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1

Properties of air and combustion products of fuel with air  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

2

Aviation-fuel property effects on combustion  

NASA Technical Reports Server (NTRS)

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.

Rosfjord, T. J.

1984-01-01

3

Predicting combustion properties of hydrocarbon fuel mixtures  

E-print Network

In this thesis, I applied computational quantum chemistry to improve the accuracy of kinetic mechanisms that are used to model combustion chemistry. I performed transition state theory calculations for several reactions ...

Goldsmith, Claude Franklin, III

2010-01-01

4

Fuel property effects on engine combustion processes. Final report  

SciTech Connect

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

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

1995-04-27

5

The Effect of Air\\/Fuel Ratio on Properties and Reactivity of Combustion Soots  

Microsoft Academic Search

The dependence of specific properties of black carbon (BC) soots on fuel type and combustion conditions has been studied, and the effects of these properties on soot particle hydration and reaction with ozone determined. Series of soots were prepared from n-hexane, diesel and JP8 aircraft fuels, utilizing a flow combustion system designed for accurate control of the air\\/fuel ratio in

A. R. Chughtai; J. M. Kim; D. M. Smith

2002-01-01

6

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

SciTech Connect

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

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

2007-01-01

7

Effect of W/O Emulsion Fuel Properties on Spray Combustion  

NASA Astrophysics Data System (ADS)

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

Ida, Tamio; Fuchihata, Manabu; Takeda, Shuuco

8

Combustion properties of biomass  

Microsoft Academic Search

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

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

1998-01-01

9

Properties of air and combustion products of fuels with air  

NASA Technical Reports Server (NTRS)

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

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

1969-01-01

10

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

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

11

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

Microsoft Academic Search

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

James P Szybist; Kalyana Chakravathy; C Stuart Daw

2012-01-01

12

Characteristics and combustion of future hydrocarbon fuels  

NASA Technical Reports Server (NTRS)

Changes in fuel properties that are expected in future hydrocarbon fuels for aircraft are discussed along with the principal properties of 'syncrudes' and the fuels that can be derived from them. 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.

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

1978-01-01

13

Effect of fuel ratio on combustion synthesis and properties of magnetic nanostructures  

NASA Astrophysics Data System (ADS)

We report a simple one-step solution combustion method for the preparation of ultrafine Ni, NiO and Ni/NiO nanostructures. The fuel-to-oxidizer ratio can be tuned to control the formation of either nanoparticles (Ni or NiO) or nanocomposites (Ni/NiO). The resultant nanostructures are characterized by x-ray diffraction, scanning electron microscopy, Raman spectroscopy and vibrating sample magnetometer. Processing under fuel rich conditions leads to the formation of Ni/NiO nanocomposite while fuel lean environment results in primarily NiO. The processing conditions influence the stoichiometry and the size (6.8 to 39.5 nm) of NiO nanoparticles. The intensity of one- phonon Raman longitudinal optical mode is found to be higher than two-phonon optical mode for non-stoichiometric NiO. The saturation magnetization and coercivity of the as-synthesized powders are influenced by the ratio of Ni to NiO, stoichiometry of NiO and pore size.

Arunkumar, P.; Aadhavan, R.; Bhanuchandar, S.; Babu, K. Suresh

2014-09-01

14

Fuel quality combustion analysis  

NASA Technical Reports Server (NTRS)

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.

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

1979-01-01

15

Method of combustion for dual fuel engine  

DOEpatents

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.

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

1993-12-21

16

Method of combustion for dual fuel engine  

DOEpatents

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.

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

1993-12-21

17

Combustor nozzle for a fuel-flexible combustion system  

DOEpatents

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.

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

2011-03-22

18

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)

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.

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

1978-01-01

19

Catalytic combustion of residual fuels  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

20

Risk factors of jet fuel combustion products.  

PubMed

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

Tesseraux, Irene

2004-04-01

21

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

Microsoft Academic Search

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

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

2011-01-01

22

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)

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.)

Rozelle, Peter Lawrence

2000-10-01

23

Fuel effects on gas turbine combustion-ignition, stability, and combustion efficiency  

SciTech Connect

An analytical study is made of the substantial body of experimental data acquired during recent Wright-Patterson Aero Propulsion Laboratory sponsored programs on the effects of fuel properties on the performance and reliability of several gas turbine combustors, including J79-17A, J79-17C (Smokeless), F101, TF41, TF39, J85, TF33, and F100. Quantitative relationships are derived between certain key aspects of combustion, notably combustion efficiency, lean blowout limits and lean light-off limits, and the relevant fuel properties, combustor design features, and combustor operating conditions. It is concluded that combustion efficiency, lean blowout limits, and lean lightoff limits are only slightly dependent on fuel chemistry, but are strongly influenced by the physical fuel properties that govern atomization quality and spray evaporation rates.

Lefebvre, A.H.

1984-06-01

24

Fuel effects on gas turbine combustion-ignition, stability, and combustion efficiency  

SciTech Connect

An analytical study is made of the substantial body of experimental data acquired during recent Wright-Patterson Aero Propulsion Laboratory sponsored programs on the effects of fuel properties on the performance and reliability of several gas turbine combustors, including J79-17A, J79-17C (Smokeless), F101, TF41, TF39, J85, TF33, and F100. Quantitative relationships are derived between certain key aspects of combustion, notably combustion efficiency, lean blowout limits and lean light-off limits, and the relevant fuel properties, combustor design features, and combustor operating conditions. It is concluded that combustion efficiency, lean blowout limits, and lean lightoff limits are only slightly dependent on fuel chemistry, but are strongly influenced by the physical fuel properties that govern atomization quality and spray evaporation rates.

Lefebvre, A.H.

1985-01-01

25

Combustion and fuel characterization of coal-water fuels  

SciTech Connect

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.

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

1987-06-01

26

Oscillating combustion from a premix fuel nozzle  

SciTech Connect

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.

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

1995-08-01

27

30 CFR 77.1105 - Internal combustion engines; fueling.  

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

2014-07-01

28

30 CFR 56.4103 - Fueling internal combustion engines.  

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

2014-07-01

29

30 CFR 57.4103 - Fueling internal combustion engines.  

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

2014-07-01

30

Fuel Interchangeability Considerations for Gas Turbine Combustion  

SciTech Connect

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.

Ferguson, D.H.

2007-10-01

31

Engine combustion control via fuel reactivity stratification  

DOEpatents

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).

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

2013-12-31

32

Characteristics and combustion of future hydrocarbon fuels. [aircraft fuels  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

33

Survey of Hydrogen Combustion Properties  

NASA Technical Reports Server (NTRS)

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.

Drell, Isadore L; Belles, Frank E

1958-01-01

34

Combustion characteristics of gas turbine alternative fuels  

NASA Technical Reports Server (NTRS)

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.

Rollbuhler, R. James

1987-01-01

35

Fuel injector for an internal combustion engine  

Microsoft Academic Search

A fuel injector is described for an internal combustion engine, which comprises: a body having an axial bore; a normally closed injection nozzle mounted to the body in alignment with the bore, the injection nozzle being of the differential pressure type including a pressure chamber and a needle valve; injection fuel supply means in the body for supplying a high

T. Yoshinaga; T. Igashira; Y. Sakakibara; Y. Natsuyama

1986-01-01

36

Fundamental Combustion Studies of Emulsified Fuels. Annual Progress Report, October 1, 1979-September 30, 1980.  

National Technical Information Service (NTIS)

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 phenomen...

I. M. Kennedy

1980-01-01

37

Combustion of liquid fuels in a flowing combustion gas environment at high pressures  

NASA Technical Reports Server (NTRS)

The combustion of fuel droplets in gases which simulate combustion chamber conditions was considered both experimentally and theoretically. The fuel droplets were simulated by porous spheres and allowed to gasify in combustion gases produced by a burner. Tests were conducted for pressures of 1-40 atm, temperatures of 600-1500 K, oxygen concentrations of 0-13% (molar) and approach Reynolds numbers of 40-680. The fuels considered in the tests included methanol, ethanol, propanol-1, n-pentane, n-heptane and n-decane. Measurements were made of both the rate of gasification of the droplet and the liquid surface temperature. Measurements were compared with theory, involving various models of gas phase transport properties with a multiplicative correction for the effect of forced convection.

Canada, G. S.; Faeth, G. M.

1975-01-01

38

NASA broad-specification fuels combustion technology program  

NASA Technical Reports Server (NTRS)

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.

Fear, J. S.

1984-01-01

39

Combustion and fuel characterization of coal-water fuels  

SciTech Connect

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.

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

1989-02-01

40

Internal combustion engine fuel rail assembly joint  

SciTech Connect

This patent describes a fuel rail assembly of an internal combustion engine. It comprises a non-metallic fuel rail containing devices that are part of a fuel injection system of the engine, and also comprising a metal tube which is in fluid communication with a fuel passage in the non-metallic fuel rail and connected with the non-metallic fuel rail by means of a joint, characterized in that the joint comprises a cylindrical metal sleeve that is partially embedded in the non-metallic fuel rail such that a first cylindrical portion of the non-metallic fuel rail lines an interior end portion of the sleeve and is in fluid communication with the fuel passage in the non-metallic fuel rail and such that the sleeve lines the interior of a second cylindrical portion of the non-metallic fuel rail, the metal tube and the first cylindrical portion of the non-metallic fuel rail fit together in a sealed manner to place the metal tube in fluid communication with the fuel passage in the non-metallic fuel rail, the sleeve has another portion that is not embedded in the non-metallic fuel rail, and a retention means coacts with the another axis end segment and with the metal tube to retain the metal tube and the first cylindrical portion of the non-metallic fuel rail fit together in a sealed manner.

Imoehl, W.J.

1992-04-21

41

Hybrid combustion with metallized fuels  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

42

Catalytic combustion with incompletely vaporized residual fuel  

NASA Technical Reports Server (NTRS)

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.

Rosfjord, T. J.

1981-01-01

43

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

SciTech Connect

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.

Venkatesan, Krishna

2011-11-30

44

Studies of oscillatory combustion and fuel vaporization  

NASA Technical Reports Server (NTRS)

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.

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

1972-01-01

45

Numerical modeling of hydrogen-fueled internal combustion engines  

SciTech Connect

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.

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

1996-12-31

46

Combustion oscillation control by cyclic fuel injection  

SciTech Connect

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.

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

1995-04-01

47

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

SciTech Connect

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.

Hiromi Shirai; Hirofumi Tsuji; Michitaka Ikeda; Toshinobu Kotsuji [Central Research Institute of Electric Power Industry, Kanagawa (Japan)

2009-07-15

48

Fundamental Combustion Studies of Emulsified Fuels. Final Report.  

National Technical Information Service (NTIS)

An experimental apparatus was designed and built in order to study the combustion of free, isolated fuel droplets at low Reynolds number conditions. Studies were conducted into the disruptive combustion behavior of n-paraffin/water emulsions and binary so...

F. L. Dryer

1982-01-01

49

Sensitivity of dual fuel engine combustion and knocking limits to gaseous fuel composition  

Microsoft Academic Search

Combustion noise, knock and ignition limits data are measured and presented for a dual fuel engine running on dual fuels of Diesel and three gaseous fuels separately. The gaseous fuels used are liquefied petroleum gas, pure methane and compressed natural gas mixture. The maximum pressure rise rate during combustion is presented as a measure of combustion noise, and the knocking

Mohamed Y. E. Selim

2004-01-01

50

Demonstration of catalytic combustion with residual fuel  

NASA Technical Reports Server (NTRS)

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.

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

1981-01-01

51

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

DOEpatents

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.

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

2013-12-17

52

Combustion characterization of beneficiated coal-based fuels  

SciTech Connect

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.

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

1990-08-01

53

Devolatilisation behaviour of petroleum coke under pulverised fuel combustion conditions  

Microsoft Academic Search

The combustion of petroleum coke in large scale facilities has been limited due to its high sulphur content, but the increasing installation of flue-gas desulphurisation units makes possible the firing of petroleum coke either as a primary fuel or blended with coals. This study focuses on the behaviour of three fuel-grade petroleum cokes of different provenance under pulverised fuel combustion

K. S Milenkova; A. G Borrego; D Alvarez; J Xiberta; R Menéndez

2003-01-01

54

Introduction Fossil fuel combustion by aviation, shipping and road  

E-print Network

96 Introduction Fossil fuel combustion by aviation, shipping and road traffic contributes about one. here we summarize some of the first findings. Emissions by transport modes Emissions from fossil fuel to global CO emissions are estimated to be much smaller, likely due to more efficient fuel combustion. Road

Haak, Hein

55

Hydrogen-fueled internal combustion engines.  

SciTech Connect

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.

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

2009-12-01

56

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

SciTech Connect

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.

Chia-fon F. Lee; Alan C. Hansen

2010-09-30

57

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

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

58

Broad specification fuels combustion technology program, phase 2. Final report  

SciTech Connect

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.

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

1990-10-01

59

Broad Specification Fuels Combustion Technology Program, Phase 2  

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

60

Design handbook for gaseous fuel engine injectors and combustion chambers  

NASA Technical Reports Server (NTRS)

Results of investigation of injection, mixing, and combustion processes using gaseous fuels and oxidizers have been summarized in handbook presenting succinct design procedures for injectors and methods for estimating combustion efficiency, chamber heat flux and stability characteristics. Handbook presents two approaches to injector and combustion chamber design: empirical and analytical.

Calhoon, D. F.; Ito, I.; Kors, D. L.

1973-01-01

61

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

Microsoft Academic Search

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,

Turchan

1990-01-01

62

Fuel NOx production during the combustion of low caloric value fuel  

SciTech Connect

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.

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

1997-07-01

63

Combustion characteristics of alternative liquid fuels  

E-print Network

-mechanism ………………………………………………………….. 30 2.2 Comparison of fuel properties ………………………………………………….. 37 CHAPTER 3 3.1 Percentage of fatty acids composition of different vegetable oils …… 60 3.2 Chemical structure of common fatty acids and their methyl esters .. 60 3... or cellulose need to undergo hydrolysis to convert the carbohydrates into sugar prior to microbial fermentation. Water is removed from the fermented fuels through distillation process to obtain bioethanol. Bioethanol contains characteristics close to light...

Chong, Cheng Tung

2011-11-08

64

Combustion Characteristics of Liquid Normal Alkane Fuels in a Model Combustor of Supersonic Combustion Ramjet Engine  

NASA Astrophysics Data System (ADS)

Effect of kinds of one-component n-alkane liquid fuels on combustion characteristics was investigated experimentally using a model combustor of scramjet engine. The inlet condition of a model combustor is 2.0 of Mach number, up to 2400K of total temperature, and 0.38MPa of total pressure. Five kinds of n-alkane are tested, of which carbon numbers are 7, 8, 10, 13, and 16. They are more chemically active and less volatile with an increase of alkane carbon number. Fuels are injected to the combustor in the upstream of cavity with barbotage nitrogen gas and self-ignition performance was investigated. The result shows that self-ignition occurs with less equivalence ratio when alkane carbon number is smaller. This indicates that physical characteristic of fuel, namely volatile of fuel, is dominant for self-ignition behavior. Effect on flame-holding performance is also examined with adding pilot hydrogen and combustion is kept after cutting off pilot hydrogen with the least equivalence ratio where alkane carbon number is from 8 to 10. These points are discussed qualitatively from the conflict effect of chemical and physical properties on alkane carbon number.

??, ?; ??, ??; ??, ??; ??, ???; ??, ??; ??, ??; ??, ??

65

Fossil Fuel Combustion and the Major Sedimentary Cycle  

Microsoft Academic Search

The combustion of the fossil fuels coal, oil, and lignite potentially can mobilize many elements into the atmosphere at rates, in general, less than but comparable to their rates of flow through natural waters during the weathering cycle. Since the principal sites of fossil fuel combustion are in the mid-latitudes of the Northern Hemisphere, changes in the composition of natural

K. K. Bertine; Edward D. Goldberg

1971-01-01

66

Basic Considerations in the Combustion of Hydrocarbon Fuels with Air  

NASA Technical Reports Server (NTRS)

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.

Barnett, Henry C; Hibbard, Robert R

1957-01-01

67

Fuel dispenser for internal combustion engine  

SciTech Connect

A fuel dispensing device is described used in an internal combustion engine which consists of: throttle valve means; a sensor for detecting an operational state of the engine; a control circuit which produces an engine control signal based on the output of the sensor; an even number of intake tubes connected to an intake passage on the downstream side of the throttle valve means, with each of the tubes branching at the downstream end thereof into two parts that are connected to two cylinders of the engine; at least one atomizer provided for at least a pair of the intake tubes, the atomizer comprising a pair of cylindrical atomizer rings disposed in the intake tube pair and a driver for driving the atomizer ring pair in response to the control signal from the control circuit; and an even number of injection valves each provided for each of the atomizer rings so as to inject fuel onto the interior wall of the atomizer ring through a hole formed in the wall of the atomizer ring, so that the fuel is atomized by the vibration of the atomizer rings, while intermixing with air, and delivered to respective cylinders.

Yamauchi, T.; Nogi, T.; Oyama, Y.

1986-03-18

68

Oxy-combustion of high water content fuels  

NASA Astrophysics Data System (ADS)

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

Yi, Fei

69

The Quality Control of Combustible Fuels in Albania  

Microsoft Academic Search

After the '90s, the Albanian Economy felt in the stagnation. Despite that fact the market demands for oil's by-products like: fuels, lubricants, combustible fuels and liquid pressure gas (L.P.G), is grown continuously. Combustible liquid fossil fuels serve like energy sources not only in the Industry and Agriculture, but also for residential services. Statistical data show that usage of the oil

Ismet Beqiraj; Spiro Drushku; Agim Maja; Hasime Manaj

2010-01-01

70

Combustion and fuel characterization of coal-water fuels  

SciTech Connect

Pittsburgh Energy Technology Center (PETC) of the Department of Energy initiated a comprehensive effort in 1982 to develop the necessary performance and cost data and to assess the commercial viability of coal water fuels (CWFs) as applied to representative utility and industrial units. The effort comprised six tasks beginning with coal resource evaluation and culminating in the assessment of the technical and economic consequences of switching representative commercial units from oil to state-of-the-art CWF firing. Extensive bench, pilot and commercial-scale tests were performed to develop necessary CWF combustion and fireside performance data for the subsequent boiler performance analyses and retrofit cost estimates. This report (Volume 2) provides a review of the fuel selection and procurement activities. Included is a discussion on coal washability, transport of the slurry, and characterization. 20 figs., 26 tabs.

Not Available

1989-07-01

71

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

NASA Astrophysics Data System (ADS)

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

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

2013-06-01

72

Emissions from the laboratory combustion of wildland fuels: Particle morphology and size  

Microsoft Academic Search

The morphology of particles emitted by wildland fires contributes to their physical and chemical properties but is rarely determined. As part of a study at the USFS Fire Sciences Laboratory (FSL) investigating properties of particulate matter emitted by fires, we studied the size, morphology, and microstructure of particles emitted from the combustion of eight different wildland fuels (i.e., sagebrush, poplar

Rajan K. Chakrabarty; Hans Moosmüller; Mark A. Garro; W. Patrick Arnott; John Walker; Ronald A. Susott; Ronald E. Babbitt; Cyle E. Wold; Emily N. Lincoln; Wei Min Hao

2006-01-01

73

Broad specification fuels combustion technology program  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

74

Combustion Properties of Biomass Flash Pyrolysis Oils: Final Project Report  

SciTech Connect

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.

C. R. Shaddix; D. R. Hardesty

1999-04-01

75

Solid fuel combustion system for gas turbine engine  

DOEpatents

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.

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

1993-01-01

76

A Nonlinear Model for Fuel Atomization in Spray Combustion  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

77

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

E-print Network

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

Shroll, Andrew Philip

2011-01-01

78

Method of reducing the sulfur oxide content of combustion gases resulting from combustion of sulfur-containing fossil fuels  

Microsoft Academic Search

Sulfur-containing fossil fuels are combusted in the presence of calcium carbonate or calcium magnesium carbonate, whereby the sulfur oxides formed by combustion react with the calcium oxide or calcium magnesium formed from the carbonate during the combustion, thereby to form calcium sulfate or calcium magnesium sulfate. The sulfur oxide content of the combustion gas is thereby reduced. The calcium oxide

Rechmeier

1980-01-01

79

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...

80

Fundamentals of nitric oxide formation in fossil fuel combustion  

Microsoft Academic Search

Combustion of fossil fuels in large stationary furnaces causes the emission of nitrogen oxides, a large fraction of which arise from the nitrogen-containing components in the fuel, producing a major pollution problem which is expected to increase severely in the future. The results reported in this paper are part of those obtained from a continuing study to determine the mechanism

T. J. Houser; M. E. McCarville; G. Zhou-Ying

1986-01-01

81

Adaptive air\\/fuel ratio controller for internal combustion engine  

Microsoft Academic Search

An air\\/fuel ratio controller for an internal combustion engine including two memories each having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air\\/fuel ratio. Each memory location in the first memory is

A. F. Chiesa; D. G. Evans; J. R. Norford; J. A. Zahorchak

1982-01-01

82

Superheated fuel injection for combustion of liquid-solid slurries  

DOEpatents

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.

Robben, Franklin A. (Berkeley, CA)

1985-01-01

83

Superheated fuel injection for combustion of liquid-solid slurries  

DOEpatents

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.

Robben, F.A.

1984-10-19

84

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

Microsoft Academic Search

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

Sridhar Venkatabojji Machiroutu

2001-01-01

85

Combustion fundamentals of pyrolysis oil based fuels  

SciTech Connect

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)

Calabria, R.; Chiariello, F.; Massoli, P. [Istituto Motori CNR, Via Marconi 8, 80125 Napoli (Italy)

2007-04-15

86

Oxy-fuel combustion with integrated pollution control  

DOEpatents

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.

Patrick, Brian R. (Chicago, IL); Ochs, Thomas Lilburn (Albany, OR); Summers, Cathy Ann (Albany, OR); Oryshchyn, Danylo B. (Philomath, OR); Turner, Paul Chandler (Independence, OR)

2012-01-03

87

Combustion of solid fuel in very low speed oxygen streams  

NASA Technical Reports Server (NTRS)

In reduced gravity, the combustion of solid fuel in low-speed flow can be studied. The flame behavior in this low-speed regime will fill a void in our understanding of the flow effect on combustion. In addition, it is important for spacecraft fire safety considerations. In this work, modeling and experimental work on low-speed forced-concurrent-flow flame spread are carried out. In addition, experiments on reduced-gravity buoyant-flow flame spread are performed.

Tien, James S.; Sacksteder, Kurt R.; Ferkul, Paul V.; Grayson, Gary D.

1993-01-01

88

Alternate-Fueled Combustion-Sector Emissions  

NASA Technical Reports Server (NTRS)

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.

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

89

Straw pellets as fuel in biomass combustion units  

SciTech Connect

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.

Andreasen, P.; Larsen, M.G. [Danish Technological Inst., Aarhus (Denmark)

1996-12-31

90

Effects of ambient conditions and fuel composition on combustion stability  

SciTech Connect

Recent regulations on NO, emissions are promoting the use of lean premix (LPM) combustion for industrial gas turbines. LPM combustors avoid locally stoichiometric combustion by premixing fuel and the air upstream of the reaction region, thereby eliminating the high temperatures that produce thermal NO.. Unfortunately, this style of combustor is prone to combustion oscillation. Significant pressure fluctuations can occur when variations in heat release periodically couple pressure to acoustic modes in the combustion chamber. These oscillations must be controlled because resulting vibration can shorten the life of engine hardware. Laboratory and engine field testing have shown that instability regimes can vary with environmental conditions. These observations prompted this study of the effects of ambient conditions and fuel composition on combustion stability. Tests are conducted on a sub-scale combustor burning natural gas, propane, and some hydrogen/hydrocarbon mixtures. A premix, swirl-stabilized fuel nozzle typical of industrial gas turbines is used. Experimental and numerical results describe how stability regions may shift as inlet air temperature, humidity, and fuel composition are altered. Results appear to indicate that shifting instability instability regimes are primarily caused by changes in reaction rate.

Janus, M.C.; Richards, G.A.; Yip, M.J. [USDOE Federal Energy Technology Center, Morgantown, WV (United States); Robey, E.H. [EG& G Technical Services of West Virginia (United States)

1997-04-01

91

Atomization and combustion properties of flashing injectors  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

92

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

SciTech Connect

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.

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

1993-03-01

93

Fuel conservation system for internal combustion engines  

Microsoft Academic Search

A system is provided for varying the number of active cylinders in a multi-cylinder internal combustion engine, in response to the operating requirements of the engine. When the engine reaches that part of its operating range where the torque requirement is such that operation of all of the cylinders is not required to provide adequate and efficient power, certain cylinders

1980-01-01

94

Combustion in a Bomb with a Fuel-Injection System  

NASA Technical Reports Server (NTRS)

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.

Cohn, Mildred; Spencer, Robert C

1935-01-01

95

Liquid fuel combustion within silicon-carbide coated carbon foam  

SciTech Connect

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

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

2007-10-15

96

Solid Surface Combustion Experiment: Thick Fuel Results  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

97

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

SciTech Connect

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

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

1996-12-31

98

Characterization of fuels for atmospheric fluidized bed combustion  

SciTech Connect

The Electric Power Research Institute (EPRI) has sponsored a fuels characterization program for the past several years with the intention of assisting utilities and boiler manufacturers in evaluating fuel quality impact on atmospheric fluidized bed combustion (AFBC) performance. The goal has been to provide an improved framework for making fuel switching decisions and consolidating operating experience. Results from this program include a set of bench-scale testing procedures, a fuel characterization data base, and a performance simulation model that links fuel characteristics to combustion performance. This paper reviews the major results of the fuels characterization program. The testing procedures, data base, and performance simulation models are briefly described and their application illustrated with examples. Performance predictions for the B W 1-ft{sup 2} bench-scale AFBC and the Tennessee Valley Authority (TVA) 20 MW(e) AFBC Pilot Plant are compared with actual test data. The relationship of coal rank to combustion is discussed. 11 refs., 12 figs., 5 tabs.

Daw, C.S. (Oak Ridge National Lab., TN (USA)); Rowley, D.R.; Perna, M.A. (Babcock and Wilcox Co., Alliance, OH (USA). Research Center); Stallings, J.W. (Electric Power Research Inst., Palo Alto, CA (USA)); Divilio, R.J. (Combustion Systems, Inc., Silver Spring, MD (USA))

1990-01-01

99

Combustion of refuse-derived fuel in a fluidised bed  

Microsoft Academic Search

As a medium to maximise the resources recovery from municipal solid waste, refuse-derived fuel (RDF) is considered as a priority solution in industrialised countries. RDF is a value added material with a higher calorific value and a homogeneous particle size. The main objective of this study was to investigate the RDF combustion characteristics and the associated pollutant emissions in a

Francisco D. Hernandez-Atonal; Changkook Ryu; Vida N. Sharifi; Jim Swithenbank

2007-01-01

100

Fuel reforming for scramjet thermal management and combustion optimization  

E-print Network

of the main issues of hypersonic flight is the thermal management of the overall vehicle and more specificallyFuel reforming for scramjet thermal management and combustion optimization E. DANIAU* , M. BOUCHEZ, Explosion, Structure - 63, nue de Lattre de Tassigny - 18020 Bourges Cedex It is common knowledge that one

Paris-Sud XI, Université de

101

Characterization of high velocity oxy-fuel combustion sprayed hydroxyapatite  

Microsoft Academic Search

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

Jeannie D. Haman; Linda C. Lucas; Daryl Crawmer

1995-01-01

102

Sedimentary records of carbonaceous particles from fossil fuel combustion  

Microsoft Academic Search

Carbonaceous particles produced by fossil fuel combustion can be found in considerable amounts in recent lake sediments. As these particles contain elemental carbon they are resistant to chemical decomposition and therefore both well preserved in sediments and possible to quantify. Sediment samples can be oxidized with H2O2 and digested with HF without the particles being destroyed. The pioneers in studying

Maria Wik; Ingemar Renberg; Judi Darley

1986-01-01

103

Fireside Corrosion in Oxy-Fuel Combustion of Coal  

SciTech Connect

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. 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.

Holcomb, Gordon R.; Tylczak, Joseph; Meier, G.H.; Jung. K.; Mu, N.; Yanar, N.M.; Pettit, F.S.

2012-08-01

104

Co-combustion: Burning biomass, fossil fuels together simplifies waste disposal, cuts fuel cost  

Microsoft Academic Search

Getting energy from biomass has introduced a new dimension in combustion systems. This report explores the state of the art of multifuel combustion, describes how existing firing systems can be optimized or refined for disparate fuels, outlines new firing systems-fluidized-bed combustors and gasifiers-that can be applied as well.

Makansi

1987-01-01

105

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

E-print Network

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

Vittilapuram Subramanian, Kannan

2006-04-12

106

Investigation of trapped vortex combustion using hydrogen-rich fuels  

NASA Astrophysics Data System (ADS)

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

Zbeeb, Khaled

107

Pressure Effects in Droplet Combustion of Miscible Binary Fuels  

NASA Technical Reports Server (NTRS)

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.

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

1997-01-01

108

Combustion characteristics of hydrogen-carbon monoxide based gaseous fuels  

NASA Technical Reports Server (NTRS)

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.

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

1982-01-01

109

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

SciTech Connect

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.

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

2009-01-01

110

Numerical analysis of supersonic combustion ramjet with upstream fuel injection  

NASA Astrophysics Data System (ADS)

This paper describes possible fuel injection scheme for airbreathing engines that use hydrocarbon fuels. The basic idea is to inject fuel at the spike tip of the supersonic inlet to achieve mixing and combustion efficiency with a limited length combustion chamber. A numerical code, able to solve the full Navier-Stokes equations in turbulent and reacting flows, is employed to obtain numerical simulations of the thermo-fluidynamic fields at different scramjet flight conditions, at Mach numbers of M=6.5 and 8. The feasibility of the idea of the upstream injection is checked for a simple axisymmetric configuration and relatively small size. The results are discussed in connection with the potential benefits deriving from the use of new ultra high temperature ceramics (UHTC).

Savino, Raffaele; Pezzella, Giuseppe

2003-09-01

111

Municipal solid waste combustion: Fuel testing and characterization  

SciTech Connect

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.

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

1990-10-01

112

Elimination of abnormal combustion in a hydrogen-fueled engine  

SciTech Connect

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.

Swain, M.R.; Swain, M.N. [Analytical Technologies, Inc., Miami, FL (United States)

1995-11-01

113

Numerical modeling of hydrogen-fueled internal combustion engines  

SciTech Connect

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.

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

1996-07-01

114

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

NASA Technical Reports Server (NTRS)

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.

Fear, J. S.

1983-01-01

115

Fuel injector nozzle for an internal combustion engine  

SciTech Connect

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.

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

2011-03-22

116

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

NASA Astrophysics Data System (ADS)

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.

Hofgren, Henrik; Sundén, Bengt

2014-09-01

117

Electrostatic fuel conditioning of internal combustion engines  

NASA Technical Reports Server (NTRS)

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.

Gold, P. I.

1982-01-01

118

Combustion chemistry and an evolving transportation fuel environment.  

SciTech Connect

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

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

2010-05-01

119

Combustion Of Poultry-Derived Fuel in a CFBC  

NASA Astrophysics Data System (ADS)

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.

Jia, Lufei; Anthony, Edward J.

120

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

PubMed

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

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

2014-06-01

121

Identification of combustion losses and air flow control in power plants burning inhomogeneous fuels  

Microsoft Academic Search

Combustion air flow control has a strong effect on the efficiency of a power plant. When using homogeneous fuels such as oil and natural gas the control can be based on an assumption that certain volumetric or mass flow of the fuel needs always a certain air flow for complete combustion. But with inhomogeneous fuels and in multi-fuel boilers this

Kari Lehtomäki; Reijo Ramu

122

Fuel-Air Mixing and Combustion in Scramjets. Chapter 6  

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

123

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

USGS Publications Warehouse

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.

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

1990-01-01

124

Santilli's new fuels as sources of clean combustion  

NASA Astrophysics Data System (ADS)

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.

Sarma, Indrani B. Das

2013-10-01

125

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

Microsoft Academic Search

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

Bruce G Bunting; Michael Bunce

2012-01-01

126

Combustion  

NASA Technical Reports Server (NTRS)

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.

Bulzan, Dan

2007-01-01

127

Pilot scale combustion evaluation of waste and alternate fuels, phase 3  

Microsoft Academic Search

The results of three studies which evaluated the combustion of waste products and alternate fuels are presented. The first evaluated a distributed air staging concept for NOx control in pulverized coal fired systems. The second evaluated combustion control techniques and NO emissions when firing coal\\/oil mixtures. The third evaluated emissions and combustion characteristics of refuse derived fuel (RDF) cofired with

R. A. Brown; C. F. Busch

1980-01-01

128

Advanced modeling of large-scale oxy-fuel combustion processes  

E-print Network

radiative heat transfer and combustion chemistry are two of the fundamental issues. Efforts are made in bothAdvanced modeling of large-scale oxy-fuel combustion processes Chungen Yin Department of Energy Technology, Aalborg University, DK-9220 Aalborg, Denmark, chy@et.aau.dk Introduction Oxy-fuel combustion

Yin, Chungen

129

A jet fuel surrogate formulated by real fuel properties  

SciTech Connect

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)

Dooley, Stephen; Won, Sang Hee; Chaos, Marcos; Heyne, Joshua; Ju, Yiguang; Dryer, Frederick L. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States); Kumar, Kamal; Sung, Chih-Jen [School of Engineering, University of Connecticut, Storrs, CT (United States); Wang, Haowei; Oehlschlaeger, Matthew A. [Department of Mechanical, Aerospace, and Nuclear Engineering, Rensselaer Polytechnic Institute, Troy, NY (United States); Santoro, Robert J.; Litzinger, Thomas A. [Propulsion Engineering Research Center, The Pennsylvania State University, University Park, PA (United States)

2010-12-15

130

Deceleration fuel cut device for internal combustion engines  

SciTech Connect

A deceleration fuel cut device adapted to interrupt the supply of fuel to an internal combustion engine when a detected actual engine rotational speed is higher than a predetermined value, and simultaneously a detected intake pipe pressure is lower than a predetermined value. The predetermined engine speed value is set to lower values as the detected actual engine temperature increases. The predetermined intake pipe pressure value is determined as a function of the detected actual engine speed. The predetermined intake pipe pressure value and/or the predetermined engine speed value may be set at different values between the time of initiation of cutting off the fuel supply and the time of termination of same, to impart a hysteresis characteristic to the fuel cut operation.

Otobe, Yu.; Umesaki, S.; Yamato, A.

1984-03-06

131

Acoustic sensor for determining combustion properties of natural gas  

Microsoft Academic Search

Since natural gas is not refined its composition depends on when and where it is recovered. This variation in composition results in problems in the optimal performance of combustion systems using natural gas as a fuel. The speed of sound in natural gas can be used to measure the fuel quality, since the speed of sound in a gas changes

R. M. Lueptow; S. Phillips

1994-01-01

132

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

SciTech Connect

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.

Bunting, Bruce G [ORNL; Bunce, Michael [ORNL

2012-01-01

133

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

NASA Astrophysics Data System (ADS)

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.

Bariš?, Vesna; Zabetta, Edgardo Coda; Sarkki, Juha

134

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

SciTech Connect

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.

Siegel, W.O.; McCabe, R.W.; Chun, W.; Kaiser, E.W.; Perry, J.; Henig, Y.I.; Trinker, F.H.; Anderson, R.W. (Ford Motor Company, Dearborn, MI (United States))

1992-07-01

135

Effect of market fuel variation and cetane improvers on CAI combustion in a GDI engine  

E-print Network

There is continued interest in improving the fuel conversion efficiency of internal combustion engines and simultaneously reducing their emissions. One promising technology is that of Controlled Auto Ignition (CAI) combustion. ...

Cedrone, Kevin David

2010-01-01

136

Fast and slow active control of combustion instabilities in liquid-fueled combustors  

NASA Astrophysics Data System (ADS)

This thesis describes an experimental investigation of two different novel active control approaches that are employed to suppress combustion instabilities in liquid-fueled combustors. A "fast" active controller requires continuous modulation of the fuel injection rate at the frequency of the instability with proper phase and gain. Use of developed optical tools reveals that the "fast" active control system suppresses the instability by changing the nearly flat distribution of the phase between pressure and heat release oscillations to a gradually varying phase distribution, thus dividing the combustion zone into regions that alternately damp and drive combustor oscillations. The effects of these driving/damping regions tend to counter one another, which result in significant damping of the unstable oscillations. In contrast, a "slow" active controller operates at a rate commensurate with that at which operating conditions change during combustor operation. Consequently, "slow" controllers need infrequent activation in response to changes in engine operating conditions to assure stable operation at all times. Using two types of fuel injectors that can produce large controllable variation of fuel spray properties, it is shown that by changing the spray characteristics it is possible to significantly damp combustion instabilities. Similar to the aforementioned result of the "fast" active control study, "slow" change of the fuel spray properties also modifies the nearly flat phase distribution during unstable operation to a gradually varying phase distribution, resulting in combustor "stabilization". Furthermore, deconvolutions of CH*-chemiluminescence images reveal the presence of vortex-flame interaction during unstable operation. Strong driving of instabilities occurs where the mean axial velocity of the flow is approximately zero, a short distance downstream of the flame holder where a significant fraction of the fuel burns in phase with the pressure oscillations. It is shown that the "fast" and "slow" active control approaches suppress combustion instabilities in a different manner. Nevertheless, the both control approaches successfully suppress combustion instabilities by modifying the temporal and spatial behavior of the combustion process heat release that is responsible for driving the instability.

Lee, Jae-Yeon

137

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

SciTech Connect

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.

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

1990-08-01

138

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

139

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

140

Aerodynamic properties of turbulent combustion fields  

NASA Technical Reports Server (NTRS)

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.

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

1985-01-01

141

Injection, atomization, ignition and combustion of liquid fuels in high-speed air streams. Annual scientific report 1 December 81-31 December 82  

Microsoft Academic Search

A simulation approach to studying hot flow subsonic cross-stream fuel injection problems in a less complex and costly cold flow facility was developed. A typical ramjet combustion chamber fuel injection problem was posed where ambient temperature fuel (Kerosene) is injected into a hot airstream. This case was transformed through two new similarity parameters involving injection and freestream properties to a

Schetz

1983-01-01

142

Study of Hg and SO 3 behavior in flue gas of oxy-fuel combustion system  

Microsoft Academic Search

Oxy-fuel combustion systems have been under development to reduce CO2 emissions from coal-fired power plants. In oxy-fuel combustion system, Hg in the flue gas causes corrosion in CO2 purification and compression units. Also, SO3 in the flue gas corrodes the equipment and ducts of oxy-fuel combustion system. Therefore, Hg and SO3 need to be removed.Babcock-Hitachi conducted tests using a 1.5MWth

Yoshiaki Mitsui; Noriyuki Imada; Hirofumi Kikkawa; Atsushi Katagawa

2011-01-01

143

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

Microsoft Academic Search

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

Hongguang Jin; Masaru Ishida

2000-01-01

144

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

SciTech Connect

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.

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

2003-08-24

145

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

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

146

The Impact of Biomass Fuels on Flame Structure and Pollutant Formation during Biomass Cofiring Combustion.  

E-print Network

??Cofiring of biomass in pulverized coal boilers for large-scale power generation requires that current combustion standards of stability, reliability, emission and fuel conversion efficiency are… (more)

Holtmeyer, Melissa Lauren

2012-01-01

147

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

NASA Technical Reports Server (NTRS)

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.

Gordon, S.

1982-01-01

148

Biomedically relevant chemical and physical properties of coal combustion products.  

PubMed Central

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

Fisher, G L

1983-01-01

149

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

NASA Technical Reports Server (NTRS)

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.

Canada, G. S.

1974-01-01

150

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

PubMed

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

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

2014-01-01

151

Adaptive air/fuel ratio controller for internal combustion engine  

SciTech Connect

An air/fuel ratio controller for an internal combustion engine including two memories each having numbers stored at locations addressed by engine operating points with the locations addressed by the engine operating points being updated during closed loop operation in accord with the value of a closed loop adjustment of the air/fuel ratio. Each memory location in the first memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored tracks adjustment value producing the predetermined desired closed loop air/fuel ratio during varying values of engine operating parameters. Each memory location in the second memory is updated during operation of the engine at the corresponding operating point in accord with an update time constant having a value so that the number stored is the average of the values producing the predetermined closed loop air/fuel ratio during varying values of engine operating parameters. The first memory is used during closed loop operation to preset the closed loop adjustment at least when the engine first operates at an operating point and the second memory is utilized during open loop operation to adjust the air/fuel ratio by an amount determined at least in part by the number stored in the second memory at locations addressed by the engine operating point.

Chiesa, A.F.; Evans, D.G.; Norford, J.R.; Zahorchak, J.A.

1982-01-12

152

Combustion of liquid fuel in the counter-swirled jets of a gas turbine plant annular combustion chamber  

NASA Astrophysics Data System (ADS)

Tests were carried out on an annular combustion chamber rig with a stabilizer of the type used in the GTN-25 gas turbine plant to determine the feasibility of burning a liquid fuel (diesel fuel, GOST 4749-73) in a combustion chamber of this type. Very high performance was obtained for a number of important characteristics of the microflame combustion process in counterswirled jets where all the air was supplied through the front unit of the chamber. However, the tests did not make it possible to solve some of the problems which arise when operating under full-scale conditions, such as the required high combustion efficiency under variable operating conditions of a gas turbine plant; elimination of soot formation at the walls of the stabilizer and the internal surfaces of the pipes supplying fuel to the atomizers; and a decrease in smoking under conditions of excess air factor.

Tumanovskii, A. G.; Semichastnyi, N. N.; Sokolov, K. Iu.

1986-03-01

153

Combustion characteristics in the transition region of liquid fuel sprays  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

154

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

DOEpatents

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.

McMillian, Michael H. (Fairmont, WV)

1992-01-01

155

Fireside Corrosion in Oxy-fuel Combustion of Coal  

SciTech Connect

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.

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

2013-11-25

156

Health effects of fossil-fuel combustion products: needed research  

SciTech Connect

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).

Not Available

1980-01-01

157

Mach 2 combustion characteristics of hydrogen/hydrocarbon fuel mixtures  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

158

Mach 2 combustion characteristics of hydrogen/hydrocarbon fuel mixtures  

NASA Technical Reports Server (NTRS)

The combustion of H2/CH4 and H2/C2H4 mixtures containing 10-70 vol pct hydrocarbon at cumbustor inlet Mach number 2 and temperatures 2000-4000 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 at 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.

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

1987-01-01

159

Combustion synthesis and optical properties of ceria doped gadolinium-oxide nanopowder  

NASA Astrophysics Data System (ADS)

The Ceria doped Gadolinium (Gd2O3) nanopowder was synthesized by combustion synthesis by using urea as a fuel. The combustion synthesis method which is reported here is advantageous from the perspectives of small size of the nanoparticle. The structural and photoluminescence (PL) property of sample was studies. Gd2O3:Ce3+ nanoparticles exhibit green emission around 543 nm. The result of XRD show that synthesized sample has cubic structure. The average size of particle is found to be 45 nm. The surface morphology of the films is also presented.

Tamrakar, Raunak Kumar; Bisen, D. P.

2013-06-01

160

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

ERIC Educational Resources Information Center

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)

Lloyd, William G.; Davenport, Derek A.

1980-01-01

161

A jet fuel surrogate formulated by real fuel properties Stephen Dooley a,*, Sang Hee Won a  

E-print Network

Chaos a , Joshua Heyne a , Yiguang Ju a , Frederick L. Dryer a , Kamal Kumar b , Chih-Jen Sung b, Rensselaer Polytechnic Institute, Troy, NY, USA d Propulsion Engineering Research Center, The Pennsylvania Group additivity Fuel properties Combustion jet-A a b s t r a c t An implicit methodology based

Ju, Yiguang

162

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...

163

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

EPA Science Inventory

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

164

Interaction Effects During Combustion of Linear Arrays of Gaseous Fuel Pockets  

Microsoft Academic Search

The numerical solution for the combustion of an infinite linear array of dense fuel gas pockets in a quiescent ambient is discussed in the present work. Fuel mass, flame, and gas pocket shape behaviors are analyzed in order to quantify the interference effects. The combustion process is considered isobaric. The model is based on mass, momentum, energy, and species conservation

Aldélio Bueno Caldeira; Albino José Kalab Leiroz; Helcio Rangel Barreto Orlande

2008-01-01

165

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

Microsoft Academic Search

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

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

2011-01-01

166

DOES FOSSIL FUEL COMBUSTION LEAD TO GLOBAL WARMING? Stephen E. Schwartz  

E-print Network

DOES FOSSIL FUEL COMBUSTION LEAD TO GLOBAL WARMING? Stephen E. Schwartz Environmental Chemistry--Fri, Dec 1, 2006 DOES FOSSIL FUEL COMBUSTION LEAD TO GLOBAL WARMING? Stephen E. Schwartz Environmental Chemistry Division Brookhaven National Laboratory Upton NY 11973 USA [Abstract] Tropospheric sulfate

Schwartz, Stephen E.

167

Reactivity study on a novel hydrogen fueled chemical-looping combustion  

Microsoft Academic Search

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

Hongguang Jin; Masaru Ishida

2001-01-01

168

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

E-print Network

believed to cause fuel formation for in-situ combustion have been studied and modeled. A thin, packed bedPaper Number 15736-PA Title Reaction Kinetics of Fuel Formation for In-Situ Combustion Authors Abu-Khamsin, Sidqi A., Stanford U.; Brigham, William E., Stanford U.; Ramey Jr., Henry J., Stanford U. Journal SPE

Abu-Khamsin, Sidqi

169

Global Emissions of Nitrogen and Sulfur Oxides in Fossil Fuel Combustion 1970–1986  

Microsoft Academic Search

Statistical models previously introduced by the authors for estimating emission rates from rates of fuel combustion have been utilized to obtain emissions of nitrogen and sulfur gases in fossil fuel combustion for every country in the world for every year from 1970 to 1986. Changes in the global emission rates of these gases are presented together with the trends over

Sultan Hameed; Jane Dignon

1992-01-01

170

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

PubMed

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 ?m for crop residues and high caking coals and <0.7 ?m for the tested low caking briquettes. PMID:21375317

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

171

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

Code of Federal Regulations, 2012 CFR

...false How do I determine the total sulfur content of the turbine's combustion...4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the fuel being fired...

2012-07-01

172

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

Code of Federal Regulations, 2011 CFR

...false How do I determine the total sulfur content of the turbine's combustion...4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the fuel being fired...

2011-07-01

173

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

Code of Federal Regulations, 2013 CFR

...false How do I determine the total sulfur content of the turbine's combustion...4360 How do I determine the total sulfur content of the turbine's combustion fuel? You must monitor the total sulfur content of the fuel being fired...

2013-07-01

174

A new comprehensive reaction mechanism for combustion of hydrocarbon fuels  

SciTech Connect

A detailed chemical kinetic model has been developed that accurately 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 semiempirical 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 comprehensive detailed reaction mechanisms in two important 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 use to test the reaction mechanisms, 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. The construction of the reaction mechanisms and selected comparisons with experimental data are described that illustrate the generality of the model.

Ranzi, E.; Sogaro, A.; Gaffuri, P.; Pennati, G. (Politecnico di Milano (Italy). Dipt. di Chimica Industriale ed Ingegneria Chimica); Westbrook, C.K.; Pitz, W.J. (Lawrence Livermore National Lab., CA (United States))

1994-11-01

175

Experimental investigation of fuel combustion in counterflowing high-temperature air flow  

Microsoft Academic Search

The possibility of using high-energy synthetic hydrocarbon fuels, borane fuels, as well as borohydrocarbon fuels are currently being studied for use by various kinds of aircraft with jet engines. The problem addressed in this work included experimental determination of the geometric characteristics of the vaporization and combustion zones of borohydrocarbon fuel sprayed in a counterflowing air flow and comparing them

Y. M. Annushkin; A. N. Knyazev; N. S. Loshenkova

1983-01-01

176

Corrosion of experimental superheater alloys in waste fuel combustion  

SciTech Connect

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

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

1997-08-01

177

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

SciTech Connect

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

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

1997-12-31

178

Internal combustion engine fuel controls. (Latest citations from the US Patent database). Published Search  

SciTech Connect

The bibliography contains citations of selected patents concerning fuel control devices and methods for use in internal combustion engines. Patents describe air-fuel ratio control, fuel injection systems, evaporative fuel control, and surge-corrected fuel control. Citations also discuss electronic and feedback control, methods for engine protection, and fuel conservation. (Contains a minimum of 232 citations and includes a subject term index and title list.)

Not Available

1992-12-01

179

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

SciTech Connect

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.

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

1999-07-01

180

Review and analysis of spray combustion as related to alternative fuels  

Microsoft Academic Search

A review of the literature on spray combustion was conducted, with particular emphasis on theoretical and experimental work on droplet and spray combustion relevant to the use of alternate fuels (mainly liquid fuels derived from coal and shale). Principal differences between coal-derived liquid fuel and petroleum have been identified. Coal liquids have a lower hydrogen-to-carbon ratio, higher aromatic compound content,

C. H. Black; H. H. Chiu; J. Fischer; J. M. Clinch

1979-01-01

181

Study on Combustion Oscillation of Premixed Flame with Pilot Fuel at Elevated Pressures  

NASA Astrophysics Data System (ADS)

Acoustically-coupled combustion oscillation is studied for premixed flame with pilot fuel to be used in gas turbine combustors. Premixed gas is passed through swirl vanes and burnt with the centrally injected pilot fuel. The dependencies of pressure, fuel to air ratio, premixed fuel rate, inlet velocity and air temperature on the combustion oscillation are investigated. Two kinds of oscillation modes of ˜100Hz and ˜350Hz are activated according to inlet velocities. Fluctuating pressures are amplified when the premixed fuel rate is over ˜80% at elevated pressures. The fluctuating pressure peak moves to a higher premixed fuel ratio region with increased pressure or fuel to air ratio for the Helmholz type mode. Combustion oscillation occurs when the pilot fuel velocity is changed proportionally with the flame length.

Ohtsuka, Masaya; Yoshida, Shohei; Hirata, Yoshitaka; Kobayashi, Nariyoshi

182

Advanced fuel system technology for utilizing broadened property aircraft fuels  

NASA Technical Reports Server (NTRS)

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.

Reck, G. M.

1980-01-01

183

Light absorption by primary particles from fossil-fuel combustion: Implications for radiative forcing  

NASA Astrophysics Data System (ADS)

Interactions of visible radiation with atmospheric aerosols are important to the heat balance of the Earth. Accurate emission inventories of particles from combustion are required to predict anthropogenically-induced changes in the radiative balance. I present measurements of the optical properties of particles from several types of combustion and compare them with assumptions used in previous emission inventories. Emissions from an indirect-injection diesel engine were similar to expected values. However, a second engine with a direct-injection scheme emitted about 100 times the expected amount of both mass and light absorption because of a poor injection pattern. Total emissions from vehicles depend critically on the number of such "catastrophic" units in operation. Absorption emitted from a low-technology industrial lignite-burning furnace was about 20 times lower than previous estimates; the emitted particles contained partially aromatized carbon. Burning bituminous coal in a Chinese-style domestic combustor yielded significant light absorption, similar to published emission factors. Combustion of both coal briquettes obtained from China and lignite resulted in very low light absorption because tar release from these fuels was low. Combining the measurement and modeling results with an extensive literature survey, I estimated central, low and high values of emission factors for different fuels and combustion sectors. I then calculated a global emission inventory of light-absorbing carbon from fossil-fuel combustion. The total emission of light-absorbing carbon for 1994 is 3.7 Tg, about half the magnitude of previously published emission inventories. The upper and lower uncertainty boundaries are 0.8 and 44 Tg year--1. The largest sources of uncertainty are emission characteristics for residential coal and the existing fraction of "catastrophic" units in operation. Emission inventories for organic carbon (central value of 5.1 Tg year--1, with a range of 0.5-42 Tg year--1) and for primary particles (3 x 1028 year--1) are also presented. Radiative forcing by light-absorbing particles on a global-average basis is small, but regional effects are significant. In regions with high area-specific emissions, the central estimate of top-of-atmosphere forcing is about +0.7 W m--2, and the upper bound is around +4.0 W m --2.

Bond, Tami Christine

184

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

NASA Technical Reports Server (NTRS)

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.

Molnar, Melissa; Marek, C. John

2003-01-01

185

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

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

186

Cogeneration system with low NO sub x combustion of fuel gas  

Microsoft Academic Search

This patent describes a cogeneration system for the production of electricity and refrigeration with low NOâ 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

Garbo

1991-01-01

187

An Evaluation of some Health Risks of the Pollution from Fossil Fuel Combustion  

E-print Network

94-27 An Evaluation of some Health Risks of the Pollution from Fossil Fuel Combustion Guy Landrieu is proceeding to the implementation oF this methodology in France for the fossil fuel cycles (coal/ oil, natural an accounting framework for identifying and quantifying the extemal costs associated with fuel cycles. A general

Paris-Sud XI, Université de

188

Estimating particulate matter health impact related to the combustion of different fossil fuels  

E-print Network

Estimating particulate matter health impact related to the combustion of different fossil fuels generated a web map service that allows to access information on fuel dependent health effects due a simulation. Combined with a dedicated emission inventory PM2.5 maps specified by fuel type were generated

Paris-Sud XI, Université de

189

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...

190

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

SciTech Connect

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.

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

1991-02-01

191

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

Microsoft Academic Search

Recently, a number of environmental problems caused from fossil fuel combustion have been focused on. In addition, with the\\u000a eventual depletion of fossil energy resources, hydrogen gas is expected to be an alternative energy resource in the near future.\\u000a It is characterized by high energy per unit weight, high reaction rate, wide range of flammability and the low emission property.

Makoto Yamamoto; Junichi Ikeda; Kazuaki Inaba

2006-01-01

192

Performance of a controllable premixed combustion engine fueled with dimethyl ether  

Microsoft Academic Search

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

Jun Song; Zhen Huang; Xinqi Qiao; Wanli Wang

2004-01-01

193

????????????????????????????????????????????? Fixed Bed Study of the Fuel Biomass Combustion in a Fixed Bed  

Microsoft Academic Search

This thesis were carried out to receive the fundamental data on parameters that characterize the combustion of bagasse in a fixed bed reactor that composed of flame propagation velocity and combustion rate. The experiments were performed as batch and bagasse was used as fuel. The variables investigated are air supply in the rates of 200, 300 and 400 LPM or

Sunthorn Laaongnaun; Suthum Patumsawad

194

Acoustic effects during the combustion of gaseous fuels in a bubbling fluidized bed  

Microsoft Academic Search

Acoustic effects accompany the combustion of gaseous fuels in bubbling fluidized beds of inert materials. In an exploratory study of this effect, using a laboratory-size fluidized bed in which a mixture of propane and butane was burned, the bed’s temperature was monitored continuously and the acoustic effects were recorded. The temperature ranges over which combustion was “noisy” and “quiet” were

W. ?ukowski

1999-01-01

195

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...

196

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...

197

Numerical study on supersonic combustion with cavity-based fuel injection  

Microsoft Academic Search

The present study describes the numerical investigations concerning the combustion enhancement when a cavity is used for the hydrogen fuel injection through a transverse slot nozzle into a supersonic hot air stream. The cavity is of interest because recirculation flow in cavity would provide a stable flame holding while enhancing the rate of mixing or combustion. Several inclined cavities with

Kyung Moo Kim; Seung Wook Baek; Cho Young Han

2004-01-01

198

ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal  

E-print Network

ORIGINAL PAPER Fireside Corrosion in Oxy-fuel Combustion of Coal Gordon R. Holcomb · Joseph Tylczak the nature of coal ash deposits. Wigley and Goh [1] reported that particles in oxy-fired deposits, compared

Laughlin, David E.

199

Influence of fuel quality on level of ionization of combustion products in gas turbine engines  

SciTech Connect

As the requirements imposed on gas turbine engines for economy, completeness of fuel, combustion, and smoke level and toxicity of exhaust have become severe, research methods are being developed and GTE combustion chambers are being designed on the basis of the known phenomenon of chemical ionization of a flame. In this paper the dependence of the ionization level on the contents of sodium, vanadium, sulfur, aromatics, and unsaturates in the fuel is investigated. Results indicate that fuel quality indexes of the contents of the above factors do have substantial effects on the level of ionization of the combustion chamber. Design of combustion chambers must therefore be carried out with fuel standards for which these quality indexes are restricted to sufficiently narrow limits.

Seregin, E.P.; Ozerov, E.A.; Petrov, V.I.; Samoilov, I.B.; Stotland, S.I.

1983-11-01

200

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

E-print Network

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

Hong, Jongsup

2009-01-01

201

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

SciTech Connect

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.

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

1982-12-01

202

Advanced fuel system technology for utilizing broadened property aircraft fuels  

NASA Technical Reports Server (NTRS)

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.

Reck, G. M.

1980-01-01

203

Biofuels Combustion  

NASA Astrophysics Data System (ADS)

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.

Westbrook, Charles K.

2013-04-01

204

Biofuels combustion.  

PubMed

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

Westbrook, Charles K

2013-01-01

205

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

Microsoft Academic Search

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

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

1997-01-01

206

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

E-print Network

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

207

Effect of fuel binder and oxidiser particle diameter on the combustion of ammonium perchlorate based propellants  

Microsoft Academic Search

The decomposition and combustion behaviour of ammonium perchlorate (AP) and simple bi-propellant systems were studied. Three types of fuel binders were used in order to examine the role of binder on the combustion process. Paraffin wax was chosen as a simple model fuel, and AP\\/3–9% (mass%) paraffin wax mixtures were used. It was observed that the paraffin melted and volatilized

A. Al-Harthi; A. Williams

1998-01-01

208

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

SciTech Connect

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.

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

2005-05-01

209

A cycle simulation of coal particle fueled reciprocating internal-combustion engines  

E-print Network

, and unburned fuel mass fraction for the class D engine . ]0] LIST OF NOMENCLATURE A. ATDC Pre-exponential rate constant Particle surface area After top dead center Exhaust port area Combustion chamber surface area including head, cylinder walls... between par- ticles and the combustion chamber walls Qrel Qsr Total heat release rate from the fuel Heat release rate from particle surface reactions Q Heat of reaction Convective heat transfer rate to the cyl- inder walls using Woschni...

Rosegay, Kenneth Harold

2012-06-07

210

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

SciTech Connect

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)

None

1980-11-01

211

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

SciTech Connect

A process and apparatus for the production of heat, equivalent in clarity and cleanliness to that of propane, butane or natural gas, but at a lower cost and without the problems or dangers of storage nor risks of fire or explosion during handling, by means of the instantaneous combustion of diafanous liquid petroleum, diesel or other similar combustible fuels mixed with compressed air in an environment which is neither contaminated nor degraded. Thus, it is possible to regulate the flow and simultaneously divide each volume of combustible liquid into particles so small that they distribute and integrate themslves homogenously in a volume of air proportionally adequate for proper combustion.

Mendoza, F.C.

1980-10-07

212

Numerical simulation of the formation of nitric oxides in the combustion of coal-dust fuel  

Microsoft Academic Search

A mathematical model and a method of calculating two-phase flows and heat and mass transfer in industrial combustion chambers\\u000a operating on coal-dust fuels are given. The numerical model of coal-dust combustion in a high-temperature turbulent flow is\\u000a based on three-dimensional steady-state equations of mechanics of heterogeneous media and describes the processes of yield\\u000a and combustion of fuel volatiles, afterburning of

A. V. Starchenko

1998-01-01

213

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

E-print Network

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

Chavannavar, Praveen Shivshankar

2005-11-01

214

The properties of hydrogen as fuel tomorrow in sustainable energy system for a cleaner planet  

Microsoft Academic Search

The Global energy system transition from fossil fuel to hydrogen utilization is described. Environmental benefits of the combustion of hydrogen are reported. World carbon emissions from fossil fuel are schematized in connection with the opportunities of using hydrogen. The atomic hydrogen\\/carbon ratio and chemical properties of hydrogen are described. Pollutants of the energy system in our planet and hydrogen production

Magdalena Momirlan; T. N. Veziroglu

2005-01-01

215

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

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

216

The effect of azeotropism on combustion characteristics of blended fuel pool fire.  

PubMed

The effect of azeotropism on combustion characteristics of blended fuel pool fire was experimentally studied in an open fire test space of State Key Laboratory of Fire Science. A 30 cm × 30 cm square pool filled with n-heptane and ethanol blended fuel was employed. Flame images, burning rate and temperature distribution were collected and recorded in the whole combustion process. Results show that azeotropism obviously dominates the combustion behavior of n-heptane/ethanol blended fuel pool fire. The combustion process after ignition exhibits four typical stages: initial development, azeotropic burning, single-component burning and decay stage. Azeotropism appears when temperature of fuel surface reaches azeotropic point and blended fuel burns at azeotropic ratio. Compared with individual pure fuel, the effect of azeotropism on main fire parameters, such as flame height, burning rate, flame puffing frequency and centerline temperature were analyzed. Burning rate and centerline temperature of blended fuel are higher than that of individual pure fuel respectively at azeotropic burning stage, and flame puffing frequency follows the empirical formula between Strouhal and Froude number for pure fuel. PMID:24632362

Ding, Yanming; Wang, Changjian; Lu, Shouxiang

2014-04-30

217

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

218

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

SciTech Connect

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.

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

1990-04-01

219

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

SciTech Connect

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.

Wachter, E.A.; Gammage, R.B.; Haas, J.W. III; Wilson, D.L. (Oak Ridge National Lab., TN (United States)); DePriest, J.C.; Wade, J. (Midwest Technical, Inc., Oak Ridge, TN (United States)); Ahmad, N.; Sibtain, F.; Zahid Raza, M. (Pakistan Council of Scientific and Industrial Research Labs., Karachi (Pakistan))

1992-10-01

220

Characterisation of coal blends for pulverised fuel combustion  

Microsoft Academic Search

This study evaluates the effect of blending on the combustion characteristics of pulverised coal through the testing of six coals and fifteen coal blends in an isothermal plug flow reactor (IPFR). The aim of the test was to assess whether the combustion behaviour of blends could be predicted from that of the parent coals. For blends of bituminous coals, an

J Haas; M Tamura; R Weber

2001-01-01

221

Synthetic and Jet Fuels Pyrolysis for Cooling and Combustion Applications.  

E-print Network

of supersonic combustion ramjet (SCRamjet) [1]. For such high velocity, the total temperature of external air combustion chamber and at proposing some parameters to enable the control of such a complex technology, considering the flow velocity, can reach 1650 K at Mach 6 and 4950 K at Mach 12. This produces a dramatic

Boyer, Edmond

222

The effect of limestone on the combustion of fuel blends  

Microsoft Academic Search

Combustion profiles of coal-limestone-paper blends were studied using thermogravimetric\\/ Fourier transform infrared spectroscopy\\u000a (TG\\/FTIR). The role of limestone in promoting the initial combustion of coal-paper blends and its ability to absorb sulphur\\u000a oxides were examined.

T. C. Roth; J. T. Riley; W. P. Pan

1993-01-01

223

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

SciTech Connect

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.

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

2000-01-04

224

Determination of the main parameters influencing forest fuel combustion dynamics  

Microsoft Academic Search

This work aims to characterize pine needles as a fuel for a better understanding of the behaviour of forest fuels in wildland fires. It does this in two ways: classify vegetation as a fuel for forest fires and understand the role of transport mechanisms in fuel beds. For this purpose, the physical and chemical characteristics of each fuel are taken

P. Bartoli; A. Simeoni; H. Biteau; J. L. Torero; P. A. Santoni

2011-01-01

225

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

226

Ash behavior during combustion and deposition in coal-fueled gas turbines  

Microsoft Academic Search

Chemical and physical transformations of coal ash during combustion and deposition in gas turbine environments are studied. Extensive characterization of the coal-water-mixture fuel and deposits obtained on deposition pins and turbine nozzle vanes has been performed. The behavior of alkali metals is found to be much different from that for petroleum fuels, resulting in lower than expected deposition and probable

C. L. Spiro; S. G. Kimura; C. C. Chen

1987-01-01

227

Review Bomb calorimeters for determination of the specific combustion heat of fuels  

Microsoft Academic Search

Presently, due to commercialization and decentralization of the fuel shipment system in the former USSR countries, the quality control of the fuel used in power engineering and on industrial enterprizes has grown sharply in importance. In order to carry out quality control, reliable and convenient measuring instruments are required. The specific heat of combustion (SHC) is the main power-engineering characteristic

L. I. Vorob'yov; T. G. Grishchenko; L. V. Dekusha

1997-01-01

228

ANALYSIS OF A FUEL-AIR COMBUSTION MIXTURE BY INFRARED SPECTROSCOPY. Progress Report  

Microsoft Academic Search

A method of analysis is described for the products resulting from the ; incomplete combustion of a mixture of liquid hydrocarbon fuel and excess air. ; Gas sample generally is found to consist of air, unburned fuel, carbon dioxide, ; carbon monoxide, ethylene, and acetylene. These are first determined ; simultaneously by infrared absorptiometry. Then the sample is passed nitrogen

J. S. Whittick; R. F. Muraca

1959-01-01

229

Improving fossil fuel boiler combustion efficiency based on integrating real time simulation with online learning technology  

Microsoft Academic Search

Low-carbon economy, environmental concerns and fuel efficiency demands have placed strong emphasis on the fossil fuel based power plants, requiring them to operate at high efficiency. A number of methods have been applied in the power generation industry to improve boiler efficiency and reduce the emission by optimising the combustion process in many power plants. At the same time, computational

X. Liu; Ramesh Bansal

2012-01-01

230

ASSESSMENT OF ORGANIC CONTAMINANTS IN EMISSIONS FROM REFUSE-DERIVED FUEL COMBUSTION  

EPA Science Inventory

Organic contaminants in emissions from refuse-derived fuel combustion were investigated in a 20-inch-diameter atmospheric fluidized-bed combustor. Combinations of coal/EcoFuel/MSW/toluene were burned inthe combustor with temperatures ranging from 1250 to 1550 degrees F. A Source ...

231

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

SciTech Connect

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.

Urciuolo, M.; Barone, A.; D'Alessio, A.; Chirone, R. [CNR, Rome (Italy). Institute of Research for Combustion

2008-12-15

232

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

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

233

Vaporizer design criteria for ethanol fueled internal combustion engines  

E-print Network

of Advisory Committee: Dr. Wayne A. LePori At present, global energy supplies depend mainly on nonrenewable fossil fuels. Alternative fuel sources will be needed at the end of the petroleum fuel era, Researchers have been working on alternatives... of theoretical and nondimensional approaches. . 59 CHAPTER I INTRODUCTION Global demand for energy has increased, but supplies of fossil fuels are limited. As the end of the petroleum fuel era approaches, alternative fuel sources will be needed to replace...

Ariyaratne, Arachchi Rallage

2012-06-07

234

ANNEX 4 IPCC Reference Approach for Estimating CO2 Emissions from Fossil Fuel Combustion  

E-print Network

It is possible to estimate carbon dioxide (CO 2) emissions from fossil fuel consumption using alternative methodologies and different data sources than those described in the Estimating Emissions from Fossil Fuel Combustion Annex. For example, the UNFCCC reporting guidelines request that countries, in addition to their “bottom-up ” sectoral methodology, complete a "top-down " Reference Approach for estimating CO 2 emissions from fossil fuel combustion. Section 1.3 of the Revised 1996 IPCC Guidelines for National Greenhouse Gas Inventories: Reporting Instructions states, “If a detailed, Sectoral Approach for energy has been used for the estimation of CO2 from fuel combustion you are still asked to complete…the Reference Approach…for verification purposes ” (IPCC/UNEP/OECD/IEA 1997). This reference method estimates fossil fuel consumption by adjusting national aggregate fuel production data for imports, exports, and stock changes rather than relying on end-user consumption surveys. The basic principle is that once C-based fuels are brought into a national economy, they are either saved in some way (e.g., stored in products, kept in fuel stocks, or left unoxidized in ash) or combusted, and therefore the C in them is oxidized and released into the atmosphere. Accounting for actual consumption of fuels at the sectoral or sub-national level is not required. The following discussion provides the detailed calculations for estimating CO2 emissions from fossil fuel combustion from the United States using the IPCCrecommended Reference Approach. Step 1: Collect and Assemble Data in Proper Format

unknown authors

235

Retene Emission from Residential Solid Fuels in China and Evaluation of Retene as a Unique Marker for Soft Wood Combustion  

PubMed Central

Retene (1-methyl-7-isopropylphenanthrene) is often used as a marker for softwood combustion and for polycyclic aromatic hydrocarbon (PAH) source apportionment. The emission factors of retene (EFRET) from 11 crop residues, 27 firewood and 5 coals were measured using traditional rural Chinese stoves. Retene was measured in combustion emissions from all of the residential fuels tested and EFRET varied significantly among the fuels due to the differences in fuel properties and combustion conditions. EFRET for pine (0.34±0.08 mg/kg) and larch (0.29±0.22 mg/kg) were significantly higher than those of other wood types, including fir and cypress (0.081±0.058 mg/kg). However, EFRET for crop residues varied from 0.048±0.008 to 0.37±0.14 mg/kg and were not significantly lower than those for softwood (0.074±0.026 to 0.34±0.08 mg/kg). The EFRET for coal were very high and ranged from 2.2±1.5 (anthracite briquette) to 187±113 mg/kg (raw bituminous chunk). EFRET was positively correlated with EFs of co-emitted particulate matter (EFPM) and phenanthrene (EFPHE) for crop residue and coal, but not for wood. In addition, the ratios of EFPHE/EFRET and EFPM/EFRET for coals were much lower than those for crop residues and wood. These data suggest that retene is not a unique PAH marker for softwood combustion and that coal combustion, in particular, should be taken into account when retene is used for PAH source apportionment. PMID:22452486

Shen, Guofeng; Tao, Shu; Wei, Siye; Zhang, Yanyan; Wang, Rong; Wang, Bin; Li, Wei; Shen, Huizhong; Huang, Ye; Yang, Yifeng; Wang, Wei; Wang, Xilong; Massey Simonich, Staci L.

2012-01-01

236

Study Into Combustion of Sewage Sludge as Energetic Fuel / Badania Spalania OSADÓW ?CIEKOWYCH Jako Paliwa Energetycznego  

NASA Astrophysics Data System (ADS)

Along with the development of civilisation, it can be observed that the amount of waste of different type is growing and the preparation process for further usage of the waste or the utilization process differs. What is to be focused on is municipal sewage sludge which, due to its energetic properties, constitutes a valuable fuel. The problem of usage of municipal sewage sludge remains still unsolved, which stems both from the increasing amount of such waste, and from the lack of properly adjusted systems for thermal processing thereof. What is of an additional obstacle are the increasingly stricter legal regulations regarding disposal of sewage sludge after the year 2013; hence, it is necessary to consider various benefits resulting from thermal processing of such waste. This work presents an overview of methods of disposal of sewage sludge, taking into consideration, in particular, thermal methods including the process of combustion and co-combustion as a means of successful utilization. The research section of the work presents the results of study into the mechanism and kinetics of combustion of sewage sludge in various conditions of the process carried out in air flow. Combustion of sewage sludge has been compared against combustion of coal and biomass. Wraz z rozwojem cywilizacji zaobserwowa? mo?na post?puj?ce powstawanie ró?nego rodzaju odpadów ró?ni?cych si?, m.in. sposobem przygotowania do dalszego wykorzystania, czy procesem utylizacji. Na szczególn? uwag? zas?uguj? komunalne osady ?ciekowe, które z uwagi na w?a?ciwo?ci energetyczne stanowi? cenne paliwo. Problem wykorzystania komunalnych osadów ?ciekowych jest nadal otwarty, a wynika to zarówno z rosn?cej produkcji tych odpadów, jak i braku odpowiednio przystosowanych instalacji do termicznego ich przekszta?cania. Dodatkowym utrudnieniem s? zaostrzaj?ce si? przepisy prawne dotycz?ce sk?adowania osadów ?ciekowych po 2013 r. sk?aniaj?ce tym samym do rozwa?a? nad korzy?ciami p?yn?cymi z termicznej obróbki tych odpadów. W pracy przedstawiono przegl?d sposobów unieszkodliwiania osadów ?ciekowych ze szczególnym uwzgl?dnieniem metod termicznych, g?ównie spalania i wspó?spalania jako drogi do ich sukcesywnej utylizacji. W cz??ci badawczej pracy zaprezentowano wyniki bada? mechanizmu i kinetyki spalania osadów ?ciekowych w ró?nych warunkach procesu prowadzonego w strumieniu powietrza. Spalanie osadów ?ciekowych porównano ze spalaniem w?gla oraz biomasy.

Kijo-Kleczkowska, Agnieszka; ?roda, Katarzyna; Otwinowski, Henryk

2013-12-01

237

Synthesis of alumina powder by the urea-glycine-nitrate combustion process: a mixed fuel approach to nanoscale metal oxides  

NASA Astrophysics Data System (ADS)

Main objective of present work is to study the efficiency of mixed fuel towards solution combustion synthesis of alumina powder, which otherwise prepared by single fuel and study of properties of final product with mixed fuel approach. Two different fuels, glycine and urea, along with aluminium nitrates have been used to prepare nanophase alumina powder. Different fuel to oxidizer ratios and different percentage combination of two fuels were used to prepare six samples. In all samples, nanoscale particle size obtained. Parameter which continuously changes the results of various characterisations is percentage combination of two fuels. In case where percentage of urea is higher than glycine reaction takes place with high exothermicity and hence crystallinity in product phase, whereas glycine promotes amorphous character. With mixed fuel approach, crystallinity can be enhanced easily, by calcinations of powder product at low temperature, because due to mixed urea and glycine, there is already some fraction of crystallinity observed. Overall mixed fuel approach has ability to produce nanophase alumina powder with wide range of particles size.

Sharma, Amit; Rani, Amita; Singh, Ajay; Modi, O. P.; Gupta, Gaurav K.

2014-03-01

238

Combustion of High-Energy-High-Density Fuels  

Microsoft Academic Search

Quantitative analyses of combustion products of a High Energy\\/High Density (HED) hydrocarbon, Methylated Pentacycloundecane Alkene Dinner (MPCU), are presented. This compound is a large molecule, C24H28, which dissolves in large proportions in existing liquid hydrocarbons, such as JP-10, forming stable blends to 50% w\\/w. These blends exhibited a five-fold larger burning rate compared with pure JP-10 droplets. Identification of combustion

C. SEGAL; S. PETHE; K. R. WILLIAMS

2001-01-01

239

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

Microsoft Academic Search

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

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

240

Air and oxy-fuel combustion characteristics of biomass\\/lignite blends in TGA-FTIR  

Microsoft Academic Search

Pyrolysis and combustion behavior of indigenous lignite, olive residue and their 50\\/50wt.% blend in air and oxy-fuel conditions were investigated by using thermogravimetric analyser (TGA) combined with Fourier-transform infrared (FTIR) spectrometer. Pyrolysis tests were carried out in nitrogen and carbon dioxide environments which are the main diluting gasses of air and oxy-fuel environment, respectively. Pyrolysis results of the parent fuels

Nur Sena Yuzbasi; Nevin Selçuk

2011-01-01

241

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

PubMed

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

Sidhu, S; Graham, J; Striebich, R

2001-01-01

242

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

SciTech Connect

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.

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

2008-04-21

243

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

Microsoft Academic Search

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

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

2006-01-01

244

Modeling of the reaction-front propagation during the fixed-bed combustion of solid fuel  

Microsoft Academic Search

A one-dimensional, steady-state mathematical model of solid-fuel combustion in a fixed bed is presented. The model equations and boundary conditions as well as the solution method are presented. Calculation results are shown to agree very well with the experimental data. Calculations indicate that during fixed-bed cocurrent flow combustion a reaction front is formed that propagates in the direction opposite to

2003-01-01

245

An experimental and numerical investigation on hydrogen-hydrocarbon composite fuel combustion  

Microsoft Academic Search

An experimental and numerical study on the combustion characteristics of turbulent diffusion flames of natural gas-hydrogen composite fuel is presented. Three mixtures (90--10%, 80--20% and 65--35% by volume) of natural gas and hydrogen were used. The results are compared with the combustion characteristics of a pure natural gas flame. The following parameters were measured: (i) flame stability (blowout velocity, and

Ahsan Reza Choudhuri

2000-01-01

246

Modeling of Waste-to-Energy Combustion with Continuous Variation of the Solid Waste Fuel  

Microsoft Academic Search

A mathematical model of a mass-burn, waste-to-energy combustion chamber has been developed that includes stochastic representation of the variability of the fuel (municipal solid waste, MSW). The drying, pyrolysis, gasification and combustion processes on the moving grate are governed by several factors such as proximate and ultimate analysis, particle size, moisture, heating value, and bulk density, all of which change

MASATO NAKAMURA; HANWEI ZHANG; KARSTEN MILLRATH; NICKOLAS J. THEMELIS

247

Analysis of fuel system technology for broad property fuels  

NASA Technical Reports Server (NTRS)

An analytical study was performed in order to assess relative performance and economic factors involved with alternative advanced fuel systems for future commercial aircraft operating with broad property fuels. Significant results, with emphasis on design practicality from the engine manufacturer' standpoint, are highlighted. Several advanced fuel systems were modeled to determine as accurately as possible the relative merits of each system from the standpoint of compatibility with broad property fuel. Freezing point, thermal stability, and lubricity were key property issues. A computer model was formulated to determine the investment incentive for each system. Results are given.

Coffinberry, G. A.

1984-01-01

248

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

USGS Publications Warehouse

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.

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

1992-01-01

249

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

PubMed

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

Chen, Luguang; Bhattacharya, Sankar

2013-02-01

250

Distinctive features of operation of an internal combustion engine running on hydrogen-containing fuels  

NASA Astrophysics Data System (ADS)

Experimental investigations have been carried out on an internal combustion engine with hydrogen added to the hydrocarbon fuel, i.e., gasoline. The possibility of improving the energy and environmental indices in the case of hydrogen feed to the engine's air path has been shown. It has been established that increase in the fraction of hydrogen in the fuel mixture causes the operating process of the engine to improve, with the result that the flow rate of gasoline as a function of the H2 fraction decreases by nearly 70%. Considerable reduction in the content of CO, CO2, and CH (of approximately 5-60% depending on the amount of the added H2) is observed. However, adding hydrogen to the fuel-air mixture leads to an increase in the content of nitric oxides in the combustion products because of the growth in the velocity of propagation of the flame and increase in the combustion temperature.

Assad, M. S.; Penyazkov, O. G.

2010-09-01

251

A study on combustion behavior of a diesel fuel spray impinging on a wall  

SciTech Connect

Combustion characteristics of a diesel fuel spray impinging on a wall were studied, using a constant volume combustion vessel. Pressure and temperature inside the vessel, and fuel injection specification were set at the typical values of small DI diesel engines of 90--100 mm cylinder bore size. The indicated pressure analysis and combustion observation indicate that present analysis enables the evaluation of the mixture formation affected by impingement wall, corresponding to a small actual DI diesel engine. By lowering impingement wall temperature from 840 K to 620 K, ignition point shifts upstream along the spray from a portion near the wall, and ignition delay is shortened. Although ignition occurs earlier at shorter impingement length, its ignition time difference become less at shorter ignition delay condition, where, however, the heat release rate changes greatly and it gives a maximum at a certain impingement length. This value almost corresponds to the break up length of fuel spray.

Tomonaga, Takashi; Murai, Kazuyuki; Takano, Takayoshi; Sami, Hiroshi

1996-09-01

252

Combustion characteristics in the transition region of liquid fuel sprays  

NASA Technical Reports Server (NTRS)

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.

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

1984-01-01

253

Modeling of combustion processes in a solid fuel particle  

SciTech Connect

During the production of granules of 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, a commercial finite-element code, run on an IBM 3090, was used to model the physical processes occurring during combustion: heat transfer with a very nonlinear 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 successfully explained the differences in morphology of the granules under different conditions, and lead to control strategies to produce the desired morphology. 10 figs.

Howard, D.W.

1990-01-01

254

Global mercury emissions from combustion in light of international fuel trading.  

PubMed

The spatially resolved emission inventory is essential for understanding the fate of mercury. Previous global mercury emission inventories for fuel combustion sources overlooked the influence of fuel trading on local emission estimates of many countries, mostly developing countries, for which national emission data are not available. This study demonstrates that in many countries, the mercury content of coal and petroleum locally consumed differ significantly from those locally produced. If the mercury content in locally produced fuels were used to estimate emission, then the resulting global mercury emissions from coal and petroleum would be overestimated by 4.7 and 72%, respectively. Even higher misestimations would exist in individual countries, leading to strong spatial bias. On the basis of the available data on fuel trading and an updated global fuel consumption database, a new mercury emission inventory for 64 combustion sources has been developed. The emissions were mapped at 0.1° × 0.1° resolution for 2007 and at country resolution for a period from 1960 to 2006. The estimated global total mercury emission from all combustion sources (fossil fuel, biomass fuel, solid waste, and wildfires) in 2007 was 1454 Mg (1232-1691 Mg as interquartile range from Monte Carlo simulation), among which elementary mercury (Hg(0)), divalent gaseous mercury (Hg(2+)), and particulate mercury (Hg(p)) were 725, 548, and 181 Mg, respectively. The total emission from anthropogenic sources, excluding wildfires, was 1040 Mg (886-1248 Mg), with coal combustion contributing more than half. Globally, total annual anthropogenic mercury emission from combustion sources increased from 285 Mg (263-358 Mg) in 1960 to 1040 Mg (886-1248 Mg) in 2007, owing to an increased fuel consumption in developing countries. However, mercury emissions from developed countries have decreased since 2000. PMID:24433051

Chen, Yilin; Wang, Rong; Shen, Huizhong; Li, Wei; Chen, Han; Huang, Ye; Zhang, Yanyan; Chen, Yuanchen; Su, Shu; Lin, Nan; Liu, Junfeng; Li, Bengang; Wang, Xilong; Liu, Wenxin; Coveney, Raymond M; Tao, Shu

2014-02-01

255

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

NASA Technical Reports Server (NTRS)

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.

Huntley, S C

1955-01-01

256

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...

257

Effect of degree of fuel vaporization upon emissions for a premixed prevaporized combustion system  

NASA Technical Reports Server (NTRS)

An experimental and analytical study of the combustion of partially vaporized fuel/air mixtures was performed to assess the impact of the degree of fuel vaporization upon emissions for a premixing-prevaporizing flametube combustor. Data collected showed near-linear increases in NOx emmissions with decreasing vaporization at equivalence ratios of 0.6. For equivalence ratios of 0.72, the degree of vaporization had very little impact on NOx emissions. A simple mechanism which accounts for the combustion of liquid droplets in partially vaporized mixtures was found to agree with the measured results with fair accuracy with respect to both trends and magnitudes.

Cooper, L. P.

1979-01-01

258

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

Microsoft Academic Search

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

Michael James Papac

2005-01-01

259

Pyrolysis and Combustion Behavior of Ternary Fuel Blends in Air and Oxy-Fuel Conditions by Using TGA-FTIR  

Microsoft Academic Search

Pyrolysis and combustion tests of imported coal, an indigenous lignite, petcoke, and their 60\\/30\\/10 wt.% ternary blends were carried out in air and oxy-fuel conditions by using thermogravimetry analysis–Fourier transform infrared (TGA-FTIR). Pyrolysis results of the blend and its parent fuels show that weight loss profiles display similar trends up to 700 °C in both nitrogen and carbon dioxide atmospheres. However,

N. S. Yüzba??; N. Selçuk

2012-01-01

260

Synthetic fuel combustion: pollutant formation. Soot initiation mechanisms in burning aromatics. First quarterly report, 19 September31 December 1980  

Microsoft Academic Search

Although considerable progress has been made in recent years in understanding the phenomenology of soot formation in the combustion of hydrocarbon fuels, relatively little attention has been focused upon aromatic fuels of the types commonly found in coal liquids. In particular, the effects of gas-phase free radicals, formed during combustion, on the kinetics of formation of incipient soot particles have

W. T. Rawlins; T. Tanzawa

1981-01-01

261

Modeling of a conceptual self-sustained liquid fuel vaporization – combustion system with radiative output using inert porous media  

Microsoft Academic Search

The present model is based on a combined self-sustained liquid fuel vaporization – combustion system, where the liquid fuel vaporization occurs on a wetted wall plate with energy transferred through the plate from the combustion of vaporized oil. The vaporization energy has been derived through the radiative interaction of the vaporizing plate and an upstream end surface of the porous

Tarun K. Kayal; Mithiles Chakravarty

2007-01-01

262

Combustion of nanofluid fuels with the addition of boron and iron particles at dilute and dense concentrations  

E-print Network

Combustion of nanofluid fuels with the addition of boron and iron particles at dilute and dense in revised form 3 November 2011 Accepted 9 December 2011 Available online 7 January 2012 Keywords: Nanofluid t The combustion characteristics of nanofluid fuels containing additions of boron and iron particles were

Qiao, Li

263

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

Microsoft Academic Search

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

Kirby S. Chapman; Amar Patil

2007-01-01

264

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

NASA Astrophysics Data System (ADS)

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.

Yamamoto, Makoto; Ikeda, Junichi; Inaba, Kazuaki

2006-09-01

265

Combustion stabilization based on a center flame strut in a liquid kerosene fueled supersonic combustor  

NASA Astrophysics Data System (ADS)

A newly designed strut is proposed in this paper for fuel injection and flame holding in a liquid-kerosene-fueled supersonic combustor. The thickness of the strut is 8mm and the front blockage is about 8%. The characteristic of this strut is that extra oxygen can be injected through a set of orifices at the back of the strut, which can change the local flow field structure and ER (Equivalence Ratio). Based on the above mentioned strut, a stable local flame is generated at the back of the strut and the main combustion can be organized around this local fire. Numerical simulation is conducted to compare the local flow field distribution at the back of the strut with/without extra oxygen injection. Experiments are conducted to test the combustion characteristics based on this fuel injection and flame holding strategy. The temperature distribution which can reflect the local flame characteristic has been measured in the experiments conducted under cold incoming supersonic air flow condition. In addition, the overall combustion performance in a full-scale supersonic combustor has been evaluated in the experiments conducted under hot incoming supersonic air flow condition. Results show that this strut strategy is very promising since it can organize stable supersonic combustion at the center of the combustor without any cavity or rearward facing step. Besides that, even with the 8mm thick strut, the combustion can be stable in a wide range of ER from 0.25-1 by using liquid room-temperature kerosene.

Hu, Jichao; Qin, Jiang; Chang, Juntao; Bao, Wen; Zong, Youhai; Yang, Qingchun

2013-10-01

266

Fuel-air mixing and combustion in a two-dimensional Wankel engine  

NASA Technical Reports Server (NTRS)

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.

Shih, T. I.-P.; Schock, H. J.; Ramos, J. I.

1987-01-01

267

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

NASA Technical Reports Server (NTRS)

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.

Frate, David T.; Tofil, Todd A.

2001-01-01

268

Sulphur impacts during pulverised coal combustion in oxy-fuel technology for carbon capture and storage  

Microsoft Academic Search

The oxy-fuel process is one of three carbon capture technologies which supply CO2 ready for sequestration – the others being post-combustion capture and IGCC with carbon capture. As yet no technology has emerged as a clear winner in the race to commercial deployment. The oxy-fuel process relies on recycled flue gas as the main heat carrier through the boiler and

Rohan Stanger; Terry Wall

2011-01-01

269

Development and validation of a combustion model for a fuel cell off-gas burner  

E-print Network

and environmentally clean power generation has never been so important. The increasing cost of fossil fuels and more stringent regulations on emissions (particularly CO2 and NOx), together with increasing demand for electricity, make the provision of cost... Development and Validation of a Combustion Model for a Fuel Cell Off-Gas Burner W. Tristan Collins Magdalene College University of Cambridge A dissertation submitted to the University of Cambridge for the degree of Doctor of Philosophy June 2008...

Collins, William Tristan

2008-10-14

270

Plasma-Assisted Combustion of Gaseous Fuel in Supersonic Duct  

Microsoft Academic Search

The field of plasma-induced ignition and plasma-assisted combustion in high-speed flow is under consideration. Nonequilibrium, unsteady, and nonuniform modes are analyzed as the most promising in reducing a required extra power. Numerical simulations of uniform, nonequilibrium, continuous, and pulse discharge effect on the premixed hydrogen and ethylene-air mixtures in supersonic flow demonstrate an advantage of such a technique over heating.

Sergey B. Leonov; Dmitry A. Yarantsev; Anatoly P. Napartovich; Igor V. Kochetov

2006-01-01

271

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

SciTech Connect

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.

Gerdemann, Stephen J.; Summers, Cathy A.; Oryshchyn, Danylo B.; Patrick, Brian (Jupiter Oxygen Corp.); Ochs, Thomas L.

2005-09-01

272

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

SciTech Connect

Ventilation air methane (VAM) accounts for 60-80% of the total emissions from underground 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. 17 refs., 3 figs., 1 tab.

Changfu You; Xuchang Xu [Tsinghua University, Beijing (China). Key Laboratory for Thermal Science and Power Engineering of Ministry of Education

2008-04-01

273

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

SciTech Connect

One of the most efficient and environmentally compatible coal fueled power generation technologies is the integrated gasification combined cycle (IGCC) concept. Commercialization of the IGCC/HGCU concept requires successful development of combustion systems for high temperature low Btu fuel in gas turbines. Toward this goal, a turbine combustion system simulator has been designed, constructed, and fired with high temperature low Btu fuel. Fuel is supplied by a pilot scale fixed bed gasifier and hot gas desulfurization system. The primary objectives of this project are: (1) demonstration of long term operability of the turbine simulator with high temperature low Btu fuel; (2) measurement of NO{sub x}, CO, and particulate emissions; and (3) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle. In a related project, a reduced scale rich-quench-lean (RQL) gas turbine combustor has been designed, constructed, and fired with simulated low Btu fuel. The overall objective of this project is to develop an RQL combustor with lower conversion of fuel bound nitrogen (FBN) to NO{sub x} than a conventional combustor.

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

1993-11-01

274

Cogeneration system with low NO sub x combustion of fuel gas  

SciTech Connect

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.

Garbo, P.W.

1991-06-25

275

Characteristics of soot emitted from combustion of municipal waste fuels  

SciTech Connect

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.

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

2000-07-01

276

Design of a pyrometer for temperature measurements on the solid fuel combustion chamber  

Microsoft Academic Search

A pyrometer was developed for the measurement of the flame temperature of the solid fuel combustion chamber. The principle of the design is based on the measurement of the spectral intensity at two wavelengths, 577 and 830 nm, emitted by the soot in the flame. The ratio of the intensities is a univocal measure of the color temperature at these

W. J. A. M. Aarts; T. Wijchers

1987-01-01

277

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

Microsoft Academic Search

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

R Albalak; A R Frisancho; G J Keeler

1999-01-01

278

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

E-print Network

Improving the Carbon Dioxide Emission Estimates from the Combustion of Fossil Fuels in California Lawrence Berkeley National Laboratory October, 2008 Contract #05-310 "Improving the Carbon Dioxide Emission-310 "Spatial disaggregated estimate of energy-related carbon dioxide for California" #12;Acknowledgments

279

A synthesis of carbon dioxide emissions from fossil-fuel combustion  

Microsoft Academic Search

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

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

2012-01-01

280

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

EPA Science Inventory

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

281

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...

282

Separation of particulate from flue gas of fossil fuel combustion and gasification  

Microsoft Academic Search

The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical

Wen-Ching Yang; Richard A. Newby; Thomas E. Lippert

1997-01-01

283

Separation of particulate from flue gas of fossil fuel combustion and gasification  

Microsoft Academic Search

The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a

W. C. Yang; R. A. Newby; T. E. Lippert

1997-01-01

284

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...

285

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

NASA Technical Reports Server (NTRS)

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.

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

1958-01-01

286

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....

287

Method and apparatus for regulating the fuel-air ratio in internal combustion engines  

Microsoft Academic Search

A method and an apparatus for regulating the fuel-air ratio of the operational mixture of an internal combustion engine and for monitoring the operational readiness of a lambda sensor controlling the regulating apparatus and functioning according to the principle of ionic conduction in fixed electrolytes. A constant reference voltage which approximately corresponds to the average sensor output voltage is connected

U. Drews; W. Mohrle; P. Werner

1982-01-01

288

Device for regulating the fuel-air ratio in internal combustion engines  

Microsoft Academic Search

A device is proposed for regulating the fuel-air ratio in the operating mixture of an internal combustion engine and for monitoring the operational readiness of a lambda sensor controlling the regulating device and functioning by the principle of ion conduction in solid electrolytes. The lambda sensor has an adjustable, constant reference voltage switched opposite to it. The reference voltage approximately

U. Drews; W. Mohrle; P. Werner

1983-01-01

289

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...

290

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...

291

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

EPA Science Inventory

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

292

Thermal conductivity and combustion properties of wheat gluten foams.  

PubMed

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

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

2012-03-01

293

Enhanced combustion of fossil-fuel particles and droplets in oscillating flow. Annual technical report, 1 September 1978-31 August 1979  

Microsoft Academic Search

The objective of this research is to determine the effect of oscillating flow on the rates of combustion of fossil fuel particles or droplets. Under certain conditions, an oscillatory (pulsating) flow may produce significantly increased rates of burning of fuel particles or droplets and thus provide more effective fuel utilization, with reduced excess air and improved combustion efficiency. The combustion

F. A. Lyman; J. S. Sabnis

1979-01-01

294

Supersonic combustion and mixing characteristics of hydrocarbon fuels in screamjet engines  

NASA Astrophysics Data System (ADS)

The combustion characteristics of gaseous propane in supersonic airflow using the rearward-facing step that is swept inward from both end sides is studied. The effect of sweeping the step on the flow field features of propane combustion is investigated. The study of the supersonic combustion of ethylene is carried out using different combustor configurations, different main fuel equivalence ratios, and different pilot fuel equivalence ratios. The swept step shows the ability to hold the propane flame in the supersonic air stream without extinction. It was found that the side sweeping of the combustor exhibits the high temperature and combustion products concentration in the far field domain while the area downstream of the normal injection location characterizes lower temperature and products concentration. It is recommended to optimize the combustor length to ensure the complete combustion and consequently the full liberation of the chemical energy stored in the fuel before the fuel exits the combustor. The main findings from the ethylene study can be summarized in the following points. The step configuration with no pilot injection can afford the flame holding mechanism in the supersonic air stream by creating the flow recirculations in the step base area and featuring permanent high temperature regions surrounding the normal fuel injection. The step configuration showed good mixing capabilities in the far field domain. The wedge configuration proved superiority over the generic rearward-facing step configuration in holding the ethylene flame in the supersonic airstreams, producing overall higher temperature medium throughout the combustor, and exhibiting lower flow losses and higher combustor efficiency. The increase in the equivalence ratio of the ethylene normal fuel injection enhances the general flow field features and energy field characteristics in the combustor except in the step base area where the lower equivalence ratio features better temperature distribution and higher combustion efficiency. Although the wedge with no pilot injection configuration presents the highest level of temperature distribution in the cavity and downstream regions, the 0.02-pilot equivalence ratio increases the temperature of the upstream face of the normal injection and enhances the flame holding mechanism. The 0.02-pilot equivalence ratio presented the optimum pilot injection case that can promote the flame holding mechanism and keep good combustion and flow field qualities. While further increase of the pilot injection equivalence ratio quenches the high temperature gases in the cavity region, which leads to the deficiency in the flame holding mechanism, the excessive pilot fuel injection shows its positive effect by increasing the average flow field static temperature and absolute pressure in the far field domain. (Abstract shortened by UMI.)

Taha, Ahmed Aly

295

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

SciTech Connect

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.

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

2001-01-01

296

Combustion space modelling of oxy-fuel fired glass melter  

SciTech Connect

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

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

1990-01-01

297

Combustion characteristics of hydrogen. Carbon monoxide based gaseous fuels  

NASA Astrophysics Data System (ADS)

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.

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

1981-10-01

298

Finial Scientific/Technical Report: Application of a Circulating Fluidized Bed Process for the Chemical Looping Combustion of Solid Fuel  

SciTech Connect

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.

Dr. Wei-Ping Pan; Dr. John T. Riley

2005-10-10

299

Combustion properties of coal-char blends: No{sub x} emission characteristics. Technical report, December 1, 1992--February 28, 1993  

SciTech Connect

Tests under pulverized coal combustion conditions suggest that NO{sub x} formed during release of volatile matter far exceed NO{sub x} formed during combustion of the resulting char. This is attributed to char/NO{sub x} interactions by both direct reduction of NO, by carbon and char-catalyzed reduction by CO. This implies combustion of char not only produces substantially lower No{sub x} but the presence of char in the flame during initial stages of combustion may potentially provide catalytic activity for reduction of NO{sub x} produced from volatile nitrogen. The goal of the project is to determine if the concept of NO{sub x} reduction by char/NO{sub x} interactions, while maintaining a high combustion efficiency by co-firing coal with char, is a technically feasible way to reduce NO{sub x} emissions. Char samples will be prepared in a continuous rotary tube kiln under mild gasification conditions. Combustion testing will be conducted with the coal and coal-char blends in a combustor located at BYU. The effect of coal/char ratio, formation characteristics, ignition characteristics, flame stability, and combustion efficiency will be determined. Physical and chemical properties of the fuels will be measured to help explain combustion and emission characteristics of fuels.

Rostam-Abadi, M.; Khan, L. [Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States). Geological Survey; Smoot, L.D.; Germane, G.J.; Eatough, C.N. [Brigham Young Univ., Provo, UT (United States); Honea, F. [Illinois Clean Coal Inst., Carterville, IL (United States)

1993-05-01

300

Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors  

NASA Technical Reports Server (NTRS)

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.

Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

1994-01-01

301

High Speed Optical Diagnostics of Combusting Diesel Fuel Srays  

Microsoft Academic Search

\\u000a Two optical techniques are presented which provide qualitative and semi-quantitative data about the distribution of fuel sprays\\u000a in an optically accessed diesel research engine. The space and time resolved average distribution of fuel sprays is investigated\\u000a with a light extinction method. A dual beam co-axial arrangement using visible and infrared HeNe laser lines identifies spray\\u000a areas containing liquid and vaporized

E. Winklhofer

302

Combustion characteristics of intake port injection type hydrogen fueled engine  

Microsoft Academic Search

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

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

1995-01-01

303

High-density fuel combustion and cooling investigation. [kengine design  

NASA Technical Reports Server (NTRS)

The analysis, design, fabrication and testing of several engine configurations are discussed with respect to the combustion and heat transfer characteristics of LOX/RP-1 at chamber pressures between 6895 and 13790 kPa (1000 and 2000 psia). The different engine configurations discussed include: 8274 kPa and 13790 kPa (1200 psia and 2000 psia) chamber pressure injectors with like doublet and preatomized triplet elements; cooled and uncooled acoustic resonators; and graphite, regeneratively cooled and calorimetric chambers ranging in length from 27.9 to 37.5 cm (11 to 15 in.). A high pressure LOX/RP-1 spark igniter is also evaluated.

Labotz, R. J.; Rousar, D. C.; Valler, H. W.

1980-01-01

304

Mixing fuel particles for space combustion research using acoustics  

NASA Technical Reports Server (NTRS)

Part of the microgravity science to be conducted aboard the Shuttle (STS) involves combustion using solids, particles, and liquid droplets. The central experimental facts needed for characterization of premixed quiescent particle cloud flames cannot be adequately established by normal gravity studies alone. The experimental results to date of acoustically mixing a prototypical particulate, lycopodium, in a 5 cm diameter by 75 cm long flame tube aboard a Learjet aircraft flying a 20 sec low gravity trajectory are described. Photographic and light detector instrumentation combine to measure and characterize particle cloud uniformity.

Burns, Robert J.; Johnson, Jerome A.; Klimek, Robert B.

1988-01-01

305

1 ANNEX 4 IPCC Reference Approach for 2 Estimating CO2 Emissions from Fossil 3 Fuel Combustion  

E-print Network

It is possible to estimate carbon dioxide (CO2) emissions from fossil fuel consumption using alternative methodologies and different data sources than those described in the Estimating Emissions from Fossil Fuel Combustion 7 Annex. For example, the UNFCCC reporting guidelines request that countries, in addition to their “bottom-up ” sectoral 8 methodology, complete a "top-down " Reference Approach for estimating CO2 emissions from fossil fuel combustion.

unknown authors

306

Investigation of sources, properties and preparation of distillate test fuels  

NASA Technical Reports Server (NTRS)

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.

Bowden, J. N.; Erwin, J.

1983-01-01

307

Chemical Kinetic Simulation of the Combustion of Bio-based Fuels  

SciTech Connect

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.

Ashen, Ms. Refuyat [Oak Ridge High School; Cushman, Ms. Katherine C. [Oak Ridge High School

2007-10-01

308

Investigating an annular nozzle on combustion products of hydrocarbon fuels  

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

309

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

NASA Technical Reports Server (NTRS)

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.

Rothrock, A M; Waldron, C D

1933-01-01

310

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

NASA Technical Reports Server (NTRS)

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.

Selden, Robert F

1938-01-01

311

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

NASA Technical Reports Server (NTRS)

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.

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

1977-01-01

312

Numerical simulation of emulsified fuel spray combustion with puffing and micro-explosion  

SciTech Connect

The purpose of this study was to develop numerical simulation of spray combustion of emulsified fuel with considering puffing and micro-explosion. First, a mathematical model for puffing was proposed. In the proposed puffing model, the rate of mass change of a droplet during puffing was expressed by the evaporation rate of dispersed water and the mass change rate due to fine droplets spouted from the droplet surface. The mass change rate due to fine droplets was related to the evaporation rate of the dispersed water and each liquid content. This model had only one experimental parameter. The essential feature of this model was that it was simple to apply to numerical simulation of spray combustion. First, the validity of the proposed puffing model was investigated with the experimental results for a single droplet. The calculated results for a single droplet with the experimental parameter varying from 5.0 to 10 were in good agreement with the experimental results. Moreover, numerical simulation of spray combustion of emulsified fuel was carried out. The occurrence of puffing and micro-explosion was determined by the inner droplet temperature. When micro-explosion occurred, a droplet changed to vapor rapidly. When the proposed puffing model was used in numerical simulation of spray combustion, the experimental parameter in the puffing model was determined for each droplet by random numbers within the range 5.0-10. The calculated results of spray combustion of emulsified fuel without considering puffing or micro-explosions were different from the experimental results even where combustion reactions were almost terminated. Meanwhile, the calculated results when considering puffing and micro-explosions were in good agreement with experimental results at the same location. (author)

Watanabe, Hirotatsu [JSPS Research Fellow, Graduate School of Engineering, Tohoku University 6-6-07 Aoba, Aramaki, Aoba-ku, Sendai 980-8579 (Japan); Matsushita, Yohsuke; Aoki, Hideyuki; Miura, Takatoshi [Department of Chemical Engineering, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba Aramaki, Aoba-ku, Sendai 980-8579 (Japan)

2010-05-15

313

40 CFR 1065.120 - Fuel properties and fuel temperature and pressure.  

Code of Federal Regulations, 2013 CFR

...properties and fuel temperature and pressure. 1065.120 Section 1065...PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...properties and fuel temperature and pressure. (a) Use fuels as...specifies fuel temperature and pressure tolerances and the...

2013-07-01

314

40 CFR 1065.120 - Fuel properties and fuel temperature and pressure.  

Code of Federal Regulations, 2010 CFR

...properties and fuel temperature and pressure. 1065.120 Section 1065...PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...properties and fuel temperature and pressure. (a) Use fuels as...specifies fuel temperature and pressure tolerances and the...

2010-07-01

315

40 CFR 1065.120 - Fuel properties and fuel temperature and pressure.  

Code of Federal Regulations, 2011 CFR

...properties and fuel temperature and pressure. 1065.120 Section 1065...PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...properties and fuel temperature and pressure. (a) Use fuels as...specifies fuel temperature and pressure tolerances and the...

2011-07-01

316

40 CFR 1065.120 - Fuel properties and fuel temperature and pressure.  

Code of Federal Regulations, 2012 CFR

...properties and fuel temperature and pressure. 1065.120 Section 1065...PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS ENGINE-TESTING...properties and fuel temperature and pressure. (a) Use fuels as...specifies fuel temperature and pressure tolerances and the...

2012-07-01

317

Trends of jet fuel demand and properties  

NASA Technical Reports Server (NTRS)

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.

Friedman, R.

1984-01-01

318

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

SciTech Connect

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.

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

1984-01-01

319

Organic combustion fingerprints of three common home heating fuels  

SciTech Connect

The paper discusses the chemical structures of three common home heating 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 'fingerprint' compounds. For wood, where the chief structural element is lignin polymer, they are methoxy benzenes, methoxy phenols, and alkyl bezenes. For coal, where the polymer contains more fused-ring structures, the chief products are fused-ring aromatics with structures of three or more rings, benzothiophenes, and to a lesser extent methyl-substituted phenols. For oil, the chief byproducts are unburned droplets of the oil. The paper concludes with a brief discussion of how these fingerprints can be used as apportionment guides in complex airsheds.

Steiber, R.S.

1993-01-01

320

Correlations of laminar combustion data for alternative SI engine fuels  

SciTech Connect

Most of the spark ignition engine cycle simulations use turbulent burning models which require a knowledge of laminar burning velocity of the fuel-air mixture as a function of mixture strength, unburned mixture temperature and pressure. Burning velocity data of different alternative spark ignition engine fuels obtained by various workers have been compared and critically evaluated. Empirical and semi-empirical correlations, suitable for cycle simulation studies, are presented for laminar burning velocity as a function of mixture strength, unburned mixture temperature, pressure, and residual gas fraction. Fuels considered include ethanol, methanol, alcohol/water blends, isooctane/alcohol blends, propane and isooctane. Experimental data obtained by the present author constitute the major part of the data used in correlations. Published data of other workers and the predictions of theoretical thermo-kinetic models have also been considered in correlations.

Gulder, O.L.

1984-01-01

321

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

SciTech Connect

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.

Koomey, J.

1990-07-01

322

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

NASA Technical Reports Server (NTRS)

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.

Wang, Y.; Gupta, A. K.

2001-01-01

323

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

SciTech Connect

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.

Ochs, Thomas L.; Oryshchyn, Danylo B.; Gross, Dietrich (Jupiter Oxygen Corp.); Patrick, Brian (Jupiter Oxygen Corp.); Gross, Alex (Jupiter Oxygen Corp.); Dogan, Cindy; Summers, Cathy A.; Simmons, William (CoalTeck LLC); Schoenfeld, Mark (Jupiter Oxygen Corp.)

2004-01-01

324

Impact of aviation non-CO? combustion effects on the environmental feasibility of alternative jet fuels.  

PubMed

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

Stratton, Russell W; Wolfe, Philip J; Hileman, James I

2011-12-15

325

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...

326

Combustion of solid fuel slabs with gaseous oxygen in a hybrid motor analog  

NASA Technical Reports Server (NTRS)

Using a high-pressure, two-dimensional hybrid motor, an experimental investigation was conducted on fundamental processes involved in hybrid rocket combustion. HTPB (Hydroxyl-terminated- Polybutadiene) fuel cross linked with diisocyanate was burned with GOX under various operating conditions. Large amplitude pressure oscillations were encountered in earlier test runs. After identifying the source of instability and decoupling the GOX feed line system and combustion chamber, the pressure oscillations were drastically reduced from +/- 20% of the localized mean pressure to an acceptable range of +/- 1.5%. Embedded fine-wire thermocouples indicated that the surface temperature of the burning fuel was around 1000 K depending upon axial locations and operating conditions. Also, except near the leading-edge region, the subsurface thermal wave profiles in the upstream locations arc thicker than those in the downstream locations since the solid-fuel regression rate, in general, increases with distance along the fuel slab. The recovered solid fuel slabs in the laminar portion of the boundary layer exhibited smooth surfaces, indicating the existence of a liquid melt layer on the burning fuel surface in the upstream region. After the transition section, which displayed distinct transverse striations, the surface roughness pattern became quite random and very pronounced in the downstream turbulent boundary-layer region. Both real time X-ray radiography and ultrasonic pulse-echo techniques were used to determine the instantaneous web thicknesses and instantaneous solid-fuel regression rates over certain portions of the fuel slabs. Globally averaged and axially dependent but time-averaged regression rates were also obtained and presented. Several tests were conducted using, simultaneously, one translucent fuel slab and one fuel slab processed with carbon black powder. The addition of carbon black did not affect the measured regression rates or surface temperatures in comparison to the translucent fuel slabs.

Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

1995-01-01

327

Advanced Combustion  

SciTech Connect

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).

Holcomb, Gordon R. [NETL

2013-03-11

328

Combustion  

NSDL National Science Digital Library

In this chemistry activity, learners discover that the weight of the product of combustion is greater than that of the starting material. Learners will compare the weight of steel wool before and after it is heated. Learners are asked to consider why the steel wool weighs more (oxidation) as well as write the balanced chemical equation for the burning of steel. This activity uses an open flame; adult supervision is recommended. The resource includes notes for educators and extension ideas.

House, The S.

2014-01-28

329

EMISSIONS ASSESSMENT FOR REFUSE-DERIVED FUEL COMBUSTION  

EPA Science Inventory

The RDF and coal were burned in a small spreader-stoker fired boiler. The parameters that were varied in this program were RDF type and amount of coal burned with the RDF. In two experiments a waste chemical, triethanolamine, was added to the fuel, and its destruction efficiency ...

330

Pollutant Emissions from Gasoline Combustion. 1. Dependence on Fuel  

E-print Network

predictions of species concentrations in premixed flames of n-heptane, isooctane, benzene, cyclohexane-heptane and isooctane, since paraffins are the dominant constituents of gasoline and kinetic data are readily available fractions that are analytically identifi- able in gasoline fuels, which includes n-heptane (3­5), isooctane

Utah, University of

331

Aircraft Research and Technology for Future Fuels  

NASA Technical Reports Server (NTRS)

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.

1980-01-01

332

Emissions from laboratory combustion of wildland fuels: emission factors and source profiles.  

PubMed

Combustion of wildland fuels represents a major source of particulate matter (PM) and light-absorbing elemental carbon (EC) on a national and global scale, but the emission factors and source profiles have not been well characterized with respect to different fuels and combustion phases. These uncertainties limit the accuracy of current emission inventories, smoke forecasts, and source apportionments. This study investigates the evolution of gaseous and particulate emission and combustion efficiency by burning wildland fuels in a laboratory combustion facility. Emission factors for carbon dioxide (CO2), carbon monoxide (CO), total hydrocarbon (THC), nitrogen oxides (NO(x)), PM, light extinction and absorption cross sections, and spectral scattering cross sections specific to flaming and smoldering phases are reported. Emission factors are generally reproducible within +/- 20% during the flaming phase, which, despite its short duration, dominates the carbon emission (mostly in the form of CO2) and the production of light absorption and EC. Higher and more variable emission factors for CO, THC, and PM are found during the smoldering phase, especially for fuels containing substantial moisture. Organic carbon (OC) and EC mass account for a majority (i.e., > 60%) of PM mass; other important elements include potassium, chlorine, and sulfur. Thermal analysis separates the EC into subfractions based on analysis temperature demonstrating that high-temperature EC (EC2; at 700 degrees C) varies from 1% to 70% of PM among biomass burns, compared to 75% in kerosene soot. Despite this, the conversion factor between EC and light absorption emissions is rather consistent across fuels and burns, ranging from 7.8 to 9.6 m2/g EC. Findings from this study should be considered in the development of PM and EC emission inventories for visibility and radiative forcing assessments. PMID:17626431

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

2007-06-15

333

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

NASA Astrophysics Data System (ADS)

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 ˜2000 K.

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

2012-06-01

334

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

SciTech Connect

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.

Kopyl, P. V.; Surkont, O. S.; Shibkov, V. M.; Shibkova, L. V. [Moscow State University, Faculty of Physics (Russian Federation)

2012-06-15

335

Standard test method for heat of combustion of hydrocarbon fuels by bomb calorimeter (high-precision method)  

SciTech Connect

This method covers the determination of the heat of combustion of hydrocarbon fuels. It is designed specifically for use with aviation turbine fuels when the permissible difference between duplicate determinations is of the order of 0.1%. It can be used for a wide range of volatile and nonvolatile materials where slightly greater differences in precision can be tolerated. The heat of combustion is determined by burning a weighed sample in an oxygen-bomb calorimeter under controlled conditions. The temperature is measured by means of a platinum resistance thermometer. The heat of combustion is calculated from temperature observations before, during, and after combustion, with proper allowance for thermochemical and heat-transfer corrections. Either isothermal or adiabatic calorimeters may be used. The heat of combustion is a measure of the energy available from a fuel. A knowledge of this value is essential when considering the thermal efficiency of equipment for producing either power or heat.

Not Available

1980-01-01

336

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve Timing  

E-print Network

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve engine efficiency. Fuel-flexible engines permit the increased use of ethanol-gasoline blends. Ethanol points across the engine operating range for four blends of gasoline and ethanol. I. INTRODUCTION Fuel

337

Combustion characteristics of hydrogen–hydrocarbon hybrid fuels  

Microsoft Academic Search

A comparative study of the flame structure and characteristics of diffusion flames of the mixture of hydrogen–hydrocarbon (natural gas and propane) hybrid fuel in a slow co-flowing stream of air is presented. The volumetric content of natural gas and propane in the mixture was varied from 0–35%. The burner exit Reynolds number was varied from 150–3000. Measurements include flame length,

Ahsan R Choudhuri; S. R Gollahalli

2000-01-01

338

Numerical Simulation in Combustion Space of an Oxy-fuel Glass Furnace with Different Jet Angles of Auxiliary Oxygen  

Microsoft Academic Search

Numerical simulation in the combustion space of an oxy-fuel glass furnace was carried out. In order to obtain better combustion efficiency, the cases by adding auxiliary oxygen inlet with different jet angles of auxiliary oxygen from 0 degrees to 90 degrees were compared. The gas phase is expressed with two-equation model, while the combustion with non-premixed model and the radiation

Xinjie Fu; Hailiang Zhang; Junlin Xie; Shuxia Mei

2010-01-01

339

Organic combustion fingerprints of three common home heating fuels  

SciTech Connect

The chemical structures of three common home heating fuels are discussed: wood, coal and No.2 fuel oil. GC and GC/MS data and then presented which demonstrate how the thermal destruction of each of these fuels results in the production of a characteristic group of organic compounds. In the case of wood, where the chief structural elements is the lignin polymer, these are the methoxy phenols, the methoxy benzenes, and the alkyl benzenes. In the case of coal, where the polymer contains more fused-ring structures, the chief products are fused-ring aromatics with structures of 3-rings or more, the benzothiophenes, and to a lesser extent the methyl-substituted phenols. In the case of oil, the chief by-products are shown to be unburned droplets of the oil itself. The paper concludes with a brief discussion of how these {open_quotes}fingerprints{close_quotes} might be used as apportionment guides in complex airsheds. 12 refs., 6 figs., 2 tabs.

Steiber, R.S. [Air and Energy Engineering Research Lab., Research Triangle Park, NC (United States)

1993-06-01

340

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

NASA Technical Reports Server (NTRS)

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.

Zimmerman, Frank

2000-01-01

341

Fundamental phenomena on fuel decomposition and boundary layer combustion processes with applications to hybrid rocket motors  

NASA Technical Reports Server (NTRS)

An experimental study on the fundamental processes involved in fuel decomposition and boundary layer combustion in hybrid rocket motors is being conducted at the High Pressure Combustion Laboratory of the Pennsylvania State University. This research should provide an engineering technology base for development of large scale hybrid rocket motors as well as a fundamental understanding of the complex processes involved in hybrid propulsion. A high pressure slab motor has been designed for conducting experimental investigations. Oxidizer (LOX or GOX) is injected through the head-end over a solid fuel (HTPB) surface. Experiments using fuels supplied by NASA designated industrial companies will also be conducted. The study focuses on the following areas: measurement and observation of solid fuel burning with LOX or GOX, correlation of solid fuel regression rate with operating conditions, measurement of flame temperature and radical species concentrations, determination of the solid fuel subsurface temperature profile, and utilization of experimental data for validation of a companion theoretical study also being conducted at PSU.

Kuo, Kenneth K.; Lu, Y. C.; Chiaverini, Martin J.; Harting, George C.

1994-01-01

342

Experimental investigation of electrostatic dispersion and combustion of diesel-fuel jets  

SciTech Connect

An experienced study of electrostatically atomized and dispersed diesel-fuel jets was conducted. A new electrostatic-injection technique was utilized to generate continuous, stable fuel sprays at charge densities of 1.5-2.0 C/cu.m. of fluid. Model calculations show that such charge densities may enhance spray dispersion under diesel-engine conditions. Fuel jets were injected into room temperature air at one atmosphere at flow rates of 0.25-1.0 cc/s and delivery pressures of 100-400 kPa. Measured mean drop diameters were near 150 micro with 30% of the droplets being less than 100 micro in diameter at typical operating conditions. The electrical power required to generate these sprays was less than .000001 times the chemical energy available from the fuel. The spray characteristics of an actual diesel engine injector were also studied. The results show considerable differences in spray characteristics between the diesel injector and electrostatic injection. Finally, ignition and stable combustion of electrostatically dispersed diesel fuel jets was achieved. The results show that electrostatic fuel injection can be achieved at practical flow rates, and that the characteristics of the jet breakup and dispersion have potential application to combustion systems.

Bankston, C.P.; Back, L.H.; Kwack, E.Y.; Kelly, A.J.

1988-07-01

343

A synthesis of carbon dioxide emissions from fossil-fuel combustion  

SciTech Connect

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.

Andres, Robert Joseph [ORNL; Boden, Thomas A [ORNL; Breon, F.-M. [CEA/DSM/LSCE, Gif sur Yvette, France; Ciais, P. [LSCE/CEA, Gif-sur-Yvette, France; Davis, S. [Carnegie Institution of Washington; Erickson, D [Oak Ridge National Laboratory (ORNL); Gregg, J. S. [Riso National Laboratory, Roskilde, Denmark; Jacobson, Andrew [NOAA ESRL and CIRES; Marland, Gregg [Appalachian State University; Miller, J. [NOAA ESRL and CIRES; Oda, T [NOAA ESRL/Boulder, CO/Cooperative Institute for Research in the Atmosphere, Colorado State Univ.; Oliver, J. G. J. [PBL Netherlands Environmental Assessment Agency, Bilthoven, The Netherlands; Raupach, Michael [CSIRO Marine and Atmospheric Research; Rayner, P [University of Melbourne, Australia; Treanton, K. [Energy Statistics Division, International Energy Agency, Paris, France

2012-01-01

344

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

SciTech Connect

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.

Grout, Ray W [ORNL

2012-01-01

345

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

SciTech Connect

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.

Sankaran, R.; Grout, R.

2012-01-01

346

Achieve Continuous Injection of Solid Fuels into Advanced Combustion System Pressures  

SciTech Connect

The overall objective of this project is the development of a mechanical rotary-disk feeder, known as the Stamet Posimetric High Pressure Solids Feeder System, to feed dry granular coal continuously and controllably into pressurized environments of up to 35 kg/cm{sup 2} (500 psi). This was to be accomplished in two phases. The first task was to review materials handling experience in pressurized operations as it related to the target pressures for this project, and review existing coal preparation processes and specifications currently used in advanced combustion systems. Samples of existing fuel materials were obtained and tested to evaluate flow, sealing and friction properties. This provided input data for use in the design of the Stamet Feeders for the project, and ensured that the material specification used met the requirements of advanced combustion & gasification systems. Ultimately, Powder River Basin coal provided by the PSDF facility in Wilsonville, AL was used as the basis for the feeder design and test program. Based on the material property information, a Phase 1 feeder system was designed and built to accomplish feeding the coal to an intermediate pressure up to 21 kg/cm{sup 2} (300 psi) at feed rates of approximately 100 kilograms (220lbs) per hour. The pump & motor system was installed in a custom built test rig comprising an inlet vessel containing an active live-wall hopper mounted in a support frame, transition into the pump inlet, transition from pump outlet and a receiver vessel containing a receiver drum supported on weigh cells. All pressure containment on the rig was rated for the final pressure requirement of 35 kg/cm{sup 2} (500psi). A program of testing and modification was carried out in Stamet's facility in CA, culminating in successful feeding of coal into the Phase 1 target of 21 kg/cm{sup 2} (300psi) gas pressure in December 2003. Further testing was carried out at CQ Inc's facility in PA, providing longer run times and experience of handling and feeding the coal in winter conditions. Based on the data developed through the testing of the Phase I unit, a Phase II system was designed for feeding coal into pressures of up to 35 kg/cm{sup 2} (500 psi). A further program of testing and modification was then carried out in Stamet's facility, with the target pressure being achieved in January 2005. Repeated runs at pressure were achieved, and optimization of the machine resulted in power reductions of 60% from the first successful pressure runs. General design layout of a commercial-scale unit was conducted, and preliminary cost estimates for a commercial unit obtained.

Derek L. Aldred; Timothy Saunders

2005-07-01

347

Fluidized bed combustion of pelletized biomass and waste-derived fuels  

SciTech Connect

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)

Chirone, R.; Scala, F.; Solimene, R. [Istituto di Ricerche sulla Combustione - C.N.R., Piazzale V. Tecchio 80, 80125 Naples (Italy); Salatino, P.; Urciuolo, M. [Dipartimento di Ingegneria Chimica - Universita degli Studi di Napoli Federico II, Piazzale V. Tecchio 80, 80125 Naples (Italy)

2008-10-15

348

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)

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.

Tower, Leonard K; Gammon, Benson E

1953-01-01

349

Metallic elements in fossil fuel combustion: amounts and form of emissions and evaluation of carcinogenicity and mutagenicity  

Microsoft Academic Search

Metallic elements contained in coal, oil and gasoline are mobilized by combustion processes and may be emitted into the atmosphere, mainly as components of submicron particles. The information about the amounts, composition and form of metal compounds is reviewed for some fuels and combustion processes. Since metal compounds are always contained in urban air pollutants, they have to be considered

V. B. Vonk; W. T. Piver

1983-01-01

350

An analytical investigation of primary zone combustion temperatures and NOx production for turbulent jet flames using low-BTU fuels  

E-print Network

The objective of this research project was to identify and determine the effect of jet burner operating variables that influence combustion of low-BTU gases. This was done by simulating the combustion of a low-BTU fuel in a jet flame and predicting...

Carney, Christopher Mark

2012-06-07

351

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

NASA Astrophysics Data System (ADS)

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.

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

2011-09-01

352

Nano crystalline ceria-neodymia solid solutions by combustion route: effect of agglomeration on powder properties.  

PubMed

About 8 compositions in the system Ce(1-x)Nd(x)O(2-x/2) (0.0 < or = x < or = 0.50) were prepared by the combustion process using glycine as a fuel and corresponding metal nitrates as the oxidants. The oxidant-to-fuel ratio was taken as 1:1.0. The products were characterized by X-ray diffraction (XRD), surface area, scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering, sinterability etc. The crystallite size of powders, as obtained by the line broadening method, was typically in the range of 7 to 16 nm. The deagglomeration studies carried out showed that the average agglomerate size of these powders increases with increasing content of Nd in CeO2. The powders were sintered at 1200 degrees C to yield densities in the range of 80-95% of theoretical densities. This wide variation in the sintered density was explained based on the powder properties. An interesting observation was that the nature and size of the agglomerates plays an important role in governing properties such as sintered density and in turn ionic conductivity of nano ceramics. PMID:18019152

Bedekar, Vinila; Tyagi, A K

2007-09-01

353

Combined catalysts for the combustion of fuel in gas turbines  

SciTech Connect

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.

Anoshkina, Elvira V.; Laster, Walter R.

2012-11-13

354

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

SciTech Connect

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.

Taylor, P.H.; Dellinger, B. [Univ. of Dayton, OH (United States). Research Institute; Sidhu, S.K. [and others

1997-06-01

355

Design and implementation of Carbon Monoxide and Oxygen emissions measurement in swirl-stabilized oxy-fuel combustion  

E-print Network

Oxy-fuel combustion in natural gas power generation is a technology of growing interest as it provides the most efficient means of carbon capture. Since all the emissions from these power plants are sequestered, there are ...

Sommer, Andrew (Andrew Zhang)

2013-01-01

356

Trace elements found in the fuel and in-furnace fine particles collected from 80MW BFB combusting solid recovered fuel  

Microsoft Academic Search

The main fine particle (dp<1?m) forming elements found in combustion gases of anthropogenic waste or biomass fired boilers are typically K, Na and Cl, possibly complemented with S. When these are excluded, in solid recovered fuel (SRF) combustion the main elements were found to be: Ba, Br, Cr, Cu, Fe, Pb, Sb, Sn and Zn. Fine particle composition is presented

P. Vainikka; D. Lindberg; A. Moilanen; H. Ollila; M. Tiainen; J. Silvennoinen; M. Hupa

357

Combustion of two-phase hydrocarbon fuel clouds released into the atmosphere  

Microsoft Academic Search

Numerical modeling of the evolution, behavior, and combustion of two-phase hydrocarbon clouds released into the open atmosphere is presented. A Eulerian-Lagrangian model for transient flows of fuel vapor–droplet mixtures is formulated taking into account heat, mass, and momentum exchange between the gaseous and dispersed phases, soot formation, and radiative heat transfer. The calculations are performed for releases of pressure-liquefied propane;

G. M. Makhviladze; J. P. Roberts; S. E. Yakush

1999-01-01

358

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

Microsoft Academic Search

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

W. Permchart; V. I. Kouprianov

2004-01-01

359

What is the fate of CO2 produced by fossil fuel combustion?  

NSDL National Science Digital Library

Students consider why the observed atmospheric CO2 increase rate is only ~60% of the CO2 loading rate due to fossil fuel combustion. They develop a box-model to simulate the atmospheric CO2 increase during the industrial era and compare it to the historic observations of atmospheric CO2 concentrations. The model is then used to forecast future concentrations of atmospheric CO2 during the next century.

Quay, Paul; University of Washington. This activity is hosted by the Science Education Resource Center (SERC) at Carleton College

360

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

PubMed

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

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

2008-09-01

361

The role of fuel preparation in low-emission combustion  

SciTech Connect

The attainment of very low pollutant emissions, in particular oxides of nitrogen (NO{sub x}), from gas turbines is not only of considerable environmental concern but has also become an area of increasing competitiveness between the different engine manufacturers. For stationary engines, the attainment of ultralow NO{sub x} has become the foremost marketing issue. This paper is devoted primarily to current and emerging technologies in the development of ultralow emissions combustors for application to aircraft and stationary engines. Short descriptions of the basic design features of conventional gas turbine combustors and the methods of fuel injection now in widespread use are followed by a review of fuel spray characteristics and recent developments in the measurement and modeling of these characteristics. The main gas-turbine-generated pollutants and their mechanisms of formation are described, along with related environmental risk and various issues concerning emissions regulations and recently enacted legislation for limiting the pollutant levels emitted by both aircraft and stationary engines. The impact so these emissions regulations on combustor and engine design are discussed first in relation to conventional combustors and then in the context of variable-geometry and staged combustors. Both these concepts are founded on emissions reduction by control of flame temperature. Basic approaches to the design of dry low-NO{sub x} and ultralow-NO{sub x} combustors are reviewed.

Lefebvre, A.H. [Purdue Univ., West Lafayette, IN (United States). Thermal Science and Propulsion Center

1995-10-01

362

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

SciTech Connect

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.

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

2011-01-01

363

Experimental-stochastic investigation of the combustion cyclic variability in HSDI diesel engine using ethanol–diesel fuel blends  

Microsoft Academic Search

An experimental investigation is conducted to evaluate the combustion characteristics of a fully instrumented, high-speed, direct injection (HSDI), standard ‘Hydra’ diesel engine, at various loads when using ethanol–diesel fuel blends up to 15% by vol. ethanol. In each test, combustion chamber and fuel injection pressure diagrams of many consecutive cycles were obtained using a specially developed, high-speed, data acquisition and

D. C. Rakopoulos; C. D. Rakopoulos; E. G. Giakoumis; R. G. Papagiannakis; D. C. Kyritsis

2008-01-01

364

Combustion heat release analysis of ethanol or n-butanol diesel fuel blends in heavy-duty DI diesel engine  

Microsoft Academic Search

An experimental study is conducted to evaluate the effects of using blends of diesel fuel with either ethanol in proportions of 5% and 10% or n-butanol in 8% and 16% (by vol.), on the combustion behavior of a fully-instrumented, six-cylinder, turbocharged and after-cooled, heavy duty, direct injection (DI), ‘Mercedes-Benz’ engine installed at the authors’ laboratory. Combustion chamber and fuel injection

D. C. Rakopoulos; C. D. Rakopoulos; R. G. Papagiannakis; D. C. Kyritsis

2011-01-01

365

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

NASA Technical Reports Server (NTRS)

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.

Vezhba, I.

1979-01-01

366

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

SciTech Connect

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.

Jiang, T.L.; Chiang, W.; Jang, S. [Natl Cheng Kung Univ., Tainan, Taiwan (China)

1995-05-01

367

Methods and systems to thermally protect fuel nozzles in combustion systems  

DOEpatents

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.

Helmick, David Andrew; Johnson, Thomas Edward; York, William David; Lacy, Benjamin Paul

2013-12-17

368

Systematic Reduction of Combustion Reaction Mechanisms of common Hydrocarbons and Oxygenated Fuels  

NASA Astrophysics Data System (ADS)

The aim of this work is the development of a numerical technique for the reduction of reaction mechanisms of common hydrocarbon and oxygenated fuels, such as methane, ethylene, propane, methanol and ethanol, using steady-state and partial equilibrium assumptions. Numerical tests are carried to establish the basic chain for each fuel as well as to determine the amount of small products of combustion, whose concentration depends on the turbulent mixing and needs to be controlled due to environmental restrictions. The results are in agreement with data in the literature.

de Bortoli, A. L.; Vaz, F. A.; Lorenzzetti, G. S.; Martins, I.

2010-09-01

369

Low NO sub x heavy fuel combustor concept program. Phase 1A: Combustion technology generation coal gas fuels  

NASA Technical Reports Server (NTRS)

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.

Sherlock, T. P.

1982-01-01

370

Statistical model for combustion of high-metal magnesium-based hydro-reactive fuel  

NASA Astrophysics Data System (ADS)

We investigate experimentally and analytically the combustion behavior of a high-metal magnesium-based hydro-reactive fuel under high temperature gaseous atmosphere. The fuel studied in this paper contains 73% magnesium powders. An experimental system is designed and experiments are carried out in both argon and water vapor atmospheres. It is found that the burning surface temperature of the fuel is higher in water vapor than that in argon and both of them are higher than the melting point of magnesium, which indicates the molten state of magnesium particles in the burning surface of the fuel. Based on physical considerations and experimental results, a mathematical one-dimensional model is formulated to describe the combustion behavior of the high-metal magnesium-based hydro-reactive fuel. The model enables the evaluation of the burning surface temperature, the burning rate and the flame standoff distance each as a function of chamber pressure and water vapor concentration. The results predicted by the model show that the burning rate and the surface temperature increase when the chamber pressure and the water vapor concentration increase, which are in agreement with the observed experimental trends.

Hu, Jian-Xin; Han, Chao; Xia, Zhi-Xun; Huang, Li-Ya; Huang, Xu

2012-12-01

371

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

SciTech Connect

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.

Szybist, James P [ORNL

2008-01-01

372

Structural and electrochemical properties of LiCoO 2 prepared by combustion synthesis  

Microsoft Academic Search

LiCoO2 powders were prepared by combustion synthesis, using metallic nitrates as the oxidant and metal sources and urea as fuel. A small amount of the LiCoO2 phase was obtained directly from the combustion reaction, however, a heat treatment was necessary for the phase crystallization. The heat treatment was performed at the temperature range from 400 up to 700 °C for

E. I. Santiago; A. V. C. Andrade; C. O. Paiva-Santos; L. O. S. Bulhoes

2003-01-01

373

Comparison of combustion properties of native wood species used for fire pots in Korea  

Microsoft Academic Search

In Korean rural homes, wood is used as a fuel in fire pots for cooking and heating. The process of combustion generates products which may be harmful to occupants. This paper investigates the combustion characteristics of four species of Korean native wood using the cone calorimeter (ISO 5660-1). The peak HRR of the Oak at 50kW\\/m2 was 375.7kW\\/m2 in comparison

Yeong-Jin Chung

2010-01-01

374

Flatness-based embedded control of air-fuel ratio in combustion engines  

NASA Astrophysics Data System (ADS)

A nonlinear controller is designed for air-fuel ratio control in combustion engines, making use of differential flatness theory and of the Derivative-free nonlinear Kalman Filter. It is proven that the air-fuel ratio system is a differentially flat one and admits dynamic feedback linearization. Using a change of variables that is based on differential flatness theory it is shown that the air-fuel ratio system can be transformed to the linear canonical form, for which the design of a state feedback controller is easier. Moreover, to compensate for modeling uncertainties and external disturbances the Derivative-free nonlinear Kalman Filter is designed as a disturbance observer. The estimation of the perturbations that effect the air-fuel systems enables their compensation through the inclusion of an additional term in the feedback control law. The efficiency of the proposed nonlinear feedback control scheme is tested through simulation experiments.

Rigatos, Gerasimos; Siano, Pierluigi; Arsie, Ivan

2014-10-01

375

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

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

376

Measurement of fuel mixing and transport processes in gas turbine combustion  

NASA Astrophysics Data System (ADS)

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.

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

2000-07-01

377

Fuel decomposition and boundary-layer combustion processes of hybrid rocket motors  

NASA Technical Reports Server (NTRS)

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.

Chiaverini, Martin J.; Harting, George C.; Lu, Yeu-Cherng; Kuo, Kenneth K.; Serin, Nadir; Johnson, David K.

1995-01-01

378

Recent trends in aviation turbine fuel properties  

NASA Technical Reports Server (NTRS)

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.

Friedman, R.

1982-01-01

379

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

PubMed

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

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

2008-09-01

380

Greenhouse Impact Due to the Use of Combustible Fuels: Life Cycle Viewpoint and Relative Radiative Forcing Commitment  

PubMed Central

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

Palosuo, Taru; Holmgren, Kristina; Savolainen, Ilkka

2008-01-01

381

Effect of fuel properties on the first cycle fuel delivery in a Port Fuel Injected Spark Ignition Engine  

E-print Network

Achieving robust combustion while also yielding low hydrocarbon (HC) emissions is difficult for the first cycle of cranking during the cold start of a Port Fuel Injected (PFI) Spark Ignition (SI) engine. Cold intake port ...

Lang, Kevin R., 1980-

2004-01-01

382

Preliminary investigation of the effects of coal-water slurry fuels on the combustion in GE coal fueled diesel engine (Task 1. 1. 2. 2. 1, Fuels)  

SciTech Connect

In prior work with the coal fired diesel research engine, a necessity to determine the sensitivity of the engine to a wider range of fuels was resolved and included in the R and D Test Plan submitted on 2/9/89. In general, the economic viability and universal acceptance of the commercial engine will be a factor of its ability to tolerate the widest range of source fuels with minimal fuel beneficiation. As detailed in the R and D Test Plan, a preliminary investigation on the effects of coal-water slurry (CWS) fuels on the combustion in a GE single cylinder test engine was conducted. The following conclusions are obtained from this investigation. All the test CWS fuels were successfully burned in the GE engine combustion system. They include: 3 to 15 microns mean particle size; 0.7 to 2.8% ash level; KY Blue Gem and PA Mariana bituminous coal, WY Kemmer and Spring Creek Sub-Bituminous coal; coal beneficiated with physical and chemical processes; two kinds of additives for OTISCA CWS; and burnout is not effected by ash or particle size within the test range. For each kind of CWS fuel, the detail design parameters of the fuel injection system has to be compatible. With sufficiently high fuel injection pressure, the 3 micron mean particle size OTISCA fuel burns faster than the 5 micron ones. For OTISCA fuel, the burn rate using Ammonium Lignosulfonate as additive is faster than using Ammonium Condensed Naphthalene Sulfonate. Appendices contain data on heat release, fuel characterization reports from two laboratories, general engine test data, and particulate size distribution. 3 refs.

Not Available

1990-06-01

383

Study of trajectories and combustion of fuel-oil droplets in the combustion chamber of a power-plant boiler with the use of a mathematical model  

NASA Astrophysics Data System (ADS)

A mathematical model is developed to permit study of the behavior of fuel-oil droplets in a combustion chamber, and results are presented from a computer calculation performed for the 300-MW model TGMP-314P boiler of a power plant.

Enyakin, Yu. P.; Usman, Yu. M.

1987-09-01

384

RADIATIVE PROPERTY MEASUREMENTS OF OXY-FUEL FLAMES  

SciTech Connect

As part of the DOE Existing Plants, Emissions and Capture (EPEC) program, oxy-combustion is being investigated as a method to simplify carbon capture and reduce the parasitic energy penalties associated with separating CO2 from a dilute flue gas. Gas-phase radiation heat transfer in boilers becomes significant when shifting from air-firing to oxycombustion, and must be accurately represented in models. Currently, radiative property data are not widely available in the literature for conditions appropriate to this environment. In order to facilitate the development and validation of accurate oxy-combustion models, NETL conducted a series of studies to measure radiation properties of oxy-fuel flames at adiabatic flame temperatures of 1750 - 1950K, and product molar concentrations ranging from 95% CO2 to 100% steam, determined by equilibrium calculations. Transmission coefficients were measured as a function of wavelength using a mid-IR imaging spectrometer and a blackbody radiation source. Additionally, flame temperatures were calculated using data collected within CO2 and H2O absorption bands. Experimental results were compared to two statistical narrowband models and experimental data from literature sources. These comparisons showed good overall agreement, although differences between the models and experimental results were noted, particularly for the R branch of the 2.7 ?m H2O band.

Clinton R. Bedick; Stephen K. Beer; Kent H. Casleton; Benjamin T. Chorpening; David W. Shaw; M. Joseph Yip

2011-03-01

385

Meat and bone meal as secondary fuel in fluidized bed combustion  

SciTech Connect

Meat and Bone Meal (MBM) was co-fired in a laboratory scale fluidized bed combustion (FBC) apparatus with two coals. Several fuel blends were combusted under different conditions to study how primary fuel substitution by MBM affects flue gas emissions as well as fluidized bed (FB) agglomeration tendency. MBM, being a highly volatile fuel, caused significant increase of CO emissions and secondary air should be used in industrial scale applications to conform to regulations. The high N-content of MBM is moderately reflected on the increase of nitrogen oxides emissions which are reduced by MBM derived volatiles. The MBM ash, mainly containing bone material rich in Ca, did not create any noteworthy desulphurization effect. The observed slight decrease in SO{sub 2} emissions is predominantly attributed to the lower sulphur content in the coal/MBM fuel mixtures. The SEM/EDS analysis of bed material samples from the coal/MBM tests revealed the formation of agglomerates of bed material debris and ash with sizes that do not greatly exceed the original bed inventory and thus not problematic. 37 refs., 9 figs., 3 tabs.

L. Fryda; K. Panopoulos; P. Vourliotis; E. Kakaras; E. Pavlidou [National Technical University of Athens, Athens (Greece). Laboratory of Steam Boilers and Thermal Plants, School of Mechanical Engineering

2007-07-01

386

Effects of compression and expansion ramp fuel injector configuration on scramjet combustion and heat transfer  

NASA Technical Reports Server (NTRS)

A scramjet combustor with four wall-ramp injectors containing Mach-1.7 fuel jets in the base of the ramps was investigated experimentally. During the test program, two swept ramp injector designs were evaluated. One swept-ramp model had 10-deg compression-ramps and the other had 10-deg expansion cavities between flush wall ramps. The scramjet combustor model was instrumented with pressure taps and heat-flux gages. The pressure measurements indicated that both injector configurations were effective in promoting mixing and combustion. Autoignition occurred for the compression-ramp injectors, and the fuel began to burn immediately downstream of the injectors. In tests of the expansion ramps, a pilot was required to ignite the fuel, and the fuel did not burn for a distance of at least two gaps downstream of the injectors. Once initiated, combustion was rapid in this configuration. Heat transfer measurements showed that the heat flux differed greatly both across the width of the combustor and along the length of the combustor.

Stouffer, Scott D.; Baker, N. R.; Capriotti, D. P.; Northam, G. B.

1993-01-01

387

Alarming Oxygen Depletion Caused by Hydrogen Combustion and Fuel Cells and their Resolution by Magnegas$^{TM}$  

E-print Network

We recall that hydrogen combustion does resolve the environmental problems of fossil fuels due to excessive emission of carcinogenic substances and carbon dioxide. However, hydrogen combustion implies the permanent removal from our atmosphere of directly usable oxygen, a serious environmental problem called oxygen depletion, since the combustion turns oxygen into water whose separation to restore the original oxygen is prohibitive due to cost. We then show that a conceivable global use of hydrogen in complete replacement of fossil fuels would imply the permanent removal from our atmosphere of 2.8875x10^7 metric tons O_2/day. Fuel cells are briefly discussed to point out similarly serious environmental problems, again, for large uses. We propose the possibility of resolving these problems by upgrading hydrogen to the new combustible fuel called magnegas^TM, whose chemical structure is composed by the new chemical species of magnecules, whose energy content and other features are beyond the descriptive capacities of quantum chemistry. In fact, magnegas contains up to 50% hydrogen, while having combustion exhaust with: 1) a positive oxygen balance (releasing more oxygen in the exhaust than that used in the combustion); 2) no appreciable carcinogenic or toxic substances; 3) considerably reduced carbon dioxide as compared to fossil fuels; 4) considerably reduced nitrogen oxides; and 5) general reduction of pollutants in the exhaust up to 96% of current EPA standards.

R. M. Santilli

2000-09-04

388

Fuel-Flexible Combustion System for Co-production Plant Applications  

SciTech Connect

Future high-efficiency, low-emission generation plants that produce electric power, transportation fuels, and/or chemicals from fossil fuel feed stocks require a new class of fuel-flexible combustors. In this program, a validated combustor approach was developed which enables single-digit NO{sub x} operation for a future generation plants with low-Btu off gas and allows the flexibility of process-independent backup with natural gas. This combustion technology overcomes the limitations of current syngas gas turbine combustion systems, which are designed on a site-by-site basis, and enable improved future co-generation plant designs. In this capacity, the fuel-flexible combustor enhances the efficiency and productivity of future co-production plants. In task 2, a summary of market requested fuel gas compositions was created and the syngas fuel space was characterized. Additionally, a technology matrix and chemical kinetic models were used to evaluate various combustion technologies and to select two combustor concepts. In task 4 systems analysis of a co-production plant in conjunction with chemical kinetic analysis was performed to determine the desired combustor operating conditions for the burner concepts. Task 5 discusses the experimental evaluation of three syngas capable combustor designs. The hybrid combustor, Prototype-1 utilized a diffusion flame approach for syngas fuels with a lean premixed swirl concept for natural gas fuels for both syngas and natural gas fuels at FA+e gas turbine conditions. The hybrid nozzle was sized to accommodate syngas fuels ranging from {approx}100 to 280 btu/scf and with a diffusion tip geometry optimized for Early Entry Co-generation Plant (EECP) fuel compositions. The swozzle concept utilized existing GE DLN design methodologies to eliminate flow separation and enhance fuel-air mixing. With changing business priorities, a fully premixed natural gas & syngas nozzle, Protoytpe-1N, was also developed later in the program. It did not have the diluent requirements of Prototype-1 and was demonstrated at targeted gas turbine conditions. The TVC combustor, Prototype-2, premixes the syngas with air for low emission performance. The combustor was designed for operation with syngas and no additional diluents. The combustor was successfully operated at targeted gas turbine conditions. Another goal of the program was to advance the status of development tools for syngas systems. In Task 3 a syngas flame evaluation facility was developed. Fundamental data on syngas flame speeds and flame strain were obtained at pressure for a wide range of syngas fuels with preheated air. Several promising reduced order kinetic mechanisms were compared with the results from the evaluation facility. The mechanism with the best agreement was selected for application to syngas combustor modeling studies in Task 6. Prototype-1 was modeled using an advanced LES combustion code. The tools and combustor technology development culminate in a full-scale demonstration of the most promising technology in Task 8. The combustor was operated at engine conditions and evaluated against the various engine performance requirements.

Joel Haynes; Justin Brumberg; Venkatraman Iyer; Jonathan Janssen; Ben Lacy; Matt Mosbacher; Craig Russell; Ertan Yilmaz; Williams York; Willy Ziminsky; Tim Lieuwen; Suresh Menon; Jerry Seitzman; Ashok Anand; Patrick May

2008-12-31

389

Reducing NOx emissions from a biodiesel-fueled engine by use of low-temperature combustion.  

PubMed

Biodiesel is popularly discussed in many countries due to increased environmental awareness and the limited supply of petroleum. One of the main factors impacting general replacement of diesel by biodiesel is NOx (nitrogen oxides) emissions. Previous studies have shown higher NOx emissions relative to petroleum diesel in traditional direct-injection (DI) diesel engines. In this study, effects of injection timing and different biodiesel blends are studied for low load [2 bar IMEP (indicated mean effective pressure)] conditions. The results show that maximum heat release rate can be reduced by retarding fuel injection. Ignition and peak heat release rate are both delayed for fuels containing more biodiesel. Retarding the injection to post-TDC (top dead center) lowers the peak heat release and flattens the heat release curve. It is observed that low-temperature combustion effectively reduces NOx emissions because less thermal NOx is formed. Although biodiesel combustion produces more NOx for both conventional and late-injection strategies, with the latter leading to a low-temperature combustion mode, the levels of NOx of B20 (20 vol % soy biodiesel and 80 vol % European low-sulfur diesel), B50, and B100 all with post-TDC injection are 68.1%, 66.7%, and 64.4%, respectively, lower than pure European low-sulfur diesel in the conventional injection scenario. PMID:19192810

Fang, Tiegang; Lin, Yuan-Chung; Foong, Tien Mun; Lee, Chia-Fon

2008-12-01

390

Multipathway human health risk assessment concerning air emissions from combustion of Orimulsion fuel  

SciTech Connect

A multipathway human health risk assessment was conducted concerning air emissions from the combustion of Orimulsion. Exposure was considered for nearby residents who might be exposed by oral, dermal or inhalation pathways, including ingestion of analytes that may be present in meat and agricultural products from nearby areas. Occupational exposure were evaluated via the same intake pathways, except for potential ingestion of food products. Pathways included airborne exposures, deposition on crops, exposures to soils, and uptake by livestock and plants. Livestock intake included ingestion of analytes retained by plants and inhalation of soil-bound particulates. Analytes of potential concern included compounds identified as combustion products of the orimulsion fuel. Air concentrations of analytes, and the areal distribution of these concentrations resulting from stack emissions, were predicted using transport and deposition models. A worst cast scenario for air and cumulative soil concentrations was considered to represent the entire facility project lifetime (20 years) for dry deposition as well as predicted air concentrations occurring at continuous 100% facility operating capacity. Potential exposures to sulfuric acid mist and lead were shown to be much less than levels protective of human populations. Based upon the airborne emissions estimates and the deposition estimates for other constituents of interest, as well as the strongly conservative estimates of the potential for human intake, local health risks contributed from the combustion of Orimulsion fuel at the facility were judged to be negligible.

Teaf, C.M.; Coleman, R.M.; Manning, M.J.; Covert, D.J.; Phelps, J.L.

1995-12-31

391

Co-Combustion of Refuse Derived Fuel with Anthracites in a CFB Boiler  

NASA Astrophysics Data System (ADS)

Combustion of Refuse derived fuel (RDF) is considered as a priority solution to energy recovery from municipal solid waste (MSW). The co-combustion characteristics of anthracite coals with RDF were determined in the commercial scale Tonghae CFB Power Plant. As the feeding ratio of the RDF to the anthracites increased to 5%, temperature and pressure were not changed in comparison with firing only anthracites. The amount of the required air was reduced due to high O2 content in RDF relative to the anthracites. The emissions of NOx, SOx, HCl and Dioxin were also measured. According to higher mixing ratio of the RDF to the anthracites, SOx, NOx emissions slightly decreased and HCl emissions increased, because RDF has relatively smaller S, N and higher CI than the anthracites. Heavy metals of the fly ash and bottom ash and the dioxin emissions were far below Korean maximum permissible concentration level at incinerator. The results showed that it is of great use and technically possible to co-combustion of RDF with the anthracites by 5% in the form of fuel recovery and energy production in commercial scale CFB boiler.

Kim, Dong-Won; Lee, Jong-Min; Kim, Jae-Sung

392

Aircraft engine and auxiliary power unit emissions from combusting JP-8 fuel  

SciTech Connect

Due to safety considerations and in an effort to standardize Department of Defense fuels, the US Air Force (USAF) replaced the naptha-based JP-4, MIL-T-5624, with the kerosene-based JP-8, MIL-T-83133, as the standard turbine fuel. Although engine emissions from combustion of JP-4 are well documented for criteria pollutants, little information exists for criteria and hazardous air pollutants from combustion of JP-8 fuel. Due to intrinsic differences between these two raw fuels, their combustion products were expected to differ. As part of a broader engine testing program, the Air Force, through the Human Systems Center at Brooks AFB, TX, has contracted to have the emissions characterized from aircraft engines and auxiliary power units (APUs). Criteria pollutant and targeted HAP emissions of selected USAF aircraft engines were quantified during the test program. Emission test results will be used to develop emission factors for the tested aircraft engines and APUs. The Air Force intends to develop a mathematical relationship, using the data collected during this series of tests and from previous tests, to extrapolate existing JP-4 emission factors to representative JP-8 emission factors for other engines. This paper reports sampling methodologies for the following aircraft engine emissions tests: F110-GE-100, F101-GE-102, TF33-P-102, F108-CF-100, T56-A-15, and T39-GE-1A/C. The UH-60A helicopter engine, T700-GE-700, and the C-5A/B and C-130H auxiliary power units (GTCP165-1 and GTCP85-180, respectively) were also tested. Testing was performed at various engine settings to determine emissions of particulate matter, carbon monoxide, nitrogen oxides, sulfur oxides, total hydrocarbon, and selected hazardous air pollutants. Ambient monitoring was conducted concurrently to establish background pollutant concentrations for data correction.

Kimm, L.T. [Armstrong Lab., Brooks AFB, TX (United States); Sylvia, D.A. [Roy F. Weston, Inc., San Antonio, TX (United States); Gerstle, T.C. [Environmental Quality Management, Inc., Cincinnati, OH (United States); Virag, P. [Roy F. Weston, Inc., West Chester, PA (United States)

1997-12-31

393

Potential hazards associated with combustion of bio-derived versus petroleum-derived diesel fuel.  

PubMed

Fuels from renewable resources have gained worldwide interest due to limited fossil oil sources and the possible reduction of atmospheric greenhouse gas. One of these fuels is so called biodiesel produced from vegetable oil by transesterification into fatty acid methyl esters (FAME). To get a first insight into changes of health hazards from diesel engine emissions (DEE) by use of biodiesel scientific studies were reviewed which compared the combustion of FAME with common diesel fuel (DF) for legally regulated and non-regulated emissions as well as for toxic effects. A total number of 62 publications on chemical analyses of DEE and 18 toxicological in vitro studies were identified meeting the criteria. In addition, a very small number of human studies and animal experiments were available. In most studies, combustion of biodiesel reduces legally regulated emissions of carbon monoxide, hydrocarbons, and particulate matter. Nitrogen oxides are regularly increased. Among the non-regulated emissions aldehydes are increased, while polycyclic aromatic hydrocarbons are lowered. Most biological in vitro assays show a stronger cytotoxicity of biodiesel exhaust and the animal experiments reveal stronger irritant effects. Both findings are possibly caused by the higher content of nitrogen oxides and aldehydes in biodiesel exhaust. The lower content of PAH is reflected by a weaker mutagenicity compared to DF exhaust. However, recent studies show a very low mutagenicity of DF exhaust as well, probably caused by elimination of sulfur in present DF qualities and the use of new technology diesel engines. Combustion of vegetable oil (VO) in common diesel engines causes a strongly enhanced mutagenicity of the exhaust despite nearly unchanged regulated emissions. The newly developed fuel "hydrotreated vegetable oil" (HVO) seems to be promising. HVO has physical and chemical advantages compared to FAME. Preliminary results show lower regulated and non-regulated emissions and a decreased mutagenicity. PMID:22871157

Bünger, Jürgen; Krahl, Jürgen; Schröder, Olaf; Schmidt, Lasse; Westphal, Götz A

2012-10-01

394

Critical assessment of thermophysical properties data of combustion gases for calculating the performance of gas turbine  

Microsoft Academic Search

A consistent set of simple equations of the thermodynamic and transport properties of the combustion products have been developed for gas turbine calculations based on the critically evaluated data and on the recent theory. The properties considered are the density, the heat capacity at constant pressure, the enthalpy, the entropy, the viscosity, and the thermal conductivity. The properties of the

N. Masunaga; T. Hoshino; A. Nagashima

1984-01-01

395

A semi-analytical variable property droplet combustion model  

NASA Astrophysics Data System (ADS)

A multizone droplet burn model is developed to account for changes in the thermal and transport properties as a function of droplet radius. The formulation is semi-analytical---allowing for accurate and computationally efficient estimates of flame structure and burn rates. Zonal thermal and transport properties are computed using the Cantera software and pre-tabulated for rapid evaluation during run-time. Model predictions are compared to experimental measurements of burning n-heptane, ethanol and methanol droplets. An adaptive zone refinement algorithm is developed that minimizes the number of zones required to provide accurate estimates of burn time without excess zones. A sensitivity study of burn rate and flame stand-off with far-field oxygen concentration is conducted with comparisons to experimental data. Overall agreement to data is encouraging with errors typically less than 20% for predictions of burn rates, stand-off ratio and flame temperature for the fuels considered. The quiescent quasi-steady solution is extended to a convective transient solution without the need to solve an eigenvalue solution in time. The time history of the burning droplets show good comparison with experimental data. To further decrease computational cost, the source terms for the transient solution are linearized for an explicit time marching solution. An error convergence study was performed to show a time-step independent solution exists at a reasonable Delta t.

Sisti, John

396

Startup and operation of a biomass-fueled combustion turbine commercial demonstration power plant  

SciTech Connect

BIOTEN has designed, built and is operating a full-scale biomass-fueled, combustion turbine, commercial demonstration power plant (CDP) in Red Boiling Springs, Tennessee. This plant will be used to confirm BIOTEN`s commercial plant design and will generate electricity for sale to the Tennessee Valley Authority through the Tri-County Electric Membership Corporation. Sized at 5 MW(e) the plant initially will be fueled by fresh cut sawdust from local sawmills but will later be used to test other forms of biomass fuels in addition to serving as an engine qualification/test station for engines to be used in BIOTEN`s commercial plants. The design, construction and startup of the plant will be reviewed. Preliminary startup testing results will be presented and benchmark operating performance will be discussed in detail. Extrapolation to commercial plant performance expectation will be made.

Rizzie, J.W.; Picker, F.M. [BIOTEN GP, Knoxville, TN (United States); Freve, W.W. Jr. [EUA Service Corp., West Bridgewater, MA (United States)

1996-12-31

397

Comparison of combustion characteristics of ASTM A-1, propane, and natural-gas fuels in an annular turbojet combustor  

NASA Technical Reports Server (NTRS)

The performance of an annular turbojet combustor using natural-gas fuel is compared with that obtained using ASTM A-1 and propane fuels. Propane gas was used to simulate operation with vaporized kerosene fuels. The results obtained at severe operating conditions and altitude relight conditions show that natural gas is inferior to both ASTM A-1 and propane fuels. Combustion efficiencies were significantly lower and combustor pressures for relight were higher with natural-gas fuel than with the other fuels. The inferior performance of natural gas is shown to be caused by the chemical stability of the methane molecule.

Wear, J. D.; Jones, R. E.

1973-01-01

398

Fuel correlations for combustion purposes, a summary of progress within the past fifteen years. Part 1  

SciTech Connect

Over the years, many correlations for fuel properties have been developed at Laval University. The main goal in this was to provide tools to estimate unknown fuel properties form the known values of the density and the viscosity at one temperature and the ASTM D-86 distillation, since these data are easily determined. For liquid fuels the target was set to establish as many fuel properties as possible which could be derived from three measurements (1) the density at 298 K, (2) the ASTM distillation, (3) the fuel viscosity at a single temperature. These correlations have been published piecemeal in the literature or in report form, but not as an ensemble. The objective of the present work is to list the available correlations and indicate their accuracy and applications.

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

1996-12-31

399

Influence of fuel ash composition on high temperature aerosol formation in fixed bed combustion of woody biomass pellets  

Microsoft Academic Search

In this work, the influence of fuel ash composition on high temperature aerosol formation during fixed bed combustion of woody biomass (two wood pellets and one bark pellets) were investigated experimentally in a laboratory reactor and theoretically through chemical equilibrium model calculations. For all fuels, the particle mass size distribution in the PM2.5 region was bimodal, with one fine mode

Henrik Wiinikka; Rikard Gebart; Christoffer Boman; Dan Boström; Marcus Öhman

2007-01-01

400

Life cycle comparison of fuel cell vehicles and internal combustion engine vehicles for Canada and the United States  

Microsoft Academic Search

The objective of this study is to put forward a full analysis of the impact of the difference between the Canadian and American energy realities on the life cycle of fuel cell vehicles and internal combustion engine vehicles. Electricity is a major type of energy used in the transportation sector. Electricity is needed in the production of feedstock of fuel,

Nada Zamel; Xianguo Li

2006-01-01

401

Some special features of combusting the coal-water fuel made of Belarussian brown coals in the fluidized bed  

NASA Astrophysics Data System (ADS)

This paper deals with the special features of combusting the coal-water fuel prepared on the basis of Belarussian brown coals and anthracite culm (Ukraine) in a fluidized bed. The sequence and the duration (calculated from the mathematical model being suggested) of the stages of the combustion of the coal-water fuel depending on the type of source solid fuel and fluidized bed temperature were experimentally confirmed. The temperature and time dependences of the content of sulfur, nitrogen, and carbon oxides in flue gases were studied.

Borodulya, V. A.; Buchilko, E. K.; Vinogradov, L. M.

2014-07-01

402

Investigation of Sooting in Microgravity Droplet Combustion: Fuel-Dependent Effects  

NASA Technical Reports Server (NTRS)

Kumagai and coworkers first performed microgravity droplet combustion experiments [Kumagai, 1957]. The primary goal of these early experiments were to validate simple 'd(sup 2)-law models [Spalding, 1954, Godsave, 1954] Inherent in the 'd(sup 2) -law' formulation and in the scope of the experimental observation is the neglect of sooting behavior. In fact, the influence of sooting has not received much attention until more recent works [Choi et al., 1990; Jackson et al., 1991; Jackson and Avedisian, 1994; Choi and Lee, 1996; Jackson and Avedisian, 1996; Lee et al., 1998]:. Choi and Lee measured soot volume fraction for microgravity droplet flames using full-field light extinction and subsequent tomographic inversion [Choi and Lee, 1996]. In this investigation, soot concentrations were measured for heptane droplets and it was reported that soot concentrations were considerably higher in microgravity compared to the normal gravity flame. It was reasoned that the absence of buoyancy and the effects of thermophoresis resulted in the higher soot concentrations. Lee et al. [1998] performed soot measurement experiments by varying the initial droplet diameter and found marked influence of sooting on the droplet burning behavior. There is growing sentiment that sooting in droplet combustion must no longer be neglected and that "perhaps one of the most important outstanding contributions of (micro)g droplet combustion is the observation that in the absence of asymmetrical forced and natural convection, a soot shell is formed between the droplet surface and the flame, exerting an influence on the droplet combustion response far greater than previously recognized." [Law and Faeth, 1994]. One of the methods that we are exploring to control the degree of sooting in microgravity is to use different fuels. The effect of fuel structure on sooting propensity has been investigated for over-ventilated concentric coflowing buoyant diffusion flames. (Glassman, 1996]. In these investigations, the fuel flowrate was increased until smoke was observed to escape from the "luminous visible flame" [Glassman, 1996]. A total of 29 fuels were used in order to characterize relative sooting propensity. The sooting propensity of a particular fuel was assessed by comparing the flowrates for soot emission from the tip of the flame. It was reported that the sooting tendency for diffusion flames increased for fuels with higher rates of pyrolysis. Randolph and Law [1986 and not 1994] also examined the effect of fuel structure on droplet sooting behavior. In their experiments the droplets were separated from the bulk gas stream and quenched with nitrogen prior to gravimetric measurements. A variety of fuels were studied, namely aromatics, phenyl-alkanes and alkanes. The results were in qualitative agreement with the work of Glassman [1986]. Vander Wal et al. [1994] performed relative soot concentration measurements using laser-induced incandescence for heptane and decane fuel droplets burning under normal-gravity conditions. It was found that soot volume fractions for decane was more than a factor of two larger than that for heptane. Although the normal-gravity investigations have provided some important insights regarding the influence of fuel structure on the sooting behavior of droplet flames, results cannot be easily extrapolated for microgravity studies since increased residence times and thermophoretic effects must be considered in greater detail. Several studies have compared sooting behavior of different fuel droplets burning under microgravity conditions [Card and Choi, 1990; Jackson et al., 1991; Jackson and Avedisian, 1994], however, detailed quantitative results were not provided. In all of these previous studies, the degree of sooting was only visually assessed from an incandescent backlighted image of the soot containing region. Such techniques can provide misleading results regarding sooting behavior [Choi, 1996].

Manzello, Samuel L.; Hua, Ming; Choi, Mun Young

1999-01-01

403

Investigation on the spontaneous combustion of refuse-derived fuels during storage using a chemiluminescence technique.  

PubMed

Refuse-derived fuel (RDF), a high-caloric material, is used by various combustion processes, such as power plants, as alternative fuel. Several explosion accidents, however, possibly initiated by the spontaneous combustion of stored RDF, have been reported in Japan. Therefore the spontaneous combustion of RDF prepared from domestic garbage was investigated using chemiluminescence. RDF samples were heated either under air or under nitrogen for 1, 2, or 4 h at 120 or 140 degrees C and then cooled by an air or nitrogen stream. All RDF samples exhibited chemiluminescence. In air-treated RDF samples (heated and cooled by air), chemiluminescence after ageing was shown to be slightly lower than before ageing, whereas in nitrogen-treated samples (both heated and cooled by nitrogen) chemiluminescence decreased significantly after ageing. When nitrogen was replaced with air during aging, however, a sudden increase of chemiluminescence was observed. On the other hand, when cooling was done with air, chemiluminescence increased. Higher chemiluminescence was also observed during high-temperature treatment. Further experiments on cellulose, one of the major components of domestic garbage, exhibited similar chemiluminescence patterns to those of RDF when treated by the same methods as those used for RDF ageing. Chemiluminescence from cellulose increased significantly when the atmospheric gas was changed from nitrogen to air, suggesting that oxygen in the air promoted the formation of hydroperoxide from cellulose. Therefore, it is hypothesized that cellulose plays an important role in the formation of chemiluminescence from RDF. The formation of chemiluminescence indicated that radicals are formed from RDF by oxidation or thermal degradation at room or atmospheric temperatures and may subsequently lead to spontaneous combustion. PMID:19039070

Matunaga, Atsushi; Yasuhara, Akio; Shimizu, Yoshitada; Wakakura, Masahide; Shibamoto, Takayuki

2008-12-01

404

The influence of oxygen concentration on the combustion of a fuel/oxidizer mixture  

SciTech Connect

The aim of the present study is to investigate the influence of the O{sub 2} concentration on the combustion behaviour of a fuel/oxidizer mixture. The material tested is a ternary mixture of lactose, starch, and potassium nitrate, which has already been used in an attempt to estimate heat release rate using the FM-Global Fire Propagation Apparatus. It provides a well-controlled combustion chamber to study the evolution of the combustion products when varying the O{sub 2} concentration, between air and low oxidizer conditions. Different chemical behaviours have been exhibited. When the O{sub 2} concentration was reduced beyond 18%, large variations were observed in the CO{sub 2} and CO concentrations. This critical O{sub 2} concentration seems to be the limit before which the material only uses its own oxidizer to react. On the other hand, mass loss did not highlight this change in chemical reactions and remained similar whatever the test conditions. This presumes that the oxidation of CO into CO{sub 2} are due to reactions occurring in the gas phase especially for large O{sub 2} concentrations. This actual behaviour can be verified using a simplified flammability limit model adapted for the current work. Finally, a sensitivity analysis has been carried out to underline the influence of CO concentration in the evaluation of heat release rate using typical calorimetric methods. The results of this study provide a critical basis for the investigation of the combustion of a fuel/oxidizer mixture and for the validation of future numerical models. (author)

Biteau, H. [School of Engineering and Electronics, BRE Centre for Fire Safety Engineering, The University of Edinburgh, Edinburgh EH9 3JL (United Kingdom); Institut National de l'Environnement Industriel et des Risques, Parc Technologique Alata, Verneuil en Halatte (France); Fuentes, A. [Institut Universitaire des Systemes Thermiques Industriels (CNRS UMR 6595), Universite de Provence, 13453 Marseille Cedex 13 (France); Marlair, G. [Institut National de l'Environnement Industriel et des Risques, Parc Technologique Alata, Verneuil en Halatte (France); Torero, J.L. [School of Engineering and Electronics, BRE Centre for Fire Safety Engineering, The University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

2010-04-15

405

Effect of fuel nitrogen and hydrogen content on emissions in hydrocarbon combustion  

NASA Technical Reports Server (NTRS)

How the emissions of nitrogen oxides and carbon monoxide are affected by: (1) the decreased hydrogen content and (2) the increased organic nitrogen content of coal derived fuels is investigated. Previous CRT experimental work in a two stage flame tube has shown the effectiveness of rich lean two stage combustion in reducing fuel nitrogen conversion to nitrogen oxides. Previous theoretical work gave preliminary indications that emissions trends from the flame tube experiment could be predicted by a two stage, well stirred reactor combustor model using a detailed chemical mechanism for propane oxidation and nitrogen oxide formation. Additional computations are reported and comparisons with experimental results for two additional fuels and a wide range of operating conditions are given. Fuels used in the modeling are pure propane, a propane toluene mixture and pure toluene. These give hydrogen contents 18, 11 and 9 percent by weight, respectively. Fuel bound nitrogen contents of 0.5 and 1.0 percent were used. Results are presented for oxides of nitrogen and also carbon monoxide concentrations as a function of primary equivalence ratio, hydrogen content and fuel bound nitrogen content.

Bittker, D. A.; Wolfbrandt, G.

1981-01-01

406

Fuels combustion research. Final technical report, 30 September 1991-30 September 1994  

SciTech Connect

The general effort in understanding the oxidation of aromatic components of JP fuels led to the completion of a study of the oxidation of 1-methylnaphthalene, a species known to contribute to soot formation. The results were the first to report detailed oxidation kinetics for any PAH despite the presence of PAH`s in many practical fuels. Results have also been reported on the understanding of aliphatic fuel pyrolysis and oxidation on methyl- cyclohexane (MCH). an endothermic fuel, and its blend with toluene. Sooting diffusion flame experiments have led to the conclusion that under combustion conditions a critical temperature for soot partide nucleation exists irrespective of the fuel species. This study explained why a smoke height occurs. New degradation studies of `liquid` toluene, MCH and toluene/MCH blends have been reported at unique combinations of T and P in a sub/supercritical flow reactor. Nickel partides in the presence of supercritical MCH were found to facilitate the growth of graphitic filaments which could contribute to fuel line clogging. These smooth continuous filaments created under low temperature supercritical conditions are unique in their own right.

Glassman, I.; Brezinsky, K.

1995-01-03

407

A comprehensive evaluation of the influence of air combustion and oxy-fuel combustion flue gas constituents on Hg(0) re-emission in WFGD systems.  

PubMed

This paper evaluates the influence of the main constituents of flue gases from coal combustion (CO2, O2, N2 and water vapor), in air and oxy-fuel combustion conditions on the re-emission of Hg(0) in wet scrubbers. It was observed that the concentration of water vapor does not affect the re-emission of mercury, whereas O2 and CO2 have a notable influence. High concentrations of O2 in the flue gas prevent the re-emission of Hg(0) due to the reaction of oxygen with the metals present in low oxidation states. High concentrations of CO2, which cause a decrease in the pH and the redox potential of gypsum slurries, reduce the amount of Hg(0) that is re-emitted. As a consequence, the high content of CO2 in oxy-fuel combustion may decrease the re-emission of Hg(0) due to the solubility of CO2 in the suspension and the decrease in the pH. It was also found that O2 affects the stabilization of Hg(2+) species in gypsum slurries. The results of this study confirm that the amount of metals present in limestone as well as the redox potential and pH of the slurries in wet desulphurization plants need to be strictly controlled to reduce Hg(0) re-emissions from power plants operating under oxy-fuel combustion conditions. PMID:24887118

Ochoa-González, Raquel; Díaz-Somoano, Mercedes; Martínez-Tarazona, M Rosa

2014-07-15

408

Laboratory characterization of PM emissions from combustion of wildland biomass fuels  

SciTech Connect

Particle emissions from open burning of southwestern (SW) and southeastern (SE) U.S. 17 fuel types during 77 controlled laboratory burns are presented. The fuels include SW 18 vegetation types: ceanothus, chamise/scrub oak, coastal sage scrub, California sagebrush, 19 manzanita, maritime chaparral, masticated mesquite, oak savanna, and oak woodland as 20 well as SE vegetation types: 1-year, 2-year rough, pocosin, chipped understory, 21 understory hardwood, and pine litter. The SW fuels burned at a higher Modified 22 Combustion Efficiency (MCE) than the SE fuels resulting in lower particulate matter 23 (PM) mass emission factor (EF). Particle size distributions for six fuels and particle 24 number emission or all fuels are reported. Excellent mass closure (slope = 1.00, r2=0.94) 25 between ions, metals, and carbon with total weight was obtained. Organic carbon 26 emission factors inversely correlated (= 0.72) with MCE, while elemental carbon (EC) 27 had little correlation with MCE (=0.10). The EC/total carbon (TC) ratio sharply 28 increased with MCE for MCEs exceeding 0.94. The average levoglucosan and total Poly 29 Aromatic Hydrocarbons (PAH) emissions factors ranged from 25-1272 mg/kg fuel and 30 1790-11300 ?g/kg fuel, respectively. No correlation between MCE and emissions of 31 PAHs/levoglucosan was found. Additionally, PAH diagnostic ratios were observed to be 32 poor indicators of biomass burning. Large fuel-type and regional dependency was 33 observed in the emission rates of ammonium, nitrate, fluoride, chloride, sodium, and

Hosseini, SeyedEhsan; Urbanski, Shawn; Dixit, P.; Qi, L.; Burling, Ian R.; Yokelson, Robert; Johnson, Timothy J.; Shrivastava, ManishKumar B.; Jung, H.; Weise, David; Miller, J. Wayne; Cocker, David R.

2013-09-09

409

Uranium–zirconium hydride fuel properties  

Microsoft Academic Search

Properties of the two-phase hydride U0.3ZrH1.6 pertinent to performance as a nuclear fuel for LWRs are reviewed. Much of the available data come from the Space Nuclear Auxiliary Power (SNAP) program of 4 decades ago and from the more restricted data base prepared for the TRIGA research reactors some 3 decades back. Transport, mechanical, thermal and chemical properties are summarized.

D. Olander; Ehud Greenspan; Hans D. Garkisch; Bojan Petrovic

2009-01-01

410

Electrostatic precipitator collection efficiency and trace element emissions from co-combustion of biomass and recovered fuel in fluidized-bed combustion.  

PubMed

Particle and trace element emissions from energy production have continuously been subject to tightening regulations. At the same time, not enough is known on the effect of different combustion processes and different fuels and fuel mixtures on the particle characteristics and particle removal device operation. In this investigation, electrostatic precipitator fractional collection efficiency and trace metal emissions were determined experimentally at a 66 MW biomass-fueled bubbling fluidized-bed combustion plant. The measurements were carried out at the inlet and outlet of the two-field electrostatic precipitator (ESP) at the flue gas temperature of 130-150 degrees C. Two fuel mixtures were investigated: biomass fuel containing 70% wood residue and 30% peat and biomass with recovered fuel containing 70% wood residue, 18% peat, and 12% recovered fuel. The particle mass concentration at the ESP inlet was 510-1400 mg/Nm3. Particle emission at the ESP outlet was 2.3-6.4 mg/Nm3. Total ESP collection efficiency was 99.2-99.8%. Collection efficiency had a minimum in particle size range of 0.1-2 microm. In this size range, collection efficiency was 96-97%. The emission of the trace metals As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Tl, and V was well below the regulation values set by EU directive for waste incineration and co-incineration. PMID:12854728

Lind, Terttaliisa; Hokkinen, Jouni; Jokiniemi, Jorma K; Saarikoski, Sanna; Hillamo, Risto

2003-06-15

411

Advanced Optical Diagnostic Methods for Describing Fuel Injection and Combustion Flowfield Phenomena  

NASA Technical Reports Server (NTRS)

Over the past decade advanced optical diagnostic techniques have evolved and matured to a point where they are now widely applied in the interrogation of high pressure combusting flows. At NASA Glenn Research Center (GRC), imaging techniques have been used successfully in on-going work to develop the next generation of commercial aircraft gas turbine combustors. This work has centered on providing a means by which researchers and designers can obtain direct visual observation and measurements of the fuel injection/mixing/combustion processes and combustor flowfield in two- and three-dimensional views at actual operational conditions. Obtaining a thorough understanding of the chemical and physical processes at the extreme operating conditions of the next generation of combustors is critical to reducing emissions and increasing fuel efficiency. To accomplish this and other tasks, the diagnostic team at GRC has designed and constructed optically accessible, high pressurer high temperature flame tubes and sectar rigs capable of optically probing the 20-60 atm flowfields of these aero-combustors. Among the techniques employed at GRC are planar laser-induced fluorescence (PLIF) for imaging molecular species as well as liquid and gaseous fuel; planar light scattering (PLS) for imaging fuel sprays and droplets; and spontaneous Raman scattering for species and temperature measurement. Using these techniques, optical measurements never before possible have been made in the actual environments of liquid fueled gas turbines. 2-D mapping of such parameters as species (e.g. OH-, NO and kerosene-based jet fuel) distribution, injector spray angle, and fuel/air distribution are just some of the measurements that are now routinely made. Optical imaging has also provided prompt feedback to researchers regarding the effects of changes in the fuel injector configuration on both combustor performance and flowfield character. Several injector design modifications and improvements have resulted from this feedback. Alternate diagnostic methods are constantly being evaluated as to their suitability as a diagnostic tool in these environments. A new method currently under examination is background oriented Schlieren (BOS) for examining the fuel/air mixing processes. While ratioing the Stokes and anti-Stokes nitrogen lines obtained from spontaneous Raman is being refined for temperature measurement. While the primary focus of the GRC diagnostic work remains optical species measurement and flow stream characterization, an increased emphasis has been placed on our involvement in flame code validation efforts. A functional combustor code should shorten and streamline future combustor design. Quantitative measurements of flow parameters such as temperature, species concentration, drop size and velocity using such methods as Raman and phase Doppler anemometry will provide data necessary in this effort.

Locke, Randy J.; Hicks, Yolanda R.; Anderson, Robert C.

2004-01-01

412

Effects of combustion chamber deposit location and composition. [MMT is the antiknock fuel additive methylcyclopentadienylmanganese tricarbonyl  

SciTech Connect

Combustion chamber deposit samples were taken from two vehicles from an octane requirement increase (ORI) fleet and six vehicles from a three-way catalyst (TWC) durability fleet. This selection allowed a comparison of engine type, driving cycle, and the antiknock fuel additive methycyclopentadienylmanganese tricarbonyl (MMT). Selected samples were characterized by quantitative elemental analyses, emission spectroscopy, and by x-ray diffraction. Results of the study are: (1) combustion chamber deposits consist mainly of carbonaceous material with inorganic compounds from both the fuel and the oil; (2) in most cases the H/C ratio is higher for deposits removed from the end gas region; (3) deposits removed from the exhaust valve are almost entirely inorganic compounds, metal phosphates from the oil and manganese oxide if the fuel contains MMT; (4) the cylinder with the highest octane requirement, and hence the first cylinder to knock, cannot be distinguished from the other cylinders by chemical composition of the deposits; (5) cylinders with high oil consumption could be identified by the high concentration of oil inorganics and low concentration of fuel inorganics compared to the other cylinders; (6) differences in deposit composition were observed between engine families and between driving cycles with the same engine family. The source of these differences is believed to be the engine operating conditions but a specific relation has not been established; (7) Mn/sub 3/O/sub 4/ was present in the deposits when MMT was used in the fuel; and (8) deposit accumulation and stabilization involve more than a single mechanism.

Adams, K.M.; Baker, R.E.

1981-03-01

413

Dioxinlike properties of a trichloroethylene combustion-generated aerosol  

Microsoft Academic Search

Conventional chemical analyses of incineration by-products identify compounds of known toxicity but often fail to indicate the presence of other chemicals that may pose health risks. In a previous report, extracts from soot aerosols formed during incomplete combustion of trichloroethylene (TCE) and pyrolysis of plastics exhibited a dioxinlike response when subjected to a keratinocyte assay. To verify this dioxinlike effect,

S. A. Villalobos; M. J. Anderson; D. E. Hinton

1996-01-01

414

Design of a pyrometer for temperature measurements on the solid fuel combustion chamber  

NASA Astrophysics Data System (ADS)

A pyrometer was developed for the measurement of the flame temperature of the solid fuel combustion chamber. The principle of the design is based on the measurement of the spectral intensity at two wavelengths, 577 and 830 nm, emitted by the soot in the flame. The ratio of the intensities is a univocal measure of the color temperature at these wavelengths. The apparatus is small, robust and user friendly. Calibration currents which imitate the output of the detectors are used to control the electronic circuits. The preliminary measuring accuracy between 1400 and 2800 K is about 20 K if the pyrometer is calibrated every 4 months using a qualified tungsten ribbon lamp.

Aarts, W. J. A. M.; Wijchers, T.

1987-10-01

415

NASA broad-specification fuels combustion technology program: Status and description  

NASA Technical Reports Server (NTRS)

The program presented is a contracted effort to evolve and demonstrate the technology required to utilize broad-specification fuels in current and next generation commercial Conventional Takeoff and Landing aircraft engines, and to verify this technology in full-scale engine tests in 1983. The program consists of three phases: Combustor Concept Screening, Combustor Optimization Testing, and Engine Verification Testing. The development and screening of the combustion system designs for the CF6-80 engine and the JT9D-7 engine, respectively, in high-pressure sector test rigs are reported.

Fear, J. S.

1979-01-01

416

Design and manufacturing of a tubular solid oxide fuel cell combustion system  

NASA Astrophysics Data System (ADS)

Solid oxide fuel cell (SOFC) stacks are electrochemical, electrical and thermal devices as well. Today there are different developments of planar and tubular SOFC stacks including their integration in power systems. Any successful stack design must yield to a high efficiency, a good thermal performance, a sufficient power density at market prices for the total system and a good heat management including the integration in combined cycles. A new design of a tubular SOFC combustion system is presented and the actually evaluated possibilities of manufacturing are discussed.

Winkler, W.; Krüger, J.

417

Fuel injector for achieving smokeless combustion reactions at high pressure ratios  

SciTech Connect

This patent describes a hot gas generator. It comprises: a housing including an interior combustion chamber having a diverging interior wall that is generally a surface of revolution; an axially directed opening centered in the wall; an outer, oxidant inlet in the opening and including swirler vanes for introducing into the chamber at the interior wall a swirling, hollow body of oxidant such that centrifugal force will create a diverging hollow body of swirling oxidant on the interior wall; and a central liquid fuel inlet within the opening and the oxidant inlet and generally concentric therewith.

Shekleton, J.R.

1990-07-24

418

The Effect of Fuel and Oil Structure on Hydrocarbon Emissions from Oil Layers during Closed Vessel Combustion  

Microsoft Academic Search

The effects of fuel and oil structure on the product gas emissions from a combustion bomb are studied for various fuel-oil systems. Five oils (a synthetic motor oil, a petroleum-based motor oil, an oxypolypropylene oil, an oxypolyethylene-polypropylene oil, and glycerol) were tested in combination with two fuel blends (ethane-ethanol and ethane-methanol). Gas samples from the reactor were analyzed by gas

ANDREW A. ADAMCZYK; WALTER G. ROTHSCHILD; E. W. KAISER

1985-01-01

419

FUEL-FLEXIBLE GASIFICATION-COMBUSTION TECHNOLOGY FOR PRODUCTION OF H2 AND SEQUESTRATION-READY CO2  

Microsoft Academic Search

It is expected that in the 21st century the Nation will continue to rely on fossil fuels for electricity, transportation, and chemicals. It will be necessary to improve both the thermodynamic efficiency and environmental impact performance of fossil fuel utilization. General Electric Energy and Environmental Research Corporation (GE EER) has developed an innovative fuel-flexible Advanced Gasification-Combustion (AGC) concept to produce

George Rizeq; Janice West; Arnaldo Frydman; Vladimir Zamansky; Linda Denton; Tomasz Wiltowski

2001-01-01

420

The Assessment of Fracture Geometrical Properties on the Performance of Conventional In Situ Combustion  

Microsoft Academic Search

The aim of the present work is to evaluate the effect of fractures geometrical properties such as orientation, density, location, and networking on the conventional fire flooding (CFF) process performance through simulation analysis. Combustion parameters of a fractured low-permeable carbonate heavy oil reservoir in Iran called Kuh-E-Mond (KEM); applied for simulation study and simulator has been validated with KEM combustion

S. M. Fatemi; R. Kharrat; C. Ghotbi

2011-01-01

421

On the rational formulation of alternative fuels: melting point and net heat of combustion predictions for fuel compounds using machine learning methods.  

PubMed

We report the development of predictive models for two fuel specifications: melting points (T(m)) and net heat of combustion (?(c)H). Compounds inside the scope of these models are those likely to be found in alternative fuels, i.e. hydrocarbons, alcohols and esters. Experimental T(m) and ?(c)H values for these types of molecules have been gathered to generate a unique database. Various quantitative structure-property relationship (QSPR) approaches have been used to build models, ranging from methods leading to multi-linear models such as genetic function approximation (GFA), or partial least squares (PLS) to those leading to non-linear models such as feed-forward artificial neural networks (FFANN), general regression neural networks (GRNN), support vector machines (SVM), or graph machines. Except for the case of the graph machines method for which the only inputs are SMILES formulae, previously listed approaches working on molecular descriptors and functional group count descriptors were used to develop specific models for T(m) and ?(c)H. For each property, the predictive models return slightly different responses for each molecular structure. Therefore, models labelled as 'consensus models' were built by averaging values computed with selected individual models. Predicted results were then compared with experimental data and with predictions of models in the literature. PMID:23574496

Saldana, D A; Starck, L; Mougin, P; Rousseau, B; Creton, B

2013-01-01

422

A Combustion Model for the TWA 800 Center-Wing Fuel Tank Explosion  

SciTech Connect

In support of the National Transportation Safety Board investigation of the TWA Flight 800 accident, a combined experimental/computational effort was conducted that focused on quarter-scale testing and simulation of the fuel-air explosion in the Boeing 747 center wing fuel tank. This report summarizes the modeling approach used at Sandia National Laboratories. In this approach approximations are introduced that capture the essential physics associated with turbulent flame propagation in multiple compartment fuel tanks. This model efficiently defines the pressure loading conditions during a jet-fuel air explosion in a fuel tank confinement. Modeling calculations compare favorably with a variety of experimental quarter-scale tests conducted in rigid confinement. The modeling describes well the overpressure history in several geometry configurations. Upon demonstrating a reasonable comparison to experimental observations, a parametric study of eight possible ignition sources is then discussed. Model calculations demonstrate that different loading conditions arise as the location of the ignition event is varied. By comparing the inferred damage and calculated impulses to that seen in the recovered tank, it maybe possible to reduce the number of likely sources. A possible extension of this work to better define tank damage includes coupling the combustion model as a pressure loading routine for structural failure analysis.

Baer, M.R.; Gross, R.J.

1998-10-02

423

Oxides of Nitrogen Emissions from the Combustion of Monodisperse Liquid Fuel Sprays. Ph.D. Thesis  

NASA Technical Reports Server (NTRS)

A study of NO sub x formation in a one dimensional monodisperse spray combustion system, which allowed independent droplet size variation, was conducted. Temperature, NO and NO sub x concentrations were measured in the transition region, encompassing a 26 to 74 micron droplet size range. Emission measurements of hydrocarbons, carbon monoxide, carbon dioxide and oxygen were also made. The equivalence ratio was varied between 0.8 and 1.2 for the fuels used, including methanol, isopropanaol, n-heptane and n-octane. Pyridine and pyrrole were added to n-heptane as nitrogen-containing additives in order to simulate synthetic fuels. Results obtained from the postflame regions using the pure fuels indicate an optimum droplet size in the range of 43 to 58 microns for minimizing NO sub x production. For the fuels examined, the maximum NO sub x reductions relative to the small droplet size limit were about 10 to 20% for lean and 20 to 30% for stoichiometric and rich mixtures. This behavior is attributed to droplet interactions and the transition from diffusive to premixed type of burning. Preflame vaporization controls the gas phase stoichiometry which has a significant effect on the volume of the hot gases surrounding a fuel droplet, where NO sub x is formed.

Sarv, H.

1985-01-01

424

Pilot scale combustion evaluation of waste and alternate fuels: Phase III, final report. Report for February-August 1978  

Microsoft Academic Search

The report gives results of three studies at EPA's Multifuel Test Facility. The first evaluated a distributed-air staging concept for NOx control in pulverized-coal-fired systems. The second evaluated combustion control techniques and NO emissions when firing coal\\/oil mixtures. The third evaluated emissions and combustion characteristics of refuse-derived fuel (RDF) co-fired with either natural gas or pulverized coal.

R. A. Brown; C. F. Busch

1980-01-01

425

Ignition Quality Tester (IQT): An Alternative for Characterizing the Combustion Kinetics of Low Volatility Fuels  

SciTech Connect

The Ignition Quality Tester (IQT) is a constant volume spray combustion system that can be heated and pressurized to conditions that are similar to a diesel engine at top dead center. With no moving parts and the ability to handle low volatility fuels, the IQT can be a bridge between engines and traditional methods for studying chemical kinetics. By comparing experimental data with model predictions, the IQT has been used to validate skeletal kinetic models of ignition. CFD modeling of the IQT using KIVA-3V was used to predict ignition of n-heptane accurately. Operating the IQT in a regime where chemical kinetics dominates (long ignition delays) allowed NTC behavior to be observed for some isomers of heptane. Experimental results with the low volatility fuel heptamethylnonane also show NTC behavior. At long ignition delays, experimental results can be compared with 0-D detailed chemical mechanisms.

Osecky, E.; Bogin, G.; Ratcliff, M.; Luecke, J.; Chen, J. Y.; Zigler, B. T.

2013-01-01

426

Compression and combustion of non-cryogenic targets with a solid thermonuclear fuel for inertial fusion  

NASA Astrophysics Data System (ADS)

Variants of a target with a solid thermonuclear fuel in the form of deuterium-tritium hydrides of light metals for an inertial fusion have been proposed. The laser-pulse-induced compression of non-cryogenic targets, as well as ignition and combustion of such targets, has been examined. The numerical calculations show that, despite a decrease in the caloric content of the fuel and an increase in the energy losses on intrinsic radiation in the target containing deuterium-tritium hydrides of light metals as compared to the target containing deuterium-tritium ice, the non-cryogenic target can ensure the fusion gain sufficient for its use in the energy cycle of a thermonuclear power plant based on the inertial plasma confinement method.

Gus'kov, S. Yu.; Zmitrenko, N. V.; Sherman, V. E.

2013-04-01

427