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1

Gas turbine alternative fuels combustion characteristics  

NASA Astrophysics Data System (ADS)

An experimental investigation was conducted to obtain combustion performance and exhaust pollutant concentrations for specific synthetic hydrocarbon fuels. Baseline comparison fuels used were gasoline and diesel fuel number two. Testing was done over a range of fuel to air mass ratios, total mass flow rates, and input combustion air temperatures in a flame-tube-type gas turbine combustor. Test results were obtained in terms of released heat and combustion gas emission values. The results were comparable to those obtained with the base fuels with variations being obtained with changing operating conditions. The release of carbon particles during the tests was minimal.

Rollbuhler, R. James

1989-02-01

2

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

3

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

4

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

5

Fuel effects on gas turbine combustion systems  

SciTech Connect

The effects of variations in properties and characteristics of liquid hydrocarbon base fuels in gas turbine engine combustors was investigated. Baseline fuels consisted of military specification materials processed from petroleum and shale oil. Experimental fuels were comprised of liquid petroleum blends that were prepared specifically to exhibit desired physical and chemical properties. These fuels were assessed for their influence on ignition and performance characteristics in combustors of the F100, TF30, and J57 (TF33) engines at simulated operating conditions. In general, during relatively short duration tests, combustor ignition and performance became increasingly poorer as fuel quality deviated from specification or historical values.

Mosier, S.A.

1984-01-01

6

Experimental study of gas turbine combustion with elevated fuel temperatures  

NASA Astrophysics Data System (ADS)

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

Wiest, Heather K.

7

Combustion of coal-gas fuels in a staged combustor  

SciTech Connect

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

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

1982-01-01

8

FUEL INTERCHANGEABILITY FOR LEAN PREMIXED COMBUSTION IN GAS TURBINE ENGINES  

SciTech Connect

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

Don Ferguson; Geo. A. Richard; Doug Straub

2008-06-13

9

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

Microsoft Academic Search

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

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

10

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

11

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

E-print Network

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

Bongartz, Dominik

2014-01-01

12

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

...emissions and operations for fuel gas combustion devices and flares. 60.107a Section 60.107a...emissions and operations for fuel gas combustion devices and flares. (a) Fuel gas combustion devices subject to SO2 or H2 S limit and...

2014-07-01

13

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

Code of Federal Regulations, 2013 CFR

...emissions and operations for fuel gas combustion devices and flares. 60.107a Section 60.107a...emissions and operations for fuel gas combustion devices and flares. (a) Fuel gas combustion devices subject to SO2 or H2 S limit and...

2013-07-01

14

Internal combustion engines fueled by natural gashydrogen mixtures  

Microsoft Academic Search

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

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

2004-01-01

15

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

SciTech Connect

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

Not Available

1993-05-01

16

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

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

17

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

18

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

19

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

SciTech Connect

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

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

2012-05-09

20

Combined catalysts for the combustion of fuel in gas turbines  

DOEpatents

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

21

Integration of Evaporative Gas Turbine with Oxy-Fuel Combustion for Carbon Dioxide Capture  

Microsoft Academic Search

This paper studied the integration of Evaporative Gas Turbine (EvGT) cycle with oxy-fuel combustion for CO2 capture. The impact of key parameters on system electrical efficiency, such as the oxygen purity, Water\\/Gas ratio (W\\/G) has been investigated concerning thermal efficiency. The performance of dry recycle and wet recycle also has be analyzed and compared. Simulation results shows that: (1) 97%

Y. Hu; H. Li; J. Yan

2010-01-01

22

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

23

Combustion Products of Petroleum Jet Fuel, a FischerTropsch Synthetic Fuel, and a Biomass Fatty Acid Methyl Ester Fuel for a Gas Turbine Engine  

Microsoft Academic Search

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

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

2011-01-01

24

A study on low NO{sub x} combustion in LBG-fueled 1500 C-class gas turbine  

SciTech Connect

Developing integrated coal gasification combined-cycle systems ensures cost-effective and environmentally sound options for supplying future power generation needs. The reduction of NO{sub x} emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in Integrated Coal Gasification Combined Cycle (IGCC) power generation systems. The coal gasified fuel, which is produced in a coal gasifier of an air-blown entrained-flow type has a calorific value as low as 1/10 of natural gas. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. This study is performed in a 1,500 C-class gas turbine combustor firing low-Btu coal-gasified fuel in IGCC systems. An advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas and to reduce fuel NO{sub x} emissions from the ammonia in the fuel. The main fuel and the combustion air are supplied into a fuel-rich combustion chamber with strong swirl flow and make fuel-rich flame to decompose ammonia into intermediate reactants such as NHi and HCN. The secondary air is mixed with primary combustion gas dilatorily to suppress the oxidation of ammonia reactants in fuel-lean combustion chamber and to promote a reducing process to nitrogen. By testing under atmospheric pressure conditions, the authors have obtained a very significant result through investigating the effect of combustor exit gas temperature on combustion characteristics. Since they have ascertained the excellent performance of the tested combustor through their extensive investigation, they wish to report on the results.

Nakata, T. [Tohoku Univ., Sendai, Miyagi (Japan). Dept. of Aeronautics and Space Engineering; Sato, M.; Ninomiya, T.; Hasegawa, T. [Central Research Inst. of Electric Power Industry, Yokosuka, Kanagawa (Japan)

1996-07-01

25

Polycyclic aromatic hydrocarbon emissions from the combustion of alternative fuels in a gas turbine engine.  

PubMed

We report on the particulate-bound polycyclic aromatic hydrocarbons (PAH) in the exhaust of a test-bed gas turbine engine when powered by Jet A-1 aviation fuel and a number of alternative fuels: Sasol fully synthetic jet fuel (FSJF), Shell gas-to-liquid (GTL) kerosene, and Jet A-1/GTL 50:50 blended kerosene. The concentration of PAH compounds in the exhaust emissions vary greatly between fuels. Combustion of FSJF produces the greatest total concentration of PAH compounds while combustion of GTL produces the least. However, when PAHs in the exhaust sample are measured in terms of the regulatory marker compound benzo[a]pyrene, then all of the alternative fuels emit a lower concentration of PAH in comparison to Jet A-1. Emissions from the combustion of Jet A-1/GTL blended kerosene were found to have a disproportionately low concentration of PAHs and appear to inherit a greater proportion of the GTL emission characteristics than would be expected from volume fraction alone. The data imply the presence of a nonlinear relation between fuel blend composition and the emission of PAH compounds. For each of the fuels, the speciation of PAH compounds present in the exhaust emissions were found to be remarkably similar (R(2) = 0.94-0.62), and the results do provide evidence to support the premise that PAH speciation is to some extent indicative of the emission source. In contrast, no correlation was found between the PAH species present in the fuel with those subsequently emitted in the exhaust. The results strongly suggests that local air quality measured in terms of the particulate-bound PAH burden could be significantly improved by the use of GTL kerosene either blended with or in place of Jet A-1 kerosene. PMID:22534092

Christie, Simon; Raper, David; Lee, David S; Williams, Paul I; Rye, Lucas; Blakey, Simon; Wilson, Chris W; Lobo, Prem; Hagen, Donald; Whitefield, Philip D

2012-06-01

26

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

27

Effect of pressure on combustion characteristics in LBG-fueled 1,300 C-class gas turbine  

SciTech Connect

Developing integrated coal gasification combined cycle systems ensures that Japan will have cost-effective and environmentally sound options for supplying future power generation needs. Reduction of NO[sub x] emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in IGCC. The coal gasified fuel, which is produced in a coal gasifier of air blown entrained-flow type has a calorific value as low as 1/10 of natural gas. Furthermore, the fuel gas contains ammonia when a gas cleaning system is a hot type, and ammonia will be converted to nitrogen oxides in the combustion process of a gas turbine. The study is performed in 1,300 C-class gas turbine combustor firing coal-gasifier fuel in IGCC power generation systems. In the previous study the advanced rich-lean combustor of 150-MW class gas turbine was designed to hold stable combustion burning low-Btu gas fuel and to reduce fuel NO[sub x] emission that is produced from the ammonia in the fuel. By testing it under atmospheric pressure conditions, they have studied the effects of fuel parameters on combustor performances and listed the basic data for development applications. In this study, by testing it under pressurized conditions, they have obtained a very significant result through investigating the effect of pressure on combustion characteristics and wish to provide herein a summary of their findings.

Nakata, T. (Tohoku Univ., Sendai (Japan). Dept. of Aeronautics and Space Engineering); Sato, M.; Ninomiya, T. (Central Research Inst. of Electric Power Industry, Yokosuka (Japan)); Yoshine, T.; Yamada, M. (Toshiba Corp., Yokohama (Japan). Heavy Apparatus Engineering Lab.)

1994-07-01

28

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

DOEpatents

The gas from combustion or gasification of fossil fuel contains flyash and other particulate. The flyash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The flyash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured flyash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled.

Yang, Wen-Ching (Murrysville, PA); Newby, Richard A. (Pittsburgh, PA); Lippert, Thomas E. (Murrysville, PA)

1997-01-01

29

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

DOEpatents

The gas from combustion or gasification of fossil fuel contains fly ash and other particulates. The fly ash is separated from the gas in a plurality of standleg moving granular-bed filter modules. Each module includes a dipleg through which the bed media flows into the standleg. The bed media forms a first filter bed having an upper mass having a first frusto-conical surface in a frusto-conical member at the entrance to the standleg and a lower mass having a second frusto-conical surface of substantially greater area than the first surface after it passes through the standleg. A second filter media bed may be formed above the first filter media bed. The gas is fed tangentially into the module above the first surface. The fly ash is captured on the first frusto-conical surface and within the bed mass. The processed gas flows out through the second frusto-conical surface and then through the second filter bed, if present. The bed media is cleaned of the captured fly ash and recirculated to the moving granular bed filter. Alternatively, the bed media may be composed of the ash from the combustion which is pelletized to form agglomerates. The ash flows through the bed only once; it is not recycled. 11 figs.

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

1997-08-05

30

NO x emission and performance data for a hydrogen fueled internal combustion engine at 1500 rpm using exhaust gas recirculation  

Microsoft Academic Search

This paper describes six experiments conducted on a 2-liter, 4-cylinder Ford ZETEC internal combustion engine developed to operate on hydrogen fuel. The experiments were conducted to ascertain the effect exhaust gas recirculation (EGR) and a standard 3-way catalytic converter had on NOx emissions and engine performance. All the experiments were conducted at a constant engine speed of 1500rpm and each

James W Heffel

2003-01-01

31

NO x emission reduction in a hydrogen fueled internal combustion engine at 3000 rpm using exhaust gas recirculation  

Microsoft Academic Search

This paper describes five experiments conducted on a 2-l, 4-cylinder Ford ZETEC internal combustion engine (ICE) developed to operate on hydrogen fuel. The experiments were conducted to ascertain the effect exhaust gas recirculation (EGR) and a standard 3-way catalytic converter had on NOx emissions and engine performance. All the experiments were conducted at a constant engine speed of 3000 rpm

James W Heffel

2003-01-01

32

Integrated gas dynamic computational modelling and thermodynamic combustion diagnostics of multicylinder four-stroke spark ignition engine using compressed natural gas as a fuel  

Microsoft Academic Search

A comprehensive computational simulation model has been developed to describe the performance, efficiency and emission characteristics of the four-stroke multi-cylinder spark ignition engine which uses compressed natural gas as a fuel. This model performs an integrated simulation of thermodynamic, gas dynamic, and chemical kinetics of the whole engine system coupling with intake and exhaust manifolds. The thermodynamic combustion process is

J. V. Tirkey; H. N. Gupta; S. K. Shukla

2010-01-01

33

Modeling the effects of auxiliary gas injection and fuel injection rate shape on diesel engine combustion and emissions  

NASA Astrophysics Data System (ADS)

The effect of auxiliary gas injection and fuel injection rate-shaping on diesel engine combustion and emissions was studied using KIVA a multidimensional computational fluid dynamics code. Auxiliary gas injection (AGI) is the injection of a gas, in addition to the fuel injection, directly into the combustion chamber of a diesel engine. The objective of AGI is to influence the diesel combustion via mixing to reduce emissions of pollutants (soot and NO x). In this study, the accuracy of modeling high speed gas jets on very coarse computational grids was addressed. KIVA was found to inaccurately resolve the jet flows near walls. The cause of this inaccuracy was traced to the RNG k - ? turbulence model with the law-of-the-wall boundary condition used by KIVA. By prescribing the lengthscale near the nozzle exit, excellent agreement between computed and theoretical jet penetration was attained for a transient gas jet into a quiescent chamber at various operating conditions. The effect of AGI on diesel engine combustion and emissions was studied by incorporating the coarse grid gas jet model into a detailed multidimensional simulation of a Caterpillar 3401 heavy-duty diesel engine. The effects of AGI timing, composition, amount, orientation, and location were investigated. The effects of AGI and split fuel injection were also investigated. AGI was found to be effective at reducing soot emissions by increasing mixing within the combustion chamber. AGI of inert gas was found to be effective at reducing emissions of NOx by depressing the peak combustion temperatures. Finally, comparison of AGI simulations with experiments were conducted for a TACOM-LABECO engine. The results showed that AGI improved soot oxidation throughout the engine cycle. Simulation of fuel injection rate-shaping investigated the effects of three injection velocity profiles typical of unit-injector type, high-pressure common-rail type, and accumulator-type fuel injectors in the Caterpillar 3401 heavy-duty diesel engine. Pollutant emissions for the engine operating with different injection velocity profiles reflected the sensitivity of diesel engines to the location of pollutants within the combustion chamber, as influenced by the fuel injection.

Mather, Daniel Kelly

1998-11-01

34

Method for combustion of gaseous fuels and flue gases  

Microsoft Academic Search

The invention discloses a method for combustion of gaseous fuels and flue gases in which the heat content of the combustion products is partially recycled to the combustion process by heat exchange with combustion air and\\/or gas, and air and gas are fed to a reaction chamber, where a surface combustion takes place separating air and gas regions, and the

1979-01-01

35

CONCEPTUAL STUDIES OF A FUEL-FLEXIBLE LOW-SWIRL COMBUSTION SYSTEM FOR THE GAS TURBINE IN CLEAN COAL POWER PLANTS  

SciTech Connect

This paper reports the results of preliminary analyses that show the feasibility of developing a fuel flexible (natural gas, syngas and high-hydrogen fuel) combustion system for IGCC gas turbines. Of particular interest is the use of Lawrence Berkeley National Laboratory's DLN low swirl combustion technology as the basis for the IGCC turbine combustor. Conceptual designs of the combustion system and the requirements for the fuel handling and delivery circuits are discussed. The analyses show the feasibility of a multi-fuel, utility-sized, LSI-based, gas turbine engine. A conceptual design of the fuel injection system shows that dual parallel fuel circuits can provide range of gas turbine operation in a configuration consistent with low pollutant emissions. Additionally, several issues and challenges associated with the development of such a system, such as flashback and auto-ignition of the high-hydrogen fuels, are outlined.

Smith, K.O.; Littlejohn, David; Therkelsen, Peter; Cheng, Robert K.; Ali, S.

2009-11-30

36

Modeling of combustion instabilities and their active control in a gas fueled combustor  

Microsoft Academic Search

This study deals with the development of simplified models for simulation of combustion instabilities and their active control. Modulation of a part of the fuel supply is used to damp instabilities by generating heat release oscillations that are out of phase with the existing pressure oscillations. A model that accounts for mixing using a heuristic source term has been developed,

Rajendran Mohanraj

1998-01-01

37

A Technical Review of Compressed Natural Gas as an Alternative Fuel for Internal Combustion Engines  

Microsoft Academic Search

Natural gas is promising alternative fuel to meet strict engine emission regulations in many countries. Compressed natural gas (CNG) has long been used in stationary engines, but the application of CNG as a transport engines fuel has been conside rably advanced over the last decade by the development of lightweight high-pressure storage cy linders. Engine conversion technology is well established

Rosli Abu Bakar

2008-01-01

38

A study on low NO combustion in LBG-fueled 1500 C-class gas turbine  

Microsoft Academic Search

Developing integrated coal gasification combined-cycle systems ensures cost-effective and environmentally sound options for supplying future power generation needs. The reduction of NO emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in Integrated Coal Gasification Combined Cycle (IGCC) power generation systems. The coal gasified fuel, which is produced in a coal

T. Nakata; M. Sato; T. Ninomiya; T. Hasegawa

1996-01-01

39

Superheated fuel injection for combustion of liquid-solid slurries  

Microsoft Academic Search

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

Robben

1984-01-01

40

Superheated fuel injection for combustion of liquid-solid slurries  

Microsoft Academic Search

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

Robben

1985-01-01

41

Emission characterization and evaluation of natural gas-fueled cogeneration microturbines and internal combustion engines  

Microsoft Academic Search

The increasing diffusion of small-scale energy systems within the distributed generation (DG) paradigm is raising the need for studying the environmental impact due to the different DG solutions in order to assess their sustainability. Addressing the environmental impact calls for building specific models for studying both local and global emissions. In this framework, the adoption of natural gas-fueled DG cogeneration

Aldo Canova; Gianfranco Chicco; Giuseppe Genon; Pierluigi Mancarella

2008-01-01

42

Combustion Characteristics and Performance of Low-Swirl Injectors with Natural Gas and Alternative Fuels At Elevated Pressures and Temperatures  

NASA Astrophysics Data System (ADS)

Stationary power-generating gas turbines in the United States have historically been fueled with natural gas, but due to its increasing price and the need to reduce carbon emissions, interest in alternative fuels is increasing. In order to effectively operate engines with these fuels their combustion characteristics need be well understood, especially at elevated pressures and temperatures. In this dissertation, the performance of blends of natural gas / methane with hydrogen and carbon dioxide, to simulate syngas and biogas, are evaluated in a model low-swirl stabilized combustor inside an optically accessible high-pressure vessel. The flashback and lean blow out limits, along with pollutant emissions, flow field, and turbulent displacement flame speeds, are measured as a function of fuel composition, pressure, inlet temperature, firing temperature, and flow rate in the range from 1 to 8 atm, 294 to 600K, 1350 to 1950K, and 20 to 60 m/s, respectively. These properties are quantified as a function of the inlet parameters. The lean blow-out limits are independent of pressure and inlet temperature but are weakly dependent on velocity. NOX emissions for both fuels were found to be exponentially dependent upon firing temperature, but emissions for the high-hydrogen flames were consistently higher than those of natural gas flames. The flashback limits for a 90%/10% (by volume) hydrogen/methane mixture increase with velocity and inlet temperature, but decrease with pressure. Correspondingly, the flame position progresses toward the combustor nozzle with increasing pressure and flame temperature, but away with increasing inlet temperature and velocity. Flashback occurred when the leading edge of the flame entered the nozzle. Local displacement turbulent flame speeds scale linearly with the turbulent fluctuating velocities, u', at the leading edge of the flame. Turbulent flame speeds for high-hydrogen fuels are twice that of natural gas for the same inlet conditions. The results from this study demonstrate the feasibility of using low-swirl combustors as a means to achieve robust, fuel flexible, and low emissions gas turbines in the future. The correlations and design guides developed with the data from this work will aid engineers by providing insight into the performance and optimization of low-swirl stabilized combustors.

Beerer, David Joseph

43

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

SciTech Connect

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, CNG engine performance can be substantially improved in the lean operating region. Lean operation has a number of benefits, the most notable of which is reduced emissions. However, the extremely low flame propagation velocities of CNG greatly restrict the lean operating limits of CNG engines. Hydrogen, however, has a high flame speed and a wide operating limit that extends into the lean region. The addition of hydrogen to a CNG engine makes it a viable and economical method to significantly extend the lean operating limit and thereby improve performance and reduce emissions. Drawbacks of hydrogen as a fuel source, however, include lower power density due to a lower heating value per unit volume as compared to CNG, and susceptibility to pre-ignition and engine knock due to wide flammability limits and low minimum ignition energy. Combining hydrogen with CNG, however, overcomes the drawbacks inherent in each fuel type. Objectives of the current study were to evaluate the feasibility of using blends of hydrogen and natural gas as a fuel for conventional natural gas engines. The experiment and data analysis included evaluation of engine performance, efficiency, and emissions along with detailed in-cylinder measurements of key physical parameters. This provided a detailed knowledge base of the impact of using hydrogen/natural gas blends. A four-stroke, 4.2 L, V-6 naturally aspirated natural gas engine coupled to an eddy current dynamometer was used to measure the impact of hydrogen/natural gas blends on performance, thermodynamic efficiency and exhaust gas emissions in a reciprocating four stroke cycle engine. The test matrix varied engine load and air-to-fuel ratio at throttle openings of 50% and 100% at equivalence ratios of 1.00 and 0.90 for hydrogen percentages of 10%, 20% and 30% by volume. In addition, tests were performed at 100% throttle opening, with an equivalence ratio of 0.98 and a hydrogen blend of 20% to further investigate CO emission variations. Data analysis indicated that the use of hydrogen/natural gas fuel blend penalizes the engine operation with a 1.5 to 2.0% decrease in torque, but provided up to a 36% reduction in CO, a 30% reduction in NOX, and a 5% increase in brake thermal efficiency. These results concur with previous results published in the open literature. Further reduction in emissions can be obtained by retarding the ignition timing.

Kirby S. Chapman; Amar Patil

2007-06-30

44

Combustion engine for solid and liquid fuels  

NASA Technical Reports Server (NTRS)

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

Pabst, W.

1986-01-01

45

Effect of degree of fuel vaporization upon emissions for a premixed partially vaporized combustion system. [for gas turbine engines  

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 in this study showed near linear increases in nitric oxide emissions with decreasing vaporization at equivalence ratios of 0.6. For equivalence ratios of 0.72, the degree of vaporization had very little impact on nitric oxide emissions. A simple mechanism which accounts for the combustion of liquid droplets in partially vaporized mixtures was found to agree with the measured results with fair accuracy with respect to both trends and magnitudes.

Cooper, L. P.

1980-01-01

46

BURNER DESIGN CRITERIA FOR NOX CONTROL FROM LOW-BTU GAS COMBUSTION: VOLUME II. ELEVATED FUEL TEMPERATURE  

EPA Science Inventory

The report gives results of a program to provide quantitative data on combustion emissions from high-temperature low-Btu gas. It complements a recently completed EPA project that evaluated emissions resulting from the burning of ambient-temperature low-Btu gas. The experimental r...

47

EVALUATION OF THE ACCEPTABILITY OF NATURAL GAS AS A MITIGATING FUEL FOR UTILITY COMBUSTION SOURCES  

EPA Science Inventory

The paper gives preliminary findings of a joint EPA/Gas Research Institute study of methane (CH4) loss from the U.S. natural gas industry. he study, not scheduled for completion until 1992, is part of an effort to resolve the issue of CN4 emissions from natural gas production and...

48

Combustion engineering issues for solid fuel systems  

SciTech Connect

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

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

2008-05-15

49

Combustion-gas recirculation system  

DOEpatents

A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

Baldwin, Darryl Dean (Lacon, IL)

2007-10-09

50

DISCRIMINATION OF COMBUSTION FUEL SOURCES USING GAS CHROMATOGRAPY-PLANAR FIELD ASYMETRIC WAVEFORM ION MOBILITY SPECTROMETRY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Smoke plumes from cotton, paper, grass and cigarettes and emissions from a gasoline engine were sampled using solid-phase microextraction (SPME) and samples were analyzed for volatile organic compounds(VOC) using gas chromatography-mass spectrometry (GC-MS). Chemical compositions were sufficiently ...

51

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

52

Life cycle assessment of greenhouse gas emissions and non-CO? combustion effects from alternative jet fuels  

E-print Network

The long-term viability and success of a transportation fuel depends on both economic and environmental sustainability. This thesis focuses specifically on assessing the life cycle greenhouse gas (GHG) emissions and non-CO ...

Stratton, Russell William

2010-01-01

53

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

54

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

55

The effects of spark ignition parameters on the lean burn limit of natural gas combustion in an internal combustion engine  

E-print Network

A full factorial experiment was conducted to determine the effects of internal combustion engine ignition parameters on the air-fuel ratio (A/F) lean limit of combustion with compressed natural gas (CNG). Spark electrical characteristics (voltage...

Chlubiski, Vincent Daniel

1997-01-01

56

Effect of pressure on combustion characteristics in LBG-fueled 1,300 C-class gas turbine  

Microsoft Academic Search

Developing integrated coal gasification combined cycle systems ensures that Japan will have cost-effective and environmentally sound options for supplying future power generation needs. Reduction of NO[sub x] emissions and increasing the inlet temperature of gas turbines are the most significant issues in gas turbine development in IGCC. The coal gasified fuel, which is produced in a coal gasifier of air

T. Nakata; M. Sato; T. Ninomiya; T. Yoshine; M. Yamada

1994-01-01

57

Controlling fuel and diluent gas flow for a diesel engine operating in the fuel rich low-temperature-combustion mode  

E-print Network

The flow of a diluent gas supplied to a motoring engine was controlled at a diluent to air mass flow ratios of 10%, 30%, 50%, and 70%. This arrangement was a significant set up for running the engine in the Low-Temperature ...

Lopez, David M

2007-01-01

58

Variability in natural gas fuel composition and its effects on the performance of catalytic combustion systems. Final report for period September 18, 1998 - September 17, 2000  

SciTech Connect

Natural gas is composed primarily of methane with small amounts of higher hydrocarbons and diluents, which vary by region and over time. Compositions of natural gas from domestic and worldwide sources were surveyed with respect to content of higher hydrocarbons and diluents. The survey showed slight compositional variability between most of the gases, with a small fraction of them containing significantly larger contents of higher hydrocarbons than the mean. As gas-fired turbines will be used for power generation all over the world, they will need to tolerate operation with fuels with a wide variety of compositions, particularly with respect to the concentration of higher hydrocarbons and diluents. Subscale catalytic combustion modules typical of those used in gas turbine power generation with ultra low emissions of pollutants were tested in a subscale test system with natural gas alone and with added known levels of hydrocarbon compounds and diluents. The range of compositions tested contained the range observed in the survey. Test results were used to calculate the effect of composition on catalyst performance. The compositional variability is of little consequence to the catalyst for most of the gases in the survey, including nearly all of the gases delivered in the U.S. To accommodate the remaining gases, the catalyst inlet temperature must be lowered to maintain combustor durability. These results support commercial acceptance of catalytic combustion systems for use in natural gas fired turbines in distributed power generation with ultra low NO{sub x} emissions.

Ginter, David; Simchick, Chuck; Schlatter, Jim

2002-03-01

59

Fuel for internal combustion engines  

SciTech Connect

A fuel for internal combustion engines is composed of a mixture of alcohol and gasoline in which the alcohol content is 70 to 85 volume % and the gasoline consists essentially of aromatic, alkanic and cycloalkanic hydrocarbons and, optionally, olefinic hydrocarbons the hydrocarbons having 3-11 carbon atoms, the aromatic hydrocarbons constituting 35 to 45 weight % of the gasoline and the aromatic and any olefinic hydrocarbons constituting cumulatively 35 to 60 weight % of the gasoline.

Ema, S.; Ogasawara, N.; Tsuzuki, K.

1981-07-21

60

Air\\/fuel ratio sensor for an internal combustion engine  

Microsoft Academic Search

A sensor is described for detecting the air\\/fuel ratio of the exhaust gas from an internal combustion engine comprising: a housing, said housing defining a closed air chamber, said air chamber being fluidly sealed from the exhaust gas, an oxygen diffusion cell constructed of an electrolytic material, said diffusion cell having one side exposed to the exhaust gas and a

Hunt

1993-01-01

61

Flameless Combustion for Gas Turbines  

NASA Astrophysics Data System (ADS)

An experimental study of a novel flameless combustor for gas turbine engines is presented. Flameless combustion is characterized by distributed flame and even temperature distribution for high preheat air temperature and large amount of recirculating low oxygen exhaust gases. Extremely low emissions of NOx, CO, and UHC are reported. Measurements of the flame chemiluminescence, CO and NOx emissions, acoustic pressure, temperature and velocity fields as a function of the preheat temperature, inlet air mass flow rate, exhaust nozzle contraction ratio, and combustor chamber diameter are described. The data indicate that larger pressure drop promotes flameless combustion and low NOx emissions at the same flame temperature. High preheated temperature and flow rates also help in forming stable combustion and therefore are favorable for flameless combustion.

Gutmark, Ephraim; Li, Guoqiang; Overman, Nick; Cornwell, Michael; Stankovic, Dragan; Fuchs, Laszlo; Milosavljevic, Vladimir

2006-11-01

62

Evaluation of catalytic combustion of actual coal-derived gas  

NASA Technical Reports Server (NTRS)

The combustion characteristics of a Pt-Pl catalytic reactor burning coal-derived, low-Btu gas were investigated. A large matrix of test conditions was explored involving variations in fuel/air inlet temperature and velocity, reactor pressure, and combustor exit temperature. Other data recorded included fuel gas composition, reactor temperatures, and exhaust emissions. Operating experience with the reactor was satisfactory. Combustion efficiencies were quite high (over 95 percent) over most of the operating range. Emissions of NOx were quite high (up to 500 ppm V and greater), owing to the high ammonia content of the fuel gas.

Blanton, J. C.; Shisler, R. A.

1982-01-01

63

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

DOEpatents

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

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

2014-12-02

64

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

65

Investigation of combustion characteristics of methane-hydrogen fuels  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

66

Exhaust gas purifying system for internal combustion engines  

Microsoft Academic Search

An exhaust gas purifying system of the type utilizing a threeway catalyst containing an oxygen storage material includes an electronic control unit for controlling the amount of secondary air supplied to the exhaust system of an internal combustion engine. The electronic control unit receives a signal from an exhaust air-fuel ratio sensor indicative of an air-fuel ratio of the exhaust

T. Hattori; K. Kondo; J. Naito; T. Nakase

1980-01-01

67

Fundamentals of Gas Turbine combustion  

NASA Technical Reports Server (NTRS)

Combustion problems and research recommendations are discussed in the areas of atomization and vaporization, combustion chemistry, combustion dynamics, and combustion modelling. The recommendations considered of highest priority in these areas are presented.

Gerstein, M.

1979-01-01

68

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. This report summarizes studies conducted under Task 4. The objective was to quantify CWF atomization and combustion properties utilizing industrial/utility scale equipment. Burners were evaluated and combustion performance differences identified for various CWF formulations. 12 refs., 23 figs., 6 tabs.

Lachowicz, Y.V.; LaFlesh, R.C.

1987-07-01

69

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

70

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

71

30 CFR 56.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

72

30 CFR 57.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

73

30 CFR 56.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

74

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

75

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

76

30 CFR 56.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 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...

2010-07-01

77

30 CFR 57.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

78

30 CFR 57.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2011 CFR

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

2011-07-01

79

30 CFR 56.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

80

30 CFR 77.1105 - Internal combustion engines; fueling.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 2011-07-01 false Internal combustion engines; fueling. 77.1105 Section... Fire Protection 77.1105 Internal combustion engines; fueling. Internal combustion engines, except diesels, shall be shut...

2011-07-01

81

30 CFR 77.1105 - Internal combustion engines; fueling.  

Code of Federal Regulations, 2010 CFR

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

2010-07-01

82

30 CFR 57.4103 - Fueling internal combustion engines.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

83

30 CFR 77.1105 - Internal combustion engines; fueling.  

Code of Federal Regulations, 2012 CFR

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

2012-07-01

84

30 CFR 77.1105 - Internal combustion engines; fueling.  

Code of Federal Regulations, 2013 CFR

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

2013-07-01

85

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

86

Fluidized bed combustion of alternative solid fuels  

Microsoft Academic Search

The fluidized bed combustion of a number of alternative fuels of practical interest has been analyzed by a combination of experimental and modeling techniques. Solid fuels of widely different origin (biomass, agricultural, civil and industrial wastes) have been considered in this work. A lab-scale experimental campaign was carried out to evaluate the comminution (fragmentation, attrition) behavior of the fuels. Experimental

Fabrizio Scala; Riccardo Chirone

2004-01-01

87

Combustion Systems for Biomass Fuel  

Microsoft Academic Search

Biomass is one of humanity's earliest sources of energy. Traditionally, biomass has been utilized through direct combustion, and this process is still widely used in many parts of the world. Biomass thermo-chemical conversion investigations are certainly not the most important options at present; combustion is responsible for over 97% of the world's bio-energy production. Biomass combustion is a series of

Ayhan Demirbas

2007-01-01

88

Enhanced Efficiency of Internal Combustion Engines By Employing Spinning Gas  

SciTech Connect

The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A gain in fuel efficiency of several percent is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in the efficiency.

Geyko, Vasily; Fisch, Nathaniel

2014-02-27

89

Enhanced efficiency of internal combustion engines by employing spinning gas  

NASA Astrophysics Data System (ADS)

The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A remarkable gain in fuel efficiency is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in efficiency.

Geyko, V. I.; Fisch, N. J.

2014-08-01

90

Enhanced efficiency of internal combustion engines by employing spinning gas.  

PubMed

The efficiency of the internal combustion engine might be enhanced by employing spinning gas. A gas spinning at near sonic velocities has an effectively higher heat capacity, which allows practical fuel cycles, which are far from the Carnot efficiency, to approach more closely the Carnot efficiency. A remarkable gain in fuel efficiency is shown to be theoretically possible for the Otto and Diesel cycles. The use of a flywheel, in principle, could produce even greater increases in efficiency. PMID:25215720

Geyko, V I; Fisch, N J

2014-08-01

91

Superheated fuel injection for combustion of liquid-solid slurries  

SciTech Connect

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 reducted 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, F. A.

1985-12-17

92

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

93

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

94

Catalytic combustion of heavy partially-vaporized fuels  

NASA Technical Reports Server (NTRS)

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

Rosfjord, T. J.

1980-01-01

95

Combustion of biomass and low CV fuels  

Microsoft Academic Search

This paper reviews the progress made in several areas concerning the combustion of biomass and low calorific value fuels at Cardiff over the last 20 years, including: Efficient utilisation of low calorific value gases. The use of cyclone combustors with poor quality solid fuels. Pyrolysis processes and wastes. Small efficient, well controlled, batch fed biomass stoves.Conclusions are drawn as to

T. ODoherty

2000-01-01

96

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

97

Low-Btu coal-gasification-process design report for Combustion Engineering/Gulf States Utilities coal-gasification demonstration plant. [Natural gas or No. 2 fuel oil to natural gas or No. 2 fuel oil or low Btu gas  

SciTech Connect

This report describes a coal gasification demonstration plant that was designed to retrofit an existing steam boiler. The design uses Combustion Engineering's air blown, atmospheric pressure, entrained flow coal gasification process to produce low-Btu gas and steam for Gulf States Utilities Nelson No. 3 boiler which is rated at a nominal 150 MW of electrical power. Following the retrofit, the boiler, originally designed to fire natural gas or No. 2 oil, will be able to achieve full load power output on natural gas, No. 2 oil, or low-Btu gas. The gasifier and the boiler are integrated, in that the steam generated in the gasifier is combined with steam from the boiler to produce full load. The original contract called for a complete process and mechanical design of the gasification plant. However, the contract was curtailed after the process design was completed, but before the mechanical design was started. Based on the well defined process, but limited mechanical design, a preliminary cost estimate for the installation was completed.

Andrus, H E; Rebula, E; Thibeault, P R; Koucky, R W

1982-06-01

98

Preliminary test on combustion of wood derived fast pyrolysis oils in a gas turbine combustor  

Microsoft Academic Search

Industrial gas turbines fueled by fast pyrolysis liquid made from biomass are a promising option for electricity generation from a renewable resource. This paper reports a preliminary study on combustion of wood derived fast pyrolysis oils and their mixtures with ethanol in a gas turbine combustor. The combustion of these biofuels is analyzed and their possible use in a gas

G. Lpez Juste; J. J. Salv Monfort

2000-01-01

99

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

Microsoft Academic Search

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

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

1993-01-01

100

Fluidized bed combustion of alternative solid fuels; status, successes and problems of the technology  

Microsoft Academic Search

Fluidized bed combustion can be used for energy production or incineration for almost any material containing carbon, hydrogen and sulphur in a combustible form, whether it be in the form of a solid, liquid, slurry or gas. The technology's fuel flexibility arises from the fact that the fuel is present in the combustor at a low level and is burnt

E. J Anthony

1995-01-01

101

Fuel-rich catalytic combustion of a high density fuel  

NASA Technical Reports Server (NTRS)

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

Brabbs, Theodore A.; Merritt, Sylvia A.

1993-01-01

102

Fuel gas from biodigestion  

NASA Technical Reports Server (NTRS)

Biodigestion apparatus produces fuel gas (primarily methane) for domestic consumption, by anaerobic bacterial digestion of organic matter such as aquatic vegetation. System includes 3,786-1 cylindrical container, mechanical agitator, and simple safe gas collector for short term storage.

Mcdonald, R. C.; Wolverton, B. C.

1979-01-01

103

Combustion Temperature Measurement by Spontaneous Raman Scattering in a Jet-A Fueled Gas Turbine Combustor Sector  

NASA Technical Reports Server (NTRS)

Spontaneous vibrational Raman scattering was used to measure temperature in an aviation combustor sector burning jet fuel. The inlet temperature ranged from 670 K (750 F) to 756 K (900 F) and pressures from 13 to 55 bar. With the exception of a discrepancy that we attribute to soot, good agreement was seen between the Raman-derived temperatures and the theoretical temperatures calculated from the inlet conditions. The technique used to obtain the temperature uses the relationship between the N2 anti-Stokes and Stokes signals, within a given Raman spectrum. The test was performed using a NASA-concept fuel injector and Jet-A fuel over a range of fuel/air ratios. This work represents the first such measurements in a high-pressure, research aero-combustor facility.

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

2002-01-01

104

Techno-economic analysis of sour gas oxy-fuel combustion power cycles for carbon capture and sequestration  

E-print Network

The world's growing energy demand coupled with the problem of global warming have led us to investigate new energy sources that can be utilized in a way to reduce carbon dioxide emissions than traditional fossil fuel power ...

Chakroun, Nadim Walid

2014-01-01

105

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

106

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

107

Fuel-cycle greenhouse gas emissions from alternative fuels in Australian heavy vehicles  

Microsoft Academic Search

This paper quantifies the expected pre-combustion and combustion emissions of greenhouse gases from Australian heavy vehicles using alternative fuels. We use the term exbodied emissions for these full fuel-cycle emissions. The fuels examined are low sulfur diesel (LSD), ultra-low sulfur diesel (ULS), compressed natural gas (CNG), liquefied natural gas (LNG), liquefied petroleum gas (LPG), ethanol (from lignocellulose), biodiesel and waste

Tom Beer; Tim Grant; David Williams; Harry Watson

2002-01-01

108

ON-LINE MEASUREMENT OF NITROUS OXIDE FROM COMBUSTION SOURCES BY AUTOMATED GAS CHROMATOGRAPHY  

EPA Science Inventory

The paper discusses on-line measurement of nitrous oxide (N2O) from combustion sources by automated gas chromatography. ossil fuel combustion is suspected of contributing to measured increases in the ambient concentrations of N2O. haracterization of N2O emissions from fossil fuel...

109

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

110

Combustion liner for a gas turbine engine  

Microsoft Academic Search

This patent describes, for a gas turbine power plant, a combustor having panels generally circular in shape and extending axially arranged end to end to define an annular combustion chamber. Each of the panels have an inner surface subjected to combustion gases and an outer surface subjected to power plant cooler air. It also has means on the downstream end

1986-01-01

111

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

112

Fuel and Combustion Characteristics of Organic Wastes  

NASA Astrophysics Data System (ADS)

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

Namba, Kunihiko; Ida, Tamio

113

FUEL NOX CONTROL BY CATALYTIC COMBUSTION  

EPA Science Inventory

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

114

CONTROLLING EMISSIONS FROM FUEL AND WASTE COMBUSTION  

EPA Science Inventory

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

115

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

SciTech Connect

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

Not Available

2014-12-01

116

A review on the technical adaptations for internal combustion engines to operate with gas\\/hydrogen mixtures  

Microsoft Academic Search

The use of the hydrogen as fuel in the internal combustion engine represents an alternative use to replace the hydrocarbons fuels, which produce during the combustion reaction a pollutes gases. The hydrogen is the most abundant material in the universe and during its combustion with air only produces nitrous oxides (NOx) gas, which can collect and avoid their emission to

M. A. Escalante Soberanis; A. M. Fernandez

2010-01-01

117

Heavy duty gas turbine combustion tests with simulated low BTU coal gas  

NASA Astrophysics Data System (ADS)

This program has the objectives to: parametrically determine the effects of moisture, nitrogen and carbon dioxide as diluents so that the combustion characteristics of many varieties of gasification product gases can be reasonably predicted without physically testing each specific gas composition; determine emissions characteristics including NO, NO(x), CO, levels etc. associated with each of the diluents; and operate with at least two syngas compositions -- DOE chosen air-blown and integrate oxygen-blown, to confirm that the combustion characteristics are in line with predictions. As a result of this program: GE Engineering is now confident that the syngas fuels produced by all currently viable coal gasifiers can be accommodated by the GE advanced ('F' Technology) combustion system; and for proposed syngas fuels with varying amounts of steam, nitrogen or CO2 diluent, the combustion and emissions characteristics can be reasonably estimated without undertaking expensive new screening tests for each different fuel.

Ekstrom, T. E.; Battista, R. A.; Belisle, F. H.; Maxwell, G. P.

118

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

E-print Network

/biofuel burning and fossil fuel combustion 3 S. A. Guazzotti,1 D. T. Suess,1,2 K. R. Coffee,1,3 P. K. Quinn,4 T. S, or proximate sources. Aerosol and trace gas 21 measurements provide evidence that emissions from fossil fuel Peninsula, where dominance of fossil fuel combustion is suggested by 30 results from single

Dickerson, Russell R.

119

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

120

Fireside Corrosion in Oxy-fuel Combustion of Coal  

SciTech Connect

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

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

2012-05-20

121

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

122

Development of a catalytic combustion system for the MIT Micro Gas Turbine Engine  

E-print Network

As part of the MIT micro-gas turbine engine project, the development of a hydrocarbon-fueled catalytic micro-combustion system is presented. A conventionally-machined catalytic flow reactor was built to simulate the ...

Peck, Jhongwoo, 1976-

2003-01-01

123

A Dual-Line Detection Rayleigh Scattering Diagnostic Technique for the Combustion of Hydrocarbon Fuels and Filtered UV Rayleigh Scattering for Gas Velocity Measurements  

NASA Technical Reports Server (NTRS)

Non-intrusive techniques for the dynamic measurement of gas flow properties such as density, temperature and velocity, are needed in the research leading to the development of new generation high-speed aircraft. Accurate velocity, temperature and density data obtained in ground testing and in-flight measurements can help understand the flow physics leading to transition and turbulence in supersonic, high-altitude flight. Such non-intrusive measurement techniques can also be used to study combustion processes of hydrocarbon fuels in aircraft engines. Reliable, time and space resolved temperature measurements in various combustor configurations can lead to a better understanding of high temperature chemical reaction dynamics thus leading to improved modeling and better prediction of such flows. In view of this, a research program was initiated at Polytechnic University's Aerodynamics Laboratory with support from NASA Lewis Research Center through grants NAG3-1301 and NAG3-1690. The overall objective of this program has been to develop laser-based, non-contact, space- and time-resolved temperature and velocity measurement techniques. In the initial phase of the program a ND:YAG laser-based dual-line Rayleigh scattering technique was developed and tested for the accurate measurement of gas temperature in the presence of background laser glare. Effort was next directed towards the development of a filtered, spectrally-resolved Rayleigh/Mie scattering technique with the objective of developing an interferometric method for time-frozen velocity measurements in high-speed flows utilizing the uv line of an ND:YAG laser and an appropriate molecular absorption filter. This effort included both a search for an appropriate filter material for the 266 nm laser line and the development and testing of several image processing techniques for the fast processing of Fabry-Perot images for velocity and temperature information. Finally, work was also carried out for the development of a new laser-based strain-rate and vorticity technique for the time-resolved measurement of vorticity and strain-rates in turbulent flows.

Otugen, M. Volkan

1997-01-01

124

The acoustic model of oscillations of gas combustion in coaxial pipes  

NASA Astrophysics Data System (ADS)

Organization of pulse combustion mode is one of the possible solutions to the problem of energy efficiency installations using hydrocarbon fuel. For grate combustion of solid fuels, in particular, solid industrial wastes are considered to be promising coaxial system, allowing the admission of secondary air to the combustion zone. In this paper we proposed an acoustic model of oscillations of gas when burning solid fuel in the system is coaxially arranged pipes with natural air supply. The description of the motion of the gas in the system during one period of oscillation.

Semenova, E. V.; Larionov, V. M.; Kazakova, E. I.

2014-11-01

125

Biomass fuel combustion and health*  

PubMed Central

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

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

1985-01-01

126

Combustion of liquid-fuel droplets in supercritical conditions  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

127

In-water gas combustion in linear and annular gas bubbles  

NASA Astrophysics Data System (ADS)

A new pulsed-cyclic method of in-water gas combustion was developed with separate feed of fuel gas and oxygen with the focus on development of new technologies for heat generators and submerged propellers. The results of calorimetric and hydrodynamic measurements are presented. In-water combustion of acetylene, hydrogen, and propane was tested with the operation frequency of 2-2.5 Hz and with a linear injector. The combustion dynamics of combustion of stoichiometric mixture with propane (C3H8+5O2) was studied for a bubble near a solid wall; the produced gas bubble continues expansion and oscillations (for the case of linear and annular bubbles). It was demonstrated that gas combustion in annular bubbles produces two same-magnitude pulses of force acting on the wall. The first pulse is produced due to expansion of combustion products, and the second pulse is produced due to axial cumulative processes after bubble collapse. This process shapes an annular vortex which facilitates high-speed convective processes between combustion products and liquid; and this convection produces small-size bubbles.

Teslenko, V. S.; Drozhzhin, A. P.; Medvedev, R. N.; Batraev, I. S.

2014-08-01

128

Vaporization and combustion of fuel droplets at supercritical conditions  

NASA Technical Reports Server (NTRS)

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

Yang, Vigor

1991-01-01

129

Gasification Evaluation of Gas Turbine Combustion  

SciTech Connect

This report provides a preliminary assessment of the potential for use in gas turbines and reciprocating gas engines of gases derived from biomass by pyrolysis or partial oxidation with air. Consideration was given to the use of mixtures of these gases with natural gas as a means of improving heating value and ensuring a steady gas supply. Gas from biomass, and mixtures with natural gas, were compared with natural gas reformates from low temperature partial oxidation or steam reforming. The properties of such reformates were based on computations of gas properties using the ChemCAD computational tools and energy inputs derived from known engine parameters. In general, the biomass derived fuels compare well with reformates, so far as can be judged without engine testing. Mild reforming has potential to produce a more uniform quality of fuel gas from very variable qualities of natural gas, and could possibly be applied to gas from biomass to eliminate organic gases and condensibles other than methane.

Battelle

2003-12-30

130

Co-combustion of refuse derived fuel and coal in a cyclone furnace at the Baltimore Gas and Electric Company, C. P. Crane Station  

SciTech Connect

A co-combustion demonstration burn of coal and fluff refuse-derived fuel (RDF) was conducted by Teledyne National and Baltimore Gas and Electric Company. This utility has two B and W cyclone furnaces capable of generating 400 MW. The facility is under a prohibition order to convert from No. 6 oil to coal; as a result, it was desirable to demonstrate that RDF, which has a low sulfur content, can be burned in combination with coals containing up to 2% sulfur, thus reducing overall sulfur emissions without deleterious effects. Each furnace consists of four cyclones capable of generating 1,360,000 pounds per hour steam. The tertiary air inlet of one of the cyclones was modified with an adapter to permit fluff RDF to be pneumatically blown into the cyclone. At the same time, coal was fed into the cyclone furnace through the normal coal feeding duct, where it entered the burning chamber tangentially and mixed with the RDF during the burning process. Secondary shredded fluff RDF was prepared by the Baltimore County Resource Recovery Facility. The RDF was discharged into a receiving station consisting of a belt conveyor discharging into a lump breaker, which in turn, fed the RDF into a pneumatic line through an air-lock feeder. A total of 2316 tons were burned at an average rate of 5.6 tons per hour. The average heat replacement by RDF for the cyclone was 25%, based on Btu input for a period of forty days. The range of RDF burned was from 3 to 10 tons per hour, or 7 to 63% heat replacement. The average analysis of the RDF (39 samples) for moisture, ash, heat (HHV) and sulfur content were 18.9%, 13.4%, 6296 Btu/lb and 0.26% respectively. RDF used in the test was secondary shredded through 1-1/2 inch grates producing the particle size distribution of from 2 inches to .187 inches. Findings to date after inspection of the boiler and superheater indicate satisfactory results with no deleterious effects from the RDF.

Not Available

1982-03-01

131

Cover and startup gas supply system for solid oxide fuel cell generator  

DOEpatents

A cover and startup gas supply system for a solid oxide fuel cell power generator is disclosed. Hydrocarbon fuel, such as natural gas or diesel fuel, and oxygen-containing gas are supplied to a burner. Combustion gas exiting the burner is cooled prior to delivery to the solid oxide fuel cell. The system mixes the combusted hydrocarbon fuel constituents with hydrogen which is preferably stored in solid form to obtain a non-explosive gas mixture. The system may be used to provide both non-explosive cover gas and hydrogen-rich startup gas to the fuel cell. 4 figs.

Singh, P.; George, R.A.

1999-07-27

132

A study of the combustion and emission characteristics of compressed-natural-gas direct-injection stratified combustion using a rapid-compression-machine  

Microsoft Academic Search

The objective of the present study is to determine the characteristics of combustion and emissions of compressed-natural-gas (CNG) direct-injection combustion using a rapid-compression-machine which has a compression ratio of 10 and a disc-shaped combustion chamber. Combustion and emission characteristics are compared for three types of fuel injection (single side, parallel side and opposed side injection) and a homogeneous mixture. The

S. Shiga; S. Ozone; H. T. C. Machacon; T. Karasawa; H. Nakamura; T. Ueda; N. Jingu; Z. Huang; M. Tsue; M. Kono

2002-01-01

133

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

134

Chemistry and radiation in oxy-fuel combustion: A computational fluid dynamics modeling study  

Microsoft Academic Search

In order to investigate the role of combustion chemistry and radiation heat transfer in oxy-fuel combustion modeling, a computational fluid dynamics (CFD) modeling study has been performed for two different oxy-fuel furnaces. One is a lab-scale 0.8MW oxy-natural gas flame furnace whose detailed in-flame measurement data are available; the other is a conventional 609MW utility boiler which is assumed to

Chungen Yin; Lasse A. Rosendahl; Sren K. Kr

2011-01-01

135

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

136

Recent advances in the combustion of water fuel emulsion  

Microsoft Academic Search

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

T. Kadota; H. Yamasaki

2002-01-01

137

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

SciTech Connect

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

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

1998-05-01

138

Advanced bioreactor concepts for gaseous substrates: Conversion of synthesis gas to liquid fuels and removal of SO{sub x} and NO{sub x} from coal combustion gases. CRADA final report  

SciTech Connect

The purpose of the proposed research program was the development and demonstration of a new generation of gaseous substrate-based bioreactors for the production of liquid fuels from coal synthesis gas and the removal of NO{sub x} and SO{sub x} species from coal combustion flue gas. This study addressed the further investigation of optimal bacterial strains, growth media and kinetics for the biocatalytic conversion of coal synthesis gas to liquid fuel such as ethanol and the reduction of gaseous flue gas constituents. The primary emphasis was on the development of advanced bioreactor systems coupled with innovative biocatalytic systems that will provide increased productivity under controlled conditions. It was hoped that this would result in bioprocessing options that have both technical and economic feasibility, thus, ensuring early industrial use. Predictive mathematical models were formulated to accommodate hydrodynamics, mass transport, and conversion kinetics, and provide the data base for design and scale-up. The program was separated into four tasks: (1) Optimization of Biocatalytic Kinetics; (2) Development of Well-mixed and Columnar Reactors; (3) Development of Predictive Mathematical Models; and (4) Industrial Demonstration. Research activities addressing both synthesis gas conversion and flue gas removal were conducted in parallel by BRI and ORNL respectively.

Kaufman, E.N.; Selvaraj, P.T.

1997-10-01

139

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

SciTech Connect

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

Kato, S.; Onishi, S.

1987-01-01

140

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

141

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

NASA Technical Reports Server (NTRS)

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

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

2004-01-01

142

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

143

Fuel gas desulfurization  

DOEpatents

A method for removing sulfurous gases such as H.sub.2 S and COS from a fuel gas is disclosed wherein limestone particulates containing iron sulfide provide catalytic absorption of the H.sub.2 S and COS by the limestone. The method is effective at temperatures of 400.degree. C. to 700.degree. C. in particular.

Yang, Ralph T. (Tonawanda, NY); Shen, Ming-Shing (Rocky Point, NY)

1981-01-01

144

Synthetic fuel aromaticity and staged combustion  

SciTech Connect

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

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

1982-11-15

145

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

146

Combustion and emissions characteristics of a compression-ignition engine using dual ammonia-diesel fuel  

Microsoft Academic Search

This study investigated the performance of a compression-ignition engine using a dual-fuel approach with ammonia and diesel fuel. With the world's increasing need for alternative energy and clean emissions, ammonia stands out as a viable candidate since its combustion does not produce the known greenhouse gas, carbon dioxide. Ammonia is one of the world's most synthesized chemicals and its infrastructure

Aaron Reiter

2009-01-01

147

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

DOEpatents

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

Heffel, James W. (Lake Matthews, CA); Scott, Paul B. (Northridge, CA); Park, Chan Seung (Yorba Linda, CA)

2011-11-01

148

Vaporized fuel control apparatus for internal combustion engines  

Microsoft Academic Search

A vaporized fuel control apparatus is described for an internal combustion engine, the apparatus comprising: a refuelling canister for adsorbing fuel vapor formed in the fuel tank during a refuelling thereof; a running canister for adsorbing fuel vapor formed in the fuel tank during a running of the engine; a first electromagnetic valve provided in a path for discharging the

T. Abe; M. Kiyono; M. Takao

1989-01-01

149

Carbonaceous fuel combustion with improved desulfurization  

DOEpatents

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

Yang, Ralph T. (Middle Island, NY); Shen, Ming-shing (Rocky Point, NY)

1980-01-01

150

THERMAL LOADING AND TEMPEARTURE DISTRIBUTION OF A PRE COMBUSTION CHAMBER DIESEL ENGINE RUNNING ON GASOIL \\/ NATURAL GAS  

Microsoft Academic Search

Heat flux and temperature distribution were carried out in the combustion chamber of a pre-combustion chamber diesel engine running on dual fuel of diesel and natural gas. The test rig consists of a pre- combustion chamber single cylinder diesel engine fully equipped for temperature measurements across different points in the cylinder head, cylinder liner and other critical areas of the

Mohamed Y. E. Selim

151

Axially staged combustion system for a gas turbine engine  

DOEpatents

An axially staged combustion system is provided for a gas turbine engine comprising a main body structure having a plurality of first and second injectors. First structure provides fuel to at least one of the first injectors. The fuel provided to the one first injector is adapted to mix with air and ignite to produce a flame such that the flame associated with the one first injector defines a flame front having an average length when measured from a reference surface of the main body structure. Each of the second injectors comprising a section extending from the reference surface of the main body structure through the flame front and having a length greater than the average length of the flame front. Second structure provides fuel to at least one of the second injectors. The fuel passes through the one second injector and exits the one second injector at a location axially spaced from the flame front.

Bland, Robert J. (Oviedo, FL)

2009-12-15

152

Combustion of liquid fuel droplets in supercritical conditions  

NASA Technical Reports Server (NTRS)

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

Shuen, J. S.; Yang, Vigor

1991-01-01

153

Combustion process with waste gas purification  

SciTech Connect

The invention relates to a combustion process with cleansing of the waste gases by compressing, cooling and expanding said gases. The invention provides a continuous process in which highly contaminated low-grade fuels having a high water content can be effectively burned and the waste gases efficiently cleansed, by subjecting the cooled waste gases, together with residual non-desired substances, to a rapid drop in pressure in one or more stages by means of an expansion means, whereat the input drive power of the compressor, required for compressing said gases, is so high that the temperature downstream of the expansion means is sufficiently low for the condensation and precipitation of frozen contaminants in the waste gases, together with ice crystals. The invention can be applied to all forms of combustion plants, primarily combined power and heating plants fired with fuel having a high sulphur and water content.

Almlof, G.; Hagqvist, P.

1983-07-12

154

Methodology development of a time-resolved in-cylinder fuel oxidation analysis: Homogeneous charge compression ignition combustion study application  

SciTech Connect

A technique was developed and applied to understand the mechanism of fuel oxidation in an internal combustion engine. This methodology determines the fuel and concentrations of various intermediates during the combustion cycle. A time-resolved measurement of a large number of species is the objective of this work and is achieved by the use of a sampling probe developed in-house. A system featuring an electromagnetically actuated sampling valve with internal N{sub 2} dilution was developed for sampling gases coming from the combustion chamber. Combustion species include O{sub 2}, CO{sub 2}, CO, NO{sub x}, fuel components, and hydrocarbons produced due to incomplete combustion of fuel. Combustion gases were collected and analyzed with the objectives of analysis by an automotive exhaust analyzer, separation by gas chromatography, and detection by flame ionization detection and mass spectrometry. The work presented was processed in a homogeneous charge compression ignition combustion mode context. (author)

Nowak, L.; Guibert, P.; Cavadias, S. [Universite de Pierre et Marie Curie, Institut Jean Le Rond D'Alembert CNRS UMR 7190, 2 place de la Gare de Ceinture, 78210 Saint Cyr l'Ecole (France); Dupre, S.; Momique, J.C. [PSA Peugeot Citroen, Centre Technique de Velizy, Route de Gizy, 78943 Velizy-Villacoublay (France)

2008-08-15

155

COMBUSTION SOURCES OF UNREGULATED GAS PHASE NITROGENEOUS SPECIES  

E-print Network

use the of lean bacterial Estimates of production of N othat N0 2 production peaked at the lean air/fuel ratio oflean combustion systems. laboratory combustion systems have also revealed the production

Matthews, Ronald D.

2013-01-01

156

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

157

Catalytic combustion of low heating value gas mixtures: comparison between laboratory and pilot scale tests  

Microsoft Academic Search

Catalytic combustion of low heating value fuels is a promising method for electricity production combining the use of a renewable fuel with ultra-low emissions. In the present work, catalytic combustion of a low heating value gas has been studied over monolithic catalysts in an atmospheric 30kW pilot catalytic combustor connected to a wood pellet gasifier. The results have been compared

Magnus Berg; E Magnus Johansson; Sven G Jrs

2000-01-01

158

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

SciTech Connect

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

Bazyn, Timothy; Gehrke, Christopher

2014-10-28

159

Advanced coal-fueled gas turbine systems  

SciTech Connect

Several technology advances since the early coal-fueled turbine programs that address technical issues of coal as a turbine fuel have been developed in the early 1980s: Coal-water suspensions as fuel form, improved methods for removing ash and contaminants from coal, staged combustion for reducing NO{sub x} emissions from fuel-bound nitrogen, and greater understanding of deposition/erosion/corrosion and their control. Several Advanced Coal-Fueled Gas Turbine Systems programs were awarded to gas turbine manufacturers for for components development and proof of concept tests; one of these was Allison. Tests were conducted in a subscale coal combustion facility and a full-scale facility operating a coal combustor sized to the Allison Model 501-K industrial turbine. A rich-quench-lean (RQL), low nitrogen oxide combustor design incorporating hot gas cleanup was developed for coal fuels; this should also be applicable to biomass, etc. The combustor tests showed NO{sub x} and CO emissions {le} levels for turbines operating with natural gas. Water washing of vanes from the turbine removed the deposits. Systems and economic evaluations identified two possible applications for RQL turbines: Cogeneration plants based on Allison 501-K turbine (output 3.7 MW(e), 23,000 lbs/hr steam) and combined cycle power plants based on 50 MW or larger gas turbines. Coal-fueled cogeneration plant configurations were defined and evaluated for site specific factors. A coal-fueled turbine combined cycle plant design was identified which is simple, compact, and results in lower capital cost, with comparable efficiency and low emissions relative to other coal technologies (gasification, advanced PFBC).

Wenglarz, R.A.

1994-08-01

160

Gas leakage measurements in a cold model of an interconnected fluidized bed for chemical-looping combustion  

Microsoft Academic Search

In chemical-looping combustion (CLC) a gaseous fuel is burnt with inherent separation of the greenhouse gas carbon dioxide. The oxygen is transported from the combustion air to the fuel by means of metal oxide particles acting as oxygen carriers. A CLC system can be designed similar to a circulating fluidized bed, but with the addition of a bubbling fluidized bed

E Johansson; A Lyngfelt; T Mattisson; F Johnsson

2003-01-01

161

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

162

Chemically enhanced combustion of water-slurry fuels  

Microsoft Academic Search

A method of enhancing the combustion of solid fuel\\/-water slurries by the addition of about 100 to 5,000 ppm of a stable water-soluble explosive, which will detonate early in the combustion process, thereby producing a secondary dispersion of fuel particles, and an 80-65% coal\\/20-35% water composition suitable for secondary dispersion during combustion containing about 100-5,000 ppm of a water-soluble explosive,

Olen

1984-01-01

163

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

164

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

165

Trace gas emissions from combustion of peat, crop residue, biofuels, grasses, and other fuels: configuration and FTIR component of the fourth Fire Lab at Missoula Experiment (FLAME-4)  

NASA Astrophysics Data System (ADS)

During the fourth Fire Lab at Missoula Experiment (FLAME-4, October-November~2012) a~large variety of regionally and globally significant biomass fuels was burned at the US Forest Service Fire Sciences Laboratory in Missoula, Montana. The particle emissions were characterized by an extensive suite of instrumentation that measured aerosol chemistry, size distribution, optical properties, and cloud-nucleating properties. The trace gas measurements included high resolution mass spectrometry, one- and two-dimensional gas chromatography, and open-path Fourier transform infrared (OP-FTIR) spectroscopy. This paper summarizes the overall experimental design for FLAME-4 including the fuel properties, the nature of the burn simulations, the instrumentation employed, and then focuses on the OP-FTIR results. The OP-FTIR was used to measure the initial emissions of 20 trace gases: CO2, CO, CH4, C2H2, C2H4, C3H6, HCHO, HCOOH, CH3OH, CH3COOH, glycolaldehyde, furan, H2O, NO, NO2, HONO, NH3, HCN, HCl, and SO2. These species include most of the major trace gases emitted by biomass burning and for several of these compounds it is the first time their emissions are reported for important fuel types. The main fuel types included: African grasses, Asian rice straw, cooking fires (open (3-stone), rocket, and gasifier stoves), Indonesian and extratropical peat, temperate and boreal coniferous canopy fuels, US crop residue, shredded tires, and trash. Comparisons of the OP-FTIR emission factors (EF) and emission ratios (ER) to field measurements of biomass burning verify that the large body of FLAME-4 results can be used to enhance the understanding of global biomass burning and its representation in atmospheric chemistry models.

Stockwell, C. E.; Yokelson, R. J.; Kreidenweis, S. M.; Robinson, A. L.; DeMott, P. J.; Sullivan, R. C.; Reardon, J.; Ryan, K. C.; Griffith, D. W. T.; Stevens, L.

2014-04-01

166

Mercury transformations in coal combustion flue gas  

Microsoft Academic Search

Mercury chlorination [i.e., formation of HgCl2(g)] is generally assumed to be the dominant mercury-transformation mechanism in coal combustion flue gas. Other potential mechanisms involve mercury interactions with ash particle surfaces where reactive chemical species, oxidation catalysts, and active sorption sites are available to transform Hg0(g) to Hg2+X(g) (e.g., where X is Cl2 or O) as well as Hg0(g) and HgCl2(g)

Kevin C. Galbreath; Christopher J. Zygarlicke

2000-01-01

167

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. Discussions on transport, rheology, combustion properties, and ash characterization are included. 11 refs., 9 figs., 7 tabs.

Chow, O.K.; Patel, R.L.; Levasseur, A.A.

1987-07-01

168

National Combustion Code Used To Study the Hydrogen Injector Design for Gas Turbines  

NASA Technical Reports Server (NTRS)

Hydrogen, in the gas state, has been proposed to replace Jet-A (the fuel used for commercial jet engines) as a fuel for gas turbine combustion. For the combustion of hydrogen and oxygen only, water is the only product and the main greenhouse gas, carbon dioxide, is not produced. This is an obvious benefit of using hydrogen as a fuel. The situation is not as simple when air replaces oxygen in the combustion process. (Air is mainly a mixture of oxygen, nitrogen, and argon. Other components comprise a very small part of air and will not be mentioned.) At the high temperatures found in the combustion process, oxygen reacts with nitrogen, and this produces nitrogen oxide compounds, or NOx--the main component of atmospheric smog. The production of NOx depends mainly on two variables: the temperature at which combustion occurs, and the length of time that the products of combustion stay, or reside, in the combustor. Starting from a lean (excess air) air-to-fuel ratio, the goal of this research was to minimize hot zones caused by incomplete premixing and to keep the residence time short while producing a stable flame. The minimization of these two parameters will result in low- NOx hydrogen combustion.

Iannetti, Anthony C.; Norris, Andrew T.; Shih, Tsan-Hsing

2005-01-01

169

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

170

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

NASA Technical Reports Server (NTRS)

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

Schoenman, L.

1981-01-01

171

Performance of low-Btu fuel gas turbine combustors  

SciTech Connect

This reports on a project to develop low BTU gas fuel nozzle for use in large gas turbine combustors using multiple fuel nozzles. A rich-quench-lean combustor is described here which reduces the amount of NO{sub x} produced by the combustion of the low BTU gas. The combustor incorporates a converging rich stage combustor liner, which separates the rich stage recirculation zones from the quench stage and lean stage air.

Bevan, S.; Bowen, J.H.; Feitelberg, A.S.; Hung, S.L.; Lacey, M.A.; Manning, K.S.

1995-11-01

172

LIEKKI and JALO: Combustion and fuel conversion  

NASA Astrophysics Data System (ADS)

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

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

173

Device for admitting exhaust gases and fuel-air mixtures into the cylinders of an internal combustion engine  

Microsoft Academic Search

A device is proposed for the supply of operating air-fuel mixtures including exhaust gases to internal combustion engines. Between the opening periods of the inlet valves of an internal combustion engine, precisely dispensed quantities of recirculated exhaust gas are pre-stored in the intake channel directly upstream of the inlet valve whereby a stratification of exhaust gas and fuel-air mixture in

K. Eckert; H. Britsch; E. Linder; K. Muller; W. Polach

1984-01-01

174

Ceramic-coated components for the combustion zone of natural gas engines  

NASA Astrophysics Data System (ADS)

The use of ceramic coatings on the combustion zone surfaces of large,natural gas-fueled,internal com-bustion engines is discussed. Unique handling and quality control systems are required for plasma spray-ing thin (0.25 mm,0.0010) in.coatings on up to 48.25(cm19)-in.diameter piston crowns and cylinder heads weighing up to(1200 lb).The in-service performance characteristics of two types of natural gas-fu-eled combustion engines powering natural gas compressors that had thin zirconia ceramic coatings ap-plied to their combustion zone surfaces are presented. Their performance was measured in the field be-fore and after coating. It was determined that the durability,power output,fuel consumption,exhaust emissions,and other operating characteristics all improved due to ceramic coating of the flame side sur-faces of cylinder heads,power pistons,and valves.

Holloman, L.; Levy, A. V.

1992-03-01

175

Fuel burner and combustor assembly for a gas turbine engine  

DOEpatents

A fuel burner and combustor assembly for a gas turbine engine has a housing within the casing of the gas turbine engine which housing defines a combustion chamber and at least one fuel burner secured to one end of the housing and extending into the combustion chamber. The other end of the fuel burner is arranged to slidably engage a fuel inlet connector extending radially inwardly from the engine casing so that fuel is supplied, from a source thereof, to the fuel burner. The fuel inlet connector and fuel burner coact to anchor the housing against axial movement relative to the engine casing while allowing relative radial movement between the engine casing and the fuel burner and, at the same time, providing fuel flow to the fuel burner. For dual fuel capability, a fuel injector is provided in said fuel burner with a flexible fuel supply pipe so that the fuel injector and fuel burner form a unitary structure which moves with the fuel burner.

Leto, Anthony (Franklin Lakes, NJ)

1983-01-01

176

[Ecological/hygienic and toxicological evaluation of combustion products of aviation kerosene and liquefied natural gas].  

PubMed

Products of kerosene combustion in the present-day aeroengines contain more than 200 compounds of incomplete combustion, partial oxidation, and thermal decomposition of fuel and oil. Most of these are strong toxicants for humans. Increase of temperature in the turbine engine combustion chamber led to production of very toxic nitrogen oxides. In search for the ecologically safe and less toxic alternative attention of fuel engineers was drawn to liquefied natural gas which compares well and even excels kerosene in ecological, economic and many other respects. PMID:16999075

Afanas'ev, R V; Berezin, G I; Raznoschikov, V V

2006-01-01

177

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

178

Environmental implications of alternative-fueled automobiles: Air quality and greenhouse gas tradeoffs  

Microsoft Academic Search

The authors analyze alternative fuel-powerstrain options for internal combustion engine automobiles. Fuel\\/engine efficiency, energy use, pollutant discharges, and greenhouse gas emissions are estimated for spark and compression ignited, direct injected (DI), and indirect injected (II) engines fueled by conventional and reformulated gasoline, reformulated diesel, compressed natural gas (CNG), and alcohols. Since comparisons of fuels and technologies in dissimilar vehicles are

Heather L. MacLean; Lester B. Lave

2000-01-01

179

The Impact of Alternative Fuels on Combustion Kinetics  

SciTech Connect

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

Pitz, W J; Westbrook, C K

2009-07-30

180

Pilot fuel ignited stratified charge rotary combustion engine and fuel injector therefor  

Microsoft Academic Search

For a pilot fuel ignited stratified charge rotary, internal combustion engine, the fuel injection system and a fuel injector therefor comprises a fuel injector having plural discharge ports with at least one of the discharge ports located to emit a ''pilot'' fuel charge (relatively rich fuel-air mixture) into a passage in the engine housing, which passage communicates with the engine

Loyd

1980-01-01

181

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 gassolid 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

182

A Review of NOx Formation Under Gas-Turbine Combustion Conditions  

Microsoft Academic Search

Gas turbines offer very high cycle efficiency, exceeding 50% in modern 250 MW-class combined-cycle units for power generation, as well as very low NOv in the lean premixed combustion mode with natural gas fuel. They also account for virtually all commercial aeropropulsion systems, in which case kerosene-based fuel is used. To meet future NOv and CO regulations, a higher level

SANJAY M. CORREA

1993-01-01

183

Engine combustion control at low loads via fuel reactivity stratification  

DOEpatents

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

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

2014-10-07

184

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

185

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

186

Performance of a flameless combustion furnace using biogas and natural gas.  

PubMed

Flameless combustion technology has proved to be flexible regarding the utilization of conventional fuels. This flexibility is associated with the main characteristic of the combustion regime, which is the mixing of the reactants above the autoignition temperature of the fuel. Flameless combustion advantages when using conventional fuels are a proven fact. However, it is necessary to assess thermal equipments performance when utilizing bio-fuels, which usually are obtained from biomass gasification and the excreta of animals in bio-digesters. The effect of using biogas on the performance of an experimental furnace equipped with a self-regenerative Flameless burner is reported in this paper. All the results were compared to the performance of the system fueled with natural gas. Results showed that temperature field and uniformity are similar for both fuels; although biogas temperatures were slightly lower due to the larger amount of inert gases (CO(2)) in its composition that cool down the reactions. Species patterns and pollutant emissions showed similar trends and values for both fuels, and the energy balance for biogas showed a minor reduction of the efficiency of the furnace; this confirms that Flameless combustion is highly flexible to burn conventional and diluted fuels. Important modifications on the burner were not necessary to run the system using biogas. Additionally, in order to highlight the advantages of the Flameless combustion regime, some comparisons of the burner performance working in Flameless mode and working in conventional mode are presented. PMID:19944602

Colorado, A F; Herrera, B A; Amell, A A

2010-04-01

187

Indirect-fired gas turbine dual fuel cell power cycle  

DOEpatents

A fuel cell and gas turbine combined cycle system which includes dual fuel cell cycles combined with a gas turbine cycle wherein a solid oxide fuel cell cycle operated at a pressure of between 6 to 15 atms tops the turbine cycle and is used to produce CO.sub.2 for a molten carbonate fuel cell cycle which bottoms the turbine and is operated at essentially atmospheric pressure. A high pressure combustor is used to combust the excess fuel from the topping fuel cell cycle to further heat the pressurized gas driving the turbine. A low pressure combustor is used to combust the excess fuel from the bottoming fuel cell to reheat the gas stream passing out of the turbine which is used to preheat the pressurized air stream entering the topping fuel cell before passing into the bottoming fuel cell cathode. The CO.sub.2 generated in the solid oxide fuel cell cycle cascades through the system to the molten carbonate fuel cell cycle cathode.

Micheli, Paul L. (Sacramento, CA); Williams, Mark C. (Morgantown, WV); Sudhoff, Frederick A. (Morgantown, WV)

1996-01-01

188

The N.A.C.A. Combustion Chamber Gas-sampling Valve and Some Preliminary Test Results  

NASA Technical Reports Server (NTRS)

A gas sampling valve of the inertia-operated type was designed for procuring samples of the gases in the combustion chamber of internal combustion engines at identical points in successive cycles so that the analysis of the gas samples thus procured may aid in the study of the process of combustion. The operation of the valve is described. The valve was used to investigate the CO2 content of gases taken from the quiescent combustion chamber of a high speed compression-ignition engine when operating with two different multiple-orifice fuel injection nozzles. An analysis of the gas samples thus obtained shows that the state of quiescence in the combustion chamber is maintained during the combustion of the fuel.

Spanogle, J A; Buckley, E C

1933-01-01

189

Combustion of hydrocarbon fuels within porous inert media  

Microsoft Academic Search

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

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

1996-01-01

190

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

191

Oscillatory Flame Response in Acoustically Coupled Fuel Droplet Combustion  

E-print Network

internal combustion engine performance, i. standing waves inwithin engine and turbine systems. Fuel performance is ofengines in aviation and industry with the ultimate goal of reducing nitrogen oxide and sulfur emissions while fulfilling performance

Sevilla Esparza, Cristhian Israel

2013-01-01

192

Pollutant Emissions from Gasoline Combustion. 1. Dependence on Fuel  

E-print Network

-paraffins number: n for paraffins. A number of studies have been published concerning the combustion chemistry of paraffinic gasoline mechanism based on the chemistry of n-heptane and isooctanesthe two indicator fuels for octane

Utah, University of

193

Knock prediction for dual fuel engines by using a simplified combustion model.  

PubMed

The present work used a methane-air mixture chemical kinetics scheme consisting of 119 elementary reaction steps and 41 chemical species to develop a simplified combustion model for prediction of the knock in dual fuel engines. Calculated values by the model for natural gas operation showed good agreement with corresponding experimental values over a broad range of operating conditions. PMID:12958720

Fei, Shao-mei; Liu, Zhen-tao; Yan, Zhao-da

2003-01-01

194

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

NASA Technical Reports Server (NTRS)

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

Joachim, William F; Rothrock, A M

1930-01-01

195

Explosively Driven Combustion of Shock-Dispersed Fuels  

Microsoft Academic Search

The paper presents small-scale experiments with 1-g charges that explore the topic of post-detonation energy release due to the combustion of explosively dispersed fuels in the ambient air. To this end we have designed a new prototype small-scale charge, called Shock-Dispersed Fuel (SDF) charge. It consists of a lightweight, small paper cylinder filled with about one gram of a combustible

P. Neuwald

2006-01-01

196

Vaporizer design criteria for ethanol fueled internal combustion engines  

E-print Network

VAPORIZER DESIGN CRITERIA FOR ETHANOL FUELED INTERNAL COMBUSTION ENGINES A Thesis by ARACHCHI RALLAGE ARIYARATNE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1985 Major Subject: Agricultural Engineering VAPORIZER DESIGN CRITERIA FOR ETHANOL FUELED INTERNAL COMBUSTION ENGINES A Thesis by ARACHCHI RALLAGE ARIYARATNE Approved as to style and content by: Wayne A. LePori (Chairman) Bill A...

Ariyaratne, Arachchi Rallage

1985-01-01

197

Combustion of refuse derived fuel in a fluidized bed  

SciTech Connect

Power generation from Refuse Derived Fuel (RDF) is an attractive utilization technology of municipal solid waste. To explain the behavior of RDF-fired fluidized bed incinerator, the commercial size RDF was continuously burnt in a 30 x 30 cm bubbling type fluidized-bed combustor. It was found that 12 kg/h of RDF feed rate was too high feed for this test unit and the Co level was higher than 500 ppm. However, 10 kg/h of RDF was a proper feed rate and the Co level was kept under 150 ppm. Secondary air injection and changing air ratio from the pipe grid were effective for the complete combustion of RDE. It was also found that HCl concentration in flue gas was controlled by the calcium component contained in RDF and its level was decreased with decreasing the combustor temperature.

Piao, Guilin; Aono, Shigeru; Mori, Shigekatsu; Deguchi, Seiichi; Fujima, Yukihisa [Nagoya Univ. (Japan)] [Nagoya Univ. (Japan); Kondoh, Motohiro; Yamaguchi, Masataka [Toyota Motor Corp. (Japan). Plant Engineering Dept.] [Toyota Motor Corp. (Japan). Plant Engineering Dept.

1998-12-31

198

Hydrocarbon-fuel/combustion-chamber-liner materials compatibility  

NASA Technical Reports Server (NTRS)

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

Gage, Mark L.

1990-01-01

199

Combustion characteristics of GAP-coated boron particles and the fuel-rich solid propellant  

SciTech Connect

A process was employed that permits the coating of energetic glycidyl azide polymer (GAP) on the boron surface. Ignition and combustion behavior of single particle pure crystalline boron and GAP-coated boron at atmospheric pressure was studied experimentally by injecting the particles into the stream of hot gaseous environment of a flat-flame burner using premixed propane-oxygen-nitrogen gases. Chopped streak photographic observation was used to measure the ignition and combustion time. The flame temperature was fixed around 2,343 K, but under wider O{sub 2} level range than previous investigations. Measurement results show that GAP coating can shorten boron particle ignition delay time, however, the effect diminishes as the O{sub 2} level in combustion gas decreases. Possible mechanisms based on relevant reactions and heat effects were proposed. Combustion characteristics of fuel-rich solid propellants based on GAP-coated amorphous boron particles and uncoated ones were compared using different techniques such as combustion phenomena observations by a windowed strand burner, quenched propellant surface morphology analysis by scanning electron microscope, and combustion residues size analysis from the quenched particle collection bomb experiments. It was concluded that GAP-coated amorphous-boron-based fuel-rich propellants exhibit more vigorous combustion phenomena, higher burning rates, and a lesser extent of residue agglomeration than the uncoated baseline propellant. Moreover, reaction mechanisms were proposed to elucidate the combustion products obtained in this study.

Shyu, I.M. [Chung Cheng Inst. of Technology, Tashi (Taiwan, Province of China). Dept. of Applied Chemistry] [Chung Cheng Inst. of Technology, Tashi (Taiwan, Province of China). Dept. of Applied Chemistry; Liu, T.K. [Chung Shan Inst. of Science and Technology, Lungtan (Taiwan, Province of China). Chemical System Research Division] [Chung Shan Inst. of Science and Technology, Lungtan (Taiwan, Province of China). Chemical System Research Division

1995-03-01

200

Dynamic instabilities in spark-ignited combustion engines with high exhaust gas recirculation  

SciTech Connect

We propose a cycle-resolved dynamic model for combustion instabilities in spark-ignition engines operating with high levels of exhaust gas recirculation (EGR). High EGR is important for increasing fuel efficiency and implementing advanced low-emission combustion modes such as homogenous charge compression ignition (HCCI). We account for the complex combustion response to cycle-to-cycle feedback by utilizing a global probability distribution that describes the pre-spark state of in-cylinder fuel mixing. The proposed model does a good job of simulating combustion instabilities observed in both lean-fueling engine experiments and in experiments where nitrogen dilution is used to simulate some of the combustion inhibition of EGR. When used to simulate high internal EGR operation, the model exhibits a range of global bifurcations and chaos that appear to be very robust. We use the model to show that it should be possible to reduce high EGR combustion instabilities by switching from internal to external EGR. We also explain why it might be helpful to deliberately stratify the fuel in the pre-spark gas mixture. It might be possible to extend the simple approach used in this model to other chemical reaction systems with spatial inhomogeneity.

Daw, C Stuart [ORNL] [ORNL; FINNEY, Charles E A [ORNL] [ORNL

2011-01-01

201

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 missions; 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 test; and full-scale combustion tests.

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

1990-06-01

202

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

203

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

204

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 DOEs 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

205

Fuel-cycle greenhouse gas emissions from alternative fuels in Australian heavy vehicles  

NASA Astrophysics Data System (ADS)

This paper quantifies the expected pre-combustion and combustion emissions of greenhouse gases from Australian heavy vehicles using alternative fuels. We use the term exbodied emissions for these full fuel-cycle emissions. The fuels examined are low sulfur diesel (LSD), ultra-low sulfur diesel (ULS), compressed natural gas (CNG), liquefied natural gas (LNG), liquefied petroleum gas (LPG), ethanol (from lignocellulose), biodiesel and waste oil. Biodiesel and ethanol have the lowest exbodied greenhouse gas emissions (in grams greenhouse gases per kilometre travelled). Biodiesel reduces exbodied greenhouse gas emissions from 41% to 51% whereas ethanol reduces emissions by 49-55%. In fact, both emit larger quantities of CO 2 than conventional fuels, but as most of the CO 2 is from renewable carbon stocks that fraction is not counted towards the greenhouse gas emissions from the fuel. The gaseous fuels (LPG, CNG) come next with emissions that range from 88% to 92% of diesel. The emissions of greenhouse gases from diesel are reduced if waste oil is used as a diesel extender, but the processing energy required to generate LSD and ULS in Australia increase their greenhouse gas emissions compared to diesel fuel. The extra energy required liquefy and cool LNG means that it has the highest exbodied greenhouse gas emissions of the fuels that were considered.

Beer, Tom; Grant, Tim; Williams, David; Watson, Harry

206

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

SciTech Connect

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

Kakwani, R.M.; Kamo, R.

1989-01-01

207

COMBUSTION PROPERTIES AND CALCULATION HIGHER HEATING VALUES OF DIESEL FUELS  

Microsoft Academic Search

Physical, chemical, and fuel properties of diesel fuel samples were investigated in the research. Combustion heats as higher heating values (HHV) of the samples were determined experimentally and calculated from ultimate analysis data. The HHV (MJ kg) of the samples as a function of carbon (C, wt%) and hydrogen (H, wt%) was calculated from the following equation :for which the

Ayhan Demirba?

1998-01-01

208

Experimental Study of Unsupported Nonane fuel Droplet Combustion in Microgravity  

NASA Technical Reports Server (NTRS)

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

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

1999-01-01

209

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

210

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

SciTech Connect

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

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

2011-01-15

211

Optimization of a natural gas SI engine employing EGR strategy using a two-zone combustion model  

Microsoft Academic Search

Natural gas has been recently used as an alternative to conventional fuels in order to satisfy some environmental and economical concerns. In this study, a natural gas spark-ignition engine employing cooled exhaust gas recirculation (EGR) strategy in a high pressure inlet condition was optimized. Both engine compression ratio and start of combustion timing were optimized in order to obtain the

Amr Ibrahim; Saiful Bari

2008-01-01

212

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation  

E-print Network

Economic Potential of Biomass Based Fuels for Greenhouse Gas Emission Mitigation Uwe A. Schneider Energy, Biofuel Economics, Biomass Power Plants, Greenhouse Gas Emission Mitigation, Short Rotation Woody Words): Use of biofuels diminishes fossil fuel combustion thereby also reducing net greenhouse gas

McCarl, Bruce A.

213

Combustion characterization of beneficiated coal-based fuels  

SciTech Connect

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

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

1990-11-01

214

Orifices For Fuel-Film Cooling Of Combustion Chamber  

NASA Technical Reports Server (NTRS)

Boundary-layer film of fuel flows along wall of combustion chamber mentioned in article, "Rhenium-Foil Witness Cylinders" (NPO-18224), cooling wall and neutralizing excess of oxidizer in vicinity of wall. Enters chamber through 16 small, replaceable nozzles placed around periphery of fuel-and-oxidizer injector. Adjusted, independently of main injected flow of fuel and oxidizer, by selection of nozzle passing larger or smaller flow.

Knight, B. L.

1992-01-01

215

Exhaust gas recirculation control system for internal combustion engine  

Microsoft Academic Search

An exhaust gas recirculation control system for controlling the amount of exhaust gas subjected to recirculation to the air inlet depending on the amount of inlet air of an internal combustion engine is described. This system comprises a control valve disposed in an exhaust gas recirculation passage, for controlling the amount of exhaust gas recirculation, an orifice disposed in the

T. Ito; T. Nishimiya; S. Numakura; M. Okumura

1980-01-01

216

Global impact of fossil fuel combustion on atmospheric NO x Larry W. Horowitz  

E-print Network

Global impact of fossil fuel combustion on atmospheric NO x Larry W. Horowitz Advanced Study University, Cambridge, MA 02138 (email djj@io.harvard.edu) #12; Abstract. Fossil fuel combustion of fossil fuel combustion on the global distribution of NO x . In the model, we tag fossil fuel NO x and its

Jacob, Daniel J.

217

Surrogate Model Development for Fuels for Advanced Combustion Engines  

SciTech Connect

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

Anand, Krishnasamy [University of Wisconsin, Madison; Ra, youngchul [University of Wisconsin, Madison; Reitz, Rolf [University of Wisconsin; Bunting, Bruce G [ORNL

2011-01-01

218

High-pressure combustion of binary fuel sprays  

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

219

MCO combustible gas management leak test acceptance criteria  

SciTech Connect

Existing leak test acceptance criteria for mechanically sealed and weld sealed multi-canister overpacks (MCO) were evaluated to ensure that MCOs can be handled and stored in stagnant air without compromising the Spent Nuclear Fuel Project's overall strategy to prevent accumulation of combustible gas mixtures within MCO's or within their surroundings. The document concludes that the integrated leak test acceptance criteria for mechanically sealed and weld sealed MCOs (1 x 10{sup -5} std cc/sec and 1 x 10{sup -7} std cc/sec, respectively) are adequate to meet all current and foreseeable needs of the project, including capability to demonstrate compliance with the NFPA 60 Paragraph 3-3 requirement to maintain hydrogen concentrations [within the air atmosphere CSB tubes] t or below 1 vol% (i.e., at or below 25% of the LFL).

SHERRELL, D.L.

1999-05-11

220

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

NASA Astrophysics Data System (ADS)

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

Pfeil, Mark A.

221

The hydrogen-fueled internal combustion engine: a technical review  

Microsoft Academic Search

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

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

2006-01-01

222

Effect of injection pressure, exhaust gas recirculation and Swirl Ratio on autoignition, combustion and engine out emissions in a HSDI engine fueled by soybean biodiesel blend (B20)  

Microsoft Academic Search

To reduce the dependency on fossil fuels, various alternate energy sources have been considered in order to meet our daily energy requirements. Such renewable energy sources that have been the center of attention in the automotive community include Bio-fuels such as Ethanol and Biodiesel.^ In the recent past, researchers have reported different emission levels of Oxides of Nitrogen (NOx) from

Vinay Nagaraju

2008-01-01

223

Two-stage combustion for reducing pollutant emissions from gas turbine combustors  

NASA Technical Reports Server (NTRS)

Combustion and emission results are presented for a premix combustor fueled with admixtures of JP5 with neat H2 and of JP5 with simulated partial-oxidation product gas. The combustor was operated with inlet-air state conditions typical of cruise power for high performance aviation engines. Ultralow NOx, CO and HC emissions and extended lean burning limits were achieved simultaneously. Laboratory scale studies of the non-catalyzed rich-burning characteristics of several paraffin-series hydrocarbon fuels and of JP5 showed sooting limits at equivalence ratios of about 2.0 and that in order to achieve very rich sootless burning it is necessary to premix the reactants thoroughly and to use high levels of air preheat. The application of two-stage combustion for the reduction of fuel NOx was reviewed. An experimental combustor designed and constructed for two-stage combustion experiments is described.

Clayton, R. M.; Lewis, D. H.

1981-01-01

224

Evaluation of advanced combustion concepts for dry NO sub x suppression with coal-derived, gaseous fuels  

NASA Technical Reports Server (NTRS)

The emissions performance of a rich lean combustor (developed for liquid fuels) was determined for combustion of simulated coal gases ranging in heating value from 167 to 244 Btu/scf (7.0 to 10.3 MJ/NCM). The 244 Btu/scf gas is typical of the product gas from an oxygen blown gasifier, while the 167 Btu/scf gas is similar to that from an air blown gasifier. NOx performance of the rich lean combustor did not meet program goals with the 244 Btu/scf gas because of high thermal NOx, similar to levels expected from conventional lean burning combustors. The NOx emissions are attributed to inadequate fuel air mixing in the rich stage resulting from the design of the large central fuel nozzle delivering 71% of the total gas flow. NOx yield from ammonia injected into the fuel gas decreased rapidly with increasing ammonia level, and is projected to be less than 10% at NH3 levels of 0.5% or higher. NOx generation from NH3 is significant at ammonia concentrations significantly less than 0.5%. These levels may occur depending on fuel gas cleanup system design. CO emissions, combustion efficiency, smoke and other operational performance parameters were satisfactory. A test was completed with a catalytic combustor concept with petroleum distillate fuel. Reactor stage NOx emissions were low (1.4g NOx/kg fuel). CO emissions and combustion efficiency were satisfactory. Airflow split instabilities occurred which eventually led to test termination.

Beebe, K. W.; Symonds, R. A.; Notardonato, J. J.

1982-01-01

225

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

SciTech Connect

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

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

1980-02-27

226

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

227

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

228

Lean stability augmentation study. [on gas turbine combustion chambers  

NASA Technical Reports Server (NTRS)

An analytical conceptual design study and an experimental test program were conducted to investigate techniques and develop technology for improving the lean combustion limits of premixing, prevaporizing combustors applicable to gas turbine engine main burners. The use of hot gas pilots, catalyzed flameholder elements, and heat recirculation to augment lean stability limits was considered in the conceptual design study. Tests of flameholders embodying selected concepts were conducted at a pressure of 10 arm and over a range of entrance temperatures simulating conditions to be encountered during stratospheric cruise. The tests were performed using an axisymmetric flametube test rig having a nominal diameter of 10.2 cm. A total of sixteen test configurations were examined in which lean blowout limits, pollutant emission characteristics, and combustor performance were evaluated. The use of a piloted perforated plate flameholder employing a pilot fuel flow rate equivalent to 4 percent of the total fuel flow at a simulated cruise condition resulted in a lean blowout equivalence ratio of less than 0.25 with a design point (T sub zero = 600k, Phi = 0.6) NOx emission index of less than 1.0 g/kg.

Mcvey, J. B.; Kennedy, J. B.

1979-01-01

229

FUEL GAS ENVIRONMENTAL IMPACT  

EPA Science Inventory

The report gives results of continued investigation and further definition of the potential environmental and economic benefits of integrated coal gasification/gas cleanup/combined gas and steam cycle power plants. Reported refinements in plant operating characteristics lower hea...

230

Comparing the greenhouse gas emissions from three alternative waste combustion concepts  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Significant GHG reductions are possible by efficient WtE technologies. Black-Right-Pointing-Pointer CHP and high power-to-heat ratio provide significant GHG savings. Black-Right-Pointing-Pointer N{sub 2}O and coal mine type are important in LCA GHG emissions of FBC co-combustion. Black-Right-Pointing-Pointer Substituting coal and fuel oil by waste is beneficial in electricity and heat production. Black-Right-Pointing-Pointer Substituting natural gas by waste may not be reasonable in CHP generation. - Abstract: Three alternative condensing mode power and combined heat and power (CHP) waste-to-energy concepts were compared in terms of their impacts on the greenhouse gas (GHG) emissions from a heat and power generation system. The concepts included (i) grate, (ii) bubbling fluidised bed (BFB) and (iii) circulating fluidised bed (CFB) combustion of waste. The BFB and CFB take advantage of advanced combustion technology which enabled them to reach electric efficiency up to 35% and 41% in condensing mode, respectively, whereas 28% (based on the lower heating value) was applied for the grate fired unit. A simple energy system model was applied in calculating the GHG emissions in different scenarios where coal or natural gas was substituted in power generation and mix of fuel oil and natural gas in heat generation by waste combustion. Landfilling and waste transportation were not considered in the model. GHG emissions were reduced significantly in all of the considered scenarios where the waste combustion concepts substituted coal based power generation. With the exception of condensing mode grate incinerator the different waste combustion scenarios resulted approximately in 1 Mton of fossil CO{sub 2}-eq. emission reduction per 1 Mton of municipal solid waste (MSW) incinerated. When natural gas based power generation was substituted by electricity from the waste combustion significant GHG emission reductions were not achieved.

Vainikka, Pasi, E-mail: pasi.vainikka@vtt.fi [VTT, Koivurannantie 1, FIN 40101 Jyvaeskylae (Finland); Tsupari, Eemeli; Sipilae, Kai [VTT, Koivurannantie 1, FIN 40101 Jyvaeskylae (Finland); Hupa, Mikko [Aabo Akademi Process Chemistry Centre, Piispankatu 8, FIN 20500 Turku (Finland)

2012-03-15

231

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

SciTech Connect

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

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

2007-07-01

232

Gas only nozzle fuel tip  

DOEpatents

A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

Bechtel, William Theodore (Scotia, NY); Fitts, David Orus (Ballston Spa, NY); DeLeonardo, Guy Wayne (Glenville, NY)

2002-01-01

233

A comprehensive combustion model for biodiesel-fueled engine simulations  

NASA Astrophysics Data System (ADS)

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

Brakora, Jessica L.

234

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

235

Synthesis gas use in internal combustion engines.  

E-print Network

??The objective of this dissertation was to investigate the combustion characteristics of a compression ignition, spark ignition, and homogeneous charge compression ignition engine operating on (more)

Bika, Anil Singh

2010-01-01

236

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

237

Design and performance of a pressurized cyclone combustor (PCC) for high and low heating value gas combustion  

Microsoft Academic Search

The combustion difficulties for low heating value (LHV) gases derived from biomass fuels via a gasification process have led to more investigations into LHV gas combustors. Cyclone combustors provide good air\\/fuel mixing with long residence times. In this study, a small-scale pressurized cyclone combustor (PCC) was designed and optimized using computational fluid dynamics (CFD) simulation. The PCC, along with a

K. A. Al-attab; Z. A. Zainal

2011-01-01

238

Muffler and exhaust gas purifier for internal combustion engines  

Microsoft Academic Search

An internal combustion engine exhaust gas muffler and purifier with segmented hollow shell and removable middle segment are described. The shell has an upstream exhaust gas expansion chamber, a downstream sound-absorbing and sound-collecting chamber, and a middle, removable cartridge receiving housing. The cartridge is filled with small particles of exhaust gas purifying material. 2 claims, 9 figures.

Ignoffo

1977-01-01

239

Kinetic Modeling of Combustion Characteristics of Real Biodiesel Fuels  

SciTech Connect

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

Naik, C V; Westbrook, C K

2009-04-08

240

Global impact of fossil fuel combustion on atmospheric NOx Larry W. Horowitz  

E-print Network

Global impact of fossil fuel combustion on atmospheric NOx Larry W. Horowitz Advanced Study Program, MA 02138 (email djj@io.harvard.edu) #12;Abstract. Fossil fuel combustion is the largest global source-dimensional model of tropospheric chemistry and transport to study the impact of fossil fuel combustion

Jacob, Daniel J.

241

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

E-print Network

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

242

Combustion and deposition, erosion, and corrosion tests of coal turbine fuels  

Microsoft Academic Search

This paper discusses the results obtained from the rich-quench-lean (RQL) combustion system running on distillate fuel and coal water slurry (CWS). Estimates of fuel bound nitrogen (FBN) yield indicate that rich lean combustion is successful in reducing the yield from coal water slurry fuel to between 8% and 12%. Some improvements in combustion efficiency are required when burning coal water

C. Wilkes; R. Wenglarz; D. W. Clark

1985-01-01

243

Large Eddy Simulation of the Fuel Injection in Scramjet Combustion Chambers  

NASA Astrophysics Data System (ADS)

Fuel injection in a typical scramjet combustion chamber is a very challenging flow to characterise either in ex- perimental or computational studies. It involves multi- species compressible turbulent features with complex coherent flow structures arising as a result of sonic fuel injection transverse or inclined to the free-stream supersonic flow. In this paper the fuel injection in the HyShot- II combustion chamber is studied using an Implicit LES method employing a modified very high order accurate numerical method. To gain accurate mean inflow boundary conditions, a thermally perfect gas formulation has been employed in preliminary simulations of the inlet ramp and cowl configuration. The results of these simulations are presented and validated against wind tunnel data.

Rana, Z. A.; Thornber, B. J. R.; Drikakis, D.

2011-08-01

244

Chemically enhanced combustion of water-slurry fuels  

SciTech Connect

A method of enhancing the combustion of solid fuel/-water slurries by the addition of about 100 to 5,000 ppm of a stable water-soluble explosive, which will detonate early in the combustion process, thereby producing a secondary dispersion of fuel particles, and an 80-65% coal/20-35% water composition suitable for secondary dispersion during combustion containing about 100-5,000 ppm of a water-soluble explosive, preferably selected from at least one member of a group consisting of picric acid; alkali picrates, such as ammonium picrate, sodium picrate, potassium picrate, calcium picrate, etc., and heavy metal picrates, such as iron picrate, lead picrate, zinc picrate, etc.; guanidine and nitroguanidine. The addition of the explosive may be made to the water makeup of the slurry or may be added to the formed slurry.

Olen, K.R.

1984-06-19

245

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

246

Automotive fuels and internal combustion engines: a chemical perspective.  

PubMed

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

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

2006-04-01

247

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

248

Combustion of liquid fuels in diesel engine  

NASA Technical Reports Server (NTRS)

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

Alt, Otto

1924-01-01

249

Plasma Reforming And Partial Oxidation Of Hydrocarbon Fuel Vapor To Produce Synthesis Gas And/Or Hydrogen Gas  

DOEpatents

Methods and systems are disclosed for treating vapors from fuels such as gasoline or diesel fuel in an internal combustion engine, to form hydrogen gas or synthesis gas, which can then be burned in the engine to produce more power. Fuel vapor, or a mixture of fuel vapor and exhaust gas and/or air, is contacted with a plasma, to promote reforming reactions between the fuel vapor and exhaust gas to produce carbon monoxide and hydrogen gas, partial oxidation reactions between the fuel vapor and air to produce carbon monoxide and hydrogen gas, or direct hydrogen and carbon particle production from the fuel vapor. The plasma can be a thermal plasma or a non-thermal plasma. The plasma can be produced in a plasma generating device which can be preheated by contact with at least a portion of the hot exhaust gas stream, thereby decreasing the power requirements of the plasma generating device.

Kong, Peter C. (Idaho Falls, ID); Detering, Brent A. (Idaho Falls, ID)

2004-10-19

250

Plasma igniter for internal-combustion engines  

NASA Technical Reports Server (NTRS)

Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

Breshears, R. R.; Fitzgerald, D. J.

1978-01-01

251

Experimental study on combustion and emission characteristics of a hydrogen-enriched compressed natural gas engine under idling condition  

Microsoft Academic Search

This paper investigates the effect of various hydrogen ratios in HCNG (hydrogen enriched compressed natural gas) fuels on combustion and emission characteristics of a turbocharged spark ignition natural gas engine at idling conditions. The experiments were taken at hydrogen fractions of 0%, 30%, 55% and 75% by volume and were conducted under various operating conditions including different excess air ratio

Jiao Deng; Fanhua Ma; Shun Li; Yituan He; Mingyue Wang; Long Jiang; Shuli Zhao

2011-01-01

252

Fossil Fuels: Natural Gas  

NSDL National Science Digital Library

This lesson provides an introduction to the use of natural gas as an energy source. Topics include its advantages (cleanliness, fewer carbon emissions), disadvantages (difficulty in transport and storage), sources, and usage. There is also a discussion of the creation and production of natural gas, the United States' production and reserves, and some potential new sources (coal bed methane, methane hydrates). The lesson includes an activity in which students investigate porosity and permeability in simulated sediments.

John Pratte

253

Advanced coal-fueled gas turbine systems  

SciTech Connect

Westinghouse's Advanced Coal-Fueled Gas Turbine System Program (DE-AC2l-86MC23167) was originally split into two major phases - a Basic Program and an Option. The Basic Program also contained two phases. The development of a 6 atm, 7 lb/s, 12 MMBtu/hr slagging combustor with an extended period of testing of the subscale combustor, was the first part of the Basic Program. In the second phase of the Basic Program, the combustor was to be operated over a 3-month period with a stationary cascade to study the effect of deposition, erosion and corrosion on combustion turbine components. The testing of the concept, in subscale, has demonstrated its ability to handle high- and low-sulfur bituminous coals, and low-sulfur subbituminous coal. Feeding the fuel in the form of PC has proven to be superior to CWM type feed. The program objectives relative to combustion efficiency, combustor exit temperature, NO[sub x] emissions, carbon burnout, and slag rejection have been met. Objectives for alkali, particulate, and SO[sub x] levels leaving the combustor were not met by the conclusion of testing at Textron. It is planned to continue this testing, to achieve all desired emission levels, as part of the W/NSP program to commercialize the slagging combustor technology.

Not Available

1992-09-01

254

A test device for premixed gas turbine combustion oscillations  

SciTech Connect

This report discusses design and operation of a single-nozzle test combustor for studying lean, premixed combustion oscillations from gas turbine fuel nozzles. It was used to study oscillations from a prototype fuel nozzle that produced oscillations during testing in a commercial engine. Similar, but not identical, oscillations were recorded in the test device. Basic requirements of the device design were that the flame geometry be maintained and acoustic losses be minimized; this was achieved by using a Helmholtz resonator as the combustor geometry. Surprisingly, the combustor oscillated strongly at several frequencies, without modification of the resonator. Brief survey of operating conditions suggests that it may be helpful to characterize oscillating behavior in terms of reference velocity and inlet air temperature with the rig backpressure playing a smaller role. The preliminary results do not guarantee that the single-nozzle test device will reproduce arbitrary oscillations that occur on a complete engine test. Nozzle/nozzle interactions may complicate the response, and oscillations controlled by acoustic velocities transverse to the nozzle axis may not be reproduced in a test device that relies on a bulk Helmholtz mode. Nevertheless, some oscillations can be reproduced, and the single-nozzle test device allows both active and passive control strategies to be tested relatively inexpensively.

Richards, G.A.; Gemmen, R.S.; Yip, M.J.

1996-03-01

255

Advanced coal-fueled gas turbine systems  

Microsoft Academic Search

Several technology advances since the early coal-fueled turbine programs that address technical issues of coal as a turbine fuel have been developed in the early 1980s: Coal-water suspensions as fuel form, improved methods for removing ash and contaminants from coal, staged combustion for reducing NO emissions from fuel-bound nitrogen, and greater understanding of deposition\\/erosion\\/corrosion and their control. Several Advanced Coal-Fueled

Wenglarz

1994-01-01

256

Alternative fuels for industrial gas turbines (AFTUR)  

Microsoft Academic Search

Environmentally friendly, gas turbine driven co-generation plants can be located close to energy consumption sites, which can produce their own fuel such as waste process gas or biomass derived fuels. Since gas turbines are available in a large power range, they are well suited for this application. Current gas turbine systems that are capable of burning such fuels are normally

Iskender Gkalp; Etienne Lebas

2004-01-01

257

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

258

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

259

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

SciTech Connect

A review is given of contemporary research on the hydrogen-fueled internal combustion engine. The emphasis is on light- to medium-duty engine research. We first describe hydrogen-engine fundamentals by examining the engine-specific properties of hydrogen and surveying the existing literature. Here it will be shown that, due to low volumetric efficiencies and frequent preignition combustion events, the power densities of premixed or port-fuel-injected hydrogen engines are diminished relative to gasoline-fueled engines. Significant progress has been made in the development of advanced hydrogen engines with improved power densities. We discuss several examples and their salient features. Finally, we consider the overall progress made and provide suggestions for future work.

Steeper, Richard R.; White, Christopher M.; Lutz, Andrew E.

2005-05-01

260

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

261

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

262

Comparison of Different Global Reaction Mechanisms for MILD Combustion of Natural Gas  

Microsoft Academic Search

Emissions of nitrogen oxides from fossil fuel combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. MILD (Moderate and Intensive Low oxygen Dilution) combustion is a promising technology to decrease pollutant emissions and to improve combustion efficiency. A combination of air preheating and fuel dilution with combustion

Ju Pyo Kim; Uwe Schnell; Gnter Scheffknecht

2008-01-01

263

Combustion tests of a turbine simulator burning low Btu fuel and a rich-quench-lean combustor  

SciTech Connect

The integrated gasification combined cycle (IGCC) concept represents a highly efficient and environmentally compatible advanced coal fueled power generation technology. When IGCC is coupled with high temperature desulfurization, or hot gas cleanup (HGCU), the efficiency and cost advantage of IGCC is further improved with respect to systems based on conventional low temperature gas cleanup. 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) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle; and (3) measurement of NO{sub x}, CO, and particulate emissions. 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 work 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.

1993-09-01

264

Combustion tests of a turbine simulator burning low Btu fuel and a rich-quench-lean combustor  

SciTech Connect

The integrated gasification combined cycle (IGCC) concept represents a highly efficient and environmentally compatible advanced coal fueled power generation technology. When IGCC is coupled with high temperature desulfurization, or hot gas cleanup (HGCU), the efficiency and cost advantage of IGCC is further improved with respect to systems based on conventional low temperature gas cleanup. 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) characterization of particulates in the fuel as well as deposits in the fuel nozzle, combustor, and first stage nozzle; and (3) measurement of NO{sub x}, CO, and particulate emission. In a related project, a reduced scale rich-quench-lean (RQL) gas turbine combustor has been designed, constructed, and fires with simulated low Btu fuel. The overall objective of this work is to develop an RQL combustor with lower conversion of fuel bound nitrogen (FBN) to NO{sub x} than a conventional combustor.

Abuaf, N.; Feitelberg, A.S.; Hung, S.L.; Najewicz, D.J.; Samuels, M.S. [GE Environmental Services, Inc., Lebanon, PA (United States)

1993-06-01

265

Fuels Containing Methane of Natural Gas in Solution  

NASA Technical Reports Server (NTRS)

While exploring ways of producing better fuels for propulsion of a spacecraft on the Mars sample return mission, a researcher at Johnson Space Center (JSC) devised a way of blending fuel by combining methane or natural gas with a second fuel to produce a fuel that can be maintained in liquid form at ambient temperature and under moderate pressure. The use of such a blended fuel would be a departure for both spacecraft engines and terrestrial internal combustion engines. For spacecraft, it would enable reduction of weights on long flights. For the automotive industry on Earth, such a fuel could be easily distributed and could be a less expensive, more efficient, and cleaner-burning alternative to conventional fossil fuels. The concept of blending fuels is not new: for example, the production of gasoline includes the addition of liquid octane enhancers. For the future, it has been commonly suggested to substitute methane or compressed natural gas for octane-enhanced gasoline as a fuel for internal-combustion engines. Unfortunately, methane or natural gas must be stored either as a compressed gas (if kept at ambient temperature) or as a cryogenic liquid. The ranges of automobiles would be reduced from their present values because of limitations on the capacities for storage of these fuels. Moreover, technical challenges are posed by the need to develop equipment to handle these fuels and, especially, to fill tanks acceptably rapidly. The JSC alternative to provide a blended fuel that can be maintained in liquid form at moderate pressure at ambient temperature has not been previously tried. A blended automotive fuel according to this approach would be made by dissolving natural gas in gasoline. The autogenous pressure of this fuel would eliminate the need for a vehicle fuel pump, but a pressure and/or flow regulator would be needed to moderate the effects of temperature and to respond to changing engine power demands. Because the fuel would flash as it entered engine cylinders, relative to gasoline, it would disperse more readily and therefore would mix with air more nearly completely. As a consequence, this fuel would burn more nearly completely (and, hence, more cleanly) than gasoline does. The storage density of this fuel would be similar to that of gasoline, but its energy density would be such that the mileage (more precisely, the distance traveled per unit volume of fuel) would be greater than that of either gasoline or compressed natural gas. Because the pressure needed to maintain the fuel in liquid form would be more nearly constant and generally lower than that needed to maintain compressed natural gas in liquid form, the pressure rating of a tank used to hold this fuel could be lower than that of a tank used to hold compressed natural gas. A mixture of natural gas and gasoline could be distributed more easily than could some alternative fuels. A massive investment in new equipment would not be necessary: One could utilize the present fuel-distribution infrastructure and could blend the gasoline and natural gas at almost any place in the production or distribution process - perhaps even at the retail fuel pump. Yet another advantage afforded by use of a blend of gasoline and natural gas would be a reduction in the amount of gasoline consumed. Because natural gas costs less than gasoline does and is in abundant supply in the United States, the cost of automotive fuel and the demand for imported oil could be reduced.

Sullivan, Thomas A.

2004-01-01

266

Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions  

SciTech Connect

A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

Biruduganti, Munidhar S. (Naperville, IL); Gupta, Sreenath Borra (Naperville, IL); Sekar, R. Raj (Naperville, IL); McConnell, Steven S. (Shorewood, IL)

2008-11-25

267

Explosively Driven Combustion of Shock-Dispersed Fuels  

NASA Astrophysics Data System (ADS)

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

Neuwald, P.

2006-07-01

268

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

269

Numerical Analysis of Combustion in a Compressed Natural Gas Direct Injection Engine  

NASA Astrophysics Data System (ADS)

Compressed Natural Gas (CNG) direct injection engine has many advantages for the reduction of CO2 emission. For further improvement of those engines, a numerical simulation technique has been developed for the analysis of combustion process. Prior to an in-cylinder calculation, the wall function was modified to improve the accuracy of the wall heat loss. Then the nozzle-to-cylinder entire calculation was performed. Good agreements were obtained in comparison with the experiment for the behavior of impinging jets. This method was applied to the analysis of the difference of combustion processes between CNG and conventional gasoline direct-injection engines. It is accordingly found that the velocity and the turbulence of in-cylinder gas are increased by the fuel injection into CNG engine and thus the combustion speed is enhanced significantly.

Nomura, Yoshihiro; Inagaki, Hideto; Tsukasaki, Yukihiro

270

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

271

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

PubMed

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

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

2002-10-14

272

Nitrogen Oxides, Sulfur Trioxide, and Mercury Emissions during Oxy-fuel Fluidized Bed Combustion of Victorian Brown Coal.  

PubMed

This study investigates, for the first time, the NOx, N2O, SO3, and Hg emissions from combustion of a Victorian brown coal in a 10 kWth fluidized bed unit under oxy-fuel combustion conditions. Compared to air combustion, lower NOx emissions and higher N2O formation were observed in the oxy-fuel atmosphere. These NOx reduction and N2O formations were further enhanced with steam in the combustion environment. The NOx concentration level in the flue gas was within the permissible limit in coal-fired power plants in Victoria. Therefore, an additional NOx removal system will not be required using this coal. In contrast, both SO3 and gaseous mercury concentrations were considerably higher under oxy-fuel combustion compared to that in the air combustion. Around 83% of total gaseous mercury released was Hg(0), with the rest emitted as Hg(2+). Therefore, to control harmful Hg(0), a mercury removal system may need to be considered to avoid corrosion in the boiler and CO2 separation units during the oxy-fuel fluidized-bed combustion using this coal. PMID:25402169

Roy, Bithi; Chen, Luguang; Bhattacharya, Sankar

2014-12-16

273

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

274

Fuel injector nozzle for an internal combustion engine  

DOEpatents

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

275

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)

2008-11-04

276

Fuel injector nozzle for an internal combustion engine  

DOEpatents

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)

2007-11-06

277

Fuel Injector Nozzle For An Internal Combustion Engine  

DOEpatents

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)

2006-04-25

278

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

NASA Technical Reports Server (NTRS)

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

Riedler, A

1923-01-01

279

Internal combustion engine in which compressed fuel mixture is combusted externally of the cylinders of the engine in a rotating combustion chamber  

SciTech Connect

An internal combustion engine is described comprising a cylinder body having a pair of adjoining first and second cylinders, a reciprocable piston in each cylinder, first valve means for introducing a fuel mixture in the first cylinder, second valve means for discharge of exhaust gases from the second cylinder, a combustion chamber mounted adjacent the cylinder body for movement between the cylinders and communicating in one position with the first cylinder and in a second position with the second cylinder, the combustion chamber receiving compressed fuel mixture from the first cylinder in the one position, and means for igniting the compressed fuel mixture in the combustion chamber as the chamber moves from the first to the second position, the combustion chamber delivering combusted fuel mixture to the second cylinder in the second position.

Staheli, A.A.

1988-04-26

280

Muffler for exhaust gas from an internal combustion engine  

Microsoft Academic Search

A muffler is described for the exhaust gas of an internal combustion engine, the muffler having an inlet and an outlet for exhaust gas and further compromising a casing and a cylindrical sound absorbing body comprising a fibrous material and extending through the casing and having an inner cylindrical surface, and a heat resistant paint formed on the inner cylindrical

H. Tanaka; M. Sekiya; F. Uchikawa

1986-01-01

281

Muffler for exhaust gas from internal combustion engine  

Microsoft Academic Search

A muffler for exhaust gas of an internal combustion engine is described comprising: (a) a casing having an inlet and an outlet for receiving an expelling, respectively, the exhaust gas, (b) a cylindrical sound-absorbing body comprising, (i) a first, perforated pipe having openings formed therein, (ii) a cylindrical porous sound-absorbing material concentrically surrounding the perforated pipe, (iii) and a thin

H. Tanaka; M. Sekiya; F. Uchikawa

1987-01-01

282

Catalyst for treating exhaust gas from an internal combustion engine  

Microsoft Academic Search

This invention is directed to an equilibrium catalyst for treating oxides of nitrogen, carbon monoxide and unburned hydrocarbons found in an exhaust gas stream from an internal combustion engine. The catalyst includes a substrate, a selective three-way equilibrium catalyst, an oxygen storage material component for maintaining the activity of the equilibrium catalyst during momentary excursions of the exhaust gas stream

H. S. Gandhi; M. Shelef

1980-01-01

283

Exhaust gas recirculation valve device for an internal combustion engine  

Microsoft Academic Search

An exhaust gas recirculation valve device is described for an exhaust gas cleaning apparatus of an internal combustion engine for an automobile. A diaphragm mechanism is mounted on a body for operating the valve device. The diaphragm mechanism has a diaphragm and has, on both sides of the diaphragm, chambers which should be connected to the respective engine ports. One

M. Ando; K. Katow; M. Yamazaki

1977-01-01

284

Muffler for exhaust gas from internal combustion engine  

Microsoft Academic Search

A muffler is described for exhaust gas of an internal combustion engine comprising, (a) a casing having an inlet and an outlet for receiving and expelling, respectively, the exhaust gas, (b) a cylindrical sound-absorbing body comprising, (i) a perforated pipe having openings formed therein, (ii) a cylindrical porous sound-absorbing material concentrically surrounding the perforated pipe, (iii) and a thin film

H. Tanaka; M. Sekiya; F. Uchikawa

1986-01-01

285

Combustion of ultrafine coal/water mixtures and their application in gas turbines: Final report  

SciTech Connect

The feasibility of using coal-water fuels (CWF) in gas turbine combustors has been demonstrated in recent pilot plant experiments. The demands of burning coal-water fuels with high flame stability, complete combustion, low NO/sub x/ emission and a resulting fly ash particle size that will not erode turbine blades represent a significant challenge to combustion scientists and engineers. The satisfactory solution of these problems requires that the variation of the structure of CWF flames, i.e., the fields of flow, temperature and chemical species concentration in the flame, with operating conditions is known. Detailed in-flame measurements are difficult at elevated pressures and it has been proposed to carry out such experiments at atmospheric pressure and interpret the data by means of models for gas turbine combustor conditions. The research was carried out in five sequential tasks: cold flow studies; studies of conventional fine-grind CWF; combustion studies with ultrafine CWF fuel; reduction of NO/sub x/ emission by staged combustion; and data interpretation-ignition and radiation aspects. 37 refs., 61 figs., 9 tabs.

Toqan, M.A.; Srinivasachar, S.; Staudt, J.; Varela, F.; Beer, J.M.

1987-10-01

286

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

287

Effect of gas composition on octane number of natural gas fuels. Topical report, December 1991-March 1992  

SciTech Connect

Variations in the composition of natural gas fuels are recognized to have a significant impact on the performance of internal combustion engines. In particular, the knock resistance of the fuel is governed by its gas composition. The octane number is a standard measure of the knock resistance of a fuel, and several gas blends were tested to determine their octane numbers. Octane number of natural gas fuels was found to be dependent on gas composition. Several correlations were found between gas composition and the octane number of a fuel, which allow prediction of the motor octane number if gas composition is known. In particular, a good correlation was found between the hydrogen-carbon ratio of the fuel and the octane number. Correlations were also found between measured motor octane numbers and measured methane numbers, as well as between motor octane numbers and predicted methane numbers.

Kubesh, J.T.

1992-05-01

288

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

NASA Astrophysics Data System (ADS)

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

Singh, Bhupinder

289

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

290

Hydrogen-fueled internal combustion engines  

Microsoft Academic Search

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

Sebastian Verhelst; Thomas Wallner

2009-01-01

291

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

292

The Effect of Fuel Types on Porous Alumina Produced via Soft Combustion Reaction for Implant Applications  

Microsoft Academic Search

This article describes the effects of fuel types on the porous structure of alumina produced using a soft combustion reaction. There are several combustion parameters that could affect the porous structure of the alumina produced such as fuel-to-oxidizer ratios, ignition temperature, and type of fuels. In this study, the effect of fuel types on alumina properties was studied. Citric acid,

Radin Shafinaz Jamil; Khairunisak Abdul Razak; Nurfateen Fakhariah Ahmad; Hasmaliza Mohamad

2011-01-01

293

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

Microsoft Academic Search

In this study, the combustion characteristics and emissions of two different petroleum diesel fuels (No. 1 and No. 2) and biodiesel from soybean oil were compared. The tests were performed at steady state conditions in a four-cylinder turbocharged DI diesel engine at full load at 1400-rpm engine speed. The experimental results compared with No. 2 diesel fuel showed that biodiesel

Mustafa Canakci

2007-01-01

294

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

SciTech Connect

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

Cappelli, Mark; Mungal, M Godfrey

2014-10-28

295

Combustion Instability in an Acid-Heptane Rocket with a Pressurized-Gas Propellant Pumping System  

NASA Technical Reports Server (NTRS)

Results of experimental measurements of low-frequency combustion instability of a 300-pound thrust acid-heptane rocket engine were compared to the trends predicted by an analysis of combustion instability in a rocket engine with a pressurized-gas propellant pumping system. The simplified analysis, which assumes a monopropellant model, was based on the concept of a combustion the delay occurring from the moment of propellant injection to the moment of propellant combustion. This combustion time delay was experimentally measured; the experimental values were of approximately half the magnitude predicted by the analysis. The pressure-fluctuation frequency for a rocket engine with a characteristic length of 100 inches and operated at a combustion-chamber pressure of 280 pounds per square inch absolute was 38 cycles per second; the analysis indicated. a frequency of 37 cycles per second. Increasing combustion-chamber characteristic length decreased the pressure-fluctuation frequency, in conformity to the analysis. Increasing the chamber operating pressure or increasing the injector pressure drop increased the frequency. These latter two effects are contrary to the analysis; the discrepancies are attributed to the conflict between the assumptions made to simplify the analysis and the experimental conditions. Oxidant-fuel ratio had no apparent effect on the experimentally measured pressure-fluctuation frequency for acid-heptane ratios from 3.0 to 7.0. The frequencies decreased with increased amplitude of the combustion-chamber pressure variations. The analysis indicated that if the combustion time delay were sufficiently short, low-frequency combustion instability would be eliminated.

Tischler, Adelbert O.; Bellman, Donald R.

1951-01-01

296

Control of mercury vapor emissions from combustion flue gas  

Microsoft Academic Search

Goal, Scope and BackgroundMercury (Hg) emission from combustion flue gas is a significant environmental concern due to its toxicity and high volatility.\\u000a A number of the research efforts have been carried out in the past decade exploiting mercury emission, monitoring and control\\u000a from combustion flue gases. Most recently, increasing activities are focused on evaluating the behavior of mercury in coal

Rong Yan; David Tee Liang; Joo Hwa Tay

2003-01-01

297

Synthesis of Diopside by Solution Combustion Process Using Glycine Fuel  

NASA Astrophysics Data System (ADS)

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

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

298

Exhaust gas recirculation system for an internal combustion engine  

SciTech Connect

An exhaust gas recirculation system for an internal combustion engine comprises an exhaust driven turbocharger having a low pressure turbine outlet in fluid communication with an exhaust gas conduit. The turbocharger also includes a low pressure compressor intake and a high pressure compressor outlet in communication with an intake air conduit. An exhaust gas recirculation conduit fluidly communicates with the exhaust gas conduit to divert a portion of exhaust gas to a low pressure exhaust gas recirculation branch extending between the exhaust gas recirculation conduit and an engine intake system for delivery of exhaust gas thereto. A high pressure exhaust gas recirculation branch extends between the exhaust gas recirculation conduit and the compressor intake and delivers exhaust gas to the compressor for mixing with a compressed intake charge for delivery to the intake system.

Wu, Ko-Jen

2013-05-21

299

Lean-limit combustion instabilities of a lean premixed prevaporized gas turbine combustor  

Microsoft Academic Search

One type of low-frequency combustion instability was studied in a lean premixed prevaporized (LPP) gas turbine combustor experiment that was operated at elevated pressures using liquid Jet-A fuel. This intense low-frequency (15Hz) instability is called a lean-limit instability, while in other papers it has been called a cold tone, an incipient blowout instability or an entropy wave. High-speed movies identified

Sulabh K. Dhanuka; Jacob E. Temme; James F. Driscoll

2011-01-01

300

Unburned Gas Temperatures in an Internal Combustion Engine. I:Cars Temperature Measurements  

Microsoft Academic Search

Broadband,coherent anti-Stokes Raman scattering (CARS) measurements of unburned gas temperatures have been performed in an internal combustion engine.The engine is fueled with n-butane and air and is operated under both knocking and non-knocking conditons.Temperatures are determined by fitting calculated CARS spectra to experimentally obtained,cycle-averaged nitrogen CARS spectra.The accuracy of the fitted temperature depends on a number of factors,including the modeling

Robert P. Lucht; Richard E. Teets; Robert M. Green; Richard E. Palmer; Colin R. Ferguson

1987-01-01

301

Combustion Properties of Biologically Sourced Alternative Fuels  

NASA Astrophysics Data System (ADS)

The effects of pressure on various properties of ten different syngas fueled flames were analyzed using one and two dimensional simulations. One-dimensional premixed flames were modeled in CANTERA. Flame speed, adiabatic flame temperature and thermal diffusivity as functions of equivalence ratio and pressure were quantified for the fuels using four chemical kinetic mechanisms. Data from the different mechanisms displayed good agreement with data from previous experimental benchmarks. Two-dimensional axisymmetric co-flow flames were simulated in a state of the art computational framework for modeling laminar flames. Flame structure comparisons were made with past experimental and numerical results as well as with theoretical predictions. Good agreement in stoichiometric flame height was observed with past theoretical and numerical flame height measurements. Visible flame heights had little correlation with the stoichiometric flame heights. The flame radius was also noted to be proportional to p -0.35 at high pressures instead of p-0.5 as predicted by theory.

Barnwal, Abhishek

302

Burning clean fuel gas improves energetic efficiency  

Microsoft Academic Search

One the most critical problems faced by refineries nowadays is the continuous increasing of legislation urging emissions reductions specifically SO2, NOx, and particles. Therefore there is a substantial need for refineries to burn fuel gas instead of fuel oil and avoiding, if possible, the use of imported natural gas. The refinery case study presents a substantial excess of fuel gas

Andr Fonseca; Manuel L. C. Tavares; Lusa A. C. N. Gomes

2010-01-01

303

Combustion Dynamics and Control for Ultra Low Emissions in Aircraft Gas-Turbine Engines  

NASA Technical Reports Server (NTRS)

Future aircraft engines must provide ultra-low emissions and high efficiency at low cost while maintaining the reliability and operability of present day engines. The demands for increased performance and decreased emissions have resulted in advanced combustor designs that are critically dependent on efficient fuel/air mixing and lean operation. However, all combustors, but most notably lean-burning low-emissions combustors, are susceptible to combustion instabilities. These instabilities are typically caused by the interaction of the fluctuating heat release of the combustion process with naturally occurring acoustic resonances. These interactions can produce large pressure oscillations within the combustor and can reduce component life and potentially lead to premature mechanical failures. Active Combustion Control which consists of feedback-based control of the fuel-air mixing process can provide an approach to achieving acceptable combustor dynamic behavior while minimizing emissions, and thus can provide flexibility during the combustor design process. The NASA Glenn Active Combustion Control Technology activity aims to demonstrate active control in a realistic environment relevant to aircraft engines by providing experiments tied to aircraft gas turbine combustors. The intent is to allow the technology maturity of active combustion control to advance to eventual demonstration in an engine environment. Work at NASA Glenn has shown that active combustion control, utilizing advanced algorithms working through high frequency fuel actuation, can effectively suppress instabilities in a combustor which emulates the instabilities found in an aircraft gas turbine engine. Current efforts are aimed at extending these active control technologies to advanced ultra-low-emissions combustors such as those employing multi-point lean direct injection.

DeLaat, John C.

2011-01-01

304

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

305

DEVELOPMENT OF SAMPLING AND ANALYTICAL METHODS FOR THE MEASUREMENT OF NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION SOURCES  

EPA Science Inventory

The report documents the technical approach and results achieved while developing a grab sampling method and an automated, on-line gas chromatography method suitable to characterize nitrous oxide (N2O) emissions from fossil fuel combustion sources. The two methods developed have...

306

DEVELOPMENT OF SAMPLING AND ANALYTICAL METHODS FOR THE MEASUREMENT OF NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION SOURCES  

EPA Science Inventory

The report documents the technical approach and results achieved while developing a grab sampling method and an automated, on-line gas chromatography method suitable to characterize nitrous oxide (N2O) emissions from fossil fuel combustion sources. he two methods developed have b...

307

The Implications of Fossil Fuel Combustion for Climate Change  

Microsoft Academic Search

Emissions from fossil fuel combustion alter the composition of the atmosphere and have been touted as a major cause of climate change. The amount of CO2 in the atmosphere, for example, has increased by more than 30% since pre-industrial times. Average global surface temperature has increased by approximately 0.6 0.2 C since the late 19th Century, and surface temperature

Kristy E. Ross; Stuart J. Piketh

308

Fuel economy drive favours gas turbine power systems  

NASA Astrophysics Data System (ADS)

Changing market and fuel supply conditions tending to favor more widespread use of gas turbine power systems (GTPS) are examined. Two decades of changes in the costs of steam generating plant, labor, materials, and combustion turbine plants are surveyed, and attention is centered on changes in fuel costs and returns on investment. Combined power plants incorporating a GTPS or GTPS acting alone are considered and compared. Covering of peak load and reserve margins by GTPS, combinations of GTPS with hydroelectric and pumped storage, repowering arrangements (incorporating a combustion turbine with heat recovery equipment to make use of the waste heat from an existing facility), and more economical use of fuel oils in existing systems when GTPS become part of the picture are dealt with.

Finizio, A. F.

1977-03-01

309

Combustion of Illinois coals and chars with natural gas. Final technical report, September 1, 1991--August 31, 1992  

SciTech Connect

Combined combustion of coal and natural gas offers advantages compared to burning coal or natural gas alone. For example, low volatile coals (or chars) derived from treatment or gasification processes can be of limited use due to their poor flammability characteristics. However, the use of natural gas in conjunction with the solid fuel can provide the necessary ``volatiles`` to enhance the combustion. Also, natural gas provides a clean cofiring fuel source which can enhance the usefulness of coals with high sulfur content. Addition of natural gas may reduce SO{sub x} emissions through increased sulfur retention in the ash and reduce NO{sub x} emissions by varying local stoichiometry and temperature levels. This research program addresses the contributions and the mechanisms of cofiring natural gas with Illinois coal through studies of particle ignition, burning rates and ash characterization.

Buckius, R.O.; Peters, J.E.; Krier, H. [Illinois Univ., Urbana-Champaign, IL (United States)

1992-12-31

310

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

311

Combustion Properties of Gas-Generating Pyrotechnics  

Microsoft Academic Search

This work focuses particularly on solid energetic materials designed to produce high-pressure gas for pressurizing or inflating devices. In coot gas generators sodium azide is often used. Unfortunately, this chemical exhibits drawbacks concerning toxicity and yield of gas. Another gas-generating agent is double base propellant, which has traditionally been used in the rocket-industry. However, it delivers toxic and reactive gases

K. ENGELEN; M. H. LEFEBVRE; J. DE RUYCK

2001-01-01

312

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

313

Greenhouse gas emissions from selected alternative transportation fuels market niches  

SciTech Connect

The incremental worldwide effects on greenhouse gases are estimated for the substitution of natural gas- or methanol-based light-duty vehicles for current gasoline-based vehicles in the United States. The effects are estimated on a per-vehicle mile basis, holding acceleration, passenger capacity, engine technology, and range of the vehicle constant. The relative merits of natural gas- or methanol-based vehicles for commuting and other household vehicle market niches are considered. In terms of net global greenhouse gas emissions, the replacement of crude-oil-derived gasoline by non-gasoline fuels derived from natural gas is superior to the use of gasoline derived from natural gas. The transition paths from oil to natural-gas-based light-duty vehicle fuels is examined, considering the effects of the substitution of currently flared natural gas for crude oil as the raw material for transition transportation fuels. Greenhouse gas emissions arising from the following raw material pathways are compared: oil to gasoline; natural gas to the atmosphere, flared combustion products to the atmosphere, compressed natural gas in vehicles, methanol in vehicles, methyl tert-butyl ether in vehicles, and gasoline in vehicles; and coal to methanol. 33 refs., 6 figs., 2 tabs.

Santini, D.J.; DeLuchi, M.A.; Vyas, A.; Walsh, M.

1989-01-01

314

Compatibility of alternative fuels with advanced automotive gas turbine and stirling engines. A literature survey  

NASA Astrophysics Data System (ADS)

The application of alternative fuels in advanced automotive gas turbine and Stirling engines is discussed on the basis of a literature survey. These alternative engines are briefly described, and the aspects that will influence fuel selection are identified. Fuel properties and combustion properties are discussed, with consideration given to advanced materials and components. Alternative fuels from petroleum, coal, oil shale, alcohol, and hydrogen are discussed, and some background is given about the origin and production of these fuels. Fuel requirements for automotive gas turbine and Stirling engines are developed, and the need for certain reseach efforts is discussed. Future research efforts planned at Lewis are described.

Cairelli, J.; Horvath, D.

1981-05-01

315

Compatibility of alternative fuels with advanced automotive gas turbine and stirling engines. A literature survey  

NASA Technical Reports Server (NTRS)

The application of alternative fuels in advanced automotive gas turbine and Stirling engines is discussed on the basis of a literature survey. These alternative engines are briefly described, and the aspects that will influence fuel selection are identified. Fuel properties and combustion properties are discussed, with consideration given to advanced materials and components. Alternative fuels from petroleum, coal, oil shale, alcohol, and hydrogen are discussed, and some background is given about the origin and production of these fuels. Fuel requirements for automotive gas turbine and Stirling engines are developed, and the need for certain reseach efforts is discussed. Future research efforts planned at Lewis are described.

Cairelli, J.; Horvath, D.

1981-01-01

316

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

317

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

318

10 CFR 50.44 - Combustible gas control for nuclear power reactors.  

Code of Federal Regulations, 2012 CFR

...Combustible gas control for nuclear power reactors. 50.44 Section 50...Combustible gas control for nuclear power reactors. (a) Definitions ...boiling or pressurized water nuclear power reactor with an operating...

2012-01-01

319

10 CFR 50.44 - Combustible gas control for nuclear power reactors.  

Code of Federal Regulations, 2011 CFR

...Combustible gas control for nuclear power reactors. 50.44 Section 50...Combustible gas control for nuclear power reactors. (a) Definitions ...boiling or pressurized water nuclear power reactor with an operating...

2011-01-01

320

10 CFR 50.44 - Combustible gas control for nuclear power reactors.  

...Combustible gas control for nuclear power reactors. 50.44 Section 50...Combustible gas control for nuclear power reactors. (a) Definitions ...boiling or pressurized water nuclear power reactor with an operating...

2014-01-01

321

10 CFR 50.44 - Combustible gas control for nuclear power reactors.  

Code of Federal Regulations, 2013 CFR

...Combustible gas control for nuclear power reactors. 50.44 Section 50...Combustible gas control for nuclear power reactors. (a) Definitions ...boiling or pressurized water nuclear power reactor with an operating...

2013-01-01

322

Quantitative thermal analysis technique for combustible gas detection  

Microsoft Academic Search

The Reaction Coulometer gas chromatograph detector was adapted for thermal analysis of solids. Response is predictable for pure standards and is easily calibrated. A quantitative analysis is obtained by measuring the methods of oxygen required for combustion of gases produced by pyrolysis, even though the mixture has unknown or complex products. Therefore, the technique is suited to thermal studies of

R. A. Susott; F. Shafizadeh; T. W. Aanerud

1979-01-01

323

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

324

Power plant including an exhaust gas recirculation system for injecting recirculated exhaust gases in the fuel and compressed air of a gas turbine engine  

DOEpatents

A power plant is provided and includes a gas turbine engine having a combustor in which compressed gas and fuel are mixed and combusted, first and second supply lines respectively coupled to the combustor and respectively configured to supply the compressed gas and the fuel to the combustor and an exhaust gas recirculation (EGR) system to re-circulate exhaust gas produced by the gas turbine engine toward the combustor. The EGR system is coupled to the first and second supply lines and configured to combine first and second portions of the re-circulated exhaust gas with the compressed gas and the fuel at the first and second supply lines, respectively.

Anand, Ashok Kumar; Nagarjuna Reddy, Thirumala Reddy; Shaffer, Jason Brian; York, William David

2014-05-13

325

Impact of Fuel Interchangeability on dynamic Instabilities in Gas Turbine Engines  

SciTech Connect

Modern, low NOx emitting gas turbines typically utilize lean pre-mixed (LPM) combustion as a means of achieving target emissions goals. As stable combustion in LPM systems is somewhat intolerant to changes in operating conditions, precise engine tuning on a prescribed range of fuel properties is commonly performed to avoid dynamic instabilities. This has raised concerns regarding the use of imported liquefied natural gas (LNG) and natural gas liquids (NGLs) to offset a reduction in the domestic natural gas supply, which when introduced into the pipeline could alter the fuel BTU content and subsequently exacerbate problems such as combustion instabilities. The intent of this study is to investigate the sensitivity of dynamically unstable test rigs to changes in fuel composition and heat content. Fuel Wobbe number was controlled by blending methane and natural gas with various amounts of ethane, propane and nitrogen. Changes in combustion instabilities were observed, in both atmospheric and pressurized test rigs, for fuels containing high concentrations of propane (> 62% by vol). However, pressure oscillations measured while operating on typical LNG like fuels did not appear to deviate significantly from natural gas and methane flame responses. Mechanisms thought to produce changes in the dynamic response are discussed.

Ferguson, D.H.; Straub, D.L.; Richards, G.A.; Robey, E.H.

2007-03-01

326

Reducing mode circulating fluid bed combustion  

DOEpatents

A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

Lin, Yung-Yi (Katy, TX); Sadhukhan, Pasupati (Katy, TX); Fraley, Lowell D. (Sugarland, TX); Hsiao, Keh-Hsien (Houston, TX)

1986-01-01

327

Advanced Combustion Systems for Next Generation Gas Turbines  

SciTech Connect

Next generation turbine power plants will require high efficiency gas turbines with higher pressure ratios and turbine inlet temperatures than currently available. These increases in gas turbine cycle conditions will tend to increase NOx emissions. As the desire for higher efficiency drives pressure ratios and turbine inlet temperatures ever higher, gas turbines equipped with both lean premixed combustors and selective catalytic reduction after treatment eventually will be unable to meet the new emission goals of sub-3 ppm NOx. New gas turbine combustors are needed with lower emissions than the current state-of-the-art lean premixed combustors. In this program an advanced combustion system for the next generation of gas turbines is being developed with the goal of reducing combustor NOx emissions by 50% below the state-of-the-art. Dry Low NOx (DLN) technology is the current leader in NOx emission technology, guaranteeing 9 ppm NOx emissions for heavy duty F class gas turbines. This development program is directed at exploring advanced concepts which hold promise for meeting the low emissions targets. The trapped vortex combustor is an advanced concept in combustor design. It has been studied widely for aircraft engine applications because it has demonstrated the ability to maintain a stable flame over a wide range of fuel flow rates. Additionally, it has shown significantly lower NOx emission than a typical aircraft engine combustor and with low CO at the same time. The rapid CO burnout and low NOx production of this combustor made it a strong candidate for investigation. Incremental improvements to the DLN technology have not brought the dramatic improvements that are targeted in this program. A revolutionary combustor design is being explored because it captures many of the critical features needed to significantly reduce emissions. Experimental measurements of the combustor performance at atmospheric conditions were completed in the first phase of the program. Emissions measurements were obtained over a variety of operating conditions. A kinetics model is formulated to describe the emissions performance. The model is a tool for determining the conditions for low emission performance. The flow field was also modeled using CFD. A first prototype was developed for low emission performance on natural gas. The design utilized the tools anchored to the atmospheric prototype performance. The 1/6 scale combustor was designed for low emission performance in GE's FA+e gas turbine. A second prototype was developed to evaluate changes in the design approach. The prototype was developed at a 1/10 scale for low emission performance in GE's FA+e gas turbine. The performance of the first two prototypes gave a strong indication of the best design approach. Review of the emission results led to the development of a 3rd prototype to further reduce the combustor emissions. The original plan to produce a scaled-up prototype was pushed out beyond the scope of the current program. The 3rd prototype was designed at 1/10 scale and targeted further reductions in the full-speed full-load emissions.

Joel Haynes; Jonathan Janssen; Craig Russell; Marcus Huffman

2006-01-01

328

Effects of Propane/Natural Gas Blended Fuels on Gas Turbine Pollutant Emissions  

SciTech Connect

U.S. natural gas composition is expected to be more variable in the future. Liquefied natural gas (LNG) imports to the U.S. are expected to grow significantly over the next 10-15 years. Unconventional gas supplies, like coal-bed methane, are also expected to grow. As a result of these anticipated changes, the composition of fuel sources may vary significantly from existing domestic natural gas supplies. To allow the greatest use of gas supplies, end-use equipment should be able to accommodate the widest possible gas composition. For this reason, the effect of gas composition on combustion behavior is of interest. This paper will examine the effects of fuel variability on pollutant emissions for premixed gas turbine conditions. The experimental data presented in this paper have been collected from a pressurized single injector combustion test rig at the National Energy Technology Laboratory (NETL). The tests are conducted at 7.5 atm with a 589K air preheat. A propane blending facility is used to vary the Wobbe Index of the site natural gas. The results indicate that propane addition of about five (vol.) percent does not lead to a significant change in the observed NOx emissions. These results vary from data reported in the literature for some engine applications and potential reasons for these differences are discussed.

D. Straub; D. Ferguson; K. Casleton; G. Richards

2006-03-01

329

Combustion characteristics of hydrogen. Carbon monoxide based gaseous fuels  

NASA Technical Reports Server (NTRS)

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.

1981-01-01

330

Experimental results with hydrogen fueled internal combustion engines  

NASA Technical Reports Server (NTRS)

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

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

1975-01-01

331

Internal combustion engine in which compressed fuel mixture is combusted externally of the cylinders of the engine in a rotating combustion chamber  

Microsoft Academic Search

An internal combustion engine is described comprising a cylinder body having a pair of adjoining first and second cylinders, a reciprocable piston in each cylinder, first valve means for introducing a fuel mixture in the first cylinder, second valve means for discharge of exhaust gases from the second cylinder, a combustion chamber mounted adjacent the cylinder body for movement between

Staheli

1988-01-01

332

The Combination of Internal-Combustion Engine and Gas Turbine  

NASA Technical Reports Server (NTRS)

While the gas turbine by itself has been applied in particular cases for power generation and is in a state of promising development in this field, it has already met with considerable success in two cases when used as an exhaust turbine in connection with a centrifugal compressor, namely, in the supercharging of combustion engines and in the Velox process, which is of particular application for furnaces. In the present paper the most important possibilities of combining a combustion engine with a gas turbine are considered. These "combination engines " are compared with the simple gas turbine on whose state of development a brief review will first be given. The critical evaluation of the possibilities of development and fields of application of the various combustion engine systems, wherever it is not clearly expressed in the publications referred to, represents the opinion of the author. The state of development of the internal-combustion engine is in its main features generally known. It is used predominantly at the present time for the propulsion of aircraft and road vehicles and, except for certain restrictions due to war conditions, has been used to an increasing extent in ships and rail cars and in some fields applied as stationary power generators. In the Diesel engine a most economical heat engine with a useful efficiency of about 40 percent exists and in the Otto aircraft engine a heat engine of greatest power per unit weight of about 0.5 kilogram per horsepower.

Zinner, K.

1947-01-01

333

Catalytic iron oxide for lime regeneration in carbonaceous fuel combustion  

DOEpatents

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

Shen, Ming-Shing (Rocky Point, NY); Yang, Ralph T. (Middle Island, NY)

1980-01-01

334

Effects of fuel and additives on combustion chamber deposits  

SciTech Connect

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

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

1994-10-01

335

An Overview of Compressed Natural Gas as an Alternative Fuel and Malaysian Scenario  

Microsoft Academic Search

Natural gas in the form of compressed natural gas (CNG) becoming the subject of interest today, as the combustion of gasoline and diesel fuels result in the emission of noxious pollutants which threaten the very survival of life in this planet. this overview will concentrate on Malaysian scenarios of using CNG, and the trend of research to overcome the lack

Awang Idris; Rosli Abu Bakar

336

Development of the utilization of combustible gas produced in existing sanitary landfills: Investigation of effects of air inclusion  

NASA Astrophysics Data System (ADS)

The effects of nitrogen and oxygen on landfill gas operations are discussed. A combustible gas mixture composed of methane and carbon dioxide is generated in municipal solid waste landfills. A consequence of the collection of this fuel gas is the inclusion of some air in the collected product. The effects include increased collected and purification costs, reduction in the quality of the fuel gas produced, corrosion, explosion hazards, and interference with odorant systems. The scope of such effects was determined by using landfill data of a gas recovery site as a basis. Useful supplemental fuel gas may be recovered despite the inclusion of air. Recommendations are made for establishing limits for nitrogen and oxygen content and minimizing the costs associated with their presence.

1983-01-01

337

Predicting gaseous emissions from small-scale combustion of agricultural biomass fuels.  

PubMed

A prediction model of gaseous emissions (CO, CO2, NOx, SO2 and HCl) from small-scale combustion of agricultural biomass fuels was developed in order to rapidly assess their potential to be burned in accordance to current environmental threshold values. The model was established based on calculation of thermodynamic equilibrium of reactive multicomponent systems using Gibbs free energy minimization. Since this method has been widely used to estimate the composition of the syngas from wood gasification, the model was first validated by comparing its prediction results with those of similar models from the literature. The model was then used to evaluate the main gas emissions from the combustion of four dedicated energy crops (short-rotation willow, reed canary grass, switchgrass and miscanthus) previously burned in a 29-kW boiler. The prediction values revealed good agreement with the experimental results. The model was particularly effective in estimating the influence of harvest season on SO2 emissions. PMID:25543541

Fournel, S; Marcos, B; Godbout, S; Heitz, M

2015-03-01

338

Effect of temperature on reduction of CaSO oxygen carrier in chemical-looping combustion of simulated coal gas in a fluidized bed reactor  

Microsoft Academic Search

Chemical-looping combustion (CLC) is a promising combustion technology for gaseous and solid fuel with efficient use of energy and inherent separation of CO. The concept of a coal-fueled CLC system using, calcium sulfate (CaSO) as oxygen carrier is proposed in this study. Reduction tests of CaSO oxygen carrier with simulated coal gas were performed in a laboratory-scale fluidized bed reactor

Q. L. Song; R. Xiao; Z. Y. Deng; L. H. Shen; J. Xiao; M. Y. Zhang

2008-01-01

339

Effects of Steam and CO2 in the Fluidizing Gas when Using Bituminous Coal in Chemical-Looping Combustion  

NASA Astrophysics Data System (ADS)

Chemical-looping combustion (CLC) is a combustion technology where an oxygen carrier is used to transfer oxygen from the combustion air to the fuel in order to avoid direct contact between air and fuel. Thus, the CO2 is inherently separated from the flue gases with a potential for considerably lower energy penalty and cost compared to other techniques for CO2 separation. The oxygen carrier is circulated between two reactors, a fuel and an air reactor, where the flue gas from the air reactor contains oxygen depleted air and the flue gas from the fuel reactor contains mainly CO2 and H2O. The water can easily be condensed and the remaining CO2 can be transported for underground storage. Most of the prior work with CLC has focused on using natural gas and syngas as fuel and oxygen carrying material normally produced from pure chemicals. However, recent work on adapting the CLC process for solid fuels with ores and natural minerals as oxygen carrier shows promising results. This paper will present results from reactivity investigations in a laboratory fluidized-bed reactor system using previously investigated natural mineral ilmenite as oxygen carrier and a bituminous Colombian coal as fuel. Experiments were conducted at a temperature of 970C with N2, steam, and/or CO2 in the fluidizing gas. Synergy effects between steam and CO2 on fuel conversion was noted. The results show that the fuel conversion was a roughly a factor 5 faster with steam as compared to CO2 in the fluidizing gas.

Leion, H.; Lyngfelt, A.; Mattisson, T.

340

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

341

Determination of alternative fuels combustion products: Phase 1 report  

SciTech Connect

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

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

1997-09-01

342

Exhaust gas scrubber for internal combustion engines  

Microsoft Academic Search

An exhaust gas scrubber includes a closed tank partially filled with a pool of water and a core assembly within the tank. The assembly includes a vertical cylindrical mixing tube open at its opposite ends and extending above and below water level, an upwardly opening cylindrical deflector cup at the bottom of the tank with its opening concentrically spaced within

Coyle

1981-01-01

343

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

344

Implications of Low Particulate Matter Emissions on System Fuel Efficiency for High Efficiency Clean Combustion  

Microsoft Academic Search

Advanced diesel combustion regimes such as High Efficiency Clean Combustion (HECC) offer the benefits of reduced engine out NOX and particulate matter (PM) emissions. Lower PM emissions during advanced combustion reduce the demand on diesel particulate filters (DPFs) and can, thereby, reduce the fuel penalty associated with DPF regeneration. In this study, a SiC DPF was loaded and regenerated on

II Parks; James E; Vitaly Y Prikhodko

2009-01-01

345

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

Microsoft Academic Search

This article carries out studies on the stability characteristics of liquid fuel rocket engines within a relatively large range of variations. The research work was carried out centering around the speed and efficiency characteristics of combustion chambers. This article sets out the results of relevant experiments and theoretical calculations. From the angle of the combustion processes within combustion chambers, there

Li Xiaobin; Qizhi Chen; Yunqin Chen

1991-01-01

346

On the thermodynamics of waste heat recovery from internal combustion engine exhaust gas  

NASA Astrophysics Data System (ADS)

The ideal internal combustion (IC) engine (Otto Cycle) efficiency ?IC= 1-(1/r)^(?-1) is only a function of engine compression ratio r=Vmax/Vmin and exhaust gas specific heat ratio ?= cP/cV. Typically r= 8, ?= 1.4, and ?IC= 56%. Unlike the Carnot Cycle where ?Carnot= 1-(TC/TH) for a heat engine operating between hot and cold heat reservoirs at TH and TC, respectively, ?IC is not a function of the exhaust gas temperature. Instead, the exhaust gas temperature depends only on the intake gas temperature (ambient), r, ?, cV, and the combustion energy. The ejected exhaust gas heat is thermally decoupled from the IC engine and conveyed via the exhaust system (manifold, pipe, muffler, etc.) to ambient, and the exhaust system is simply a heat engine that does no useful work. The maximum fraction of fuel energy that can be extracted from the exhaust gas stream as useful work is (1-?IC) x?Carnot= 32% for TH= 850 K (exhaust) and TC= 370 K (coolant). This waste heat can be recovered using a heat engine such as a thermoelectric generator (TEG) with ?TEG0 in the exhaust system. A combined IC engine and TEG system can generate net useful work from the exhaust gas waste heat with efficiency ?WH= (1-?IC) x?Carnot x?TEG, and this will increase the overall fuel efficiency of the total system. Recent improvements in TEGs yield ?TEG values approaching 15% giving a potential total waste heat conversion efficiency of ?WH= 4.6%, which translates into a fuel economy improvement approaching 5%.

Meisner, G. P.

2013-03-01

347

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

348

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

E-print Network

The recovery of waste energy in furnace exhaust gases is gaining in importance as fuel costs continue to escalate. Installation of a recuperator in the furnace exhaust stream to preheat the combustion air can result in considerable savings in fuel...

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

1980-01-01

349

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 FeCr 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 700C.

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

350

Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor  

DOEpatents

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

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

2014-03-04

351

Combustion Stability Analyses for J-2X Gas Generator Development  

NASA Technical Reports Server (NTRS)

The National Aeronautics and Space Administration (NASA) is developing a liquid oxygen/liquid hydrogen rocket engine for upper stage and trans-lunar applications of the Ares vehicles for the Constellation program. This engine, designated the J-2X, is a higher pressure, higher thrust variant of the Apollo-era J-2 engine. Development was contracted to Pratt & Whitney Rocketdyne in 2006. Over the past several years, development of the gas generator for the J-2X engine has progressed through a variety of workhorse injector, chamber, and feed system configurations. Several of these configurations have resulted in injection-coupled combustion instability of the gas generator assembly at the first longitudinal mode of the combustion chamber. In this paper, the longitudinal mode combustion instabilities observed on the workhorse test stand are discussed in detail. Aspects of this combustion instability have been modeled at the NASA Marshall Space Flight Center with several codes, including the Rocket Combustor Interaction Design and Analysis (ROCCID) code and a new lumped-parameter MatLab model. To accurately predict the instability characteristics of all the chamber and injector geometries and test conditions, several features of the submodels in the ROCCID suite of calculations required modification. Finite-element analyses were conducted of several complicated combustion chamber geometries to determine how to model and anchor the chamber response in ROCCID. A large suite of sensitivity calculations were conducted to determine how to model and anchor the injector response in ROCCID. These modifications and their ramification for future stability analyses of this type are discussed in detail. The lumped-parameter MatLab model of the gas generator assembly was created as an alternative calculation to the ROCCID methodology. This paper also describes this model and the stability calculations.

Hulka, J. R.; Protz, C. S.; Casiano, M. J.; Kenny, R. J.

2010-01-01

352

The Effect of Fuel Types on Porous Alumina Produced via Soft Combustion Reaction for Implant Applications  

Microsoft Academic Search

This article describes the effects of fuel types on the porous structure of alumina produced using a soft combustion reaction.\\u000a There are several combustion parameters that could affect the porous structure of the alumina produced such as fuel-to-oxidizer\\u000a ratios, ignition temperature, and type of fuels. In this study, the effect of fuel types on alumina properties was studied.\\u000a Citric acid,

Radin Shafinaz Jamil; Khairunisak Abdul Razak; Nurfateen Fakhariah Ahmad; Hasmaliza Mohamad

353

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

Microsoft Academic Search

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

Henrik Leion; Tobias Mattisson; Anders Lyngfelt

2007-01-01

354

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

355

A kinetic-empirical model for particle size distribution evolution during pulverised fuel combustion  

Microsoft Academic Search

Particle size is an essential parameter in pulverised fuel (PF) combustion as many of the problems or further areas of development in these systems are strongly influenced by the fuel and ash size distribution. This is particularly true for dynamic processes like pollutant formation, corrosion, erosion, slagging and fouling and the related decrease of the combustion and boiler efficiency. The

Kalpit V. Shah; Mariusz K. Cieplik; Christine I. Betrand; Willem L. van de Kamp; Hari B. Vuthaluru

2010-01-01

356

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...

357

Method of treating exhaust gases from a methanol fueled internal combustion engine  

Microsoft Academic Search

A method of oxidizing that portion of a methanol fuel which has not been burned in an internal combustion engine is disclosed. Briefly, the method includes the following steps. A methanol fuel is burned in an internal combustion engine thereby to produce exhaust gases which contain unburned methanol. The exhaust gases containing the unburned methanol are passed over a catalyst

Yao

1981-01-01

358

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...

359

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

DOEpatents

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

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

1996-07-30

360

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

PubMed Central

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

Bnger, Jrgen; Krahl, Jrgen; Schrder, Olaf; Schmidt, Lasse; Westphal, Gtz A.

2012-01-01

361

CFD Simulation of High Temperature Air Combustion of Coal Gas at Different Air Straddle Angle  

Microsoft Academic Search

Numerical simulation was carried out on the High Temperature Air Combustion of coal gas in an industrial furnace with a multi-jet burner. A Beta-function PDF (Probability Density Function) combustion model was selected to simulate the gas combustion combined with the standard k-? turbulent model. The radiation was simulated by a Discrete Ordinates method. Thermal NOx model was used to calculate

Yaxin Su; Bingtao Zhao

2010-01-01

362

Soot filter in the exhaust gas flow of air-compressing internal combustion engines  

Microsoft Academic Search

A soot filter adapted to be arranged in an exhaust gas stream of air-compressing internal combustion engines is disclosed. The soot filter includes a cylindrical filter housing arranged in proximity of the exhaust gas stream of the internal combustion engine with inlet pipe connecting studs from outlet side of the internal combustion engine being connected to the cylindrical filter housing.

J. Abthoff; R. Gabler; H. Schuster

1980-01-01

363

Determination of the conversion degree of fuel bounded nitrogen compounds at the combustion of liquid fuels  

SciTech Connect

The NO-concentration in the fluegas of furnaces for liquid fuels is the sum of the thermal, prompt and fuel NO-formation. Most measures to reduce NO-emissions aim mainly on the decrease of the maximum temperature and therefore on the thermal NO-formation. Recently the fuel NO-formation has become more relevant due to the fact that for modern LowNOx combustion concepts 30 to 60% of the NO-emission result from the conversion of fuel-bounded nitrogen to NO. The reduction of the concentration of fuel-bounded nitrogen in fuels causes a high energy demand during the refining process and has not been realized yet because of economic items. Due to this reason this investigation provides fundamentals of the conversion degree of fuel-bounded nitrogen in technical flames. These fundamentals are useful to design new burner heads which can reduce the NO-emission due to the fuel NO-formation. Additionally the suitability of model fuels for a standardized judgment of the emissions in acceptance tests and for the mathematical modeling of the fuel NO-formation is discussed. In literature there are only a few results for conversion degrees of fuel-bounded nitrogen compounds. As well there is no satisfying analyzing technique for the determination of specific nitrogen compounds in liquid fuels. Therefore relevant material data for nitrous hydrocarbons which are in the boiling range of liquid fuels has been summarized. Additionally nitrogen compounds in liquid fuels were determined with a new analyzing method developed by Severin and David. Results will be presented which show the influence of the air ratio, the mass fraction of nitrogen, the basic fuel used and chosen nitrogen compound on the conversion degree in technical diffusion and premixed flames.

Lucka, K.; Koehne, H.

1998-07-01

364

Transient and translating gas jet modeling for pressure gain combustion applications  

NASA Astrophysics Data System (ADS)

Major mechanisms governing the mixing process of a gas injected into a long confined chamber is analyzed when there's a relative motion between the two. Such applications arise in a wave rotor combustor (WRCVC) where the moving combustion chambers receive gas from stationary injectors for fueling and ignition. Counter rotating vortices govern the mixing process in such problems, which moves across the channel enhancing mixing. The actions of vortices were seen to localize the injected gas in the vicinity of the injector end wall which can prove advantages during fueling to make a rich mixture near the ignition source and during hot gas injection for ignition to minimize the drop of temperature. The vortex structures can alter the exit conditions of the injector due to its strong near field interactions. The confinement is also important in which it suppresses the development and motion of such vortices and hence affect mixing. The thesis discusses several important features in a WRCVC. Namely, the effect of a combustion channel being opened to the preceding exit port prior to its opening to the gas injectors, on mixing of injected gas with channel gases. This prior opening was seen to deposit vorticity on the channel wall which gets convected along them. This convecting vorticity resulted in enhanced jet penetration. The effect of combustible mixture non-uniformity on ignition success of a WRCVC was also analyzed using 2D and 1D computations. The predictions are validated against measured data from a WRCVC test rig. Ignition locations and combustion pressures were successfully predicted. Limited 3D computations of the hot gas jet mixing with the channel gases were carried out and measure temperature data from the WRCVC test rig was used to verify the axial penetration predictions of the jet. A methodology is proposed to quantify the level of mixing and ignition success by comparing the amount of injected gas inside the channel which is above a certain threshold temperature and mass fraction limits, to the total amount of injected mass trapped inside it at that particular time. Conclusions were made on the level of mixing and the 'ignitability' of the mixture by looking at the time variation of these defined quantities.

Wijeyakulasuriya, Sameera Devsritha

365

FUEL CELL ENERGY RECOVERY FROM LANDFILL GAS  

EPA Science Inventory

International Fuel Cells Corporation is conducting a US Environmental Protection Agency (EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this application b...

366

Correlation of knocking characteristics of fuels in an engine having a hemispherical combustion chamber  

NASA Technical Reports Server (NTRS)

Data are presented to show the effects of inlet-air pressure, inlet-air temperature, and compression ratio on the maximum permissible performance obtained with having a hemispherical-dome combustion chamber. The five aircraft-engine fuels used have octane numbers varying from 90 to 100 plus 2 ml of tetraethyl lead per gallon. The data were obtained on a 5 1/4-inch by 4 3/4-inch liquid-cooled engine operating at 2,500 r.p.m. The compression ratio was varied from 6.0 to 8.9. The inlet-air temperature was varied from 110 to 310 F. For each set of conditions, the inlet-air pressure was increased until audible knock occurred and then reduced 2 inches of mercury before data were recorded. The results for each fuel can be correlated by plotting the calculated end-gas density factor against the calculated end-gas temperature. Measurements of spark-plugs, cutting off the switch to one spark plug lowered the electrode temperature of that plug from a value of 1,365 F to a value of 957 F. The results indicate that the surface temperatures of combustion-chamber areas which become new sources of ignition markedly increase after ignition.

Rothrock, A M; Biermann, Arnold E

1940-01-01

367

Explosively Driven Combustion of Shock-Dispersed Fuels  

NASA Astrophysics Data System (ADS)

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

Neuwald, Peter

2005-07-01

368

Fluidized bed combustion of pelletized biomass and waste-derived fuels  

Microsoft Academic Search

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

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

2008-01-01

369

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

Microsoft Academic Search

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

Allister Hickson; Al Phillips; Gene Morales

2007-01-01

370

Measurement of temperature, fuel concentration and equivalence ratio fields using tracer LIF in IC engine combustion  

NASA Astrophysics Data System (ADS)

A technique based on planar laser-induced fluorescence of 3-pentanone, for measurements of absolute concentration, temperature and fuel/air equivalence ratios in turbulent, high-pressure combustion systems such as an internal combustion engine is presented. Quasi-simultaneous excitation with 248 nm and 308 nm of 3-pentanone that is used as a fluorescence tracer doped to iso-octane, yields pairs of strongly temperature-dependent fluorescence images. Previous investigations have resulted in information on temperature and pressure dependence of absorption cross-sections and fluorescence quantum yields. Using these data the ratio of corresponding fluorescence images can be converted to temperature images. Instantaneous temperature distribution fields in the compression stroke and in the unburned end-gas of an SI engine were measured. The temperature fields obtained from the two-line technique are used to correct the original tracer-LIF images in order to evaluate quantitative fuel distributions in terms of number densities and fuel/air equivalence ratio.

Einecke, S.; Schulz, C.; Sick, V.

2000-11-01

371

Fuel-air mixing apparatus for reducing gas turbine combustor exhaust emissions  

NASA Technical Reports Server (NTRS)

A fuel-air mixer for use in a combustion chamber of a gas turbine engine is provided. The fuel air mixing apparatus comprises an annular fuel injector having a plurality of discrete plain jet orifices, a first swirler wherein the first swirler is located upstream from the fuel injector and a second swirler wherein the second swirler is located downstream from the fuel injector. The plurality of discrete plain jet orifices are situated between the highly swirling airstreams generated by the two radial swirlers. The distributed injection of the fuel between two highly swirling airstreams results in rapid and effective mixing to the desired fuel-air ratio and prevents the formation of local hot spots in the combustor primary zone. A combustor and a gas turbine engine comprising the fuel-air mixer of the present invention are also provided as well as a method using the fuel-air mixer of the present invention.

Zupanc, Frank J. (Inventor); Yankowich, Paul R. (Inventor)

2006-01-01

372

Alternative fuels and chemicals from synthesis gas  

SciTech Connect

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

Unknown

1998-08-01

373

ALTERNATIVE FUELS AND CHEMICALS FROM SYNTHESIS GAS  

SciTech Connect

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

Unknown

1999-01-01

374

Alternative Fuels and Chemicals From Synthesis Gas  

SciTech Connect

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

none

1998-07-01

375

ALTERNATIVE FUELS AND CHEMICALS FROM SYNTHESIS GAS  

SciTech Connect

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

Unknown

1998-01-01

376

Premixed Gas Combustion: An Excitable System  

NASA Technical Reports Server (NTRS)

Rotating spiral and target patterns have been observed experimentally on freely-propagating premixed gas flames in large diameter tubes at normal gravity (1-g). These modes of propagation occur in near-limit mixtures which have a Lewis number (Le, defined as the ratio of the thermal diffusivity of the cold mixture to the mass diffusivity of the scarce component into the mixture) sufficiently greater than one. However, at 1-g, buoyant flows strongly distort the flame curvature, hydrodynamics (thus stretch) and convective transport of species and heat. In turn, these alter the critical Le required for onset of instability. To isolate and better understand the mechanisms which drive the observed patterns and their dynamics, 1-g and microgravity (micro-g) experiments are being conducted to determine: (1) the structure and dynamics of the patterns, (2) a map of the critical Le and heat loss for their occurrence, (3) the relative significance of the chemical kinetics, and (4) the effect of curvature (local wave and global flame front) on wave propagation. With this in hand, we will be better prepared to discuss an additional mode, a state of 'chemical turbulence,' which seems to be the ultimate fate of many of these near-limit flames prior to extinction.

Pearlman, Howard

1997-01-01

377

New Developments in Closed Loop Combustion Control Using Flue Gas Analysis  

E-print Network

New developments in closed loop combustion control are causing radical changes in the way combustion control systems are implemented. The recent availability of in line flue gas analyzers and microprocessor technology are teaming up to produce...

Nelson, R. L.

1981-01-01

378

Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly report, April--June 1995  

SciTech Connect

This quarterly technical progress report summarizes the work completed during the first quarter, April 1 through June 30, 1995. The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasificafion and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the original Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/pressurized circulating fluidized bed gas source; hot gas cleanup units to mate to all gas streams; combustion gas turbine; and fuel cell and associated gas treatment. The major emphasis during this reporting period was continuing the detailed design of the facility towards completion and integrating the particulate control devices (PCDS) into the structural and process designs. Substantial progress in construction activities was achieved during the quarter. Delivery and construction of the process structural steel continued at a good pace during the quarter.

NONE

1995-08-01

379

A new comprehensive reaction mechanism for combustion of hydrocarbon fuels  

SciTech Connect

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

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

1993-12-03

380

Fluidized bed combustion of high-volatile solid fuels: An assessment of char attrition and volatile matter segregation  

SciTech Connect

A simple lumped-parameter model of a bubbling fluidized bed combustor fueled with high-volatile solid fuels is presented. The combustor is divided into three sections: the dense bed, the splashing region and the freeboard. Material balances on fixed carbon, volatile matter and oxygen are set up, taking into account fuel particle fragmentation and attrition, volatile matter segregation as well as postcombustion of both carbon fines and volatiles escaping the bed. A basic assumption of the model is that the combustion pathway that foes from the raw fuel to the combustion products proceeds via the formation of three phases: volatile matter, relatively large non-elutriable char particles and fine char particles of elutriable size. The study is complemented by a simplified thermal balance on the splashing zone taking into account volatiles and elutriated fines postcombustion and radiative and convective heat fluxes to the bed and the freeboard. Results from calculations with either low- or high-volatile solid fuels indicate that low-volatile bituminous coal combustion takes place essentially in the bed mostly via coarse char particles combustion, while high-volatile biomass fuel combustion occurs to comparable extents both in the bed and in the splashing region of the combustor. Depending on the extent of volatile matter segregation with respect to the bed, a significant fraction of the heat is released into the splashing region of the combustor and this results into an increase of temperature in this region. Extensive bed solids recirculation associated to bubble bursting/solids ejection at the bed surface together with effective gas-solids heat transfer promotes thermal feedback from this region to the bed of as much as 90% of the heat release by volatile matter and elutriated fines afterburning.

Chirone, R.; Marzocchella, A.; Salatino, P.; Scala, F.

1999-07-01

381

Effect of laser pulse energy on the laser ignition of compressed natural gas fueled engine  

NASA Astrophysics Data System (ADS)

Laser pulses of few a nanoseconds' duration are focused by an appropriate converging lens system, leading to breakdown of the medium (combustible gases), resulting in the formation of intense plasma. Plasma thus induced can be used to initiate the combustion of combustible air-fuel mixtures in a spark ignition engine provided the energy of the plasma spark is high enough. Laser ignition has several advantages over the conventional spark ignition system, especially in case of lean air-fuel mixture. In this study, laser ignition of compressed natural gas was investigated in a constant volume combustion chamber (CVCC) as well as in a single-cylinder engine. Flame kernel visualizations for different pulse energy of natural gas-air mixtures were carried out in the CVCC. The images of the development of early flame kernel stages and its growth with time were recorded by shadowgraphy technique. The effect of laser pulse energy on the engine combustion, performance, and emissions was investigated using different air-fuel mixtures. Increased peak cylinder pressure, higher rate of heat release, faster combustion, and increased combustion stability were observed for higher laser pulse energies. The effect of laser pulse energy on the engine-out emissions was also investigated in this study.

Srivastava, Dhananjay Kumar; Wintner, Ernst; Agarwal, Avinash Kumar

2014-05-01

382

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

PubMed

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

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

2015-04-01

383

PHYSICAL REVIEW E 90, 022139 (2014) Enhanced efficiency of internal combustion engines by employing spinning gas  

E-print Network

PHYSICAL REVIEW E 90, 022139 (2014) Enhanced efficiency of internal combustion engines by employing; published 28 August 2014) The efficiency of the internal combustion engine might be enhanced by employing Optimizing the internal combustion engine to achieve the highest possible fuel efficiency can be approached

384

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

385

Gas improves hog-fuel boiler performance  

SciTech Connect

One of the boilers at the Harmac Pulp Division of MacMillan Bloedel (MMB) in Nanaimo, British Columbia had a history of somewhat unstable combustion. It was subject to secondary combustion puffs caused by the delayed ignition of combustible gases generated at the grate level. The gases wouldn't ignite until they flowed upward about 15 to 20 feet in the furnace and reached the vicinity of the oil burner. Once they ignited, they produced a large, heavy furnace pressurization or puff. What MMB needed to eliminate the puffs and stabilize operations was an ignition source closer to the grate. That way, the gases would ignite sooner and at a point at which the air supply was adequate. With the help of Inproheat, the Coen Company of Burlingame, CA, the Coen Company of Canada (CBC), and natural gas, MMB was able to achieve its goal. The paper describes the boiler conversion and its performance with natural gas cofiring.

Not Available

1994-03-01

386

Functionalized graphene sheet colloids for enhanced fuel/propellant combustion.  

PubMed

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

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

2009-12-22

387

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

388

Performance/combustion characteristics of six Canadian alternative fuels tested in a bombardier medium speed diesel  

SciTech Connect

Six experimental fuels representative of Canadian future fuel options were tested against a reference fuel in a bombardier 12 cylinder, 4 stroke, 3000 hp, medium speed diesel. The reference fuel was a straight run ASTM number2-d. Each fuel was analyzed for physical and chemical properties. The engine was tested under a marine application propeller law load curve at 8 different engine speeds. Correlations between fuel properties and engine performance/combustion behaviour indicated that the longest ignition delays were observed for fuels with the lowest cetane numbers. Rates of combustion pressure rise increased proportionately with decreased cetane numbers and increased levels of aromatic components. Increases in peak combustion pressures and rates of pressure rise at low engine speeds are not expected to pose durability problems with medium speed engines operating at or near rated speed and load for the fuels tested.

Grimsey, R.G.; Stoneman, R.T.; Webster, G.D.; Chan, D.Y.

1985-01-01

389

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

390

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

SciTech Connect

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

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

2007-08-15

391

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

392

Causes of Combustion Instabilities with Passive and Active Methods of Control for practical application to Gas Turbine Engines  

NASA Astrophysics Data System (ADS)

Combustion at high pressure in applications such as rocket engines and gas turbine engines commonly experience destructive combustion instabilities. These instabilities results from interactions between combustion heat release, fluid mechanics and acoustics. This research explores the significant affect of unstable fluid mechanics processes in augmenting unstable periodic combustion heat release. The frequency of the unstable heat release may shift to match one of the combustors natural acoustic frequencies which then can result in significant energy exchange from chemical to acoustic energy resulting in thermoacoustic instability. The mechanisms of the fluid mechanics in coupling combustion to acoustics are very broad with many varying mechanisms explained in detail in the first chapter. Significant effort is made in understanding these mechanisms in this research in order to find commonalities, useful for mitigating multiple instability mechanisms. The complexity of combustion instabilities makes mitigation of combustion instabilities very difficult as few mitigation methods have historically proven to be very effective for broad ranges of combustion instabilities. This research identifies turbulence intensity near the forward stagnation point and movement of the forward stagnation point as a common link in what would otherwise appear to be very different instabilities. The most common method of stabilization of both premixed and diffusion flame combustion is through the introduction of swirl. Reverse flow along the centerline is introduced to transport heat and chemically active combustion products back upstream to sustain combustion. This research develops methods to suppress the movement of the forward stagnation point without suppressing the development of the vortex breakdown process which is critical to the transport of heat and reactive species necessary for flame stabilization. These methods are useful in suppressing the local turbulence at the forward stagnation point, limiting dissipation of heat and reactive species significantly improving stability. Combustion hardware is developed and tested to demonstrate the stability principles developed as part of this research. In order to more completely understand combustion instability a very unique method of combustion was researched where there are no discrete points of combustion initiation such as the forward stagnation point typical in many combustion systems including swirl and jet wake stabilized combustion. This class of combustion which has empirical evidence of great stability and efficient combustion with low CO, NOx and UHC emissions is described as high oxidization temperature distributed combustion. This mechanism of combustion is shown to be stable largely because there are no stagnations points susceptible to fluid mechanic perturbations. The final topic of research is active combustion control by fuel modulation. This may be the only practical method of controlling most instabilities with a single technique. As there are many papers reporting active combustion control algorithms this research focused on the complexities of the physics of fuel modulation at frequencies up to 1000 Hz with proportionally controlled flow amplitude. This research into the physics of high speed fluid movement, oscillation mechanical mechanisms and electromagnetics are demonstrated by development and testing of a High Speed Latching Oscillator Valve.

Cornwell, Michael D.

393

Question & Answers Natural Gas Fueling Infrastructure Solicitation  

E-print Network

to be renewable to get the 60% award? (Answer) A minimum of 30% of compressed natural gas or liquefied naturalQuestion & Answers Natural Gas Fueling Infrastructure Solicitation PON12605 1. If you of the Solicitation which defines renewable natural gas. 3. Do the projects have to be for new stations

394

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

395

Emission characteristics and combustion instabilities in an oxy-fuel swirl-stabilized combustor  

Microsoft Academic Search

This paper presents an experimental study on the emission characteristics and combustion instabilities of oxy-fuel combustions\\u000a in a swirl-stabilized combustor. Different oxygen concentrations (X\\u000a oxy=25%?45%, where X\\u000a oxy is oxygen concentration by volume), equivalence ratios (?=0.75?1.15) and combustion powers (CP=1.08?2.02 kW) were investigated in the oxy-fuel (CH4\\/CO2\\/O2) combustions, and reference cases (X\\u000a oxy=25%?35%, CH4\\/N2\\/O2 flames) were covered. The results show

Guo-neng Li; Hao Zhou; Ke-fa Cen

2008-01-01

396

Numerical simulation of air and oxy-fuel combustion of single coal particles using the reactive implicit continuous-fluid Eulerian (RICE) method  

NASA Astrophysics Data System (ADS)

The paper presents the mathematical model of air and oxy-fuel combustion of single coal particles. The combustion process has been treated as a spherically-symmetric one. The 1-dimensional time-dependent conservation equations governing the process have been numerically solved using the RICE method. The presence of a coal particle, which was treated as a discrete Lagrange particle, has modified the boundary conditions at the gas-solid interface. Numerical results show good agreement with the experimental results.

Lewtak, Robert

2013-10-01

397

Nitrogen chemistry during burnout in fuel-staged combustion  

SciTech Connect

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

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

1996-11-01

398

A Review of Materials for Gas Turbines Firing Syngas Fuels  

SciTech Connect

Following the extensive development work carried out in the 1990's, gas turbine combined-cycle (GTCC) systems burning natural gas represent a reliable and efficient power generation technology widely used in many parts of the world. A critical factor was that, in order to operate at the high turbine entry temperatures required for high efficiency operation, aero-engine technology, i.e., single-crystal blades, thermal barrier coatings, and sophisticated cooling techniques had to be rapidly scaled up and introduced into these large gas turbines. The problems with reliability that resulted have been largely overcome, so that the high-efficiency GTCC power generation system is now a mature technology, capable of achieving high levels of availability. The high price of natural gas and concern about emission of greenhouse gases has focused attention on the desirability of replacing natural gas with gas derived from coal (syngas) in these gas turbine systems, since typical systems analyses indicate that IGCC plants have some potential to fulfil the requirement for a zero-emissions power generation system. In this review, the current status of materials for the critical hot gas path parts in large gas turbines is briefly considered in the context of the need to burn syngas. A critical factor is that the syngas is a low-Btu fuel, and the higher mass flow compared to natural gas will tend to increase the power output of the engine. However, modifications to the turbine and to the combustion system also will be necessary. It will be shown that many of the materials used in current engines will also be applicable to units burning syngas but, since the combustion environment will contain a greater level of impurities (especially sulfur, water vapor, and particulates), the durability of some components may be prejudiced. Consequently, some effort will be needed to develop improved coatings to resist attack by sulfur-containing compounds, and also erosion.

Gibbons, Thomas [ORNL; Wright, Ian G [ORNL

2009-05-01

399

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

400

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

401

The development of an electrochemical technique for in situ calibrating of combustible gas detectors  

NASA Technical Reports Server (NTRS)

A program to determine the feasibility of performing in situ calibration of combustible gas detectors was successfully completed. Several possible techniques for performing the in situ calibration were proposed. The approach that showed the most promise involved the use of a miniature water vapor electrolysis cell for the generation of hydrogen within the flame arrestor of a combustible gas detector to be used for the purpose of calibrating the combustible gas detectors. A preliminary breadboard of the in situ calibration hardware was designed, fabricated and assembled. The breadboard equipment consisted of a commercially available combustible gas detector, modified to incorporate a water vapor electrolysis cell, and the instrumentation required for controlling the water vapor electrolysis and controlling and calibrating the combustible gas detector. The results showed that operation of the water vapor electrolysis at a given current density for a specific time period resulted in the attainment of a hydrogen concentration plateau within the flame arrestor of the combustible gas detector.

Shumar, J. W.; Lantz, J. B.; Schubert, F. H.

1976-01-01

402

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

PubMed

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

Golovitchev, Valeri I; Yang, Junfeng

2009-01-01

403

High-bandwidth Modulation of H2/Syngas Fuel to Control Combustion Dynamics in Micro-Mixing Lean Premix Systems  

SciTech Connect

The goal of this program was to develop and demonstrate fuel injection technologies that will facilitate the development of cost-effective turbine engines for Integrated Gasification Combined Cycle (IGCC) power plants, while improving efficiency and reducing emissions. The program involved developing a next-generation multi-point injector with enhanced stability performance for lean premix turbine systems that burn hydrogen (H2) or synthesis gas (syngas) fuels. A previously developed injector that demonstrated superior emissions performance was improved to enhance static flame stability through zone staging and pilot sheltering. In addition, piezo valve technology was implemented to investigate the potential for enhanced dynamic stability through high-bandwidth modulation of the fuel supply. Prototype injector and valve hardware were tested in an atmospheric combustion facility. The program was successful in meeting its objectives. Specifically, the following was accomplished: Demonstrated improvement of lean operability of the Parker multi-point injector through staging of fuel flow and primary zone sheltering; Developed a piezo valve capable of proportional and high-bandwidth modulation of gaseous fuel flow at frequencies as high as 500 Hz; The valve was shown to be capable of effecting changes to flame dynamics, heat release, and acoustic signature of an atmospheric combustor. The latter achievement indicates the viability of the Parker piezo valve technology for use in future adaptively controlled systems for the mitigation of combustion instabilities, particularly for attenuating combustion dynamics under ultra-lean conditions.

Jeff Melzak; Tim Lieuwen; Adel Mansour

2012-01-31

404

Tungsten carbide synthesized by low-temperature combustion as gas diffusion electrode catalyst  

E-print Network

Tungsten carbide synthesized by low-temperature combustion as gas diffusion electrode catalyst Ping June 2014 Keywords: Low-temperature combustion syn- thesis Tungsten carbide Electrocatalyst Gas diffusion electrode a b s t r a c t Tungsten carbide powder, which is used as the catalyst for a gas

Volinsky, Alex A.

405

Investigation of Colorless Distributed Combustion (CDC) with Swirl for Gas Turbine Application  

NASA Astrophysics Data System (ADS)

Colorless Distributed Combustion (CDC) with swirl is investigated for gas turbine engine applications due to its benefits for ultra-low pollutants emission, improved pattern factor and thermal field uniformity, low noise emission, and stable combustion with the alleviation of combustion instabilities. Adequate and fast mixing between the injected air and internally recirculated hot reactive gases to form hot and diluted oxidant is critical for CDC, followed by rapid mixing with the fuel. This results in distributed reaction zone instead of a concentrated thin flame front as observed in conventional diffusion flames, leading to avoidance of hot spot regions and providing reduced NOx and CO emissions. The focus of this dissertation is to develop and demonstrate CDC in a cylindrical combustor for application to stationary gas turbine combustors. The dissertation examines the sequential development of ultra-low emission colorless distributed combustor operating at a nominal thermal intensity of 36MW/m3-atm. Initially, the role of swirl is evaluated through comparing the performance of swirling and non-swirling configurations with focus on pollutants emission, stability, and isothermal flowfield through particle image velocimetry. Different fuel injection locations have also been examined, and based on performance a swirling configuration have been down selected for further investigations demonstrating emissions as low as 1 PPM of NO with a 40% reduction compared to non-swirling configuration. Further investigations were performed to outline the impact of inlet air temperature and combustor pressure on reaction distribution and combustor performance. Next, Fuel flexibility has been examined with view to develop CDC combustors that can handle different gaseous and liquid fuels, both traditional and renewable. These fuels included diluted methane, hydrogen enriched methane, propane, ethanol, kerosene, JP-8, Hydrogenated Renewable Jet fuel, and novel biofuel. Swirling CDC combustor demonstrated emissions below 7.5 PPM of NO regardless of the fuel used, with emissions below 40PPM of CO for liquid fuels and 10 PPM for gaseous fuels. Further enhancement of swirling CDC combustor was sought next. Various fuel injection techniques have been examined, outlining the importance of fuel injection location with respect to air and hot reactive gases recirculation. The impact of air injection velocity on combustor performance have been examined in terms of increased recirculation (via isothermal flow field characterization using PIV) and enhanced performance with lower pollutants emission leading to 45% reduction in NO emissions with no impact on CO emissions. The impact of fuel dilution on mixing and performance has been also examined as a method to enhance mixing due to the increased fuel jet momentum. Dual air and fuel injection have been explored to outline the impact of multi injection on combustor performance for scaling up of the combustor. Planar Laser Induced Fluorescence technique was used to evaluate the reaction behavior and its distribution in the combustor through detection of activated OH radicals at different activation lines in different configurations. The different investigations performed (experimentally and numerically) have been compiled and analyzed with view to develop a "Distribution Index" that evaluated the reaction distribution in a given combustor based on certain parameters. These parameters include, but no limited to, hot reactive gases recirculation (entrainment) rate, air injection velocity, mixing between air and fuel, and operational equivalence ratio and inlet air temperature. The developed distribution index, DI, will be a valuable tool for future combustor design.

Khalil Hasan, Ahmed Essam ElDin

406

Biomass and fossil fuel conversion by pressurised fluidised bed gasification using hot gas ceramic filters as gas cleaning  

Microsoft Academic Search

Gasification of biomass and fossil fuels, hot gas cleanup using a ceramic filter and combustion of LCV product gas in a combustor were performed using a 1.5MWth test rig (pressurised bubbling fluidised bed gasifier) at Delft University and a 1050kWth system at Stuttgart University (DWSA) in the framework of experimental research on efficient, environmentally acceptable large-scale power generators based on

Wiebren de Jong; mer nal; Jans Andries; Klaus R. G Hein; Hartmut Spliethoff

2003-01-01

407

BIOMASS COMBUSTION IN GAS-TURBINE-BASED SYSTEMS  

EPA Science Inventory

The paper gives results of a comparative evaluation of a range of biomass power generation systems. he objective was to identify systems most suitable for unique properties of biomass. he characteristics of biomass fuels were reviewed, and the performance of several gas-turbine-b...

408

Using exhaust gas recirculation in internal combustion engines: a review  

Microsoft Academic Search

The aim of this work is to review the potential of exhaust gas recirculation (EGR) to reduce the exhaust emissions, particularly NOX emissions, and to delimit the application range of this technique. A detailed analysis of previous and current results of EGR effects on the emissions and performance of Diesel engines, spark ignition engines and duel fuel engines is introduced.

G. H. Abd-Alla

2002-01-01

409

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

410

Computational Fluid Dynamics Modelling of Residual Fuel Oil Combustion in the Context of Marine Diesel Engines  

Microsoft Academic Search

A simplified model is presented for vaporization and combustion of heavy residual based fuel oil in high-pressure sprays, in the context of marine diesel engines. The fuel is considered as a mix of residual base and cutter stock. The model accounts for multiple fuel components as well as limited diffusion rates and thermal decomposition rates within droplets by the use

L Goldsworthy

2006-01-01

411

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...

412

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

413

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

414

Determining size of drops in fuel mixture of internal combustion engines  

NASA Technical Reports Server (NTRS)

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

Sauter, J

1926-01-01

415

Water-gas process  

Microsoft Academic Search

This presents a method of producing gas from culm. The steps consist in igniting a body of the fuel, effecting partial combustion thereof, arresting such combustion before a substantial amount of the ash content has fused, passing steam through the partially consumed fuel to produce water gas, withdrawing most of the partially consumed fuel, and adding fresh fuel to replace

Dechant

1934-01-01

416

Method And Apparatus For Converting Hydrocarbon Fuel Into Hydrogen Gas And Carbon Dioxide  

DOEpatents

A hydrocarbon fuel reforming method is disclosed suitable for producing synthesis hydrogen gas from reactions with hydrocarbons fuels, oxygen, and steam. A first mixture of an oxygen-containing gas and a first fuel is directed into a first tube 108 to produce a first reaction reformate. A second mixture of steam and a second fuel is directed into a second tube 116 annularly disposed about the first tube 108 to produce a second reaction reformate. The first and second reaction reformates are then directed into a reforming zone 144 and subject to a catalytic reforming reaction. In another aspect of the method, a first fuel is combusted with an oxygen-containing gas in a first zone 108 to produce a reformate stream, while a second fuel under steam reforming in a second zone 116. Heat energy from the first zone 108 is transferred to the second zone 116.

Clawson, Lawrence G. (Dover, MA); Mitchell, William L. (Belmont, MA); Bentley, Jeffrey M. (Westford, MA); Thijssen, Johannes H. J. (Cambridge, MA)

2001-03-27

417

A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream  

SciTech Connect

A diffusion-kinetic model for pulverized-coal combustion and heat-and-mass transfer in a gas stream is proposed, and the results of numerical simulation of the burnout dynamics of Kansk-Achinsk coals in the pulverized state at different treatment conditions and different model parameters are presented. The mathematical model describes the dynamics of thermochemical conversion of solid organic fuels with allowance for complex physicochemical phenomena of heat-and-mass exchange between coal particles and the gaseous environment.

E.A. Boiko; S.V. Pachkovskii [Polytechnic Institute, Federal University of Siberia, Krasnoyarsk (Russian Federation)

2008-12-15

418

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

419

Diffusion combustion of a liquid fuel film on a metal substrate  

Microsoft Academic Search

Diffusion combustion of a film of a liquid fuel (n-undecane andn-butanol) deposited on the surface of a thin metal substrate is studied experimentally and theoretically. The experimental\\u000a data obtained show that the mechanism determining the heating and evaporation of the combustible liquid is the heat transfer\\u000a from the region of combustion products to the heating zone due to the high

I. G. Namyatov; S. S. Minaev; V. S. Babkin; V. A. Bunev; A. A. Korzhavin

2000-01-01

420

LANDFILL GAS PRETREATMENT FOR FUEL CELL APPLICATIONS  

EPA Science Inventory

The paper discusses the U.S. EPA's program, underway at International Fuel Cells Corporation, to demonstrate landfill methane control and the fuel cell energy recovery concept. In this program, two critical issues are being addressed: (1) a landfill gas cleanup method that would ...

421

Effects of Fuel Composition on Combustion Stability and NO X Emissions for Traditional and Alternative Jet Fuels  

NASA Astrophysics Data System (ADS)

Synthetic jet fuels are studied to help understand their viability as alternatives to traditionally derived jet fuel. Two combustion parameters -- flame stability and NOX emissions -- are used to compare these fuels through experiments and models. At its core, this is a fuels study comparing how chemical makeup and behavior relate. Six 'real', complex fuels are studied in this work -- four are synthetic from alternative sources and two are traditional from petroleum sources. Two of the synthetic fuels are derived from natural gas and coal via the Fischer Tropsch catalytic process. The other two are derived from Camelina oil and tallow via hydroprocessing. The traditional military jet fuel, JP8, is used as a baseline as it is derived from petroleum. The sixth fuel is derived from petroleum and is used to study the effects of aromatic content on the synthetic fuels. The synthetic fuels lack aromatic compounds, which are an important class of hydrocarbons necessary for fuel handling systems to function properly. Several single-component fuels are studied (through models and/or experiments) to facilitate interpretation and understanding. The flame stability study first compares all the 'real', complex fuels for blowout. A toroidal stirred reactor is used to try and isolate temperature and chemical effects. The modeling study of blowout in the toroidal reactor is the key to understanding any fuel-based differences in blowout behavior. A detailed, reacting CFD model of methane is used to understand how the reactor stabilizes the flame and how that changes as the reactor approaches blowout. A 22 species reduced form of GRI 3.0 is used to model methane chemistry. The knowledge of the radical species role is utilized to investigate the differences between a highly aliphatic fuel (surrogated by iso-octane) and a highly aromatic fuel (surrogated by toluene). A perfectly stirred reactor model is used to study the chemical kinetic pathways for these fuels near blowout. The differences in flame stabilization can be attributed to the rate at which these fuels are attacked and destroyed by radical species. The slow disintegration of the aromatic rings reduces the radical pool available for chain-initiating and chain-branching, which ultimately leads to an earlier blowout. The NOX study compares JP8, the aromatic additive, the synthetic fuels with and without an aromatic additive, and an aromatic surrogate (1,3,5-trimethylbenzene). A jet stirred reactor is used to try and isolate temperature and chemical effects. The reactor has a volume of 15.8 mL and a residence time of approximately 2.5 ms. The fuel flow rate (hence equivalence ratio) is adjusted to achieve nominally consistent temperatures of 1800, 1850, and 1900K. Small oscillations in fuel flow rate cause the data to appear in bands, which facilitated Arrhenius-type NOX-temperature correlations for direct comparison between fuels. The fuel comparisons are somewhat inconsistent, especially when the aromatic fuel is blended into the synthetic fuels. In general, the aromatic surrogate (1,3,5-trimethylbenzene) produces the most NOX, followed by JP8. The synthetic fuels (without aromatic additive) are always in the same ranking order for NOX production (HP Camelina > FT Coal > FT Natural Gas > HP Tallow). The aromatic additive ranks differently based on the temperature, which appears to indicate that some of the differences in NOX formation are due to the Zeldovich NOX formation pathway. The aromatic additive increases NOX for the HP Tallow and decreases NOX for the FT Coal. The aromatic additive causes increased NOX at low temperatures but decreases NOX at high temperatures for the HP Camelina and FT Natural Gas. A single perfectly stirred reactor model is used with several chemical kinetic mechanisms to study the effects of fuel (and fuel class) on NO X formation. The 27 unique NOX formation reactions from GRI 3.0 are added to published mechanisms for jet fuel surrogates. The investigation first looked at iso-octane and toluene and found that toluene produces more NOX beca

Vijlee, Shazib Z.

422

Hot gas cleanup test facility for gasification and pressurized combustion. Quarterly technical progress report, July 1--September 30, 1992  

SciTech Connect

The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The conceptual design of the facility was extended to include a within scope, phased expansion of the existing Hot Gas Cleanup Test Facility Cooperative Agreement to also address systems integration issues of hot particulate removal in advanced coal-based power generation systems. This expansion included the consideration of the following modules at the test facility in addition to the existing Transport Reactor gas source and Hot Gas Cleanup Units: Carbonizer/Pressurized Circulating Fluidized Bed Gas Source; hot Gas Cleanup Units to mate to all gas streams; and Combustion Gas Turbine. Fuel Cell and associated gas treatment. This expansion to the Hot Gas Cleanup Test Facility is herein referred to as the Power Systems Development Facility (PSDF).

Not Available

1992-12-31

423

NATURAL GAS FIRED POWER PLANTS WITH CO2CAPTURE - PROCESS INTEGRATION FOR HIGH FUEL-TO-ELECTRICITY CONVERSION EFFICIENCY  

Microsoft Academic Search

A concept for capturing and sequestering CO2 from a natural gas fired combined cycle power plant is presented. The present approach is to decarbonise the fuel prior to combustion by reforming natural gas, producing a hydrogen-rich fuel. The reforming process consists of an air-blown pressurised auto-thermal reformer that produces a gas containing H2, CO and a small fraction of CH4

Hanne M. Kvamsdal; Thormod Andersen

424

Hot Gas Cleanup Test Facility for gasification and pressurized combustion  

SciTech Connect

The objective of this project is to evaluate hot gas particle control technologies using coal-derived gas streams. This will entail the design, construction, installation, and use of a flexible test facility which can operate under realistic gasification and combustion conditions. The major particulate control device issues to be addressed include the integration of the particulate control devices into coal utilization systems, on-line cleaning techniques, chemical and thermal degradation of components, fatigue or structural failures, blinding, collection efficiency as a function of particle size, and scale-up of particulate control systems to commercial size. The major emphasis during this reporting period was finishing the conceptual design for the test facility and discussions on the potential expansion of the test facility. Results are discussed for the following subtasks of conceptual design: design bases; quasifier/combustor and hot stream design; balance of plant designs; and particulate collection.

Not Available

1991-01-01

425

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

NASA Technical Reports Server (NTRS)

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

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

1991-01-01

426

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

Microsoft Academic Search

High temperature air combustion (HTAC) is a promising technology for energy saving, flame stability enhancement and NOx emission reduction. In a conventional HTAC system, the combustion air is highly preheated by using the recuperative or regenerative heat exchangers. However, such a preheating process is difficult to implement for pulverized fossil fuel fired boilers. In this paper, an alternative approach is

Hai Zhang; Guangxi Yue; Junfu Lu; Zhen Jia; Jiangxiong Mao; Toshiro Fujimori; Toshiyuki Suko; Takashi Kiga

2007-01-01

427

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...

428

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...

429

New Paradigm for Simulation of Turbulent Combustion in Realistic Gas Turbine Combustors Using LES  

NASA Astrophysics Data System (ADS)

The large eddy simulation technique has been extended to the simulation of a realistic combustor of a gas turbine engine. We discuss our work on a massively parallel solver for LES of reacting and non-reacting flows on unstructured grids with arbitrary elements. A novelty of our approach is a new numerical algorithm that is discretely energy conserving on hybrid unstructured grids (Mahesh et al., 2001, Annual Research Briefs, Center for Turbulence Research) thus allowing simulations at high Reynolds numbers without the use of numerical dissipation. This methodology has been validated in both canonical flows as well as against experimental data in industrial configurations. Excellent agreement with the data has been obtained. This LES methodology has been extended to include spray modeling and the progress variable combustion model (Pierce & Moin, 2001, Report TF-80, Stanford University). Results from simulations in coaxial combustors, complex fuel injectors and the flow in an entire gas-turbine combustor will be presented.

Constantinescu, George; Mahesh, Krishnan; Apte, Souraph; Iaccarino, Gianluca; Moin, Parviz

2002-11-01

430

Design and Operation of the Synthesis Gas Generator System for Reformed Propane and Glycerin Combustion  

NASA Astrophysics Data System (ADS)

Due to an increased interest in sustainable energy, biodiesel has become much more widely used in the last several years. Glycerin, one major waste component in biodiesel production, can be converted into a hydrogen rich synthesis gas to be used in an engine generator to recover energy from the biodiesel production process. This thesis contains information detailing the production, testing, and analysis of a unique synthesis generator rig at the University of Kansas. Chapter 2 gives a complete background of all major components, as well as how they are operated. In addition to component descriptions, methods for operating the system on pure propane, reformed propane, reformed glycerin along with the methodology of data acquisition is described. This chapter will serve as a complete operating manual for future students to continue research on the project. Chapter 3 details the literature review that was completed to better understand fuel reforming of propane and glycerin. This chapter also describes the numerical model produced to estimate the species produced during reformation activities. The model was applied to propane reformation in a proof of concept and calibration test before moving to glycerin reformation and its subsequent combustion. Chapter 4 first describes the efforts to apply the numerical model to glycerin using the calibration tools from propane reformation. It then discusses catalytic material preparation and glycerin reformation tests. Gas chromatography analysis of the reformer effluent was completed to compare to theoretical values from the numerical model. Finally, combustion of reformed glycerin was completed for power generation. Tests were completed to compare emissions from syngas combustion and propane combustion.

Pickett, Derek Kyle

431

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

NASA Technical Reports Server (NTRS)

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

Frate, David T.

2004-01-01

432

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

433

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

434

Combustion of a substitution fuel made of cardboard and polyethylene: influence of the mix characteristicsexperimental approach  

Microsoft Academic Search

This article presents an experimental study of the combustion of substitution fuels elaborated from compressed mixes of cardboard and polyethylene (PE). These components are representative of two classical classes of waste materials: materials derived from wood and plastics. The combustion of these fuels has been experimentally characterized in terms of combustion rate, and quantity of PolyAromatic Hydrocarbons (PAH) pollutants emitted.

S. Salvador; M. Quintard; C. David

2004-01-01

435

Multi-zone modelling of partially premixed low-temperature combustion in pilot-ignited natural-gas engines  

SciTech Connect

Detailed results from a multi-zone phenomenological simulation of partially premixed advanced-injection low-pilot-ignited natural-gas low-temperature combustion are presented with a focus on early injection timings (the beginning of (pilot) injection (BOI)) and very small diesel quantities (2-3 per cent of total fuel energy). Combining several aspects of diesel and spark ignition engine combustion models, the closed-cycle simulation accounted for diesel autoignition, diesel spray combustion, and natural-gas combustion by premixed turbulent flame propagation. The cylinder contents were divided into an unburned zone, several pilot fuel zones (or 'packets') that modelled diesel evaporation and ignition, a flame zone for natural-gas combustion, and a burned zone. The simulation predicted the onset of ignition, cylinder pressures, and heat release rate profiles satisfactorily over a wide range of BOIs (20-60???° before top dead centre (before TDC)) but especially well at early BOIs. Strong coupling was observed between pilot spray combustion in the packets and premixed turbulent combustion in the flame zone and, therefore, the number of ignition centres (packets) profoundly affected flame combustion. The highest local peak temperatures (greater than 2000 K) were observed in the packets, while the flame zone was much cooler (about 1650 K), indicating that pilot diesel spray combustion is probably the dominant source of engine-out emissions of nitrogen oxide (NO x). Further, the 60???° before TDC BOI yielded the lowest average peak packet temperatures (about 1720 K) compared with the 20???° before TDC BOI (about 2480 K) and 40???° before TDC BOI (about 2700 K). These trends support experimental NO x trends, which showed the lowest NO x emissions for the 60???°, 20???°, and 40???° before TDC BOIs in that order. Parametric studies showed that increasing the intake charge temperature, pilot quantity, and natural-gas equivalence ratio all led to higher peak heat release rates and hotter packets but the pilot quantity and intake temperature affected the potential for NO x formation to a greater extent.

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

2010-06-29

436

Part-load performance characteristics of a lean burn catalytic combustion gas turbine system  

NASA Astrophysics Data System (ADS)

The purpose of this study is to compare the part-load performance of a lean burn catalytic combustion gas turbine (LBCCGT) system in three different control modes: varying fuel, bleeding off the fuel mixture flow after the compressor and varying rotational speed. The conversions of methane species for chemical process are considered. A 1D heterogeneous plug flow model was utilized to analyze the system performance. The actual turbomachinery components were designed and predicted performance maps were applied to system performance research. The part-load characteristics under three control strategies were numerically investigated. The main results show that: the combustor inlet temperature is a significant factor that can significantly affect the part-load characteristics of the LBCCGT system; the rotational speed control mode can provide the best performance characteristics for part-load operations; the operation range of the bleed off mode is narrower than that of the speed control mode and wider than that of the fuel only mode; with reduced power, methane does not achieve full conversion over the reactor at the fuel only control mode, which will not warrant stable operation of the turbine system; the thermal efficiency of the LBCCGT system at fuel only control strategy is higher than that at bleed off control strategy within the operation range.

Yin, Juan; Li, Ming; Zhu, Jun-qiang

2013-04-01

437

Alternative Fuels and Chemicals from Synthesis Gas  

SciTech Connect

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE?s LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.

None

1998-12-02

438

Fuel injector for use in a gas turbine engine  

SciTech Connect

A fuel injector in a combustor apparatus of a gas turbine engine. An outer wall of the injector defines an interior volume in which an intermediate wall is disposed. A first gap is formed between the outer wall and the intermediate wall. The intermediate wall defines an internal volume in which an inner wall is disposed. A second gap is formed between the intermediate wall and the inner wall. The second gap receives cooling fluid that cools the injector. The cooling fluid provides convective cooling to the intermediate wall as it flows within the second gap. The cooling fluid also flows through apertures in the intermediate wall into the first gap where it provides impingement cooling to the outer wall and provides convective cooling to the outer wall. The inner wall defines a passageway that delivers fuel into a liner downstream from a main combustion zone.

Wiebe, David J.

2012-10-09

439

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

DOEpatents

Method and apparatus for safely combusting a fuel in such manner that very low levels of NO.sub.x and CO are produced. The apparatus comprises an inlet line (12) containing a fuel and an inlet line (18) containing an oxidant. Coupled to the fuel line (12) and to the oxidant line (18) is a mixing means (11,29,33,40) for thoroughly mixing the fuel and the oxidant without combusting them. Coupled to the mixing means (11,29,33,40) is a means for injecting the mixed fuel and oxidant, in the form of a large-scale fluid dynamic structure (8), into a combustion region (2). Coupled to the combustion region (2) is a means (1,29,33) for producing a periodic flow field within the combustion region (2) to mix the fuel and the oxidant with ambient gases in order to lower the temperature of combustion. The means for producing a periodic flow field can be a pulse combustor (1), a rotating band (29), or a rotating cylinder (33) within an acoustic chamber (32) positioned upstream or downstream of the region (2) of combustion. The mixing means can be a one-way flapper valve (11); a rotating cylinder (33); a rotating band (29) having slots (31) that expose open ends (20,21) of said fuel inlet line (12) and said oxidant inlet line (18) simultaneously; or a set of coaxial fuel annuli (43) and oxidizer annuli (42,44). The means for producing a periodic flow field (1, 29, 33) may or may not be in communication with an acoustic resonance. When employed, the acoustic resonance may be upstream or downstream of the region of combustion (2).

Keller, Jay O. (3534 Brunell Dr., Oakland, CA 94602); Bramlette, T. Tazwell (2105 Canyon Lakes Dr., San Ramon, CA 94583); Barr, Pamela K. (294 Joyce St., Livermore, CA 94550)

1996-01-01

440

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

Microsoft Academic Search

A method for both combustion irreversibility and working medium availability computations in a high-speed, naturally-aspirated, four-stroke, internal combustion engine cylinder is presented. Th