Search

    B. J. Matkowsky; G. I. Sivashinsky

    1978-01-01

    We consider a system of reaction diffusion equations which describe gasless combustion of condensed systems. To analytically describe recent experimental results, we show that a solution exhibiting a periodically pulsating, propagating reaction front arises as a Hopf bifurication from a solution describing a uniformly propagating front. The bifurcation parameter is the product of a nondimensional activation energy and a factor

  10. Synthetic and jet fuels pyrolysis for cooling and combustion applications

    Microsoft Academic Search

    N. Gascoin; G. Abraham; P. Gillard

    2010-01-01

    Large heat load are encountered in hypersonic flight applications due to the high vehicle speed (over Mach 5, i.e. 5000kmh?1) and to the combustion heat release. If passive and ablative protections are a way to ensure the thermal management, the regenerative cooling is probably the most efficient one to enable the structures withstanding (notably for reusable structures). The present study

  11. Internal combustion engines fueled by natural gas—hydrogen mixtures

    Microsoft Academic Search

    S. Orhan Akansu; Zafer Dulger; Nafiz Kahraman; T. Nejat Veziro?lu

    2004-01-01

    In this study, a survey of research papers on utilization of natural gas–hydrogen mixtures in internal combustion engines is carried out. In general, HC, CO2, and CO emissions decrease with increasing H2, but NOx emissions generally increase. If a catalytic converter is used, NOx emission values can be decreased to extremely low levels. Consequently, equivalence zero emission vehicles (EZEV) standards

  12. Boiler combustion control system cuts fuel costs by 5%

    Microsoft Academic Search

    M. C. Benson; S. U. Moore

    1981-01-01

    Many companies have found improved boiler combustion control to be a cost effective means of gaining economic and environmental benefits in order to meet today's high energy costs and strict air quality standards. Minnesota Mining and Manufacturing Co. (3M) is an example of a firm which is sensitive to these concerns, and its facility in East St. Paul, Minnesota shows

  13. Internal combustion engines for alcohol motor fuels: a compilation of background technical information

    SciTech Connect

    Blaser, Richard

    1980-11-01

    This compilation, a draft training manual containing technical background information on internal combustion engines and alcohol motor fuel technologies, is presented in 3 parts. The first is a compilation of facts from the state of the art on internal combustion engine fuels and their characteristics and requisites and provides an overview of fuel sources, fuels technology and future projections for availability and alternatives. Part two compiles facts about alcohol chemistry, alcohol identification, production, and use, examines ethanol as spirit and as fuel, and provides an overview of modern evaluation of alcohols as motor fuels and of the characteristics of alcohol fuels. The final section compiles cross references on the handling and combustion of fuels for I.C. engines, presents basic evaluations of events leading to the use of alcohols as motor fuels, reviews current applications of alcohols as motor fuels, describes the formulation of alcohol fuels for engines and engine and fuel handling hardware modifications for using alcohol fuels, and introduces the multifuel engines concept. (LCL)

  14. The physical, chemical and combustion characteristics of EFB fuel briquettes

    NASA Astrophysics Data System (ADS)

    Rahman, Aizuddin Abdul; Sulaiman, Fauziah; Abdullah, Nurhayati

    2015-04-01

    The abundance of empty fruit bunches (EFB) from oil palm mill made them an economically attractive and viable source of energy nowadays. Converting pyrolyzed EFB into densified solid fuel (briquette) could overcome the troublesome of using raw material which has low energy density and lack of uniform properties for domestic and industrial energy utilization. In this work, EFB is pyrolyzed at 400°C under heating rate of 10°C/min for at least 2 hours to obtain char and pyrolysis liquid needed. Char is prepared as a main source for the briquette mixture, meanwhile the pyrolysis liquid acts as the binder. Both char and pyrolysis liquid were mixed at various percentage of concentrations; 90:10, 80:20, 70:30 and 60:40, and then manually compressed at 10MPa for at least 10 minutes. The results of the properties found that the proportion of 60:40 mixtures has the highest density value of approximately around 0.95 g/cm3, with largest weight loss of production up to 4.83%. The increased pyrolysis liquid added into the mixture has seemly lowered the energy value of the briquette from 23.13 to 21.23 MJ/kg. In the burning test determination, briquettes mixture of 70:30 was found to generate the highest temperature up to 483°C compared to others, and could retain a temperature of 100°C for at least 10 minutes after the flame was gradually put out by itself.

  15. Gas turbine combustion system utilizing renewable and non-critical solid fuels with residue removar to minimize environmental pollution

    SciTech Connect

    Marchand, W. C.

    1985-11-05

    Pressurized comminuted solid fuel particles are mechanically reground in a fuel injector prior to being radially injected in a swirling motion into a combustor where the fuel is mixed with oxidizing fluid in a swirling motion that is opposite to the swirling motion imparted to the solid fuel particles and burned to form both solid and gaseous products of combustion. The products of combustion are passed through an inertia separator where the solid products of combustion are removed by inertia. Means are also provided for injecting liquid or gaseous fuels into the combustor to assist in the combustion process and in meeting varying load demands on the engine.

  16. Observations on the combustion behavior of coal water fuels and coal water fuels impregnated with calcium magnesium acetate

    SciTech Connect

    Atal, A.; Levendis, Y.A. (Northeastern Univ., Boston, MA (United States))

    1993-04-01

    Combustion studies of single free-falling coal-water fuel (CWF) droplets were conducted in a drop-tube laminar-flow furnace at high heating rates. Most experiments were conducted with predried CWF agglomerates consisting of micronized (3.5 [mu]m mean size) and beneficiated bituminous coal. Agglomerates of known initial size, in the range of 100-600 [mu]m, were burned in air or pure oxygen at furnace temperatures between 1300 and 1500 K. Combustion of CWF agglomerates impregnated with calcium magnesium acetate (CMA), which is being considered as a sulfur capture agent, was also examined under the same conditions. Observations on the devolatilization and char combustion behavior of CWF agglomerates, formed after the evaporation of water, were conducted using pyrometric and cinematographic techniques. The char combustion is the most prominent since it accounts for 75%-85% of the burnout time. The volatile combustion phase is also important because of the resulting high-temperature radiant flames. Overall burnout times were between 150 and 600 ms, for the range of agglomerate sizes tested. Char combustion for most agglomerates was controlled by boundary layer diffusion of oxygen. The swelling behavior of the agglomerates was studied and swelling factors in the neighborhood of 1.12 were determined. Although the bituminous CWF, was found to swell and form cenospheric structures during heatup and devolatilization, the addition of CMA catalyst inhibited swelling of the agglomerates. However, the chars containing CMA exhibited occasional splitting or fragmentation during the volatile combustion stage.

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  18. Estimation of Fuel Savings by Recuperation of Furnace Exhausts to Preheat Combustion Air 

    E-print Network

    Rebello, W. J.; Kohnken, K. H.; Phipps, H. R., Jr.

    1980-01-01

    , it is necessary to be able to estimate the fuel saved by use of such a system. Standard industrial practice refers to the method described in the North American Combustion Handbook with its curves and tables that directly predict the percentage fuel savings...

  19. Air fuel ratio control apparatus and method for an internal combustion engine with a turbocharger

    SciTech Connect

    Sawamoto, K.; Ikeura, K.; Morita, T.; Yamaguchi, H.

    1984-05-29

    Normally, an air-fuel ratio is controlled in accordance with the engine speed and the intake air quantity of an internal combustion engine with a turbocharger. When the output pressure of the turbocharger increases excessively, an intake relief valve opens to decrease the intake air quantity. In this case, the fuel injection quantity is controlled solely in accordance with the engine speed.

  20. Combustion versus Fuel Cells: Consider the combination of hydrogen and oxygen

    E-print Network

    Combustion versus Fuel Cells: Consider the combination of hydrogen and oxygen H2 + 1 2 O2 - H2O substantially less work. 3.) If we do the process in a fuel cell, we use chemical availability from Gibbs cycle. The bottom line is that the recovery of the chemical energy as work is at best 117650 141780

  1. COMBUSTION OF A SOLID FUEL TUBE WITH CONTAINED LIQUID OXIDIZER IN A HOT GAS ATMOSPHERE

    Microsoft Academic Search

    A. D. PELOSI; A. GANY

    2007-01-01

    This work investigates the combustion behavior of a miniature configuration, which combines a solid fuel and a liquid oxidizer. A small diameter (about 1 mm) solid fuel tube is filled with a liquid oxidizer and embedded in a solid propellant strand. Two specific cases are studied experimentally: an aluminum tube filled with hydrogen peroxide and a polyethylene tube filled with nitric

  2. Fuel supply control method for internal combustion engines at low temperature

    Microsoft Academic Search

    H. Kano; T. Shinchi; S. Hosoi

    1987-01-01

    A method of controlling the quantity of fuel being supplied to an internal combustion engine in a cold state is described wherein a basic value of the quantity of fuel being supplied to the engine is corrected by the use of a first correction value which is set based upon a difference between a predetermined value and an actual value

  3. System and method for controlling fuel supply to an internal combustion engine

    Microsoft Academic Search

    T. Abo; T. Ueno

    1986-01-01

    This patent describes a system for controlling an amount of fuel supplied into an internal combustion engine having means for supplying the amount of fuel into the engine in response to a pulse signal inputted therein. It consists of: (a) a first means for calculating the actual quantity of air sucked into each engine cylinder on the basis of an

  4. GRH 12-01 Fireside Corrosion in Oxy-fuel Combustion Poster 0108

    SciTech Connect

    G. R. Holcomb; J. Tylczak; G. H. Meier; B. Lutz; K. Jung; N. Mu; N. M. Yanar; F. S. Pettit; J. Zhu; A. Wise; D. Laughlin; S. Sridhar

    2012-05-20

    The goals are to: (1) Achieve 90% CO{sub 2} capture at no more than a 35% increase in levelized cost of electricity of post-combustion capture for new and existing conventional coal-fired power plants; (2) Provide high-temperature corrosion information to aid in materials development and selection for oxy-fuel combustion; and (3) Identify corrosion mechanism and behavior differences between air- and oxy-firing.

  5. Combustion, performance and emission characteristics of a DI diesel engine fueled with ethanol–biodiesel blends

    Microsoft Academic Search

    Lei Zhu; C. S. Cheung; W. G. Zhang; Zhen Huang

    2011-01-01

    In this study, Euro V diesel fuel, biodiesel, and ethanol–biodiesel blends (BE) were tested in a 4-cylinder direct-injection diesel engine to investigate the combustion, performance and emission characteristics of the engine under five engine loads at the maximum torque engine speed of 1800rpm. The results indicate that when compared with biodiesel, the combustion characteristics of ethanol–biodiesel blends changed; the engine

  6. Effectiveness of combustion of shock-dispersed fuels in calorimeters of various volumes

    Microsoft Academic Search

    A. L. Kuhl; P. Neuwald; H. Reichenbach

    2006-01-01

    The combustion of a shock-dispersed-fuel charge consisting of 1-g flake Al in 6.6-, 21.5-, and 40.5-liter bomb calorimeters\\u000a were investigated. Wall pressure histories were used to diagnose the effect of energy release due to turbulent mixing and\\u000a combustion of the explosion cloud with air. These effects lead to a factor of four increase in the peak quasistatic pressure\\u000a for the

  7. Performance Evaluation of a High Bandwidth Liquid Fuel Modulation Valve for Active Combustion Control

    NASA Technical Reports Server (NTRS)

    Saus, Joseph R.; DeLaat, John C.; Chang, Clarence T.; Vrnak, Daniel R.

    2012-01-01

    At the NASA Glenn Research Center, a characterization rig was designed and constructed for the purpose of evaluating high bandwidth liquid fuel modulation devices to determine their suitability for active combustion control research. Incorporated into the rig s design are features that approximate conditions similar to those that would be encountered by a candidate device if it were installed on an actual combustion research rig. The characterized dynamic performance measures obtained through testing in the rig are planned to be accurate indicators of expected performance in an actual combustion testing environment. To evaluate how well the characterization rig predicts fuel modulator dynamic performance, characterization rig data was compared with performance data for a fuel modulator candidate when the candidate was in operation during combustion testing. Specifically, the nominal and off-nominal performance data for a magnetostrictive-actuated proportional fuel modulation valve is described. Valve performance data were collected with the characterization rig configured to emulate two different combustion rig fuel feed systems. Fuel mass flows and pressures, fuel feed line lengths, and fuel injector orifice size was approximated in the characterization rig. Valve performance data were also collected with the valve modulating the fuel into the two combustor rigs. Comparison of the predicted and actual valve performance data show that when the valve is operated near its design condition the characterization rig can appropriately predict the installed performance of the valve. Improvements to the characterization rig and accompanying modeling activities are underway to more accurately predict performance, especially for the devices under development to modulate fuel into the much smaller fuel injectors anticipated in future lean-burning low-emissions aircraft engine combustors.

  8. Co-combustion of solid recovered fuels in coal-fired power plants.

    PubMed

    Thiel, Stephanie; Thomé-Kozmiensky, Karl Joachim

    2012-04-01

    Currently, in ten coal-fired power plants in Germany solid recovered fuels from mixed municipal waste and production-specific commercial waste are co-combusted and experiments have been conducted at other locations. Overall, in 2010 approximately 800,000 tonnes of these solid recovered fuels were used. In the coming years up to 2014 a slight decline in the quantity of materials used in co-combustions is expected. The co-combustion activities are in part significantly influenced by increasing power supply from renewable sources of energy and their impact on the regime of coal-fired power plants usage. Moreover, price trends of CO? allowances, solid recovered fuels as well as imported coal also have significant influence. In addition to the usage of solid recovered fuels with biogenic content, the co-combustion of pure renewable biofuels has become more important in coal-fired power plants. The power plant operators make high demands on the quality of solid recovered fuels. As the operational experience shows, a set of problems may be posed by co-combustion. The key factors in process engineering are firing technique and corrosion. A significant ecological key factor is the emission of pollutants into the atmosphere. The results of this study derive from research made on the basis of an extensive literature search as well as a survey on power plant operators in Germany. The data from operators was updated in spring 2011. PMID:22143900

  9. Combustion Products of Petroleum Jet Fuel, a Fischer–Tropsch Synthetic Fuel, and a Biomass Fatty Acid Methyl Ester Fuel for a Gas Turbine Engine

    Microsoft Academic Search

    Michael T. Timko; Scott C. Herndon; Elena de la Rosa Blanco; Ezra C. Wood; Zhenhong Yu; Richard C. Miake-Lye; W. Berk Knighton; Linda Shafer; Matthew J. DeWitt; Edwin Corporan

    2011-01-01

    We report combustion emissions data for several alternatives to petroleum based Jet A jet fuel, including a natural gas–derived Fischer–Tropsch (FT) synthetic fuel; a 50\\/50 blend of the FT synthetic fuel with Jet A-1; a 20\\/80 blend of a fatty acid methyl ester (FAME) with jet fuel; and a 40\\/60 blend of FAME with jet fuel. The chief distinguishing features

  10. Aviation turbine fuel properties and their trends

    NASA Technical Reports Server (NTRS)

    Friedman, R.

    1981-01-01

    Fuel property values and their trends were studied through a review of a recognized, wide ranging sample population from actual fuel inspection data. A total of 676 fuel samples of Jet A aviation turbine fuel were compiled over an eleven year period. Results indicate that most fuel samples have one to three near-specification properties, the most common being aromatics, smoke point, and freezing point.

  11. Combustion engine having fuel cut-off at idle speed and compressed air starting and method of operation

    Microsoft Academic Search

    Slaughter

    1988-01-01

    This patent describes a non-idle method of operating an internal combustion engine including a rotary engine shaft; fuel supply means to supply fuel to the engine to cause the operation of the engine; an air compressor driven by rotation of the shaft and communicating with the engine to supply compressed air thereto for mixing with fuel to form a combustible

  12. Reduction of fuel side costs due to biomass co-combustion.

    PubMed

    Wils, Andrea; Calmano, Wolfgang; Dettmann, Peter; Kaltschmitt, Martin; Ecke, Holger

    2012-03-15

    The feasibility and influence of co-combustion of woody biomass on the fuel side costs is discussed for three hard coal power plants located in Berlin, Germany. Fuel side costs are defined as the costs resulting from flue gas cleaning and by-products. To have reliable data, co-firing tests were conducted in two power plants (i.e., slag tap furnace and circulating fluidising bed combustion). The amount of wood which was co-fired varied at levels below 11% of the fuel heat input. Wood chips originating from landscape management were used. The analyses show that co-combustion of woody biomass can lower the fuel side costs and that the co-combustion at a level below 10% of the thermal capacity is technically feasible without major problems. Furthermore, a flexible spreadsheet tool was developed for the calculation of fuel side costs and suggestions for operational improvements were made. For example, the adaptation of the Ca/S ratio (mass ratio of calcium in limestone to sulphur in the fuel) in one plant could reduce the fuel side costs up to 135 k€ yr(-1) (0.09 €M Wh(-1)). PMID:21514049

  13. Reduction of Volatile Organic Compounds (VOC) emission from fossil fuel combustion by catalytic treatment of flue gases

    Microsoft Academic Search

    L. Bonfanti; F. Mirabella; M. Cioni; M. Mazzanti; S. Malloggi

    Volatile Organic Compounds (VOC) emissions from industrial combustion plants can include compounds that will probably be subjected to more and more stringent regulation in the near future. Both new fuels and advanced combustion technologies used for energy generation, in spite of the advantage they can offer for increasing combustion efficiency and minimizing some conventional pollutants or relatively heavy organic micro-pollutants,

  14. Development of high temperature air combustion technology in pulverized fossil fuel fired boilers

    SciTech Connect

    Hai Zhang; Guangxi Yue; Junfu Lu; Zhen Jia; Jiangxiong Mao; Toshiro Fujimori; Toshiyuki Suko; Takashi Kiga [Tsinghua University, Beijing (China). Department of Thermal Engineering

    2007-07-01

    High temperature air combustion (HTAC) is a promising technology for energy saving, flame stability enhancement and NOx emission reduction. In a conventional HTAC system, the combustion air is highly preheated by using the recuperative or regenerative heat exchangers. However, such a preheating process is difficult to implement for pulverized fossil fuel fired boilers. In this paper, an alternative approach is proposed. In the proposed HTAC system, a special burner, named PRP burner is introduced to fulfill the preheating process. The PRP burner has a preheating chamber with one end connected with the primary air and the other end opened to the furnace. Inside the chamber, gas recirculation is effectively established such that hot flue gases in the furnace can be introduced. Combustible mixture instead of combustion air is highly preheated by the PRP burner. A series of experiments have been conducted in an industrial scale test facility, burning low volatile petroleum coke and an anthracite coal. Stable combustion was established for burning pure petroleum coke and anthracite coal, respectively. Inside the preheating chamber, the combustible mixture was rapidly heated up to a high temperature level close to that of the hot secondary air used in the conventional HTAC system. The rapid heating of the combustible mixture in the chamber facilitates pyrolysis, volatile matter release processes for the fuel particles, suppressing ignition delay and enhancing combustion stability. Moreover, compared with the results measured in the same facility but with a conventional low NOx burner, NOx concentration at the furnace exit was at the same level when petroleum coke was burnt and 50% less when anthracite was burnt. Practicability of the HTAC technology using the proposed approach was confirmed for efficiently and cleanly burning fossil fuels. 16 refs., 10 figs., 1 tab.

  15. The origin of organic pollutants from the combustion of alternative fuels: Phase 5/6 report

    SciTech Connect

    Sidhu, S.; Graham, J.; Taylor, P.; Dellinger, B. [Univ. of Dayton, OH (United States). Research Inst.

    1998-05-01

    As part of the US Department of Energy National Renewable Energy Laboratory program on alternative automotive fuels, the subcontractor has been conducting studies on the origin and fate of organic pollutants from the combustion of alternative fuels. Laboratory experiments were conducted simulating cold start of four alterative fuels (compressed natural gas, liquefied petroleum gas, methanol-gasoline mix, and ethanol-gasoline mix) using a commercial three-way catalyst under fuel-lean conditions. This report summarizes the results of these experiments. It appears that temperature of the catalyst is a more important parameter for fuel conversion and pollutant formation than oxygen concentration or fuel composition.

  16. MUNICIPAL WASTE COMBUSTION ASSESSMENT: FOSSIL FUEL CO-FIRING

    EPA Science Inventory

    The report identifies refuse derived fuel (RDF) processing operations and various RDF types; describes such fossil fuel co-firing techniques as coal fired spreader stokers, pulverized coal wall fired boilers, pulverized coal tangentially fired boilers, and cyclone fired boilers; ...

  17. Apparatus and method for operating internal combustion engines from variable mixtures of gaseous fuels

    DOEpatents

    Heffel, James W.; Scott, Paul B.; Park, Chan Seung

    2011-11-01

    An apparatus and method for utilizing any arbitrary mixture ratio of multiple fuel gases having differing combustion characteristics, such as natural gas and hydrogen gas, within an internal combustion engine. The gaseous fuel composition ratio is first sensed, such as by thermal conductivity, infrared signature, sound propagation speed, or equivalent mixture differentiation mechanisms and combinations thereof which are utilized as input(s) to a "multiple map" engine control module which modulates selected operating parameters of the engine, such as fuel injection and ignition timing, in response to the proportions of fuel gases available so that the engine operates correctly and at high efficiency irrespective of the gas mixture ratio being utilized. As a result, an engine configured according to the teachings of the present invention may be fueled from at least two different fuel sources without admixing constraints.

  18. Apparatus and method for operating internal combustion engines from variable mixtures of gaseous fuels

    DOEpatents

    Heffel, James W.; Scott, Paul B.

    2003-09-02

    An apparatus and method for utilizing any arbitrary mixture ratio of multiple fuel gases having differing combustion characteristics, such as natural gas and hydrogen gas, within an internal combustion engine. The gaseous fuel composition ratio is first sensed, such as by thermal conductivity, infrared signature, sound propagation speed, or equivalent mixture differentiation mechanisms and combinations thereof which are utilized as input(s) to a "multiple map" engine control module which modulates selected operating parameters of the engine, such as fuel injection and ignition timing, in response to the proportions of fuel gases available so that the engine operates correctly and at high efficiency irrespective of the gas mixture ratio being utilized. As a result, an engine configured according to the teachings of the present invention may be fueled from at least two different fuel sources without admixing constraints.

  19. Multiphase CFD-based models for chemical looping combustion process: Fuel reactor modeling

    SciTech Connect

    Jung, Jonghwun (ANL); Gamwo, I.K.

    2008-04-21

    Chemical looping combustion (CLC) is a flameless two-step fuel combustion that produces a pure CO2 stream, ready for compression and sequestration. The process is composed of two interconnected fluidized bed reactors. The air reactor which is a conventional circulating fluidized bed and the fuel reactor which is a bubbling fluidized bed. The basic principle is to avoid the direct contact of air and fuel during the combustion by introducing a highly-reactive metal particle, referred to as oxygen carrier, to transport oxygen from the air to the fuel. In the process, the products from combustion are kept separated from the rest of the flue gases namely nitrogen and excess oxygen. This process eliminates the energy intensive step to separate the CO2 from nitrogen-rich flue gas that reduce the thermal efficiency. Fundamental knowledge of multiphase reactive fluid dynamic behavior of the gas–solid flow is essential for the optimization and operation of a chemical looping combustor. Our recent thorough literature review shows that multiphase CFD-based models have not been adapted to chemical looping combustion processes in the open literature. In this study, we have developed the reaction kinetics model of the fuel reactor and implemented the kinetic model into a multiphase hydrodynamic model, MFIX, developed earlier at the National Energy Technology Laboratory. Simulated fuel reactor flows revealed high weight fraction of unburned methane fuel in the flue gas along with CO2 and H2O. This behavior implies high fuel loss at the exit of the reactor and indicates the necessity to increase the residence time, say by decreasing the fuel flow rate, or to recirculate the unburned methane after condensing and removing CO2.

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

    PubMed

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

    2003-01-01

    In order to predict and improve the performance of natural gas/diesel dual fuel engine (DFE), a combustion rate model based on forward neural network was built to study the combustion process of the DFE. The effect of the operating parameters on combustion rate was also studied by means of this model. The study showed that the predicted results were good agreement with the experimental data. It was proved that the developed combustion rate model could be used to successfully predict and optimize the combustion process of dual fuel engine. PMID:12659230

  1. ORGANIC COMBUSTION FINGERPRINTS OF THREE COMMON HOME HEATING FUELS

    EPA Science Inventory

    The paper discusses the chemical structures of three common home eating fuels: wood, coal, and No. 2 fuel oil. GC and GC/MS data are then presented which demonstrate how the thermal destruction of each fuel results in the production of a characteristic group of organic "fingerpri...

  2. Performance Comparison of Hydrogen Fuel Cell and Hydrogen Internal Combustion Engine Racing Cars

    Microsoft Academic Search

    G. Pearson; M. Leary; A. Subic; J. Wellnitz

    \\u000a Students from RMIT University and the University of Applied Sciences Ingolstadt have collaborated to build a hydrogen-powered\\u000a racing car. As part of the initial conceptual design, a lap simulation was developed to compare performance and fuel usage\\u000a of hydrogen internal combustion engine and hydrogen fuel cell vehicles. For the vehicle and track specifications analyzed,\\u000a it was found that fuel cells

  3. Design strategy for the combustion of coal-derived liquid fuels

    Microsoft Academic Search

    J. M. Beer; M. T. Jacques; W. F. Farmayan; J. D. Teare

    1982-01-01

    Results are reported of experiments on the amenability of SRC-II coal-derived liquid fuels to combustion process modification by air staging for NO\\/sub x\\/ and particulates emission control. Two experimental systems were used: (1) a laboratory laminar flow reactor for determining rates of evolution of fuel-bound nitrogen from pyrolyzing arrays of 150 ..mu..m SRC-II fuel droplets; and (2) a pilot plant

  4. Combustion synthesis and effects of processing parameters on physical properties of {alpha}-alumina

    SciTech Connect

    Collins, M.V.; Hirschfeld, D.A.; Shea, L.E.

    2000-01-04

    Fine particle porous {alpha}-alumina has been prepared by a wet chemical method of combustion synthesis using an aqueous precursor containing aluminum nitrate (oxidizer) and carbohydrazide, an organic fuel as starting materials. The aluminum nitrate and carbohydrazide were reacted exothermically at 400--600 C. The synthesis of {alpha}-alumina ({alpha}-Al{sub 2}O{sub 3}) was used as a model for understanding the effects of processing parameters on physical properties such as surface area, average pore size, and residual carbon content. The porous powders were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), BET surface area analysis and elemental analysis. The decomposition of the starting materials was investigated using differential thermal and thermogravimetric analyses (DTA/TGA). It has been shown that the furnace temperature, fuel/oxidizer ratio, and precursor water content can be tailored to produce powders with different physical properties.

  5. Sulfur emission from Victorian brown coal under pyrolysis, oxy-fuel combustion and gasification conditions.

    PubMed

    Chen, Luguang; Bhattacharya, Sankar

    2013-02-01

    Sulfur emission from a Victorian brown coal was quantitatively determined through controlled experiments in a continuously fed drop-tube furnace under three different atmospheres: pyrolysis, oxy-fuel combustion, and carbon dioxide gasification conditions. The species measured were H(2)S, SO(2), COS, CS(2), and more importantly SO(3). The temperature (873-1273 K) and gas environment effects on the sulfur species emission were investigated. The effect of residence time on the emission of those species was also assessed under oxy-fuel condition. The emission of the sulfur species depended on the reaction environment. H(2)S, SO(2), and CS(2) are the major species during pyrolysis, oxy-fuel, and gasification. Up to 10% of coal sulfur was found to be converted to SO(3) under oxy-fuel combustion, whereas SO(3) was undetectable during pyrolysis and gasification. The trend of the experimental results was qualitatively matched by thermodynamic predictions. The residence time had little effect on the release of those species. The release of sulfur oxides, in particular both SO(2) and SO(3), is considerably high during oxy-fuel combustion even though the sulfur content in Morwell coal is only 0.80%. Therefore, for Morwell coal utilization during oxy-fuel combustion, additional sulfur removal, or polishing systems will be required in order to avoid corrosion in the boiler and in the CO(2) separation units of the CO(2) capture systems. PMID:23301852

  6. Effects of super heating of heavy fuels on combustion and performance in DI diesel engines

    SciTech Connect

    Murayama, T.; Oh, Y.; Kido, A.; Chikahisa, T.; Itow, K.

    1986-01-01

    This paper is concerned with the effects of temperature of heavy fuels on combustion and engine performance in a naturally aspirated DI diesel engine. Engine performance and exhaust gas emissions were measured for rapeseed oil, B-heavy oil, and diesel fuel at fuel temperatures from 40/sup 0/C to 400/sup 0/C. With increased fuel temperature, mainly from improved efficiency of combustion there were significant reductions in the specific energy consumption and smoke emissions. It was found that the improvements were mainly a function of the fuel viscosity, and it was independent of the kind of fuel. The optimum temperature of the fuels with regard to specific energy consumption and smoke emission is about 90/sup 0/C for diesel fuel, 240/sup 0/C for B-heavy oil, and 300/sup 0/C for rapeseed oil. At these temperatures, the viscosities of the fuels show nearly identical value, 0.9 - 3 cSt. The optimum viscosity tends to increase slightly with increases in the swirl ratio in the combustion chamber.

  7. Dynamics of hot spots in solid fuel combustion

    NASA Astrophysics Data System (ADS)

    Bayliss, A.; Matkowsky, B. J.; Aldushin, A. P.

    2002-06-01

    We consider the gasless combustion model of the SHS (self-propagating high temperature synthesis) process in which combustion waves are employed to synthesize desired materials. Specifically, we consider the combustion of a solid sample in which combustion occurs on the surface of a cylinder of radius R. We consider solution behavior as R is increased. This parameter is important for technological applications, as it is often desirable to synthesize large samples of the desired product. For the fixed value of the Zeldovich number considered, if R is sufficiently small, slowly propagating planar pulsating flames are the only modes observed. As R is increased transitions to more complex modes of combustion occur, including: (i) traveling waves (TWs), i.e., spin modes in which one or several symmetrically spaced hot spots rotate around the cylinder as the flame propagates along the cylindrical axis, thus following a helical path, (ii) counterpropagating (CP) modes, in which spots propagate in opposite angular directions around the cylinder, executing various types of dynamics, (iii) alternating spin CP (ASCP) modes, where rotation of a spot around the cylinder is interrupted by periodic events in which a new spot is spontaneously created ahead of the rotating spot. The new spot splits into CP daughter spots, one of which collides with the original spot leading to their eventual mutual annihilation, while the other continues to spin, (iv) modulated traveling waves (MTWs) consisting of either one or two symmetrically located rotating spots which exhibit a periodic modulation in speed and temperature as they rotate, (v) asymmetric traveling waves (ATWs) in which two spots of unequal strength and not separated by angle ?, rotate together as a bound state, (vi) modulated asymmetric traveling waves (MATWs) in which the two asymmetric spots oscillate in a periodic manner as they rotate, alternately approaching each other and then moving apart periodically in time, (vii) asymmetric ASCP (AASCP) modes in which a slowly varying bound state of two spots rotates around the cylinder with the leading spot, and subsequently the trailing spot, exhibiting episodes of ASCP behavior, and (viii) 3-headed spins in which three spots rotate around the cylinder in a nonuniform fashion so that each cell alternately approaches one of its neighbors and then the other. In one case, referred to as MTW3, the motion is apparently quasiperiodic, with neighboring spots approaching and departing from each other periodically in time as they rotate. In another case, referred to as C3, the motion is apparently chaotic. Two neighboring spots nearly collide, after which one spot is rapidly propelled away from the other as they rotate. Finally, for a slightly higher value of R, two neighboring spots collide, leading to annihilation of one spot and collapse of the 3-headed spin to a 2-headed spin mode.

  8. Active suppression of vortex-driven combustion instability using controlled liquid-fuel injection

    NASA Astrophysics Data System (ADS)

    Pang, Bin

    Combustion instabilities remain one of the most challenging problems encountered in developing propulsion and power systems. Large amplitude pressure oscillations, driven by unsteady heat release, can produce numerous detrimental effects. Most previous active control studies utilized gaseous fuels to suppress combustion instabilities. However, using liquid fuel to suppress combustion instabilities is more realistic for propulsion applications. Active instability suppression in vortex-driven combustors using a direct liquid fuel injection strategy was theoretically established and experimentally demonstrated in this dissertation work. Droplet size measurements revealed that with pulsed fuel injection management, fuel droplet size could be modulated periodically. Consequently, desired heat release fluctuation could be created. If this oscillatory heat release is coupled with the natural pressure oscillation in an out of phase manner, combustion instabilities can be suppressed. To identify proper locations of supplying additional liquid fuel for the purpose of achieving control, the natural heat release pattern in a vortex-driven combustor was characterized in this study. It was found that at high Damkohler number oscillatory heat release pattern closely followed the evolving vortex front. However, when Damkohler number became close to unity, heat release fluctuation wave no longer coincided with the coherent structures. A heat release deficit area was found near the dump plane when combustor was operated in lean premixed conditions. Active combustion instability suppression experiments were performed in a dump combustor using a controlled liquid fuel injection strategy. High-speed Schlieren results illustrated that vortex shedding plays an important role in maintaining self-sustained combustion instabilities. Complete combustion instability control requires total suppression of these large-scale coherent structures. The sound pressure level at the excited dominant frequency was reduced by more than 20 dB with controlled liquid fuel injection method. Scaling issues were also investigated in this dump combustor to test the effectiveness of using pulsed liquid fuel injection strategies to suppress instabilities at higher power output conditions. With the liquid fuel injection control method, it was possible to suppress strong instabilities with initial amplitude of +/-5 psi down to the background noise level. The stable combustor operating range was also expanded from equivalence ratio of 0.75 to beyond 0.9.

  9. Combustion of hydrogen in a two-dimensional duct with step fuel injectors

    NASA Technical Reports Server (NTRS)

    Eggers, J. M.; Reagon, P. G.; Gooderum, P. B.

    1978-01-01

    An investigation of the combustion of hydrogen perpendicularly injected from step fuel injectors into a Mach 2.72, 2100 K vitiated test gas was conducted. The model simulated the flow between the center and side struts of an integrated scramjet module at Mach 7 flight and an altitude of 29 km. Parametric variation included equivalence ratio, fuel dynamic pressure ratio, and area distribution of the model. The overall area ratio of the model was held constant at 2.87. The data analysis indicated that no measurable improvement in mixing or combustion efficiency was obtained by varying the fuel dynamic pressure ratio from 0.79 to 2.45. Computations indicated approximately 80 percent of the fuel was mixed so that it could react; however, only approximately 50 percent of the mixed fuel actually reacted in two test configurations, and 74 percent in later tests where less area expansion of the flow occurred.

  10. Utilization of spent activated carbon to enhance the combustion efficiency of organic sludge derived fuel.

    PubMed

    Chen, Wei-Sheng; Lin, Chang-Wen; Chang, Fang-Chih; Lee, Wen-Jhy; Wu, Jhong-Lin

    2012-06-01

    This study examines the heating value and combustion efficiency of organic sludge derived fuel, spent activated carbon derived fuel, and derived fuel from a mixture of organic sludge and spent activated carbon. Spent activated carbon was sampled from an air pollution control device of an incinerator and characterized by XRD, XRF, TG/DTA, and SEM. The spent activated carbon was washed with deionized water and solvent (1N sulfuric acid) and then processed by the organic sludge derived fuel manufacturing process. After washing, the salt (chloride) and sulfide content could be reduced to 99% and 97%, respectively; in addition the carbon content and heating value were increased. Different ratios of spent activated carbon have been applied to the organic sludge derived fuel to reduce the NO(x) emission of the combustion. PMID:22209404

  11. Combustion behaviors of a compression-ignition engine fueled with diesel/methanol blends under various fuel delivery advance angles.

    PubMed

    Huang, Zuohua; Lu, Hongbing; Jiang, Deming; Zeng, Ke; Liu, Bing; Zhang, Junqiang; Wang, Xibin

    2004-12-01

    A stabilized diesel/methanol blend was described and the basic combustion behaviors based on the cylinder pressure analysis was conducted in a compression-ignition engine. The study showed that increasing methanol mass fraction of the diesel/methanol blends would increase the heat release rate in the premixed burning phase and shorten the combustion duration of the diffusive burning phase. The ignition delay increased with the advancing of the fuel delivery advance angle for both the diesel fuel and the diesel/methanol blends. For a specific fuel delivery advance angle, the ignition delay increased with the increase of the methanol mass fraction (oxygen mass fraction) in the fuel blends and the behaviors were more obvious at low engine load and/or high engine speed. The rapid burn duration and the total combustion duration increased with the advancing of the fuel delivery advance angle. The centre of the heat release curve was close to the top-dead-centre with the advancing of the fuel delivery advance angle. Maximum cylinder gas pressure increased with the advancing of the fuel delivery advance angle, and the maximum cylinder gas pressure of the diesel/methanol blends gave a higher value than that of the diesel fuel. The maximum mean gas temperature remained almost unchanged or had a slight increase with the advancing of the fuel delivery advance angle, and it only slightly increased for the diesel/methanol blends compared to that of the diesel fuel. The maximum rate of pressure rise and the maximum rate of heat release increased with the advancing of the fuel delivery advance angle of the diesel/methanol blends and the value was highest for the diesel/methanol blends. PMID:15288277

  12. Detailed Chemical Kinetic Modeling of Diesel Combustion with Oxygenated Fuels

    Microsoft Academic Search

    H J Curran; E M Fisher; P-A Glaude; N M Marinov; W J Pitz; C K Westbrook; P F Flynn; R P Durrett; A O zur Loye; O C Akinyemi; F L Dryer

    2000-01-01

    Emission standards for diesel engines in vehicles have been steadily reduced in recent years, and a great deal of research and development effort has been focused on reducing particulate and nitrogen oxide emissions. One promising approach to reducing emissions involves the addition of oxygen to the fuel, generally by adding an oxygenated compound to the normal diesel fuel. Miyamoto et

  13. Efficient combustion of fuels with controlled chemical underburning

    NASA Astrophysics Data System (ADS)

    Roslyakov, P. V.; Ionkin, I. L.; Pleshanov, K. A.

    2009-01-01

    We present results obtained from putting into use a method of firing natural gas and fuel oil with controlled chemical underburning that allows nitrogen oxide emissions to be reduced by 20-40% in boilers that are in operation. The permissible level of fuel underburning from the considerations of ensuring efficient and environmentally safe operating conditions is determined.

  14. Flame blowout and pollutant emissions in vitiated combustion of conventional and bio-derived fuels

    NASA Astrophysics Data System (ADS)

    Singh, Bhupinder

    The widening gap between the demand and supply of fossil fuels has catalyzed the exploration of alternative sources of energy. Interest in the power, water extraction and refrigeration (PoWER) cycle, proposed by the University of Florida, as well as the desirability of using biofuels in distributed generation systems, has motivated the exploration of biofuel vitiated combustion. The PoWER cycle is a novel engine cycle concept that utilizes vitiation of the air stream with externally-cooled recirculated exhaust gases at an intermediate pressure in a semi-closed cycle (SCC) loop, lowering the overall temperature of combustion. It has several advantages including fuel flexibility, reduced air flow, lower flame temperature, compactness, high efficiency at full and part load, and low emissions. Since the core engine air stream is vitiated with the externally cooled exhaust gas recirculation (EGR) stream, there is an inherent reduction in the combustion stability for a PoWER engine. The effect of EGR flow and temperature on combustion blowout stability and emissions during vitiated biofuel combustion has been characterized. The vitiated combustion performance of biofuels methyl butanoate, dimethyl ether, and ethanol have been compared with n-heptane, and varying compositions of syngas with methane fuel. In addition, at high levels of EGR a sharp reduction in the flame luminosity has been observed in our experimental tests, indicating the onset of flameless combustion. This drop in luminosity may be a result of inhibition of processes leading to the formation of radiative soot particles. One of the objectives of this study is finding the effect of EGR on soot formation, with the ultimate objective of being able to predict the boundaries of flameless combustion. Detailed chemical kinetic simulations were performed using a constant-pressure continuously stirred tank reactor (CSTR) network model developed using the Cantera combustion code, implemented in C++. Results have been presented showing comparative trends in pollutant emissions generation, flame blowout stability, and combustion efficiency. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)

  15. Combustion space modelling of oxy-fuel fired glass melter

    SciTech Connect

    Richter, W. (Richter (Wolfgang), Irvine, CA (USA)); Kobayashi, Hisashi (Union Carbide Industrial Gases, Inc., Tarrytown, NY (USA))

    1990-01-01

    A three-dimensional heat transfer code based on the zonal method was applied to evaluate the oxygen-fuel firing of a cross-fired regenerative glass melter. A furnace end section which includes the bridge wall and a pair of the regenerator ports was modelled in detail for a base air case and several oxy-fuel firing cases. The firing rates of two oxy-fuel burners that matched the heat flux distribution of the base air case were determined. The effects of the height and angle of the oxy-fuel burners on the temperature and heat flux distributions were predicted to evaluate the optimum burner placement of the oxy-fuel burners. The main conclusions of the simulation are that; (1) in spite of the small flame diameters, the high momentum low flame temperature oxy-fuel burners can create temperature and heat flux distributions equivalent to those of the base air case with a wide flame and (2) both lower burner elevation and angling of the oxy-fuel burners toward the glass surface tend to increase heat transfer to glass surface and reduce the peak refractory temperatures. 12 refs., 21 figs., 4 tabs.

  16. Determination of alternative fuels combustion products: Phase 3 report

    SciTech Connect

    Whitney, K.A. [Southwest Research Inst., San Antonio, TX (United States)

    1997-12-01

    This report describes the laboratory efforts to characterize particulate and gaseous exhaust emissions from a passenger vehicle operating on alternative fuels. Tests were conducted at room temperature (nominally 72 F) and 20 F utilizing the chassis dynamometer portion of the FTP for light-duty vehicles. Fuels evaluated include Federal RFG, LPG meeting HD-5 specifications, a national average blend of CNG, E85, and M85. Exhaust particulate generated at room temperature was further characterized to determine polynuclear aromatic content, trace element content, and trace organic constituents. For all fuels except M85, the room temperature particulate emission rate from this vehicle was about 2 to 3 mg/mile. On M85, the particulate emission rate was more than 6 mg/mile. In addition, elemental analysis of particulate revealed an order of magnitude more sulfur and calcium from M85 than any other fuel. The sulfur and calcium indicate that these higher emissions might be due to engine lubricating oil in the exhaust. For RFG, particulate emissions at 20 F were more than six times higher than at room temperature. For alcohol fuels, particulate emissions at 20 F were two to three times higher than at room temperature. For CNG and LPG, particulate emissions were virtually the same at 72 F and 20 F. However, PAH emissions from CNG and LPG were higher than expected. Both gaseous fuels had larger amounts of pyrene, 1-nitropyrene, and benzo(g,h,i)perylene in their emissions than the other fuels.

  17. Further investigation of the impact of the co-combustion of tire-derived fuel and petroleum coke on the petrology and chemistry of coal combustion products

    SciTech Connect

    Hower, J.C.; Robertson, J.D.; Elswick, E.R.; Roberts, J.M.; Brandsteder, K.; Trimble, A.S.; Mardon, S.M. [University of Kentucky, Lexington, KY (United States). Center for Applied Energy Research

    2007-07-01

    A Kentucky cyclone-fired unit burns coal and tire-derived fuel, sometimes in combination with petroleum coke. A parallel pulverized combustion (pc) unit at the same plant burns the same coal, without the added fuels. The petrology, chemistry, and sulfur isotope distribution in the fuel and resulting combustion products was investigated for several configurations of the fuel blend. Zinc and Cd in the combustion products are primarily contributed from the tire-derived fuel, the V and Ni are primarily from the petroleum coke, and the As and Hg are probably largely from the coal. The sulfur isotope distribution in the cyclone unit is complicated due to the varying fuel sources. The electrostatic precipitator (ESP) array in the pc unit shows a subtle trend towards heavier S isotopic ratios in the cooler end of the ESP.

  18. Gas turbine combustion system utilizing renewable and non-critical solid fuels with residue remover to minimize environmental pollution

    SciTech Connect

    Marchand, W.C.

    1982-07-13

    Pressurized communited solid fuel particles are mechanically reground in a fuel injector prior to being radially injected in a swirling motion into a combustor where the fuel is mixed with oxidizing fluid in a swirling motion that is opposite to the swirling motion imported to the solid fuel particles and burned to form both solid and gaseous products of combustion. The products of combustion are passed through separator where the solid products of combustor are removed by inertia. Means are also provided for injecting liquid or gaseous fuels into the combustor to assist in the combustion process and meeting varying load demands on the engine.

  19. Combustion studies of coal-derived solid fuels. Part IV. Correlation of ignition temperatures from thermogravimetry and free-floating experiments

    USGS Publications Warehouse

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1992-01-01

    The usefulness of TG as an efficient and practical method to characterize the combustion properties of fuels used in large-scale combustors is of considerable interest. Relative ignition temperatures of a lignite, an anthracite, a bituminous coal and three chars derived from this coal were measured by a free-floating technique. These temperatures were correlated with those estimated from TG burning profiles of the fuels. ?? 1992.

  20. Combustion performance test of a new fuel DME to adapt to a gas turbine for power generation

    Microsoft Academic Search

    Min Chul Lee; Seok Bin Seo; Jae Hwa Chung; Yong Jin Joo; Dal Hong Ahn

    2008-01-01

    Recently, DME (dimethyl ether, CH3OCH3) has attracted a great deal of attention as an alternative fuel owing to its easy transportation and cleanliness. This study was conducted to verify the combustion performance and to identify potential problems when DME is fueled to a gas turbine. Combustion tests were conducted by comparing DME with methane, which is a major component of

  1. Performance, Efficiency, and Emissions Characterization of Reciprocating Internal Combustion Engines Fueled with Hydrogen\\/Natural Gas Blends

    Microsoft Academic Search

    Kirby S. Chapman; Amar Patil

    2007-01-01

    Hydrogen is an attractive fuel source not only because it is abundant and renewable but also because it produces almost zero regulated emissions. Internal combustion engines fueled by compressed natural gas (CNG) are operated throughout a variety of industries in a number of mobile and stationary applications. While CNG engines offer many advantages over conventional gasoline and diesel combustion engines,

  2. Modeling the Feasibility of Using Fuel Cells and Hydrogen Internal Combustion Engines in Remote Renewable Energy Systems: Preprint

    Microsoft Academic Search

    J. Cotrell; W. Pratt

    2003-01-01

    Recent advances in hydrogen fuel cell and internal combustion engine technologies have enabled new energy options for supplying electrical power in remote, off-grid areas. The objective of this investigation is to determine under which conditions wind turbines and PV systems can feasibly power electrolyzers to generate and store hydrogen for remote power generation using fuel cells and internal combustion engines.

  3. Combustion characteristics of intake port injection type hydrogen fueled engine

    Microsoft Academic Search

    S. J. Lee; H. S. Yi; E. S. Kim

    1995-01-01

    This paper describes the experimental results on a hydrogen fueled single cylinder engine to study the characteristics of a solenoid-driven intake port injection type hydrogen injection valve. In experiments, the fuel-air equivalence ratio was varied from the lean limit at which stable operation was guaranteed to the rich limit at which flash-back occurred and spark timing was also changed. As

  4. Domestic biomass fuel combustion and chronic bronchitis in two rural Bolivian villages

    Microsoft Academic Search

    R Albalak; A R Frisancho; G J Keeler

    1999-01-01

    BACKGROUNDChronic bronchitis is an important public health problem worldwide. A study was undertaken to examine the association between exposure to air pollution from domestic biomass fuel combustion and chronic bronchitis in two rural Bolivian highland villages: a village in which cooking is done exclusively indoors and a village in which cooking is done primarily outdoors. Apart from this difference, the

  5. Ignition and combustion of liquid fuel droplet in a convective medium

    Microsoft Academic Search

    S. K. Dash; S. K. Som

    1991-01-01

    This paper reports that an mathematical model of droplet combustion in surroundings of hot gas with a uniform free stream motion is made from the numerical solution of the conservation equations of heat, mass and momentum in both the carrier and droplet phases. The gas phase chemical reaction between fuel vapor and oxidizer is assumed to be a single-step irreversible

  6. A synthesis of carbon dioxide emissions from fossil-fuel combustion

    Microsoft Academic Search

    Robert Joseph Andres; Thomas A Boden; F.-M. Breon; P. Ciais; S. Davis; D Erickson; J. S. Gregg; Andrew Jacobson; Gregg Marland; J. Miller; T Oda; J. G. J. Oliver; Michael Raupach; P Rayner; K. Treanton

    2012-01-01

    This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores 5 our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts

  7. RECENT DEVELOPMENTS OF EMISSION CONTROL TECHNOLOGY IN THE UNITED STATES FOR FOSSIL FUEL COMBUSTION SOURCES

    EPA Science Inventory

    The paper discusses control of air pollution from fossil fuel combustion. ntil recently, this meant abatement of smoke (particulate), sulfur dioxide, and oxides of nitrogen. With growing concern about global climate change, carbon dioxide has been added to the list. The paper inc...

  8. QUANTIFYING HAZARDOUS SPECIES IN PARTICULATE MATTER DERIVED FROM FOSSIL-FUEL COMBUSTION

    EPA Science Inventory

    An analysis protocol that combines X-ray absorption near-edge structure spectroscopy with selective leaching has been developed to examine hazardous species in size- segregated particulate matter (PM) samples derived from the combustion of fossil fuels. The protocol has been used...

  9. Apparatus for controlling the supply of fuel to an internal combustion engine

    Microsoft Academic Search

    A. Yasuoka; T. Kiuchi

    1987-01-01

    This patent describes an apparatus for controlling the supply of fuel to an internal combustion engine having a control valve means for controlling the amount of air to be supplied to an engine piston downstream of a throttle valve. The improvement described here comprises: means for detecting any disorder in the amount of air and outputting a disorder indicating signal;

  10. Health effects of fossil fuel combustion products: report of a workshop.

    PubMed Central

    Comar, C L; Nelson, N

    1975-01-01

    Judgemental positions are presented on research priorities in regard to the health effects from stationary sources of fossil fuel combustion products. Hopefully, they can provide guidance for efforts to ensure that national energy needs are met with minimum environmental and economic burdens on the public. The major areas include epidemiological studies, controlled biological studies, mutagenesis and carcinogenesis, trace elements, monitoring and analysis. PMID:1227856

  11. Theoretical Combustion Performance of Several High-Energy Fuels for Ramjet Engines

    NASA Technical Reports Server (NTRS)

    Tower, Leonard K; Breitwieser, Roland; Gammon, Benson E

    1958-01-01

    An analytical evaluation of the air and fuel specific-impulse characteristics of magnesium, magnesium octene-1 slurries, aluminum, aluminum octene-1 slurries, boron, boron octene-1 slurries, carbon, hydrogen, alpha-methylnaphthalene, diborane, pentaborane, and octene-1 is presented. While chemical equilibrium was assumed in the combustion process, the expansion was assumed to occur at fixed composition.

  12. Combustion Control in a Fuel Oil Boiler from the Flame Spectrum

    Microsoft Academic Search

    O. FARIAS

    A new concept of combustion control system, based on an optical information from the flame spectrum, is applied to a domestic fuel oil boiler. The objective is to achieve the maximum thermal efficiency of the boiler, while keeping a stable flame and the pollutant emissions as low as possible. CH radicals and soot continuum emissions, measured with a spectrometer just

  13. NATIONAL INVENTORIES FOR AREA SOURCE FUEL COMBUSTION AND GASOLINE MARKETING IN 1999

    EPA Science Inventory

    The product will be a set of estimates of county-level 1999 emissions of all relevant air pollutants from gasoline marketing and from the combustion of fuel by "area" sources, i.e., those too small be be required to report their emissions individually....

  14. HAZARDOUS AIR POLLUTANTS FROM THE COMBUSTION OF AN EMULSIFIED HEAVY FUEL OIL IN A FIRETUBE BOILER

    EPA Science Inventory

    The report gives results of measuring emissions of hazardous air pollutants (HAPs) from the combustion flue gases of a No. 6 fuel oil, both with and without an emulsifying agent, in a 2.5 million Btu/hr (732 kW) firetube boiler with the purpose of determining the impacts of the e...

  15. New method for carbon dioxide recovery from the combustion of fossil fuel

    Microsoft Academic Search

    G. F. Berry; C. S. Wang; C. B. Dennis; A. M. Wolsky

    1988-01-01

    The relative size and composition of gas streams concomitant with a new method of carbon dioxide recovery are described and related to each other. This is done for two variations, dry recycle and wet recycle, of the new method. Calculations performed under the differing assumptions of complete combustion and chemical equilibrium are compared. The following fuels are considered: methane, CHâ;

  16. Method of controlling the fuel supply to an internal combustion engine at acceleration

    Microsoft Academic Search

    Y. Ishikawa; T. Kiuchi

    1986-01-01

    A method is described of controlling the supply of fuel to an internal combustion engine having an intake passage and a throttle valve arranged in the intake passage, wherein the value of at least one operating parameter of the engine is detected in synchronism with generation of pulses of a control signal generated at predetermined crank angle positions of the

  17. Characterizing combustible portions of urban refuse for potential use as fuel. Report of investigations

    Microsoft Academic Search

    H. Schultz; P. M. Sullivan; F. E. Walker

    1975-01-01

    Urban refuse that was mechanically separated at the U.S. Bureau of Mines pilot plant in College Park, Md., was successfully evaluated for its fuel values using standard coal analysis methods. Analyses performed on refuse samples taken from five sample points included moisture, ash, sulfur, chlorine, and heating value. It was recommended that characterization of the combustible portion of urban refuse

  18. Characterizing combustible portions of urban refuse for potential use as fuel

    Microsoft Academic Search

    H. Schultz; P. M. Sullivan; F. E. Walker

    1975-01-01

    Urban refuse that was mechanically separated at the U.S. Bureau of Mines pilot plant in College Park, Md., was successfully evaluated for its fuel values using standard coal analysis methods. Analyses performed on refuse samples taken from five sample points included moisture, ash, sulfur, chlorine, and heating value. It was recommended that characterization of the combustible portion of urban refuse

  19. EPA/IFP EUROPEAN WORKSHOP ON THE EMISSION ON NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION

    EPA Science Inventory

    The report summarizes the proceedings of an EPA/Institut Francais du Petrole (IFP) cosponsored workshop addressing direct nitrous oxide (N2O) emission from fossil fuel combustion. The third in a series, it was held at the IFP in Rueil-Malmaison, France, on June 1-2, 1988. Increas...

  20. Scholarly research program in fuel analysis and combustion research. Final report, September 1987-September 1992

    SciTech Connect

    Striebich, R.C.

    1993-02-01

    A total of 40 individually funded tasks were performed under this effort. These tasks were concerned with many fuel analysis and combustion research, conducted for the Fuels Branch (WL/POSF), Lubrications Branch (WL/POSL) and other Aero Propulsion and Power Directorate Laboratories. This report is a compilation of 1-2 page summaries from each of the tasks. More information on each task is available in the technical reports, journal articles, letter reports or informal information listed for the project. Although the subjects covered under this contract are too varied to list here, the most often addressed areas were research topics in gas chromatography and related instrumentation, thermal stability testing and methods development, lubrications research and combustion studies.... Chemometrics flames, Fuel analysis, Mass spectrometry, Shelf Life, CARS, Thermal stability, P-Hydrogen detector, Gas chromatography, Atomic emission, High density fuel, System for Thermal Diagnostic Studies (STDS).

  1. Vacuum Plasma Spray of CuCrNb Alloy for Advanced Liquid - Fuel Combustion Chambers

    NASA Technical Reports Server (NTRS)

    Zimmerman, Frank

    2000-01-01

    The copper-8 atomic percent chromium-4 atomic percent niobium (CuCrNb) alloy was developed by Glenn Research Center (formally Lewis Research Center) as an improved alloy for combustion chamber liners. In comparison to NARloy-Z, the baseline (as in Space Shuttle Main Engine) alloy for such liners, CuCrNb demonstrates mechanical and thermophysical properties equivalent to NARloy-Z, but at temperatures 100 C to 150 C (180 F to 270 F) higher. Anticipated materials related benefits include decreasing the thrust cell liner weight 5% to 20%, increasing the service life at least two fold over current combustion chamber design, and increasing the safety margins available to designers. By adding an oxidation and thermal barrier coating to the liner, the combustion chamber can operate at even higher temperatures. For all these benefits, however, this alloy cannot be formed using conventional casting and forging methods because of the levels of chromium and niobium, which exceed their solubility limit in copper. Until recently, the only forming process that maintains the required microstructure of CrNb intermetallics is powder metallurgy formation of a billet from powder stock, followed by extrusion. This severely limits its usefulness in structural applications, particularly the complex shapes required for combustion chamber liners. Vacuum plasma spray (VPS) has been demonstrated as a method to form structural articles including small combustion chambers from the CuCrNb alloy. In addition, an oxidation and thermal barrier layer can be formed integrally on the hot wall of the liner that improve performance and extend service life. This paper discusses the metallurgy and thermomechanical properties of VPS formed CuCrNb versus the baseline powder metallurgy process, and the manufacturing of small combustion chamber liners at Marshall Space Flight Center using the VPS process. The benefits to advanced propulsion initiatives of using VPS to fabricate combustion chamber liners while maintaining the superior CuCrNb properties are also presented.

  2. Influence of coal properties on forward combustion in laminar flow

    SciTech Connect

    Lockwood, W.R.; Corlett, W.R.; Mortazaui, H.R.; Emery, A.F.

    1986-07-01

    Numerical results are presented for forward combustion in coal channels wherein the flow is laminar. The work is motivated by the need to describe deviations from ideal permeative flow characteristics in theoretical models of underground rubble gasification. For simplicity, the geometry is idealized to a straight circular channel of initially uniform diameter. Coal and inlet gas properties, as well as gas flow rate and initial channel diameter, are arbitrary. A baseline case, in which O/sub 2/-steam is injected into a channel in virgin coal, is chosen to match laboratory work reported by other investigators. The results of independent variation of six major parameters are also shown. Finally, representative results are presented for injection of a hot mixture of steam and gasification products into hot char.

  3. Reduced bed agglomeration by co-combustion biomass with peat fuels in a fluidized bed

    SciTech Connect

    Karin Lundholm; Anders Nordin; Marcus Oehman; Dan Bostroem [Umeaa University, Umeaa (Sweden). Energy Technology and Thermal Process Chemistry

    2005-12-01

    Fluidized bed combustion is an energy conversion technology that is very suitable for biomass combustion because of its fuel flexibility and low process temperatures. However, agglomeration of bed material may cause severe operating problems. To prevent or at least reduce this, peat has been suggested as an additive to the main fuels. Nevertheless, the characteristics of peat fuels vary and there is limited information of the effect of different peat fuels and of the mechanisms behind the agglomeration prevention. The objectives of the present work were therefore to: (I) quantify the potential positive effect by co-combustion peat with forest fuels in terms of initial agglomeration temperatures; (ii) determine the amount of peat fuel that is needed to significantly reduce the agglomeration tendencies; and, if possible, (iii) elucidate the governing mechanisms. The results showed that all peat fuels prevented agglomeration in the studied interval of 760-1020{sup o}C and even as little as 5% peat fuel was found to have significant effects. The results also indicated that the mechanism of the agglomeration prevention varies between different peat fuels. Possible mechanisms are the minerals in the peat fuel retain alkali, which then is either elutriated up from the bed or captured in the bed; calcium and other refractory elements increase the melting temperature and thereby counteract the melting of alkali; and sulfur reacts with alkali metals and the alkali sulfates is either elutriated up from the bed or prevents agglomeration by increased melting temperature and lowered viscosity. Results from elemental analysis of the coating on bed particles showed that all mixtures with peat fuel resulted in a decreased or unchanged fraction of potassium and an increased fraction of aluminum in the coatings. The results also indicated a complex relationship between the fuel inorganic contents and the agglomeration process. 21 refs., 6 figs., 5 tabs.

  4. Quantifying hazardous species in particulate matter derived from fossil-fuel combustion.

    PubMed

    Huggins, Frank E; Huffman, Gerald P; Linak, William P; Miller, C Andrew

    2004-03-15

    An analysis protocol that combines X-ray absorption near-edge structure spectroscopy with selective leaching has been developed to examine hazardous species in size-segregated particulate matter (PM) samples derived from the combustion of fossil fuels. The protocol has been used to identify and determine quantitatively the amounts of three important toxic species in combustion-derived PM: viz., nickel sulfides in residual oil fly ash (ROFA) PM, and Cr(VI) and As(III) species in coal fly ash PM. Although it has been assumed that these toxic species might exist in PM derived from fossil-fuel combustion, the results presented here constitute the first direct determination of them in combustion-derived PM and their potential bioavailability. Detailed information on the presence of these toxic species in PM samples is of significant interest to epidemiological and toxicological studies of the health effects of both source and ambient PM. Additionally, information is obtained on insoluble forms that may be useful for source attribution and on the distribution of phases between size fractions that may be related to formation mechanisms of specific toxic species during combustion. PMID:15074697

  5. Structural and optical properties of YAG:Ce 3+ phosphors by sol–gel combustion method

    Microsoft Academic Search

    Guodong Xia; Shengming Zhou; Junji Zhang; Jun Xu

    2005-01-01

    High-quality Ce3+-doped Y3Al5O12 (YAG:Ce3+) phosphors were synthesized by a facile sol–gel combustion method. In this sol–gel combustion process, citric acid acts as a fuel for combustion, traps the constituent cations and reduces the diffusion length of the precursors. The XRD and FT-IR results show that YAG phase can form through sintering at 900°C for 2h. This temperature is much lower

  6. Sulphur impacts during pulverised coal combustion in oxy-fuel technology for carbon capture and storage

    Microsoft Academic Search

    Rohan Stanger; Terry Wall

    2011-01-01

    The oxy-fuel process is one of three carbon capture technologies which supply CO2 ready for sequestration – the others being post-combustion capture and IGCC with carbon capture. As yet no technology has emerged as a clear winner in the race to commercial deployment. The oxy-fuel process relies on recycled flue gas as the main heat carrier through the boiler and

  7. Fuel properties of eleven vegetable oils

    SciTech Connect

    Goering, C.E.; Schwab, A.W.; Daugherty, M.J.; Pryde, E.H.; Keakin, A.J.

    1981-01-01

    Eleven vegetable oils that can be grown as domestic field crops were identified for inclusion in a comparative study. Sample lots of each oil were subjected to ASTM tests appropriate for diesel fuels. The tests identified some problem areas with vegetable oil fuels. The oil samples were also characterized chemically and certain fuel properties were correlated to chemical composition. 10 refs.

  8. Antioxidant properties of myocardial fuels

    Microsoft Academic Search

    Robert T. Mallet; Jie Sun

    2003-01-01

    Oxidative metabolism of blood-borne fuels provides myocardium the energy required to sustain its contractile performance. Recent research has revealed that, in addition to supplying energy, certain fuels are able to detoxify harmful oxidants and bolster the myocardium's endogenous antioxidant defenses. These antioxidant capabilities could potentially protect the myocardium from the ravages of reactive oxygen and nitrogen intermediates generated upon reperfusion

  9. Aviation fuel property effects on altitude relight

    NASA Technical Reports Server (NTRS)

    Venkataramani, K.

    1987-01-01

    The major objective of this experimental program was to investigate the effects of fuel property variation on altitude relight characteristics. Four fuels with widely varying volatility properties (JP-4, Jet A, a blend of Jet A and 2040 Solvent, and Diesel 2) were tested in a five-swirl-cup-sector combustor at inlet temperatures and flows representative of windmilling conditions of turbofan engines. The effects of fuel physical properties on atomization were eliminated by using four sets of pressure-atomizing nozzles designed to give the same spray Sauter mean diameter (50 + or - 10 micron) for each fuel at the same design fuel flow. A second series of tests was run with a set of air-blast nozzles. With comparable atomization levels, fuel volatility assumes only a secondary role for first-swirl-cup lightoff and complete blowout. Full propagation first-cup blowout were independent of fuel volatility and depended only on the combustor operating conditions.

  10. EMISSION MEASUREMENTS IN DUAL FUELED INTERNAL COMBUSTION ENGINE TESTS

    Microsoft Academic Search

    A. F. Orlando; E. Santos; L. G. do Val

    Dual fueled engine test procedures and result interpretation are not available in the literature, This paper describes a methodology for calculating the emission mass flow rates, using the chemical reaction mass balance of the components. The experimental data were obtained from tests made at the MWM dynamometer. Starting from basic principles, the hydrocarbon (HC) mass flow rate was related to

  11. EMISSIONS ASSESSMENT FOR REFUSE-DERIVED FUEL COMBUSTION

    EPA Science Inventory

    The RDF and coal were burned in a small spreader-stoker fired boiler. The parameters that were varied in this program were RDF type and amount of coal burned with the RDF. In two experiments a waste chemical, triethanolamine, was added to the fuel, and its destruction efficiency ...

  12. A coal-fueled combustion turbine cogeneration system with topping combustion

    Microsoft Academic Search

    J. M. Beer; R. V. Garland

    1997-01-01

    Cogeneration systems fired with coal or other solid fuels and containing conventional extracting-condensing or back pressure steam turbines can be found throughout the world. A potentially more economical plant of higher output per unit thermal energy is presented that employs a pressurized fluidized bed (PFB) and coal carbonizer. The carbonizer produces a char that is fed to the PFB and

  13. Mass spectrometric analysis and aerodynamic properties of various types of combustion-related aerosol particles

    Microsoft Academic Search

    J. Schneider; S. Weimer; F. Drewnick; S. Borrmann; G. Helas; P. Gwaze; O. Schmid; M. O. Andreae; U. Kirchner

    2006-01-01

    Various types of combustion-related particles in the size range between 100 and 850nm were analyzed with an aerosol mass spectrometer and a differential mobility analyzer. The measurements were performed with particles originating from biomass burning, diesel engine exhaust, laboratory combustion of diesel fuel and gasoline, as well as from spark soot generation. Physical and morphological parameters like fractal dimension, effective

  14. Combustion tests of a turbine simulator burning low Btu fuel from a fixed bed gasifier

    SciTech Connect

    Cook, C.S.; Abuaf, N.; Feitelberg, A.S.; Hung, S.L.; Najewicz, D.J.; Samuels, M.S.

    1993-11-01

    One of the most efficient and environmentally compatible coal fueled power generation technologies is the integrated gasification combined cycle (IGCC) concept. Commercialization of the IGCC/HGCU concept requires successful development of combustion systems for high temperature low Btu fuel in gas turbines. Toward this goal, a turbine combustion system simulator has been designed, constructed, and fired with high temperature low Btu fuel. Fuel is supplied by a pilot scale fixed bed gasifier and hot gas desulfurization system. The primary objectives of this project are: (1) demonstration of long term operability of the turbine simulator with high temperature low Btu fuel; (2) measurement of NO{sub x}, CO, and particulate emissions; and (3) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle. In a related project, a reduced scale rich-quench-lean (RQL) gas turbine combustor has been designed, constructed, and fired with simulated low Btu fuel. The overall objective of this project is to develop an RQL combustor with lower conversion of fuel bound nitrogen (FBN) to NO{sub x} than a conventional combustor.

  15. Combustion characteristics of hydrogen–hydrocarbon hybrid fuels

    Microsoft Academic Search

    Ahsan R Choudhuri; S. R Gollahalli

    2000-01-01

    A comparative study of the flame structure and characteristics of diffusion flames of the mixture of hydrogen–hydrocarbon (natural gas and propane) hybrid fuel in a slow co-flowing stream of air is presented. The volumetric content of natural gas and propane in the mixture was varied from 0–35%. The burner exit Reynolds number was varied from 150–3000. Measurements include flame length,

  16. Comparative bio-fuel performance in internal combustion engines

    Microsoft Academic Search

    R. J. Crookes

    2006-01-01

    An experimental programme examining performance and emissions from spark- and compression-ignition engines, running on a variety of bio-fuels, including simulated bio-gas and commercial seed oil is presented. Both engines were single-cylinder laboratory-type engines of comparable power output having variable speed and load capability, the spark-ignition engine additionally having variable compression ratio. For bio-gas, containing carbon dioxide, emissions of oxides of

  17. Large Eddy Simulation of the Fuel Injection in Scramjet Combustion Chambers

    NASA Astrophysics Data System (ADS)

    Rana, Z. A.; Thornber, B. J. R.; Drikakis, D.

    2011-08-01

    Fuel injection in a typical scramjet combustion chamber is a very challenging flow to characterise either in ex- perimental or computational studies. It involves multi- species compressible turbulent features with complex coherent flow structures arising as a result of sonic fuel injection transverse or inclined to the free-stream supersonic flow. In this paper the fuel injection in the HyShot- II combustion chamber is studied using an Implicit LES method employing a modified very high order accurate numerical method. To gain accurate mean inflow boundary conditions, a thermally perfect gas formulation has been employed in preliminary simulations of the inlet ramp and cowl configuration. The results of these simulations are presented and validated against wind tunnel data.

  18. Low NOx heavy fuel combustor concept program. Phase 1: Combustion technology generation

    NASA Technical Reports Server (NTRS)

    Lew, H. G.; Carl, D. R.; Vermes, G.; Dezubay, E. A.; Schwab, J. A.; Prothroe, D.

    1981-01-01

    The viability of low emission nitrogen oxide (NOx) gas turbine combustors for industrial and utility application. Thirteen different concepts were evolved and most were tested. Acceptable performance was demonstrated for four of the combustors using ERBS fuel and ultralow NOx emissions were obtained for lean catalytic combustion. Residual oil and coal derived liquids containing fuel bound nitrogen (FBN) were also used at test fuels, and it was shown that staged rich/lean combustion was effective in minimizing the conversion of FBN to NOx. The rich/lean concept was tested with both modular and integral combustors. While the ceramic lined modular configuration produced the best results, the advantages of the all metal integral burners make them candidates for future development. An example of scaling the laboratory sized combustor to a 100 MW size engine is included in the report as are recommendations for future work.

  19. Chemical Kinetic Simulation of the Combustion of Bio-based Fuels

    SciTech Connect

    Ashen, Ms. Refuyat [Oak Ridge High School; Cushman, Ms. Katherine C. [Oak Ridge High School

    2007-10-01

    Due to environmental and economic issues, there has been an increased interest in the use of alternative fuels. However, before widespread use of biofuels is feasible, the compatibility of these fuels with specific engines needs to be examined. More accurate models of the chemical combustion of alternative fuels in Homogeneous Charge Compression Ignition (HCCI) engines are necessary, and this project evaluates the performance of emissions models and uses the information gathered to study the chemical kinetics involved. The computer simulations for each alternative fuel were executed using the Chemkin chemical kinetics program, and results from the runs were compared with data gathered from an actual engine that was run under similar conditions. A new heat transfer mechanism was added to the existing model's subroutine, and simulations were then conducted using the heat transfer mechanism. Results from the simulation proved to be accurate when compared with the data taken from the actual engine. The addition of heat transfer produced more realistic temperature and pressure data for biodiesel when biodiesel's combustion was simulated in an HCCI engine. The addition of the heat transfer mechanism essentially lowered the peak pressures and peak temperatures during combustion of all fuels simulated in this project.

  20. Finial Scientific/Technical Report: Application of a Circulating Fluidized Bed Process for the Chemical Looping Combustion of Solid Fuel

    SciTech Connect

    Dr. Wei-Ping Pan; Dr. John T. Riley

    2005-10-10

    Chemical Looping Combustion is a novel combustion technology for the inherent separation of the greenhouse gas, CO{sub 2}. In 1983, Richter and Knoche proposed reversible combustion, which utilized both the oxidation and reduction of metal. Metal associated with its oxidized form as an oxygen carrier was circulated between two reactors--oxidizer and reducer. In the reducer, the solid oxygen carrier reacts with the fuel to produce CO{sub 2}, H{sub 2}O and elemental metal only. Pure CO{sub 2} will be obtained in the exit gas stream from the reducer after H{sub 2}O is condensed. The pure CO{sub 2} is ready for subsequent sequestration. In the oxidizer, the elemental metal reacts with air to form metal oxide and separate oxygen from nitrogen. Only nitrogen and some unused oxygen are emitted from the oxidizer. The advantage of CLC compared to normal combustion is that CO{sub 2} is not diluted with nitrogen but obtained in a relatively pure form without any energy needed for separation. In addition to the energy-free purification of CO{sub 2}, the CLC process also provides two other benefits. First, NO{sub x} formation can be largely eliminated. Secondly, the thermal efficiency of a CLC system is very high. Presently, the CLC process has only been used with natural gas. An oxygen carrier based on an energy balance analysis and thermodynamics analysis was selected. Copper (Cu) seems to be the best choice for the CLC system for solid fuels. From this project, the mechanisms of CuO reduction by solid fuels may be as follows: (1) If pyrolysis products of solid fuels are available, reduction of CuO could start at about 400 C or less. (2) If pyrolysis products of solid fuels are unavailable and the reduction temperature is lower, reduction of CuO could occur at an onset temperature of about 500 C, char gasification reactivity in CO{sub 2} was lower at lower temperatures. (3) If pyrolysis products of solid fuels are unavailable and the reduction temperature is higher than 750 C, all reaction reactivities were improved, especially the CO{sub 2} gasification reactivity of char. Thus, the reduction of CuO by the gasification product CO could proceed quickly. Based on the results obtained, the following coal characteristics would be desirable for the Chemical Looping Combustion process: high volatile matter with a high reactivity of the char produced. PRB coal meets these criteria while being comparatively less expensive and also very abundant. The high moisture content present in PRB coal might also increase the reactivity for char gasification through the development of pore structure and specific surface area in the char during pyrolysis. Biomass materials are also suitable, considering the reaction mechanism of CLC system of solid fuels. The feasibility of the chemical looping combustion process of solid fuels was verified by focusing on PRB coal and biomass. Based on PRB coal as the preferred solid fuel in the development of the CLC system, the mass, energy and system in a dual reactor recirculation system has been determined. In the Cu oxidation tests, it was confirmed that the heating rate is the most important effect on the Cu oxidation process. Lower heating rates and lower operational temperatures would result in incomplete conversion of Cu to CuO. Cu{sub 2}O may be the intermediate product. The operating temperature did not affect the reaction rate of the oxidation process. Under any operating conditions, the exothermic properties are clearly shown.

  1. Fuel-air mixing and combustion in a two-dimensional Wankel engine

    NASA Technical Reports Server (NTRS)

    Shih, T. I.-P.; Schock, H. J.; Ramos, J. I.

    1987-01-01

    A two-equation turbulence model, an algebraic grid generalization method, and an approximate factorization time-linearized numerical technique are used to study the effects of mixture stratification at the intake port and gaseous fuel injection on the flow field and fuel-air mixing in a two-dimensional rotary engine model. The fuel distribution in the combustion chamber is found to be a function of the air-fuel mixture fluctuations at the intake port. It is shown that the fuel is advected by the flow field induced by the rotor and is concentrated near the leading apex during the intake stroke, while during compression, the fuel concentration is highest near the trailing apex and is lowest near the rotor. It is also found that the fuel concentration near the trailing apex and rotor is small except at high injection velocities.

  2. Effects of emulsification variables on fuel properties of two- and three-phase biodiesel emulsions

    Microsoft Academic Search

    Cherng-Yuan Lin; Shiou-An Lin

    2007-01-01

    Biodiesel has attractive fuel properties such as excellent biodegradability and lubricity, almost no emissions of sulfur oxides, PAH and n-PAH, reduced CO2, PM and CO emission, superior combustion efficiency, etc. However, burning of biodiesel generally produces higher levels of NOx emissions, primarily due to its high oxygen content. In this study, the emulsification technology has been considered to reduce the

  3. Achieve Continuous Injection of Solid Fuels into Advanced Combustion System Pressures

    SciTech Connect

    Derek L. Aldred; Timothy Saunders

    2005-07-01

    The overall objective of this project is the development of a mechanical rotary-disk feeder, known as the Stamet Posimetric High Pressure Solids Feeder System, to feed dry granular coal continuously and controllably into pressurized environments of up to 35 kg/cm{sup 2} (500 psi). This was to be accomplished in two phases. The first task was to review materials handling experience in pressurized operations as it related to the target pressures for this project, and review existing coal preparation processes and specifications currently used in advanced combustion systems. Samples of existing fuel materials were obtained and tested to evaluate flow, sealing and friction properties. This provided input data for use in the design of the Stamet Feeders for the project, and ensured that the material specification used met the requirements of advanced combustion & gasification systems. Ultimately, Powder River Basin coal provided by the PSDF facility in Wilsonville, AL was used as the basis for the feeder design and test program. Based on the material property information, a Phase 1 feeder system was designed and built to accomplish feeding the coal to an intermediate pressure up to 21 kg/cm{sup 2} (300 psi) at feed rates of approximately 100 kilograms (220lbs) per hour. The pump & motor system was installed in a custom built test rig comprising an inlet vessel containing an active live-wall hopper mounted in a support frame, transition into the pump inlet, transition from pump outlet and a receiver vessel containing a receiver drum supported on weigh cells. All pressure containment on the rig was rated for the final pressure requirement of 35 kg/cm{sup 2} (500psi). A program of testing and modification was carried out in Stamet's facility in CA, culminating in successful feeding of coal into the Phase 1 target of 21 kg/cm{sup 2} (300psi) gas pressure in December 2003. Further testing was carried out at CQ Inc's facility in PA, providing longer run times and experience of handling and feeding the coal in winter conditions. Based on the data developed through the testing of the Phase I unit, a Phase II system was designed for feeding coal into pressures of up to 35 kg/cm{sup 2} (500 psi). A further program of testing and modification was then carried out in Stamet's facility, with the target pressure being achieved in January 2005. Repeated runs at pressure were achieved, and optimization of the machine resulted in power reductions of 60% from the first successful pressure runs. General design layout of a commercial-scale unit was conducted, and preliminary cost estimates for a commercial unit obtained.

  4. Graphite fuels combustion off-gas treatment options

    SciTech Connect

    Kirkham, R.J.; Lords, R.E.

    1993-03-01

    Scenarios for burning bulk graphite and for burning crushed fuel particles from graphite spent nuclear fuels have been considered. Particulates can be removed with sintered metal filters. Subsequent cooling would then condense semi-volatile fission products into or onto a particulate. These particulates would be trapped by a second sintered metal filter or downstream packed bed. A packed bed scrub column can be used to eliminate most of the iodine-129 and tritium. A molecular sieve bed is proposed to collect the residual {sup 129}I and other tramp radionuclides downstream (Ruthenium, etc.). Krypton-85 can be recovered, if need be, either by cryogenics or by the KALC process (Krypton Adsorption in Liquid Carbon dioxide). Likewise carbon-14 in the form of carbon dioxide could be collected with a caustic or lime scrub solution and incorporated into a grout. Sulfur dioxide present will be well below regulatory concern level of 4.0 tons per year and most of it would be removed by the scrubber. Carbon monoxide emissions will depend on the choice of burner and start-up conditions. Should the system exceed the regulatory concern level, a catalytic converter in the final packed bed will be provided. Radon and its daughters have sufficiently short half-lives (less than two minutes). If necessary, an additional holdup bed can be added before the final HEPA filters or additional volume can be added to the molecular sieve bed to limit radon emissions. The calculated total effective dose equivalent at the Idaho National Engineering Laboratory boundary from a single release of all the {sup 3}, {sup 14}C, {sup 85}Kr, and {sup 129}I in the total fuel mass if 0.43 mrem/year.

  5. Combined catalysts for the combustion of fuel in gas turbines

    DOEpatents

    Anoshkina, Elvira V.; Laster, Walter R.

    2012-11-13

    A catalytic oxidation module for a catalytic combustor of a gas turbine engine is provided. The catalytic oxidation module comprises a plurality of spaced apart catalytic elements for receiving a fuel-air mixture over a surface of the catalytic elements. The plurality of catalytic elements includes at least one primary catalytic element comprising a monometallic catalyst and secondary catalytic elements adjacent the primary catalytic element comprising a multi-component catalyst. Ignition of the monometallic catalyst of the primary catalytic element is effective to rapidly increase a temperature within the catalytic oxidation module to a degree sufficient to ignite the multi-component catalyst.

  6. Health effects of residential wood smoke particles: the importance of combustion conditions and physicochemical particle properties

    PubMed Central

    Kocbach Břlling, Anette; Pagels, Joakim; Yttri, Karl Espen; Barregard, Lars; Sallsten, Gerd; Schwarze, Per E; Boman, Christoffer

    2009-01-01

    Background Residential wood combustion is now recognized as a major particle source in many developed countries, and the number of studies investigating the negative health effects associated with wood smoke exposure is currently increasing. The combustion appliances in use today provide highly variable combustion conditions resulting in large variations in the physicochemical characteristics of the emitted particles. These differences in physicochemical properties are likely to influence the biological effects induced by the wood smoke particles. Outline The focus of this review is to discuss the present knowledge on physicochemical properties of wood smoke particles from different combustion conditions in relation to wood smoke-induced health effects. In addition, the human wood smoke exposure in developed countries is explored in order to identify the particle characteristics that are relevant for experimental studies of wood smoke-induced health effects. Finally, recent experimental studies regarding wood smoke exposure are discussed with respect to the applied combustion conditions and particle properties. Conclusion Overall, the reviewed literature regarding the physicochemical properties of wood smoke particles provides a relatively clear picture of how these properties vary with the combustion conditions, whereas particle emissions from specific classes of combustion appliances are less well characterised. The major gaps in knowledge concern; (i) characterisation of the atmospheric transformations of wood smoke particles, (ii) characterisation of the physicochemical properties of wood smoke particles in ambient and indoor environments, and (iii) identification of the physicochemical properties that influence the biological effects of wood smoke particles. PMID:19891791

  7. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Astrophysics Data System (ADS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-11-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  8. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide a useful engineering technology base in the development of hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed and manufactured for conducting experimental investigations. Oxidizer (LOX or GOX) supply and control systems have been designed and partly constructed for the head-end injection into the test chamber. Experiments using HTPB fuel, as well as fuels supplied by NASA designated industrial companies will be conducted. Design and construction of fuel casting molds and sample holders have been completed. The portion of these items for industrial company fuel casting will be sent to the McDonnell Douglas Aerospace Corporation in the near future. The study focuses on the following areas: observation of solid fuel burning processes with LOX or GOX, measurement and correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study (Part 2) also being conducted at PSU.

  9. Formation, ignition, and combustion of a stratified-charge fuel-air mixture in an open-chamber combustion bomb. [Thesis

    Microsoft Academic Search

    1975-01-01

    The interrelated processes of mixture formation, ignition, and the early stages of combustion that occur in one type of open-chamber, stratified-charge engines were studied experimentally by simulating engine conditions in a constant-volume combustion bomb. The apparatus designed and developed for this research permits a well-controlled single injection of liquid fuel into a steady-state environment of hot, high-pressure, fan-driven swirling air

  10. System approach to the analysis of an integrated oxy-fuel combustion power plant

    NASA Astrophysics Data System (ADS)

    Zi?bik, Andrzej; G?adysz, Pawe?

    2014-09-01

    Oxy-fuel combustion (OFC) belongs to one of the three commonly known clean coal technologies for power generation sector and other industry sectors responsible for CO2 emissions (e.g., steel or cement production). The OFC capture technology is based on using high-purity oxygen in the combustion process instead of atmospheric air. Therefore flue gases have a high concentration of CO2. Due to the limited adiabatic temperature of combustion some part of CO2 must be recycled to the boiler in order to maintain a proper flame temperature. An integrated oxy-fuel combustion power plant constitutes a system consisting of the following technological modules: boiler, steam cycle, air separation unit, cooling water and water treatment system, flue gas quality control system and CO2 processing unit. Due to the interconnections between technological modules, energy, exergy and ecological analyses require a system approach. The paper present the system approach based on the `input-output' method to the analysis of the: direct energy and material consumption, cumulative energy and exergy consumption, system (local and cumulative) exergy losses, and thermoecological cost. Other measures like cumulative degree of perfection or index of sustainable development are also proposed. The paper presents a complex example of the system analysis (from direct energy consumption to thermoecological cost) of an advanced integrated OFC power plant.

  11. Emissions from laboratory combustion of wildland fuels: emission factors and source profiles.

    PubMed

    Chen, L W Antony; Moosmüller, Hans; Arnott, W Patrick; Chow, Judith C; Watson, John G; Susott, Ronald A; Babbitt, Ronald E; Wold, Cyle E; Lincoln, Emily N; Hao, Wei Min

    2007-06-15

    Combustion of wildland fuels represents a major source of particulate matter (PM) and light-absorbing elemental carbon (EC) on a national and global scale, but the emission factors and source profiles have not been well characterized with respect to different fuels and combustion phases. These uncertainties limit the accuracy of current emission inventories, smoke forecasts, and source apportionments. This study investigates the evolution of gaseous and particulate emission and combustion efficiency by burning wildland fuels in a laboratory combustion facility. Emission factors for carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxides (NO(x)), PM, light extinction and absorption cross sections, and spectral scattering cross sections specific to flaming and smoldering phases are reported. Emission factors are generally reproducible within +/- 20% during the flaming phase, which, despite its short duration, dominates the carbon emission (mostly in the form of CO2) and the production of light absorption and EC. Higher and more variable emission factors for CO, THC, and PM are found during the smoldering phase, especially for fuels containing substantial moisture. Organic carbon (OC) and EC mass account for a majority (i.e., > 60%) of PM mass; other important elements include potassium, chlorine, and sulfur. Thermal analysis separates the EC into subfractions based on analysis temperature demonstrating that high-temperature EC (EC2; at 700 degrees C) varies from 1% to 70% of PM among biomass burns, compared to 75% in kerosene soot. Despite this, the conversion factor between EC and light absorption emissions is rather consistent across fuels and burns, ranging from 7.8 to 9.6 m2/g EC. Findings from this study should be considered in the development of PM and EC emission inventories for visibility and radiative forcing assessments. PMID:17626431

  12. Combustion aspects of the reapplication of energetic materials as fuels as a viable demil technology

    SciTech Connect

    Baxter, L.; Davis, K.; Sinquefield, S.; Huey, S.; Lipkin, J.; Shah, D.; Ross, J.; Sclippa, G. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility

    1996-05-01

    This investigation addresses the combustion-related aspects of the reapplication of energetic materials as fuels in boilers as an economically viable and environmentally acceptable use of excess energetic materials. The economics of this approach indicate that the revenues from power generation and chemical recovery approximately equal the costs of boiler modification and changes in operation. The primary tradeoff is the cost of desensitizing the fuels against the cost of open burn/open detonation (OB/OD) or other disposal techniques. Two principal combustion-related obstacles to the use of energetic-material-derived fuels are NO{sub x} generation and the behavior of metals. NO{sub x} measurements obtained in this investigation indicate that the nitrated components (nitrocellulose, nitroglycerin, etc.) of energetic materials decompose with NO{sub x} as the primary product. This can lead to high uncontrolled NO{sub x} levels (as high as 2,600 ppm on a 3% O{sub 2} basis for a 5% blend of energetic material in the fuel). NO{sub x} levels are sensitive to local stoichiometry and temperature. The observed trends resemble those common during the combustion of other nitrogen-containing fuels. Implications for NO{sub x} control strategies are discussed. The behavior of inorganic components in energetic materials tested in this investigation could lead to boiler maintenance problems such as deposition, grate failure, and bed agglomeration. The root cause of the problem is the potentially extreme temperature generated during metal combustion. Implications for furnace selection and operation are discussed.

  13. Polycyclic aromatic hydrocarbon emissions from the combustion of alternative fuels in a gas turbine engine.

    PubMed

    Christie, Simon; Raper, David; Lee, David S; Williams, Paul I; Rye, Lucas; Blakey, Simon; Wilson, Chris W; Lobo, Prem; Hagen, Donald; Whitefield, Philip D

    2012-06-01

    We report on the particulate-bound polycyclic aromatic hydrocarbons (PAH) in the exhaust of a test-bed gas turbine engine when powered by Jet A-1 aviation fuel and a number of alternative fuels: Sasol fully synthetic jet fuel (FSJF), Shell gas-to-liquid (GTL) kerosene, and Jet A-1/GTL 50:50 blended kerosene. The concentration of PAH compounds in the exhaust emissions vary greatly between fuels. Combustion of FSJF produces the greatest total concentration of PAH compounds while combustion of GTL produces the least. However, when PAHs in the exhaust sample are measured in terms of the regulatory marker compound benzo[a]pyrene, then all of the alternative fuels emit a lower concentration of PAH in comparison to Jet A-1. Emissions from the combustion of Jet A-1/GTL blended kerosene were found to have a disproportionately low concentration of PAHs and appear to inherit a greater proportion of the GTL emission characteristics than would be expected from volume fraction alone. The data imply the presence of a nonlinear relation between fuel blend composition and the emission of PAH compounds. For each of the fuels, the speciation of PAH compounds present in the exhaust emissions were found to be remarkably similar (R(2) = 0.94-0.62), and the results do provide evidence to support the premise that PAH speciation is to some extent indicative of the emission source. In contrast, no correlation was found between the PAH species present in the fuel with those subsequently emitted in the exhaust. The results strongly suggests that local air quality measured in terms of the particulate-bound PAH burden could be significantly improved by the use of GTL kerosene either blended with or in place of Jet A-1 kerosene. PMID:22534092

  14. Combustion of nanofluid fuels with the addition of boron and iron particles at dilute and dense concentrations

    E-print Network

    Qiao, Li

    stage when all the liquid fuel had been consumed. Sometimes this agglomerate may not burn if the energy reserved. 1. Introduction Nanofluid fuels, a new class of nanotechnology-based fuels, are liquid fuels] recently studied the combustion of monopropellant nitromethane contain- ing colloidal particles

  15. Fuel supply control system for internal combustion engines, having a function of leaning mixture in an engine low load region

    Microsoft Academic Search

    Hasegawa

    1984-01-01

    A fuel supply control system for use with an internal combustion engine in which a fuel quantity adjusting means which controls the quantity of fuel being supplied to the engine is electrically controlled in response to operating condition of the engine to obtain a desired amount of fuel being supplied to the engine. The system includes means responsive to the

  16. Impact of aviation non-CO? combustion effects on the environmental feasibility of alternative jet fuels.

    PubMed

    Stratton, Russell W; Wolfe, Philip J; Hileman, James I

    2011-12-15

    Alternative fuels represent a potential option for reducing the climate impacts of the aviation sector. The climate impacts of alternatives fuel are traditionally considered as a ratio of life cycle greenhouse gas (GHG) emissions to those of the displaced petroleum product; however, this ignores the climate impacts of the non-CO(2) combustion effects from aircraft in the upper atmosphere. The results of this study show that including non-CO(2) combustion emissions and effects in the life cycle of a Synthetic Paraffinic Kerosene (SPK) fuel can lead to a decrease in the relative merit of the SPK fuel relative to conventional jet fuel. For example, an SPK fuel option with zero life cycle GHG emissions would offer a 100% reduction in GHG emissions but only a 48% reduction in actual climate impact using a 100-year time window and the nominal climate modeling assumption set outlined herein. Therefore, climate change mitigation policies for aviation that rely exclusively on relative well-to-wake life cycle GHG emissions as a proxy for aviation climate impact may overestimate the benefit of alternative fuel use on the global climate system. PMID:22106939

  17. A parametric study on natural gas fueled HCCI combustion engine using a multi-zone combustion model

    Microsoft Academic Search

    Ali Yousefzadi Nobakht; R. Khoshbakhi Saray; Arash Rahimi

    2011-01-01

    Homogenous Charge Combustion Ignition (HCCI) is a good method for higher efficiency and to reduce NOx and particulate matter simultaneously in comparison to conventional internal combustion engines. In HCCI engines, there is no direct control method for auto ignition time. A common way to indirectly control the ignition timing in HCCI combustion engines is varying engine’s parameters which can affect

  18. Fuel and physical properties of biodiesel components

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodiesel is an alternative diesel fuel derived from vegetable oils, animal fats or used oils. Specifically, biodiesel is the methyl or other alkyl esters of these oils or fats. Biodiesel also contains minor components such as free fatty acids and acylglycerols. Important fuel properties of biodi...

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

    NASA Astrophysics Data System (ADS)

    Za?e, M.; Barmina, I.; Kriško, V.; Gedrovi?s, M.; Desc?ickis, A.

    2009-01-01

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

  20. and Uncertainty in Stationary Natural Gas-fueled Internal Combustion Engine NOx and Total Organic Compounds Emission Factors

    Microsoft Academic Search

    H. Christopher Frey

    Quantitative methods for characterizing both variability and uncertainty are applied to case studies of emission factors for stationary natural gas-fueled internal combustion engines. NOx and Total Organic Carbon (TOC) emission data sets for lean burn engines were analyzed. Data were available for uncontrolled engines and for engines with pre-combustion chamber (PCC) and \\

  1. An analytical investigation of primary zone combustion temperatures and NOx production for turbulent jet flames using low-BTU fuels 

    E-print Network

    Carney, Christopher Mark

    1995-01-01

    The objective of this research project was to identify and determine the effect of jet burner operating variables that influence combustion of low-BTU gases. This was done by simulating the combustion of a low-BTU fuel in a jet flame and predicting...

  2. Alternative fuel firing in an atmospheric fluidized-bed combustion boiler. Final report. [Also with other waste fuels

    SciTech Connect

    Miraglio, A.; Tegen, P.

    1985-06-01

    In 1981, Northern States Power Company converted its 15 MW French Island Unit No. 2 from a stoker-fired boiler to an atomspheric fluidized bed combustor designed to burn wood waste. A joint project between Northern States Power and the Electric Power Research Institute was subsequently established to determine the impact on operations, performance, and emissions of cofiring a variety of low-grade waste fuels with wood waste in this unit. Alternate waste fuels fired were shredded rubber tires, shredded railroad ties, refuse derived fuel, Minnesota peat, and sewage sludge. Each fuel was cofired with wood waste under steady boiler conditions for 50 to 100 hours. Results from the initial alternate fuel tests showed incomplete combustion of the fluidized bed combustor. To correct this problem the overfire air system was modified to improve mixing in the furnace volume above the fluidized bed. After the overfire air system was modified, the fluidized bed combustor proved able to burn all waste fuels effectively, except rubber tires which were not re-tested. Fuel handling problems were encountered with refuse derived fuel, peat and sewage sludge, but did not prevent their successful firing. Fluidized bed contamination was experienced with steel wire from rubber tires and stones and steel pieces from railroad ties. Also, the particulate scrubber was overloaded when firing high ash fuels such as rubber tires and peat. 2 refs., 21 figs., 32 tabs.

  3. Combustion of solid fuel slabs with gaseous oxygen in a hybrid motor analog

    NASA Technical Reports Server (NTRS)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated- Polybutadiene) fuel cross linked with diisocyanate was burned with GOX under various operating conditions. Large amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed line system and combustion chamber, the pressure oscillations were drastically reduced from +/- 20% of the localized mean pressure to an acceptable range of +/- 1.5%. Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations arc thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thicknesses and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented. Several tests were conducted using, simultaneously, one translucent fuel slab and one fuel slab processed with carbon black powder. The addition of carbon black did not affect the measured regression rates or surface temperatures in comparison to the translucent fuel slabs.

  4. Combustion of solid fuel slabs with gaseous oxygen in a hybrid motor analog

    NASA Technical Reports Server (NTRS)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated Polybutadiene) fuel cross-linked with diisocyanate was burned with gaseous oxygen (GOX) under various operating conditions. Large-amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed-line system and combustion chamber, the pressure oscillations were drastically reduced from plus or minus 20% of the localized mean pressure to an acceptable range of plus or minus 1.5%. Embedded fine--wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading edge region, the subsurface thermal wave profiles in the upstream locations are thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real-time X-ray radiography and ultrasonic pulse echo techniques were used to determine the instantaneous web thicknesses and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented. Several tests were conducted using, simultaneously, one translucent fuel slab and one fuel slab processed with carbon black powder. The addition of carbon black did not affect the measured regression rates or surface temperatures in comparison to the translucent fuel slabs.

  5. Modeling of NO sensitization of IC engines surrogate fuels auto-ignition and combustion

    Microsoft Academic Search

    Jörg Anderlohr; A. Pires Da Cruz; Roda Bounaceur; Frédérique Battin-Leclerc

    2009-01-01

    This paper presents a new chemical kinetic model developed for the simulation of auto-ignition and combustion of engine surrogate fuel mixtures sensitized by the presence of NOx. The chemical mechanism is based on the PRF auto-ignition model (n-heptane\\/iso-octane) of Buda et al. [1] and the NO\\/n-butane\\/n-pentane model of Glaude et al. [2]. The later mechanism has been taken as a

  6. Modeling of NO sensitization of IC engines surrogate fuels auto-ignition and combustion

    Microsoft Academic Search

    Jörg Anderlohr; A. Pires Da Cruz; Roda Bounaceur; F. Battin Leclerc

    2009-01-01

    This paper presents a new chemical kinetic model developed for the simulation\\u000aof auto-ignition and combustion of engine surrogate fuel mixtures sensitized by\\u000athe presence of NOx. The chemical mechanism is based on the PRF auto-ignition\\u000amodel (n-heptane\\/iso-octane) of Buda et al. [1] and the NO\\/n-butane\\/n-pentane\\u000amodel of Glaude et al. [2]. The later mechanism has been taken as a

  7. Hetero\\/homogeneous combustion and stability maps in methane-fueled catalytic microreactors

    Microsoft Academic Search

    Symeon Karagiannidis; John Mantzaras; Gregory Jackson; Konstantinos Boulouchos

    2007-01-01

    The hetero-\\/homogeneous steady combustion and the stability limits of methane-fueled catalytic microreactors (Pt-coated) have been investigated numerically in a 1-mm-gap channel at pressures of 1 and 5bar. Computations were carried out with a full-elliptic two-dimensional model for the gas- and solid-phases that included elementary heterogeneous and homogeneous chemical reaction schemes, heat conduction in the solid wall, surface radiation heat transfer,

  8. Fate of fuel-sulfur in backmixed combustion systems. Final report, August 1979January 1980

    Microsoft Academic Search

    P. C. Malte; J. C. Kramlich; W. L. Grosshandler

    1980-01-01

    Comprehensive sulfur species measurements were performed on combustion gases in a premixed, jet-stirred reactor containing 0.23 mole % total sulfur. Species measured were HâS, COS, CSâ, CâHâS, SOâ, Oâ, CHâ, and CâHâ by gas chromatography; relative SH and CS and absolute OH by uv absorption spectroscopy; and SOâ by controlled condensation. Reactor fuels were CâHâ, CâHâ, CHâ, Hâ, and a

  9. What is the fate of CO2 produced by fossil fuel combustion?

    NSDL National Science Digital Library

    Paul Quay

    Students consider why the observed atmospheric CO2 increase rate is only ~60% of the CO2 loading rate due to fossil fuel combustion. They develop a box-model to simulate the atmospheric CO2 increase during the industrial era and compare it to the historic observations of atmospheric CO2 concentrations. The model is then used to forecast future concentrations of atmospheric CO2 during the next century.

  10. Dispersion of sound in a combustion duct by fuel droplets and soot particles

    NASA Technical Reports Server (NTRS)

    Miles, J. H.; Raftopoulos, D. D.

    1979-01-01

    Dispersion and attenuation of acoustic plane wave disturbances propagating in a ducted combustion system are studied. The dispersion and attenuation are caused by fuel droplet and soot emissions from a jet engine combustor. The attenuation and dispersion are due to heat transfer and mass transfer and viscous drag forces between the emissions and the ambient gas. Theoretical calculations show sound propagation at speeds below the isentropic speed of sound at low frequencies. Experimental results are in good agreement with the theory.

  11. Kinetic processes in the plasma formed in combustion of hydrocarbon fuels

    Microsoft Academic Search

    A. M. Starik; A. M. Savel’ev; N. S. Titova

    2011-01-01

    An analysis of the basic kinetic processes responsible for the formation of ions, electrons, charged and neutral carbon clusters\\u000a and particles of nanometer size in the combustion of hydrocarbon fuels has been made. It has been shown that the formation\\u000a of a polydisperse ensemble of positively and negatively charged particles is mainly caused by the ion adhesion to primary\\u000a particles

  12. Ash Deposit Formation and Deposit Properties. A Comprehensive Summary of Research Conducted at Sandia's Combustion Research Facility

    SciTech Connect

    Larry L. Baxter

    2000-08-01

    This report summarizes experimental and theoretical work performed at Sandia's Combustion Research Facility over the past eight years on the fate of inorganic material during coal combustion. This work has been done under four broad categories: coal characterization, fly ash formation, ash deposition, and deposit property development. The objective was to provide sufficient understanding of these four areas to be able to predict coal behavior in current and advanced conversion systems. This work has led to new characterization techniques for fuels that provide, for the first time, systematic and species specific information regarding the inorganic material. The transformations of inorganic material during combustion can be described in terms of the net effects of the transformations of these individual species. Deposit formation mechanisms provide a framework for predicting deposition rates for abroad range of particle sizes. Predictions based on these rates many times are quite accurate although there are important exceptions. A rigorous framework for evaluating deposit has been established. Substantial data have been obtained with which to exercise this framework, but this portion of the work is less mature than is any other. Accurate prediction of deposit properties as functions of fuel properties, boiler design, and boiler operating conditions represents the single most critical area where additional research is needed.

  13. Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

    1994-01-01

    An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide an engineering technology base for development of large scale hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed for conducting experimental investigations. Oxidizer (LOX or GOX) is injected through the head-end over a solid fuel (HTPB) surface. Experiments using fuels supplied by NASA designated industrial companies will also be conducted. The study focuses on the following areas: measurement and observation of solid fuel burning with LOX or GOX, correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study also being conducted at PSU.

  14. Accelerating the Computation of Detailed Chemical Reaction Kinetics for Simulating Combustion of Complex Fuels

    SciTech Connect

    Sankaran, R.; Grout, R.

    2012-01-01

    Combustion of hydrocarbon fuels has been a very challenging scientific and engineering problem due to the complexity of turbulent flows and hydrocarbon reaction kinetics. There is an urgent need to develop an efficient modeling capability to accurately predict the combustion of complex fuels. Detailed chemical kinetic models for the surrogates of fuels such as gasoline, diesel and JP-8 consist of thousands of chemical species and Arrhenius reaction steps. Oxygenated fuels such as bio-fuels and heavier hydrocarbons, such as from newer fossil fuel sources, are expected to have a much more complex chemistry requiring increasingly larger chemical kinetic models. Such models are beyond current computational capability, except for homogeneous or partially stirred reactor type calculations. The advent of highly parallel multi-core processors and graphical processing units (GPUs) promises a steep increase in computational performance in the coming years. This paper will present a software framework that translates the detailed chemical kinetic models to high-performance code targeted for GPU accelerators.

  15. Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels

    NASA Technical Reports Server (NTRS)

    Sherlock, T. P.

    1982-01-01

    Combustion tests of two scaled burners using actual coal gas from a 25 ton/day fluidized bed coal gasifier are described. The two combustor configurations studied were a ceramic lined, staged rich/lean burner and an integral, all metal multiannual swirl burner (MASB). The tests were conducted over a range of temperature and pressures representative of current industrial combustion turbine inlet conditions. Tests on the rich lean burner were conducted at three levels of product gas heating values: 104, 197 and 254 btu/scf. Corresponding levels of NOx emissions were 5, 20 and 70 ppmv. Nitrogen was added to the fuel in the form of ammonia, and conversion efficiencies of fuel nitrogen to NOx were on the order of 4 percent to 12 percent, which is somewhat lower than the 14 percent to 18 percent conversion efficiency when src-2 liquid fuel was used. The MASB was tested only on medium btu gas (220 to 270 btu/scf), and produced approximately 80 ppmv NOx at rated engine conditions. Both burners operated similarly on actual coal gas and erbs fuel, and all heating values tested can be successfully burned in current machines.

  16. LDA measurement of fuel droplet sizes and velocities in a combustion field

    SciTech Connect

    Kawazoe, H.; Ohsawa, K.; Fujikake, K. (Toyota Central Research and Development Laboratories, Inc., Nagakute-cho, Aichi-gun, Aichi-ken (JP))

    1990-11-01

    This paper reports on laser doppler anemometry applied to simultaneous measurement of fuel droplet size and its velocity in two kinds of continuous mini burners. Droplet size was determined from the scattered light intensity ({ital Ip}) and number of Doppler burst waves ({ital N}) that was required to correct the effect of different particle trajectories in the measuring volume. Prior to the experiments, calibrated lines for representative droplet diameters were made with regard to {ital Ip} and {ital N}. The two burners had different types of air assist fuel injectors. One had the injector with the swirler which provides assist air with a tangential velocity component. Another had the injector without the swirler and the air had no tangential component. These combustion flow fields were then compared. Downstream of the injector in both burners, Sauter mean diameter (SMD) varies as follows. In a combustion field it is larger than that in unburned condition and reaches a maximum, after which it decreases until all the droplet evaporate rapidly. These features agree with the results of numerical calculations for fuel droplet evaporation. In combustion fields, the SMD of the droplets from the swirler injector is about 10 {mu}m smaller than that from the no-swirler injector. Therefore the droplets evaporate earlier than those from the no-swirler injector in the burner.

  17. Analysis of the combustion of sewage sludge-derived fuel by a thermogravimetric method in China.

    PubMed

    Jiang, Jianguo; Du, Xuejuan; Yang, Shihui

    2010-07-01

    The treatment and disposal of sewage sludge are significant environmental problems in China. The reuse of sewage sludge for fuel could be an effective solution. The aim of this study was to characterize the behavior of sludge-derived fuel during combustion by a thermogravimetric method. The combustion profiles obtained showed four obvious weight loss regions. The results of dynamics analysis showed that first-order reactions together with Arrhenius' law explained reasonably well the different stages of weight loss in the samples. Three temperature regions (162-327 degrees C, 367-445 degrees C, and 559-653 degrees C for sawdust and 162-286 degrees C, 343-532 degrees C, and 609-653 degrees C for coal) in each derivative thermogravimetry (DTG) curve corresponded well with the Arrhenius equation. The reactivity of sludge was lower than that of samples containing sawdust, but higher than that of coal-containing samples. These data demonstrate that sludge-derived fuel has better combustion characteristics than sludge, sawdust, or coal. PMID:20356726

  18. The response of fuel injector sprays to acoustic perturbation and their role in combustion instability

    Microsoft Academic Search

    MC Jerm; WG Doherty; DA Greenhalgh

    Self-excited thermo-acoustic instabilities (sometimes known as rumble) have impeded the development of lean burn low NOx gas turbine combustors. Acoustic waves in the combustor interact with the fuel\\/air mixing process to modulate fuel field properties e.g. air-fuel ratio (AFR). The fluctuating fuel field properties cause the heat release rate to fluctuate. If the Rayleigh criterion is obeyed i.e. the phase

  19. Identification and quantification analysis of nonlinear dynamics properties of combustion instability in a diesel engine

    NASA Astrophysics Data System (ADS)

    Yang, Li-Ping; Ding, Shun-Liang; Litak, Grzegorz; Song, En-Zhe; Ma, Xiu-Zhen

    2015-01-01

    The cycling combustion instabilities in a diesel engine have been analyzed based on chaos theory. The objective was to investigate the dynamical characteristics of combustion in diesel engine. In this study, experiments were performed under the entire operating range of a diesel engine (the engine speed was changed from 600 to 1400 rpm and the engine load rate was from 0% to 100%), and acquired real-time series of in-cylinder combustion pressure using a piezoelectric transducer installed on the cylinder head. Several methods were applied to identify and quantitatively analyze the combustion process complexity in the diesel engine including delay-coordinate embedding, recurrence plot (RP), Recurrence Quantification Analysis, correlation dimension (CD), and the largest Lyapunov exponent (LLE) estimation. The results show that the combustion process exhibits some determinism. If LLE is positive, then the combustion system has a fractal dimension and CD is no more than 1.6 and within the diesel engine operating range. We have concluded that the combustion system of diesel engine is a low-dimensional chaotic system and the maximum values of CD and LLE occur at the lowest engine speed and load. This means that combustion system is more complex and sensitive to initial conditions and that poor combustion quality leads to the decrease of fuel economy and the increase of exhaust emissions.

  20. Identification and quantification analysis of nonlinear dynamics properties of combustion instability in a diesel engine.

    PubMed

    Yang, Li-Ping; Ding, Shun-Liang; Litak, Grzegorz; Song, En-Zhe; Ma, Xiu-Zhen

    2015-01-01

    The cycling combustion instabilities in a diesel engine have been analyzed based on chaos theory. The objective was to investigate the dynamical characteristics of combustion in diesel engine. In this study, experiments were performed under the entire operating range of a diesel engine (the engine speed was changed from 600 to 1400?rpm and the engine load rate was from 0% to 100%), and acquired real-time series of in-cylinder combustion pressure using a piezoelectric transducer installed on the cylinder head. Several methods were applied to identify and quantitatively analyze the combustion process complexity in the diesel engine including delay-coordinate embedding, recurrence plot (RP), Recurrence Quantification Analysis, correlation dimension (CD), and the largest Lyapunov exponent (LLE) estimation. The results show that the combustion process exhibits some determinism. If LLE is positive, then the combustion system has a fractal dimension and CD is no more than 1.6 and within the diesel engine operating range. We have concluded that the combustion system of diesel engine is a low-dimensional chaotic system and the maximum values of CD and LLE occur at the lowest engine speed and load. This means that combustion system is more complex and sensitive to initial conditions and that poor combustion quality leads to the decrease of fuel economy and the increase of exhaust emissions. PMID:25637916

  1. Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

    PubMed

    Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

    2015-02-01

    The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions. PMID:25582882

  2. Recent trends in aviation turbine fuel properties

    NASA Technical Reports Server (NTRS)

    Friedman, R.

    1982-01-01

    Plots and tables, compiled from Department of Energy (and predecessor agency) inspection reports from 1969 to 1980, present ranges, averages, extremes, and trends for most of the 22 properties of Jet A aviation turbine fuel. In recent years, average values of aromatics content, mercaptan sulfur content, distillation temperature of 10 percent recovered, smoke point, and freezing point show small but recognizable trends toward their specification limits. About 80 percent of the fuel samples had at least one property near specification, defined as within a standard band about the specification limit. By far the most common near-specification properties were aromatics content, smoke point, and freezing point.

  3. Fluidized bed combustion of pelletized biomass and waste-derived fuels

    SciTech Connect

    Chirone, R.; Scala, F.; Solimene, R. [Istituto di Ricerche sulla Combustione - C.N.R., Piazzale V. Tecchio 80, 80125 Naples (Italy); Salatino, P.; Urciuolo, M. [Dipartimento di Ingegneria Chimica - Universita degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Naples (Italy)

    2008-10-15

    The fluidized bed combustion of three pelletized biogenic fuels (sewage sludge, wood, and straw) has been investigated with a combination of experimental techniques. The fuels have been characterized from the standpoints of patterns and rates of fuel devolatilization and char burnout, extent of attrition and fragmentation, and their relevance to the fuel particle size distribution and the amount and size distribution of primary ash particles. Results highlight differences and similarities among the three fuels tested. The fuels were all characterized by limited primary fragmentation and relatively long devolatilization times, as compared with the time scale of particle dispersion away from the fuel feeding ports in practical FBC. Both features are favorable to effective lateral distribution of volatile matter across the combustor cross section. The three fuels exhibited distinctively different char conversion patterns. The high-ash pelletized sludge burned according to the shrinking core conversion pattern with negligible occurrence of secondary fragmentation. The low-ash pelletized wood burned according to the shrinking particle conversion pattern with extensive occurrence of secondary fragmentation. The medium-ash pelletized straw yielded char particles with a hollow structure, resembling big cenospheres, characterized by a coherent inorganic outer layer strong enough to prevent particle fragmentation. Inert bed particles were permanently attached to the hollow pellets as they were incorporated into ash melts. Carbon elutriation rates were very small for all the fuels tested. For pelletized sludge and straw, this was mostly due to the shielding effect of the coherent ash skeleton. For the wood pellet, carbon attrition was extensive, but was largely counterbalanced by effective afterburning due to the large intrinsic reactivity of attrited char fines. The impact of carbon attrition on combustion efficiency was negligible for all the fuels tested. The size distribution of primary ash particles liberated upon complete carbon burnoff largely reflected the combustion pattern of each fuel. Primary ash particles of size nearly equal to that of the parent fuel were generated upon complete burnoff of the pelletized sludge. Nonetheless, secondary attrition of primary ash from pelletized sludge is large, to the point where generation of fine ash would be extensive over the typical residence time of bed ash in fluidized bed combustors. Very few and relatively fine primary ash particles were released after complete burnoff of wood pellets. Primary ash particles remaining after complete burnoff of pelletized straw had sizes and shapes that were largely controlled by the occurrence of ash agglomeration phenomena. (author)

  4. Effect of fuel properties on the first cycle fuel delivery in a Port Fuel Injected Spark Ignition Engine

    E-print Network

    Lang, Kevin R., 1980-

    2004-01-01

    Achieving robust combustion while also yielding low hydrocarbon (HC) emissions is difficult for the first cycle of cranking during the cold start of a Port Fuel Injected (PFI) Spark Ignition (SI) engine. Cold intake port ...

  5. Methods and systems to thermally protect fuel nozzles in combustion systems

    DOEpatents

    Helmick, David Andrew; Johnson, Thomas Edward; York, William David; Lacy, Benjamin Paul

    2013-12-17

    A method of assembling a gas turbine engine is provided. The method includes coupling a combustor in flow communication with a compressor such that the combustor receives at least some of the air discharged by the compressor. A fuel nozzle assembly is coupled to the combustor and includes at least one fuel nozzle that includes a plurality of interior surfaces, wherein a thermal barrier coating is applied across at least one of the plurality of interior surfaces to facilitate shielding the interior surfaces from combustion gases.

  6. Method of regulating the amount of underfire air for combustion of wood fuels in spreader-stroke boilers

    DOEpatents

    Tuttle, Kenneth L. (Federal Way, WA)

    1980-01-01

    A method of metering underfire air for increasing efficiency and reducing particulate emissions from wood-fire, spreader-stoker boilers is disclosed. A portion of the combustion air, approximately one pound of air per pound of wood, is fed through the grate into the fuel bed, while the remainder of the combustion air is distributed above the fuel in the furnace, and the fuel bed is maintained at a depth sufficient to consume all oxygen admitted under fire and to insure a continuous layer of fresh fuel thereover to entrap charred particles inside the fuel bed.

  7. Design and implementation of Carbon Monoxide and Oxygen emissions measurement in swirl-stabilized oxy-fuel combustion

    E-print Network

    Sommer, Andrew (Andrew Zhang)

    2013-01-01

    Oxy-fuel combustion in natural gas power generation is a technology of growing interest as it provides the most efficient means of carbon capture. Since all the emissions from these power plants are sequestered, there are ...

  8. Improvement of jet fuel properties by paraffin isomerization

    Microsoft Academic Search

    A. G. Oblad; J. Shabtai; E. N. Coppola

    1987-01-01

    The quality of jet fuels could be significantly improved if long-chain n-paraffins present as components in such fuels are subjected to skeletal hydroisomerization into branched paraffins. The reduced surface tension and viscosity of hydroisomerized products can be expected to improve atomization and combustion, while reduced freezing point could allow the use of broader boiling fuel distillates. This paper summarizes results

  9. Wood fuel for power generation at Wendel, California. Volume 4. Fuel properties

    SciTech Connect

    Not Available

    1981-05-01

    Wood materials available from within the 100-mile Susanville procurement area for fueling the Honey Lake hybrid power plant are studied, treating (a) heating values, (b) drying characteristics, (c) soil-rock contamination, (d) storage degradation, and (e) combustion emissions.

  10. Combustion-derived nanoparticle exposure and household solid fuel use in Xuanwei and Fuyuan, China

    PubMed Central

    Hosgood, H. Dean; Lan, Qing; Vermeulen, Roel; Wei, Hu; Reiss, Boris; Coble, Joseph; Wei, Fusheng; Jun, Xu; Wu, Guoping; Rothman, Nat

    2014-01-01

    Combustion-derived nanoparticles (CDNPs) have not been readably measurable until recently. We conducted a pilot study to determine CDNP levels during solid fuel burning. The aggregate surface area of CDNP (?m2/cm3) was monitored continuously in 15 Chinese homes using varying fuel types (i.e. bituminous coal, anthracite coal, wood) and stove types (i.e. portable stoves, stoves with chimneys, firepits). Information on fuel burning activities was collected and PM2.5 levels were measured. Substantial exposure differences were observed during solid fuel burning (mean: 228.1 ?m2/cm3) compared to times without combustion (mean: 14.0 ?m2/cm3). The observed levels during burning were reduced by about four-fold in homes with a chimney (mean: 92.1 ?m2/cm3; n = 9), and effects were present for all fuel types. Each home’s CDNP measurement was only moderately correlated with the respective PM2.5 measurements (r2 = 0.43; p = 0.11). Our results indicate that household coal and wood burning contributes to indoor nanoparticle levels, which are not fully reflected in PM2.5 measurements. PMID:22639822

  11. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R. [NETL

    2013-03-11

    The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

  12. Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon [ORNL] [ORNL; Curran, Scott [ORNL] [ORNL; Prikhodko, Vitaly Y [ORNL] [ORNL; Sluder, Scott [ORNL] [ORNL; Parks, II, James E [ORNL; Wagner, Robert M [ORNL] [ORNL

    2011-01-01

    An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas recirculation (EGR). However, high carbon monoxide (CO) and hydrocarbon (HC) emissions were observed. The low combustion gas temperature during the expansion and exhaust processes seemed to be the dominant source of high CO emissions in the RCCI combustion mode. The high HC emissions during the RCCI combustion mode could be due to the increased combustion quenching layer thickness as well as the -stratification at the periphery of the combustion chamber. The slightly higher brake thermal efficiency (BTE) of the RCCI combustion mode was observed than the other combustion modes, such as the conventional diesel combustion (CDC) mode, and single-fuel, premixed charge compression ignition (PCCI) combustion mode. The parametric study of the RCCI combustion mode revealed that the combustion phasing and/or the peak cylinder pressure rise rate of the RCCI combustion mode could be controlled by several physical parameters premixed ratio (rp), intake swirl intensity, and start of injection (SOI) timing of directly injected fuel unlike other low temperature combustion (LTC) strategies.

  13. Fuel supply control method for internal combustion engines, with adaptability to various engines and controls therefor having different operating characteristics

    Microsoft Academic Search

    Y. Otobe; M. Chikamatsu

    1988-01-01

    A method of controlling the fuel supply to an internal combustion engine is described, wherein a quantity of fuel for supply to the engine is determined by correcting a basic value of the quantity of fuel determined as a function of at least one operating parameter of the engine by correction values dependent upon operating conditions of the engine and

  14. Aerodynamic drag and fuel spreading measurements in a simulated scramjet combustion module

    NASA Technical Reports Server (NTRS)

    Povinelli, L. A.

    1974-01-01

    The drag of a simulated scramjet combustion module was measured at Mach 2, 2.5, and 3. The combustor was rectangular in cross section and incorporated six swept fuel injector struts. The effect of strut leading edge radius, position of maximum thickness, thickness ratio, sweep angle, and strut length on the drag was determined. Reduction in thickness ratio had the largest effect on drag reduction. Sweeping the struts upstream yielded the same drag as sweeping the struts downstream and potentially offers the advantages of increased mixing time for the fuel. Helium injection was used to simulate hydrogen fuel. The interstrut spacing required to achieve good distribution of fuel was was found to be about 10 jet diameters. The contribution of helium injection to drag reduction was small.

  15. Nitrogen oxides, sulfur trioxide, and mercury emissions during oxy-fuel fluidized bed combustion of Victorian brown coal.

    PubMed

    Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

    2014-12-16

    This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal. PMID:25402169

  16. Co-Combustion of Refuse Derived Fuel with Anthracites in a CFB Boiler

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Won; Lee, Jong-Min; Kim, Jae-Sung

    Combustion of Refuse derived fuel (RDF) is considered as a priority solution to energy recovery from municipal solid waste (MSW). The co-combustion characteristics of anthracite coals with RDF were determined in the commercial scale Tonghae CFB Power Plant. As the feeding ratio of the RDF to the anthracites increased to 5%, temperature and pressure were not changed in comparison with firing only anthracites. The amount of the required air was reduced due to high O2 content in RDF relative to the anthracites. The emissions of NOx, SOx, HCl and Dioxin were also measured. According to higher mixing ratio of the RDF to the anthracites, SOx, NOx emissions slightly decreased and HCl emissions increased, because RDF has relatively smaller S, N and higher CI than the anthracites. Heavy metals of the fly ash and bottom ash and the dioxin emissions were far below Korean maximum permissible concentration level at incinerator. The results showed that it is of great use and technically possible to co-combustion of RDF with the anthracites by 5% in the form of fuel recovery and energy production in commercial scale CFB boiler.

  17. Reducing NOx emissions from a biodiesel-fueled engine by use of low-temperature combustion.

    PubMed

    Fang, Tiegang; Lin, Yuan-Chung; Foong, Tien Mun; Lee, Chia-Fon

    2008-12-01

    Biodiesel is popularly discussed in many countries due to increased environmental awareness and the limited supply of petroleum. One of the main factors impacting general replacement of diesel by biodiesel is NOx (nitrogen oxides) emissions. Previous studies have shown higher NOx emissions relative to petroleum diesel in traditional direct-injection (DI) diesel engines. In this study, effects of injection timing and different biodiesel blends are studied for low load [2 bar IMEP (indicated mean effective pressure)] conditions. The results show that maximum heat release rate can be reduced by retarding fuel injection. Ignition and peak heat release rate are both delayed for fuels containing more biodiesel. Retarding the injection to post-TDC (top dead center) lowers the peak heat release and flattens the heat release curve. It is observed that low-temperature combustion effectively reduces NOx emissions because less thermal NOx is formed. Although biodiesel combustion produces more NOx for both conventional and late-injection strategies, with the latter leading to a low-temperature combustion mode, the levels of NOx of B20 (20 vol % soy biodiesel and 80 vol % European low-sulfur diesel), B50, and B100 all with post-TDC injection are 68.1%, 66.7%, and 64.4%, respectively, lower than pure European low-sulfur diesel in the conventional injection scenario. PMID:19192810

  18. Cold start fuel management of port-fuel-injected internal combustion engines

    E-print Network

    Cuseo, James M. (James Michael)

    2005-01-01

    The purpose of this study is to investigate how changes in fueling strategy in the second cycle of engine operation influence the delivered charge fuel mass and engine out hydrocarbon (EOHC) emissions in that and subsequent ...

  19. Fuel decomposition and boundary-layer combustion processes of hybrid rocket motors

    NASA Technical Reports Server (NTRS)

    Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

    1995-01-01

    Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated Polybutadiene) fuel cross-linked with diisocyanate was burned with GOX under various operating conditions. Large-amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed-line system and combustion chamber, the pressure oscillations were drastically reduced from +/-20% of the localized mean pressure to an acceptable range of +/-1.5% Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations are thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real-time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thickness burned and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented.

  20. Laboratory characterization of PM emissions from combustion of wildland biomass fuels

    NASA Astrophysics Data System (ADS)

    Hosseini, S.; Urbanski, S. P.; Dixit, P.; Qi, L.; Burling, I. R.; Yokelson, R. J.; Johnson, T. J.; Shrivastava, M.; Jung, H. S.; Weise, D. R.; Miller, J. W.; Cocker, D. R.

    2013-09-01

    Particle emissions from open burning of southwestern (SW) and southeastern (SE) U.S. fuel types during 77 controlled laboratory burns are presented. The fuels include SW vegetation types: ceanothus, chamise/scrub oak, coastal sage scrub, California sagebrush, manzanita, maritime chaparral, masticated mesquite, oak savanna, and oak woodland, as well as SE vegetation types: 1 year, 2 year rough, pocosin, chipped understory, understory hardwood, and pine litter. The SW fuels burned at higher modified combustion efficiency (MCE) than the SE fuels resulting in lower particulate matter mass emission factor. Particle mass distributions for six fuels and particle number emission for all fuels are reported. Excellent mass closure (slope = 1.00, r2 = 0.94) between ions, metals, and carbon with total weight was obtained. Organic carbon emission factors inversely correlated (R2 = 0.72) with average MCE, while elemental carbon (EC) had little correlation with average MCE (R2 = 0.10). The EC/total carbon ratio sharply increased with MCE for MCEs exceeding 0.94. The average levoglucosan and total polycyclic aromatic hydrocarbon (PAH) emissions factors ranged from 25 to 1272 mg/kg fuel and 1.8 to 11.3 mg/kg fuel, respectively. No correlation between average MCE and emissions of PAHs/levoglucosan was found. Additionally, PAH diagnostic ratios were observed to be poor indicators of biomass burning. Large fuel type and regional dependency were observed in the emission rates of ammonium, nitrate, chloride, sodium, and potassium.

  1. Combustion chamber for internal combustion engine

    Microsoft Academic Search

    Isida

    1988-01-01

    This patent describes a combustion chamber for an internal combustion engine, comprising: a main combustion chamber hollowed out of the top of a piston; a subsidiary combustion chamber hollowed out of the piston top, the subsidiary combustion chamber communicating with and disposed in side by side relationship to the main combustion chamber; a fuel injection nozzle located generally between the

  2. Greenhouse impact due to the use of combustible fuels: Life cycle viewpoint and relative radiative forcing commitment

    SciTech Connect

    Kirkinen, J.; Palosuo, T.; Holmgren, K.; Savolainen, I. [VTT Technical Research Center Finland, Espoo (Finland)

    2008-09-15

    Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels.

  3. Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment

    PubMed Central

    Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

    2008-01-01

    Extensive information on the greenhouse impacts of various human actions is important in developing effective climate change mitigation strategies. The greenhouse impacts of combustible fuels consist not only of combustion emissions but also of emissions from the fuel production chain and possible effects on the ecosystem carbon storages. It is important to be able to assess the combined, total effect of these different emissions and to express the results in a comprehensive way. In this study, a new concept called relative radiative forcing commitment (RRFC) is presented and applied to depict the greenhouse impact of some combustible fuels currently used in Finland. RRFC is a ratio that accounts for the energy absorbed in the Earth system due to changes in greenhouse gas concentrations (production and combustion of fuel) compared to the energy released in the combustion of fuel. RRFC can also be expressed as a function of time in order to give a dynamic cumulative picture on the caused effect. Varying time horizons can be studied separately, as is the case when studying the effects of different climate policies on varying time scales. The RRFC for coal for 100 years is about 170, which means that in 100 years 170 times more energy is absorbed in the atmosphere due to the emissions of coal combustion activity than is released in combustion itself. RRFC values of the other studied fuel production chains varied from about 30 (forest residues fuel) to 190 (peat fuel) for the 100-year study period. The length of the studied time horizon had an impact on the RRFC values and, to some extent, on the relative positions of various fuels. PMID:18521657

  4. The influence of oxygen concentration on the combustion of a fuel/oxidizer mixture

    SciTech Connect

    Biteau, H. [School of Engineering and Electronics, BRE Centre for Fire Safety Engineering, The University of Edinburgh, Edinburgh EH9 3JL (United Kingdom); Institut National de l'Environnement Industriel et des Risques, Parc Technologique Alata, Verneuil en Halatte (France); Fuentes, A. [Institut Universitaire des Systemes Thermiques Industriels (CNRS UMR 6595), Universite de Provence, 13453 Marseille Cedex 13 (France); Marlair, G. [Institut National de l'Environnement Industriel et des Risques, Parc Technologique Alata, Verneuil en Halatte (France); Torero, J.L. [School of Engineering and Electronics, BRE Centre for Fire Safety Engineering, The University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

    2010-04-15

    The aim of the present study is to investigate the influence of the O{sub 2} concentration on the combustion behaviour of a fuel/oxidizer mixture. The material tested is a ternary mixture of lactose, starch, and potassium nitrate, which has already been used in an attempt to estimate heat release rate using the FM-Global Fire Propagation Apparatus. It provides a well-controlled combustion chamber to study the evolution of the combustion products when varying the O{sub 2} concentration, between air and low oxidizer conditions. Different chemical behaviours have been exhibited. When the O{sub 2} concentration was reduced beyond 18%, large variations were observed in the CO{sub 2} and CO concentrations. This critical O{sub 2} concentration seems to be the limit before which the material only uses its own oxidizer to react. On the other hand, mass loss did not highlight this change in chemical reactions and remained similar whatever the test conditions. This presumes that the oxidation of CO into CO{sub 2} are due to reactions occurring in the gas phase especially for large O{sub 2} concentrations. This actual behaviour can be verified using a simplified flammability limit model adapted for the current work. Finally, a sensitivity analysis has been carried out to underline the influence of CO concentration in the evaluation of heat release rate using typical calorimetric methods. The results of this study provide a critical basis for the investigation of the combustion of a fuel/oxidizer mixture and for the validation of future numerical models. (author)

  5. Potential hazards associated with combustion of bio-derived versus petroleum-derived diesel fuel

    PubMed Central

    Bünger, Jürgen; Krahl, Jürgen; Schröder, Olaf; Schmidt, Lasse; Westphal, Götz A.

    2012-01-01

    Fuels from renewable resources have gained worldwide interest due to limited fossil oil sources and the possible reduction of atmospheric greenhouse gas. One of these fuels is so called biodiesel produced from vegetable oil by transesterification into fatty acid methyl esters (FAME). To get a first insight into changes of health hazards from diesel engine emissions (DEE) by use of biodiesel scientific studies were reviewed which compared the combustion of FAME with common diesel fuel (DF) for legally regulated and non-regulated emissions as well as for toxic effects. A total number of 62 publications on chemical analyses of DEE and 18 toxicological in vitro studies were identified meeting the criteria. In addition, a very small number of human studies and animal experiments were available. In most studies, combustion of biodiesel reduces legally regulated emissions of carbon monoxide, hydrocarbons, and particulate matter. Nitrogen oxides are regularly increased. Among the non-regulated emissions aldehydes are increased, while polycyclic aromatic hydrocarbons are lowered. Most biological in vitro assays show a stronger cytotoxicity of biodiesel exhaust and the animal experiments reveal stronger irritant effects. Both findings are possibly caused by the higher content of nitrogen oxides and aldehydes in biodiesel exhaust. The lower content of PAH is reflected by a weaker mutagenicity compared to DF exhaust. However, recent studies show a very low mutagenicity of DF exhaust as well, probably caused by elimination of sulfur in present DF qualities and the use of new technology diesel engines. Combustion of vegetable oil (VO) in common diesel engines causes a strongly enhanced mutagenicity of the exhaust despite nearly unchanged regulated emissions. The newly developed fuel “hydrotreated vegetable oil” (HVO) seems to be promising. HVO has physical and chemical advantages compared to FAME. Preliminary results show lower regulated and non-regulated emissions and a decreased mutagenicity. PMID:22871157

  6. Combustion of fuel with high fines in Ahlstrom Pyroflow{reg_sign} CFB boilers

    SciTech Connect

    Chelian, P.K.; Gamble, R. [Pyropower Corp., San Diego, CA (United States)

    1995-12-31

    Ahlstrom Pyroflow{reg_sign} boilers have demonstrated the ability of circulating fluidized bed (CFB) boilers to successfully burn unconventional fuels. These boilers have played a major role in the utilization of waste fuels, like bituminous gob and anthracite culm. Many of the waste fuels are processed prior to combustion to increase their heating value. As the technology for combustion of these fuels advanced, so has the desire of the owners to utilize more of the waste fuel and minimize the rejects. In the past, a majority of the fines content (less than 150 microns) was rejected and returned to the piles along with other rejects. In some cases, pond settlings were found to have a reasonably useful heat content, and were a preferred supplement to the anthracite culm. The use of these rejects had one result in common, i.e., to increase the fines content in the fuel feed to the CFB boilers. Pyropower was involved in tests conducted at two boilers, one burning bituminous gob and the other burning processed anthracite culm and silt. These tests were aimed at studying the effect of the high fuel fines content on the CFB boiler performance to determine the maximum practical fines limit. There were concerns of high unburned carbon loss, high CO and high cyclone temperatures. The actual test data confirmed that these boilers could fire a high percent of fines without major concerns. This paper discusses in detail the results of the testing with anthracite culm and silt, and references similar observations made during the testing with high fines bituminous gob.

  7. The origin and fate of organic pollutants from the combustion of alternative fuels

    SciTech Connect

    NONE

    1995-06-01

    The overall objective of this project is to determine the impact of alternative fuels on air quality, particularly ozone formation. The objective will be met through three steps: (1) qualitative identification of alternative fuel combustion products, (2) quantitative measurement of specific emission levels of these products, and (3) determination of the fate of the combustion products in the atmosphere. The alternative fuels of interest are methanol, ethanol, natural gas, and LP gas. The role of the University of Dayton Research Institute (UDRI) in this project is two-fold. First, fused silica flow reactor instrumentation is being used to obtain both qualitative identification and quantitative data on the thermal degradation products from the fuel-lean (oxidative), stoichiometric, and fuel-rich (pyrolytic) decomposition of methanol, ethanol, liquefied petroleum gas, and natural gas. Secondly, a laser photolysis/laser-induced fluorescence (LP/LIF) apparatus is being used to determine the rates and mechanisms of reaction of selected degradation products under atmospheric conditions. This draft final report contains the results of the second year of the study. The authors initially discuss the results of their flow reactor studies. This is followed by a discussion of the initial results from their LP/LIF studies of the reaction of hydroxyl (OH) radicals with methanol and ethanol. In the coming year, they plan to obtain quantitative data on the oxidation of methyl-t-butyl-ether and reformulated gasoline under fuel-lean, stoichiometric, and fuel-rich conditions. They also plan to conduct a mechanistic analysis of the reaction of OH with acetaldehyde and formaldehyde over an extended temperature range.

  8. Computations of spray, fuel-air mixing, and combustion in a lean-premixed-prevaporized combustor

    NASA Technical Reports Server (NTRS)

    Dasgupta, A.; Li, Z.; Shih, T. I.-P.; Kundu, K.; Deur, J. M.

    1993-01-01

    A code was developed for computing the multidimensional flow, spray, combustion, and pollutant formation inside gas turbine combustors. The code developed is based on a Lagrangian-Eulerian formulation and utilizes an implicit finite-volume method. The focus of this paper is on the spray part of the code (both formulation and algorithm), and a number of issues related to the computation of sprays and fuel-air mixing in a lean-premixed-prevaporized combustor. The issues addressed include: (1) how grid spacings affect the diffusion of evaporated fuel, and (2) how spurious modes can arise through modelling of the spray in the Lagrangian computations. An upwind interpolation scheme is proposed to account for some effects of grid spacing on the artificial diffusion of the evaporated fuel. Also, some guidelines are presented to minimize errors associated with the spurious modes.

  9. Electrochemical Sensing of Dopamine and Antibacterial Properties of ZnO Nanoparticles Synthesized from Solution Combustion Method

    NASA Astrophysics Data System (ADS)

    Manjunath, K.; Lingaraju, K.; Kumar, D.; Nagabhushan, H.; Samrat, D.; Reddy, V.; Dupont, J.; Ramakrishnappa, T.; Nagaraju, G.

    2015-03-01

    We have successfully synthesized ZnO nanoparticles (NPs) from solution combustion method using combustible fuel (Green gram). XRD pattern confirms that the prepared compound is composed of wurtzite hexagonal zinc-oxide. FTIR spectrum of ZnO NPs shows the band at 417 cm-1 associated with the characteristic vibration of Zn-O. The UV-Vis spectrum shows a strong absorption band at 365 nm which is blue shifted due to quantum confinement effect. TEM images show the average sizes of the nanoparticles are found to be almost 15-30 nm. The as-synthesized product shows good electrochemical sensing of dopamine. Furthermore the antibacterial properties of ZnO NPs were investigated by their bactericidal activity against four bacterial strains using the agar well diffusion method.

  10. Pulverized-fuel combustion: modeling and scaleup methodologies. Second quarterly report, January 1, 1981-March 31, 1981

    SciTech Connect

    Lewis, P F; Wolf, T L; Gelb, A; Pugh, E

    1981-05-01

    Most of the effort was devoted to the model element improvement in four areas: Chemical reactions of OH and O radicals with carbon surfaces; effect of particle size distribution on optical absorption properties of the coal feed; dynamics of a distribution of particle sizes; and development of scaling laws for the location and shape of recirculation zone boundaries. The conclusions from these efforts are: 1) the chemical reactions of OH and O radicals with carbon surfaces are very rapid at combustion temperature. The reactions are first order in total pressure and yield CO as the primary product. Optical absorption coefficients of Rosin-Rammler distributions of typical pulverized fuel are about three times the value for mass mean particle size. The model will include the optical absorption coefficient appropriate for the size distribution within the combustor. The particle size distribution has a significant effect on the particle velocity distribution and thus on residence times of the larger particles. Calculations of particle dynamics are underway. An exhaust search was conducted for literature related to flow patterns in axisymmetric, confined, combusting flows, both with and without swirl. Correlation of various experimental results was attempted.

  11. The Assessment of Fracture Geometrical Properties on the Performance of Conventional In Situ Combustion

    Microsoft Academic Search

    S. M. Fatemi; R. Kharrat; C. Ghotbi

    2011-01-01

    The aim of the present work is to evaluate the effect of fractures geometrical properties such as orientation, density, location, and networking on the conventional fire flooding (CFF) process performance through simulation analysis. Combustion parameters of a fractured low-permeable carbonate heavy oil reservoir in Iran called Kuh-E-Mond (KEM); applied for simulation study and simulator has been validated with KEM combustion

  12. Investigation of Sooting in Microgravity Droplet Combustion: Fuel-Dependent Effects

    NASA Technical Reports Server (NTRS)

    Manzello, Samuel L.; Hua, Ming; Choi, Mun Young

    1999-01-01

    Kumagai and coworkers first performed microgravity droplet combustion experiments [Kumagai, 1957]. The primary goal of these early experiments were to validate simple 'd(sup 2)-law models [Spalding, 1954, Godsave, 1954] Inherent in the 'd(sup 2) -law' formulation and in the scope of the experimental observation is the neglect of sooting behavior. In fact, the influence of sooting has not received much attention until more recent works [Choi et al., 1990; Jackson et al., 1991; Jackson and Avedisian, 1994; Choi and Lee, 1996; Jackson and Avedisian, 1996; Lee et al., 1998]:. Choi and Lee measured soot volume fraction for microgravity droplet flames using full-field light extinction and subsequent tomographic inversion [Choi and Lee, 1996]. In this investigation, soot concentrations were measured for heptane droplets and it was reported that soot concentrations were considerably higher in microgravity compared to the normal gravity flame. It was reasoned that the absence of buoyancy and the effects of thermophoresis resulted in the higher soot concentrations. Lee et al. [1998] performed soot measurement experiments by varying the initial droplet diameter and found marked influence of sooting on the droplet burning behavior. There is growing sentiment that sooting in droplet combustion must no longer be neglected and that "perhaps one of the most important outstanding contributions of (micro)g droplet combustion is the observation that in the absence of asymmetrical forced and natural convection, a soot shell is formed between the droplet surface and the flame, exerting an influence on the droplet combustion response far greater than previously recognized." [Law and Faeth, 1994]. One of the methods that we are exploring to control the degree of sooting in microgravity is to use different fuels. The effect of fuel structure on sooting propensity has been investigated for over-ventilated concentric coflowing buoyant diffusion flames. (Glassman, 1996]. In these investigations, the fuel flowrate was increased until smoke was observed to escape from the "luminous visible flame" [Glassman, 1996]. A total of 29 fuels were used in order to characterize relative sooting propensity. The sooting propensity of a particular fuel was assessed by comparing the flowrates for soot emission from the tip of the flame. It was reported that the sooting tendency for diffusion flames increased for fuels with higher rates of pyrolysis. Randolph and Law [1986 and not 1994] also examined the effect of fuel structure on droplet sooting behavior. In their experiments the droplets were separated from the bulk gas stream and quenched with nitrogen prior to gravimetric measurements. A variety of fuels were studied, namely aromatics, phenyl-alkanes and alkanes. The results were in qualitative agreement with the work of Glassman [1986]. Vander Wal et al. [1994] performed relative soot concentration measurements using laser-induced incandescence for heptane and decane fuel droplets burning under normal-gravity conditions. It was found that soot volume fractions for decane was more than a factor of two larger than that for heptane. Although the normal-gravity investigations have provided some important insights regarding the influence of fuel structure on the sooting behavior of droplet flames, results cannot be easily extrapolated for microgravity studies since increased residence times and thermophoretic effects must be considered in greater detail. Several studies have compared sooting behavior of different fuel droplets burning under microgravity conditions [Card and Choi, 1990; Jackson et al., 1991; Jackson and Avedisian, 1994], however, detailed quantitative results were not provided. In all of these previous studies, the degree of sooting was only visually assessed from an incandescent backlighted image of the soot containing region. Such techniques can provide misleading results regarding sooting behavior [Choi, 1996].

  13. Thermophysics Characterization of Kerosene Combustion

    NASA Technical Reports Server (NTRS)

    Wang, Ten-See

    2001-01-01

    A one-formula surrogate fuel formulation and its quasi-global combustion kinetics model are developed to support the design of injectors and thrust chambers of kerosene-fueled rocket engines. This surrogate fuel model depicts a fuel blend that properly represents the general physical and chemical properties of kerosene. The accompanying gaseous-phase thermodynamics of the surrogate fuel is anchored with the heat of formation of kerosene and verified by comparing a series of one-dimensional rocket thrust chamber calculations. The quasi-global combustion kinetics model consists of several global steps for parent fuel decomposition, soot formation, and soot oxidation and a detailed wet-CO mechanism to complete the combustion process. The final thermophysics formulations are incorporated with a computational fluid dynamics model for prediction of the combustion efficiency of an unielement, tripropellant combustor and the radiation of a kerosene-fueled thruster plume. The model predictions agreed reasonably well with those of the tests.

  14. Hydrocarbon-fuel/combustion-chamber-liner materials compatibility. Interim final report, 7 November 1986-31 October 1989

    SciTech Connect

    Gage, M.L.

    1990-04-01

    Results of material compatibility experiments using hydrocarbon fuels in contact with copper-based combustion chamber liner materials are presented. Mil-Spec RP-1, n- dodecane, propane, and methane fuels were tested in contact with OFHC, NASA-Z, and ZrCu coppers. Two distinct test methods were employed. Static tests, in which copper coupons were exposed to fuel for long durations at constant temperature and pressure, provided compatibility data in a precisely controlled environment. Dynamic tests, using the Aerojet Carbothermal Test Facility, provided fuel and copper compatibility data under realistic booster engine service conditions. Tests were conducted using very pure grades of each fuel and fuels to which a contaminant, e.g., ethylene or methyl mercaptan, was added to define the role played by fuel impurities. Conclusions are reached as to degradation mechanisms and effects, methods for the elimination of these mechanisms, selection of copper alloy combustion chamber liners, and hydrocarbon fuel purchase specifications.

  15. Design of a pyrometer for temperature measurements on the solid fuel combustion chamber

    NASA Astrophysics Data System (ADS)

    Aarts, W. J. A. M.; Wijchers, T.

    1987-10-01

    A pyrometer was developed for the measurement of the flame temperature of the solid fuel combustion chamber. The principle of the design is based on the measurement of the spectral intensity at two wavelengths, 577 and 830 nm, emitted by the soot in the flame. The ratio of the intensities is a univocal measure of the color temperature at these wavelengths. The apparatus is small, robust and user friendly. Calibration currents which imitate the output of the detectors are used to control the electronic circuits. The preliminary measuring accuracy between 1400 and 2800 K is about 20 K if the pyrometer is calibrated every 4 months using a qualified tungsten ribbon lamp.

  16. Innovative Approaches to Fuel-Air Mixing and Combustion in Airbreathing Hypersonic Engines

    NASA Astrophysics Data System (ADS)

    MacLeod, C.

    This paper describes some innovative methods for achieving enhanced fuel-air mixing and combustion in Scramjet-like spaceplane engines. A multimodal approach to the problem is discussed; this involves using several concurrent methods of forced mixing. The paper concentrates on Electromagnetic Activation (EMA) and Electrostatic Attraction as suitable techniques for this purpose - although several other potential methods are also discussed. Previously published empirical data is used to draw conclusions about the likely effectiveness of the system and possible engine topologies are outlined.

  17. Fuels-combustion resaearch. Annual technical report, 1 October 1985-30 September 1986

    SciTech Connect

    Dryer, F.L.; Glassman, I.; Williams, F.A.

    1986-10-31

    After great progress related to soot formation in normal diffusion flames, studies of near sooting inverse-diffusion flames were begun to determine controlling precursors. Stable, temperature-controlled inverse-diffusion flames were successfully developed and numerous chemical samples extracted and analyzed. Observed trends are being studied. The side-chain oxidation of n-butyl benzene was found to follow the same processes as the smaller n-alkyl benzenes; abstraction, alkyl group displacement and thermal cleavage. The results led to development of a simple general, mechanistic model for the oxidation of n-alkyl benzenes. Combustion-property observations of isolated boron droplets were extended to boron/JP-10 slurries with various solid loadings. Some physical understanding of observed droplet burning and disruption behavior was developed. Quasi-spherical hollow shells of the boron agglomerate with blowholes support the hypothesis of the formation of the impermeable shell and subsequent disruption of the primary slurry droplet. Boron suspension (cloud) combustion in the hot reaction products of a flat-flame burner has been pursued. The boric acid fluctuation bands were identified spectroscopically, and conditions for their flame occurrence measured. The work progresses toward establishment of ignition conditions and combustion times of 0.1-5 micron boron particles.

  18. Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion

    NASA Technical Reports Server (NTRS)

    Bittker, D. A.; Wolfbrandt, G.

    1981-01-01

    How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.

  19. Study of the performance, emission and combustion characteristics of a diesel engine using poon oil-based fuels

    Microsoft Academic Search

    P. K. Devan; N. V. Mahalakshmi

    2009-01-01

    Experiments were conducted to study the performance, emission and combustion characteristics of a DI diesel engine using poon oil-based fuels. In the present work, poon oil and poon oil methyl ester are tested as diesel fuels in Neat and blended forms. The blends were prepared with 20% poon oil and 40% poon oil methyl ester separately with standard diesel on

  20. Life cycle comparison of fuel cell vehicles and internal combustion engine vehicles for Canada and the United States

    Microsoft Academic Search

    Nada Zamel; Xianguo Li

    2006-01-01

    The objective of this study is to put forward a full analysis of the impact of the difference between the Canadian and American energy realities on the life cycle of fuel cell vehicles and internal combustion engine vehicles. Electricity is a major type of energy used in the transportation sector. Electricity is needed in the production of feedstock of fuel,

  1. Investigation of slagging in pulverized fuel co-combustion of biomass and coal at a pilot-scale test facility

    Microsoft Academic Search

    T. Heinzel; V. Siegle; H. Spliethoff; K. R. G. Hein

    1998-01-01

    One option to reduce the CO2 emissions is biomass used for energy production. Co-combustion of biomass in existing coal-fired power stations offers a great potential. In pulverized coal combustion facilities, one implementation problem is the tendency of slagging and fouling of biomass. At the IVD, experiments were carried out to obtain information about biomass deposit characteristics in pulverized fuel (pf)

  2. Effects of multiple-injection strategies on overall spray behavior, combustion, and emissions reduction characteristics of biodiesel fuel

    Microsoft Academic Search

    Su Han Park; Seung Hyun Yoon; Chang Sik Lee

    2011-01-01

    This study described the combustion and exhaust emissions characteristics of biodiesel fuel with multiple-injection strategies. Also, this investigation included the free spray characteristics and in-cylinder spray behaviors of the multiple-injection modes. Free spray and in-cylinder spray images were obtained from the spray visualization system. Combustion and exhaust emissions characteristics were analyzed using a single cylinder diesel engine with a displacement

  3. Comparison of chars obtained under oxy-fuel and conventional pulverized coal combustion atmospheres

    SciTech Connect

    Angeles G. Borrego; Diego Alvarez [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2007-12-15

    In this study, two coals of different rank (a high volatile and a low volatile bituminous) have been burned in a drop tube reactor using O{sub 2}/N{sub 2} and O{sub 2}/CO{sub 2} mixtures with increasing oxygen content from 0 to 21%. Various oxygen concentrations have been selected for each set of experiments in order to follow both the progress of combustion and the influence of oxygen content in the devolatilization behavior of coal. Results show that a higher amount of O{sub 2} in CO{sub 2} than in N{sub 2} is needed to achieve similar burnout levels. Significant differences were found in the influence of oxygen content on the devolatilization behavior of the lower and higher rank coal. The limited amount of oxygen in the reacting atmosphere resulted in volatile release inhibition for the high volatile bituminous coal, whereas the more plastic low volatile coal was hardly affected. The presence of variable amounts of oxygen in CO{sub 2} had a small influence on the char particle appearance. The chars from both the combustion series (O{sub 2}/N{sub 2}) and the oxy-fuel series (O{sub 2}/CO{sub 2}) were similar for each parent coal in terms of reactivity and micropore surface area measured by CO{sub 2} adsorption. The main difference between both series of chars relied on the surface area determined by N{sub 2} adsorption (SBET) and on the size distribution of pores which was shifted to a larger size for the oxy-fuel series. The difference between both series of chars was larger for the high volatile bituminous coal chars than for the low volatile bituminous coal chars. This might have important implications for combustion under the diffusion-controlled regime. 29 refs., 13 figs., 1 tab.

  4. Fuel property effects in stirred combustors

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Soot formation in strongly backmixed combustion was investigated using the jet-stirred combustor (JSC). This device provided a combustion volume in which temperature and combustion were uniform. It simulated the recirculating characteristics of the gas turbine primary zone; it was in this zone where mixture conditions were sufficiently rich to produce soot. Results indicate that the JSC allows study of soot formation in an aerodynamic situation revelant to gas turbines.

  5. Fuel correlations for combustion purposes, a summary of progress within the past fifteen years. Part 1

    SciTech Connect

    Kretschmer, D.; Odgers, J. [Laval Univ., Quebec City, Quebec (Canada). Dept. of Mechanical Engineering

    1996-12-31

    Over the years, many correlations for fuel properties have been developed at Laval University. The main goal in this was to provide tools to estimate unknown fuel properties form the known values of the density and the viscosity at one temperature and the ASTM D-86 distillation, since these data are easily determined. For liquid fuels the target was set to establish as many fuel properties as possible which could be derived from three measurements (1) the density at 298 K, (2) the ASTM distillation, (3) the fuel viscosity at a single temperature. These correlations have been published piecemeal in the literature or in report form, but not as an ensemble. The objective of the present work is to list the available correlations and indicate their accuracy and applications.

  6. Theoretical studies of oxides relevant to the combustion of fossil fuels

    NASA Astrophysics Data System (ADS)

    Hicks, Jason Michael

    Anthropogenic pollution has greatly increased since the industrial revolution and continues to increase as more of the world becomes dependent upon fossil fuels for important applications like transportation and power production. In a general case, whenever a fossil fuel is consumed, a primary product of a complete combustion reaction is carbon dioxide. In a more specific case, the collection, processing and combustion of coal for power production are one of the primary ways by which trace elements, such as arsenic and selenium, are released into the environment. All of these pollutants are known to have harmful effects, whether on the environment, human health or power production itself. Because of this there has been an increasing interest in studies related to combating these pollutants. Concerning CO2 emissions, recently there has been a significant amount of work related to CO2 capture. A promising method involves the encapsulation of CO2 into isoreticular metal-organic frameworks (IRMOFs). The effectiveness of IMROFs greatly depends on the choice of both metal and organic parts. Molecular simulations have been used in the past to aid in the design and characterization of new MOFs, in particular by generating an adsorption isotherm. However, these traditional simulation methods have several drawbacks. The method used in this thesis, namely expanded Wang-Landau, not only overcomes these drawbacks but provides access to all the thermodynamic properties relevant to the adsorption process through a solution thermodynamics approach. This is greatly beneficial, since an excellent way to characterize the performance of various MOFs is by comparing their desorption free energy, i.e., the energy it takes to regenerate a saturated MOF to prepare it for the next adsorption cycle. Expanded WL was used in the study of CO 2 adsorption into IRMOF-1, 8 and 10 at eight temperatures, spanning both the subcritical and supercritical regimes and the following were obtained: adsorption isotherms, Gibbs free energy, enthalpy, entropy and desorption free energy. It was found that, when the maximum loading was compared to the regeneration costs, IRMOF-10 had the best performance, followed by IRMOF-8 then IRMOF-1. During the combustion of coal, not only is CO2 produced, but also the trace elements of arsenic and selenium escape into the environment though this process. Both arsenic and selenium are known to have a harmful effects on the environment and human health. Arsenic is also known to poison the catalytic converter used in selective catalytic reduction of NOx . These trace elements have been found on fly ash or in the hot flue gases released into the atmosphere. In flue gases they most often exist as oxides. There have been many experimental and a few theoretical studies on the monomeric oxides, AsOx and SeOx, where x = 1, 2, or 3. However, little is known concerning the corresponding dimeric oxides, As2Ox and Se2Ox, where x = 3 or 5, though these compounds are expected from their similarities to nitrogen and sulfur chemistry, respectively. From an experimental perspective, they are very challenging to study due to the high temperatures, complex environments and low concentrations needed for a direct study of the form and structures of the dimeric oxides. From a theoretical perspective, they can be challenging to study due to their multireference character and the need for both dynamic and non-dynamic electron correlation due to bonds forming and breaking during isomerization. However, high level multireference ab initio methods which account for both dynamic and non-dynamic electron correlation can be used. In the work contained in this thesis, GVVPT2 and CR-CC(2,3) were used to study the relative stabilities of all relevant isomers and transition states of As2Ox and Se2Ox. The structures used where generated through DFT using the B3LYP functional. Not only were plausible stationary points located for all species, it was further confirmed that GVVPT2, though with lower computational cost than CR-CC(2,3), can accurately predict such co

  7. Ignition and combustion of liquid fuel droplet in a convective medium

    SciTech Connect

    Dash, S.K.; Som, S.K. (Dept. of Mechanical Engineering, Indian Inst. of Technology, Kharagpur (IN))

    1991-09-01

    This paper reports that an mathematical model of droplet combustion in surroundings of hot gas with a uniform free stream motion is made from the numerical solution of the conservation equations of heat, mass and momentum in both the carrier and droplet phases. The gas phase chemical reaction between fuel vapor and oxidizer is assumed to be a single-step irreversible one. The phenomena of ignition is recognized by the sudden rise of temperature in the temperature-time histories at different locations in the carrier phase. The relative influences of pertinent input parameters, namely initial Reynolds number Re{sub i}, ratio of free stream to initial drop temperature T{sub infinity}, and the ambient pressure on: the ignition time lad, extinction characteristics, and life histories of burning fuel drops have been established.

  8. Compression and combustion of non-cryogenic targets with a solid thermonuclear fuel for inertial fusion

    SciTech Connect

    Gus'kov, S. Yu., E-mail: guskov@sci.lebedev.ru [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Zmitrenko, N. V. [Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation); Sherman, V. E. [St. Petersburg State Polytechnic University (Russian Federation)

    2013-04-15

    Variants of a target with a solid thermonuclear fuel in the form of deuterium-tritium hydrides of light metals for an inertial fusion have been proposed. The laser-pulse-induced compression of non-cryogenic targets, as well as ignition and combustion of such targets, has been examined. The numerical calculations show that, despite a decrease in the caloric content of the fuel and an increase in the energy losses on intrinsic radiation in the target containing deuterium-tritium hydrides of light metals as compared to the target containing deuterium-tritium ice, the non-cryogenic target can ensure the fusion gain sufficient for its use in the energy cycle of a thermonuclear power plant based on the inertial plasma confinement method.

  9. Premixed mixture ignition in the end-gas region (PREMIER) combustion in a natural gas dual-fuel engine: operating range and exhaust emissions

    Microsoft Academic Search

    U Azimov; E Tomita; N Kawahara; Y Harada

    2011-01-01

    This paper is concerned with engine experiments and spectroscopic analysis of premixed mixture ignition in the end-gas region (PREMIER) combustion in a pilot fuel ignited, natural gas dual-fuel engine. The results reveal the characteristics and operating parameters that induce and affect this combustion mode. The PREMIER combustion is followed by natural gas flame propagation. Pilot-injected diesel fuel ignites the natural

  10. Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion

    SciTech Connect

    Choudhuri, Ahsan

    2013-05-30

    Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO{sub 2} from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H{sub 2} concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO{sub 2} and H{sub 2}O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient g{sub F}) values for CH{sub 4}-O{sub 2}-CO{sub 2} flames. The scaling relation (𝐠{sub F} = 𝐜 𝐒{sub 𝐋}{sup 2}/𝛂) for different burner diameters was obtained for various diameter burners. The report shows that results correlated linearly with a scaling value of c =0.0174. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH{sub 4}/21%O{sub 2}/79%N{sub 2} and CH{sub 4}/38%O{sub 2}/72%CO{sub 2} mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of CH{sub 4}/air and CH{sub 4}/38%O{sub 2}/72%CO{sub 2} combustion. The velocity fluctuations, turbulence intensities and local propagation velocities along the combustion chamber have been determined. The turbulent intensities increase as we move away from the combustor axis. CH{sub 4}-38%O{sub 2}-72%CO{sub 2} flames have low radial velocity and turbulent intensity distributions at different axial distances when compared with CH{sub 4}-Air flames.

  11. Particulate Emissions from the Combustion of Diesel Fuel with a Fuel-Borne Nanoparticulate Cerium Catalyst

    NASA Astrophysics Data System (ADS)

    Conny, J. M.; Willis, R. D.; Weinstein, J. P.; Krantz, T.; King, C.

    2013-12-01

    To address the adverse impacts on health and climate from the use of diesel-fueled vehicles, a number of technological solutions have been developed for reducing diesel soot emissions and to improve fuel economy. One such solution is the use fuel-borne metal oxide catalysts. Of current interest are commercially-available fuel additives consisting of nanoparticulate cerium oxide (CeO2). In response to the possible use of CeO2-containing fuels in on-road vehicles in the U.S., the Environmental Protection Agency is conducting research to address the potential toxicity and environmental effects of particulate CeO2 emitted with diesel soot. In this study, emissions from a diesel-fueled electric generator were size-segregated on polished silicon wafers in a nanoparticle cascade impactor. The diesel fuel contained 10 ppm Ce by weight in the form of crystalline CeO2 nanoparticles 4 nm to 7.5 nm in size. Primary CeO2 nanoparticles were observed in the diesel emissions as well as CeO2 aggregates encompassing a broad range of sizes up to at least 200 nm. We report the characterization of individual particles from the size-resolved samples with focused ion-beam scanning electron microscopy and energy-dispersive x-ray spectroscopy. Results show a dependency between the impactor size range and CeO2 agglomeration state: in the larger size fractions of the impactor (e.g., 560 nm to 1000 nm) CeO2 nanoparticles were predominantly attached to soot particles. In the smaller size fractions of the impactor (e.g., 100 nm to 320 nm), CeO2 aggregates tended to be larger and unattached to soot. The result is important because the deposition of CeO2 nanoparticles attached to soot particles in the lung or on environmental surfaces such as plant tissue will likely present different consequences than the deposition of unagglomerated CeO2 particles. Disclaimer The U.S. Environmental Protection Agency through its Office of Research and Development funded and collaborated in the research described here under Interagency Agreement DW-13-92339401 to National Institute of Standards and Technology. It has been subjected to Agency review and approved for publication.

  12. Numerical studies of integral equation and rod models of solid fuel combustion

    NASA Astrophysics Data System (ADS)

    Park, Jang Hoon

    We consider modes of solid flame propagation associated with the SHS (Self Propagating High Temperature Synthesis) process of materials synthesis. In this process reactants are ground into a powder, cold pressed into a solid sample, typically a cylinder, and ignited at one end. Synthesis ensues as a high temperature self-sustaining combustion wave propagates through the sample converting reactants to products. When gas plays no significant role in the process the resulting gasless combustion wave is referred to as a "solid flame". First we consider nonadiabatic gasless solid fuel combustion employing a reaction sheet model. We derive an integrodifferential equation for the location of the interface separating the fresh fuel from the burned products. For all values of the scaled activation energy, Z, and heat loss parameter, Gamma, the model admits a uniformly propagating combustion wave. This solution is subject to a pulsating instability for Z sufficiently large. We find that for Z slightly below the adiabatic stability limit, the effect of heat loss is to promote a period doubling cascade leading to chaotic behavior prior to extinction. We also find an interval of laminar behavior within the chaotic window, corresponding to a secondary period doubling sequence. We next consider an array of interacting rods, each of which supports propagating waves. Thus, we employ an array of interacting 1D rods connected via heat transfer. The heat transfer terms correspond to a discretization of the transverse Laplacian. We consider first a rod model consisting of an outer ring of 3 rods equally spaced along the ring, together with an axial rod. We find a multitude of solutions including spinning, radial, and quasiperiodic solutions. We next consider an 8/8/1 rod model in which 8 equally spaced rods are located at the surface of the cylinder, another 8 equally spaced rods are on a concentric circle located halfway inside the cylinder, and an axial rod is located on the axis. Neighboring rods are connected to one another via heat transfer. We find numerous spin, radial, periodic, and quasiperiodic solutions and compare these solutions with possible 3D analogues.

  13. Simulating Combustion

    Microsoft Academic Search

    G. Merker; C. Schwarz; G. Stiesch; F. Otto

    2006-01-01

    The content spans from simple thermodynamics of the combustion engine to complex models for the description of the air\\/fuel mixture, ignition, combustion and pollutant formation considering the engine periphery of petrol and diesel engines. Thus the emphasis of the book is on the simulation models and how they are applicable for the development of modern combustion engines. Computers can be

  14. Proceedings of the Biomass Pyrolysis Oil Properties and Combustion Meeting, 26-28 September 1994, Estes Park, Colorado

    SciTech Connect

    Milne, T.

    1995-01-01

    The increasing scale-up of fast pyrolysis in North America and Europe, as well as the exploration and expansion of markets for the energy use of biocrude oils that now needs to take place, suggested that it was timely to convene an international meeting on the properties and combustion behavior of these oils. A common understanding of the state-of-the-art and technical and other challenges which need to be met during the commercialization of biocrude fuel use, can be achieved. The technical issues and understanding of combustion of these oils are rapidly being advanced through R&D in the United States. Canada, Europe and Scandinavia. It is obvious that for the maximum economic impact of biocrude, it will be necessary to have a common set of specifications so that oils can be used interchangeably with engines and combustors which require minimal modification to use these renewable fuels. Fundamental and applied studies being pursued in several countries are brought together in this workshop so that we can arrive at common strategies. In this way, both the science and the commercialization are advanced to the benefit of all, without detracting from the competitive development of both the technology and its applications. This United States-Canada-Finland collaboration has led to the two and one half day specialists meeting at which the technical basis for advances in biocrude development is discussed. The goal is to arrive at a common agenda on issues that cross national boundaries in this area. Examples of agenda items are combustion phenomena, the behavior of trace components of the oil (N, alkali metals), the formation of NOx in combustion, the need for common standards and environmental safety and health issues in the handling, storage and transportation of biocrudes.

  15. Effect of different fuels on the alumina–ceria composite powders synthesized by sol–gel auto combustion method

    Microsoft Academic Search

    J. Chandradass; M. Balasubramanian; Dong-sik Bae; Ki Hyeon Kim

    2009-01-01

    In this research, a sol–gel auto combustion route has been proposed to synthesize alumina–ceria composite powder, using aluminium nitrate, cerium(III) nitrate hexahydrate and various fuels such as citric acid, acetyl acetone and oxalic acid. DTA shows the phase transformation of ?-Al2O3 and CeO2 varies with fuel. XRD confirms the formation of ?-Al2O3 and CeO2 phase irrespective of fuels at 1200°C.

  16. Transient air-fuel ratio H? preview control of a drive-by-wire internal combustion engine

    Microsoft Academic Search

    Larry Mianzot; Huei Pengt; I. Haskara

    2001-01-01

    An approach for H? Preview control of the transient air-fuel ratio control of a drive-by-wire internal combustion engine system is proposed. The fuel delivery system has significant transport and measurement delays. A preview fuel control algorithm, which uses the current measurement or estimate of air charge as well as the corresponding predicted future air charge, provides compensation for these delays.

  17. Presence of estrogenic activity from emission of fossil fuel combustion as detected by a recombinant yeast bioassay

    NASA Astrophysics Data System (ADS)

    Wang, Jingxian; Wu, Wenzhong; Henkelmann, Bernhard; You, Li; Kettrup, Antonius; Schramm, Karl-Werner

    Estrogenic activities of emission samples generated by fossil fuel combustion were investigated with human estrogen receptor (ER) recombinant yeast bioassay. The results showed that there were weak but clear estrogenic activities in combustion emissions of fossil fuels including coal, petroleum, and diesel. The estrogenic relative potency (RP) of fossil fuel combustion was the highest in petroleum-fired car, followed by coal-fired stove, diesel-fired agrimotor, coal-fired electric power station. On the other hand, the estrogenic relative inductive efficiency (RIE) was the highest in coal-fired stove and coal-fired electric power station, followed by petroleum-fired car and diesel-fired agrimotor. The estrogenic activities in the sub-fractions from chromatographic separation of emitted materials were also determined. The results indicated that different chemical fractions in these complex systems have different estrogenic potencies. The GC/MS analysis of the emission showed that there were many aromatic carbonyls, big molecular alcohol, PAHs and derivatives, and substituted phenolic compounds and derivatives which have been reported as environmental estrogens. The existence of estrogenic substances in fossil fuel combustion demands further investigation of their potential adverse effects on human and on the ecosystem. The magnitude of pollution due to global usage of fossil fuels makes it imperative to understand the issue of fossil fuel-derived endocrine activities and the associated health risks, particularly the aggregated risks stemmed from exposure to toxicants of multiple sources.

  18. Combustion chamber for internal combustion engines

    Microsoft Academic Search

    Kawamura

    1988-01-01

    A combustion chamber for internal combustion engines, of the type including means for producing swirl within the combustion chamber is described comprising: a combustion chamber provided in the head portion of a piston in the form of a cavity recessed in the axial direction of the piston; fuel injection nozzle means disposed in the combustion chamber and positioned eccentrically with

  19. Numerical Simulation of the Combustion of Fuel Droplets: Finite Rate Kinetics and Flame Zone Grid Adaptation (CEFD)

    NASA Technical Reports Server (NTRS)

    Gogos, George; Bowen, Brent D.; Nickerson, Jocelyn S.

    2002-01-01

    The NASA Nebraska Space Grant (NSGC) & EPSCoR programs have continued their effort to support outstanding research endeavors by funding the Numerical Simulation of the Combustion of Fuel Droplets study at the University of Nebraska at Lincoln (UNL). This team of researchers has developed a transient numerical model to study the combustion of suspended and moving droplets. The engines that propel missiles, jets, and many other devices are dependent upon combustion. Therefore, data concerning the combustion of fuel droplets is of immediate relevance to aviation and aeronautical personnel, especially those involved in flight operations. The experiments being conducted by Dr. Gogos and Dr. Nayagam s research teams, allow investigators to gather data for comparison with theoretical predictions of burning rates, flame structures, and extinction conditions. The consequent improved hndamental understanding droplet combustion may contribute to the clean and safe utilization of fossil hels (Williams, Dryer, Haggard & Nayagam, 1997, 72). The present state of knowledge on convective extinction of he1 droplets derives fiom experiments conducted under normal gravity conditions. However, any data obtained with suspended droplets under normal gravity are grossly affected by gravity. The need to obtain experimental data under microgravity conditions is therefore well justified and addresses one of the goals of NASA s Human Exploration and Development of Space (HEDS) microgravity combustion experiment.

  20. Effects of Fuel Composition on Combustion Stability and NO X Emissions for Traditional and Alternative Jet Fuels

    NASA Astrophysics Data System (ADS)

    Vijlee, Shazib Z.

    Synthetic jet fuels are studied to help understand their viability as alternatives to traditionally derived jet fuel. Two combustion parameters -- flame stability and NOX emissions -- are used to compare these fuels through experiments and models. At its core, this is a fuels study comparing how chemical makeup and behavior relate. Six 'real', complex fuels are studied in this work -- four are synthetic from alternative sources and two are traditional from petroleum sources. Two of the synthetic fuels are derived from natural gas and coal via the Fischer Tropsch catalytic process. The other two are derived from Camelina oil and tallow via hydroprocessing. The traditional military jet fuel, JP8, is used as a baseline as it is derived from petroleum. The sixth fuel is derived from petroleum and is used to study the effects of aromatic content on the synthetic fuels. The synthetic fuels lack aromatic compounds, which are an important class of hydrocarbons necessary for fuel handling systems to function properly. Several single-component fuels are studied (through models and/or experiments) to facilitate interpretation and understanding. The flame stability study first compares all the 'real', complex fuels for blowout. A toroidal stirred reactor is used to try and isolate temperature and chemical effects. The modeling study of blowout in the toroidal reactor is the key to understanding any fuel-based differences in blowout behavior. A detailed, reacting CFD model of methane is used to understand how the reactor stabilizes the flame and how that changes as the reactor approaches blowout. A 22 species reduced form of GRI 3.0 is used to model methane chemistry. The knowledge of the radical species role is utilized to investigate the differences between a highly aliphatic fuel (surrogated by iso-octane) and a highly aromatic fuel (surrogated by toluene). A perfectly stirred reactor model is used to study the chemical kinetic pathways for these fuels near blowout. The differences in flame stabilization can be attributed to the rate at which these fuels are attacked and destroyed by radical species. The slow disintegration of the aromatic rings reduces the radical pool available for chain-initiating and chain-branching, which ultimately leads to an earlier blowout. The NOX study compares JP8, the aromatic additive, the synthetic fuels with and without an aromatic additive, and an aromatic surrogate (1,3,5-trimethylbenzene). A jet stirred reactor is used to try and isolate temperature and chemical effects. The reactor has a volume of 15.8 mL and a residence time of approximately 2.5 ms. The fuel flow rate (hence equivalence ratio) is adjusted to achieve nominally consistent temperatures of 1800, 1850, and 1900K. Small oscillations in fuel flow rate cause the data to appear in bands, which facilitated Arrhenius-type NOX-temperature correlations for direct comparison between fuels. The fuel comparisons are somewhat inconsistent, especially when the aromatic fuel is blended into the synthetic fuels. In general, the aromatic surrogate (1,3,5-trimethylbenzene) produces the most NOX, followed by JP8. The synthetic fuels (without aromatic additive) are always in the same ranking order for NOX production (HP Camelina > FT Coal > FT Natural Gas > HP Tallow). The aromatic additive ranks differently based on the temperature, which appears to indicate that some of the differences in NOX formation are due to the Zeldovich NOX formation pathway. The aromatic additive increases NOX for the HP Tallow and decreases NOX for the FT Coal. The aromatic additive causes increased NOX at low temperatures but decreases NOX at high temperatures for the HP Camelina and FT Natural Gas. A single perfectly stirred reactor model is used with several chemical kinetic mechanisms to study the effects of fuel (and fuel class) on NO X formation. The 27 unique NOX formation reactions from GRI 3.0 are added to published mechanisms for jet fuel surrogates. The investigation first looked at iso-octane and toluene and found that toluene produces more NOX beca

  1. Effect of degree of fuel vaporization upon emissions for a premixed partially vaporized combustion system. [for gas turbine engines

    NASA Technical Reports Server (NTRS)

    Cooper, L. P.

    1980-01-01

    An experimental and analytical study of the combustion of partially vaporized fuel-air mixtures was performed to assess the impact of the degree of fuel vaporization upon emissions for a premixing-prevaporizing flametube combustor. Data collected in this study showed near linear increases in nitric oxide emissions with decreasing vaporization at equivalence ratios of 0.6. For equivalence ratios of 0.72, the degree of vaporization had very little impact on nitric oxide emissions. A simple mechanism which accounts for the combustion of liquid droplets in partially vaporized mixtures was found to agree with the measured results with fair accuracy with respect to both trends and magnitudes.

  2. Prediction of Co-Firing Characteristics of Wastes in Circulating Fluidized Bed by Fuel Properties

    NASA Astrophysics Data System (ADS)

    Murakami, Takahiro; Suda, Toshiyuki

    The purpose of this study is to experimentally investigate the co-firing characteristics of different kinds of wastes in circulating fluidized bed combustors, and further to correlate the acquired combustion efficiency with fuel property parameters. The tested individual fuels were wasted tire, RPF, wood tip, RDF and coal, which typified the fuels with distinctively different contents of volatile matters. Coal was employed to represent the fuel containing particularly low volatile matters. The experiments were carried out in a pilot circulating fluidized bed combustor, and varied parameters included the fuel blending ratio, furnace temperature and secondary air ratio. The acquired results indicated that co-firing wasted tire and RPF led to higher CO concentration in the flue gas than firing RPF independently, and this CO concentration increased with increasing the blending ratio of wasted tire. The lower volatile matter content, higher carbon to hydrogen ratio (C?H ratio) and carbon to oxygen ratio (C?O ratio) of wasted tire than those of RPF were suggested to be responsible for the results. The study also found that the available combustion efficiencies in co-firing various pairs of the tested fuels were correlative with the volatile matter contents, C?H and C?O ratios of the blended fuels estimated as the weighed sums of the same property parameters of individual fuels. This allows thus a simple determination of the co-firing efficiency of any fuel blend from calculating the blend?s fuel property parameters using the fuel blending ratio as a weight.

  3. Solubility of a diesel–biodiesel–ethanol blend, its fuel properties, and its emission characteristics from diesel engine

    Microsoft Academic Search

    Prommes Kwanchareon; Apanee Luengnaruemitchai; Samai Jai-In

    2007-01-01

    In this work, we studied the phase diagram of diesel–biodiesel–ethanol blends at different purities of ethanol and different temperatures. Fuel properties (such as density, heat of combustion, cetane number, flash point and pour point) of the selected blends and their emissions performance in a diesel engine were examined and compared to those of base diesel. It was found that the

  4. Separation of particulate from flue gas of fossil fuel combustion and gasification

    DOEpatents

    Yang, W.C.; Newby, R.A.; Lippert, T.E.

    1997-08-05

    The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The fly ash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured fly ash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled. 11 figs.

  5. Separation of particulate from flue gas of fossil fuel combustion and gasification

    DOEpatents

    Yang, Wen-Ching (Murrysville, PA); Newby, Richard A. (Pittsburgh, PA); Lippert, Thomas E. (Murrysville, PA)

    1997-01-01

    The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The flyash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured flyash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled.

  6. High-fidelity simulations for clean and efficient combustion of alternative fuels

    NASA Astrophysics Data System (ADS)

    Oefelein, J. C.; Chen, J. H.; Sankaran, R.

    2009-07-01

    There is an urgent and growing demand for high-fidelity simulations that capture complex turbulence-chemistry interactions in propulsion and power systems, and in particular, that capture and discriminate the effects of fuel variability. This project addresses this demand using the Large Eddy Simulation (LES) technique (led by Oefelein) and the Direct Numerical Simulation (DNS) technique (led by Chen). In particular, we are conducting research under the INCITE program that is tightly coupled with funded projects established under the DOE Basic Energy Sciences and Energy Efficiency and Renewable Energy programs that will provide the foundational science required to develop a predictive modeling capability for design of advanced engines for transportation. Application of LES provides the formal ability to treat the full range of multidimensional time and length scales that exist in turbulent reacting flows in a computationally feasible manner and thus provides a way to simulate reacting flow phenomena in complex internal-combustion engine geometries at device relevant conditions. Application of DNS provides a way to study fundamental issues related to small-scale combustion processes in canonical configurations to understand dynamics that occur over a range of reactive-diffusive scales. Here we describe the challenges and present representative examples of the types of simulations each respective tool has been used for as part of the INCITE program. We focus on recent experiences on the Oak Ridge National Laboratory (ORNL) National Center for Computational Sciences (NCCS) Cray-XT Platform (i.e., Jaguar).

  7. Study of electrostatic modulation of fuel sprays to enhance combustion performance in an aviation gas turbine. Master's thesis

    SciTech Connect

    Manning, W.W.

    1987-06-01

    The influence of electrostatic and electrohydrodynamic charging on hydrocarbon fuel-spray patterns and droplet atomization was investigated. Research was performed in a combustion environment with an Allison T-56 combustor liner and an unmodified pressure-jet atomizer fuel nozzle. High-voltage probes and a variable-geometry probe-insertion device were developed to assess the effectiveness of probe type and location on fuel-spray modification and modulation. Exhaust-gas temperatures and temperature profiles were measured to determine changes in the combustor's thermal profile and combustion efficiency. JP-4, JET-A and Number-2 Diesel fuels were tested to analyze electrically-assisted atomization effectiveness relative to off-design fuel performance.

  8. High resolution fossil fuel combustion CO{sub 2} emission fluxes for the United States

    SciTech Connect

    Kevin R. Gurney; Daniel L. Mendoza; Yuyu Zhou; Marc L. Fischer; Chris C. Miller; Sarath Geethakumar; Stephane de la Rue du Can [Purdue University, West Lafayette, IN (United States). Department of Earth and Atmospheric Sciences/Department of Agronomy

    2009-07-15

    Quantification of fossil fuel CO{sub 2} emissions at fine space and time resolution is emerging as a critical need in carbon cycle and climate change research. As atmospheric CO{sub 2} measurements expand with the advent of a dedicated remote sensing platform and denser in situ measurements, the ability to close the carbon budget at spatial scales of about 100 km{sup 2} and daily time scales requires fossil fuel CO{sub 2} inventories at commensurate resolution. Additionally, the growing interest in U.S. climate change policy measures are best served by emissions that are tied to the driving processes in space and time. Here we introduce a high resolution data product (the 'Vulcan' inventory: www.purdue.edu/eas/carbon/vulcan/) that has quantified fossil fuel CO{sub 2} emissions for the contiguous U.S. at spatial scales less than 100 km{sup 2} and temporal scales as small as hours. This data product, completed for the year 2002, includes detail on combustion technology and 48 fuel types through all sectors of the U.S. economy. The Vulcan inventory is built from the decades of local/regional air pollution monitoring and complements these data with census, traffic, and digital road data sets. The Vulcan inventory shows excellent agreement with national-level Department of Energy inventories, despite the different approach taken by the DOE to quantify U.S. fossil fuel CO{sub 2} emissions. Comparison to the global 1{sup o} x 1{sup o} fossil fuel CO{sub 2} inventory, used widely by the carbon cycle and climate change community prior to the construction of the Vulcan inventory, highlights the space/time biases inherent in the population-based approach. 39 refs., 5 figs., 1 tab.

  9. Hybrid rocket combustion study

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Ray, R. L.; Cohen, N. S.

    1993-01-01

    The objectives of this study of 'pure' or 'classic' hybrids are to (1) extend our understanding of the boundary layer combustion process and the critical engineering parameters that define this process, (2) develop an up-to-date hybrid fuel combustion model, and (3) apply the model to correlate the regression rate and scaling properties of potential fuel candidates. Tests were carried out with a hybrid slab window motor, using several diagnostic techniques, over a range of motor pressure and oxidizer mass flux conditions. The results basically confirmed turbulent boundary layer heat and mass transfer as the rate limiting process for hybrid fuel decomposition and combustion. The measured fuel regression rates showed good agreement with the analytical model predictions. The results of model scaling calculations to Shuttle SRM size conditions are presented.

  10. Prediction of Combustion Stability and Flashback in Turbines with High-Hydrogen Fuel

    SciTech Connect

    Lieuwen, Tim; Santavicca, Dom; Yang, Vigor

    2012-03-31

    During the duration of this sponsorship, we broadened our understanding of combustion instabilities through both analytical and experimental work. Predictive models were developed for flame response to transverse acoustic instabilities and for quantifying how a turbulent flame responds to velocity and fuel/air ratio forcing. Analysis was performed on the key instability mechanisms controlling heat release response for flames over a wide range of instability frequencies. Importantly, work was done closely with industrial partners to transition existing models into internal instability prediction codes. Experimentally, the forced response of hydrogen-enriched natural gas/air premixed and partially premixed flames were measured. The response of a lean premixed flame was investigated, subjected to velocity, equivalence ratio, and both forcing mechanisms simultaneously. In addition, important physical mechanisms controlling the response of partially premixed flames to inlet velocity and equivalence ratio oscillations were analyzed. This final technical report summarizes our findings and major publications stemming from this program.

  11. Combustion behaviour and thermal properties of UV cured methacrylated phosphate\\/epoxy acrylate blends

    Microsoft Academic Search

    Shengwu Zhu; Wenfang Shi

    2003-01-01

    Methacrylated phosphates (MAPs) were blended in certain ratios with a commercial epoxy acrylate to obtain UV curable flame retardant resins. The flame retardancy and thermal properties of their UV cured films were investigated by the combustion behaviour, limiting oxygen index (LOI), thermal degradation and glass transition temperature (Tg). The results showed that the peak and average heat release rates decreased

  12. Effects of diesel fuel combustion-modifier additives on In-cylinder soot formation in a heavy-duty Dl diesel engine

    Microsoft Academic Search

    Mark P. Musculus; Jeff Dietz

    2005-01-01

    Based on a phenomenological model of diesel combustion and pollutant-formation processes, a number of fuel additives that could potentially reduce in-cylinder soot formation by altering combustion chemistry have been identified. These fuel additives, or ''combustion modifiers'', included ethanol and ethylene glycol dimethyl ether, polyethylene glycol dinitrate (a cetane improver), succinimide (a dispersant), as well as nitromethane and another nitro-compound mixture.

  13. Co-combustion of coal and biomass in pulverized fuel and fluidized bed systems -- Activities and research in Europe

    SciTech Connect

    Hein, K.R.G.; Spliethoff, H.

    1999-07-01

    Biomass or sewage sludge utilized as additional fuel in coal combustion systems has consequences on combustion behavior, emissions, corrosion, and residual matter. Therefore, at the beginning of 1993 the European Union within the frame of the APAS program launched a project called ``Combined Combustion of Biomass/Sewage Sludge and Coal''. Within this project, the effects of burning sewage sludge and agricultural residuals such as straw and manure as well as specially grown energy plants in combination with coals of various ranks and origin were studied for the most common large-scale systems in order to establish both the optimum and the technically achievable process modifications necessary for co-combustion. Based on the experience of the APAS program, the objective of a further EU-co-funded project titled ``Operational problems, trace emissions and by-product management for industrial biomass co-combustion'' was to concentrate the research effort on the problem areas like slagging, fouling, corrosion, ash utilization and trace emissions for different co-combustion systems and carefully investigate technical options to avoid these negative effects. The solution of these technical problems is essential for a technically and economically feasible and environmentally advantageous co-combustion and will promote a widespread utilization of existing biomass resources. The project provides a comparison of different biomass co-utilization concepts with regard to fouling, slagging, corrosion, ash utilization and trace emissions. In detail the project incorporated biofuels like wood, wood pulp, bark, straw, wood matter from pressed olive stones and sewage sludge. The major operational problems like slagging, fouling and corrosion were investigated in both PF and CFB units of various scales. Finally the effect of co-combustion on the by-product management - handling, utilization and disposal are evaluated and compared with a pure coal or pure biomass combustion system, respectively. As a further approach to avoid the above problems of co-utilization the pretreatment of biomass to remove the undesired components before combustion has been investigated by washing, pyrolysis or gasification prior to combustion. The potential of utilization the gaseous product from pyrolysis or gasification as reburn fuel for NO reduction was evaluated.

  14. NASA/General Electric broad-specification fuels combustion technology program - Phase I results and status

    NASA Technical Reports Server (NTRS)

    Dodds, W. J.; Ekstedt, E. E.; Bahr, D. W.; Fear, J. S.

    1982-01-01

    A program is being conducted to develop the technology required to utilize fuels with broadened properties in aircraft gas turbine engines. The first phase of this program consisted of the experimental evaluation of three different combustor concepts to determine their potential for meeting several specific emissions and performance goals, when operated on broadened property fuels. The three concepts were a single annular combustor; a double annular combustor; and a short single annular combustor with variable geometry. All of these concepts were sized for the General Electric CF6-80 engine. A total of 24 different configurations of these concepts were evaluated in a high pressure test facility, using four test fuels having hydrogen contents between 11.8 and 14%. Fuel effects on combustor performance, durability and emissions, and combustor design features to offset these effects were demonstrated.

  15. Stability analysis of a liquid fuel annular combustion chamber. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. H.

    1979-01-01

    The problems of combustion instability in an annular combustion chamber are investigated. A modified Galerkin method was used to produce a set of modal amplitude equations from the general nonlinear partial differential acoustic wave equation. From these modal amplitude equations, the two variable perturbation method was used to develop a set of approximate equations of a given order of magnitude. These equations were modeled to show the effects of velocity sensitive combustion instabilities by evaluating the effects of certain parameters in the given set of equations. By evaluating these effects, parameters which cause instabilities to occur in the combustion chamber can be ascertained. It is assumed that in the annular combustion chamber, the liquid propellants are injected uniformly across the injector face, the combustion processes are distributed throughout the combustion chamber, and that no time delay occurs in the combustion processes.

  16. Physico-chemical and optical properties of combustion-generated particles from coal-fired power plant, automobile and ship engine and charcoal kiln.

    NASA Astrophysics Data System (ADS)

    Kim, Hwajin

    2015-04-01

    Similarities and differences in physico-chemical and optical properties of combustion generated particles from various sources were investigated. Coal-fired power plant, charcoal kiln, automobile and ship engine were major sources, representing combustions of coal, biomass and two different types of diesel, respectively. Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDX) equipped with both SEM and HRTEM were used for physico-chemical analysis. Light absorbing properties were assessed using a spectrometer equipped with an integrating sphere. Particles generated from different combustion sources and conditions demonstrate great variability in their morphology, structure and composition. From coal-fired power plant, both fly ash and flue gas were mostly composed of heterogeneously mixed mineral ash spheres, suggesting that the complete combustion was occurred releasing carbonaceous species out at high temperature (1200-1300 °C). Both automobile and ship exhausts from diesel combustions show typical features of soot: concentric circles comprised of closely-packed graphene layers. However, heavy fuel oil (HFO) combusted particles from ship exhaust demonstrate more complex compositions containing different morphology of particles other than soot, e.g., spherical shape of char particles composed of minerals and carbon. Even for the soot aggregates, particles from HFO burning have different chemical compositions; carbon is dominated but Ca (29.8%), S (28.7%), Na(1%), and Mg(1%) are contained, respectively which were not found from particles of automobile emission. This indicates that chemical compositions and burning conditions are significant to determine the fate of particles. Finally, from biomass burning, amorphous and droplet-like carbonaceous particles with no crystallite structure are observed and they are generally formed by the condensation of low volatile species at low-temperature (~300-800 °C) combustion conditions. Depending on burning sources, significantly different optical properties were observed; diesel combustion particles from automobile and ship showed wavelength independent absorbing properties whereas the particles from coal and charcoal kiln combustion showed the enhanced absorption at shorter wavelength which is a brown carbon characteristic. Our findings suggest that source dependent properties and distributions across the globe should be considered when their impacts on climate change and air qualities are discussed.

  17. Properties of jet engine combustion particles during the PartEmis experiment: Particle size spectra (d > 15 nm) and volatility

    NASA Astrophysics Data System (ADS)

    Nyeki, S.; Gysel, M.; Weingartner, E.; Baltensperger, U.; Hitzenberger, R.; Petzold, A.; Wilson, C. W.

    2004-09-01

    Size distributions (d > 15 nm) and volatile properties of combustion particles were measured during test-rig experiments on a jet engine, consisting of a combustor and three simulated turbine stages (HES). The combustor was operated to simulate legacy (inlet temperature 300°C) and contemporary (500°C) cruise conditions, using kerosene with three different fuel sulfur contents (FSC; 50, 400 and 1300 ?g g-1). Measurements found that contemporary cruise conditions resulted in lower number emission indices (EIN15) and higher geometric mean particle diameter (dG) than for legacy conditions. Increasing FSC resulted in an overall increase in EIN15 and decrease in dG. The HES stages or fuel additive (APA101) had little influence on EIN15 or dG, however, this is uncertain due to the measurement variability. EIN15 for non-volatile particles was largely independent of all examined conditions.

  18. Fuel design and management for the control of advanced compression-ignition combustion modes

    Microsoft Academic Search

    Xingcai Lu; Dong Han; Zhen Huang

    2011-01-01

    Due to concerns regarding the greenhouse effect and limitations on carbon dioxide emissions, the possibility of a next-generation combustion mode for internal combustion engines that can simultaneously reduce exhaust emissions and substantially improve thermal efficiency has drawn increasing attention. The most prominent characteristic of new combustion modes, such as Homogenous-Charge Compression-Ignition (HCCI), Stratified-Charge Compression-Ignition (SCCI), and Low-Temperature Combustion (LTC), is

  19. Fundamental aspects of coal-water fuel droplet combustion and secondary atomization of coal-water mixtures: Final report: Volume 1

    Microsoft Academic Search

    S. W. Kang; A. F. Sarofim; J. D. Teare; J. M. Beer

    1987-01-01

    This Final Report is issued in two volumes, covering research into the combustion of coal-water fuels. Two separate but related tasks are discussed: Volume I, contains results obtained under Task 1 - ''Fundamental Aspects of Coal-Water Fuel Droplet Combustion''; Volume II describes the work of Task 2 - ''Secondary Atomization of Coal Water Mixtures,'' which included experimental measurements in a

  20. PROCEDURES FOR COMPARING COMBUSTION EMISSIONS FROM SYNTHETIC AND PETROLEUM FUELS. PHASE 1

    EPA Science Inventory

    The report gives results of combustion tests of petrofuels and synfuels at EPA's Research Triangle Park (NC) combustion laboratory on a 740-kW (thermal input) package boiler and a 190-kW (250 hp) stationary diesel internal combustion engine. These tests were the first in a series...