Science.gov

Sample records for fuel property combustion

  1. Fuel properties to enable lifted-flame combustion

    SciTech Connect

    Kurtz, Eric

    2015-03-15

    The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental understanding of flame lift-off, generate model validation data, and demonstrate LLFC concurrent with FMC efforts. Additionally, LLNL was added to the project during the second year to develop a detailed kinetic mechanism for a key oxygenate to support CFD modeling. Successful completion of this project allowed the team to enhance fundamental understanding of LLFC, improve the state of current combustion models and increase understanding of desired fuel properties. This knowledge also improves our knowledge of how cost effective and environmentally friendly renewable fuels can assist in helping meet future emission and greenhouse gas regulations.

  2. 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.

  3. Aviation-fuel property effects on combustion

    NASA Technical Reports Server (NTRS)

    Rosfjord, T. J.

    1984-01-01

    The fuel chemical property influence on a gas turbine combustor was studied using 25 test fuels. Fuel physical properties were de-emphasized by using fuel injectors which produce highly-atomized, and hence rapidly vaporizing sprays. A substantial fuel spray characterization effort was conducted to allow selection of nozzles which assured that such sprays were achieved for all fuels. The fuels were specified to cover the following wide ranges of chemical properties: hydrogen, 9.1 to 15 (wt) pct; total aromatics, 0 to 100 (vol) pct; and naphthalene, 0 to 30 (vol) pct. standard fuels (e.g., Jet A, JP4), speciality products (e.g., decalin, xylene tower bottoms) and special fuel blends were included. The latter group included six, 4-component blends prepared to achieve parametric variations in fuel hydrogen, total aromatics and naphthalene contents. The principle influences of fuel chemical properties on the combustor behavior were reflected by the radiation, liner temperature, and exhaust smoke number (or equivalently, soot number density) data. Test results indicated that naphthalene content strongly influenced the radiative heat load while parametric variations in total aromatics did not.

  4. 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.

  5. 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.

  6. Combustion gas properties. Part 3: Hydrogen gas fuel and dry air

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    A series of computations has been made to produce the equilibrium temperature and gas composition for hydrogen 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 sample tables and figures are provided in this report.

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

    SciTech Connect

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

    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 analyses and thermodynamic characterizations. Details of the actual results of the fuel formulations compared with the design values are presented, as well as results from standard analyses, such as heating value, viscosity and density. Cetane number characterizations were accomplished by using both the engine method and the Ignition Quality Tester (IQT/sT) apparatus.

  8. An Analysis of the Impact of Selected Fuel Thermochemical Properties on Internal Combustion Engine Efficiency

    SciTech Connect

    Szybist, James P; Chakravathy, Kalyana; Daw, C Stuart

    2012-01-01

    In this study we model the effects of 23 different fuels on First and Second Law thermodynamic efficiency of an adiabatic internal combustion engine. First Law efficiency is calculated using lower heating value (LHV) while Second Law efficiency is calculated with exergy, which represents the inherent chemical energy available to produce propulsion. We find that First Law efficiency can deviate by as much as nine percentage points between fuels while Second Law efficiency exhibits a much smaller degree of variability. We also find that First and Second Law efficiency can be nearly the same for some fuels (methane and ethane) but differ substantially for other fuels (hydrogen and ethanol). The differences in First and Second Law efficiency are due to differences in LHV and exergy for a given fuel. In order to explain First Law efficiency differences between fuels as well as the differences between LHV and exergy, we introduce a new term: the molar expansion ratio (MER), defined as the ratio of product moles to reactant moles for complete stoichiometric combustion. We find that the MER is a useful expression for providing a physical explanation for fuel-specific efficiency differences as well as differences between First and Second Law efficiency. First and Second Law efficiency are affected by a number of other fuel-specific thermochemical properties, such as the ratio of specific heat and dissociation of combustion products.

  9. Combustion engineering issues for solid fuel systems

    SciTech Connect

    Bruce Miller; David Tillman

    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.

  10. Comparison of numerical simulation results for transport and thermodynamic properties of the solid fuels combustion products with experimental data

    NASA Astrophysics Data System (ADS)

    Shmelkov, Yuriy; Samujlov, Eugueny

    2012-04-01

    Comparison of calculation results of transport properties of the solid fuels combustion products was made with known experimental data. Calculation was made by means of the modified program TETRAN developed in G.M. Krzhizhanovsky Power Engineering Institute. The calculation was spent with chemical reactions and phase transformations occurring during combustion. Also ionization of products of solid fuels combustion products at high temperatures was taken into account. In the capacity of fuels various Russian coals and some other solid fuels were considered. As a result of density, viscosity and heat conductivity calculation of a gas phase of solid fuels combustion products the data has been obtained in a range of temperatures 500-20000 K. This comparison has shown good convergence of calculation results with experiment.

  11. Combustion improver fuel additive

    SciTech Connect

    Kitchen, G.H. III

    1986-04-29

    A fuel additive is described for improving the combustion efficiency and storage stability of stored fuel which is capable of reducing the amount of macroscopic sludge particles formed from polymerization reactions promoted by bacteria and oxidation in fuel and improving the combustion efficiency of the fuel and reducing the soot emissions and scale formation of such fuel in a combustion chamber when used in amounts of from about one part of additive composition to between 3000 to about 10,000 parts by weight of fuel and containing in parts by weight per 100 parts by weight of additive about 50 parts by weight of a polymerizate of ethylene diamine, about 15 parts by weight of a naphtha solvent, about 15 parts by weight of a polyalphaolefin based synthetic oil, about 0.05 parts by weight of a miscible biocide, and about 20 parts by weight of manganese linoleate.

  12. Combustion gas properties of various fuels of interest to gas turbine engineers

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    A series of computations were made using the gas property computational schemes of Gordon and McBride to compute the gas properties and species concentration of ASTM-Jet A and dry air. The computed gas thermodynamic properties in a revised graphical format which gives information which is useful to combustion engineers is presented. A series of reports covering the properties of many fuel and air combinations will be published. The graphical presentation displays on one chart of the output of hundreds of computer sheets. The reports will contain microfiche cards, from which complete tables and graphs can be obtained. The extent of the planned effort and is documented samples of the many tables and charts that will be available on the microfiche cards are presented.

  13. Fuel properties and combustion kinetics of hydrochar prepared by hydrothermal carbonization of bamboo.

    PubMed

    Yang, Wei; Wang, Hui; Zhang, Meng; Zhu, Jiayu; Zhou, Jie; Wu, Shengji

    2016-04-01

    Hydrothermal carbonization, an environmental friendly treatment method was employed to pretreat bamboo for hydrochar preparation in the present study. Hydrothermal carbonization could elevate the fuel properties and combustion behavior of bamboo. The combustion kinetic parameters of raw bamboo and hydrochars were calculated by a simple Arrhenius equation based on the thermogravimetric curves. Two distinct zones were observed for raw bamboo and hydrochars. The activation energies of raw bamboo in zone 1 and zone 2 were 109.5kJ/mol and 46.6kJ/mol, respectively, in the heating rate of 20°C/min. The activation energy of hydrochar in zone 1 increased at the hydrothermal carbonization temperature under 220°C and then decreased at higher hydrothermal carbonization temperature, due to the decomposition of relative reactive compounds in bamboo, and destruction of cellulose and hemicellulose structures, respectively. The activation energies of hydrochars in zone 2 were among 52.3-57.5kJ/mol, lower than that of lignin extracted from bamboo. PMID:26826960

  14. Fuel-Rich Catalytic Combustion

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Olson, Sandra L.

    1987-01-01

    Two-stage combustion system reduces particulate emissions. Program on catalytic oxidation of iso-octane demonstrates feasibility of two-stage combustion system for reducing particulate emissions. With fuel-rich (fuel/air equivalence ratios of 4.8 to 7.8) catalytic-combustion preburner as first stage, combustion process free of soot at reactor-outlet temperatures of 1,200 K or less.

  15. Study of influence of fuel on dielectric and ferroelectric properties of bismuth titanate ceramics synthesized using solution based combustion technique

    NASA Astrophysics Data System (ADS)

    Subohi, Oroosa; Kumar, G. S.; Malik, M. M.; Kurchania, Rajnish

    2015-03-01

    The effect of fuel characteristics on the processing and properties of bismuth titanate (BIT) ceramics obtained by solution combustion route using different fuels are reported in this paper. Dextrose, urea and glycine were used as fuel in this study. The obtained bismuth titanate ceramics were characterized by using XRD, SEM at different stages of sample preparation. It was observed that BIT obtained by using dextrose as fuel shows higher dielectric constant and higher remnant polarization due to smaller grain size and lesser c-axis growth as compared to the samples with urea and glycine as fuel. The electrical behavior of the samples with respect to temperature and frequency was also investigated to understand relaxation phenomenon.

  16. Combustion behavior of solid fuel ramjets

    NASA Technical Reports Server (NTRS)

    Netzer, D. W.; Binn, B. A.; Scott, W. E.; Metochianakis, M.

    1980-01-01

    Nonreacting flowfield characteristics and fundamental fuel properties are considered with respect to their use in estimating the obtainable combustion efficiency for fuels and/or combustor geometries. It is shown that near wall turbulence intensity in nonreacting flow appears to correlate reasonably well with the fuel regression pattern in identical geometries. The HTPB based fuels exhibit solid phase exothermic reactions in contrast to purely endothermic reactions for plexiglas. It is further shown that combustion pressure oscillations appear to be related to physically induced disturbances to the fluctuating shear layers at the fuel grain and aft mixing chamber inlets.

  17. Fuel-rich catalytic combustion of a high density fuel

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Merritt, Sylvia A.

    1993-01-01

    Fuel-rich catalytic combustion (ER is greater than 4) of the high density fuel exo-tetrahydrocyclopentadiene (JP-10) was studied over the equivalence ratio range 5.0 to 7.6, which yielded combustion temperatures of 1220 to 1120 K. The process produced soot-free gaseous products similar to those obtained with iso-octane and jet-A in previous studies. The measured combustion temperature agreed well with that calculated assuming soot was not a combustion product. The process raised the effective hydrogen/carbon (H/C) ratio from 1.6 to over 2.0, thus significantly improving the combustion properties of the fuel. At an equivalence ratio near 5.0, about 80 percent of the initial fuel carbon was in light gaseous products and about 20 percent in larger condensable molecules. Fuel-rich catalytic combustion has now been studied for three fuels with H/C ratios of 2.25 (iso-octane), 1.92 (jet-A), and 1.6 (JP-10). A comparison of the product distribution of these fuels shows that, in general, the measured concentrations of the combustion products were monotonic functions of the H/C ratio with the exception of hydrogen and ethylene. In these cases, data for JP-10 fell between iso-octane and jet-A rather than beyond jet-A. It is suggested that the ring cross-linking structure of JP-10 may be responsible for this behavior. All the fuels studied showed that the largest amounts of small hydrocarbon molecules and the smallest amounts of large condensable molecules occurred at the lower equivalence ratios. This corresponds to the highest combustion temperatures used in these studies. Although higher temperatures may improve this mix, the temperature is limited. First, the life of the present catalyst would be greatly shortened when operated at temperatures of 1300 K or greater. Second, fuel-rich catalytic combustion does not produce soot because the combustion temperatures used in the experiments were well below the threshold temperature (1350 K) for the formation of soot. Increasing the temperature above this value would remove the soot-free nature of the process. Since all the fuels studied show a similar breakdown of the primary fuel into smaller molecular combustion products, this technique can be applied to all hydrocarbon fuels.

  18. Fuel quality combustion analysis

    NASA Technical Reports Server (NTRS)

    Naegeli, D. W.; Moses, C. A.

    1979-01-01

    A high pressure research combustor operating over a wide range of burner inlet conditions was used to determine the effects of fuel molecular structure on soot formation. Six test fuels with equal hydrogen content (12.8%) were blended to stress different molecular components and final boiling points. The fuels containing high concentrations (20%) of polycyclic aromatics and partially saturated polycyclic structures such as tetralin, produced more soot than would be expected from a hydrogen content correlation for typical petroleum based fuels. Fuels containing naphthenes such as decalin agreed with the hydrogen content correlation. The contribution of polycyclic aromatics to soot formation was equivalent to a reduction in fuel hydrogen content of about one percent. The fuel sensitivity to soot formation due to the polycyclic aromatic contribution decreased as burner inlet pressure and fuel/air ratio increased.

  19. Thermodynamic and transport properties of air and its products of combustion with ASTMA-A-1 fuel and natural gas at 20, 30, and 40 atmospheres

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

    The isentropic exponent, molecular weight, viscosity, specific heat at constant pressure, thermal conductivity, Prandtl number, and enthalpy were calculated for air, the combustion products of ASTM-A-1 jet fuel and air, and the combustion products of natural gas and air. The properties were calculated over a temperature range from 300 to 2800 K in 100 K increments and for pressures of 20, 30 and 40 atmospheres. The data for natural gas and ASTM-A-1 were calculated for fuel-air ratios from zero to stoichiometric in 0.01 increments.

  20. Fuel and Combustion Characteristics of Organic Wastes

    NASA Astrophysics Data System (ADS)

    Namba, Kunihiko; Ida, Tamio

    From a viewpoint of environmental preservation and resource protection, the recycling of wastes has been promoting. Expectations to new energy resource are growing by decrease of fossil fuel. Biomass is one of new energies for prevent global warning. This study is an attempt to burn biomass lamps made from residues in order to thermally recycle waste products of drink industries. The pyrolytic properties of shochu dregs and used tea leaves were observed by thermo-gravimertic analysis (TG) to obtained fundamental data of drink waste pyrolysis. It observed that shochu dregs pyrolyze under lower temperature than used tea leaves. These wastes were compressed by hot press apparatus in the temperature range from 140 to 180 C for use as Bio-fuel (BF). The combustion behavior of BF was observed in fall-type electric furnace, where video-recording was carried out at sequential steps, such as ignition, visible envelope flame combustion and char combustion to obtain combustion characteristics such as ignition delay, visible flame combustion time and char combustion time.

  1. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, B.D.; Confer, G.L.; Zujing Shen; Hapeman, M.J.; Flynn, P.L.

    1993-12-21

    Apparatus and a method of introducing a primary fuel, which may be a coal water slurry, 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. 19 figures.

  2. Method of combustion for dual fuel engine

    DOEpatents

    Hsu, Bertrand D.; Confer, Gregory L.; Shen, Zujing; Hapeman, Martin J.; Flynn, Paul L.

    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.

  3. Combustor nozzle for a fuel-flexible combustion system

    DOEpatents

    Haynes, Joel Meier; Mosbacher, David Matthew; Janssen, Jonathan Sebastian; Iyer, Venkatraman Ananthakrishnan

    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.

  4. 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.

  5. Catalytic combustion of residual fuels

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  6. Evaporation and Combustion Characteristics of Multicomponent Fuels

    NASA Astrophysics Data System (ADS)

    Govindaraju, Pavan; Stagni, Alessandro; Ihme, Matthias

    2015-11-01

    Current generation fuels are mixtures of hundreds of complicated organic compounds and accurate modeling of their combustion characteristics provides fundamental physical insights which also help in the design of efficient combustors. This however requires accurate simulation of both evaporation and combustion processes, which, in case of such fuels, demands an approach based on calculating properties using only the information of functional groups present in the mixture. The presentation will elaborate on the assumptions and the framework utilized for evaporation and chemical mechanisms. We also present a comparison between various fuels used in the aviation industry as test cases while highlighting on their pros and cons. The focus of the talk will however be on the physical aspects captured using 1D simulations, i.e., preferential evaporation of each species, ignition parameters and emissions while justifying the numerical calculations with experimental data at each stage. Further work involving the coupling of flow with evaporation and combustion can be performed and we briefly discuss why a DNS is necessary to characterize the various combustion regimes. Federal Aviation Administration.

  7. 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

  8. Structural and magnetic properties of manganese zinc ferrite nanoparticles prepared by solution combustion method using mixture of fuels

    NASA Astrophysics Data System (ADS)

    Angadi, V. Jagadeesha; Rudraswamy, B.; Sadhana, K.; Praveena, K.

    2016-07-01

    The structural analysis and magnetic investigation Mn1-xZnxFe2O4 with stoichiometry (x=0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) were synthesized by solution combustion method using mixture of fuel this is first of its kind. As synthesized Mn-Zn nanoferrites were characterized by X-ray Diffractometer (XRD), Transmission electron microscopy (TEM) at room temperature. The magnetic domain relaxation was investigated by inductance spectroscopy (IS) and the observed magnetic domain relaxation frequency (fr) was increased with the increase in grain size. The Room temperature magnetic properties were studied using vibrating sample magnetometer (VSM). It was observed that the real and imaginary part of permeability (μ‧ and μ″), saturation magnetization (Ms), remanance magnetization (Mr) and magneton number (Mr/Ms) were decreases gradually with increasing Zn2+ concentration. The decrease in the saturation magnetization may be explained as, the Zn2+ concentration increases the relative number of ferric ions on the A sites diminishes and this reduces the A-B interaction. Hence synthesized materials are good for high frequency applications.

  9. The effect of fuel and sorbent properties on their partitioning between the flyash and bottom ash streams in fluidized bed combustion

    NASA Astrophysics Data System (ADS)

    Rozelle, Peter Lawrence

    2000-10-01

    The fluidized bed combustion process has been employed successfully in several applications, among which steam raising is notable. The use of circulating fluidized bed (CFB) combustion for steam and power generation offers a competitive alternative both in the United States and worldwide, yet there remain technical issues, which if addressed, can improve the competitive position of CFB boiler technology, and improve the operating economics of existing plants. Prominent among these technical issues are the performance of limestones and dolostones as sorbents for emissions control, and the ability of a plant's ash handling system to respond to changes in the fuel or sorbent used by the plant. Study of the effects of fuel and sorbent properties on the partitioning of their resultant bed particles between the ash streams, during the fluidized bed combustion process, has been carried out. This work used results from sorbent tests in a commercial CFB boiler and experimentation with laboratory fluid bed reactors. Sorbents varying in petrographic properties were used in the boiler tests as well as the laboratory testing. Fuels tested had varying distributions of ash content by specific gravity, and ranged in composite ash content from 25 to 49 wt%. Sorbent petrographic properties, described by a characteristic crystallite size, influenced the partitioning of calcium to the flyash and bottom ash streams of the boiler. Under the boiler conditions used for the sorbent tests, sorbent petrographic properties significantly influenced the sorbent consumption rate required by the boiler to maintain air quality compliance. Testing of a range of fuels was carried out in a laboratory fluid bed combustor. Ashing of different specific gravity fractions of the coarse fuel particles revealed a trend where higher specific gravity fractions of the fuel yielded coarse ash particles. A trend was found between increased presence of high ash content particles in a fuel, and increased production of bottom ash by the combustor. The results suggested that the distribution of ash content across the range of fuel particles, sorbent attrition properties, and the size classification characteristics of the system will influence the ash split produced by a fluid bed combustion system. (Abstract shortened by UMI.)

  10. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Beal, H.R.; Gralton, G.W.; Gronauer, T.W.; Liljedahl, G.N.; Love, B.F.

    1987-06-01

    Activities conducted under this contract include studies on the combustion and fireside behavior of numerous coal-water fuels (CWFs). The work has been broken down into the following areas: Task 1 -- Selection of Candidate Fuels; Task 2 -- Bench Scale Tests; Task 3 -- CWF Preparation and Supply; Task 4 -- Combustion Characterization; Task 5 -- Ash Deposition and Performance Testing; Task 6 -- Commercial Applications. This report covers Task 6, the study of commercial applications of CWFs as related to the technical and economic aspects of the conversion of existing boilers and heaters to CWF firing. This work involves the analysis of seven units of various sizes and configurations firing several selected CWFs. Three utility boilers, two industrial boilers, and two process heater designs are included. Each of the units was considered with four primary selected CWFs. A fifth fuel was considered for one of the utility units. A sixth fuel, a microfine grind CWF, was evaluated on two utility units and one industrial unit. The particular fuels were chosen with the objective of examining the effects of coal source, ash level, ash properties, and beneficiation on the CWF performance and economics of the seven units. 10 refs., 81 figs., 80 tabs.

  11. 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.

  12. 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.

  13. 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.

  14. 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).

  15. Engine combustion control via fuel reactivity stratification

    DOEpatents

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

    2015-07-14

    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 choosing 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).

  16. Gas turbine fuels and their influence on combustion

    SciTech Connect

    Odgers, J.; Kretschmer, D.

    1986-01-01

    This book discusses the general fuel situation and the occurrence and origin of fuels as both raw materials or synthesized products, and considers possible future research requirements necessary to ensure sufficient knowledge to the designer. After establishing the properties of fuels, the remainder of the book is devoted to assessing their effects upon gas turbine combustors. The fuels are considered in three groups - solids, liquids, and gases. For solid fuels, notes are included on direct firing, the use of slurries, indirect firing, and fluidized bed combustion. Liquid fuels include considerations of fuels derived from oil shales, tar sands, coal derivatives, and alcohols. Gaseous fuels run the gamut of very wide fuel compositions, ranging from high calorific fuels (above 20 MJ/m/sup 3/) to very low calorific fuels (less than 5 MJ/m/sup 3/). For all of these fuels, data are cited to enable changes in combustion behaviour to be assessed with respect to flame temperatures, flame stability and extinction, combustion efficiency and the occurrence of pollutants within the exhaust, heat transfer within the combustor and possible effects upon chamber life. Where the effects are serious, possible changes to the equipment are indicated.

  17. Diesel engine combustion of sunflower oil fuels

    SciTech Connect

    Zubik, J.; Sorenson, S.C.; Goering, C.E.

    1984-09-01

    The performance, combustion, and exhaust emissions of diesel fuel, a blend of 25% sunflower oil in diesel fuel, and sunflower oil methyl ester have been compared. All fuels performed satisfactorily in a direct injection diesel engine, with the fuels derived from sunflower oil giving somewhat higher cylinder pressures and rates of pressure rise due to a higher percentage of 'premixed' burning than the diesel fuel. General performance and emissions characteristics of the two fuels were comparable, with the oil based fuels giving lower smoke readings. 15 references.

  18. 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.

  19. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on Combustion Characterization of Beneficiated Coal-Based Fuels.'' The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE's laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  20. Combustion characteristics of gas turbine alternative fuels

    NASA Technical Reports Server (NTRS)

    Rollbuhler, R. James

    1987-01-01

    An experimental investigation was conducted to obtain combustion performance values for specific heavyend, 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, and inlet air temperatures. The combustion pressure, as well as the hardware, were kept nearly constant over the program test phase. Test results were obtained in regards to geometric temperature pattern factors as a function of combustor wall temperatures, the combustion gas temperature, and the combustion emissions, both as affected by the mass flow rate and fuel-to-air ratio. The synthetic fuels were reacted in the combustor such that for most tests their performance was as good, if not better, than the baseline gasoline or diesel fuel tests. The only detrimental effects were that at high inlet air temperature conditions, fuel decomposition occurred in the fuel atomizing nozzle passages resulting in blockage. And the nitrogen oxide emissions were above EPA limits at low flow rate and high operating temperature conditions.

  1. Banyan latex: a facile fuel for the multifunctional properties of MgO nanoparticles prepared via auto ignited combustion route

    NASA Astrophysics Data System (ADS)

    Kumar, M. R. Anil; Nagaswarupa, H. P.; Anantharaju, K. S.; Gurushantha, K.; Pratapkumar, C.; Prashantha, S. C.; Shashishekar, T. R.; Nagabhushana, H.; Sharma, S. C.; Vidya, Y. S.; Daruka Prasad, B.; Vivek Babu, C. S.; Vishnu Mahesh, K. R.

    2015-09-01

    MgO nanoparticles (MNPs) were prepared by a solution combustion route using banyan tree (BT) latex and glycine as fuels. The powder x-ray diffraction results indicate the formation of a single cubic phase and the crystallite size obtained from transmission electron microscopy was found to be ˜10-15 nm. Scanning electron microscopy result reveals spherical-shaped particles obtained with BT latex. However, in a chemical route, porous and agglomerated particles were obtained. The energy band gap of MNPs obtained using BT latex and a chemical route were found to be in the range 4.85-5.0 eV. Photoluminescence peaks observed at 473, 514, and 588 nm when excited at 433 nm, which were attributed to surface defects. The enhanced photocatalytic activities of spherical MgO were due to smaller crystallite size, higher surface defects, dye sensitization, and capability to reduce the electron-hole pair recombination. Further, green-synthesized MNPs exhibit superior antifungal activity against various plant pathogens. The present studies demonstrated a green engineering route for the synthesis of multifunctional MNPs using BT latex.

  2. 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.

  3. Survey of Hydrogen Combustion Properties

    NASA Technical Reports Server (NTRS)

    Drell, Isadore L; Belles, Frank E

    1958-01-01

    This literature digest of hydrogen-air combustion fundamentals presents data on flame temperature, burning velocity, quenching distance, flammability limits, ignition energy, flame stability, detonation, spontaneous ignition, and explosion limits. The data are assessed, recommended values are given, and relations among various combustion properties are discussed. New material presented includes: theoretical treatment of variation in spontaneous ignition lag with temperature, pressure, and composition, based on reaction kinetics of hydrogen-air composition range for 0.01 to 100 atmospheres and initial temperatures of 0 degrees to 1400 degrees k.

  4. Plasma enhancement of combustion of solid fuels

    SciTech Connect

    Askarova, A.S.; Karpenko, E.I.; Messerle, V.E.; Ustimenko, A.B.

    2006-03-15

    Plasma fuel systems that increase the coal burning efficiency are discussed. The systems were tested for fuel oil-free startup of boilers and stabilizating a pulverized-coal flame in power-generating boilers equipped with different types of burner and burning all types of power-generating coal. Plasma ignition, thermochemical treatment of an air-fuel mixture prior to combustion, and its burning in a power-generating boiler were numerically simulated. Environmental friendliness of the plasma technology was demonstrated.

  5. NASA broad-specification fuels combustion technology program

    NASA Technical Reports Server (NTRS)

    Fear, J. S.

    1984-01-01

    The NASA Broad-Specification Fuels Combustion Technology Program was initiated in response to concerns that the supply of high-quality petroleum middle distillates for jet fuel, abundant in the past, would diminish in availability toward the end of the century. The specific program objective is to evolve the combustion system technology required to use fuels with moderate ranges of broadened properties in the engines used on commercial jet aircraft. The first phase of the program, in which effects of the use of broadened-properties fuels were identified and technology with the potential to offset these effects was also identified, has been completed. The second phase, in which the technology identified in Phase 1 is being refined, will be completed within the next three months.

  6. Combustion and fuel characterization of coal-water fuels

    SciTech Connect

    Chow, O.K.; Gralton, G.W.; Lachowicz, Y.V.; Laflesh, R.C.; Levasseur, A.A.; Liljedahl, G.N.

    1989-02-01

    This five-year research project was established to provide sufficient data on coal-water fuel (CWF) chemical, physical, and combustion properties to assess the potential for commercial firing in furnaces designed for gas or oil firing. Extensive laboratory testing was performed at bench-scale, pilot-scale (4 {times} 10{sup 6}Btu/hr) and commercial-scale (25 {times} 10{sup 6} to 50 {times} 10{sup 6}Btu/hr) on a cross-section of CWFs. Fuel performance characteristics were assessed with respect to coal properties, level of coal beneficiation, and slurry formulation. The performance of four generic burner designs was also assessed. Boiler performance design models were applied to analyze the impacts associated with conversion of seven different generic unit designs to CWF firing. Equipment modifications, operating limitations, and retrofit costs were determined for each design when utilizing several CWFs. Unit performance analyses showed significantly better load capacity for utility and industrial boilers as the CWF feed coal ash content is reduced to 5% or 2.6%. In general, utility units had more attractive capacity limits and retrofit costs than the industrial boilers and process heaters studied. Economic analyses indicated that conversion to CWF firing generally becomes feasible when differential fuel costs are above $1.00/10{sup 6}Btu. 60 figs., 24 tabs.

  7. 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.

  8. 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.

  9. 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 γ-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

  10. FUEL NOX CONTROL BY CATALYTIC COMBUSTION

    EPA Science Inventory

    The report gives results of an experimental study to: (1) define operating conditions for catalytic combustors that give low levels of NOx emissions for fuelbound nitrogen compounds, and (2) quantitatively determine the fate of fuel nitrogen during catalytic combustion. Tests wer...

  11. 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...

  12. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  13. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  14. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  15. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  16. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  17. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  18. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  19. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  20. 30 CFR 57.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  1. 30 CFR 56.4103 - Fueling internal combustion engines.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts...

  2. Fuels Performance: Navigating the Intersection of Fuels and Combustion (Brochure)

    SciTech Connect

    Not Available

    2014-12-01

    Researchers at the National Renewable Energy Laboratory (NREL), the only national laboratory dedicated 100% to renewable energy and energy efficiency, recognize that engine and infrastructure compatibility can make or break the impact of even the most promising fuel. NREL and its industry partners navigate the intersection of fuel chemistry, ignition kinetics, combustion, and emissions, with innovative approaches to engines and fuels that meet drivers' expectations, while minimizing petroleum use and GHGs.

  3. 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.

  4. 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

  5. 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

  6. Plasma-aided solid fuel combustion

    SciTech Connect

    E.I. Karpenko; V.E. Messerle; A.B. Ustimenko

    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.

  7. Studies of oscillatory combustion and fuel vaporization

    NASA Technical Reports Server (NTRS)

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

    1972-01-01

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

  8. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion...

  9. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion...

  10. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion...

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion...

  12. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion...

  13. Combustion oscillation control by cyclic fuel injection

    SciTech Connect

    Richards, G.A.; Yip, M.J.; Robey, E.; Cowell, L.; Rawlins, D.

    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.

  14. Combustion oscillation control by cyclic fuel injection

    SciTech Connect

    Richards, G.A.; Yip, M.J.; Robey, E.; Cowell, L.; Rawlins, D.

    1997-04-01

    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 percent control fuel in a premix fuel nozzle is shown to reduce oscillating pressure amplitude by a factor of 0.30 (i.e., {minus}10 dB) at 300 Hz. Measurement of the oscillating heat release is also reported.

  15. 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.

  16. Fuel-NOx release during coal blends combustion

    SciTech Connect

    Qiu, J.; Zhu, Q.; Li, F.; Liu, Y.; Zheng, C.; Zeng, H.

    1999-07-01

    The emission of nitrogen oxides from coal combustion has a major environmental impact. Recently, a number of power stations have been successively burning blended coals, while meeting NOx emission limits. In this paper, the emission of nitrogen and NOx release during blended pulverized coal combustion have been investigated in a horizontal' electric heating reactor and a drop-tube furnace. Formation and conversion of the intermediate N0containing species as HCN and NHI were also measured. The influence of components coal properties on NO and char-NO has been analyzed. The nitrogen evolution of blended coals has no obvious linear relation with blended ratios. Fuel-NOx release from blended coal combustion take a longer time than that form single one. At high temperature, the reaction of the conversion from Char-N to NOx is diffusion control reaction. At low temperature, the reaction is under chemical control reaction, which is similar with the conversion of volatile-N to NOx.

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

    SciTech Connect

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

    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.

  18. Demonstration of catalytic combustion with residual fuel

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

    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.

  19. Oxygen enhanced switching to combustion of lower rank fuels

    DOEpatents

    Kobayashi, Hisashi; Bool, III, Lawrence E.; Wu, Kuang Tsai

    2004-03-02

    A furnace that combusts fuel, such as coal, of a given minimum energy content to obtain a stated minimum amount of energy per unit of time is enabled to combust fuel having a lower energy content, while still obtaining at least the stated minimum energy generation rate, by replacing a small amount of the combustion air fed to the furnace by oxygen. The replacement of oxygen for combustion air also provides reduction in the generation of NOx.

  20. 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.

  1. Water Interaction with Laboratory-Simulated Fossil Fuel Combustion Particles

    NASA Astrophysics Data System (ADS)

    Popovicheva, O. B.; Kireeva, E. D.; Shonija, N. K.; Khokhlova, T. D.

    2009-09-01

    To clarify the impact of fossil fuel combustion particles' composition on their capacity to take up water, we apply a laboratory approach in which the method of deposition of compounds, identified in the particulate coverage of diesel and aircraft engine soot particles, is developed. It is found that near-monolayer organic/inorganic coverage of the soot particles may be represented by three groups of fossil fuel combustion-derived particulate matter with respect to their Hansh's coefficients related to hydrophilic properties. Water adsorption measurements show that nonpolar organics (aliphatic and aromatic hydrocarbons) lead to hydrophobization of the soot surface. Acidic properties of organic compounds such as those of oxidized PAHs, ethers, ketones, aromatic, and aliphatic acids are related to higher water uptake, whereas inorganic acids and ionic compounds such as salts of organic acids are shown to be responsible for soot hydrophilization. This finding allows us to quantify the role of the chemical identity of soot surface compounds in water uptake and the water interaction with fossil fuel combustion particles in the humid atmosphere.

  2. Combustion characterization of beneficiated coal-based fuels

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-08-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, conbustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Sciences, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for the full-scale tests. Approximately nine BCFs will be in dry ultra-fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  3. Water interaction with laboratory-simulated fossil fuel combustion particles.

    PubMed

    Popovicheva, O B; Kireeva, E D; Shonija, N K; Khokhlova, T D

    2009-10-01

    To clarify the impact of fossil fuel combustion particles' composition on their capacity to take up water, we apply a laboratory approach in which the method of deposition of compounds, identified in the particulate coverage of diesel and aircraft engine soot particles, is developed. It is found that near-monolayer organic/inorganic coverage of the soot particles may be represented by three groups of fossil fuel combustion-derived particulate matter with respect to their Hansh's coefficients related to hydrophilic properties. Water adsorption measurements show that nonpolar organics (aliphatic and aromatic hydrocarbons) lead to hydrophobization of the soot surface. Acidic properties of organic compounds such as those of oxidized PAHs, ethers, ketones, aromatic, and aliphatic acids are related to higher water uptake, whereas inorganic acids and ionic compounds such as salts of organic acids are shown to be responsible for soot hydrophilization. This finding allows us to quantify the role of the chemical identity of soot surface compounds in water uptake and the water interaction with fossil fuel combustion particles in the humid atmosphere. PMID:19736954

  4. Fuel supply arrangement for internal combustion engine

    SciTech Connect

    Shimoda, S.; Izuo, M.; Nakao, Y.; Shoji, M.; Iida, M.

    1986-06-17

    A fuel supply arrangement is described for an internal combustion engine, comprising: an adjusting device for adjusting supply amount of fuel to the engine; an air temperature sensor for detecting temperature of intake air, which is provided in an intake passage of the engine; a correcting means for correctively controlling the adjusting device on the basis of an output of the air temperature sensor such that the supply amount of the fuel to the engine is decreased as the temperature of the intake air rises; a detecting means for detecting a specific engine operating condition where a temperature of the intake air corresponding to the output of the air temperature sensor is higher than an actual temperature of the intake air; and a restricting means for restricting corrective control of the correcting means in response to a detection output of the detecting means, with the detection output representing detection of the specific engine operating condition.

  5. Influence of combustion conditions and coal properties on physical properties of fly ash generated from pulverized coal combustion

    SciTech Connect

    Hiromi Shirai; Hirofumi Tsuji; Michitaka Ikeda; Toshinobu Kotsuji

    2009-07-15

    To develop combustion technology for upgrading the quality of fly ash, the influences of the coal properties, such as the size of pulverized coal particles and the two-stage combustion ratio during the combustion, on the fly ash properties were investigated using our test furnace. The particle size, density, specific surface area (obtained by the Blaine method), and shape of fly ash particles of seven types of coal were measured. It was confirmed that the size of pulverized coal particles affects the size of the ash particles. Regarding the coal properties, the fuel ratio affected the ash particle size distribution. The density and shape of the ash particles strongly depended on their ash size. Our results indicated that the shape of the ash particles and the concentration of unburned carbon affected the specific surface area. The influence of the two-stage combustion ratio was limited. 8 refs., 13 figs., 3 tabs.

  6. Combustion of unitary solid fuels in a liquid medium

    NASA Astrophysics Data System (ADS)

    Barsukov, V. D.; Goldaev, S. V.; Min'kova, N. P.; Mulenok, E. V.

    1993-04-01

    The conditions under which combustion of unitary solid fuels occurs in a liquid (water) medium are discussed. The physical prerequisites for maintaining stable combustion are determined. The necessary conditions and constraints, which, when satisfied, ensure underwater combustion along a flat surface of fuel, are formulated. Possible combustion regimes, differing by direction and rate of displacement of the boundary of the surface of gas formation, are analyzed as a function of the orientation of a semiinfinite flat sample. Experimental results confirming the existence of stable combustion of solid fuel directly in a water medium are presented.

  7. Influence of drop size distribution and fuel vapor fraction on premixed spray combustion

    NASA Astrophysics Data System (ADS)

    Machiroutu, Sridhar Venkatabojji

    Premixed spray combustion is affected by fuel and oxidizer properties, mixture equivalence ratio and spray quality. The spray quality is characterized by a mean droplet diameter (SMD) and a droplet size distribution (DSD). Prior experimental studies have considered only the influence of SMD, in part due to the difficulty in controlling the DSD independently. The present work provides experimental evidence demonstrating the effect of the fuel droplet size distribution and fuel vapor fraction on premixed spray combustion. Combustion experiments were performed in a pilot-ignited, continuous flow, tubular, vertical test rig wherein fuel sprays were injected into an air stream. A novel twin-atomizer technique that allowed control over overall equivalence ratio, SMD, DSD, and fuel vapor fraction of the premixed spray was used to generate test sprays. A line-of-sight, infrared (IR) extinction technique was developed to quantify the fuel vapor fraction in premixed sprays. Radial distributions of fuel vapor were evaluated using an 'onion peeling' deconvolution technique. Combustion of test sprays indicated flame propagation among regions of high fuel vapor fraction to generate a high rate of combustion. In lean premixed sprays, the presence of a low fuel vapor concentration does not impact the combustion process. Experimental evidence demonstrating the enhancement of flame propagation velocity for optimal SMDs of ethanol sprays has been found. It was observed that test sprays with narrower DSDs have faster burning rates and more complete combustion. The DSD of the sprays were characterized with a droplet surface-area-based standard deviation of the DSD.

  8. 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.

  9. Synthetic fuel aromaticity and staged combustion

    SciTech Connect

    Longanbach, J. R.; Chan, L. K.; Levy, A.

    1982-11-15

    Samples of middle and heavy SRC-II distillates were distilled into 50 C boiling point range fractions. These were characterized by measurements of their molecular weight, elemental analysis and basic nitrogen content and calculation of average molecular structures. The structures typically consisted of 1 to 3 aromatic rings fused to alicyclic rings with short, 1 to 3 carbon aliphatic side chains. The lower boiling fractions contained significant amounts (1 atom/molecule) of oxygen while the heavier fractions contained so few heteroatoms that they were essentially hydrocarbons. Laboratory scale oxidative-pyrolysis experiments were carried out at pyrolysis temperatures of 500 to 1100 C and oxygen concentrations from 0 to 100 percent of stoichiometry. Analysis of liquid products, collected in condensers cooled with liquid nitrogen showed that aromatization is a major reaction in the absence of oxygen. The oxygen-containing materials (phenolics) seem to be more resistant to thermal pyrolysis than unsubstituted aromatics. Nitrogen converts from basic to nonbasic forms at about 500 C. The nonbasic nitrogen is more stable and survives up to 700 C after which it is slowly removed. A recently constructed 50,000 Btu/hr staged combustor was used to study the chemistry of the nitrogen and aromatics. SRC II combustion was studied under fuel-rich, first-stage conditions at air/fuel ratios from 0.6 to 1.0 times stoichiometric. The chemistry of the fuel during combustion calls for further investigation in order to examine the mechanism by which HCN is evolved as a common intermediate for the formation of the nitrogen-containing gaseous combustion products. 25 references, 45 figures, 25 tables.

  10. 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.

  11. Carbonaceous fuel combustion with improved desulfurization

    DOEpatents

    Yang, Ralph T.; Shen, Ming-shing

    1980-01-01

    Lime utilization for sulfurous oxides adsorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. The iron oxide present in the spent limestone is found to catalyze the regeneration rate of the spent limestone in a reducing environment. Thus both the calcium and iron components may be recycled.

  12. 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.

  13. Fuel-rich catalytic combustion of Jet-A fuel-equivalence ratios 5.0 to 8.0

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Gracia-Salcedo, Carmen M.

    1989-01-01

    Fuel-rich catalytic combustion (E.R. greater than 5.0) is a unique technique for preheating a hydrocarbon fuel to temperatures much higher than those obtained by conventional heat exchangers. In addition to producing very reactive molecules, the process upgrades the structure of the fuel by the formation of hydrogen and smaller hydrocarbons and produces a cleaner burning fuel by removing some of the fuel carbon from the soot formation chain. With fuel-rich catalytic combustion as the first stage of a two stage combustion system, enhanced fuel properties can be utilized by both high speed engines, where time for ignition and complete combustion is limited, and engines where emission of thermal NO sub x is critical. Two-stage combustion (rich-lean) has been shown to be effective for NO sub x reduction in stationary burners where residence times are long enough to burn-up the soot formed in the first stage. Such residence times are not available in aircraft engines. Thus, the soot-free nature of the present process is critical for high speed engines. The successful application of fuel-rich catalytic combustion to Jet-A, a multicomponent fuel used in gas turbine combustors, is discusssed.

  14. 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.

  15. Self-oscillations of an unstable fuel combustion in the combustion chamber of a liquid-propellant rocket engine

    NASA Astrophysics Data System (ADS)

    Gotsulenko, V. V.; Gotsulenko, V. N.

    2013-01-01

    The form of the self-oscillations of a vibrating combustion of a fuel in the combustion chamber of a liquidpropellant rocket engine, caused by the fuel-combustion lag and the heat release, was determined. The character of change in these self-oscillations with increase in the time of the fuel-combustion lag was investigated.

  16. Method of reducing the oxides of nitrogen in fossil fuels combustion and combustion effluents using amine compounds

    SciTech Connect

    Turchan, O.C.

    1990-07-24

    This patent describes a process for the reduction of oxides of nitrogen formed in the combustion of fossil fuels, within a fuel combustion reaction zone of a fossil fuels fired combustion apparatus or combustion device. The oxides of nitrogen reduction process comprises: the step of interjecting an admixture of oxides of nitrogen reducing agents consisting essentially of methylamine, ethylamine, ethylenediamine, diethylenetriamine, aniline, monoethylaniline, toluidine and xylidine, interjected individually or in any combination into the the fuel combustion reaction zone containing combustion fuel, combustion air and products of fuel combustion, including the oxides of nitrogen generated in the combustion of the fossil fuels, wherein the the admixture of oxides of nitrogen reducing agents react with the the oxides of nitrogen generated within the the fuel combustion reaction zone.

  17. Research program on reduced combustion chamber heat loss effects on alternative fuel combustion

    SciTech Connect

    Daby, E.E.; Garwin, I.J.; Havstad, P.H.; Hunter, C.E.

    1988-10-01

    A research program was conducted to determine the effects of thermal barriers in the combustion chamber of a diesel engine on the combustion and emissions of selected alternative fuels. Comparison of steady state fuel economy, exhaust emissions, and combustion data of heat insulated, baseline water-cooled, and high compression ratio engines were made using three fuels. Fuels believed to be representative of the year 2000 fuel were selected for the study. In fact, the light cycle oil fuel used was similar to CAPE.32 fuel (No. 6). Ceramic coatings and solid ceramic inserts were used to insulate the combustion chamber of the heat insulated, uncooled engine. Fuel economy and NOx emissions were generally lower for the heat insulated, uncooled engine than for the baseline engine and high compression water-cooled engine. Light load hydrocarbons were lower for the high compression ratio engine than for those of the baseline engine; however, hydrocarbon emissions for the heat insulated engine were higher than those of the baseline engine over the complete range of engine operating conditions tested. Heat insulating the combustion chamber and operating the water-cooled engine at elevated intake air temperature and high compression ratio reduced ignition delay and premixed combustion while increasing the amount of diffusion combustion. Further optimization of the combustion chamber, air motion, and the injection system of the heat insulated, uncooled engine may result in additional reductions in exhaust emissions not observed during this study. 59 figs., 2 tabs.

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

    SciTech Connect

    Colaluca, M.A.; Caraway, J.P.

    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.

  19. Basic Considerations in the Combustion of Hydrocarbon Fuels with Air

    NASA Technical Reports Server (NTRS)

    Barnett, Henry C; Hibbard, Robert R

    1957-01-01

    Basic combustion research is collected, collated, and interpreted as it applies to flight propulsion. The following fundamental processes are treated in separate chapters: atomization and evaporation of liquid fuels, flow and mixing processes in combustion chambers, ignition and flammability of hydrocarbon fuels, laminar flame propagation, turbulent flames, flame stabilization, diffusion flames, oscillations in combustors, and smoke and coke formation in the combustion of hydrocarbon-air mixtures. Theoretical background, basic experimental data, and practical significance to flight propulsion are presented.

  20. 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.

  1. LIEKKI and JALO: Combustion and fuel conversion

    NASA Astrophysics Data System (ADS)

    Grace, Thomas M.; Renz, Ulrich; Sarofim, Adel F.

    LIEKKI and JALO are well conceived and structured programs designed to strengthen Finland's special needs in combustion and gasification to utilize a diversity of fuels, increase the ratio of electrical to heat output, and to support the export market. Started in 1988, these two programs provide models of how universities, Technical research center's laboratories (VTT's), and industry can collaborate successfully in order to achieve national goals. The research is focused on long term goals in certain targeted niche areas. This is an effective way to use limited resources. The niche areas were chosen in a rational manner and appear to be appropriate for Finland. The LIEKKl and JALO programs have helped pull together research efforts that were previously more fragmented. For example, the combustion modeling area still appears fragmented. Individual project objectives should be tied to program goals at a very early stage to provide sharper focusing to the research. Both the LIEKKl and JALO programs appear to be strongly endorsed by industry. Industrial members of the Executive Committees were very supportive of these programs. There are good mechanisms for technology transfer in place, and the programs provide opportunities to establish good interfaces between industrial people and the individual researchers. The interest of industry is shown by the large number of applied projects that are supported by industry. This demonstrates the relevancy of the programs. There is a strong interaction between the JALO program and industry in black liquor gasification.

  2. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 17, April--June 1993

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-08-01

    Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1993, the following technical progress was made: Completed modeling calculations of coal mineral matter transformations, deposition behavior, and heat transfer impacts of six test fuels; and ran pilot-scale tests of Upper Freeport feed coal, microagglomerate product, and mulled product.

  3. Combustion mechanism of liquid fuel spray in a gaseous flame

    NASA Astrophysics Data System (ADS)

    Nakamura, Mariko; Akamatsu, Fumiteru; Kurose, Ryoichi; Katsuki, Masashi

    2005-12-01

    Two-dimensional direct numerical simulation is applied to spray flames stabilized in a laminar counterflow, and the detailed behavior is studied in terms of the droplet group combustion. The stretch ratio of the laminar counterflow is 40 l/s. (C10H22) is used as a liquid spray fuel, and a one-step global reaction is employed for the combustion reaction model. The results show that with increasing the issued liquid fuel mass fraction, two types of spray combustion appear in front of and inside the high gaseous temperature region, i.e., "premixed-like combustion" and "diffusion-like combustion," respectively. A droplet group combustion behavior is observed in the diffusion-like combustion region. This diffusion-like combustion, however, disappears when the issued droplet size becomes small, because the droplets complete their evaporation before entering into the high gaseous temperature region. The droplet group combustion tends to reduce the gaseous temperature. This is caused mainly by the suppression of combustion reaction due to the lack of oxygen and partially by the energy exchange through the convective heat transfer between droplets and gaseous phase. The gaseous temperature reduction is promoted by the latent heat of vaporization of the droplets. The use of the parcel approach has a risk of causing a delay of combustion reaction, since the partial fuel vapor pressure increases at limited locations, which suppresses the global droplet evaporation rate.

  4. Advanced Combustion and Fuels; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Zigler, Brad

    2015-06-08

    Presented at the U.S. Department of Energy Vehicle Technologies Office 2015 Annual Merit Review and Peer Evaluation Meeting, held June 8-12, 2015, in Arlington, Virginia. It addresses technical barriers of inadequate data and predictive tools for fuel and lubricant effects on advanced combustion engines, with the strategy being through collaboration, develop techniques, tools, and data to quantify critical fuel physico-chemical effects to enable development of advanced combustion engines that use alternative fuels.

  5. Combustion system for hybrid solar fossil fuel receiver

    DOEpatents

    Mehos, Mark S.; Anselmo, Kenneth M.; Moreno, James B.; Andraka, Charles E.; Rawlinson, K. Scott; Corey, John; Bohn, Mark S.

    2004-05-25

    A combustion system for a hybrid solar receiver comprises a pre-mixer which combines air and fuel to form an air-fuel mixture. The mixture is introduced tangentially into a cooling jacket. A burner plenum is fluidically connected to the cooling jacket such that the burner plenum and the cooling jacket are arranged in thermal contact with one another. The air-fuel mixture flows through the cooling jacket cooling the burner plenum to reduce pre-ignition of the air-fuel mixture in the burner plenum. A combustion chamber is operatively associated with and open to the burner plenum to receive the air-fuel mixture from the burner plenum. An igniter is operatively positioned in the combustion chamber to combust the air-fuel mixture, releasing heat. A recuperator is operatively associated with the burner plenum and the combustion chamber and pre-heats the air-fuel mixture in the burner plenum with heat from the combustion chamber. A heat-exchanger is operatively associated and in thermal contact with the combustion chamber. The heat-exchanger provides heat for the hybrid solar receiver.

  6. 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

  7. The Impact of Alternative Fuels on Combustion Kinetics

    SciTech Connect

    Pitz, W J; Westbrook, C K

    2009-07-30

    The research targets the development of detailed kinetic models to quantitatively characterize the impact of alternative fuels on the performance of Navy turbines and diesel engines. Such impacts include kinetic properties such as cetane number, flame speed, and emissions as well as physical properties such as the impact of boiling point distributions on fuel vaporization and mixing. The primary focus will be Fischer-Tropsch liquids made from natural gas, coal or biomass. The models will include both the effects of operation with these alternative fuels as well as blends of these fuels with conventional petroleum-based fuels. The team will develop the requisite kinetic rules for specific reaction types and incorporate these into detailed kinetic mechanisms to predict the combustion performance of neat alternative fuels as well as blends of these fuels with conventional fuels. Reduced kinetic models will be then developed to allow solution of the coupled kinetics/transport problems. This is a collaboration between the Colorado School of Mines (CSM) and the Lawrence Livermore National Laboratory (LLNL). The CSM/LLNL team plans to build on the substantial progress made in recent years in developing accurate detailed chemical mechanisms for the oxidation and pyrolysis of conventional fuels. Particular emphasis will be placed upon reactions of the isoalkanes and the daughter radicals, especially tertiary radicals, formed by abstraction from the isoalkanes. The various components of the program are described. We have been developing the kinetic models for two iso-dodecane molecules, using the same kinetic modeling formalisms that were developed for the gasoline and diesel primary reference fuels. These mechanisms, and the thermochemical and transport coefficient submodels for them, are very close to completion at the time of this report, and we expect them to be available for kinetic simulations early in the coming year. They will provide a basis for prediction and selection of desirable F-T molecules for use in jet engine simulations, where we should be able to predict the ignition, combustion and emissions characteristics of proposed fuel components. These mechanisms include the reactions and chemical species needed to describe high temperature phenomena such as shock tube ignition and flammability behavior, and they will also include low temperature kinetics to describe other ignition phenomena such as compression ignition and knocking. During the past years, our hydrocarbon kinetics modeling group at LLNL has focused a great deal on fuels typical of gasoline and diesel fuel. About 10 years ago, we developed kinetic models for the fuel octane primary reference fuels, n-heptane [1] and iso-octane [2], which have 7 and 8 carbon atoms and are therefore representative of typical gasoline fuels. N-heptane represents the low limit of knock resistance with an octane number of 0, while iso-octane is very knock resistant with an octane number of 100. High knock resistance in iso-octane was attributed largely to the large fraction of primary C-H bonds in the molecule, including 15 of the 18 C-H bonds, and the high bond energy of these primary bonds plays a large role in this knock resistance. In contrast, in the much more ignitable n-heptane, 10 of its 16 C-H bonds are much less strongly bound secondary C-H bonds, leading to its very low octane number. All of these factors, as well as a similarly complex kinetic description of the equally important role of the transition state rings that transfer H atoms within the reacting fuel molecules, were quantified and collected into large kinetic reaction mechanisms that are used by many researchers in the fuel chemistry world.

  8. Converting a fuel to combustible gas

    SciTech Connect

    Moss, G.

    1985-04-02

    A sulfur-containing fuel is passed into a first fluidized bed containing CaSO/sub 4/ and CaO and an oxygen-transfer mediator (e.g. H/sub 2/) whereby the fuel is converted to combustible gas, some CaSO/sub 4/ being reduced to CaS and sulfur being fixed as CaS by reaction with CaO. Bed particles pass from the bottom layer of the first bed into the bottom layer of the second bed which is fluidized by air at conditions such that some, but not all of the CaS is selectively oxidized to CaSO/sub 4/ with no liberation of sulfur moieties. Bed particles pass from the bottom layer of second bed to the bottom layer of a third bed optionally after passage via a fourth bed between the second and third beds. In the third bed particles are fluidized with air to convert CaS selectively to CaSO/sub 4/ with no liberation of sulfur moiety whereby to raise the particles' temperature sufficiently above that of the first bed that particles passing from the bottom layer of the third bed into the bottom layer of the first bed provide sufficient sensible heat to maintain the fuel conversion temperature of the first bed. In the fourth bed particles are fluidized with air under such conditions that sulfur moiety is liberated, preferably at a rate which approximately equals the rate of sulfur-capture in the first bed whereby to maintain approximately a constant amount of reactive CaO in the beds for sulfur-capture in the first bed.

  9. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 14, July--September 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-02-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; published two technical papers at conferences; and prepared for upcoming tests of new BCFs being produced.

  10. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 12, January--March 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1992-08-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed editing of the fifth quarterly report and sent it to the publishing office; and prepared two technical papers for conferences.

  11. 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 from the nozzle. To obtain a stable flame for a low glycerol concentration solution, t-butanol or ethanol was added as an additive. Experiments showed that an attached flame can be obtained by burning a mixture of 8.3 wt% t-butanol, 30 wt% glycerol and 61.7 wt% water (B8.3/G30) or 10 wt% ethanol, 30 wt% glycerol and 60 wt% water (E10/G30) under oxy-fired condition. The flame stability for B8.3/G30 and E10/G30 was characterized under 100% and 85% swirl flow conditions. Under 100% swirl flow condition, the blow-off limits are approximately the same for both cases. Under 85% swirl, the blow-off limits for B8.3/G30 are much lower in the low flow rate region. Additionally, the lift-off limits for B8.3/G30 are lower than those for E10/G30, which means the flame stability for B8.3/G30 is better. To study the flame structure, contours of temperature across the chamber's centerline were obtained for four attached flames. It was found that the flame becomes narrower as the swirl intensity decreases. A high temperature zone in the inner recirculation zone (IRZ) is formed for the four flames. This hot zone is critical to provide heat to vaporize the glycerol in near burner region, so that flame can be attached on the nozzle. For practical purposes, a PRB coal water slurry was studied in terms of preparation, characterization, atomization and combustion. A procedure to prepare stable coal water slurry from PRB coal was developed. Triton X-100 is a good nonionic surfactant for PRB coal. On the contrary, PSS, which is ionic, is not effective for PRB coal. Due to the hydrophilic surface property of PRB coal, the maximum loading of the coal in slurry can only reach 50 wt%. The viscosities of slurries containing various concentrations of Triton X-100 were measured. To deliver the slurry in a burner, two types of two fluid nozzles -- internal mixing and external mixing -- were investigated and both nozzles were able to generate a spray with good quality. Preliminary oxy-combustion experiments were successfully conducted. Due to the high swirl flow in the combustor, the nozzle overheated which caused clogging. Additional research is needed to solve this issue and characterize the flame systematically.

  12. 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.

  13. Engine combustion control at low loads via fuel reactivity stratification

    SciTech Connect

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

    2014-10-07

    A compression ignition (diesel) engine uses two or more fuel charges during a combustion cycle, with the fuel charges having two or more reactivities (e.g., different cetane numbers), in order to control the timing and duration of combustion. By appropriately choosing 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). At low load and no load (idling) conditions, the aforementioned results are attained by restricting airflow to the combustion chamber during the intake stroke (as by throttling the incoming air at or prior to the combustion chamber's intake port) so that the cylinder air pressure is below ambient pressure at the start of the compression stroke.

  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. 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...

  16. Combustion of Condensed Phase Alternative Fuels in an Acoustic Field

    NASA Astrophysics Data System (ADS)

    Rodriguez, Juan; Mao, Hann-Shin; Teshome, Sophonias; Pezeshkian, Alec; Smith, Owen; Karagozian, Ann

    2007-11-01

    This experimental study focused on fuel droplet combustion characteristics for various liquids during exposure to external acoustical perturbations. Emphasis in the present study was placed on the combustion of a number of alternative liquid fuels, including ethanol, methanol, aviation fuels, and blends of aviation fuel and liquid synthetic fuel derived from coal gasification via the Fischer-Tropsch process. The study examined combustion during excitation conditions in which the droplet was situated at or near a velocity antinode (pressure node) and at or near a velocity node (pressure antinode). During acoustic excitation of burning droplets, flame orientation was consistent with the sign of the acoustic radiation force acting on the burning system, creating conditions where the flame deflection switched, depending on the relative location of the droplet. Differences in burning rates, the degree and orientation of flame deflection, and flame extinction mechanisms were identified for the range of fuels and acoustic excitation conditions.

  17. Broad specification fuels combustion technology program

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    Design and development efforts to evolve promising aircraft gas turbine combustor configurations for burning broadened-properties fuels were discussed. Design and experimental evaluations of three different combustor concepts in sector combustor rig tests was conducted. The combustor concepts were a state of the art single-annular combustor, a staged double-annular combustor, and a short single-annular combustor with variable geometry to control primary zone stoichiometry. A total of 25 different configurations of the three combustor concepts were evaluated. Testing was conducted over the full range of CF6-80A engine combustor inlet conditions, using four fuels containing between 12% and 14% hydrogen by weight. Good progress was made toward meeting specific program emissions and performance goals with each of the three combustor concepts. The effects of reduced fuel hydrogen content, including increased flame radiation, liner metal temperature, smoke, and NOx emissions were documented. The most significant effect on the baseline combustor was a projected 33% life reduction, for a reduction from 14% to 13% fuel hydrogen content, due to increased liner temperatures.

  18. Combustion of liquid-fuel droplets in supercritical conditions

    SciTech Connect

    Shuen, J.S. ); Yang, Y.; Hsiao, C.C. )

    1992-06-01

    This paper reports on a comprehensive analysis of liquid-fuel droplet combustion in both subcritical and supercritical environments which has been conducted. The formulation is based on the complete conservation equations for both gas and liquid phases, and accommodates variably thermophysical properties, finite-rate chemical kinetics, and a full treatment of liquid-vapor phase equilibrium at the droplet 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.

  19. Fish oil as an alternative fuel for internal combustion engines

    SciTech Connect

    Blythe, N.X.

    1996-12-31

    This paper presents the results of combustion studies performed with fish oil and fish oil/diesel fuel blends in a medium speed, two cycle, opposed piston engine. Performance and emissions results with blends from 10% to 100% fish oil in diesel fuel are presented. Combustion cycle analysis data comparisons are made between fish oil and diesel fuel operation. Component inspection results and analysis of deposits found in the engine after the tests are also presented. Finally, comparisons between fish oil and other biodiesel fuels are made.

  20. 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.

  1. Fuel Vapor Pressures and the Relation of Vapor Pressure to the Preparation of Fuel for Combustion in Fuel Injection Engines

    NASA Technical Reports Server (NTRS)

    Joachim, William F; Rothrock, A M

    1930-01-01

    This investigation on the vapor pressure of fuels was conducted in connection with the general research on combustion in fuel injection engines. The purpose of the investigation was to study the effects of high temperatures such as exist during the first stages of injection on the vapor pressures of several fuels and certain fuel mixtures, and the relation of these vapor pressures to the preparation of the fuel for combustion in high-speed fuel injection engines.

  2. Stabilization Of Combustion Of Sprayed Fuel

    NASA Technical Reports Server (NTRS)

    Voecks, Gerald E.; Jan, Darrell L.

    1995-01-01

    Several modifications of nozzle spraying liquid propellant into combustion chamber proposed to stabilize combustion. Proposed changes in design of nozzle alter flow field in combustion chamber, according to fluid-mechanical principles, in such way as to suppress oscillations. Various alternative nozzle configurations include bluff or toroidal body to generate turbulence. Other features helping to suppress oscillations include down-stream recirculation zones, baffles, and damping cavities. Similar modifications help to suppress oscillations in industrial combustion chambers and in commercial and domestic oil-burning furnaces.

  3. Solid fuel combustion system for gas turbine engine

    DOEpatents

    Wilkes, Colin; Mongia, Hukam C.

    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.

  4. A Nonlinear Model for Fuel Atomization in Spray Combustion

    NASA Technical Reports Server (NTRS)

    Liu, Nan-Suey (Technical Monitor); Ibrahim, Essam A.; Sree, Dave

    2003-01-01

    Most gas turbine combustion codes rely on ad-hoc statistical assumptions regarding the outcome of fuel atomization processes. The modeling effort proposed in this project is aimed at developing a realistic model to produce accurate predictions of fuel atomization parameters. The model involves application of the nonlinear stability theory to analyze the instability and subsequent disintegration of the liquid fuel sheet that is produced by fuel injection nozzles in gas turbine combustors. The fuel sheet is atomized into a multiplicity of small drops of large surface area to volume ratio to enhance the evaporation rate and combustion performance. The proposed model will effect predictions of fuel sheet atomization parameters such as drop size, velocity, and orientation as well as sheet penetration depth, breakup time and thickness. These parameters are essential for combustion simulation codes to perform a controlled and optimized design of gas turbine fuel injectors. Optimizing fuel injection processes is crucial to improving combustion efficiency and hence reducing fuel consumption and pollutants emissions.

  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. Investigation of combustion characteristics of methane-hydrogen fuels

    NASA Astrophysics Data System (ADS)

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

    2015-01-01

    Numerical investigations of combustion characteristics of methane-hydrogen fuel used at present in tube furnaces of some petroleum refineries are carried out and possible problems related to change-over of existing furnaces from natural gas to methane-hydrogen fuel are analyzed. The effect of the composition of the blended fuel, associated temperature and emissivity of combustion products, temperature of combustion chamber walls, mean beam length, and heat release on variation in the radiation heat flux is investigated. The methane concentration varied from 0 to 100%. The investigations were carried out both at arbitrary given gas temperatures and at effective temperatures determined based on solving a set of equations at various heat-release rates of the combustion chamber and depended on the adiabatic combustion temperature and the temperature at the chamber output. The approximation dependence for estimation of the radiation heat exchange rate in the radiant chamber of the furnace at change-over to fuel with a greater hydrogen content is obtained. Hottel data were applied in the present work in connection with the impossibility to use approximated formulas recommended by the normative method for heat calculation of boilers to determine the gas emissivity, which are limited by the relationship of partial pressures of water steam and carbon dioxide in combustion products . The effect of the methane-hydrogen fuel on the equilibrium concentration of nitrogen oxides is also investigated.

  7. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 18, July--September 1993

    SciTech Connect

    Chow, O.K.; Hargrove, M.J.

    1993-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1993, the following technical progress was made: Continued with data and sample analysis from the pilot-scale tests of Upper Freeport feed coal, air-dried and mulled microagglomerate products; air-dried Pittsburgh No. 8 as-is and mulled products for upcoming Task 3 combustion testing; and prepared two abstracts for presentation for the March 1 994 Coal Utilization and Fuel Systems Conference.

  8. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 6, July 1990--September 1990

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a three-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are being run at the cleaning facility in Homer City, Pennsylvania, to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CVVT) or a dry microfine pulverized coal (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Science, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFS, and two conventionally cleaned coals for full-scale tests. Approximately, nine BCFs will be in dry microfine coal (DMPC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  9. 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...

  10. FUEL INTERCHANGEABILITY FOR LEAN PREMIXED COMBUSTION IN GAS TURBINE ENGINES

    SciTech Connect

    Don Ferguson; Geo. A. Richard; Doug Straub

    2008-06-13

    In response to environmental concerns of NOx emissions, gas turbine manufacturers have developed engines that operate under lean, pre-mixed fuel and air conditions. While this has proven to reduce NOx emissions by lowering peak flame temperatures, it is not without its limitations as engines utilizing this technology are more susceptible to combustion dynamics. Although dependent on a number of mechanisms, changes in fuel composition can alter the dynamic response of a given combustion system. This is of particular interest as increases in demand of domestic natural gas have fueled efforts to utilize alternatives such as coal derived syngas, imported liquefied natural gas and hydrogen or hydrogen augmented fuels. However, prior to changing the fuel supply end-users need to understand how their system will respond. A variety of historical parameters have been utilized to determine fuel interchangeability such as Wobbe and Weaver Indices, however these parameters were never optimized for today’s engines operating under lean pre-mixed combustion. This paper provides a discussion of currently available parameters to describe fuel interchangeability. Through the analysis of the dynamic response of a lab-scale Rijke tube combustor operating on various fuel blends, it is shown that commonly used indices are inadequate for describing combustion specific phenomena.

  11. Combustion of alternate liquid fuels in high efficiency boilers

    SciTech Connect

    Murphy, E.T.

    1983-06-01

    Alternate Liquid Fuel (ALF) is a ''non-critical'' fuel oil substitute formulated by selectively blending feedstocks of recycled solvents, alcohols, mineral spirits and other combustible liquids with substandard conventional fuel oils obtained from government surplus or purchased on the spot market. Typical feedstocks are listed on Table I. These combustible liquids, reclaimed from waste streams, are generated by petro-chemical, cosmetic, pharmaceutical, electronic, environmental recovery and other industries and government (mostly military) sources. The raw waste feedstocks collected from these sources are carefully segregated, cleaned up (of suspended solids and non-combustibles) and monitored by BNL and vendors to preclude feedstocks containing halogenated hydrocarbons, PCB's, heavy metals and other toxics in excess of prescribed levels. The resulting combustible feedstocks are purchased by BNL as a boiler fuel at prices 25 to 50 percent or more below conventional fuel oil market prices. Brookhaven National Laboratory (BNL) began testing ALF on an experimental basis in 1973, in an effort to reduce the Laboratory's rapidly escalating fuel oil bills. Based on accrued experience from the tests, a 40,000 gallon per day pilot processing system was constructed in 1976. Successful operation and full scale firing of ALF prompted to BNL to build a 700,000 gallon per day processing system in 1978, and to modify the existing Central Steam Facility fuel train to accommodate a wider range of liquid fuels in 1982.

  12. Influence of pH and fuels on the combustion synthesis, structural, morphological, electrical and magnetic properties of CoFe{sub 2}O{sub 4} nanoparticles

    SciTech Connect

    Shanmugavani, A.; Selvan, R.Kalai; Layek, Samar; Vasylechko, Leonid; Sanjeeviraja, C.

    2015-11-15

    Nanocrystalline spinel cobalt ferrite particles are synthesized by simple combustion method using aspartic acid and glycine as fuels. The single phase cubic structure of CoFe{sub 2}O{sub 4} is revealed through X-ray diffraction analysis (XRD). Further the Rietveld refinement confirms the formation of inverse spinel structure of CoFe{sub 2}O{sub 4}. The characteristic functional groups of Co–O and Fe–O are identified from Fourier Transform Infrared (FT-IR) analysis. Uniform distribution of of nearly spherical particles with the size range of 40–80 nm is identified through field emission scanning electron microscope (FESEM) images. The calculated DC conductivity is 1.469 × 10{sup −7} and 2.214 × 10{sup −8} S cm{sup −1}, for CoFe{sub 2}O{sub 4} synthesized using aspartic acid and glycine, respectively. The dielectric behavior obeys the Maxwell–Wagner interfacial polarization. The ferromagnetic behavior of CoFe{sub 2}O{sub 4} is identified using VSM analysis and the calculated coercivity is 27 Oe and saturation magnetization is 68 emu/g.

  13. Superheated fuel injection for combustion of liquid-solid slurries

    DOEpatents

    Robben, F.A.

    1984-10-19

    A method and device are claimed for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal. 2 figs., 2 tabs.

  14. Superheated fuel injection for combustion of liquid-solid slurries

    DOEpatents

    Robben, Franklin A.

    1985-01-01

    A method and device for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal.

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

    SciTech Connect

    Ra, Youngchul; Reitz, Rolf D.

    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)

  16. 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.

  17. 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.

  18. Combustion fundamentals of pyrolysis oil based fuels

    SciTech Connect

    Calabria, R.; Chiariello, F.; Massoli, P.

    2007-04-15

    The combustion behavior of emulsions of pyrolysis oil in commercial diesel oil was studied. The emulsions were different in terms of concentration and size of the dispersed phase. The study was carried out in a single droplet combustion chamber. The size of droplets varied between 400 {mu}m and 1200 {mu}m. They were suspended to a bare thermocouple and, hence, their temperature during combustion was measured. High-speed digital shadowgraphy was used to follow droplets evolution. The main features of the droplet combustion were recognized. The general combustion behavior of emulsions is intermediate with respect to pure PO and commercial diesel oil. Emulsion droplets underwent strong swelling and microexplosion phenomena. However, under the investigated conditions, the microexplosions were ineffective in destroying droplets. The size distribution of the dispersed PO droplets in the range 3-10 {mu}m was not effective either for determining the overall thermal behavior or for the efficacy of the microexplosions. The homogeneous combustion phase resulted identical for emulsions and diesel oil despite the emulsions composition (i.e., concentration of oil, surfactant and co-surfactant, as well as the size of the oil droplets in the emulsion) and the different structure of the flame and also its time and spatial evolution. (author)

  19. Oxy-fuel combustion with integrated pollution control

    DOEpatents

    Patrick, Brian R.; Ochs, Thomas Lilburn; Summers, Cathy Ann; Oryshchyn, Danylo B.; Turner, Paul Chandler

    2012-01-03

    An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.

  20. Fuel-Air Mixing and Combustion in Scramjets

    NASA Technical Reports Server (NTRS)

    Drummond, J. P.; Diskin, Glenn S.; Cutler, A. D.

    2002-01-01

    Activities in the area of scramjet fuel-air mixing and combustion associated with the Research and Technology Organization Working Group on Technologies for Propelled Hypersonic Flight are described. Work discussed in this paper has centered on the design of two basic experiments for studying the mixing and combustion of fuel and air in a scramjet. Simulations were conducted to aid in the design of these experiments. The experimental models were then constructed, and data were collected in the laboratory. Comparison of the data from a coaxial jet mixing experiment and a supersonic combustor experiment with a combustor code were then made and described. This work was conducted by NATO to validate combustion codes currently employed in scramjet design and to aid in the development of improved turbulence and combustion models employed by the codes.

  1. High-pressure combustion of binary fuel sprays

    NASA Technical Reports Server (NTRS)

    Mikami, Masato; Kono, Michikata; Sato, Jun'ichi; Dietrich, Daniel L.; Williams, Forman A.

    1995-01-01

    The ultimate objective of this study is to obtain fundamental information relevant to combustion processes that occur in fuel sprays of practical interest at high pressures in internal combustion engines. Since practical fuels are multicomponent and derived from petroleum, the present work involves the model alkane mixture of n-heptane and n-hexadecane. Since burning droplets in sprays can interact with each other, the present work involves investigation of the effects of this interaction on flame shapes and droplet burning times. The small droplets in practical combustion chambers are not significantly influenced by buoyancy. Since such small droplets are difficult to study experimentally, the present work takes advantage of microgravity to lessen buoyancy and enable information about droplet interactions to be obtained by studying larger droplets. The results are intended to provide fundamental understanding that can be used in improving descriptions of practical spray combustion.

  2. Brown clouds over South Asia: biomass or fossil fuel combustion?

    PubMed

    Gustafsson, Orjan; Krus, Martin; Zencak, Zdenek; Sheesley, Rebecca J; Granat, Lennart; Engstrm, Erik; Praveen, P S; Rao, P S P; Leck, Caroline; Rodhe, Henning

    2009-01-23

    Carbonaceous aerosols cause strong atmospheric heating and large surface cooling that is as important to South Asian climate forcing as greenhouse gases, yet the aerosol sources are poorly understood. Emission inventory models suggest that biofuel burning accounts for 50 to 90% of emissions, whereas the elemental composition of ambient aerosols points to fossil fuel combustion. We used radiocarbon measurements of winter monsoon aerosols from western India and the Indian Ocean to determine that biomass combustion produced two-thirds of the bulk carbonaceous aerosols, as well as one-half and two-thirds of two black carbon subfractions, respectively. These constraints show that both biomass combustion (such as residential cooking and agricultural burning) and fossil fuel combustion should be targeted to mitigate climate effects and improve air quality. PMID:19164746

  3. Surrogate Model Development for Fuels for Advanced Combustion Engines

    SciTech Connect

    Anand, Krishnasamy; Ra, youngchul; Reitz, Rolf; Bunting, Bruce G

    2011-01-01

    The fuels used in internal-combustion engines are complex mixtures of a multitude of different types of hydrocarbon species. Attempting numerical simulations of combustion of real fuels with all of the hydrocarbon species included is highly unrealistic. Thus, a surrogate model approach is generally adopted, which involves choosing a few representative hydrocarbon species whose overall behavior mimics the characteristics of the target fuel. The present study proposes surrogate models for the nine fuels for advanced combustion engines (FACE) that have been developed for studying low-emission, high-efficiency advanced diesel engine concepts. The surrogate compositions for the fuels are arrived at by simulating their distillation profiles to within a maximum absolute error of 4% using a discrete multi-component (DMC) fuel model that has been incorporated in the multi-dimensional computational fluid dynamics (CFD) code, KIVA-ERC-CHEMKIN. The simulated surrogate compositions cover the range and measured concentrations of the various hydrocarbon classes present in the fuels. The fidelity of the surrogate fuel models is judged on the basis of matching their specific gravity, lower heating value, hydrogen/carbon (H/C) ratio, cetane number, and cetane index with the measured data for all nine FACE fuels.

  4. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 8, January--March 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-07-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the third quarter of 1991, the following technical progress was made: Calculated the kinetic characteristics of chars from the combustion of spherical oil agglomeration beneficiated products; continued drop tube devolatilization tests of the spherical oil agglomeration beneficiated products; continued analyses of the data and samples from the CE pilot-scale tests of nine fuels; and started writing a summary topical report to include all results on the nine fuels tested.

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

    SciTech Connect

    Kennedy, I M

    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 has been completed and is now published in the open literature. This work has been extended during the current contract period to the study of the droplet combustion of a No. 2 fuel oil. Both emulsions with water and solutions of alcohols were investigated and very useful data were generated with regard to the optimization of the disruption phenomenon in terms of additive content. In addition, some preliminary work has been done with micro-emulsions. This indicated the importance of further work to elucidate the role of surfactant loading. Theoretical work on the growth of gaseous bubbles in fuel droplets has helped to define some of the controlling parameters in the disruption phenomenon. Finally the design of a new free droplet apparatus has been completed and a novel optical diagnostic technique for droplet sizing is near completion. This program has generated information which is of general interest in the field of droplet combustion and represents a considerable advance in our understanding of fuel related combustion phenomena.

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

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

    Soot formation in droplet flames is the basic component of the particulate emission process that occurs in spray combustion. The complexity of soot formation motivates a one-dimensional transport condition which has obvious advantages in modeling. Recent models of spherically symmetric droplet combustion have made this assumption when incorporating such aspects as detailed chemistry and radiation. Interestingly, spherical symmetry does not necessarily restrict the results because it has been observed that the properties of carbon formed in flames are not strongly affected by the nature of the fuel or flaming configuration. What is affected, however, are the forces acting on the soot aggregates and where they are trapped by a balance of drag and thermophoretic forces. The distribution of these forces depends on the transport conditions of the flame. Prior studies of spherical droplet flames have examined the droplet burning history of alkanes, alcohols and aromatics. Data are typically the evolution of droplet, flame, extinction, and soot shell diameters. These data are only now just beginning to find their way into comprehensive numerical models of droplet combustion to test proposed oxidation schemes for fuels such as methanol and heptane. In the present study, we report new measurements on the burning history of unsupported nonane droplets in a convection-free environment to promote spherical symmetry. The far-field gas is atmospheric pressure air at room temperature. The evolution of droplet diameter was measured using high speed cine photography of a spark-ignited, droplet within a confined volume in a drop tower. The initial droplet diameters varied between 0.5 mm and 0.6 mm. The challenge of unsupported droplets is to form, deploy and ignite them with minimal disturbance, and then to keep them in the camera field of view. Because of the difficulty of this undertaking, more sophisticated diagnostics for studying soot than photographic were not used. Supporting the test droplet by a fiber fixes the droplet position but the fiber can perturb the burning process especially for a sooting fuel. Prior studies on heptane showed little evidence for soot formation due to g-droplets of similar size the relationship between sooting and droplet diameter. For nonane droplets we expect increased sooting due to the greater number of carbon atoms. As a sooting droplet burns and its diameter decreases, proportionally less soot should form. This reduced soot, as well as the influence of soot formed earlier in the burning process which collects in a 'shell', on heat transport to the flame offers the potential for a time-varying burning rate. Such an effect was investigated and revealed in results reported here. Speculation is offered for the cause of this effect and its possible relation to soot formation.

  7. 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.

  8. Fuel supply control apparatus for internal combustion engine

    SciTech Connect

    Kanno, Y.; Nakamoto, K.; Sumitani, J.

    1989-02-22

    This patent describes fuel supply control apparatus for an internal combustion engine comprising: an air flow sensor for detecting an air intake quantity which is sucked into the internal combustion engine to be controlled, a revolution sensor which detects the number of revolutions of the internal combustion engine, an AN detecting means for detecting synchronously with each revolution the air intake quantity per each suction of the internal combustion engine on the basis of an output of the air flow sensor and the revolution sensor, an AN computing means for damping an output of the AN detecting means, synchronously with each revolution, a control means for controlling a fuel supply to the internal combustion engine on the basis of an output of the AN computing means, an air intake incremental detecting means for detecting an incremental value of the output of the AN computing means at each damping cycle, a means for increasing fuel supply quantity to the internal combustion engine on the basis of the output of the AN computing means corrected by the incremental value of the output thereof, when the air intake incremental detecting means detects that the incremental value of the output of the AN computing means is larger than a predetermined value.

  9. Straw pellets as fuel in biomass combustion units

    SciTech Connect

    Andreasen, P.; Larsen, M.G.

    1996-12-31

    In order to estimate the suitability of straw pellets as fuel in small combustion units, the Danish Technological Institute accomplished a project including a number of combustion tests in the energy laboratory. The project was part of the effort to reduce the use of fuel oil. The aim of the project was primarily to test straw pellets in small combustion units, including the following: ash/slag conditions when burning straw pellets; emission conditions; other operational consequences; and necessary work performance when using straw pellets. Five types of straw and wood pellets made with different binders and antislag agents were tested as fuel in five different types of boilers in test firings at 50% and 100% nominal boiler output.

  10. Atomization and combustion performance of antimisting kerosene and jet fuel

    NASA Technical Reports Server (NTRS)

    Fleeter, R.; Parikh, P.; Sarohia, V.

    1983-01-01

    Combustion performance of antimisting kerosene (AMK) containing FM-9 polymer was investigated at various levels of degradation (restoration of AMK for normal use in a gas turbine engine). To establish the relationship of degradation and atomization to performance in an aircraft gas turbine combustor, sprays formed by the nozzle of a JT8-D combustor with Jet A and AMK at 1 atmosphere (atm) (14.1 lb/square in absolute) pressure and 22 C at several degradation levels were analyzed. A new spray characterization technique based on digital image analysis of high resolution, wide field spray images formed under pulsed ruby laser sheet illumination was developed. Combustion tests were performed for these fuels in a JT8-D single can combustor facility to measure combustion efficiency and the lean extinction limit. Correlation of combustion performance under simulated engine operating conditions with nozzle spray Sauter mean diameter (SMD) measured at 1 atm and 22 C were observed. Fuel spray SMD and hence the combustion efficiency are strongly influenced by fuel degradation level. Use of even the most highly degraded AMK tested (filter ratio = 1.2) resulted in an increase in fuel consumption of 0.08% to 0.20% at engine cruise conditions.

  11. Soybean and Coconut Biodiesel Fuel Effects on Combustion Characteristics in a Light-Duty Diesel Engine

    SciTech Connect

    Han, Manbae; Cho, Kukwon; Sluder, Scott; Wagner, Robert M

    2008-01-01

    This study investigated the effects of soybean- and coconut-derived biodiesel fuels on combustion characteristics in a 1.7-liter direct injection, common rail diesel engine. Five sets of fuels were studied: 2007 ultra-low sulfur diesel (ULSD), 5% and 20% volumetric blends of soybean biodiesel with ULSD (soybean B5 and B20), and 5% and 20% volumetric blends of coconut biodiesel with ULSD (coconut B5 and B20). In conventional diesel combustion mode, particulate matter (PM) and nitrogen oxides (NO/dx) emissions were similar for all fuels studied except soybean B20. Soybean B20 produced the lowest PM but the highest NO/dx emissions. Compared with conventional diesel combustion mode, high efficiency clean combustion (HECC) mode, achieved by increased EGR and combustion phasing, significantly reduced both PM and NO/dx emissions for all fuels studied at the expense of higher hydrocarbon (HC) and carbon monoxide (CO) emissions and an increase in fuel consumption (less than 4%). ULSD, soybean B5, and coconut B5 showed no difference in exhaust emissions. However, PM emissions increased slightly for soybean B20 and coconut B20. NO/dx emissions increased significantly for soybean B20, while those for coconut B20 were comparable to ULSD. Differences in the chemical and physical properties of soybean and coconut biodiesel fuels compared with ULSD, such as higher fuel-borne oxygen, greater viscosity, and higher boiling temperatures, play a key role in combustion processes and, therefore, exhaust emissions. Furthermore, the highly unsaturated ester composition in soybean biodiesel can be another factor in the increase of NO/dx emissions.

  12. 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.

  13. 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.

  14. NITROUS OXIDE EMISSIONS FROM FOSSIL FUEL COMBUSTION

    EPA Science Inventory

    The role of coal combustion as a significant global source of nitrous oxide (N2O) emissions was reexamined through on-line emission measurements from six pulverized-coal-fired utility boilers and from laboratory and pilot-scale combustors. The full-scale utility boilers yielded d...

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 16, January--March 1993

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-05-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the first quarter of 1993, the following technical progress was made: Reported results of drop tube furnace data analyses to determine devolatilization kinetics; reported the results from the re-analyzed pilot-scale ash deposits from the first nine feed coals and BCFs using a modified CCSEM technique; and prepared for upcoming tests of new BCFs being produced.

  16. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 13, April--June 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1992-09-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed analyses of the samples from the pilot-scale ash deposition tests of unweathered Upper Freeport feed coal; published two technical papers at conferences; and prepared for upcoming tests of new BCFs being produced.

  17. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 15, October--December 1992

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1993-03-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. During the third quarter of 1992, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; re-analyzed the samples from the pilot-scale ash deposition tests of the first nine feed coals and BCFs using a modified CCSEM technique; updated the topical summary report; and prepared for upcoming tests of new BCFs being produced.

  18. Effect of hydrogen storage alloy on combustion properties of ammonium perchlorate /glycidylazide polymer -based propellant

    NASA Astrophysics Data System (ADS)

    Li, G. P.; Dou, Y. M.; Chai, C. P.; Luo, Y. J.

    2015-12-01

    Hydrogen storage alloys can serve as good potential fuels for propellant design, by improving the energy and combustion properties. The influence of hydrogen storage alloy (A30) on the combustion properties of ammonium perchlorate/glycidylazide polymer (AP/GAP)-based on propellant were studied. The results showed that A30 could increase the burning rate of propellants by 29.75% and 74.78%, compared with B30 and Al. The combustion model of AP/GAP-based propellant containing different fuel was built. Firstly, A30 reduced the high decomposition temperature and promote condensed phase reaction heat of AP. Secondly, A30 deduced the burning surface temperature. Thirdly, A30 might prove the explosive heat of propellant. Therefore, A30 could greatly improve combustion properties of AP/GAP-based propellant.

  19. Combustion in a Bomb with a Fuel-Injection System

    NASA Technical Reports Server (NTRS)

    Cohn, Mildred; Spencer, Robert C

    1935-01-01

    Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air densities equivalent to 5, 10, and 15 absolute atmospheres pressure at 100 degrees C.; and air-fuel ratios of 5 to 25.

  20. 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.

  1. Atomization and combustion properties of flashing injectors

    NASA Technical Reports Server (NTRS)

    Solomon, A. S. P.; Rupprecht, S. D.; Chen, L.-D.; Faeth, G. M.

    1982-01-01

    Flashing injection involves expanding a fluid through an injector until a supersaturated state is reached, causing a portion of the fluid to flash to a vapor. This investigation considered the flow, atomization and spreading properties of flashing injectors flowing liquids containing dissolved gases (Jet A/air) as well as superheated liquids (Freon 11). The use of a two stage expansion process, separated by an expansion chamber, was found to be beneficial for good atomization properties of flashing injection - particularly for dissolved gas systems. Both locally homogeneous and separated flow models provided good predictions of injector flow properties. Conventional correlations for drop sizes from pressure atomized and airblast injectors were successfully modified, using the separated flow model to prescribe injector exit conditions, to correlate drop size measurements. Additional experimental results are provided for spray angle and combustion properties of sprays from flashing injectors.

  2. Multiple fuel supply system for an internal combustion engine

    DOEpatents

    Crothers, William T.

    1977-01-01

    A multiple fuel supply or an internal combustion engine wherein phase separation of components is deliberately induced. The resulting separation permits the use of a single fuel tank to supply components of either or both phases to the engine. Specifically, phase separation of a gasoline/methanol blend is induced by the addition of a minor amount of water sufficient to guarantee separation into an upper gasoline phase and a lower methanol/water phase. A single fuel tank holds the two-phase liquid with separate fuel pickups and separate level indicators for each phase. Either gasoline or methanol, or both, can be supplied to the engine as required by predetermined parameters. A fuel supply system for a phase-separated multiple fuel supply contained in a single fuel tank is described.

  3. Solid Surface Combustion Experiment: Thick Fuel Results

    NASA Technical Reports Server (NTRS)

    Altenkirch, Robert A.; Bhattacharjee, Subrata; West, Jeff; Tang, Lin; Sacksteder, Kurt; Delichatsios, Michael A.

    1997-01-01

    The results of experiments for spread over polymethylmethacrylate, PMMA, samples in the microgravity environment of the Space Shuttle are described. The results are coupled with modelling in an effort to describe the physics of the spread process for thick fuels in a quiescent, microgravity environment and uncover differences between thin and thick fuels. A quenching phenomenon not present for thin fuels is delineated, namely the fact that for thick fuels the possibility exists that, absent an opposing flow of sufficient strength to press the flame close enough to the fuel surface to allow the heated layer in the solid to develop, the heated layer fails to become 'fully developed.' The result is that the flame slows, which in turn causes an increase in the relative radiative loss from the flame, leading eventually to extinction. This potential inability of a thick fuel to develop a steady spread rate is not present for a thin fuel because the heated layer is the fuel thickness, which reaches a uniform temperature across the thickness relatively rapidly.

  4. 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.

  5. 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.

  6. 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.

  7. Optimization of hydrocarbon fuels combustion variable composition in thermal power plants

    NASA Astrophysics Data System (ADS)

    Saifullin, E. R.; Larionov, V. M.; Busarov, A. V.; Busarov, V. V.

    2016-01-01

    It is known that associated petroleum gas and refinery waste can be used as fuel in thermal power plants. However, random changes in the composition of such fuels cause instability of the combustion process. This article explores the burning of hydrocarbon fuel in the case of long continuous change of its specific heat of combustion. The results of analysis were used to develop a technique of optimizing the combustion process, ensuring complete combustion of the fuel and its minimum flow.

  8. 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

    The results of an investigation of the effect of operating conditions and fuel properties on emission for the two-stage combustion of fuels with significant organic nitrogen content are presented. The way in which the emissions of nitrogen oxides and carbon monoxide are affected by the decreased hydrogen content and the increased organic nitrogen content of coal-derived fuels is discussed. Limited measurements of smoke from the rich-lean combustion of simulated syncrude fuels indicate relatively high smoke emissions in spite of the very lean second-stage burning. This fact, together with the high observed carbon monoxide emissions, suggests that trade-offs will be necessary between the conditions that minimize NOx and those that control CO and smoke emissions.

  9. Fireside corrosion in oxy-fuel combustion of coal

    DOE PAGESBeta

    Holcomb, Gordon R.; Tylczak, Joseph; Meier, Gerald H.; Jung, Kee Young; Mu, Nan; Yanar, Nazik M.; Pettit, Frederick S.

    2011-08-01

    Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Crmore » alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. Furthermore, the observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices.« less

  10. Fireside corrosion in oxy-fuel combustion of coal

    SciTech Connect

    Holcomb, Gordon R.; Tylczak, Joseph; Meier, Gerald H.; Jung, Kee Young; Mu, Nan; Yanar, Nazik M.; Pettit, Frederick S.

    2011-08-01

    Oxy-fuel combustion is based on burning fossil fuels in a mixture of recirculated flue gas and oxygen, rather than in air. An optimized oxy-combustion power plant will have ultra-low emissions since the flue gas that results from oxy-fuel combustion consists almost entirely of CO2 and water vapor. Once the water vapor is condensed, it is relatively easy to sequester the CO2 so that it does not escape into the atmosphere. A variety of laboratory tests comparing air-firing to oxy-firing conditions, and tests examining specific simpler combinations of oxidants, were conducted at 650-700 C. Alloys studied included model Fe-Cr and Ni-Cr alloys, commercial ferritic steels, austenitic steels, and nickel base superalloys. Furthermore, the observed corrosion behavior shows accelerated corrosion even with sulfate additions that remain solid at the tested temperatures, encapsulation of ash components in outer iron oxide scales, and a differentiation between oxy-fuel combustion flue gas recirculation choices.

  11. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 9, April--June 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-08-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the second quarter of 1991, the following technical progress was made: completed drop tube furnace devolatilization tests of the spherical oil agglomeration beneficiated products; continued analyses of samples to determine devolatilization kinetics; continued analyses of the data and samples from the CE pilot-scale tests of nine fuels; completed writing a summary topical report including all results to date on he nine fuels tested; and presented three technical papers on the project results at the 16th International Conference on Coal & Slurry Technologies.

  12. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... for fuel gas combustion devices. 60.107a Section 60.107a Protection of Environment ENVIRONMENTAL... Commenced After May 14, 2007 § 60.107a Monitoring of emissions and operations for fuel gas combustion devices. (a) Fuel gas combustion devices subject to SO 2 or H 2 S limit. The owner or operator of a...

  13. Solution combustion synthesis of strontium aluminate, SrAl2O4, powders: single-fuel versus fuel-mixture approach.

    PubMed

    Ianoş, Robert; Istratie, Roxana; Păcurariu, Cornelia; Lazău, Radu

    2016-01-14

    The solution combustion synthesis of strontium aluminate, SrAl2O4, via the classic single-fuel approach and the modern fuel-mixture approach was investigated in relation to the synthesis conditions, powder properties and thermodynamic aspects. The single-fuel approach (urea or glycine) did not yield SrAl2O4 directly from the combustion reaction. The absence of SrAl2O4 was explained by the low amount of energy released during the combustion process, in spite of the highly negative values of the standard enthalpy of reaction and standard Gibbs free energy. In the case of single-fuel recipes, the maximum combustion temperatures measured by thermal imaging (482 °C - urea, 941 °C - glycine) were much lower than the calculated adiabatic temperatures (1864 °C - urea, 2147 °C - glycine). The fuel-mixture approach (urea and glycine) clearly represented a better option, since (α,β)-SrAl2O4 resulted directly from the combustion reaction. The maximum combustion temperature measured in the case of a urea and glycine fuel mixture was the highest one (1559 °C), which was relatively close to the calculated adiabatic temperature (1930 °C). The addition of a small amount of flux, such as H3BO3, enabled the formation of pure α-SrAl2O4 directly from the combustion reaction. PMID:26661942

  14. Combustion system for dual fuel engine

    SciTech Connect

    Schaub, F.S.; Smith, J.G.

    1990-10-30

    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 cell nozzle at one end thereof and the other end having appropriate means to connect the torch cell to a fuel supply, a second fuel injector mounted in the torch cell at a predetermined angle to an axis of the torch cell, the torch cell defining an auto-ignition chamber, the second fuel injector being in operative communication with the auto-ignition chamber by an injector nozzle passageway, the injector nozzle passageway entering the auto-ignition chamber at a predetermined angle relative to the axis, and a torch nozzle passage connecting the auto-ignition chamber with the cylinder at a predetermined angle to a top inner portion of a cylinder head.

  15. Apparatus and method for solid fuel chemical looping combustion

    DOEpatents

    Siriwardane, Ranjani V; Weber, Justin M

    2015-04-14

    The disclosure provides an apparatus and method utilizing fuel reactor comprised of a fuel section, an oxygen carrier section, and a porous divider separating the fuel section and the oxygen carrier section. The porous divider allows fluid communication between the fuel section and the oxygen carrier section while preventing the migration of solids of a particular size. Maintaining particle segregation between the oxygen carrier section and the fuel section during solid fuel gasification and combustion processes allows gases generated in either section to participate in necessary reactions while greatly mitigating issues associated with mixture of the oxygen carrier with char or ash products. The apparatus and method may be utilized with an oxygen uncoupling oxygen carrier such as CuO, Mn.sub.3O.sub.4, or Co.sub.3O.sub.4, or utilized with a CO/H.sub.2 reducing oxygen carrier such as Fe.sub.2O.sub.3.

  16. Combustion characteristics of hydrogen-carbon monoxide based gaseous fuels

    NASA Technical Reports Server (NTRS)

    White, D. J.; Kubasco, A. J.; Lecren, R. T.; Notardonato, J. J.

    1982-01-01

    The results of trials with a staged combustor designed to use coal-derived gaseous fuels and reduce the NO(x) emissions from nitrogen-bound fuels to 75 ppm and 37 ppm without bound nitrogen in 15% O2 are reported. The combustor was outfitted with primary zone regenerative cooling, wherein the air cooling the primary zone was passed into the combustor at 900 F and mixed with the fuel. The increase in the primary air inlet temperature eliminated flashback and autoignition, lowered the levels of CO, unburned hydrocarbons, and smoke, and kept combustion efficiencies to the 99% level. The combustor was also equipped with dual fuel injection to test various combinations of liquid/gas fuel mixtures. Low NO(x) emissions were produced burning both Lurgi and Winkler gases, regardless of the inlet pressure and temperature conditions. Evaluation of methanation of medium energy gases is recommended for providing a fuel with low NO(x) characteristics.

  17. Pressure Effects in Droplet Combustion of Miscible Binary Fuels

    NASA Technical Reports Server (NTRS)

    Mikami, Masato; Habara, Osamu; Kono, Michikata; Sato, Jun-Ichi; Dietrich, Daniel L.; Williams, Forman A.

    1997-01-01

    The objective of this research is to improve understanding of the combustion of binary fuel mixtures in the vicinity of the critical point. Fiber-supported droplets of mixtures of n-heptane and n-hexadecane, initially 1 mm in diameter, were burned in room-temperature air at pressures from 1 MPa to 6 MPa under free-fall microgravity conditions. For most mixtures the total burning time was observed to achieve a minimum value at pressures well above the critical pressure of either of the pure fuels. This behavior is explained in terms of critical mixing conditions of a ternary system consisting of the two fuels and nitrogen. The importance of inert-gas dissolution in the liquid fuel near the critical point is thereby re-emphasized, and nonmonotonic dependence of dissolution on initial fuel composition is demonstrated. The results provide information that can be used to estimate high-pressure burning rates of fuel mixtures.

  18. 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.

  19. Municipal solid waste combustion: Fuel testing and characterization

    SciTech Connect

    Bushnell, D.J.; Canova, J.H.; Dadkhah-Nikoo, A.

    1990-10-01

    The objective of this study is to screen and characterize potential biomass fuels from waste streams. This will be accomplished by determining the types of pollutants produced while burning selected municipal waste, i.e., commercial mixed waste paper residential (curbside) mixed waste paper, and refuse derived fuel. These materials will be fired alone and in combination with wood, equal parts by weight. The data from these experiments could be utilized to size pollution control equipment required to meet emission standards. This document provides detailed descriptions of the testing methods and evaluation procedures used in the combustion testing and characterization project. The fuel samples will be examined thoroughly from the raw form to the exhaust emissions produced during the combustion test of a densified sample.

  20. Elimination of abnormal combustion in a hydrogen-fueled engine

    SciTech Connect

    Swain, M.R.; Swain, M.N.

    1995-11-01

    This report covers the design, construction, and testing of a dedicated hydrogen-fueled engine. Both part-load and full-load data were taken under laboratory conditions. The engine design included a billet aluminum single combustion chamber cylinder-head with one intake valve, two sodium coiled exhaust valves, and two spark plugs. The cylinder-head design also included drilled cooling passages. The fuel-delivery system employed two modified Siemens electrically actuated fuel injectors, The exhaust system included two separate headers, one for each exhaust port. The piston/ring combination was designed specifically for hydrogen operation.

  1. Numerical modeling of hydrogen-fueled internal combustion engines

    SciTech Connect

    Johnson, N.L.; Amsden, A.A.; Butler, T.D.

    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.

  2. Pyrometric thermometry and sizing of fuel particles in combustion

    NASA Astrophysics Data System (ADS)

    Joutsenoja, Timo

    The relation between temperature and size of a burning fuel particle can provide important knowledge about the reactivity and the detailed combustion mechanism of different coals and other solid fuels. This thesis reports on the development of methods and instrumentation for pyrometric thermometry and sizing of fuel particles and on applications to pressurised pulverised coal combustion and fluidised bed combustion. Modifications of the two-colour pyrometric technique were developed and applied to reactors of different types and several series of measurements were performed at these facilities. The prime novelty of these modifications lies in the capability to determine the size of fuel particles along with the temperature using the same pyrometric signals. In the first application a two-colour pyrometric method for simultaneous in situ measurement of temperature and size of individual fuel particles in a pressurised entrained flow reactor has been developed. This technique can be used for the identification of measured particles through a single optical port. The particle sizing is based on the proportionality of the measured radiative flux and the cross sectional area of a particle at known temperature. A large number of experiments were made in two reactors at varying process conditions with various coal types. The effects of pressure, oxygen concentration and gas temperature on the temperature and size distributions of pulverised coals are presented. As a second application a fibre-optic probe is used for measurements in fluidised bed combustion. This method allows to determine the temperatures of the fluidised bed and individual fuel particles wherever these deviate from the bed temperature and statistical determination of the particle size distribution within the population of observed particles. The experiments at two fluidised bed reactors demonstrated that the technique is applicable to fluidised bed reactors from laboratory scale to industrial scale.

  3. Chemical Looping Combustion System-Fuel Reactor Modeling

    SciTech Connect

    Gamwo, I.K.; Jung, J.; Anderson, R.R.; Soong, Y.

    2007-04-01

    Chemical looping combustion (CLC) is a process in which an oxygen carrier is used for fuel combustion instead of air or pure oxygen as shown in the figure below. The combustion is split into air and fuel reactors where the oxidation of the oxygen carrier and the reduction of the oxidized metal occur respectively. The CLC system provides a sequestration-ready CO2 stream with no additional energy required for separation. This major advantage places combustion looping at the leading edge of a possible shift in strict control of CO2 emissions from power plants. Research in this novel technology has been focused in three distinct areas: techno-economic evaluations, integration of the system into power plant concepts, and experimental development of oxygen carrier metals such as Fe, Ni, Mn, Cu, and Ca. Our recent thorough literature review shows that multiphase fluid dynamics modeling for CLC is not available in the open literature. Here, we have modified the MFIX code to model fluid dynamic in the fuel reactor. A computer generated movie of our simulation shows bubble behavior consistent with experimental observations.

  4. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

    PubMed

    Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

    2016-05-01

    Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. PMID:26894568

  5. 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.

  6. Experimental Investigation of the Effects of Fuel Characteristics on High Efficiency Clean Combustion (HECC) in a Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon; Han, Manbae; Wagner, Robert M; Sluder, Scott

    2009-01-01

    An experimental study was performed to understand fuel property effects on low temperature combustion (LTC) processes in a light-duty diesel engine. These types of combustion modes are often collectively referred to as high efficiency clean combustion (HECC). A statistically designed set of research fuels, the Fuels for Advanced Combustion Engines (FACE), were used for this study. Engine conditions consistent with low speed cruise (1500 rpm, 2.6 bar BMEP) were chosen for investigating fuel property effects on HECC operation in a GM 1.9-L common rail diesel engine. The FACE fuel matrix includes nine combinations of fuel properties including cetane number (30 to 55), aromatic contents (20 to 45 %), and 90 % distillation temperature (270 to 340 C). HECC operation was achieved with high levels of EGR and adjusting injection parameters, e.g. higher fuel rail pressure and single injection event, which is also known as Premixed Charge Compression Ignition (PCCI) combustion. Engine performance, pollutant emissions, and details of the combustion process are discussed in this paper. Cetane number was found to significantly affect the combustion process with variations in the start of injection (SOI) timing, which revealed that the ranges of SOI timing for HECC operation and the PM emission levels were distinctively different between high cetane number (55) and low cetane number fuels (30). Low cetane number fuels showed comparable levels of regulated gas emissions with high cetane number fuels and had an advantage in PM emissions.

  7. Fuel properties of cottonseed oil

    SciTech Connect

    Karaosmanoglu, F.; Tueter, M.; Goellue, E.; Yanmaz, S.; Altintig, E.

    1999-11-01

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

  8. 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.

  9. 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.

  10. 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.

  11. Fuel injector nozzle for an internal combustion engine

    SciTech Connect

    Cavanagh, Mark S.; Urven, Jr., Roger L.; Lawrence, Keith E.

    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.

  12. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 11, October--December 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1992-03-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of beneficiated coal-based fuels (BCFs) influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, combustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors perform parts of the test work are the Massachusetts Institute of Technology Physical Science, Inc. Technology Company and the University of North Dakota Energy and Environmental Research Center. Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for full-scale tests. Approximately nine BCFs will be in dry ultra fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements. During the third quarter of 1991, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed analyses of the samples from the pilot-scale ash deposition tests of three Freeport Pittsburgh 8 fuels; conducted pilot-scale combustion and ash deposition tests of a fresh batch of Upper Freeport parent coal in the CE fireside Performance Test Facility; and completed editing of the fourth quarterly report and sent it to the publishing office.

  13. 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.

  14. Electrostatic fuel conditioning of internal combustion engines

    NASA Technical Reports Server (NTRS)

    Gold, P. I.

    1982-01-01

    Diesel engines were tested to determine if they are influenced by the presence of electrostatic and magnetic fields. Field forces were applied in a variety of configurations including pretreatment of the fuel and air, however, no affect on engine performance was observed.

  15. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 10, July--September 1991

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1991-11-01

    The Pittsburgh Energy Technology Center of the US Department of Energy has contracted with Combustion Engineering, Inc. (CE) to perform a five-year project on ``Combustion Characterization of Beneficiated Coal-Based Fuels.`` The beneficiated coals are produced by other contractors under the DOE Coal Preparation Program. Several contractor-developed advanced coal cleaning processes are run at pilot-scale cleaning facilities to produce 20-ton batches of fuels for shipment to CE`s laboratory in Windsor, Connecticut. CE then processes the products into either a coal-water fuel (CWF) or a dry microfine pulverized coa1 (DMPC) form for combustion testing. The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. During the third quarter of 1991, the following technical progress was made: Continued analyses of drop tube furnace samples to determine devolatilization kinetics; completed analyses of the samples from the pilot-scale ash deposition tests of unweathered Upper Freeport fuels; completed editing of the first three quarterly reports and sent them to the publishing office; presented the project results at the Annual Contractors` Conference.

  16. 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.

  17. 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.

  18. Combustion Of Poultry-Derived Fuel in a CFBC

    NASA Astrophysics Data System (ADS)

    Jia, Lufei; Anthony, Edward J.

    Poultry farming generates large quantities of waste. Current disposal practice is to spread the poultry wastes onto farmland as fertilizer. However, as the factory farms for poultry grow both in numbers and size, the amount of poultry wastes generated has increased significandy in recent years. In consequence, excessive application of poultry wastes on farmland is resulting in more and more contaminants entering the surface water. One of the options being considered is the use of poultry waste as power plant fuel. Since poultry-derived fuel (PDF) is biomass, its co-firing will have the added advantage of reducing greenhouse gas emissions from power generation. To evaluate the combustion characteristics of co-firing PDF with coal, combustion tests of mixtures of coal and PDF were conducted in CanmetENERGY's pilot-scale CFBC. The goal of the tests was to verify that PDF can be co-fired with coal and, more importantly, that emissions from the combustion process are not adversely affected by the presence of PDF in the fuel feed. The test results were very promising and support the view that co-firing in an existing coal-fired CFBC is an effective method of utilizing this potential fuel, both resolving a potential waste disposal problem and reducing the amount of CO2 released by the boiler.

  19. Emission performance and combustion efficiency of a conical fluidized-bed combustor firing various biomass fuels.

    PubMed

    Permchart, W; Kouprianov, V I

    2004-03-01

    This paper summarizes the results of an experimental study on combustion of three distinct biomass fuels (sawdust, rice husk and pre-dried sugar cane bagasse) in a single fluidized-bed combustor (FBC) with a conical bed using silica sand as the inert bed material. Temperature, CO, NO and O2 concentrations along the combustor height as well as in flue (stack) gas were measured in the experimental tests. The effects of fuel properties and operating conditions (load and excess air) on these variables were investigated. Both CO and NO axial profiles were found to have a maximum whose location divides conventionally the combustor volume into formation (lower) and reduction (upper) regions for these pollutants. Based on CO emission and unburned carbon content in fly ash, the combustion efficiency of the conical FBC was quantified for the selected biomass fuels fired under different operating conditions. PMID:14643990

  20. Pressurized fuel carburetor for an internal combustion engine

    SciTech Connect

    Arpaia, M.A.

    1987-04-14

    A pressurized fuel carburetor is described for an internal combustion engine comprising: a main housing provided with an air intake passage equipped with a normally closed throttle valve connected to an accelerator and which intake passage is unobstructed by other movable air flow responsive means; engine manifold pressure sensing means located entirely exteriorly of the intake passage but in communication therewith downstream from the throttle valve means; a single normally fully closed fuel metering valve in communication with the air intake passage downstream from the throttle valve and mechanically connected to a source of pressurized fuel and to the accelerator and to the pressure sensing means. The means is responsive to subatmospheric pressure in the engine fuel intake manifold to open the single fuel valve and maintain a continuous flow of pressurized fuel into the air intake passage via the single fuel metering valve so long as the pressure sensing means senses subatmospheric pressure in the intake manifold. It is also responsive to a change in the intake manifold pressure to adjust the single fuel metering valve automatically to vary fuel flow into the intake passage to accommodate changing engine power output demand and to fully close the single fuel metering valve when the intake manifold pressure rises substantially to atmospheric pressure.

  1. 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.

  2. Fundamental characterization of alternate fuel effects in continuous combustion systems. Summary technical progress report, August 15, 1978-January 31, 1980

    SciTech Connect

    Blazowski, W.S.; Edelman, R.B.; Wong, E.

    1980-02-27

    The overall objective of this contract is to assist in the development of fuel-flexible combustion systems for gas turbines as well as Rankine and Stirling cycle engines. The primary emphasis of the program is on liquid hydrocarbons produced from non-petroleum resources. Fuel-flexible combustion systems will provide for more rapid transition of these alternative fuels into important future energy utilization centers (especially utility power generation with the combined cycle gas turbine). The specific technical objectives of the program are: (a) develop an improved understanding of relationships between alternative fuel properties and continuous combustion system effects, and (b) provide analytical modeling/correlation capabilities to be used as design aids for development of fuel-tolerant combustion systems. This is the second major report of the program. Key experimental findings during this reporting period concern stirred combustor soot production during operation at controlled temperature conditions, soot production as a function of combustor residence time, an improved measurement technique for total hydrocarbons and initial stirred combustor results of fuel nitrogen conversion. While the results to be presented concern a stirred combustor which utilizes premixed fuel vapor/oxidant mixtures, a new combustor which combusts liquid fuel injected into the reactor as a spray has been developed and will be described. Analytical program progress includes the development of new quasiglobal models of soot formation and assessment of needs for other submodel development.

  3. 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.

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

    NASA Astrophysics Data System (ADS)

    Hofgren, Henrik; Sundén, Bengt

    2014-09-01

    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.

  5. 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.

  6. Fuel-Air Mixing and Combustion in Scramjets. Chapter 6

    NASA Technical Reports Server (NTRS)

    Drummond, J. Philip; Diskin, Glenn S.; Cutler, Andrew D.

    2006-01-01

    At flight speeds, the residence time for atmospheric air ingested into a scramjet inlet and exiting from the engine nozzle is on the order of a millisecond. Therefore, fuel injected into the air must efficiently mix within tens of microseconds and react to release its energy in the combustor. The overall combustion process should be mixing controlled to provide a stable operating environment; in reality, however, combustion in the upstream portion of the combustor, particularly at higher Mach numbers, is kinetically controlled where ignition delay times are on the same order as the fluid scale. Both mixing and combustion time scales must be considered in a detailed study of mixing and reaction in a scramjet to understand the flow processes and to ultimately achieve a successful design. Although the geometric configuration of a scramjet is relatively simple compared to a turbomachinery design, the flow physics associated with the simultaneous injection of fuel from multiple injector configurations, and the mixing and combustion of that fuel downstream of the injectors is still quite complex. For this reason, many researchers have considered the more tractable problem of a spatially developing, primarily supersonic, chemically reacting mixing layer or jet that relaxes only the complexities introduced by engine geometry. All of the difficulties introduced by the fluid mechanics, combustion chemistry, and interactions between these phenomena can be retained in the reacting mixing layer, making it an ideal problem for the detailed study of supersonic reacting flow in a scramjet. With a good understanding of the physics of the scramjet internal flowfield, the designer can then return to the actual scramjet geometry with this knowledge and apply engineering design tools that more properly account for the complex physics. This approach will guide the discussion in the remainder of this section.

  7. Combustion of PMMA in a solid fuel ramjet

    SciTech Connect

    Korting, P.A.O.G.; Van der Geld, C.W.M.; Vos, J.B.; Wijchers, T.; Nina, M.N.R.

    1986-01-01

    The combustion behaviour of polymethyl methacrylate (PMMA) in a solid fuel ramjet was investigated using a connected pipe test facility. At pressures below 0,6 MPa almost no soot is formed, the flame is blueish and the regression rate appears to be primarily controlled by convection. At higher pressures, soot is formed and radiative heat transfer appears to be increasingly important. As a result, the regression rate becomes pressure dependant, while the effect of mass flux on regression rate decreases. Oxygen content in the air and air inlet temperature also affect combustion behaviour. No grain size effect on regression rate is noticed. Spectroscopic measurements demonstrated the presence of OH, C/sub 2/ and CH in the combustion chamber. The combustion efficiency varied between 70 and 76% and can be increased by increasing the size of the aft mixing chamber, the fuel grain length or the oxygen content in the air. Cold flow computer calculations were performed and showed good agreement with experimentally obtained results.

  8. C60 fullerenes from combustion of common fuels.

    PubMed

    Tiwari, Andrea J; Ashraf-Khorassani, Mehdi; Marr, Linsey C

    2016-03-15

    Releases of C60 fullerenes to the environment will increase with the growth of nanotechnology. Assessing the potential risks of manufactured C60 requires an understanding of how its prevalence in the environment compares to that of natural and incidental C60. This work describes the characterization of incidental C60 present in aerosols generated by combustion of five common fuels: coal, firewood, diesel, gasoline, and propane. C60 was found in exhaust generated by all five fuels; the highest concentrations in terms of mass of C60 per mass of particulate matter were associated with diesel and coal. Individual aerosols from these combustion processes were examined by transmission electron microscopy. No relationship was found between C60 content and either the separation of graphitic layers (lamellae) within the particles, nor the curvature of those lamellae. Estimated global emissions of incidental C60 to the atmosphere from coal and diesel combustion range from 1.6 to 6.3tyr(-1), depending upon combustion conditions. These emissions may be similar in magnitude to the total amount of manufactured C60 produced on an annual basis. Consequent loading of incidental C60 to the environment may be several orders of magnitude higher than has previously been modeled for manufactured C60. PMID:26789363

  9. Santilli's new fuels as sources of clean combustion

    NASA Astrophysics Data System (ADS)

    Sarma, Indrani B. Das

    2013-10-01

    Molecular combustion or nuclear fission is the conventional source of energy, which are not clean as they generate large amount of green house gas or nuclear waste. Clean energy can be obtained by harnessing renewable energy sources like solar, wind, etc. However, each of these sources has their own limitations and is dependent on geographical locations. The modern day demand of clean, cheap and abundant energy gets fulfilled by the novel fuels that have been developed through hadronic mechanics/chemistry. In the present paper, a short review on such novel fuels like Hadronic energy of non-nuclear type (combustion of MagneGas) and nuclear type (intermediate controlled nuclear fusion and particle type like stimulated neutron decay) has been presented.

  10. Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

    USGS Publications Warehouse

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

    1990-01-01

    Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

  11. A jet fuel surrogate formulated by real fuel properties

    SciTech Connect

    Dooley, Stephen; Won, Sang Hee; Chaos, Marcos; Heyne, Joshua; Ju, Yiguang; Dryer, Frederick L.; Kumar, Kamal; Sung, Chih-Jen; Wang, Haowei; Oehlschlaeger, Matthew A.; Santoro, Robert J.; Litzinger, Thomas A.

    2010-12-15

    An implicit methodology based on chemical group theory to formulate a jet aviation fuel surrogate by the measurements of several combustion related fuel properties is tested. The empirical formula and derived cetane number of an actual aviation fuel, POSF 4658, have been determined. A three component surrogate fuel for POSF 4658 has been formulated by constraining a mixture of n-decane, iso-octane and toluene to reproduce the hydrogen/carbon ratio and derived cetane number of the target fuel. The validity of the proposed surrogate is evaluated by experimental measurement of select combustion properties of POSF 4658, and the POSF 4658 surrogate. (1)A variable pressure flow reactor has been used to chart the chemical reactivity of stoichiometric mixtures of POSF 4658/O{sub 2}/N{sub 2} and POSF 4658 surrogate/O{sub 2}/N{sub 2} at 12.5 atm and 500-1000 K, fixing the carbon content at 0.3% for both mixtures. (2)The high temperature chemical reactivity and chemical kinetic-molecular diffusion coupling of POSF 4658 and POSF 4658 surrogate have been evaluated by measurement of the strained extinction limit of diffusion flames. (3)The autoignition behavior of POSF 4658 and POSF 4658 surrogate has been measured with a shock tube at 674-1222 K and with a rapid compression machine at 645-714 K for stoichiometric mixtures of fuel in air at pressures close to 20 atm. The flow reactor study shows that the character and extent of chemical reactivity of both fuels at low temperature (500-675 K) and high temperature (900 K+) are extremely similar. Slight differences in the transition from the end of the negative temperature coefficient regime to hot ignition are observed. The diffusion flame strained extinction limits of the fuels are observed to be indistinguishable when compared on a molar basis. Ignition delay measurements also show that POSF 4658 exhibits NTC behavior. Moreover, the ignition delays of both fuels are also extremely similar over the temperature range studied in both shock tube and rapid compression machine experiments. A chemical kinetic model is constructed and utilized to interpret the experimental observations and provides a rationale as to why the real fuel and surrogate fuel exhibit such similar reactivity. (author)

  12. The Review of Ignition and Combustion Processes for Water-Coal Fuels

    NASA Astrophysics Data System (ADS)

    Iegorov, R. I.; Strizhak, P. A.; Chernetskiy, M. Yu.

    2016-02-01

    In this work we have reviewed the most of known investigations of the initialization of combustion processes of water-coal fuels. The main problems of such study were emphasized. The definitive effects and factors (like mixing ratio, milling quality, the temperature of the oxidant, properties of the components and methods of the slurry preparation etc.) which have strong influence on inertia and stability of the ignition were analyzed.

  13. Thermodynamic, transport, and flow properties of gaseous products resulting from combustion of methane-air-oxygen

    NASA Technical Reports Server (NTRS)

    Klich, G. F.

    1976-01-01

    Results of calculations to determine thermodynamic, transport, and flow properties of combustion product gases are presented. The product gases are those resulting from combustion of methane-air-oxygen and methane-oxygen mixtures. The oxygen content of products resulting from the combustion of methane-air-oxygen mixtures was similiar to that of air; however, the oxygen contained in products of methane-oxygen combustion ranged from 20 percent by volume to zero for stoichiometric combustion. Calculations were made for products of reactant mixtures with fuel percentages, by mass, of 7.5 to 20. Results are presented for specific mixtures for a range of pressures varying from 0.0001 to 1,000 atm and for temperatures ranging from 200 to 3,800 K.

  14. 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.

  15. Effect of low cetane fuels on diesel engine performance 2-combustion performance of a Detroit Diesel 3-71 engine

    SciTech Connect

    Kallio, N.N.; Moyes, B.W.; Webster, G.D.; Whyte, R.B.

    1985-01-01

    Four experimental diesel fuels with cetane numbers (CN) of 40, 37, 35 and 27 have been tested in a Detroit Diesel Allison 3-71 engine. The 35 CN fuel was a blend of distillates from conventional and tar sands crude with hydrogen treated cat-cracked stock. This provided a fuel typical of the 1990's and beyond. The 27 CN fuel was the same components as the 35 CN fuel only with a larger portion of the hydrogen treated cat-cracked component. The 40 CN fuel was identical to the 35 CN fuel with a .2% DII-3 Diesel Ignition Improver. The 37 CN fuel was a blend of Canadian winter diesel fuel oil and 24% Light Cycle Oil. The fuels were tested at four load levels at each of three engine speeds. The performance and combustion characteristics were compared with the physical and chemical fuel properties.

  16. Nanocluster initiation of combustion of off-grade hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Alekseenko, S. V.; Pashchenko, S. É.; Salomatov, V. V.

    2010-09-01

    We have performed large-scale experiments on burning, in the regime of nanocluster pulsating combustion, such off-grade fuels as straw oil, hydrocarbon fuel, exhaust crankcase waste, crude oil, and others on the laboratory prototype of the self-contained burner of the Institute of Thermal Physics, Siberian Branch of the Russian Academy of Sciences. The application of modern diagnostics has made it possible to obtain a large body of information on the features of the physicochemical processes of such combustion in the presence of superheated steam. The experimental and theoretical studies have shown that as a result of the heterogeneouscatalytic decomposition of water molecules on soot nanoclusters in the mixing zone, high concentrations of the OH radical are formed and that this decomposition can be effective on carbon particles of size 1-5 nm at temperatures characteristic of traditional flares. The generation of an active OH radical leads to a significant increase in the rates of chemical reactions and a stable high-temperature combustion of "heavy" fuels with the observance of ecological norms.

  17. Simplified jet fuel reaction mechanism for lean burn combustion application

    NASA Technical Reports Server (NTRS)

    Lee, Chi-Ming; Kundu, Krishna; Ghorashi, Bahman

    1993-01-01

    Successful modeling of combustion and emissions in gas turbine engine combustors requires an adequate description of the reaction mechanism. Detailed mechanisms contain a large number of chemical species participating simultaneously in many elementary kinetic steps. Current computational fluid dynamic models must include fuel vaporization, fuel-air mixing, chemical reactions, and complicated boundary geometries. A five-step Jet-A fuel mechanism which involves pyrolysis and subsequent oxidation of paraffin and aromatic compounds is presented. This mechanism is verified by comparing with Jet-A fuel ignition delay time experimental data, and species concentrations obtained from flametube experiments. This five-step mechanism appears to be better than the current one- and two-step mechanisms.

  18. Analytical fuel property effects--small combustors

    NASA Technical Reports Server (NTRS)

    Sutton, R. D.; Troth, D. L.; Miles, G. A.

    1984-01-01

    The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

  19. Pyrolysis and oxy-fuel combustion characteristics and kinetics of petrochemical wastewater sludge using thermogravimetric analysis.

    PubMed

    Chen, Jianbiao; Mu, Lin; Cai, Jingcheng; Yao, Pikai; Song, Xigeng; Yin, Hongchao; Li, Aimin

    2015-12-01

    The pyrolysis and oxy-fuel combustion characteristics of petrochemical wastewater sludge (PS) were studied in air (O2/N2) and oxy-fuel (O2/CO2) atmospheres using non-isothermal thermogravimetric analysis (TGA). Pyrolysis experiments showed that the weight loss profiles were almost similar up to 1050K in both N2 and CO2 atmospheres, while further weight loss took place in CO2 atmosphere at higher temperatures due to char-CO2 gasification. Compared with 20%O2/80%N2, the drying and devolatilization stage of PS were delayed in 20%O2/80%CO2 due to the differences in properties of the diluting gases. In oxy-fuel combustion experiments, with O2 concentration increasing, characteristic temperatures decreased, while characteristic combustion rates and combustion performance indexes increased. Kinetic analysis of PS decomposition under various atmospheres was performed using Coats-Redfern approach. The results indicated that, with O2 concentration increasing, the activation energies of Step 1 almost kept constant, while the values of subsequent three steps increased. PMID:26386413

  20. 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.

  1. Speciated hydrocarbon emissions from the combustion of single component fuels. 1. Effect of fuel structure

    SciTech Connect

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

    1992-07-01

    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, isoctane (2,2,4-trimethylpentane), cyclohexane, 1-hexene, toluene, and methyl-t-butyl ether. Combustion of non-aromatic fuels in the PFC produced low levels of unburned fuel and high yields of methane and olefins irrespective of the molecular structure of the fuel. In contrast, hydrocarbon emissions from toluene combustion in the PFC were comprised predominantly of unburned fuel. With the PFC, low levels of 1,3-butadiene were observed from all the fuels except MTBE, for which no measurable level was detected; low levels of benzene were observed from isooctane, heptane, and 1-hexene, but significant levels from cyclohexane and toluene. No measurable amount of benzene was observed in the MTBE exhaust. For isooctane and toluene the speciated hydrocarbon emissions from a spark-ignited (SI) single-cylinder engine were also determined. HC emissions from the Si engine contained the same species as observed from the PFC, although the relative composition was different. For the non-aromatic fuel isooctane, unburned fuel represented a larger fraction of the HC emissions when run in the engine. HC emissions from toluene combustion in the engine were smaller to those from the PFC.

  2. Spray combustion of synthetic fuels. Phase II. Spray-combustion phenomena. Final report, 9 September 1981-31 December 1982

    SciTech Connect

    Not Available

    1983-05-01

    The objectives of this project were to augment existing information on physical and chemical processes relevant to synfuel combustion, to develop fundamental information and data bases applicable to synfuel utilization in industrial combustors, and to develop associated combustion models and synfuel utilization criteria with special emphasis on spray combustion. An integrated analytical and experimental program has been constructed to provide an understanding of the phenomena involved in the combustion of synthetic fuels: An extensive literature search was conducted to collect and collate available data on the thermodynamics and kinetics of pyrolysis and oxidation of synthetic fuels, related compounds, and baseline, petroleum-derived fuels. Bench-scale spray dynamics experiments were conducted to obtain data on spray combustion processes. Modular models of the combined aerodynamic and chemical processes of spray combustion were developed to represent basic spray combustor configurations. Chemical kinetics formulations were developed to model pyrolysis, soot formation and oxidation, aliphatic and aromatic hydrocarbon oxidation, and fuel-bound nitrogen conversion. These chemical kinetics formulations were based on the quasiglobal approach and were to be suitable for use in the modular spray combustion model. Models of the overall spray combustion process were used in the design of the experimental facility. The analytical models were refined and tested using the results of experiments conducted in the bench-scale spray dynamics test facility and data from other sources. The results of the modeling and experimental program were used to develop fundamental information relevant to the effective utilization of synfuels in industrial combustion systems.

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

    SciTech Connect

    Bunting, Bruce G; Bunce, Michael

    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 chemistry and particulate size measurements. Fuels obtained in late 2011, which will be evaluated in 2012, include a series of oil shale derived fuels from PNNL, green diesel fuel (hydrotreated vegetable oil) from UOP, University of Maine cellulosic biofuel (levulene), and pyrolysis derived fuels from UOP pyrolysis oil, upgraded at University of Georgia. We were able to demonstrate, through a project with University of Wisconsin, that a hybrid strategy for fuel surrogates provided both accurate and rapid CFD combustion modeling for diesel HCCI. In this strategy, high molecular weight compounds are used to more accurately represent physical processes and smaller molecular weight compounds are used for chemistry to speed chemical calculations. We conducted a small collaboration with sp3H, a French company developing an on-board fuel quality sensor based on near infrared analysis to determine how to use fuel property and chemistry information for engine control. We were able to show that selected outputs from the sensor correlated to both fuel properties and to engine performance. This collaboration leveraged our past statistical analysis work and further work will be done as opportunity permits. We conducted blending experiments to determine characteristics of ethanol blends based on the gasoline characteristics used for blending. Results indicate that much of the octane benefits gained by high level ethanol blending can be negated by use of low octane gasoline blend stocks, as allowed by ASTM D5798. This may limit ability to optimize engines for improved efficiency with ethanol fuels. Extensive data from current and previous years was leveraged into participation with several large proposal teams, as our fuels database covers a very wide range of conventional and emerging fuels and biofuels.

  4. Prediction of Agglomeration, Fouling, and Corrosion Tendency of Fuels in CFB Co-Combustion

    NASA Astrophysics Data System (ADS)

    Barišć, Vesna; Zabetta, Edgardo Coda; Sarkki, Juha

    Prediction of agglomeration, fouling, and corrosion tendency of fuels is essential to the design of any CFB boiler. During the years, tools have been successfully developed at Foster Wheeler to help with such predictions for the most commercial fuels. However, changes in fuel market and the ever-growing demand for co-combustion capabilities pose a continuous need for development. This paper presents results from recently upgraded models used at Foster Wheeler to predict agglomeration, fouling, and corrosion tendency of a variety of fuels and mixtures. The models, subject of this paper, are semi-empirical computer tools that combine the theoretical basics of agglomeration/fouling/corrosion phenomena with empirical correlations. Correlations are derived from Foster Wheeler's experience in fluidized beds, including nearly 10,000 fuel samples and over 1,000 tests in about 150 CFB units. In these models, fuels are evaluated based on their classification, their chemical and physical properties by standard analyses (proximate, ultimate, fuel ash composition, etc.;.) alongside with Foster Wheeler own characterization methods. Mixtures are then evaluated taking into account the component fuels. This paper presents the predictive capabilities of the agglomeration/fouling/corrosion probability models for selected fuels and mixtures fired in full-scale. The selected fuels include coals and different types of biomass. The models are capable to predict the behavior of most fuels and mixtures, but also offer possibilities for further improvements.

  5. Fuel-injection control system for an internal combustion engine

    SciTech Connect

    Wataya, S.; Kishimoto, Y.

    1988-04-26

    In an internal combustion engine in which air is sucked into an engine proper by way of an intake passage through a throttle valve disposed therein, and in which fuel is injected into the intake passage through fuel injection means so as to admix with the intake air to form a combustible mixture, there being a bypass conduit connecting between an upstream portion and a downstream portion of the intake passage with respect to the throttle valve for bypassing a part of the intake air across the throttle valve with a bypass valve disposed in the bypass conduit for controlling the flow of intake air passing therethrough, a fuel-injection control system is described comprising: an intake-air sensor for detecting a certain factor of the intake air sucked into the engine proper; a throttle-opening sensor adapted to generate an output signal representative of the opening degree of the throttle valve; a temperature sensor adapted to generate an output signal representative of the temperature of an engine coolant; an engine RPM sensor adapted to generate an output signal representative of the RPMs of the engine proper; and a control unit adapted to receive output signals of the sensors for controlling the operations of the fuel injection means on the basis of the information on engine operating conditions obtained from the sensors.

  6. Fuel-rich catalytic combustion: A fuel processor for high-speed propulsion

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Rollbuhler, R. James; Lezberg, Erwin A.

    1990-01-01

    Fuel-rich catalytic combustion of Jet-A fuel was studied over the equivalence ratio range 4.7 to 7.8, which yielded combustion temperatures of 1250 to 1060 K. The process was soot-free and the gaseous products were similar to those obtained in the iso-octane study. A carbon atom balance across the catalyst bed calculated for the gaseous products accounted for about 70 to 90 percent of the fuel carbon; the balance was condensed as a liquid in the cold trap. It was shown that 52 to 77 percent of the fuel carbon was C1, C2, and C3 molecules. The viability of using fuel-rich catalytic combustion as a technique for preheating a practical fuel to very high temperatures was demonstrated. Preliminary results from the scaled up version of the catalytic combustor produced a high-temperature fuel containing large amounts of hydrogen and carbon monoxide. The balance of the fuel was completely vaporized and in various stages of pyrolysis and oxidation. Visual observations indicate that there was no soot present.

  7. Fuel-rich catalytic combustion - A fuel processor for high-speed propulsion

    NASA Technical Reports Server (NTRS)

    Brabbs, Theodore A.; Rollbuhler, R. James; Lezberg, Erwin A.

    1990-01-01

    Fuel-rich catalytic combustion of Jet-A fuel was studied over the equivalence ratio range 4.7 to 7.8, which yielded combustion temperatures of 1250 to 1060 K. The process was soot-free and the gaseous products were similar to those obtained in the iso-octane study. A carbon atom balance across the catalyst bed calculated for the gaseous products accounted for about 70 to 90 percent of the fuel carbon; the balance was condensed as a liquid in the cold trap. It was shown that 52 to 77 percent of the fuel carbon was C1, C2, and C3 molecules. The viability of using fuel-rich catalytic combustion as a technique for preheating a practical fuel to very high temperatuers was demonstrated. Preliminary results from the scaled up version of the catalytic combustor produced a high-temperature fuel containing large amounts of hydrogen and carbon monoxide. The balance of the fuel was completely vaporized and in various stages of pyrolysis and oxidation. Visual observations indicate that there was no soot present.

  8. 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.

  9. Combustion characterization of beneficiated coal-based fuels. Quarterly report No. 5, May 1990--June 1990

    SciTech Connect

    Chow, O.K.; Nsakala, N.Y.

    1990-08-01

    The objectives of this project include: (1) the development of an engineering data base which will provide detailed information on the properties of BCFs influencing combustion, ash deposition, ash erosion, particulate collection, and emissions; and (2) the application of this technical data base to predict the performance and economic impacts of firing the BCFs in various commercial boiler designs. The technical approach used to develop the technical data includes: bench-scale fuel property, conbustion, and ash deposition tests; pilot-scale combustion and ash effects tests; and full-scale combustion tests. Subcontractors to CE to perform parts of the test work are the Massachusetts Institute of Technology (MIT), Physical Sciences, Inc. Technology Company (PSIT) and the University of North Dakota Energy and Environmental Research Center (UNDEERC). Twenty fuels will be characterized during the three-year base program: three feed coals, fifteen BCFs, and two conventionally cleaned coals for the full-scale tests. Approximately nine BCFs will be in dry ultra-fine coal (DUC) form, and six BCFs will be in coal-water fuel (CWF) form. Additional BCFs would be characterized during optional project supplements.

  10. 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.

  11. Radiative and combustion properties of nanoparticle-laden liquids

    NASA Astrophysics Data System (ADS)

    Tyagi, Himanshu

    Key processes in energy conversion systems are radiative transport and combustion. The general objective of this dissertation is to improve energy conversion efficiency by a fundamental investigation of how nanoparticle-laden liquid suspensions, generally termed nanofluids, can be used to either enhance radiative absorption in solar thermal energy systems, or to improve the combustion properties of liquid fuels. The present study theoretically investigates the feasibility of using a non-concentrating direct absorption solar collector (DAC) and compares its performance with that of a typical flat-plate collector. Here a nanofluid - a mixture of water and aluminum nanoparticles - is used as the absorbing medium. It was observed that the presence of nanoparticles increases the absorption of incident radiation by more than 9 times over that of pure water. Under similar operating conditions, the efficiency of a DAC using nanofluid as the working fluid is found to be up to 10 percent higher (on an absolute basis) than that of a flat-plate collector. This study also attempts to improve the ignition properties of diesel fuel by investigating the influence of adding aluminum and aluminum-oxide nanoparticles to diesel. As part of this study, droplet ignition experiments were carried out atop a heated hot plate over the range of 688 to 768 degrees centigrade. Different types of fuel mixtures were used; both particle size (15 nm and 50 nm) as well as the volume fraction (0, 0.1 and 0.5 percent) of nanoparticles added to diesel were varied. It was observed that the ignition probability for the fuel mixtures which contained nanoparticles was significantly higher than that of pure diesel. Finally, the concept of using solar energy for converting biomass into useful product-gases was explored. A molten salt mixture (containing nanoparticles) was used to absorb and transfer solar energy to the biomass. Under the highest amount of solar radiation (60 times the normal solar radiation) about 1.1 tons of biomass could be converted to useful product-gases every hour, consuming about 900 kW of sunlight at an overall efficiency of 8 percent.

  12. Supersonic cavity based combustion with kerosene/hydrogen fuel

    NASA Astrophysics Data System (ADS)

    Das, Rajarshi; Kim, Jeong Soo; Kim, Heuy Dong

    2015-04-01

    A comparative study with kerosene and hydrogen fuel in a model scramjet combustor has been carried out numerically. The effect of fuel-air equivalence ratio on the flow field properties in a cavity based mixing mechanism at a freestream Mach number of 2.08 has been probed. The investigation has been carried out in a two dimensional numerical model where a cavity of length to depth ratio of 2 is mounted on one of the walls of the flow channel. The flow field shock structure is observed to change with the change in fuel-air equivalence ratio. Total pressure loss is observed to depend both on fuel air equivalence ratio and the fuel type. The spread of fuel in the test section shows marked variation with the equivalence ratio. Performance of injector location on the fuel-air mixing is also probed during the course of the investigation.

  13. Aerodynamic properties of turbulent combustion fields

    NASA Technical Reports Server (NTRS)

    Hsiao, C. C.; Oppenheim, A. K.

    1985-01-01

    Flow fields involving turbulent flames in premixed gases under a variety of conditions are modeled by the use of a numerical technique based on the random vortex method to solve the Navier-Stokes equations and a flame propagation algorithm to trace the motion of the front and implement the Huygens principle, both due to Chorin. A successive over-relaxation hybrid method is applied to solve the Euler equation for flows in an arbitrarily shaped domain. The method of images, conformal transformation, and the integral-equation technique are also used to treat flows in special cases, according to their particular requirements. Salient features of turbulent flame propagation in premixed gases are interpreted by relating them to the aerodynamic properties of the flow field. Included among them is the well-known cellular structure of flames stabilized by bluff bodies, as well as the formation of the characteristic tulip shape of flames propagating in ducts. In its rudimentary form, the mechanism of propagation of a turbulent flame is shown to consist of: (1) rotary motion of eddies at the flame front, (2) self-advancement of the front at an appropriate normal burning speed, and (3) dynamic effects of expansion due to exothermicity of the combustion reaction. An idealized model is used to illustrate these fundamental mechanisms and to investigate basic aerodynamic features of flames in premixed gases. The case of a confined flame stabilized behind a rearward-facing step is given particular care and attention. Solutions are shown to be in satisfactory agreement with experimental results, especially with respect to global properties such as the average velocity profiles and reattachment length.

  14. 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.

  15. 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.

  16. 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.

  17. Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion

    DOEpatents

    Shen, Ming-Shing; Yang, Ralph T.

    1980-01-01

    Lime utilization for sulfurous oxides absorption in fluidized combustion of carbonaceous fuels is improved by impregnation of porous lime particulates with iron oxide. The impregnation is achieved by spraying an aqueous solution of mixed iron sulfate and sulfite on the limestone before transfer to the fluidized bed combustor, whereby the iron compounds react with the limestone substrate to form iron oxide at the limestone surface. It is found that iron oxide present in the spent limestone acts as a catalyst to regenerate the spent limestone in a reducing environment. With only small quantities of iron oxide the calcium can be recycled at a significantly increased rate.

  18. Effects of fuel and additives on combustion chamber deposits

    SciTech Connect

    Jackson, M.M.; Pocinki, S.B.

    1994-10-01

    The effects of gasoline composition, as represented in typical regular and premium unleaded gasolines and fuel additives, on Combustion Chamber Deposits (CCD) were investigated in BMW and Ford tests. In addition, the influences of engine lubricant oil and ethanol oxygenate on CCD were examined in Ford 2.3L engine dynamometer tests. Also, additive effects of packages based on mineral oil fluidizers versus synthetic fluidizers were studied in several different engines for CCD. Finally, a new method for evaluating the effect of fluidizers on valve sticking is introduced. 6 refs., 16 figs., 14 tabs.

  19. Combustion properties of Kraft Black Liquors

    SciTech Connect

    Frederick, W.J. Jr.; Hupa, M. )

    1993-04-01

    In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed. The model required certain black liquor specific combustion information which was then not currently available, and additional data were needed for evaluating the model. The overall objectives of the project reported here was to provide experimental data on key aspects of black liquor combustion, to interpret the data, and to put it into a form which would be useful for computational models for recovery boilers. The specific topics to be investigated were the volatiles and char carbon yields from pyrolysis of single black liquor droplets; a criterion for the onset of devolatilization and the accompanying rapid swelling; and the surface temperature of black liquor droplets during pyrolysis, combustion, and gasification. Additional information on the swelling characteristics of black liquor droplets was also obtained as part of the experiments conducted.

  20. 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.

  1. A perspective on the range of gasoline compression ignition combustion strategies for high engine efficiency and low NOx and soot emissions: Effects of in-cylinder fuel stratification

    DOE PAGESBeta

    Dempsey, Adam B.; Curran, Scott J.; Wagner, Robert M.

    2016-01-14

    Many research studies have shown that low temperature combustion in compression ignition engines has the ability to yield ultra-low NOx and soot emissions while maintaining high thermal efficiency. To achieve low temperature combustion, sufficient mixing time between the fuel and air in a globally dilute environment is required, thereby avoiding fuel-rich regions and reducing peak combustion temperatures, which significantly reduces soot and NOx formation, respectively. It has been demonstrated that achieving low temperature combustion with diesel fuel over a wide range of conditions is difficult because of its properties, namely, low volatility and high chemical reactivity. On the contrary, gasolinemore » has a high volatility and low chemical reactivity, meaning it is easier to achieve the amount of premixing time required prior to autoignition to achieve low temperature combustion. In order to achieve low temperature combustion while meeting other constraints, such as low pressure rise rates and maintaining control over the timing of combustion, in-cylinder fuel stratification has been widely investigated for gasoline low temperature combustion engines. The level of fuel stratification is, in reality, a continuum ranging from fully premixed (i.e. homogeneous charge of fuel and air) to heavily stratified, heterogeneous operation, such as diesel combustion. However, to illustrate the impact of fuel stratification on gasoline compression ignition, the authors have identified three representative operating strategies: partial, moderate, and heavy fuel stratification. Thus, this article provides an overview and perspective of the current research efforts to develop engine operating strategies for achieving gasoline low temperature combustion in a compression ignition engine via fuel stratification. In this paper, computational fluid dynamics modeling of the in-cylinder processes during the closed valve portion of the cycle was used to illustrate the opportunities and challenges associated with the various fuel stratification levels.« less

  2. Optical and chemical characterization of aerosols emitted from coal, heavy and light fuel oil, and small-scale wood combustion.

    PubMed

    Frey, Anna K; Saarnio, Karri; Lamberg, Heikki; Mylläri, Fanni; Karjalainen, Panu; Teinilä, Kimmo; Carbone, Samara; Tissari, Jarkko; Niemelä, Ville; Häyrinen, Anna; Rautiainen, Jani; Kytömäki, Jorma; Artaxo, Paulo; Virkkula, Aki; Pirjola, Liisa; Rönkkö, Topi; Keskinen, Jorma; Jokiniemi, Jorma; Hillamo, Risto

    2014-01-01

    Particle emissions affect radiative forcing in the atmosphere. Therefore, it is essential to know the physical and chemical characteristics of them. This work studied the chemical, physical, and optical characteristics of particle emissions from small-scale wood combustion, coal combustion of a heating and power plant, as well as heavy and light fuel oil combustion at a district heating station. Fine particle (PM1) emissions were the highest in wood combustion with a high fraction of absorbing material. The emissions were lowest from coal combustion mostly because of efficient cleaning techniques used at the power plant. The chemical composition of aerosols from coal and oil combustion included mostly ions and trace elements with a rather low fraction of absorbing material. The single scattering albedo and aerosol forcing efficiency showed that primary particles emitted from wood combustion and some cases of oil combustion would have a clear climate warming effect even over dark earth surfaces. Instead, coal combustion particle emissions had a cooling effect. Secondary processes in the atmosphere will further change the radiative properties of these emissions but are not considered in this study. PMID:24328080

  3. Oscillatory Flame Response in Acoustically Driven Fuel Droplet Combustion

    NASA Astrophysics Data System (ADS)

    Lopez, Brett; Sevilla, Cristhian; Shoji, Takeshi; Ekmekji, Ari; Smith, Owen; Karagozian, Ann

    2013-11-01

    This experimental study focuses on droplet combustion characteristics for various liquid fuels during exposure to external acoustical perturbations generated within an acoustic waveguide. The study examines combustion during excitation conditions in which the droplet is situated in the vicinity of a pressure node (PN). In response to such acoustic excitation, the flame surrounding the droplet is deflected, on average, with an orientation depending on the droplet's relative position with respect to the PN. Flame orientation is always found to be consistent with the sign of a theoretical bulk acoustic acceleration, analogous to a gravitational acceleration. Yet experimentally measured acoustic accelerations based on mean flame deflection differ quantitatively from that predicted by the theory. Phase-locked OH* chemiluminescence imaging reveals temporal oscillations in flame standoff distance from the droplet as well as chemiluminescent intensity which are especially pronounced when the droplet is situated close to the PN. Quantification of combustion-acoustic coupling via the Rayleigh index reveals a more detailed understanding of dynamical phenomena. Supported by the Air Force Research Lab/ERC Inc. and the UC CARE and MSD Scholars programs.

  4. 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.

  5. Fireside Corrosion in Oxy-fuel Combustion of Coal

    SciTech Connect

    Holcomb, Gordon R; Tylczak, Joseph; Meier, Gerald H; Lutz, Bradley; Jung, Keeyoung; Mu, Nan; Yanar, Nazik M; Pettit, Frederick S; Zhu, Jingxi; Wise, Adam; Laughlin, David E.; Sridhar, Seetharaman

    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 700ºC.

  6. Transient OH* Chemiluminescence Imaging of Acoustically Coupled Fuel Droplet Combustion

    NASA Astrophysics Data System (ADS)

    Wegener, Jeffrey; Sevilla, Cristhian; Smolke, Jennifer; Sung, Aaron; Chen, Kelvin; Smith, Owen; Karagozian, Ann

    2011-11-01

    This study focuses on combustion of liquid fuel droplets during exposure to external acoustic disturbances generated as standing waves within a closed acoustic waveguide. During such acoustic excitation, the mean flame orientation is observed to be dependent on the droplet's location relative to the pressure node (PN), and is consistent with the sign of a theoretical acoustic acceleration acting on the burning system. Yet experimentally estimated acoustic accelerations, measured from the degree of mean flame deflection, differ substantially in a quantitative sense from those predicted by theory.Phase-locked OH* chemiluminescence imaging reveals a deflected flame which oscillates in position relative to the droplet, with the largest degree of oscillation near the PN. A range of acoustic forcing frequencies and droplet locations are used to investigate flame movement over multiple acoustic cycles. The degree of flame oscillation, mean flame deflection angle, and fuel droplet burning rate all correlate with one another for different relative positions of the droplet. Supported by AFOSR.

  7. Coal-water slurry fuel internal combustion engine and method for operating same

    DOEpatents

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

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

    NASA Astrophysics Data System (ADS)

    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

    2006-02-01

    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 wood (PPW) burning produces particles with a low single scattering albedo of 0.32 and a specific mass extinction efficiency of 8.9 m2 g-1. Burning white pine needles (WPN) features a prolonged smoldering phase emitting particles that are not light-absorbing and appear much larger in size with an extinction efficiency ~5 m2 g-1. A Mie scattering model was formulated, which estimates the black carbon fraction in the PPW and WPN smoke particles at 66% and 12%, respectively. These observations may refine the current radiative forcing estimates for biomass burning emissions.

  9. Health effects of fossil-fuel combustion products: needed research

    SciTech Connect

    Not Available

    1980-01-01

    An examination is made of the research needed to expand and clarify the understanding of the products of fossil-fuel combustion, chiefly that taking place in stationary sources of power. One of the specific objectives that guided the study on which this report is based was to identify the pollutants potentially hazardous to man that are released into the environment in the course of the combustion of fossil fuels. The hazards of principal concern are those which could cause deleterious, long-term somatic and genetic effects. Another objective was to specify the nature of the research needed to determine the health effects of these pollutants on the general population. Special attention was paid to the interaction of pollutants; the meteorologic and climatic factors that affect the transport, diffusion, and transformation of pollutants; the effects of concentrations of aerosol, particulate, and thermal loads on biologic systems; and the susceptibility of some portions of the population to the effects of pollutants on the skin and cardiovascular, pulmonary, and urinary systems. Other objectives were to evaluate the methods of the proposed research, including analytic and interpretation techniques, to identify fields in which the available scientific information is inadequate for regulatory decision-making and to recommend a research program to meet those deficiencies, and to provide a logical framework within which the necessary information can be developed (the proposed program is presented in terms of subject, methods, and priorities).

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

    NASA Technical Reports Server (NTRS)

    Diskin, Glenn S.; Jachimowski, C. J.; Northam, G. Burton; Bell, Randy A.

    1987-01-01

    The combustion of H2/CH4 and H2/C2H4 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 H2/C2H4 is shown to burn much more efficiently than H2/CH4, with no pilot-off blowout equivalence ratios greater than 0.5. It is suggested that H2/hydrocarbon mixtures are feasible fuels (at least in terms of combustion efficiency) for scramjet SSTO vehicles operating at freestream Mach numbers above 4.

  11. Oscillatory Flame Response in Acoustically Coupled Fuel Droplet Combustion

    NASA Astrophysics Data System (ADS)

    Sevilla Esparza, Cristhian Israel

    This experimental study focuses on combustion of liquid fuel droplets subject to external acoustic disturbances in the form of standing waves within an acoustic waveguide. Acoustic perturbations create a mean flame deflection dependent on the droplet location relative to the pressure node (PN) or pressure antinode (PAN) in the waveguide. This flame deflection is consistent with the sign of a theoretical acoustic acceleration acting on the burning system. Yet experimentally derived acoustic accelerations estimated from the degree of flame deflection differ quantitatively from that predicted by the acoustic radiation force theory. Phase locked OH* chemiluminescence imaging reveals a deflected flame which oscillates in position relative to the stationary droplet. Flame luminosity fluctuates with pressure throughout the forcing period, indicating the flame heat release rate is influenced by acoustic excitation. The thermoacoustic instability fostered by the in-phase oscillation of pressure and heat release rate is quantified via the Rayleigh index. Evaluation of the Rayleigh index over a range of acoustic forcing frequencies and droplet locations exposes the frequency sensitive character of the combustion mechanism stemming from dissimilar acoustic and chemical kinetic time scales. The present experimental configuration provides a useful test bed for evaluating the response of different alternative and conventional fuels to an acoustically resonant environment in the context of the well-known Rayleigh criterion.

  12. 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.

  13. Applying Thermodynamics to Fossil Fuels: Heats of Combustion from Elemental Compositions.

    ERIC Educational Resources Information Center

    Lloyd, William G.; Davenport, Derek A.

    1980-01-01

    Discussed are the calculations of heats of combustions of some selected fossil fuel compounds such as some foreign shale oils and United States coals. Heating values for coal- and petroleum-derived fuel oils are also presented. (HM)

  14. Thermodynamic and transport combustion properties of hydrocarbons with air. Part 1: Properties in SI units

    NASA Technical Reports Server (NTRS)

    Gordon, S.

    1982-01-01

    Thermodynamic and transport combustion properties were calculated for a wide range of conditions for the reaction of hydrocarbons with air. Three hydrogen-carbon atom ratios (H/C = 1.7, 2.0, 2.1) were selected to represent the range of aircraft fuels. For each of these H/C ratios, combustion properties were calculated for the following conditions: Equivalence ratio: 0, 0.25, 0.5, 0.75, 1.0, 1.25 Water - dry air mass ratio: 0, 0.03 Pressure, kPa: 1.01325, 10.1325, 101.325, 1013.25, 5066.25 (or in atm: 0.01, 0.1, 1, 10, 50) Temperature, K: every 10 degrees from 200 to 900 K; every 50 degrees from 900 to 3000 K Temperature, R: every 20 degrees from 360 to 1600 R; very 100 degrees from 1600 to 5400 R. The properties presented are composition, density, molecular weight, enthalphy, entropy, specific heat at constant pressure, volume derivatives, isentropic exponent, velocity of sound, viscosity, thermal conductivity, and Prandtl number. Property tables are based on composites that were calculated by assuming both: (1) chemical equilibrium (for both homogeneous and heterogeneous phases) and (2) constant compositions for all temperatures. Properties in SI units are presented in this report for the Kelvin temperature schedules.

  15. Formation of oxides of nitrogen in monodisperse spray combustion of hydrocarbon fuels

    NASA Technical Reports Server (NTRS)

    Nizami, A. A.; Singh, S.; Cernansky, N. P.

    1982-01-01

    Experimental results of exit plane NO/NO(x) emissions from atmospheric monodisperse fuel spray combustion are presented. Six different hydrocarbon fuels were studied: isopropanol, n-propanol, n-octane, iso-octane, n-heptane and methanol. The results indicate an optimum droplet size for minimizing NO/NO(x) production for all of the test fuels. At the optimum droplet diameter, reductions in NO/NO(x) relative to the NO(x) occurred at droplet diameters of 55 and 48 microns respectively, as compared to a 50-micron droplet size for isopropanol. The occurrence of the minimum NO(x) point at different droplet diameters for the different fuels appears to be governed by the extent of prevaporization of the fuel in the spray, and is consistent with theoretical calculations based on each fuel's physical properties. Estimates are also given for the behavior of heavy fuels and of polydisperse fuel sprays in shifting the minimum NO(x) point compared to a monodisperse situation.

  16. Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor

    SciTech Connect

    Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S

    2014-03-04

    The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.

  17. Biomedically relevant chemical and physical properties of coal combustion products.

    PubMed Central

    Fisher, G L

    1983-01-01

    The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems. Because of the physicochemical complexity of the effluents, the biomedically relevant properties of these materials must be carefully assessed. Subsequent to release from combustion sources, environmental interactions further complicate assessment of the toxicity of combustion products. This report provides an overview of the biomedically relevant physical and chemical properties of coal fly ash. Coal fly ash is presented as a model complex mixture for health and safety evaluation of combustion processes. PMID:6337824

  18. Emissions of levoglucosan, methoxy phenols, and organic acids from prescribed burns, laboratory combustion of wildland fuels, and residential wood combustion.

    PubMed

    Mazzoleni, Lynn R; Zielinska, Barbara; Moosmüller, Hans

    2007-04-01

    Biomass combustion emissions make a significant contribution to the overall particulate pollution in the troposphere. Wildland or prescribed burns and residential wood combustion emissions can vary due to differences in fuel, season, time of day, and the nature of the combustion. Inadequate understanding of the relevance of these biomass combustion emissions is due to the lack of characterization of open combustion emissions and the limited understanding of the differences between these and residential wood combustion. To provide new insight to biomass combustion emissions, sampling was conducted in several types of conditions. Semi-volatile organic compounds (SVOC) were collected during four separate prescribed burns in three different ecosystems, Mariposa Sequoia Grove within Yosemite National Park, CA, desert brushes of central rural Nevada, and Toiyabye National Forest near Lake Tahoe, NV. SVOC samples were also collected under controlled conditions for several wildland fuels, including conifer needles, wildland grasses, and sagebrush. Fireplace emissions from simulated residential wood combustion were also collected and are included here for comparison. A high degree of variability was found in the emissions of organic carbon, elemental carbon, levoglucosan, methoxy phenols, and organic acids. The variability in the emissions of levoglucosan does not correlate with the PM2.5 gravimetric mass and thus may affect source apportionment estimates. PMID:17438751

  19. Combustion characteristics of a turbocharged DI compression ignition engine fueled with petroleum diesel fuels and biodiesel.

    PubMed

    Canakci, Mustafa

    2007-04-01

    In this study, the combustion characteristics and emissions of two different petroleum diesel fuels (No. 1 and No. 2) and biodiesel from soybean oil were compared. The tests were performed at steady state conditions in a four-cylinder turbocharged DI diesel engine at full load at 1400-rpm engine speed. The experimental results compared with No. 2 diesel fuel showed that biodiesel provided significant reductions in PM, CO, and unburned HC, the NO(x) increased by 11.2%. Biodiesel had a 13.8% increase in brake-specific fuel consumption due to its lower heating value. However, using No. 1 diesel fuel gave better emission results, NO(x) and brake-specific fuel consumption reduced by 16.1% and 1.2%, respectively. The values of the principal combustion characteristics of the biodiesel were obtained between two petroleum diesel fuels. The results indicated that biodiesel may be blended with No. 1 diesel fuel to be used without any modification on the engine. PMID:16822672

  20. Performance and thermal characteristics of bipropellant engines with liquid fuel film cooling and secondary combustion

    NASA Astrophysics Data System (ADS)

    Chiu, H. H.; Jiang, T. L.; Chiang, W. T.; Wang, C. J.

    1992-08-01

    The paper examines combustion enhancement by the boundary layer tripping device in liquid-fuel film-cooled bipropellant engines. The dependence of the performance gain on the geometrical factors of these devices are assessed by means of numerical simulation carried out by the bipropellant GEMCHIP Code. The principal enhancement mechanisms are the intensification of the group flame combustion and the normal combustion of the fuel droplets in the core region initiated by the inward transport of the fuel droplets by the boundary layer tripping mechanism. For an initially nonpremixed type injection of bipropellants, a dramatic gain, as high as 20-30 percent, in combustion efficiency for the fuel and oxidizer is achieved in the combustors with a tripping device. Among the three types of tripping devices used for the simulation of the combustion enhancement, those trips with triangular and rectangular cross sections offer higher gain in combustion efficiency than the semicircular-shaped device.

  1. 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...

  2. 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.

  3. Effects of Fuel Temperature on Injection Process and Combustion of Dimethyl Ether Engine.

    PubMed

    Guangxin, Gao; Zhulin, Yuan; Apeng, Zhou; Shenghua, Liu; Yanju, Wei

    2013-12-01

    To investigate the effects of fuel temperature on the injection process in the fuel-injection pipe and the combustion characteristics of compression ignition (CI) engine, tests on a four stroke, direct injection dimethyl ether (DME) engine were conducted. Experimental results show that as the fuel temperature increases from 20 to 40 °C, the sound speed is decreased by 12.2%, the peak line pressure at pump and nozzle sides are decreased by 7.2% and 5.6%, respectively. Meanwhile, the injection timing is retarded by 2.2 °CA and the injection duration is extended by 0.8 °CA. Accordingly, the ignition delay and the combustion duration are extended by 0.7 °CA and 4.0 °CA, respectively. The cylinder peak pressure is decreased by 5.4%. As a result, the effective thermal efficiency is decreased, especially for temperature above 40 °C. Before beginning an experiment, the fuel properties of DME, including the density, the bulk modulus, and the sound speed were calculated by "ThermoData." The calculated result of sound speed is consistent with the experimental results. PMID:23918238

  4. Emission of Oxygenated Polycyclic Aromatic Hydrocarbons from Indoor Solid Fuel Combustion

    PubMed Central

    Shen, Guofeng; Tao, Shu; Wang, Wei; Yang, Yifeng; Ding, Junnan; Xue, Miao; Min, Yujia; Zhu, Chen; Shen, Huizhong; Li, Wei; Wang, Bin; Wang, Rong; Wang, Wentao; Wang, Xilong; Russell, Armistead G.

    2011-01-01

    Indoor solid fuel combustion is a dominant source of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) and the latter are believed to be more toxic than the former. However, there is limited quantitative information on the emissions of OPAHs from solid fuel combustion. In this study, emission factors of OPAHs (EFOPAH) for nine commonly used crop residues and five coals burnt in typical residential stoves widely used in rural China were measured under simulated kitchen conditions. The total EFOPAH ranged from 2.80.2 to 8.12.2 mg/kg for tested crop residues and from 0.043 to 71 mg/kg for various coals and 9-fluorenone was the most abundant specie. The EFOPAH for indoor crop residue burning were 1~2 orders of magnitude higher than those from open burning, and they were affected by fuel properties and combustion conditions, like moisture and combustion efficiency. For both crop residues and coals, significantly positive correlations were found between EFs for the individual OPAHs and the parent PAHs. An oxygenation rate, Ro, was defined as the ratio of the EFs between the oxygenated and parent PAH species to describe the formation potential of OPAHs. For the studied OPAH/PAH pairs, mean Ro values were 0.16 ~ 0.89 for crop residues and 0.03 ~ 0.25 for coals. Ro for crop residues burned in the cooking stove were much higher than those for open burning and much lower than those in ambient air, indicating the influence of secondary formation of OPAH and loss of PAHs. In comparison with parent PAHs, OPAHs showed a higher tendency to be associated with particulate matter (PM), especially fine PM, and the dominate size ranges were 0.7 ~ 2.1 m for crop residues and high caking coals and < 0.7 m for the tested low caking briquettes. PMID:21375317

  5. A new comprehensive reaction mechanism for combustion of hydrocarbon fuels

    SciTech Connect

    Ranzi, E.; Sogaro, A.; Gaffuri, P.; Pennati, G.; Westbrook, C.K.; Pitz, W.J.

    1993-12-03

    A chemical kinetic model has been developed which describes pyrolysis, ignition and oxidation of many small hydrocarbon fuels over a wide range of experimental conditions. Fuels include carbon monoxide and hydrogen, methane and other alkane species up to n-butane, ethylene, propene, acetylene, and oxygenated species such as methanol, acetaldehyde and ethanol. Formation of some larger intermediate and product species including benzene, butadiene, large olefins, and cyclopentadiene has been treated in a semi-empirical manner. The reaction mechanism has been tested for conditions that do not involve transport and diffusional processes, including plug flow and stirred reactors, batch reactors and shock tubes. The present kinetic model and its validation differ from previous reaction mechanisms in two ways. First, in addition to conventional combustion data, experiments more commonly associated with chemical engineering problems such as oxidative coupling, oxidative pyrolysis and steam cracking are used to test the reaction mechanism, making it even more general than previous models. In addition, H atom abstraction and some other reaction rates, even for the smaller C{sub 2}, C{sub 3} and C{sub 4} species, are treated using approximations that facilitate future extensions to larger fuels in a convenient manner. Construction of the reaction mechanism and comparisons with experimental data illustrate the generality of the model.

  6. Combustion and heat transfer in a high speed diesel engine operating with rape seed oil methyl ester fuel

    NASA Astrophysics Data System (ADS)

    Turunen, R.

    The properties of RME (rape seed oil methyl ester) as a fuel for a diesel engine have been investigated theoretically and experimentally. The experiments were made with a turbocharged high-speed DI engine. During experiments the specific fuel consumption, exhaust gas emissions, heat release rate, flame temperature and the temperatures of the combustion chamber walls were measured. A test was also made using the measured flame temperature as an initial value for a two-zone combustion model. The theoretical investigations show that it is possible to achieve with RME approximately the same power as with ordinary diesel fuel from the same cylinder volume. The fuels give very similar theoretical (ideal) working cycles and also the efficiencies of the cycles are very near to each other.

  7. 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...

  8. 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.

  9. Effect [of] co-combustion of sewage sludge and biomass on combustion behavior and emissions in pulverized fuel systems

    SciTech Connect

    Spliethoff, H.; Hein, K.R.G.

    1999-07-01

    Biomass not only has a considerable potential as an additional fuel source but also shows a reasonable cost level in comparison to other renewable energies. The practicable fuel types are both residual material from forestry and agriculture, such as wood or straw, and especially cultivated reproducible feedstock such as Miscanthus Sinensis, whole cereal plants, poplars, or willows. Besides as single fuel, it is also considered to be sensible to utilize biomass in co-combustion in existing firing systems, such as pc-fired power stations. Biomass or sewage sludge utilized as additional fuel in coal combustion systems has consequences on combustion behavior, emissions, corrosion and residual matter. The effects of burning sewage sludge and agricultural residuals such as straw and manure as well as specially grown energy plants in combination with coal were studied in a 0.5 MW pulverized fuel test facility and a 20 kW electrically heated combustor. A major aspect of the investigations had been the required preparation and milling of the additional fuels. The investigations showed that in co-combustion of straw with coal, a grinding of 6 mm and finer is sufficient. The definitely coarser milling degree of biomass delays combustion and is observable by in-flame measurements. The investigations reveal that biomass addition has a positive effect on emissions. Since biomass in most cases contains considerably less sulphur than coal, an increasing biomass share in the thermal output makes the SO{sub 2} emissions decrease proportionally. In addition, SO{sub 2} can partly be captured in the ash by the alkaline-earth fractions of the biomass ash. As for sewage sludge, the emissions of SO{sub 2} correlate with the sulphur content of the fuel and, hence, rise with an increasing share of this biomass. Independently from the type, biomass shows a considerably stronger release of volatile matter. This latter fact may have a positive impact on NOx emissions when NOx-reducing techniques are applied. Within the framework of these investigations the following configurations were used: (1) unstaged combustion with preblending of coal and biomass, (2) air-staged combustion with preblending of coal and biomass, (3) reburning with biomass as reduction fuel, and (4) various burner configurations. The results show that the burner design and operation mode have a great influence on the NOx emissions of combined flames. Air staging and reburning are effective measures to reduce the NOx emissions of combined fuels. NOx emissions smaller than 300 mg/m at 6% O{sub 2} can be reached with all fuels.

  10. 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.

  11. Thermal effect of hydrocarbon fuels combustion after a sudden change in the specific calorific value

    NASA Astrophysics Data System (ADS)

    Saifullin, E. R.; Larionov, V. M.; Busarov, A. V.; Busarov, V. V.

    2016-01-01

    Using associated gas and waste oil refineries in thermal power plants, a complex problem due to the variability in fuel composition. This article explores the burning of hydrocarbon fuel in the case of an abrupt change in its specific combustion heat. Results of the analysis allowed developing a technique of stabilizing the rate of heat release, ensuring complete combustion of the fuel and its minimum flow.

  12. Combustion Characteristics of Oxy-fuel Burners for CO2 Capturing Boilers

    NASA Astrophysics Data System (ADS)

    Ahn, Joon; Kim, Hyouck Ju; Choi, Kyu Sung

    Oxy-fuel boilers have been developed to capture CO2 from the exhaust gas. A 50 kW class model burner has been developed and tested in a furnace type boiler. The burner has been scaled up to 0.5 and 3 MW class for fire-tube type boilers. The burners are commonly laid out in a coaxial type to effectively heat the combustion chamber of boilers. Burners are devised to support air and oxy-fuel combustion modes for the retrofitting scenario. FGR (flue gas recirculation) has been tried during the scale-up procedure. Oxy-fuel combustion yields stretched flame to uniformly heat the combustion chamber. It also provides the high CO2 concentration, which is over 90% in dry base. However, pure oxy-fuel combustion increases NO concentration, because of the reduced flow rate. The FGR can suppress the thermal NOx induced by the infiltration of the air.

  13. Combustion and emissions characteristics of a compression ignition engine fueled with n-butanol blends

    NASA Astrophysics Data System (ADS)

    Yusri, I. M.; Mamat, R.; Ali, O. M.; Aziz, A.; Akasyah, M. K.; Kamarulzaman, M. K.; Ihsan, C. K.; Mahmadul, H. M.; Rosdi, S. M.

    2015-12-01

    The use of biomass based renewable fuel, n-butanol blends for compression ignition (CI) engine has attracted wide attention due to its superior properties such as better miscibility, higher energy content, and cetane number. In this present study the use of n-butanol 10% blends (Bu10) with diesel fuel has been tested using 4-cylinder, 4-stroke common rail direct injection CI engine to investigate the combustion and emissions of the blended fuels. Based on the tested engine at BMEP=3.5Bar Bu10 fuel indicates lower first and second peak pressure by 5.4% and 2.4% for engine speed 1000rpm and 4.4% and 2.1% for engine speed 2500rpm compared to diesel fuel respectively. Percentage reduction relative to diesel fuel at engine speeds 1000rpm and 2500rpm for Bu10: Exhaust temperature was 7.5% and 5.2% respectively; Nitrogen oxides (NOx) 73.4% and 11.3% respectively.

  14. Effects of fuel cracking on combustion characteristics of a supersonic model combustor

    NASA Astrophysics Data System (ADS)

    Zhong, Zhan; Wang, Zhenguo; Sun, Mingbo

    2015-05-01

    The compositions of endothermic hydrocarbon fuels in cooling channels of regenerative cooled scramjet engines change along with fuel cracking. To investigate the effect of fuel compositions variation resulting from cracking on the combustion characteristics of supersonic combustors, a series of combustion tests with a wide range of equivalence ratios were conducted in a direct-connected test rig under the inflow conditions of Ma=3.46 and Tt=1430 K. The combustion characteristics of room temperature ethylene and vaporized China no. 3 aviation kerosene (RP-3) with negligible cracking were analyzed and compared based on the measured static pressure distributions along the combustor wall, fuel specific impulses, flame luminosity images and the one-dimensional average flow parameter distributions calculated by a quasi-one-dimensional data analysis method. The experimental results showed that the differences between the combustion characteristics of vaporized RP-3 and ethylene were sensitive to equivalence ratio. Under low equivalence ratios, vaporized RP-3 and ethylene had remarkably different combustion characteristics. Ethylene had an obvious higher static pressure level, specific impulse and combustion efficiency than vaporized RP-3 for its higher activity. The difference of combustion performance between vaporized RP-3 and ethylene was narrowed with the increase of equivalence ratio and the corresponding combustion condition improvement. When the equivalence ratio increased to 1.09, vaporized RP-3 and ethylene had tiny difference in combustion performance.

  15. Ammonia chemistry in oxy-fuel combustion of methane

    SciTech Connect

    Mendiara, Teresa; Glarborg, Peter

    2009-10-15

    The oxidation of NH{sub 3} during oxy-fuel combustion of methane, i.e., at high [CO{sub 2}], has been studied in a flow reactor. The experiments covered stoichiometries ranging from fuel rich to very fuel lean and temperatures from 973 to 1773 K. The results have been interpreted in terms of an updated detailed chemical kinetic model. A high CO{sub 2} level enhanced formation of NO under reducing conditions while it inhibited NO under stoichiometric and lean conditions. The detailed chemical kinetic model captured fairly well all the experimental trends. According to the present study, the enhanced CO concentrations and alteration in the amount and partitioning of O/H radicals, rather than direct reactions between N-radicals and CO{sub 2}, are responsible for the effect of a high CO{sub 2} concentration on ammonia conversion. When CO{sub 2} is present as a bulk gas, formation of NO is facilitated by the increased OH/H ratio. Besides, the high CO levels enhance HNCO formation through NH{sub 2}+CO. However, reactions NH{sub 2}+ O to form HNO and NH{sub 2}+H to form NH are inhibited due to the reduced concentration of O and H radicals. Instead reactions of NH{sub 2} with species from the hydrocarbon/methylamine pool preserve reactive nitrogen as reduced species. These reactions reduce the NH{sub 2} availability to form NO by other pathways like via HNO or NH and increase the probability of forming N{sub 2} instead of NO. (author)

  16. 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.

  17. 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.

  18. Advanced coal-fueled industrial cogeneration gas turbine system -- combustion development

    SciTech Connect

    LeCren, R.T.

    1994-06-01

    This topical report summarizes the combustor development work accomplished under the subject contract. The objective was to develop a combustion system for the Solar 4MW Type H Centaur gas turbine generator set which was to be used to demonstrate the economic, technical and environmental feasibility of a direct coal-fueled gas turbine in a 100 hour proof-of-concept test. This program started with a design configuration derived during the CSC program. The design went through the following evolution: CSC design which had some known shortcomings, redesigned CSC now designated as the Two Stage Slagging Combustor (TSSC), improved TSSC with the PRIS evaluated in the IBSTF, and full scale design. Supporting and complimentary activities included computer modelling, flow visualization, slag removal, SO{sub x} removal, fuel injector development and fuel properties evaluation. Three combustor rigs were utilized: the TSSC, the IBSTF and the full scale rig at Peoria. The TSSC rig, which was 1/10th scale of the proposed system, consisted of a primary and secondary zone and was used to develop the primary zone performance and to evaluate SO{sub x} and slag removal and fuel properties variations. The IBSTF rig which included all the components of the proposed system was also 1/10th scale except for the particulate removal system which was about 1/30th scale. This rig was used to verify combustor performance data obtained on the TSSC and to develop the PRIS and the particulate removal system. The full scale rig initially included the primary and secondary zones and was later modified to incorporate the PRIS. The purpose of the full scale testing was to verify the scale up calculations and to provide a combustion system for the proof-of-concept engine test that was initially planned in the program.

  19. Use of fluidic oscillator to measure fuel-air ratios of combustion gases

    NASA Technical Reports Server (NTRS)

    Riddlebaugh, S. M.

    1974-01-01

    A fluidic oscillator was investigated for use in measuring fuel-air ratios in hydrocarbon combustion processes. The oscillator was operated with dry exhaust gas from an experimental combustor burning ASTM A-1 fuel. Tests were conducted with fuel-air ratios between 0.015 and 0.031. Fuel-air ratios determined by oscillator frequency were within 0.001 of the values computed from separate flow measurements of the air and fuel.

  20. Development of Kinetic Mechanisms for Next-Generation Fuels and CFD Simulation of Advanced Combustion Engines

    SciTech Connect

    Pitz, William J.; McNenly, Matt J.; Whitesides, Russell; Mehl, Marco; Killingsworth, Nick J.; Westbrook, Charles K.

    2015-12-17

    Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.

  1. 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.

  2. Nonlinear characteristics and detection of combustion modes for a hydrocarbon fueled scramjet

    NASA Astrophysics Data System (ADS)

    Zhang, Cong; Yang, Qingchun; Chang, Juntao; Tang, Jingfeng; Bao, Wen

    2015-05-01

    An experimental investigation of combustion mode transition in a hydrocarbon fueled scramjet combustor model is reported under Mach number 2.1 and 2.5 inflow conditions. Three different combustion modes with respect to equivalence ratio are observed, namely, scramjet mode, weak ramjet mode and strong ramjet mode. The typical features of different combustion modes are analyzed by wall-pressures and one-dimensionally estimated Mach number distributions. The processes of combustion mode transitions show significant nonlinear characteristics. The static pressure and Mach number have discontinuous sudden changes as the mode transition occurs, especially near the fuel-supply region, emphasizing the importance of detection and control of combustion modes. The nonlinear characteristics of wall-pressures near the exit of the isolator can be used in the detection of different combustion modes. A series of experiments prove that this pressure-magnitude-based detection technique is feasible.

  3. 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

    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.

  4. APPLICATION OF ADVANCED TECHNOLOGY FOR NOX CONTROL: ALTERNATE FUELS AND FLUIDIZED-BED COAL COMBUSTION

    EPA Science Inventory

    The paper discusses the effect of alternate fuels and fluidized coal combustion in controlling the emission of nitrogen oxides (NOx). The current trend in energy use in the U.S. is toward greater use of coal and coal derived fuels, and on ensuring that these fuels are produced an...

  5. 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.

  6. 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

    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.

  7. Reduced Equations for Calculating the Combustion Rates of Jet-A and Methane Fuel

    NASA Technical Reports Server (NTRS)

    Molnar, Melissa; Marek, C. John

    2003-01-01

    Simplified kinetic schemes for Jet-A and methane fuels were developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) that is being developed at Glenn. These kinetic schemes presented here result in a correlation that gives the chemical kinetic time as a function of initial overall cell fuel/air ratio, pressure, and temperature. The correlations would then be used with the turbulent mixing times to determine the limiting properties and progress of the reaction. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentration of carbon monoxide as a function of fuel air ratio, pressure, and temperature. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates and the values obtained from the equilibrium correlations were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide, and NOx were obtained for both Jet-A fuel and methane.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. FINE PARTICLE EMISSIONS FROM RESIDUAL FUEL OIL COMBUSTION: CHARACTERIZATION AND MECHANISMS OF FORMATION

    EPA Science Inventory

    The paper gives results of a comparison of the characteristics of particulate matter (PM) emitted from residual fuel oil combustion in two types of combustion equipment. A small commercial 732-kW fire-tube boiler yielded a weakly bi-modal particulate size distribution (PSD) with...

  13. FINE PARTICLE EMISSIONS FROM RESIDUAL FUEL OIL COMBUSTION: CHARACTERIZATION AND MECHANISMS OF FORMATION

    EPA Science Inventory

    The paper gives results of a comparison of the characteristics of particulate matter (PM) emitted from residual fuel oil combustion in two types of combustion equipment. A small commercial 732-kW-rated fire-tube boiler yielded a weakly bimodal PM size distribution (PSD) with over...

  14. Evaluation of unthrottled combustion system options for light duty applications with future syncrude derived fuels. Alternative Fuels Utilization Program

    SciTech Connect

    Needham, J. R.; Cooper, B. M.; Norris-Jones, S. R.

    1982-12-01

    An experimental program examining the interaction between several fuel and light duty automotive engine combinations is detailed. Combustion systems addressed covered indirect and direct injection diesel and spark ignited stratified charge. Fuels primarily covered D2, naphtha and intermediate broadcut blends. Low ignition quality diesel fuels were also evaluated. The results indicate the baseline fuel tolerance of each combustion system and enable characteristics of the systems to be compared. Performance, gaseous and particulate emissions aspects were assessed. The data obtained assists in the selection of candidate combustion systems for potential future fuels. Performance and environmental penalties as appropriate are highlighted relative to the individual candidates. Areas of further work for increased understanding are also reviewed.

  15. 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.

  16. Characterization of high velocity oxy-fuel combustion sprayed hydroxyapatite.

    PubMed

    Haman, J D; Lucas, L C; Crawmer, D

    1995-02-01

    Bioceramic coatings, created by the high velocity oxy-fuel combustion spraying of hydroxyapatite (HA) powders onto commercially pure titanium, were characterized in order to determine whether this relatively new coating process can be successfully applied to bioceramic coatings of orthopaedic and dental implants. Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy were used to characterize both the HA starting powders and coatings. A 12 wk immersion test was conducted and the resulting changes in the coatings were also characterized. Calcium ion release during dissolution was measured with flame atomic absorption during the first 6 weeks of the immersion study. A comparison of powder and coating X-ray diffraction patterns and lattice parameters revealed an HA-type coating with some loss in crystallinity. Fourier transform infrared results showed a partial loss of the OH- group during spraying, however the phosphate groups were still present. Scanning electron microscopy analysis showed a lamellar structure with very close coating-to-substrate apposition. The coatings experienced a loss of calcium during the immersion study, with the greatest release in calcium occurring during the first 6 days of the study. No significant structural or chemical changes were observed during the 12 wk immersion study. These results indicate that the high velocity oxy-fuel process can produce an HA-type coating; however, the process needs further optimization, specifically in the areas of coating-to-substrate bond strength and minimization of phases present other than HA, before it would be recommended for commercial use. PMID:7749000

  17. Oscillatory Flame Response in Acoustically Driven Fuel Droplet Combustion

    NASA Astrophysics Data System (ADS)

    Sevilla, Cristhian; Edoh, Ayaboe; Wegener, Jeffrey; Sung, Aaron; Chen, Kelvin; Lopez, Brett; Smith, Owen; Karagozian, Ann

    2012-11-01

    This experimental study focuses on combustion of liquid fuel droplets during exposure to external acoustic disturbances generated as standing waves within a closed acoustic waveguide. Both visible imaging as well as phase-locked OH* chemiluminescence imaging are used to quantify flame motion and response during such excitation. Acoustic perturbations create both a mean flame deflection as well as flame front oscillations in time that can be dependent on the droplet's location relative to the pressure node (PN) or pressure antinode (PAN) in the waveguide. A range of acoustic forcing frequencies and droplet locations can be used to investigate flame movement. Phase-locked OH* chemiluminescence imaging reveals not only a deflected flame which oscillates in position relative to the droplet, but also different degrees of oscillation depending on excitation frequency and droplet position within the waveguide; there are also oscillations in localized flame front chemiluminescent intensity. Results for differences in flame dynamics are explored in the context of the well-known Rayleigh criterion, with implications for other non-premixed reactive systems. Supported by the US Air Force/ERC Inc.

  18. 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

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  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

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  20. 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

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  1. 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

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  2. 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

    ... content of the turbine's combustion fuel? 60.4360 Section 60.4360 Protection of Environment ENVIRONMENTAL... Standards of Performance for Stationary Combustion Turbines Monitoring § 60.4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of...

  3. Fuel combustion exhibiting low NO.sub.x and CO levels

    DOEpatents

    Keller, Jay O.; Bramlette, T. Tazwell; Barr, Pamela K.

    1996-01-01

    Method and apparatus for safely combusting a fuel in such manner that very low levels of NO.sub.x and CO are produced. The apparatus comprises an inlet line (12) containing a fuel and an inlet line (18) containing an oxidant. Coupled to the fuel line (12) and to the oxidant line (18) is a mixing means (11,29,33,40) for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means (11,29,33,40) is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure (8), into a combustion region (2). Coupled to the combustion region (2) is a means (1,29,33) for producing a periodic flow field within the combustion region (2) 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 (1), a rotating band (29), or a rotating cylinder (33) within an acoustic chamber (32) positioned upstream or downstream of the region (2) of combustion. The mixing means can be a one-way flapper valve (11); a rotating cylinder (33); a rotating band (29) having slots (31) that expose open ends (20,21) of said fuel inlet line (12) and said oxidant inlet line (18) simultaneously; or a set of coaxial fuel annuli (43) and oxidizer annuli (42,44). The means for producing a periodic flow field (1, 29, 33) 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 (2).

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

    SciTech Connect

    Ochs, Thomas L.; Oryshchyn, Danylo B.; Weber, Thomas .; 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.

  5. 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.

  6. Comparison of fuel value and combustion characteristics of two different RDF samples.

    PubMed

    Sever Akdağ, A; Atımtay, A; Sanin, F D

    2016-01-01

    Generation of Municipal Solid Waste (MSW) tends to increase with the growing population and economic development of the society; therefore, establishing environmentally sustainable waste management strategies is crucial. In this sense, waste to energy strategies have come into prominence since they increase the resource efficiency and replace the fossil fuels with renewable energy sources by enabling material and energy recovery instead of landfill disposal of the wastes. Refuse Derived Fuel (RDF), which is an alternative fuel produced from energy-rich Municipal Solid Waste (MSW) materials diverted from landfills, is one of the waste to energy strategies gaining more and more attention. This study aims to investigate the thermal characteristics and co-combustion efficiency of two RDF samples in Turkey. Proximate, ultimate and thermogravimetric analyses (TGA) were conducted on these samples. Furthermore, elemental compositions of ash from RDF samples were determined by X-Ray Fluorescence (XRF) analysis. The RDF samples were combusted alone and co-combusted in mixtures with coal and petroleum coke in a lab scale reactor at certain percentages on energy basis (3%, 5%, 10%, 20% and 30%) where co-combustion processes and efficiencies were investigated. It was found that the calorific values of RDF samples on dry basis were close to that of coal and a little lower compared to petroleum coke used in this study. Furthermore, the analysis indicated that when RDF in the mixture was higher than 10%, the CO concentration in the flue gas increased and so the combustion efficiency decreased; furthermore, the combustion characteristics changed from char combustion to volatile combustion. However, RDF addition to the fuel mixtures decreased the SO2 emission and did not change the NOx profiles. Also, XRF analysis showed that the slagging and fouling potential of RDF combustion was a function of RDF portion in fuel blend. When the RDF was combusted alone, the slagging and fouling indices of its ash were found to be higher than the limit values producing slagging and fouling. PMID:26360232

  7. Application of a Combustion Model to a Diesel Engine Fueled with Vegetable Oils

    NASA Astrophysics Data System (ADS)

    Radu, Rosca; Edward, Rakosi; Comsa, Iulian-Agape; Radu, Gaiginschi

    The paper presents the application of a three component model to the theoretical study of the combustion process of a Diesel engine fueled with sunflower oil and sunflower oil-Diesel fuel mixtures. The model assumes that the working fluid consists of three components: the fresh air, the flame and the burned gases. The combustion model uses the energy conservation equation: vc·Qc·dξα=dUα+dLα+dQwα, [1] where vc is the fuel cyclic dose, Qc is the fuel heating value, ξα=vcα/vc, vcα is the quantity of burned fuel up to the moment α, Uα is the internal energy of the working fluid, Qwα is the heat exchanged through the cylinder walls and Lα is the mechanical work. The heat release law was assumed to be a Vibe type one: ξα=Rc·[1-exp(-6.9·AmPp+1)]+(1-Rc)·[1-exp(-6.9·Amd+1)], [2] where: ·Ap=(α-αd)/(αP-αd) and A=(α-αd)/(αF-αd) ·αd-start of combustion angle ·αf-end of combustion angle ·αP-end of rapid combustion angle. Using Eqs. [1] and [2] we have obtained the cylinder pressure during combustion, for the vegetable fuels taken into account; the peak values were confirmed during the experiments.

  8. Advanced coal-fueled gas turbine systems: Subscale combustion testing. Topical report, Task 3.1

    SciTech Connect

    Not Available

    1993-05-01

    This is the final report on the Subscale Combustor Testing performed at Textron Defense Systems` (TDS) Haverhill Combustion Laboratories for the Advanced Coal-Fueled Gas Turbine System Program of the Westinghouse Electric Corp. This program was initiated by the Department of Energy in 1986 as an R&D effort to establish the technology base for the commercial application of direct coal-fired gas turbines. The combustion system under consideration incorporates a modular staged, rich-lean-quench, Toroidal Vortex Slogging Combustor (TVC) concept. Fuel-rich conditions in the first stage inhibit NO{sub x} formation from fuel-bound nitrogen; molten coal ash and sulfated sorbent are removed, tapped and quenched from the combustion gases by inertial separation in the second stage. Final oxidation of the fuel-rich gases, and dilution to achieve the desired turbine inlet conditions are accomplished in the third stage, which is maintained sufficiently lean so that here, too, NO{sub x} formation is inhibited. The primary objective of this work was to verify the feasibility of a direct coal-fueled combustion system for combustion turbine applications. This has been accomplished by the design, fabrication, testing and operation of a subscale development-type coal-fired combustor. Because this was a complete departure from present-day turbine combustors and fuels, it was considered necessary to make a thorough evaluation of this design, and its operation in subscale, before applying it in commercial combustion turbine power systems.

  9. 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)

  10. Biofuels combustion.

    PubMed

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly. PMID:23298249

  11. Biofuels Combustion

    NASA Astrophysics Data System (ADS)

    Westbrook, Charles K.

    2013-04-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  12. Studies on the combustion efficiency of liquid fuel rockets with variable thrust

    NASA Astrophysics Data System (ADS)

    Xiaobin, Li; Chen, Qizhi; Chen, Yunqin

    1991-12-01

    This article carries out studies on the stability characteristics of liquid fuel rocket engines within a relatively large range of variations. The research work was carried out centering around the speed and efficiency characteristics of combustion chambers. This article sets out the results of relevant experiments and theoretical calculations. From the angle of the combustion processes within combustion chambers, there were clear indications of the status of the effects of various processes (for example, evaporation or vaporization, mixing, chemical reactions, etc.) following along with changes in the operational status of variable thrust engine combustion efficiency.

  13. Ash particulate formation from pulverized coal under oxy-fuel combustion conditions.

    PubMed

    Jia, Yunlu; Lighty, JoAnn S

    2012-05-01

    Aerosol particulates are generated by coal combustion. The amount and properties of aerosol particulates, specifically size distribution and composition, can be affected by combustion conditions. Understanding the formation of these particles is important for predicting emissions and understanding potential deposition. Oxy-fuel combustion conditions utilize an oxygen-enriched gas environment with CO(2). The high concentration of CO(2) is a result of recycle flue gas which is used to maintain temperature. A hypothesis is that high CO(2) concentration reduces the vaporization of refractory oxides from combustion. A high-temperature drop-tube furnace was used under different oxygen concentrations and CO(2) versus N(2) to study the effects of furnace temperature, coal type, and gas phase conditions on particulate formation. A scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) were utilized for particle size distributions ranging from 14.3 nm to 20 μm. In addition, particles were collected on a Berner low pressure impactor (BLPI) for elemental analysis using scanning electron microscopy and energy dispersive spectroscopy. Three particle size modes were seen: ultrafine (below 0.1 μm), fine (0.1 to 1.0 μm), and coarse (above 1 μm). Ultrafine mass concentrations were directly related to estimated particle temperature, increasing with increasing temperature. For high silicon and calcium coals, Utah Skyline and PRB, there was a secondary effect due to CO(2) and the hypothesized reaction. Illinois #6, a high sulfur coal, had the highest amount of ultrafine mass and most of the sulfur was concentrated in the ultrafine and fine modes. Fine and coarse mode mass concentrations did not show a temperature or CO(2) relationship. (The table of contents graphic and abstract graphic are adapted from ref 27.). PMID:22468843

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

    DOEpatents

    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.

  16. Black and brown carbon fractal aggregates from combustion of two fuels widely used in Asian rituals

    NASA Astrophysics Data System (ADS)

    Chakrabarty, Rajan K.; Arnold, Ian J.; Francisco, Dianna M.; Hatchett, Benjamin; Hosseinpour, Farnaz; Loria, Marcela; Pokharel, Ashok; Woody, Brian M.

    2013-06-01

    Incense sticks and mustard oil are the two most popular combustion fuels during rituals and social ceremonies in Asian countries. Given their widespread use in both closed and open burning activities, it is important to quantify the spectral radiative properties of aerosols emitted from the combustion of both fuels. This information is needed by climate models to assess the impact of these aerosols on radiative forcing. In this study, we used a 3-wavelength integrated photoacoustic-nephelometer - operating simultaneously at 405, 532 and 781nm - to measure the optical coefficients of aerosols emitted from the laboratory combustion of mustard oil lamp and two types of incense sticks. From the measured optical coefficients at three wavelengths, time-varying single scattering albedo (SSA), absorption Ångström exponent (AAE), and scattering Ångström exponent (SAE) were calculated. For incense smoke particles, the time-averaged mean AAE values were found to be as high as 8.32 (between 405 and 532nm) and 6.48 (between 532 and 781nm). This spectrally-varying characteristic of AAE indicates that brown carbon - a class of organic carbon which strongly absorbs solar radiation in the blue and near ultraviolet - is the primary component of incense smoke aerosols. For aerosols emitted from the burning of mustard oil lamp, the time-averaged mean AAE values were ˜1.3 (between 405 and 781nm) indicating that black carbon (BC) is the primary constituent. Scanning electron microscopy combined with image processing revealed the morphology of incense smoke aerosols to be non-coalescing and weakly-bound aggregates with a mean two-dimensional (2-d) fractal dimension (Df)=1.9±0.07, while the mustard oil smoke aerosols had typical fractal-like BC aggregate morphology with a mean 2-d Df=1.85±0.09.

  17. Emission of oxygenated polycyclic aromatic hydrocarbons from indoor solid fuel combustion.

    PubMed

    Shen, Guofeng; Tao, Shu; Wang, Wei; Yang, Yifeng; Ding, Junnan; Xue, Miao; Min, Yujia; Zhu, Chen; Shen, Huizhong; Li, Wei; Wang, Bin; Wang, Rong; Wang, Wentao; Wang, Xilong; Russell, Armistead G

    2011-04-15

    Indoor solid fuel combustion is a dominant source of polycyclic aromatic hydrocarbons (PAHs) and oxygenated PAHs (OPAHs) and the latter are believed to be more toxic than the former. However, there is limited quantitative information on the emissions of OPAHs from solid fuel combustion. In this study, emission factors of OPAHs (EF(OPAH)) for nine commonly used crop residues and five coals burnt in typical residential stoves widely used in rural China were measured under simulated kitchen conditions. The total EF(OPAH) ranged from 2.8 ± 0.2 to 8.1 ± 2.2 mg/kg for tested crop residues and from 0.043 to 71 mg/kg for various coals and 9-fluorenone was the most abundant specie. The EF(OPAH) for indoor crop residue burning were 1-2 orders of magnitude higher than those from open burning, and they were affected by fuel properties and combustion conditions, like moisture and combustion efficiency. For both crop residues and coals, significantly positive correlations were found between EFs for the individual OPAHs and the parent PAHs. An oxygenation rate, R(o), was defined as the ratio of the EFs between the oxygenated and parent PAH species to describe the formation potential of OPAHs. For the studied OPAH/PAH pairs, mean R(o) values were 0.16-0.89 for crop residues and 0.03-0.25 for coals. R(o) for crop residues burned in the cooking stove were much higher than those for open burning and much lower than those in ambient air, indicating the influence of secondary formation of OPAH and loss of PAHs. In comparison with parent PAHs, OPAHs showed a higher tendency to be associated with particulate matter (PM), especially fine PM, and the dominate size ranges were 0.7-2.1 μm for crop residues and high caking coals and <0.7 μm for the tested low caking briquettes. PMID:21375317

  18. 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.

  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. Characterizing droplet combustion of pure and multi-component liquid fuels in a microgravity environment

    NASA Technical Reports Server (NTRS)

    Jackson, Gregory S.; Avedisian, C. Thomas

    1993-01-01

    The importance of understanding the effects of fuel composition, length scales, and other parameters on the combustion of liquid fuels has motivated the examination of simple flames which have easily characterized flow fields and hence, the potential of being modeled accurately. One such flame for liquid fuel combustion is the spherically symmetric droplet flame which can be achieved in an environment with sufficiently low gravity (i.e., low buoyancy). To examine fundamental characteristics of spherically symmetric droplet combustion, a drop tower facility has been employed to provide a microgravity environment to study droplet combustion. This paper gives a brief review of results obtained over the past three years under NASA sponsorship (grant NAG3-987).

  1. Comparative study of combustion product emissions of Pakistani coal briquettes and traditional Pakistani domestic fuels

    SciTech Connect

    Wachter, E.A.; Gammage, R.B.; Haas, J.W. III; Wilson, D.L. ); DePriest, J.C.; Wade, J. ); Ahmad, N.; Sibtain, F.; Zahid Raza, M. )

    1992-10-01

    A comparative emissions study was conducted on combustion products of various solid domestic cooking fuels; the objective was to compare relative levels of organic and inorganic toxic emissions from traditional Pakistani fuels (wood, wood charcoal, and dried animal dung) with manufactured low-rank coal briquettes (Lakhra and Sor- Range coals) under conditions simulating domestic cooking. A small combustion shed 12 m[sup 3] internal volume, air exchange rate 14 h[sup [minus]1] was used to simulate south Asian cooking rooms. 200-g charges of the various fuels were ignited in an Angethi stove located inside the shed, then combusted to completion; effluents from this combustion were monitored as a function of time. Measurements were made of respirable particulates, volatile and semi-volatile organics, CO, SO[sub 2], and NO[sub x]. Overall it appears that emissions from coal briquettes containing combustion amendments (slaked lime, clay, and potassium nitrate oxidizer) are no greater than emissions from traditional fuels, and in some cases are significantly lower; generally, emissions are highest for all fuels in the early stages of combustion.

  2. Comparative study of combustion product emissions of Pakistani coal briquettes and traditional Pakistani domestic fuels

    SciTech Connect

    Wachter, E.A.; Gammage, R.B.; Haas, J.W. III; Wilson, D.L.; DePriest, J.C.; Wade, J.; Ahmad, N.; Sibtain, F.; Zahid Raza, M.

    1992-10-01

    A comparative emissions study was conducted on combustion products of various solid domestic cooking fuels; the objective was to compare relative levels of organic and inorganic toxic emissions from traditional Pakistani fuels (wood, wood charcoal, and dried animal dung) with manufactured low-rank coal briquettes (Lakhra and Sor- Range coals) under conditions simulating domestic cooking. A small combustion shed 12 m{sup 3} internal volume, air exchange rate 14 h{sup {minus}1} was used to simulate south Asian cooking rooms. 200-g charges of the various fuels were ignited in an Angethi stove located inside the shed, then combusted to completion; effluents from this combustion were monitored as a function of time. Measurements were made of respirable particulates, volatile and semi-volatile organics, CO, SO{sub 2}, and NO{sub x}. Overall it appears that emissions from coal briquettes containing combustion amendments (slaked lime, clay, and potassium nitrate oxidizer) are no greater than emissions from traditional fuels, and in some cases are significantly lower; generally, emissions are highest for all fuels in the early stages of combustion.

  3. Pulsating combustion of gas fuel in the combustion chamber with closed resonant circuit

    NASA Astrophysics Data System (ADS)

    Yallina, E. V.; Larionov, V. M.; Iovleva, O. V.

    2013-12-01

    In the combustion chambers of the pulsation of gas flow oscillation greatly accelerate heat dissipation to the walls of the combustion chamber and improve combustion efficiency as compared with a uniform combustion mode. This allows you to effectively solve a number of problems of industrial power, including an environmentally friendly combustion products. Significant drawback of such systems - the emitted noise exceeding the permissible requirements. One solution to this problem - the separation of the resonance tube into 2 parts connected at the output to the interference of sound waves. The results of theoretical studies pulsating combustion technical mixture of propane in the system, consisting of a combustion chamber and two resonance tubes forming a closed resonant circuit. Resonators have a variable length. Calculations have shown that under certain oscillation of the resonator length to the first resonant frequency of the system is achieved by reducing SPL more than 15 dB. For oscillations at a second resonant frequency is the complete elimination of noise while maintaining intense oscillations in the combustion chamber.

  4. 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.

  5. Combustion-derived substances in deep basins of Puget Sound: historical inputs from fossil fuel and biomass combustion.

    PubMed

    Kuo, Li-Jung; Louchouarn, Patrick; Herbert, Bruce E; Brandenberger, Jill M; Wade, Terry L; Crecelius, Eric

    2011-04-01

    Reconstructions of 250 years historical inputs of two distinct types of black carbon (soot/graphitic black carbon (GBC) and char-BC) were conducted on sediment cores from two basins of the Puget Sound, WA. Signatures of polycyclic aromatic hydrocarbons (PAHs) were also used to support the historical reconstructions of BC to this system. Down-core maxima in GBC and combustion-derived PAHs occurred in the 1940s in the cores from the Puget Sound Main Basin, whereas in Hood Canal such peak was observed in the 1970s, showing basin-specific differences in inputs of combustion byproducts. This system showed relatively higher inputs from softwood combustion than the northeastern U.S. The historical variations in char-BC concentrations were consistent with shifts in climate indices, suggesting an influence of climate oscillations on wildfire events. Environmental loading of combustion byproducts thus appears as a complex function of urbanization, fuel usage, combustion technology, environmental policies, and climate conditions. PMID:21236534

  6. 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.

    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.

  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. Fine and ultrafine particles generated during fluidized bed combustion of different solid fuels

    SciTech Connect

    Urciuolo, M.; Barone, A.; D'Alessio, A.; Chirone, R.

    2008-12-15

    The paper reports an experimental study carried out with a 110-mm ID fluidized bed combustor focused on the characterization of particulates formation/emission during combustion of coal and non-fossil solid fuels. Fuels included: a bituminous coal, a commercial predried and granulated sludge (GS), a refuse-derived fuel (RDF), and a biomass waste (pine seed shells). Stationary combustion experiments were carried out analyzing the fate of fuel ashes. Fly ashes collected at the combustor exhaust were characterized both in terms of particle size distribution and chemical composition, with respect to both trace and major elements. Tapping-Mode Atomic Force Microscopy (TM-AFM) technique and high-efficiency cyclone-type collector devices were used to characterize the size and morphology of the nanometric-and micronic-size fractions of fly ash emitted at the exhaust respectively. Results showed that during the combustion process: I) the size of the nanometric fraction ranges between 2 and 65 nm; ii) depending on the fuel tested, combustion-assisted attrition or the production of the primary ash particles originally present in the fuel particles, are responsible of fine particle generation. The amount in the fly ash of inorganic compounds is larger for the waste-derived fuels, reflecting the large inherent content of these compounds in the parent fuels.

  9. Air pollution from aircraft. [jet exhaust - aircraft fuels/combustion efficiency

    NASA Technical Reports Server (NTRS)

    Heywood, J. B.; Chigier, N. A.

    1975-01-01

    A model which predicts nitric oxide and carbon monoxide emissions from a swirl can modular combustor is discussed. A detailed analysis of the turbulent fuel-air mixing process in the swirl can module wake region is reviewed. Hot wire anemometry was employed, and gas sampling analysis of fuel combustion emissions were performed.

  10. Investigation of structural and chemical transitions in copper oxide microstructures produced by combustion waves in a mixture of CuO-Cu2O-Cu and fuel

    NASA Astrophysics Data System (ADS)

    Hwang, Hayoung; Lee, Kang Yeol; Yeo, Taehan; Choi, Wonjoon

    2015-12-01

    The application of micro/nanostructured materials to combustion enables distinctive chemical reactions that can be used to modulate the reaction rates. Simultaneously, combustion is capable of changing the intrinsic properties of micro/nanostructured materials based on chemical interactions in high-temperature conditions. In this work, we investigate the structural-chemical transition of copper oxide microstructures exposed to interfacially driven combustion waves. The high thermal energy and exchange of chemical compounds resulting from the instant combustion waves cause direct transition without any further processes. The precise characterization of the structural and chemical transitions in the copper oxide microstructures and chemical fuels confirm that the self-propagating combustion waves in the layered composites of Cu/Cu2O/CuO microparticle-based films and the chemical fuel layers yield the direct synthesis of Cu(OH)2 flower-like structures and nanowires. The propagation of combustion waves at the interface induces an increase of the surface temperatures over 650 °C and the direct interaction between the copper oxide and chemical compounds of the fuel layers. Further application of these interfacially driven combustion waves will contribute to the development of one-step, fast, low-cost methods for the synthesis of micro/nanostructured materials.

  11. Increase in the rate of fuel combustion on addition of nanosized carbon particles

    NASA Astrophysics Data System (ADS)

    Shushkov, S. V.; Genarova, T. N.; Leshchevich, V. V.; Penyazkov, O. G.; Gusakova, S. V.; Egorov, A. S.; Govorov, M. I.; Prismotrov, Yu. A.

    2012-07-01

    Nanosized carbon fuel additives were formed by ultrasonic crushing of graphitized films or by subjecting ethanol to an electric discharge. The obtained specimens of fuel were tested on a setup for rapid adiabatic compression. Under conditions of ultrasonic dispersion, a wide spectrum of particle sizes was observed, and their influence on the characteristics of combustion turned out to be insignificant. When ethanol was treated by an electric discharge, spherical or plane carbon nanoclusters and various transient shapes, as well as liquid components, were synthesized. The resulting fuel displayed a substantial increase in the rate of combustion.

  12. Synthetic fuels handbook: properties, process and performance

    SciTech Connect

    Speight, J.

    2008-07-01

    The handbook is a comprehensive guide to the benefits and trade-offs of numerous alternative fuels, presenting expert analyses of the different properties, processes, and performance characteristics of each fuel. It discusses the concept systems and technology involved in the production of fuels on both industrial and individual scales. Chapters 5 and 7 are of special interest to the coal industry. Contents: Chapter 1. Fuel Sources - Conventional and Non-conventional; Chapter 2. Natural Gas; Chapter 3. Fuels From Petroleum and Heavy Oil; Chapter 4. Fuels From Tar Sand Bitumen; Chapter 5. Fuels From Coal; Chapter 6. Fuels From Oil Shale; Chapter 7. Fuels From Synthesis Gas; Chapter 8. Fuels From Biomass; Chapter 9. Fuels From Crops; Chapter 10. Fuels From Wood; Chapter 11. Fuels From Domestic and Industrial Waste; Chapter 12. Landfill Gas. 3 apps.

  13. Chemical-looping combustion -- Efficient conversion of chemical energy in fuels into work

    SciTech Connect

    Anheden, M.; Naesholm, A.S.; Svedberg, G.

    1995-12-31

    In thermal power plants, a large amount of the useful energy in the fuel is destroyed during the combustion process. This paper presents theoretical thermodynamic studies of a new system to increase the energy conversion efficiency of chemical energy in fuels into work. The system includes a gas turbine system with chemical-looping combustion where a metal oxide is used as an oxygen carrier. Instead of conventional combustion, the oxidation of the fuel is carried out in a two-step reaction. The first reaction step is an exothermic oxidation of a metal with air and the second reaction step an endothermic oxidation of the fuel with the metal oxide from the first step. The low grade heat in the exhaust gas is used to drive the endothermic reaction. This two-step reaction has proven to be one way to increase the energy utilization compared to conventional combustion. Results for a gas turbine reheat cycle with methane as a fuel and NiO as an oxygen carrier show that the gain in net power efficiency for the chemical-looping combustion system is as high as 5 percentage points compared to a similar conventional gas turbine system. An exergy analysis of the reactions shows that less irreversibilities are generated with chemical looping combustion than with conventional combustion. Another advantage with chemical-looping combustion is that the greenhouse gas CO{sub 2} is separated from the other exhaust gases without decreasing the overall-system thermal efficiency. This is an important feature since future regulations of CO{sub 2} emission are likely to be strict. Today, most of the suggested CO{sub 2} separation methods are considered to reduce the thermal efficiency at least 5--10 percentage points and to require expensive equipment.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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 μg 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

  19. Effects of Catalysts on Emissions of Pollutants from Combustion Processes of Liquid Fuels

    NASA Astrophysics Data System (ADS)

    Bok, Agnieszka; Guziałowska-Tic, Joanna; Tic, Wilhelm Jan

    2014-12-01

    The dynamic growth of the use of non-renewable fuels for energy purposes results in demand for catalysts to improve their combustion process. The paper describes catalysts used mainly in the processes of combustion of motor fuels and fuel oils. These catalysts make it possible to raise the efficiency of oxidation processes simultanously reducing the emission of pollutants. The key to success is the selection of catalyst compounds that will reduce harmful emissions of combustion products into the atmosphere. Catalysts are introduced into the combustion zone in form of solutions miscible with fuel or with air supplied to the combustion process. The following compounds soluble in fuel are inclused in the composition of the described catalysts: organometallic complexes, manganese compounds, salts originated from organic acids, ferrocen and its derivatives and sodium chloride and magnesium chloride responsible for burning the soot (chlorides). The priority is to minimize emissions of volatile organic compounds, nitrogen oxides, sulphur oxides, and carbon monoxide, as well as particulate matter.

  20. Combustion characteristics of dry coal-powder-fueled adiabatic diesel engine: Final report

    SciTech Connect

    Kakwani, R.M.; Kamo, R.

    1989-01-01

    This report describes the progress and findings of a research program aimed at investigating the combustion characteristics of dry coal powder fueled diesel engine. During this program, significant achievements were made in overcoming many problems facing the coal-powder-fueled engine. The Thermal Ignition Combustion System (TICS) concept was used to enhance the combustion of coal powder fuel. The major coal-fueled engine test results and accomplishments are as follows: design, fabrication and engine testing of improved coal feed system for fumigation of coal powder to the intake air; design, fabrication and engine testing of the TICS chamber made from a superalloy material (Hastelloy X); design, fabrication and engine testing of wear resistant chrome oxide ceramic coated piston rings and cylinder liner; lubrication system was improved to separate coal particles from the contaminated lubricating oil; control of the ignition timing of fumigated coal powder by utilizing exhaust gas recirculation (EGR) and variable TICS chamber temperature; coal-fueled engine testing was conducted in two configurations: dual fuel (with diesel pilot) and 100% coal-fueled engine without diesel pilot or heated intake air; cold starting of the 100% coal-powder-fueled engine with a glow plug; and coal-fueled-engine was operated from 800 to 1800 rpm speed and idle to full load engine conditions.

  1. Semi-volatile and particulate emissions from the combustion of alternative diesel fuels.

    PubMed

    Sidhu, S; Graham, J; Striebich, R

    2001-01-01

    Motor vehicle emissions are a major anthropogenic source of air pollution and contribute to the deterioration of urban air quality. In this paper, we report results of a laboratory investigation of particle formation from four different alternative diesel fuels, namely, compressed natural gas (CNG), dimethyl ether (DME), biodiesel, and diesel, under fuel-rich conditions in the temperature range of 800-1200 degrees C at pressures of approximately 24 atm. A single pulse shock tube was used to simulate compression ignition (CI) combustion conditions. Gaseous fuels (CNG and DME) were exposed premixed in air while liquid fuels (diesel and biodiesel) were injected using a high-pressure liquid injector. The results of surface analysis using a scanning electron microscope showed that the particles formed from combustion of all four of the above-mentioned fuels had a mean diameter less than 0.1 microm. From results of gravimetric analysis and fuel injection size it was found that under the test conditions described above the relative particulate yields from CNG, DME, biodiesel, and diesel were 0.30%. 0.026%, 0.52%, and 0.51%, respectively. Chemical analysis of particles showed that DME combustion particles had the highest soluble organic fraction (SOF) at 71%, followed by biodiesel (66%), CNG (38%) and diesel (20%). This illustrates that in case of both gaseous and liquid fuels, oxygenated fuels have a higher SOF than non-oxygenated fuels. PMID:11219694

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

    SciTech Connect

    Jung, Jonghwun; 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.

  3. Influence of fuel/oxidizer ratio on lattice parameters and morphology of combustion synthesized ZnO powders

    NASA Astrophysics Data System (ADS)

    Sharma, Suchinder K.; Pitale, Shreyas S.; Manzar Malik, M.; Dubey, R. N.; Qureshi, M. S.; Ojha, Siddharth

    2010-02-01

    We report synthesis of ZnO powders via dry combustion route. Among various parameters affecting the product formation during combustion synthesis, one is Fuel-to-oxidizer (F/O) ratio. In the present work, we have used urea as fuel and as a habit modifier. The crystallinity of ZnO is insensitive to F/O variations and fuel lean combustion procedures also leads to appropriate ZnO phase formation. Profile fitting analysis is carried out to correlate the observed and standard diffraction patterns for various samples coded SSD1 to SSD13. Williamson-Hall plot elucidates important contribution of size and strain in the diffraction pattern. Good correlation of lattice parameters is found to exist between calculated and standard values. Wealth of morphological forms (hexagonal pyramidal, spheriulitic, platelet ) and a systematic growth trend is observed. Tailored morphological and consequentially engineered physical properties can be harnessed from ZnO when urea is used. The hexagonal pyramids are anticipated to be suitable for electronic and optoelectronic devices such as field emitters, optoelectronic devices for medical diagnostics, etc. The same morphology can be easily achieved via variation in urea content through cost effective technique.

  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. Improving combustion stability in a bi-fuel engine

    SciTech Connect

    1995-06-01

    This article describes how a new strategy for ignition timing control can reduce NOx emissions from engines using CNG and gasoline. Until a proper fueling infrastructure is established, a certain fraction of vehicles powered by compressed natural gas (CNG) must have bi-fuel capability. A bi-fuel engine, enjoying the longer range of gasoline and the cleaner emissions of CNG, can overcome the problem of having few CNG fueling stations. However, bi-fuel engines must be optimized to run on both fuels since low CNG volumetric efficiency causes power losses compared to gasoline.

  6. Stability analysis of a liquid fuel annular combustion chamber. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Mcdonald, G. H.

    1978-01-01

    High frequency combustion instability problems in a liquid fuel annular combustion chamber are examined. A modified Galerkin method was used to produce a set of modal amplitude equations from the general nonlinear partial differential acoustic wave equation in order to analyze the problem of instability. 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.

  7. Manipulation of combustion waves in carbon-nanotube/fuel composites by highly reactive Mg nanoparticles.

    PubMed

    Lee, Kang Yeol; Hwang, Hayoung; Shin, Dongjoon; Choi, Wonjoon

    2015-10-28

    Manipulating the interface of micro/nanostructured materials and chemical fuels can change the fundamental characteristics of combustion waves that are generated during a reaction. In this study, we report that Mg/MgO nanoparticles actively amplify the propagation of combustion waves at the interface of multi-walled carbon nanotubes (MWCNTs) and chemical fuels. Fuel/MWCNT and fuel/MWCNT-Mg/MgO composite films were prepared by a facile synthetic method. We present complete physiochemical characterization of these composite films and evaluate the propagating velocities and real-time surface temperatures of combustion waves. Mg/MgO nanoparticles at the interface enhanced the reaction front velocity by 41%. The resulting explosive reactions supplied additional thermal energy to the chemical fuel, accelerating flame propagation. Furthermore, the surface temperatures of the composites with Mg/MgO nanoparticles were much lower, indicating how the transient heat from the reaction would ignite the unreacted fuels at lower surface temperatures despite not reaching the necessary activation energy for a chain reaction. This mechanism contributed to thermopower waves that amplified the output voltage. Furthermore, large temperature gradients due to the presence of nanoparticles increased charge transport inside the nanostructured material, due to the increased thermoelectric effects. This manipulation could contribute to the active control of interfacially driven combustion waves along nanostructured materials, yielding many potential applications. PMID:26419765

  8. 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

  9. Numerical exploration of mixing and combustion in ethylene fueled scramjet combustor

    NASA Astrophysics Data System (ADS)

    Dharavath, Malsur; Manna, P.; Chakraborty, Debasis

    2015-12-01

    Numerical simulations are performed for full scale scramjet combustor of a hypersonic airbreathing vehicle with ethylene fuel at ground test conditions corresponding to flight Mach number, altitude and stagnation enthalpy of 6.0, 30 km and 1.61 MJ/kg respectively. Three dimensional RANS equations are solved along with species transport equations and SST-kω turbulence model using Commercial CFD software CFX-11. Both nonreacting (with fuel injection) and reacting flow simulations [using a single step global reaction of ethylene-air with combined combustion model (CCM)] are carried out. The computational methodology is first validated against experimental results available in the literature and the performance parameters of full scale combustor in terms of thrust, combustion efficiency and total pressure loss are estimated from the simulation results. Parametric studies are conducted to study the effect of fuel equivalence ratio on the mixing and combustion behavior of the combustor.

  10. 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.

  11. 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; ...

  12. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    A number of important effects were 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 NO(x) formation. Unfortunately, because of differences in experimental facilities and limitations in the ranges of experimental data, a unified description of these transition region effects is not available at this time. Consequently, a fundamental experimental investigation was initiated to study the effect of droplet size, size distribution, and operating parameters on these transition region phenomena in a single well controlled spray combustion facility.

  14. Modeling of combustion processes in a solid fuel particle

    SciTech Connect

    Howard, D.W.

    1989-01-01

    During the production of granules or uranium oxide, granules of ion-exchange resin, loaded with uranium ions, are burned to remove the resin matrix and leave a uranium oxide ''ash''. Under some conditions of combustion, the oxide granules are produced in a highly fractured, porous state, while other conditions result in hard, dense, solid granules. ABAQUS was used to model the physical processes occurring during combustion: heat transfer with a very non-linear temperature dependent rate of heat generation, diffusion of reactants and products, and stress/strain resulting from the differential temperatures and from the phase changes during the combustion. The ABAQUS simulation was very successful in explaining the differences in morphology of the granules under different conditions, and in leading to control strategies to produce the desired morphology. However, some of the limitations of ABAQUS prevented obtaining as accurate a simulation as desired. 10 figs.

  15. Ideal Temperature Rise Due to Constant-pressure Combustion of a JP-4 Fuel

    NASA Technical Reports Server (NTRS)

    Huntley, S C

    1955-01-01

    The ideal temperature rise due to the constant-pressure combustion of a methylene (CH sub 2) fuel was calculated. CH sub 2 fuel closely approximates MIL-F-5624 grade JP-4 fuel presently used in most turbojet and ram-jet engines. Charts are presented from which the ideal temperature rise or the ideal quantity of fuel required to obtain a specified combustion temperature may be obtained for any flight condition likely to be encountered with turbojet or ram-jet engines using this fuel. The charts are applicable only to a fuel having a hydrogen-carbon mass ratio of 0.168. They include a range of fuel-air ratios from 0 to 1.2 fraction of stoichiometric fuel-air ratio with dissociation taken into account, inlet-air temperatures from 400 degrees to 1600 degrees R, and combustion pressures from 1/16 to 64 atmospheres. The use of the charts is illustrated by several examples.

  16. 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

  17. Effect of broad properties fuel on injector performance in a reverse flow combustor

    NASA Technical Reports Server (NTRS)

    Raddlebaugh, S. M.; Norgren, C. T.

    1983-01-01

    The effect of fuel type on the performance of various fuel injectors was investigated in a reverse flow combustor. Combustor performance and emissions are documented for simplex pressure atomizing, spill flow, and airblast fuel injectors using a broad properties fuel and compared with performance using Jet A fuel. Test conditions simulated a range of flight conditions including sea level take off, low and high altitude cruise, as well as a parametric evaluation of the effect of increased combustor loading. The baseline simplex injector produced higher emission levels with corresponding lower combustion efficiency with the broad properties fuel. There was little or not loss in performance by the two advanced concept injectors with the broad properties fuel. The airblast injector proved to be especially insensitive to fuel type.

  18. 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...

  19. 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.

    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.

  20. 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.

  1. 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. )

    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.

  2. Study of the combustion of various alternate fuels

    SciTech Connect

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

    1984-01-01

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

  3. Hydrocarbon-fuel/copper combustion chamber liner compatibility, corrosion prevention, and refurbishment

    NASA Technical Reports Server (NTRS)

    Rosenberg, S. D.; Gage, M. L.; Homer, G. D.; Franklin, J. E.

    1991-01-01

    An evaluation is made of combustion product/combustion chamber compatibility in the case of a LOX/liquid hydrocarbon booster engine based on copper-alloy thrust chamber which is regeneratively cooled by the fuel. It is found that sulfur impurities in the fuel are the primary causes of copper corrosion, through formation of Cu2S; sulfur levels as low as 1 ppm can result in sufficiently severe copper corrosion to degrade cooling channel performance. This corrosion can be completely eliminated, however, through the incorporation of an electrodeposited gold coating on the copper cooling-channel walls.

  4. Fuel droplet combustion. [ignition via shock wave shattering

    NASA Technical Reports Server (NTRS)

    Kauffman, C. W.; Wierzba, A. S.; Nicholls, J. A.

    1974-01-01

    An analytical model is developed that demonstrates the behavior of fuel drop ignition, and experimental results are presented that describe the effect of aerodynamic shattering on the process of fuel drop ignition. It is shown that the explosive ignition of a fuel drop which interacts with a shock wave in an oxidizing atmosphere depends upon the production of a fuel-oxidizer mixture in the wake of the original drop. The creation of this mixture is dependent on the formation of fine spray as a result of the aerodynamic shattering of the original fuel drop, the evaporation of the fine spray, and the mixing of the fuel vapor with the surrounding hot oxidizer. Only then does the explosive ignition occur as a result of the chemical reaction between the gaseous fuel and oxidizer.

  5. Pozzolanic properties of pulverized coal combustion bottom ash

    SciTech Connect

    Cheriaf, M.; Rocha, J.C.; Pera, J.

    1999-09-01

    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 after 28 days and especially after 90 days. The strength activity indexes measured on mortars are sufficiently important to allow the use of bottom ash in concrete. When ground for 6 h in a laboratory ball mill, the 28-day strength activity index of bottom ash is increased by 27%.

  6. 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

    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.

  7. Effect of Fuel-air Ratio Concentration in Combustion Zone on Combustion Performance of a 16-inch Ram-jet Engine

    NASA Technical Reports Server (NTRS)

    Dangle, E E; Cervenka, A J; Bahr, D W

    1953-01-01

    The results of fuel-air ratio and temperature surveys made in the flame stabilizing zone of a 16-inch ram-jet combustor indicated that the distribution of combustible mixture immediately downstream of a flame holder should be mechanically controlled if a preferred mixture composition is to be maintained in that zone. A sloping-baffle combustor configuration gave combustion efficiencies of 90 percent or greater over a range of fuel-air ratios from 0.010 to 0.045.

  8. 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.

  9. Global combustion: the connection between fossil fuel and biomass burning emissions (1997-2010).

    PubMed

    Balch, Jennifer K; Nagy, R Chelsea; Archibald, Sally; Bowman, David M J S; Moritz, Max A; Roos, Christopher I; Scott, Andrew C; Williamson, Grant J

    2016-06-01

    Humans use combustion for heating and cooking, managing lands, and, more recently, for fuelling the industrial economy. As a shift to fossil-fuel-based energy occurs, we expect that anthropogenic biomass burning in open landscapes will decline as it becomes less fundamental to energy acquisition and livelihoods. Using global data on both fossil fuel and biomass burning emissions, we tested this relationship over a 14 year period (1997-2010). The global average annual carbon emissions from biomass burning during this time were 2.2 Pg C per year (±0.3 s.d.), approximately one-third of fossil fuel emissions over the same period (7.3 Pg C, ±0.8 s.d.). There was a significant inverse relationship between average annual fossil fuel and biomass burning emissions. Fossil fuel emissions explained 8% of the variation in biomass burning emissions at a global scale, but this varied substantially by land cover. For example, fossil fuel burning explained 31% of the variation in biomass burning in woody savannas, but was a non-significant predictor for evergreen needleleaf forests. In the land covers most dominated by human use, croplands and urban areas, fossil fuel emissions were more than 30- and 500-fold greater than biomass burning emissions. This relationship suggests that combustion practices may be shifting from open landscape burning to contained combustion for industrial purposes, and highlights the need to take into account how humans appropriate combustion in global modelling of contemporary fire. Industrialized combustion is not only an important driver of atmospheric change, but also an important driver of landscape change through companion declines in human-started fires.This article is part of the themed issue 'The interaction of fire and mankind'. PMID:27216509

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

    SciTech Connect

    Karin Lundholm; Anders Nordin; Marcus Oehman; Dan Bostroem

    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.

  11. Evaluating the manufacturability and combustion behaviors of sludge-derived fuel briquettes.

    PubMed

    Chiou, Ing-Jia; Wu, I-Tsung

    2014-10-01

    Based on the physical and chemical properties as well as calorific values of pulp sludge and textile sludge, this study investigates the differences between manufacturability, relationship between extrusion pressure and formability, as well as stability and combustion behaviors of extruded sludge-derived fuel briquettes (ESBB) and cemented sludge-derived fuel blocks (CSBB). The optimum proportion and relevant usage ESBB policies are proposed as well. Experimental results indicate that a large amount of water can be saved during the ESBB manufacturing process. Additionally, energy consumption decreases during the drying process. ESBB also has a more compact structure than that of CSBB, and its mean penetration loading is approximately 18.7 times higher as well. Moreover, the flame temperature of ESBB (624-968°C) is significantly higher than that of CSBB (393-517°C). Also, the dry bulk density and moisture regain of ESBB is significantly related to the penetration loading. Furthermore, the optimum mix proportion of ESBB is co-determined by the formability of pulp sludge and the calorific values of textile sludge. While considering the specific conditions (including formability, stability and calorific values), the recommended mix proportion for ESBB is PS50TS50. PMID:24913348

  12. Deposition and material response from Mach 0.3 burner rig combustion of SRC 2 fuels

    NASA Technical Reports Server (NTRS)

    Santoro, G. J.; Kohl, F. J.; Stearns, C. A.; Fryburg, G. C.; Johnson, J. R.

    1980-01-01

    Collectors at 1173K (900 C) were exposed to the combustion products of a Mach 0.3 burner rig fueled with various industrial turbine liquid fuels from solvent refined coals. Four fuels were employed: a naphtha, a light oil, a wash solvent and a mid-heavy distillate blend. The response of four superalloys (IN-100, U 700, IN 792 and M-509) to exposure to the combustion gases from the SRC-2 naphtha and resultant deposits was also determined. The SRC-2 fuel analysis and insights obtained during the combustion experience are discussed. Particular problems encountered were fuel instability and reactions of the fuel with hardware components. The major metallic elements which contributed to the deposits were copper, iron, chromium, calcium, aluminum, nickel, silicon, titanium, zinc, and sodium. The deposits were found to be mainly metal oxides. An equilibrium thermodynamic analysis was employed to predict the chemical composition of the deposits. The agreement between the predicted and observed compounds was excellent. No hot corrosion was observed. This was expected because the deposits contained very little sodium or potassium and consisted mainly of the unreactive oxides. However, the amounts of deposits formed indicated that fouling is a potential problem with the use of these fuels.

  13. 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.

  14. Fuel-Flexible Combustion System for Refinery and Chemical Plant Process Heaters

    SciTech Connect

    2010-06-01

    Funded by the American Recovery and Reinvestment Act of 2009 ENVIRON International Corporation, in collaboration with Callidus Technologies by Honeywell and Shell Global Solutions, Inc., will develop and demonstrate a full-scale fuel blending and combustion system. This system will allow a broad range of opportunity fuel compositions, including syngas, biogas, natural gas, and refinery fuel gas, to be safely, cost-effectively, and efficiently utilized while generating minimal emissions of criteria pollutants. The project will develop a commercial technology for application in refinery and chemical plant process heaters where opportunity fuels are used.

  15. 3D computation of hydrogen-fueled combustion around turbine blade-effect of arrangement of injector holes-

    NASA Astrophysics Data System (ADS)

    Yamamoto, Makoto; Ikeda, Junichi; Inaba, Kazuaki

    2006-09-01

    Recently, a number of environmental problems caused from fossil fuel combustion have been focused on. In addition, with the eventual depletion of fossil energy resources, hydrogen gas is expected to be an alternative energy resource in the near future. It is characterized by high energy per unit weight, high reaction rate, wide range of flammability and the low emission property. On the other hand, many researches have been underway in several countries to improve a propulsion system for an advanced aircraft. The system is required to have higher power, lighter weight and lower emissions than existing ones. In such a future propulsion system, hydrogen gas would be one of the promising fuels for realizing the requirements. Considering these backgrounds, our group has proposed a new cycle concept for hydrogen-fueled aircraft propulsion system. In the present study, we perform 3 dimensional computations of turbulent flow fields with hydrogen-fueled combustion around a turbine blade. The main objective is to clarify the influence of arrangement of hydrogen injector holes. Changing the chordwise and spanwise spacings of the holes, the 3 dimensional nature of the flow and thermal fields is numerically studied.

  16. Temperatures in a fuel particle burning in a fluidized bed: The effect of drying, devolatilization, and char combustion

    SciTech Connect

    Winter, F.; Prah, M.E.; Hofbauer, H.

    1997-02-01

    Intra-particle temperatures and the emissions of carbon dioxide, carbon monoxide, and total hydrocarbons have been measured during devolatilization and char combustion of large spheres (3--20 mm diameter) of selected fuels. The fuels range from a carbon-rich, bituminous coal to two different, sub-bituminous coals of very different moisture and ash contents, to a highly volatile and ash-rich sewage sludge and to beech wood with the highest volatile content. To obtain results under various fluidized bed combustor conditions and to independently change the governing parameters, the experiments were performed in three different laboratory-scale fluidized bed combustors (FBCs). The beds` temperatures varied between 700 and 950 C, the oxygen partial pressure in the fluidizing gas varied from 0 to 21 kPa, the superficial gas velocity from 0.3 to 9 m/s, the voidage of the fluidized particles in the beds was usually 0.5 or 0.997, and the mean diameter of the fluidized particles was 200 or 900 {micro}m. A dynamic simulation model has been developed to describe the behavior of a single fuel particle during its lifetime in a combustor. The model considers drying, devolatilization, volatile and char combustion, external and internal heat and mass transfer, and changing fuel properties. Calculated temperature profiles and emission data are in good agreement with observations.

  17. High-fidelity simulations for clean and efficient combustion of alternative fuels

    NASA Astrophysics Data System (ADS)

    Chen, J. H.; Yoo, C. S.; Sankaran, R.; Oefelein, J. C.

    2008-07-01

    The monolithic nature of transportation technologies offers opportunities for significant improvements in efficiency of 25-50% through strategic technical investments in both advanced fuels and new low-temperature engine concepts. The application of direct numerical simulation (DNS) provides a way to study fundamental issues related to small-scale combustion processes in well-defined canonical configurations, whereas the application of large eddy simulation (LES) provides a formal treatment of the full range of time and length scales that exist in turbulent reacting flows, and thus provides a direct link to experimental studies of relevant combustion devices. In the present study, through DOE INCITE and Oak Ridge National Laboratory 250 Tflop Transition-to-Operations grants in 2008, DNS is performed to understand how a lifted autoignitive flame is stabilized, and LES is performed to understand the high-pressure injection and mixing processes in internal combustion engines. Understanding of these and other fundamental issues is needed to develop robust and reliable ignition and combustion models for the combustion regimes observed under low-temperature combustion engine environments using alternative fuels.

  18. Combustion of hydrogen-based mixtures in gas-fueled reciprocating engines

    NASA Astrophysics Data System (ADS)

    Smygalina, A. E.; Zaitchenko, V. M.; Ivanov, M. F.; Kiverin, A. D.

    2015-12-01

    The research is devoted to the possibility for application of hydrogen accumulated from renewable energy sources as a fuel for a reciprocating engine, which serves as an electrical generator drive. Hydrogen combustion in the chamber of a reciprocating engine, as a rule, occurs in a detonation mode. In order to obtain less hard modes, the present research proposes the usage of steam additions to hydrogen-air mixture or lean hydrogen-air mixtures. Mathematical simulation is used for investigation of combustion of mentioned mixtures in the combustion chamber of a reciprocating engine with a spark-plug ignition. The comparison of the usage of hydrogen-steam-air mixtures and lean hydrogen-air mixtures as fuels is given. The dependence of arising combustion modes and its quantitative characteristics on hydrogen content in combustible composition is investigated. The analysis of optimal combustion is presented, which is based on the consideration of two parameters: peak pressure in one cycle and the crankshaft angle corresponding to the achievement of the peak pressure.

  19. 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.

  20. 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.

  1. Combustion physics

    NASA Astrophysics Data System (ADS)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  2. Reduced Gravity Studies of Soret Transport Effects in Liquid Fuel Combustion

    NASA Technical Reports Server (NTRS)

    Shaw, Benjamin D.

    2004-01-01

    Soret transport, which is mass transport driven by thermal gradients, can be important in practical flames as well as laboratory flames by influencing transport of low molecular weight species (e.g., monatomic and diatomic hydrogen). In addition, gas-phase Soret transport of high molecular weight fuel species that are present in practical liquid fuels (e.g., octane or methanol) can be significant in practical flames (Rosner et al., 2000; Dakhlia et al., 2002) and in high pressure droplet evaporation (Curtis and Farrell, 1992), and it has also been shown that Soret transport effects can be important in determining oxygen diffusion rates in certain classes of microgravity droplet combustion experiments (Aharon and Shaw, 1998). It is thus useful to obtain information on flames under conditions where Soret effects can be clearly observed. This research is concerned with investigating effects of Soret transport on combustion of liquid fuels, in particular liquid fuel droplets. Reduced-gravity is employed to provide an ideal (spherically-symmetrical) experimental model with which to investigate effects of Soret transport on combustion. The research will involve performing reduced-gravity experiments on combustion of liquid fuel droplets in environments where Soret effects significantly influence transport of fuel and oxygen to flame zones. Experiments will also be performed where Soret effects are not expected to be important. Droplets initially in the 0.5 to 1 mm size range will be burned. Data will be obtained on influences of Soret transport on combustion characteristics (e.g., droplet burning rates, droplet lifetimes, gas-phase extinction, and transient flame behaviors) under simplified geometrical conditions that are most amenable to theoretical modeling (i.e., spherical symmetry). The experiments will be compared with existing theoretical models as well as new models that will be developed. Normal gravity experiments will also be performed.

  3. Modified Combustion Synthesis of ZnO Nanoparticles Using Renewable Fuel

    NASA Astrophysics Data System (ADS)

    Shah, N. N. H.; >H Misran, N. A. A.; Salim, M. A.; Othman, S. Z.; >A Manap,

    2013-06-01

    Zinc oxide nanoparticles were successfully synthesized using cost effective modified combustion synthesis route employing zinc nitrate hexahydrate as oxidant and palm oil derived C8 fatty alcohol as fuel in various ratios. The calcined zinc oxide exhibited hexagonal phase with wurtzite structure. The crystallite sizes of the samples were ranging from ca. 28 to 40 nm. Therefore, palm oil derived C8 fatty alcohol successfully played the role as low-cost and renewable fuel to synthesize zinc oxide nanoparticles.

  4. Airfoil cooling hole plugging by combustion gas impurities of the type found in coal derived fuels

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.; Lowell, C. E.

    1979-01-01

    The plugging of airfoil cooling holes by typical coal-derived fuel impurities was evaluated using doped combustion gases in an atmospheric pressure burner rig. Very high specific cooling air mass flow rates reduced or eliminated plugging. The amount of flow needed was a function of the composition of the deposit. It appears that plugging of film-cooled holes may be a problem for gas turbines burning coal-derived fuels.

  5. Black carbon emissions reductions from combustion of alternative jet fuels

    NASA Astrophysics Data System (ADS)

    Speth, Raymond L.; Rojo, Carolina; Malina, Robert; Barrett, Steven R. H.

    2015-03-01

    Recent measurement campaigns for alternative aviation fuels indicate that black carbon emissions from gas turbines are reduced significantly with the use of alternative jet fuels that are low in aromatic content. This could have significant climate and air quality-related benefits that are currently not accounted for in environmental assessments of alternative jet fuels. There is currently no predictive way of estimating aircraft black carbon emissions given an alternative jet fuel. We examine the results from available measurement campaigns and propose a first analytical approximation (termed 'ASAF') of the black carbon emissions reduction associated with the use of paraffinic alternative jet fuels. We establish a relationship between the reduction in black carbon emissions relative to conventional jet fuel for a given aircraft, thrust setting relative to maximum rated thrust, and the aromatic volume fraction of the (blended) alternative fuel. The proposed relationship is constrained to produce physically meaningful results, makes use of only one free parameter and is found to explain a majority of the variability in measurements across the engines and fuels that have been tested.

  6. FEANICS: A Multi-User Facility For Conducting Solid Fuel Combustion Experiments On ISS

    NASA Technical Reports Server (NTRS)

    Frate, David T.; Tofil, Todd A.

    2001-01-01

    The Destiny Module on the International Space Station (ISS) will soon be home for the Fluids and Combustion Facility's (FCF) Combustion Integrated Rack (CIR), which is being developed at the NASA Glenn Research Center in Cleveland, Ohio. The CIR will be the platform for future microgravity combustion experiments. A multi-user mini-facility called FEANICS (Flow Enclosure Accommodating Novel Investigations in Combustion of Solids) will also be built at NASA Glenn. This mini-facility will be the primary means for conducting solid fuel combustion experiments in the CIR on ISS. The main focus of many of these solid combustion experiments will be to conduct basic and applied scientific investigations in fire-safety to support NASA's Bioastronautics Initiative. The FEANICS project team will work in conjunction with the CIR project team to develop upgradeable and reusable hardware to meet the science requirements of current and future investigators. Currently, there are six experiments that are candidates to use the FEANICS mini-facility. This paper will describe the capabilities of this mini-facility and the type of solid combustion testing and diagnostics that can be performed.

  7. Utilization of ventilation air methane as a supplementary fuel at a circulating fluidized bed combustion boiler.

    PubMed

    You, Changfu; Xu, Xuchang

    2008-04-01

    Ventilation air methane (VAM) accounts for 60-80% of the total emissions from coal mining activities in China, which is of serious greenhouse gas concerns as well as a waste of valuable fuel sources. This contribution evaluates the use of the VAM utilization methods as a supplementary fuel at a circulating fluidized bed combustion boiler. The paper describes the system design and discusses some potential technical challenges such as methane oxidation rate, corrosion, and efficiency. Laboratory experimentation has shown that the VAM can be burnt completely in circulated fluidized bed furnaces, and the VAM oxidation does not obviously affect the boiler operation when the methane concentration is less than 0.6%. The VAM decreased the incomplete combustion loss for the circulating fluidized bed combustion furnace. The economic benefit from the coal saving insures that the proposed system is more economically feasible. PMID:18505001

  8. Laser Spectrometric Measurement System for Local Express Diagnostics of Flame at Combustion of Liquid Hydrocarbon Fuels

    NASA Astrophysics Data System (ADS)

    Kobtsev, V. D.; Kozlov, D. N.; Kostritsa, S. A.; Smirnov, V. V.; Stel'makh, O. M.; Tumanov, A. A.

    2016-03-01

    A laboratory laser spectrometric measurement system for investigation of spatial distributions of local temperatures in a flame at combustion of vapors of various liquid hydrocarbon fuels in oxygen or air at atmospheric pressure is presented. The system incorporates a coherent anti-Stokes Raman spectrometer with high spatial resolution for local thermometry of nitrogen-containing gas mixtures in a single laser shot and a continuous operation burner with a laminar diffusion flame. The system test results are presented for measurements of spatial distributions of local temperatures in various flame zones at combustion of vapor—gas n-decane/nitrogen mixtures in air. Its applicability for accomplishing practical tasks in comparative laboratory investigation of characteristics of various fuels and for research on combustion in turbulent flames is discussed.

  9. Developments in integrated pollutant removal for low-emission oxy-fuel combustion

    SciTech Connect

    Gerdemann, Stephen J.; Summers, Cathy A.; Oryshchyn, Danylo B.; Patrick, Brian; Ochs, Thomas L.

    2005-09-01

    A complete coal combustion and flue gas treatment scheme was designed, constructed, and operated at bench scale as a product of cooperative research between US DOE’s Albany Research Center (ARC) and Jupiter Oxygen Corporation. The combustion gas generated using this oxy-fuel coal combustion process was effectively captured using an integrated pollutant removal (IPR) process. Supporting laboratory-scale research focuses on elements of IPR such as extraction of particulates, SO2, and mercury, and on the character of the liquid and vapor phase compositions for the CO2 - N2 - O2 mixture at the temperature and pressure conditions found at the end of the process. Future pilot-scale work will be necessary to generate economic and engineering data that will apply to full-scale oxy-fuel/IPR systems.

  10. Cogeneration system with low NO sub x combustion of fuel gas

    SciTech Connect

    Garbo, P.W.

    1991-06-25

    This patent describes a cogeneration system for the production of electricity and refrigeration with low NO{sub x} combustion of fuel gas supplied at a high pressure. It comprises a heat exchanger to heat the fuel gas at high pressure; a turbo-expander connected to receive and expand the heated fuel gas from the heat exchanger; a centrifugal compressor driven by the turbo-expander the compressor being the refrigerant compressor of a refrigeration system; a porous fiber burner connected to receive the expanded fuel gas from the turbo-expander together with the requisite combustion air; a high-pressure steam boiler heated by the combustion of the expanded fuel gas on the outer surface of the porous fiber burner, the boiler being connected to pass the resulting flue gas with low NO{sub x} content through the heat exchanger to heat the fuel gas at high pressure; a steam turbine connected to receive and expand highpressure steam from the boiler and to return expanded and condensed steam to the boiler; and an electric generator driven by the steam turbine.

  11. Characteristics of soot emitted from combustion of municipal waste fuels

    SciTech Connect

    Levendis, Y.A.; Shemwell, B.E.

    2000-07-01

    This manuscript reports on particulate emissions (mainly soot) from laboratory combustion of typical municipal waste plastics, such as poly(styrene)(PS), poly(propylene)(PP), poly(methylmethacrylate)(PMMA), and poly(vinyl chloride)(PVC). In this experimental study combustion took place in a laboratory-scale, electrically-heated, drop-tube furnace at a gas temperature of 1,500 K, in air. The bulk (global) equivalence ratio, {phi}, was varied in the range of 0.5--1.5 and the gas residence time in the nearly-isothermal radiation zone of the furnace was {approximately}1 sec. The particle emissions were size-classified at the exit of the furnace, using a multi-stage inertial particle impactor. Combustion of PS yielded the highest amounts of soot (most highly agglomerated), several times more than the rest of the polymers. Substantial amounts of soot agglomerates were larger than 10 {micro}m. At this temperature <35% of the soot mass was PM{sub 2.5} (2.5 {micro}m or smaller). Soot yields increased with increasing bulk equivalence ratio in the furnace. The emissions from PE and PP were remarkably similar to each other, but strikingly different than those from PS. These polymers produced very low emissions at {phi} {le} 0.5, but emissions increased drastically with {phi}, and most of the soot was very fine (70--97% of the mass was PM{sub 2.5} depending on {phi}). Emissions from the combustion of PMMA were comparatively low and were the least influenced by the bulk {phi}; 80--95% of the emissions were PM{sub 2.5}. Combustion of PVC yielded relatively low amounts of soot; moreover, only 13--34% of the mass was PM{sub 2.5}. Hence, comparatively, PS produced the highest amounts of fine particulates followed by PP, PE, and PMMA, and then PVC. Burning these materials with excess oxygen drastically reduced the particulate emissions from PE and PP, substantially reduced those from PS, and mildly reduced those from PMMA and PVC.

  12. 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.

  13. CHARACTERIZATION OF FINE PARTICULATE MATTER PRODUCED BY COMBUSTION OF RESIDUAL FUEL OIL

    EPA Science Inventory

    Combustion experiments were carried out on four different residual fuel oils in a 732-kW boiler. PM emission samples were separated aerodynamically by a cyclone into fractions that were nominally less than (PM2.5) and greater (PM2.5+) that 2.5 micrometers in diameter. However, ex...

  14. 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...

  15. 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.

  16. 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...

  17. Future restrictions on diesel fuel combustion in California: Energy and emissions implications of four scenarios

    SciTech Connect

    Saricks, C.L.; Rote, D.M.; Stodolsky, F.; Eberhardt, J.J.

    1999-10-26

    The paper discusses alternatives to diesel displacement, describing several scenarios. It studies three basic cases: (1) cars and trucks; (2) urban buses; and (3) off-road vehicles. The discussion also includes changes in energy use and emissions expected from the production and combustion of alternative fuels.

  18. 40 CFR 60.107a - Monitoring of emissions and operations for fuel gas combustion devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Monitoring of emissions and operations for fuel gas combustion devices. 60.107a Section 60.107a Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  19. Combustible coal/water mixture for fuels and method of preparing same

    SciTech Connect

    Sawyer, E.W. Jr.

    1985-03-19

    Combustible fuel slurry compositions and methods for producing such compositions. The compositions comprise mixtures of particulate coal, water, wetting/dispersing agents for the coal and suspending agents for stabilizing the slurries. The suspending agents include clays such as attapulgite, sepiolite, bentonite and montmorillonite. The wetting/dispersing agents include anionic and non-ionic surface active agents.

  20. CARCINOGENICITY OF HOUSEHOLD SOLID FUEL COMBUSTION AND OF HIGH-TEMPERATURE FRYING

    EPA Science Inventory

    In October, 2006, 19 scientists from eight countries met at the International Agency for Research on Cancer (IARC) in Lyon, France, to assess the carcinogenicity of household solid fuel combustion (coal and biomass) and of high-temperature frying. These assessments will be publi...

  1. 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

  2. Combustion characteristics of hydrogen. Carbon monoxide based gaseous fuels

    NASA Technical Reports Server (NTRS)

    Notardonato, J. J.; White, D. J.; Kubasco, A. J.; Lecren, R. T.

    1981-01-01

    An experimental rig program was conducted with the objective of evaluating the combuston performance of a family of fuel gases based on a mixture of hydrogen and carbon monoxide. These gases, in addition to being members of a family, were also representative of those secondary fuels that could be produced from coal by various gasification schemes. In particular, simulated Winkler, Lurgi, and Blue-water low and medium energy content gases were used as fuels in the experimental combustor rig. The combustor used was originally designed as a low NOx rich-lean system for burning liquid fuels with high bound nitrogen levels. When used with the above gaseous fuels this combustor was operated in a lean-lean mode with ultra long residence times. The Blue-water gas was also operated in a rich-lean mode. The results of these tests indicate the possibility of the existence of an 'optimum' gas turbine hydrogen - carbon monoxide based secondary fuel. Such a fuel would exhibit NOx and high efficiency over the entire engine operating range. It would also have sufficient stability range to allow normal light-off and engine acceleration. Solar Turbines Incorporated would like to emphasize that the results presented here have been obtained with experimental rig combustors. The technologies generated could, however, be utilized in future commercial gas turbines.

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

    SciTech Connect

    Whitney, K.A.

    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.

  4. Oxy-fuel Combustion and Integrated Pollutant Removal as Retrofit Technologies for Removing CO2 from Coal Fired Power Plants

    SciTech Connect

    Ochs, T.L.; Oryshchyn, D.B.; Summers, C.A.; Gerdemann, S.J.

    2001-01-01

    One third of the US installed capacity is coal-fired, producing 49.7% of net electric generation in 20051. Any approach to curbing CO2 production must consider the installed capacity and provide a mechanism for preserving this resource while meeting CO2 reduction goals. One promising approach to both new generation and retrofit is oxy-fuel combustion. Using oxygen instead of air as the oxidizer in a boiler provides a concentrated CO2 combustion product for processing into a sequestration-ready fluid.... Post-combustion carbon capture and oxy-fuel combustion paired with a compression capture technology such as IPR are both candidates for retrofitting pc combustion plants to meet carbon emission limits. This paper will focus on oxy-fuel combustion as applied to existing coal power plants.

  5. 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.

  6. 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.

  7. 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)

  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. Investigation of sources, properties and preparation of distillate test fuels

    NASA Technical Reports Server (NTRS)

    Bowden, J. N.; Erwin, J.

    1983-01-01

    Distillate test fuel blends were generated for prescribed variations in composition and physical properties. Fuels covering a wide range in properties and composition which would provide a matrix of fuels for possible use in future combustion research programs were identified. Except for tetralin the blending components were all from typical refinery streams. Property variation blends span a boiling range within 150 C to 335 C, freezing point -23 C to -43 C, aromatic content 20 to 50 volume percent, hydrogen content 11.8 to 14.2 mass percent, viscosity 4 and 11 cSt (-20 C), and naphthalenes 8 and 16 volume percent. Composition variation blends were made with two base stocks, one paraffinic and the other napthenic. To each base stock was added each of three aromatic type fuels (alkyl benzenes, tetralin, and naphthalenes) for assigned initial boiling point, final boiling point, and hydrogen content. The hydrogen content was 13.5 mass percent for the paraffinic base stock blends and 12.5 mass percent and 11.5 mass percent for the naphthenic base stock blends. Sample 5-gallon quantities of all blends were prepared and analyzed.

  10. Chemical Kinetic Simulation of the Combustion of Bio-based Fuels

    SciTech Connect

    Ashen, Ms. Refuyat; Cushman, Ms. Katherine C.

    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.

  11. Air emission from the co-combustion of alternative derived fuels within cement plants: Gaseous pollutants.

    PubMed

    Richards, Glen; Agranovski, Igor E

    2015-02-01

    Cement manufacturing is a resource- and energy-intensive industry, utilizing 9% of global industrial energy use while releasing more than 5% of global carbon dioxide (CO₂) emissions. With an increasing demand of production set to double by 2050, so too will be its carbon footprint. However, Australian cement plants have great potential for energy savings and emission reductions through the substitution of combustion fuels with a proportion of alternative derived fuels (ADFs), namely, fuels derived from wastes. This paper presents the environmental emissions monitoring of 10 cement batching plants while under baseline and ADF operating conditions, and an assessment of parameters influencing combustion. The experiential runs included the varied substitution rates of seven waste streams and the monitoring of seven target pollutants. The co-combustion tests of waste oil, wood chips, wood chips and plastic, waste solvents, and shredded tires were shown to have the minimal influence when compared to baseline runs, or had significantly reduced the unit mass emission factor of pollutants. With an increasing ADF% substitution, monitoring identified there to be no subsequent emission effects and that key process parameters contributing to contaminant suppression include (1) precalciner and kiln fuel firing rate and residence time; (2) preheater and precalciner gas and material temperature; (3) rotary kiln flame temperature; (4) fuel-air ratio and percentage of excess oxygen; and (5) the rate of meal feed and rate of clinker produced. PMID:25947054

  12. Water cooled vibrating grate stoker for proven, efficient and reliable combustion of biomass fuels

    SciTech Connect

    Giaier, T.A.

    1996-12-31

    Bioenergy from waste sources and dedicated crops can provide substantial contributions for energy production. Together, these energy technologies are the wave of the future as they offer a localized, decentralized way of meeting electricity and process steam needs. The biomass industry accounts for about 15% of energy production worldwide, according to the National Wood Energy Association. For developing countries, the percentage is much higher. Currently, many types of combustible solid waste products like bark, wood waste, wood chips, sawdust, municipal and industrial refuse, agricultural wastes such as bagasse, spent coffee, etc.; are profitably utilized as excellent fuel sources. Many of these produce less acid gas than the fossil fuels they replace. Additionally, biomass feed stocks can reduce the quantity of carbon dioxide CO{sub 2} over fossil fuel burning since CO{sub 2} is used in the growth cycle of biomass feed stocks. Water cooled grates, both vibrating and stationary, have been used for many years for the combustion of biomass fuels. Both grates have relatively low maintenance and operating costs, thus making each grate a popular choice for a wide variety of applications. This paper chronicles combustion technologies for biomass fuels and the development of the water cooled grate followed by two case histories. The first case describes the conversion of an existing black liquor recovery boiler to wood firing and the second is the installation of the largest biomass fired Independent Power Producing plant in North America.

  13. Oxy-fuel combustion characteristics and kinetics of microalgae Chlorella vulgaris by thermogravimetric analysis.

    PubMed

    Chen, Chunxiang; Lu, Ziguang; Ma, Xiaoqian; Long, Jun; Peng, Yuning; Hu, Likun; Lu, Quan

    2013-09-01

    Oxy-fuel or O2/CO2 combustion technology was used to investigate the combustion of Chlorella vulgaris by thermogravimetric analysis (TGA). Oxy-fuel combustion occurs in an O2/CO2 atmosphere instead of an O2/N2 atmosphere and offers an alternative method of C. vulgaris preparation for biofuels processing. Our results show that three stages were observed during C. vulgaris combustion and the main combustion process occurred at the second stage. Compared with a 20%O2/80%N2 atmosphere, the mass loss rate at the DTG peaks (Rp) and the average reaction rate (Rv) in a 20%O2/80%CO2 atmosphere was lower, while the ignition temperature (TI) was higher. As oxygen concentration increases in an O2/CO2 atmosphere, Rp, Rv and the apparent activation energy (E) increases, while TI, the final temperature detected as mass stabilization (Tf) and the residue mass (Mr) decreases; As the heating rate (β) increases, TI, Tf and Rp increase, while Mr decreases. PMID:23890976

  14. Waste plastics as supplemental fuel in the blast furnace process: improving combustion efficiencies.

    PubMed

    Kim, Dongsu; Shin, Sunghye; Sohn, Seungman; Choi, Jinshik; Ban, Bongchan

    2002-10-14

    The possibility of using waste plastics as a source of secondary fuel in a blast furnace has been of recent interest. The success of this process, however, will be critically dependent upon the optimization of operating systems. For instance, the supply of waste plastics must be reliable as well as economically attractive compared with conventional secondary fuels such as heavy oil, natural gas and pulverized coal. In this work, we put special importance on the improvement of the combustibility of waste plastics as a way to enhance energy efficiency in a blast furnace. As experimental variables to approach this target, the effects of plastic particle size, blast temperature, and the level of oxygen enrichment were investigated using a custom-made blast model designed to simulate a real furnace. Lastly, the combustion efficiency of the mixture of waste plastics and pulverized coal was tested. The observations made from these experiments led us to the conclusion that with the increase of both blast temperature and the level of oxygen enrichment, and with a decrease in particle size, the combustibility of waste polyethylene could be improved at a given distance from the tuyere. Also it was found that the efficiency of coal combustion decreased with the addition of plastics; however, the combustion efficiency of mixture could be comparable at a longer distance from the tuyere. PMID:12220825

  15. Investigating an annular nozzle on combustion products of hydrocarbon fuels

    NASA Astrophysics Data System (ADS)

    Levin, V. A.; Afonina, N. E.; Gromov, V. G.; Smekhov, G. D.; Khmelevsky, A. N.; Markov, V. V.

    2013-09-01

    Full-scale and computational experiments were used to investigate the flows in the jet thrust unit with annular nozzle and deflector in the form of a spherical segment. The used working gas was the combustion products of air mixtures with acetylene, gas-phase aviation kerosene, and natural gas. Experimental studies were carried out in a hot-shot wind tunnel in the range of stagnation pressure from 0.48 to 2.05 MPa. The calculations for the cases of combustion products outflow in terrestrial and high altitude conditions were performed with the original computer program that used the Euler and Navier-Stokes systems supplemented by equations of chemical kinetics. It was found that the thrust of the jet module with an annular nozzle at high altitude almost twice exceeds the sound nozzle thrust, but is lesser (about 25 %) than the thrust of the ideal calculated Laval nozzle; the difference therewith decreases markedly with the decrease of flight altitude and stagnation pressure.

  16. Fuel Effects on Combustion and Emissions of a Direct-Inection Diesel Engine Operating at Moderate to High Engine Speed and Load

    SciTech Connect

    Szybist, James P; Szymkowicz, Patrick G.; Northrop, William F

    2012-01-01

    It is advantageous to increase the specific power output of diesel engines and to operate them at higher load for a greater portion of a driving cycle to achieve better thermal efficiency and thus reduce vehicle fuel consumption. Such operation is limited by excessive smoke formation at retarded injection timing and high rates of cylinder pressure rise at more advanced timing. Given this window of operation, it is desired to understand the influence of fuel properties such that optimum combustion performance and emissions can be retained over the range of fuels commonly available in the marketplace. It has been shown in previous studies that varying cetane number (CN) of diesel fuel has little effect on ignition delay at high engine load due to the domination of high cylinder temperature on ignition kinetics. The work here experimentally confirms that finding but also shows that emissions and combustion performance vary according to fuel reactivity. Data are examined from a direct-injection single cylinder research engine for eight common diesel fuels including soy-based biodiesel blends at two high load operating points with no exhaust gas recirculation (EGR) and at a moderate load with four levels of EGR. It is shown in the work that at high engine load where combustion is controlled by mixing processes, CN and other fuel properties have little effect on engine performance, although lower CN fuels produce a small increase in noise, smoke and CO emissions. Biodiesel blends increase NOX emissions and decreases CO and smoke emissions at high load, but otherwise have little effect on performance. At moderate load, higher CN fuels are more tolerant to EGR due to their better chemical reactivity at retarded injection timing, but all fuels produce comparable thermal efficiency at advanced combustion phasing regardless of EGR. In contrast to the high load conditions, there was no increase in NOX emissions for biodiesel at the moderate load condition. It is concluded that although higher CN does not significantly alter ignition delay at moderate to high loads it has a dominant influence on the acceptable injection timing range. Apart from CN effects, fuel oxygen content plays an independent role in reducing some emissions. It is therefore recommended that compensation for fuel ignitability and oxygen content be included in combustion control strategies to optimize emissions and performance of future diesel engines.

  17. Trends of jet fuel demand and properties

    NASA Technical Reports Server (NTRS)

    Friedman, R.

    1984-01-01

    Petroleum industry forecasts predict an increasing demand for jet fuels, a decrease in the gasoline-to-distillate (heavier fuel) demand ratio, and a greater influx of poorer quality petroleum in the next two to three decades. These projections are important for refinery product analyses. The forecasts have not been accurate, however, in predicting the recent, short term fluctuations in jet fuel and competing product demand. Changes in petroleum quality can be assessed, in part, by a review of jet fuel property inspections. Surveys covering the last 10 years show that average jet fuel freezing points, aromatic contents, and smoke points have trends toward their specification limits.

  18. Fuel Vaporization and Its Effect on Combustion in a High-Speed Compression-Ignition Engine

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Waldron, C D

    1933-01-01

    The tests discussed in this report were conducted to determine whether or not there is appreciable vaporization of the fuel injected into a high-speed compression-ignition engine during the time available for injection and combustion. The effects of injection advance angle and fuel boiling temperature were investigated. The results show that an appreciable amount of the fuel is vaporized during injection even though the temperature and pressure conditions in the engine are not sufficient to cause ignition either during or after injection, and that when the conditions are such as to cause ignition the vaporization process affects the combustion. The results are compared with those of several other investigators in the same field.

  19. Low NOx heavy fuel combustor concept program. Phase 1: Combustion technology generation

    NASA Astrophysics Data System (ADS)

    Lew, H. G.; Carl, D. R.; Vermes, G.; Dezubay, E. A.; Schwab, J. A.; Prothroe, D.

    1981-10-01

    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.

  20. 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.

  1. Auto-Ignition and Combustion of Diesel Fuel in a Constant-Volume Bomb

    NASA Technical Reports Server (NTRS)

    Selden, Robert F

    1938-01-01

    Report presents the results of a study of variations in ignition lag and combustion associated with changes in air temperature and density for a diesel fuel in a constant-volume bomb. The test results have been discussed in terms of engine performance wherever comparisons could be drawn. The most important conclusions drawn from this investigation are: the ignition lag was essentially independent of the injected fuel quantity. Extrapolation of the curves for the fuel used shows that the lag could not be greatly decreased by exceeding the compression-ignition engines. In order to obtain the best combustion and thermal efficiency, it was desirable to use the longest ignition lag consistent with a permissible rate of pressure rise.

  2. Manipulation of combustion waves in carbon-nanotube/fuel composites by highly reactive Mg nanoparticles

    NASA Astrophysics Data System (ADS)

    Lee, Kang Yeol; Hwang, Hayoung; Shin, Dongjoon; Choi, Wonjoon

    2015-10-01

    Manipulating the interface of micro/nanostructured materials and chemical fuels can change the fundamental characteristics of combustion waves that are generated during a reaction. In this study, we report that Mg/MgO nanoparticles actively amplify the propagation of combustion waves at the interface of multi-walled carbon nanotubes (MWCNTs) and chemical fuels. Fuel/MWCNT and fuel/MWCNT-Mg/MgO composite films were prepared by a facile synthetic method. We present complete physiochemical characterization of these composite films and evaluate the propagating velocities and real-time surface temperatures of combustion waves. Mg/MgO nanoparticles at the interface enhanced the reaction front velocity by 41%. The resulting explosive reactions supplied additional thermal energy to the chemical fuel, accelerating flame propagation. Furthermore, the surface temperatures of the composites with Mg/MgO nanoparticles were much lower, indicating how the transient heat from the reaction would ignite the unreacted fuels at lower surface temperatures despite not reaching the necessary activation energy for a chain reaction. This mechanism contributed to thermopower waves that amplified the output voltage. Furthermore, large temperature gradients due to the presence of nanoparticles increased charge transport inside the nanostructured material, due to the increased thermoelectric effects. This manipulation could contribute to the active control of interfacially driven combustion waves along nanostructured materials, yielding many potential applications.Manipulating the interface of micro/nanostructured materials and chemical fuels can change the fundamental characteristics of combustion waves that are generated during a reaction. In this study, we report that Mg/MgO nanoparticles actively amplify the propagation of combustion waves at the interface of multi-walled carbon nanotubes (MWCNTs) and chemical fuels. Fuel/MWCNT and fuel/MWCNT-Mg/MgO composite films were prepared by a facile synthetic method. We present complete physiochemical characterization of these composite films and evaluate the propagating velocities and real-time surface temperatures of combustion waves. Mg/MgO nanoparticles at the interface enhanced the reaction front velocity by 41%. The resulting explosive reactions supplied additional thermal energy to the chemical fuel, accelerating flame propagation. Furthermore, the surface temperatures of the composites with Mg/MgO nanoparticles were much lower, indicating how the transient heat from the reaction would ignite the unreacted fuels at lower surface temperatures despite not reaching the necessary activation energy for a chain reaction. This mechanism contributed to thermopower waves that amplified the output voltage. Furthermore, large temperature gradients due to the presence of nanoparticles increased charge transport inside the nanostructured material, due to the increased thermoelectric effects. This manipulation could contribute to the active control of interfacially driven combustion waves along nanostructured materials, yielding many potential applications. Electronic supplementary information (ESI) available: The scheme of preparation of MWCNT and MWCNT-Mg films; characterization of MWCNT-Mg(NO3)2 composites; and distribution of Mg/MgO nanoparticles. See DOI: 10.1039/c5nr03795f

  3. Combustion parameters of spark ignition engine using waste potato bioethanol and gasoline blended fuels

    NASA Astrophysics Data System (ADS)

    Ghobadian, B.; Najafi, G.; Abasian, M.; Mamat, R.

    2015-12-01

    The purpose of this study is to investigate the combustion parameters of a SI engine operating on bioethanol-gasoline blends (E0-E20: 20% bioethanol and 80% gasoline by volume). A reactor was designed, fabricated and evaluated for bioethanol production from potato wastes. The results showed that increasing the bioethanol content in the blend fuel will decrease the heating value of the blended fuel and increase the octane number. Combustion parameters were evaluated and analyzed at different engine speeds and loads (1000-5000 rpm). The results revealed that using bioethanol-gasoline blended fuels will increase the cylinder pressure and its 1st and 2nd derivatives (P(θ), P•(θ) and P••(θ)). Moreover, using bioethanol- gasoline blends will increase the heat release (Q•(θ)) and worked of the cycle. This improvement was due to the high oxygen percentage in the ethanol.

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

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  5. Thermal conductivity and combustion properties of wheat gluten foams.

    PubMed

    Blomfeldt, Thomas O J; Nilsson, Fritjof; Holgate, Tim; Xu, Jianxiao; Johansson, Eva; Hedenqvist, Mikael S

    2012-03-01

    Freeze-dried wheat gluten foams were evaluated with respect to their thermal and fire-retardant properties, which are important for insulation applications. The thermal properties were assessed by differential scanning calorimetry, the laser flash method and a hot plate method. The unplasticised foam showed a similar specific heat capacity, a lower thermal diffusivity and a slightly higher thermal conductivity than conventional rigid polystyrene and polyurethane insulation foams. Interestingly, the thermal conductivity was similar to that of closed cell polyethylene and glass-wool insulation materials. Cone calorimetry showed that, compared to a polyurethane foam, both unplasticised and glycerol-plasticised foams had a significantly longer time to ignition, a lower effective heat of combustion and a higher char content. Overall, the unplasticised foam showed better fire-proof properties than the plasticized foam. The UL 94 test revealed that the unplasticised foam did not drip (form droplets of low viscous material) and, although the burning times varied, self-extinguished after flame removal. To conclude both the insulation and fire-retardant properties were very promising for the wheat gluten foam. PMID:22332837

  6. Stack contamination effects during small-scale combustion testing of synthetic fuels

    SciTech Connect

    Douglas, L.J.; Gibbon, G.A.; White, C.M.

    1984-01-01

    The Analytical Chemistry Branch at the Pittsburgh Energy Technology Center has undertaken the assessment of the possible environmental impact of substituting synfuels for petroleum-based fuels in utility and industrial boilers. The assessment is based on a study of results obtained from the analysis of trace organic compounds present in the exaust gases of a fully instrumented 20-hp firetube boiler. The stack gases from petroleum-based fuels, synfuels, and methanol combustion tests have been sampled and analyzed by combined gas chromatography/mass spectrometry. The stack gas sampled during the combustion of methanol showed the presence of saturated and aromatiic hydrocarbons as well as detectable amounts of organic sulfur compounds, such as dibenzothiophene. The presence of these compounds could not be explained on the basis of methanol showed the presence of saturated and aromatic hydrocarbons as well as detectable amounts of organic sulfur compounds, such as dibenzothiophene. The presence of these compounds could not be explained on the basis of methanol combustion but suggests contamination of the 20-hp combustor-exhaust system from earlier tests using petroleum or coal-derived fuels. The previously established exhaust stack protocol was reviewed by the Combustion Technology Branch and the Analytical Chemistry Branch. It was decided that a more exhaustive protocol was required. When this revised protocol was instituted, cross-contamination and memory effects disappeared, and sampling integrity was reestablished, thus allowing the analytical data to be properly interpreted. 5 references, 7 figures, 5 tables.

  7. Additives for increasing the completeness of combustion of diesel fuels

    SciTech Connect

    Popova, O.V.; Bashkatova, S.T.; Vasil`eva, E.N.

    1995-09-01

    Data on the consumption of hydrocarbon fuels indicate a stable trend toward increasing use of heavier fractions. This trend reflects the increasing use of tertiary oil recovery methods and more severe processing in the refinery. Another factor is the widespread dieselization of the automotive fleet. The field of application for diesel engines is expanding constantly; however, the use of heavier fuels results in higher toxicity of the exhaust gas and nozzle plugging in the engine. Another problem introduced with the increasing use of diesels is the greater amount of soot in the exhaust in comparison with carburetor engines. The simplest method for lowering the toxicity of engine exhaust is the use of fuels with antismoke additives. This paper reviews a number of additives and their effects: (1) carboxyl dispersants, (2) amino dispersants, (3) mannich dispersants, (4) products from the treatment of the previous three dispersants, and (5) polymeric dispersants.

  8. Determination of alternative fuels combustion products: Phase 1 report

    SciTech Connect

    Whitney, K.A.

    1997-09-01

    This report describes the laboratory effort to identify and quantify organic exhaust species generated from alternative-fueled light-duty vehicles operating over the Federal Test Procedure on compressed natural gas, liquefied petroleum gas, methanol, ethanol, and reformulated gasoline. The exhaust species from these vehicles were identified and quantified for fuel/air equivalence ratios of 0.8, 1.0, and 1.2, nominally, and were analyzed with and without a vehicle catalyst in place to determine the influence of a catalytic converter on species formation.

  9. Comparative analysis of monetary estimates of external environmental costs associated with combustion of fossil fuels

    SciTech Connect

    Koomey, J.

    1990-07-01

    Public utility commissions in a number of states have begun to explicitly treat costs of environmental externalities in the resource planning and acquisition process (Cohen et al. 1990). This paper compares ten different estimates and regulatory determinations of external environmental costs associated with fossil fuel combustion, using consistent assumptions about combustion efficiency, emissions factors, and resource costs. This consistent comparison is useful because it makes explicit the effects of various assumptions. This paper uses the results of the comparison to illustrate pitfalls in calculation of external environmental costs, and to derive lessons for design of policies to incorporate these externalities into resource planning. 38 refs., 2 figs., 10 tabs.

  10. Combustion of Gaseous Fuels with High Temperature Air in Normal- and Micro-gravity Conditions

    NASA Technical Reports Server (NTRS)

    Wang, Y.; Gupta, A. K.

    2001-01-01

    The objective of this study is determine the effect of air preheat temperature on flame characteristics in normal and microgravity conditions. We have obtained qualitative (global flame features) and some quantitative information on the features of flames using high temperature combustion air under normal gravity conditions with propane and methane as the fuels. This data will be compared with the data under microgravity conditions. The specific focus under normal gravity conditions has been on determining the global flame features as well as the spatial distribution of OH, CH, and C2 from flames using high temperature combustion air at different equivalence ratio.

  11. Oxy-fuel combustion systems for pollution free coal fired power generation

    SciTech Connect

    Ochs, Thomas L.; Oryshchyn, Danylo B.; Gross, Dietrich; Patrick, Brian; Gross, Alex; Dogan, Cindy; Summers, Cathy A.; Simmons, William; Schoenfeld, Mark

    2004-01-01

    Jupiter Oxygen's patented oxy-fuel combustion systems1 are capable of economically generating power from coal with ultra-low emissions and increased boiler efficiency. Jupiter's system uses pure oxygen as the combustion agent, excluding air and thus nitrogen, concentrating CO2 and pollutants for efficient capture with near zero NOx production, reducing exhaust mass flow, and increasing radiant heat transfer. Flue-gas recirculation rates can be varied to add flexibility to new boiler designs using this technology. Computer modeling and thermal analysis have identified important design considerations in retrofit applications.

  12. 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

  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. Electrical aspects of gaseous fuel flames for microgravity combustion and combustion control

    NASA Astrophysics Data System (ADS)

    Papac, Michael James

    This dissertation describes a fundamental study on the influence of electric fields on combustion reactions and their surrounding gases. A detailed literature survey is provided which outlines the works in the past that have contributed to the modern understanding of the fundamental processes. The interactions that occur when electric fields are applied to flames are complicated, and not enough information exists for electrode designs to be evaluated either by first principles or empirical correlations. Moreover, this prevents robust electric field actuators for control, a topic of great interest currently, from being developed without extensive testing. Electric field, chemical, and fluid-dynamic interactions that occur near the combustion reaction zone, and away from the reaction in the electrode spaces. Based on the results from the literature survey, an apparatus is constructed and a series of experiments are performed. A variety of diagnostics are used to probe flame shapes, sizes and the behaviors of the surrounding gases, as well as the characteristics of the electrical discharge from the flame. Techniques such as photography and schlieren imaging are employed for visualization, and chemiluminescence detection is used to probe the chemistry of the flame. In addition, ion probes are developed for measuring overall voltage-current characteristics and resolving the spatial distribution of ion current in the discharge. The system is analyzed analytically and a computational model is generated, providing a model of the system. The results of the model are used to elucidate the fundamental aspects of the system such as time constants, buoyancy characteristics, and chemical changes. Together, the combined experimental techniques and analysis provide a description of the fundamental processes that occur when electric fields are applied to flames beyond what is currently available and provides a method by which the design of such systems can be accomplished.

  15. COMBUSTION RESEARCH ON THE FATE OF FUEL-NITROGEN UNDER CONDITIONS OF PULVERIZED COAL COMBUSTION

    EPA Science Inventory

    The report gives results of an experimental investigation of coal pyrolysis and oxidation, and char oxidation to determine the effects of temperature and fuel/oxygen equivalence ratio on the conversion of coal-nitrogen to NOx. Experiments involved a laboratory laminar flow furnac...

  16. 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.

  17. 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.

  18. Influence of Standing Acoustic Waves on Combustion of Alternative Fuels

    NASA Astrophysics Data System (ADS)

    Teshome, Sophonias; Pezeshkian, Alec; Smith, Owen; Karagozian, Ann

    2008-11-01

    The present experimental study focuses on exposure of single burning fuel droplets to external acoustical excitation created in a cylindrical waveguide bounded by two loudspeakers. This configuration creates a relatively symmetric acoustic field whereby standing waves may be created, forming a pressure node (PN) or antinode (PAN) within the waveguide. A range of alternative liquid fuels is considered in these experiments, including ethanol, methanol, white gasoline, JP-8, and blends of JP-8 and liquid synthetic fuel. Droplet burning rates, flame characteristics, and their dependence on the position of the droplet relative to the PN and PAN are quantified. In some cases, large scale acoustic forcing is observed to cause flame deflection so strong that the effective acoustic radiation force appears to approach the magnitude of the buoyant force acting on the flames. Flame orientation is observed to change abruptly as the droplet position is moved from one side to the other relative to the PN or PAN, consistent with theory, although for very large amplitude acoustic forcing, the magnitude of the acoustic acceleration can exceed theoretical predictions. Variations in burning rates for a range of fuels and excitation conditions relevant to engine systems are quantified. Tanabe, et al., Proc. Comb. Inst. 30, p. 1957-1964, 2005

  19. 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.

  20. Method of regulating the amount of underfire air for combustion of wood fuels in spreader-stroke boilers

    DOEpatents

    Tuttle, Kenneth L.

    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.

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

    NASA Technical Reports Server (NTRS)

    Schultz, D. F.; Wolfbrandt, G.

    1980-01-01

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

  2. 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...

  3. 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.

    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.

  4. Fuel injection control system for internal combustion engine with asynchronous fuel injection for fuel supply resumption following temporary fuel cut-off

    SciTech Connect

    Mori, Y.

    1987-09-22

    This patent describes a fuel injection control system for an internal combustion engine comprising: a first sensor producing a first sensor signal representative of the angular position of the crank shaft; a second sensor producing a second sensor signal representative of preselected engine operating parameters; a third sensor detecting whether engine operating conditions satisfy a predetermined fuel cut-off condition and if so, producing a third sensor signal; fourth means for deriving a fuel injection amount on the basis of a value of the second sensor signal and producing a fuel injection control signal having a value indicative of the derived fuel injection amount; fifth means for disabling the fourth means in the presence of the third sensor signal and for resumption operation of the fourth means after the third sensor signal ends, sixth means for deriving fuel injection timing and producing an injection timing control signal, wherein the first sensor signal includes a first pulse train representative of predetermined angular positions of the crank shaft and a second pulse train representative of predetermined units of rotation of the crank shaft. The sixth means counts the pulses of the first and second pulse trains, produces the injection timing signal when the first pulses and second pulses reach given values and presets the first and second counter values to the first and second value in response to the third sensor signal.

  5. 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.

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

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    A monodisperse aerosol generator was modified to study ignition requirements, flammability limits, and flame speeds in the transition region. An ignition system was developed and tested. The fabrication of an optical drop sizing system is nearly complete. Preliminary measurements of droplet size effects on the minimum ignition energy for n-heptane sprays performed. Parameteric studies of droplet size effects on minimum ignition energies of various fuels including alcohols are in progress.

  7. Chlorinated organic compounds evolved during the combustion of blends of refuse-derived fuels and coals

    SciTech Connect

    Xiaodong Yang; Napier, J.; Sisk, B.; Wei-Ping Pan; Riley, J.T.; Lloyd, W.G.

    1996-12-31

    The objective of this study was to examine the possible formation of chlorinated organic compounds during the combustion of blends of refuse derived fuels (RDF) and coal under conditions similar to those of an atmospheric fluidized bed combustion (AFBC) system. A series of experiments were conducted using a TGA interfaced to FTIR and MS systems. Additional experiments using a tube furnace preheated to AFBC operating temperatures were also conducted. The combustion products were cryogenically trapped and analyzed with a GUMS system. The chlorination of phenols and the condensation reactions of chlorophenols were investigated in this study. A possible mechanism for the formation of chlorinated organic; compounds such as dibenzodioxins and dibenzofurans, by chlorination and condensation reactions involving phenols, was proposed.

  8. Stabilization of liquid hydrocarbon fuel combustion by using a programmable microwave discharge in a subsonic airflow

    SciTech Connect

    Kopyl, P. V.; Surkont, O. S.; Shibkov, V. M.; Shibkova, L. V.

    2012-06-15

    Under conditions of a programmable discharge (a surface microwave discharge combined with a dc discharge), plasma-enhanced combustion of alcohol injected into a subsonic (M = 0.3-0.9) airflow in the drop (spray) phase is stabilized. It is shown that the appearance of the discharge, its current-voltage characteristic, the emission spectrum, the total emission intensity, the heat flux, the electron density, the hydroxyl emission intensity, and the time dependences of the discharge current and especially discharge voltage change substantially during the transition from the airflow discharge to stabilized combustion of the liquid hydrocarbon fuel. After combustion stabilization, more than 80% of liquid alcohol can burn out, depending on the input power, and the flame temperature reaches {approx}2000 K.

  9. Accelerating the Computation of Detailed Chemical Reaction Kinetics for Simulating Combustion of Complex Fuels

    SciTech Connect

    Grout, Ray W

    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.

  10. 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.

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

    SciTech Connect

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

    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 on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e. maps); how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions 10 from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10% uncertainty (95% 15 confidence interval). Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. The information discussed in this manuscript synthesizes global, regional and national fossil-fuel carbon dioxide emissions, their distributions, their transport, and the associated uncertainties.

  12. Changes in combustion behavior of liquid fuels due to the addition of small amounts of ammonia borane or nano aluminum

    NASA Astrophysics Data System (ADS)

    Pfeil, Mark A.

    Both ammonia borane and nano aluminum as additives to liquid fuels are investigated. Both fundamental droplet combustion experiments and experiments using an unstable liquid rocket combustor are used to study the effects these additives on the combustion behavior. The liquid fuels consist of ethanol and JP-8. The droplet experiments consist of both visual and OH high speed planar laser-induced fluorescence measurements. Simple combustion models are incorporated as well to provide further understanding. It is found that ammonia borane increases the regression rate of a single ethanol droplet. Evidence indicates that hydrogen gas is released throughout the combustion process of the droplet and influences the combustion behavior notably. Laser diagnostics indicate that changes in flame structure occur. The other components of ammonia borane affect the combustion behavior of the droplet, especially near the end of the droplet lifetime, causing the droplet to shatter. Nano aluminum has very little impact on the combustion behavior of single fuel droplets of JP-8 and ethanol. Nano aluminum is observed to combust only when a surfactant, Neodol, is present which produces gas generation and bubble formation within the droplet. Combustor experiments show similar trends as the droplet combustion experiments. Ammonia borane has a notable impact on the combustion stability of the system allowing it to be unstable for more combustor geometries. It is shown that ammonia borane addition produces a bimodal unsteady energy release within the combustor while the neat fuel does not. This combustion behavior allows for the increased amount of unstable combustor geometries. Nano aluminum has a small impact on the combustion stability of the system causing pressure oscillations to increase.

  13. Fluidized bed combustion of pelletized biomass and waste-derived fuels

    SciTech Connect

    Chirone, R.; Scala, F.; Solimene, R.; Salatino, P.; Urciuolo, M.

    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)

  14. Advanced Combustion

    SciTech Connect

    Holcomb, Gordon R.

    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).

  15. Properties of jet engine combustion particles during the PartEmis experiment: Hygroscopicity at subsaturated conditions

    NASA Astrophysics Data System (ADS)

    Gysel, M.; Nyeki, S.; Weingartner, E.; Baltensperger, U.; Giebl, H.; Hitzenberger, R.; Petzold, A.; Wilson, C. W.

    2003-06-01

    Hygroscopic properties of combustion particles were measured online with a Hygroscopicity Tandem Differential Mobility Analyzer (H-TDMA) during PartEmis jet engine combustor experiments. The combustor was operated at old and modern cruise conditions with fuel sulfur contents (FSC) of 50, 410 and 1270 μg g-1, and hygroscopic growth factors (HGF) of particles with different dry diameters were investigated at relative humidities RH <= 95%. HGFs increased strongly with increasing FSC (HGF[95% RH, 50 nm, modern cruise] = 1.01 and 1.16 for low and high FSC, respectively), and decreased with increasing particle size at fixed FSC, whereas no significant difference was detected between old and modern cruise. HGFs agreed well with a two-parameter theoretical model which provided an estimate of the sulfuric acid content of dry particles, indicating a nearly linear dependence on FSC.

  16. Aircraft Research and Technology for Future Fuels

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The potential characteristics of future aviation turbine fuels and the property effects of these fuels on propulsion system components are examined. The topics that are discussed include jet fuel supply and demand trends, the effects of refining variables on fuel properties, shekle oil processing, the characteristics of broadened property fuels, the effects of fuel property variations on combustor and fuel system performance, and combuster and fuel system technology for broadened property fuels.

  17. Emissions from burning tire-derived fuel (TDF): Comparison of batch combustion of tire chips and continuous combustion of tire crumb mixed with coal

    SciTech Connect

    Levendis, Y.A.; Atal, A.; Carlson, J.B.

    1998-04-01

    This laboratory study investigated the emissions of waste automobile tire-derived fuel (TDF). This fuel was burned in two different modes, either segmented in small pieces (tire chunks) or in pulverized form (tire crumb). Tire chunks were burned in fixed beds in batch mode in a horizontal furnace. Tire crumb was burned in a continous flow mode, dispersed in air, either alone or mixed with pulverized coal, in a verical furnace. The gas flow was laminar, the gas temperature was 1000{degrees}C in all cases, and the residence times of the combustion products in the furnaces were similar. Chunks of waste tires had dimensions in the range of 3-9 {mu}m, tire crumb was size-classified to be 180-212 {mu}m and the high volatile bituminous coal, used herein, was 63-75. The fuel mass loading in the furnaces was varied. The following emissions were monitored at the exit of the furnaces: CO, CO{sub 2}, NO{sub x} polynuclear aromatic hydrocarbon (PAH) and particulates. Results showed that combustion of TDF in fixed beds resulted in large yields (emissions per mass of fuel burned) of CO, soot and PAHs. Such yields increased with the size of the bed. CO, soot and PAHs yields from batch combustion of fixed beds of coal were lower by more than an order of magnitude than those from fixed beds of TDF. Continuous pulverized fuel combustion of TDF (tire crumb) resulted in dramatically lower yields of CO, soot and PAHs than those from batch combustion, especially when TDF was mixed with pulverized coal. To the contrary, switching the mode of combustion of coal (from fixed beds to pulverized fuel) did not result in large differences in the aforementioned emissions. CO{sub 2}, and, especially, NO{sub x} yields from batch combustion of TDF were lower than those from coal. Emissions of NO{sub x} were somewhat lower from batch combustion than from pulverized fuel combustion of TDF and coal.

  18. Emissions from burning tire-derived fuel (TDF): Comparison of batch combustion of tire chips and continuous combustion of tire crumb mixed with coal

    SciTech Connect

    Levendis, Y.A.; Atal, A.; Carlson, J.B.

    1998-07-01

    This laboratory study investigated the emissions of waste automobile tire-derived fuel (TDF). This fuel was burned in two different modes, either segmented in small pieces (tire chunks) or in pulverized form (tire crumb). Tire chunks were burned in fixed beds in batch mode in a horizontal furnace. Tire crumb was burned in a continuous flow mode, dispersed in air, either alone or mixed with pulverized coal, in a vertical furnace. The gas flow was laminar, the gas temperature was 1,000 C in all cases, and the residence times of the combustion products in the furnaces were similar. Chunks of waste tires had dimensions in the range of 3--9 mm, tire crumb was size-classified to be 180--212 {micro}m and the high volatile bituminous coal, used herein, was 63--75{micro}m. The fuel mass loading in the furnaces was varied. The following emissions were monitored at the exit of the furnaces: CO, CO{sub 2}, NO{sub x}, polynuclear aromatic hydrocarbon (PAH) and particulates. Results showed that combustion of TDF in fixed beds resulted in large yields (emissions per mass of fuel burned) of CO, soot and PAHs. Such yields increased with the size of the bed. CO, soot and PAHs yields from batch combustion of fixed beds of coal were lower by more than an order of magnitude than those from fixed beds of TDF. Continuous pulverized fuel combustion of TDF (tire crumb) resulted in dramatically lower yields of CO, soot and PAHs than those from batch combustion, especially when TDF was mixed with pulverized coal. To the contrary, switching the mode of combustion of coal (from fixed beds to pulverized fuel) did not result in large differences in the aforementioned emissions. CO{sub 2}, and especially, NO{sub x} yields from batch combustion of TDF were lower than those from coal. Emissions of NO{sub x} were somewhat lower from batch combustion than from pulverized fuel combustion of TDF and coal.

  19. 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.

  20. Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

    NASA Technical Reports Server (NTRS)

    Tower, Leonard K; Gammon, Benson E

    1953-01-01

    The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.

  1. System approach to the analysis of an integrated oxy-fuel combustion power plant

    NASA Astrophysics Data System (ADS)

    Ziębik, Andrzej; Gładysz, Paweł

    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.

  2. 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.

  3. Characterization and Mutagenicity of Biomass Smoke from Peat and Red Oak Fuel under Smolder and Flame Combustions

    EPA Science Inventory

    Although wildfire smoke is known to cause adverse health effects, less is known about the relative effects of wildfire smoke from different fuel types or combustion conditions. In this study, we describe a novel in-tandem application of controlled combustion and cryo-trapping tec...

  4. The Impact of Zeolites During Co-Combustion of Municipal Sewage Sludge with Alkali and Chlorine Rich Fuels

    NASA Astrophysics Data System (ADS)

    Pettersson, A.; Elledt, A.-L.; Moöler, A.; Steenari, B.-M.; Åmand, L.-E.

    Municipal sewage sludge has proven to eliminate alkali metals and chlorine related problems during combustion of straw and refuse derived fuels (RDF). However, the mechanisms involved have not been clarified. The aim of this work was to gain more knowledge about the behaviour of sewage sludge and detergent zeolites in combustion and about their effects on alkali metal chemistry.

  5. Combined catalysts for the combustion of fuel in gas turbines

    SciTech Connect

    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. Comparative Investigation of Blade Lean Effect in Hydrogen-Fueled Combustion Turbine

    NASA Astrophysics Data System (ADS)

    Nakamura, R.; Suzuki, M.; Yamamoto, M.

    2011-09-01

    Recently, environmental problems have been actively researched all over the world. To overcome air pollution and fossil fuel exhaustion, we have been investigating a hydrogen-fueled propulsion system. In the system, hydrogen is injected from the turbine blade and/or vane surface. The system can realize higher power, lighter weight and lower emission than conventional systems. However, there exist many problems for the realization. One of them is the extremely high temperature region appearing on the wall. In the present study, we clarify the effect of blade lean on the generation of high temperature region. The combusting turbulent flowfield around a normal, a compound lean and a reverse compound lean blades are simulated, using RANS and 5-step reduced combustion model. Comparing the numerical results, it is confirmed that compound lean is promising to suppress the high temperature region.

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

    NASA Astrophysics Data System (ADS)

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

    2009-01-01

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

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

    SciTech Connect

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

    1997-06-01

    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, and ethanol. In the first 24 months of this program, studies of the oxygen rich, stoichiometric, and fuel-rich thermal degradation of these fuels in the temperature range of 300 to 1100{degrees}C at atmospheric pressure and for reaction times of 1.0 and 2.0 s were completed. Trace organic products were identified and quantified for each fuel as a function of temperature. The results of these studies agreed well with the results of tail-pipe emission studies in that the types and quantity of emissions measured in both the laboratory and engine tests were shown to be very similar under certain operating conditions. However, some chemicals were observed in the laboratory studies that were not observed in the engine studies and vice versa. This result is important in that it has implications concerning the origin of these emissions. Experiments concerning the NO perturbed oxidation of methanol, M85, ethanol, and E85 indicated the presence of complex oxidation chemistry. At mild temperatures, NO addition resulted in enhanced fuel conversion. At elevated temperatures, an inhibitory effect was observed through increased yields of both partial oxidation and pyrolysis-type reaction products. Comparison of flow reactor product distributions with engine test results generally indicated improved comparisons when NO was added to the fuel. Analysis of secondary components of alcohol fuels resulted in some unexpected observations. Several previously unidentified species were observed in these experiments which may impact atmospheric reactivity assessments of these fuels.

  9. Schlieren and OH* chemiluminescence imaging of combustion in a turbulent boundary layer over a solid fuel

    NASA Astrophysics Data System (ADS)

    Jens, Elizabeth T.; Miller, Victor A.; Cantwell, Brian J.

    2016-03-01

    Combustion in a turbulent boundary layer over a solid fuel is studied using simultaneous schlieren and OH* chemiluminescence imaging. The flow configuration is representative of a hybrid rocket motor combustor. Six different hydrocarbon fuels, including both classical hybrid rocket fuels and a high regression rate fuel (paraffin wax), are burned in an undiluted oxygen free-stream at pressures ranging from atmospheric to 1524.2 kPa (221.1 psi). A detailed explanation of methods for registering the schlieren and OH* chemiluminescence images to one another is presented, and additionally, details of the routines used to extract flow features of interest (like the boundary layer height and flame location) are provided. At atmospheric pressure, the boundary layer location is consistent between all fuels; however, the flame location varies for each fuel. The flame zone appears to be smoothly distributed over the fuel surface at atmospheric pressure. At elevated pressures and correspondingly increased Dahmköhler number (but at constant Reynolds number), flame morphology is markedly different, exhibiting large rollers in a shear layer above the fuel grain and finer structures in the flame. The chemiluminescence intensity is found to be roughly proportional to the fuel burn rate at both atmospheric and elevated chamber pressures.

  10. 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.

  11. Comparison of ash behavior of different fuels in fluidised bed combustion using advanced fuel analysis and global equilibrium calculations

    SciTech Connect

    Zevenhoven-Onderwater, M.; Blomquist, J.P.; Skrifvars, B.J.; Backman, R.; Hupa, M.

    1999-07-01

    The behavior of different ashes is predicted by means of a combination of an advanced fuel analysis and global equilibrium calculations. In order to cover a broad spectrum of fuels a coal, a peat, a forest residue and Salix (i.e. willow) are studied. The latter was taken with and without soil contamination, i.e. with a high and low content of silica , respectively. It is shown that mineral matter in fossil and biomass fuels can be present in the matrix of the fuel itself or as included minerals. Using an advanced fuel analysis, i.e. a fractionation method, this mineral content can be divided into four fractions. The first fraction mainly contains those metal ions, that can be leached out of the fuel by water and mainly contains alkali sulfates, carbonates and chlorides. The second fraction mainly consists of those ions leached out by ammonium acetate and covers those ions, that are connected to the organic matrix. The third fraction contains the metals leached out by hydrochloric acid and contains earth alkali carbonates and sulfates as well as pyrites. The rest fraction contains those minerals, that are not leached out by any of the above mentioned solvents, such as silicates. A global equilibrium analysis is used to predict the thermal and chemical behavior of the combined first and second fractions and of the combined third and rest fractions under pressurized and/or atmospheric combustion conditions. Results of both the fuel analysis and the global equilibrium analysis are discussed and practical implications for combustion processes are pointed out.

  12. Advanced combustion, emission control, health impacts, and fuels merit review and peer evaluation

    SciTech Connect

    None, None

    2006-10-01

    This report is a summary and analysis of comments from the Advisory Panel at the FY 2006 DOE National Laboratory Advanced Combustion, Emission Control, Health Impacts, and Fuels Merit Review and Peer Evaluation, held May 15-18, 2006 at Argonne National Laboratory. The work evaluated in this document supports the FreedomCAR and Vehicle Technologies Program. The results of this merit review and peer evaluation are major inputs used by DOE in making its funding decisions for the upcoming fiscal year.

  13. Formation and control of combustion pollutants from gasoline-fueled spark-ignition motor vehicle engines

    NASA Astrophysics Data System (ADS)

    Bozek, John W.

    1992-11-01

    The purpose of the report is to provide simple explanations regarding the formation and control of combustion pollutants from gasoline-fueled spark-ignition motor vehicle engines. Formation phenomena are explained on the basis of well-known cause and effect relationships. Pollution control techniques are explained on the basis of the operating characteristics of systems which are already in widespread use. Two appendices are included which present additional information.

  14. Separation of carbon dioxide with the use of chemical-looping combustion and gasification of fuels

    NASA Astrophysics Data System (ADS)

    Ryabov, G. A.; Folomeev, O. M.; Litun, D. S.; Sankin, D. A.

    2009-06-01

    Matters regarding using new technology for chemical-looping combustion of fuels for solving the problem of separation and disposal of artificial CO2 (CO2 sequestration) are discussed. The primary results of investigations and possible schemes for implementing the processes in pilot and commercial installations are presented. Their technical and economic indicators are estimated, and a possibility of disposing CO2 produced during electricity generation is considered.

  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. Fuel properties effect on the performance of a small high temperature rise combustor

    NASA Technical Reports Server (NTRS)

    Acosta, Waldo A.; Beckel, Stephen A.

    1989-01-01

    The performance of an advanced small high temperature rise combustor was experimentally determined at NASA-Lewis. The combustor was designed to meet the requirements of advanced high temperature, high pressure ratio turboshaft engines. The combustor featured an advanced fuel injector and an advanced segmented liner design. The full size combustor was evaluated at power conditions ranging from idle to maximum power. The effect of broad fuel properties was studied by evaluating the combustor with three different fuels. The fuels used were JP-5, a blend of Diesel Fuel Marine/Home Heating Oil, and a blend of Suntec C/Home Heating Oil. The fuel properties effect on the performance of the combustion in terms of pattern factor, liner temperatures, and exhaust emissions are documented.

  17. [Effects of fuel properties on the performance of a typical Euro IV diesel engine].

    PubMed

    Chen, Wen-miao; Wang, Jian-xin; Shuai, Shi-jin

    2008-09-01

    With the purpose of establishing diesel fuel standard for China National 4th Emission Standard, as one part of Beijing "Auto-Oil" programme, engine performance test has been done on a typical Euro IV diesel engine using eight diesel fuels with different fuel properties. Test results show that, fuel properties has little effect on power, fuel consumption, and in-cylinder combustion process of tested Euro IV diesel engine; sulfate in PM and gaseous SO2 emissions increase linearly with diesel sulfur content increase; cetane number increase cause BSFC and PM reduce and NOx increase; T90 decrease cause NOx reduce while PM shows trend of reduce. Prediction equations of tested Euro IV diesel engine's ESC cycle NOx and PM emissions before SCR response to diesel fuel sulfur content, cetane number, T90 and aromatics have been obtained using linear regression method on the base of test results. PMID:19068662

  18. Experimental Investigation of Fuel-Reactivity Controlled Compression Ignition (RCCI) Combustion Mode in a Multi-Cylinder, Light-Duty Diesel Engine

    SciTech Connect

    Cho, Kukwon; Curran, Scott; Prikhodko, Vitaly Y; Sluder, Scott; Parks, II, James E; Wagner, Robert M

    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.

  19. Combustion performance of bipropellant liquid rocket engine combustors with fuel-impingement cooling

    NASA Astrophysics Data System (ADS)

    Jiang, Tsung Leo; Chiang, Wei-Tang; Jang, Shyh-Dihng

    1995-05-01

    In order to obtain an accurate combustion analyses which are important in the thruster design of modern advanced liquid rocket engine, flow analysis should be conducted from the injector phase down to the propulsive nozzle throat. Thus, in the present study, flow analysis for the axisymmetric thrust chamber of an OMV(exp 3) installed with a pintle-type ring-shaped injector and a conical convergent nozzle is conducted. Liquid monomethyl hydrazine (MMH) and nitrogen tetroxide (NTO) storable bipropellants are used as fuel and oxidizer sources. An optimum injected fuel and oxidizer droplet-size combination is proposed. Finally, the results obtained are presented.

  20. 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.

  1. Corrosion prevention in hydrocarbon-fueled booster engine combustion chamber liners

    SciTech Connect

    Rosenberg, S.D.; Gage, M.L.

    1989-01-01

    Static and dynamic tests with methane fuels containing trace amounts of sulfur compounds were performed in order to identify and develop procedures to protect against the corrosive interaction process that occurs between the fuel and the copper combustion chamber liner materials in the coolant side of a regeneratively cooled hydrocarbon booster engine. Foils of gold, platinum, zirconium, iridium, niobium, and rehenium all displayed good resistance to sulfur corrosion at 700 F and 3000 psig. Gold and platinum coatings were shown to greatly reduce corrosion of the cooling channels in tests with methane containing 5 ppm CH3SH or 5 ppm H2S. 5 refs.

  2. Combustion performance of bipropellant liquid rocket engine combustors with fuel-impingement cooling

    SciTech Connect

    Jiang, T.L.; Chiang, W.; Jang, S.

    1995-05-01

    In order to obtain an accurate combustion analyses which are important in the thruster design of modern advanced liquid rocket engine, flow analysis should be conducted from the injector phase down to the propulsive nozzle throat. Thus, in the present study, flow analysis for the axisymmetric thrust chamber of an OMV(exp 3) installed with a pintle-type ring-shaped injector and a conical convergent nozzle is conducted. Liquid monomethyl hydrazine (MMH) and nitrogen tetroxide (NTO) storable bipropellants are used as fuel and oxidizer sources. An optimum injected fuel and oxidizer droplet-size combination is proposed. Finally, the results obtained are presented. 4 refs.

  3. Experimental investigation of fuel evaporation in the vaporizing elements of combustion chambers

    NASA Technical Reports Server (NTRS)

    Vezhba, I.

    1979-01-01

    A description is given of the experimental apparatus and the methods used in the investigation of the degree of fuel (kerosene) evaporation in two types of vaporizing elements in combustion chambers. The results are presented as dependences of the degree of fuel evaporation on the factors which characterize the functioning of the vaporizing elements: the air surplus coefficient, the velocity of flow and temperature of the air at the entrance to the vaporizing element and the temperature of the wall of the vaporizing element.

  4. Gas separation process using membranes with permeate sweep to remove CO.sub.2 from gaseous fuel combustion exhaust

    DOEpatents

    Wijmans Johannes G.; Merkel, Timothy C.; Baker, Richard W.

    2012-05-15

    A gas separation process for treating exhaust gases from the combustion of gaseous fuels, and gaseous fuel combustion processes including such gas separation. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, while simultaneously flowing a second portion of the exhaust gas stream across the feed side of a membrane, flowing a sweep gas stream, usually air, across the permeate side, then passing the permeate/sweep gas back to the combustor.

  5. Combustion and emissions characterization of pelletized coal fuels. [Quarterly] technical report, March 1--May 31, 1993

    SciTech Connect

    Rajan, S.

    1993-09-01

    Pelletization of coal offers a means of utilizing coal fines which otherwise would be difficult to use. Other advantages of coal pelletization include: (a) utilization of low grade fuels such as preparation plant waste, (b) impregnation of pellets with calcium carbonate or calcium hydroxide sorbent for efficient sulfur removal, and (c) utilization of coal fines of low quality in combination with different types of binders. The objective of this project is to investigate the carbon conversion efficiency and SO{sub 2} and NO{sub x} emissions from combusting pelletized coal fuels made from preparation plant waste streams using both limestone and calcium hydroxide as sorbent and cornstarch and gasification tar as binders. The combustion performance of these pelletized fuels is compared with equivalent data from a reference run-of-mine coal. Six different samples of coal pellets have been secured from ISGS researchers. Combustion and emissions characterization of these pellets in the laboratory scale 4-inch diameter circulating fluidized bed have been performed on some of the pellet samples. The pellets burn readily, and provide good bed temperature control. Preliminary results show good carbon conversion efficiencies. Oxides of nitrogen emissions are quite low and sulfur dioxide emissions are as good as or lower than those from a representative run-of-mine coal.

  6. Nanoscopic fuel-rich thermobaric formulations: Chemical composition optimization and sustained secondary combustion shock wave modulation.

    PubMed

    Mohamed, Ahmed K; Mostafa, Hosam E; Elbasuney, Sherif

    2016-01-15

    Advanced thermobaric explosives have become one of the urgent requirements when targeting caves, fortified structures, and bunkers. Highly metal-based systems are designed to exploit the secondary combustion resulted from active metal particles; thus sustained overpressure and additional thermal loadings can be achieved. This study, reports on a novel approach for chemical composition optimization using thermochemical calculations in an attempt to achieve the highest explosion power. Shock wave resulted from thermobaric explosives (TBX) was simulated using ANSYS(®) AUTODYN(®) 2D hydrocode. Nanoscopic fuel-rich thermobaric charge was prepared by pressing technique; static field test was conducted. Comparative studies of modeled pressure-time histories to practical measurements were conducted. Good agreement between numerical modeling and experimental measurements was observed, particularly in terms of the prediction of wider overpressure profile which is the main characteristics of TBX. The TBX wider overpressure profile was ascribed to the secondary shock wave resulted from fuel combustion. The shock wave duration time and its decay pattern were acceptably predicted. Effective lethal fire-ball duration up to 50ms was achieved and evaluated using image analysis technique. The extended fire-ball duration was correlated to the additional thermal loading due to active metal fuel combustion. The tailored thermobaric charge exhibited an increase in the total impulse by 40-45% compared with reference charge. PMID:26426986

  7. Health effects of residential wood smoke particles: the importance of combustion conditions and physicochemical particle properties

    PubMed Central

    Kocbach Bølling, 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

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

    SciTech Connect

    Szybist, James P

    2008-01-01

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

  9. 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 (μm2/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 μm2/cm3) compared to times without combustion (mean: 14.0 μm2/cm3). The observed levels during burning were reduced by about four-fold in homes with a chimney (mean: 92.1 μm2/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

  10. 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.

  11. 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.

  12. 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

  13. Identification and quantification analysis of nonlinear dynamics properties of combustion instability in a diesel engine

    SciTech Connect

    Yang, Li-Ping Ding, Shun-Liang; Song, En-Zhe; Ma, Xiu-Zhen; Litak, Grzegorz

    2015-01-15

    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.

  14. Measurement of fuel mixing and transport processes in gas turbine combustion

    NASA Astrophysics Data System (ADS)

    McDonell, V. G.; Samuelsen, G. S.

    2000-07-01

    The measurement techniques for delineating fuel-air mixing and transport in gas turbine combustion, as well as examples of representative results, are provided in this overview. The summary is broken into applications for gaseous fuels and liquid fuels since many diagnostics which are specific to the phase of the fuel have been developed. Many possible methods for assessing the general mixing have been developed, but not all have been applied to practical systems either under scaled or under actual conditions. With respect to gaseous mixing processes, planar laser-induced fluorescence (PLIF) based on acetone is now starting to be successfully applied to actual systems and conditions. In spray-fired systems, the need to discriminate between phases leads to considerable complication in delineating fuel-air mixing. Methods that focus on the discrete phase have successfully provided details relative to the droplets. These include phase Doppler interferometry (PDI), which is becoming ubiquitous in application to practical devices and under practical conditions. PDI is typically being applied to quantify droplet sizes, although the volume flux, which is relevant to fuel-air mixing, in practical systems is also being reported. In addition, PLIF strategies that focus upon the behaviour of the droplets are now being developed. However, PLIF strategies that can discriminate between phases either in the fuel or with respect to the liquid fuel and combustion air are also being developed. In terms of characterizing the vector fields associated with the mixing process, laser anemometry (LA), although it is tedious to apply, has proven reliable even in the presence of droplets. Newer methods such as DPIV and FRS have seen only limited application in practical systems but appear promising. In terms of scalar fields, LIF and PLIF have also been applied successfully to these systems, and examples of the measurements of concentrations of various radical species such as OH are found throughout the literature.

  15. Determination of Combustion Product Radicals in a Hydrocarbon Fueled Rocket Exhaust Plume

    NASA Technical Reports Server (NTRS)

    Langford, Lester A.; Allgood, Daniel C.; Junell, Justin C.

    2007-01-01

    The identification of metallic effluent materials in a rocket engine exhaust plume indicates the health of the engine. Since 1989, emission spectroscopy of the plume of the Space Shuttle Main Engine (SSME) has been used for ground testing at NASA's Stennis Space Center (SSC). This technique allows the identification and quantification of alloys from the metallic elements observed in the plume. With the prospect of hydrocarbon-fueled rocket engines, such as Rocket Propellant 1 (RP-1) or methane (CH4) fueled engines being considered for use in future space flight systems, the contributions of intermediate or final combustion products resulting from the hydrocarbon fuels are of great interest. The effect of several diatomic molecular radicals, such as Carbon Dioxide , Carbon Monoxide, Molecular Carbon, Methylene Radical, Cyanide or Cyano Radical, and Nitric Oxide, needs to be identified and the effects of their band systems on the spectral region from 300 nm to 850 nm determined. Hydrocarbon-fueled rocket engines will play a prominent role in future space exploration programs. Although hydrogen fuel provides for higher engine performance, hydrocarbon fuels are denser, safer to handle, and less costly. For hydrocarbon-fueled engines using RP-1 or CH4 , the plume is different from a hydrogen fueled engine due to the presence of several other species, such as CO2, C2, CO, CH, CN, and NO, in the exhaust plume, in addition to the standard H2O and OH. These species occur as intermediate or final combustion products or as a result of mixing of the hot plume with the atmosphere. Exhaust plume emission spectroscopy has emerged as a comprehensive non-intrusive sensing technology which can be applied to a wide variety of engine performance conditions with a high degree of sensitivity and specificity. Stennis Space Center researchers have been in the forefront of advancing experimental techniques and developing theoretical approaches in order to bring this technology to a more mature stage.

  16. 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.

  17. Fluorescence characteristics of the fuel tracers triethylamine and trimethylamine for the investigation of fuel distribution in internal combustion engines.

    PubMed

    Lind, Susanne; Aßmann, Simon; Zigan, Lars; Will, Stefan

    2016-03-01

    Laser-induced fluorescence based on fuel tracers like amines is a suitable measurement technique for mixing studies in internal combustion (IC) engines. Triethylamine has often been used in gasoline IC engines; however, no detailed fluorescence characterization for excitation at 263 or 266 nm is available. Trimethylamine (TMA) exhibits high potential as a gaseous fuel tracer but little information about TMA fluorescence is currently available. A picosecond laser source combined with a streak camera equipped with a spectrograph was used to determine the spectral fluorescence emission and fluorescence decay time of both tracers. The tracers were investigated at various temperatures and pressures in a calibration cell with nitrogen as bath gas. The results provide an in-depth understanding of the fluorescence characteristics of both tracers and allow assessment of their application to the investigation of fuel distribution in IC engines. PMID:26974612

  18. 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.

  19. 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

  20. Greenhouse impact due to the use of combustible fuels: life cycle viewpoint and relative radiative forcing commitment.

    PubMed

    Kirkinen, Johanna; Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

    2008-09-01

    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