- Email: [email protected]
01900 Dual fuel diesel engine
70 Engines (power generation and propulsion, electrical vehicles) This paper is concerned with the on-line determination of alkali traces in solid fuel combustion using simultaneous surface ionization (SI) and excimer laser induced fragmentation fluorescence (ELIF). Both methods measure in real-time but are complementary in that ELIF can discriminate towards gas phase alkali species, whereas SI detects alkali both in the gas phase and on aerosol particles. Measurements were made in the flue gas of a 10 MW PCFB combustor at 10 bar total pressure, whereby the measuring equipment was mounted onto the flue gas pipe downstream of the hot gas filter. The combustor was fed with a bituminous coal and operated in the temperature range 850-900°C. Results show that the general response of the measured signals to parameters such as fuel load and to bed and flue gas temperatures was very similar for the two methods and reflected variations in these parameters. Concentrations determined by ELIF ranged from 6 to 63 ppb (Na) and 1 to 54 ppb (K), depending on conditions. In contrast, concentrations obtained by the SI technique were a factor of l-10 higher than for ELIF, depending on the flue gas temperature and the total alkali (gas+particle phase) present in the flue gas. In this way it can be shown that information about the physical state of the alkali species can be obtained by direct comparison of the two methods.
03/01895 Preferential diffusion effects on the burnfng of interacting turbulent premixed hydrogen-air flames
of
Richers,
Forschungszentrum
Karlsruhe,
U.
et ul. Wissenschaftliche 2002. 6686, (i-iv), l-16.
Berichte
Various approaches to the future waste management policy in Germany are currently under discussion. One problem in this connection is the suitability of existing furnaces for the co-combustion of waste. The use of sewage sludge in power plants is practiced on a technical scale. Co-combustion in power plants is of interest because of the CO2 problem, as renewable resources can also be used for this purpose. This article documents the technical status of co-combustion in Germany and the available quantities of selected supplementary fuels. Experience accumulated in German coal fired power plants in using supplementary fuels is compiled. Future possibilities arc assessed.
03/01897
Sustainable
cofiring
of biomass
with coal
Demirbas, A. Energ?, Conversim and Managemen/, 2003, 44, (9), 14651479. Biomass is an attractive renewable fuel to supplement coal combustion in utility boilers. Coal cofiring was successful with up to a 20% biomass mix. Results of extensive applications have shown that cofiring of biomass with coal have accomplished the following: (1) increased boiler efficiency, (2) reduced fuel costs and (3) reduced emissions of NO, and fossil CO*. Every ton of biomass cotired directly reduces fossil CO2 emissions by over I ton. Woody biomass contains virtually no sulfur, so SO2 emissions are reduced m direct proportion to the coal replacement. Biomass is a regenerable biofuel. When a fossil fuel is replaced by a biofuel, there is a net reduction in COP emissions. Biomass can contain considerable alkali and alkaline earth elements and chlorine. which, when mixed with other gas components derived from coal such as sulfur compounds, promotes a different array of vapor and fine particulate deposition in coal fired boilers.
Thermogravimetric
analysis
of char combustion
He, R. et al. Combustion Science and Technology, 2002, 174, (4), l-8. Nine different char samples were tested in thermogravimetric analysers with continuously rising temperatures and a global one-step kinetic reaction model was used to describe the char combustion. A mathematical method was presented to deduce the activation energy and pre-exponential factor. The results show that this method has good convergence and is relatively easy for applications. The deduced anparent activation energies and me-exoonential factors will be used for analysing diffusion efiects within char pores in a further study.
10 ENGINES Power generation and propulsion, electrical vehicles
rate
Im, H. G. and Chen, J. H. Combustion and Flume, 2002, 131, (3) 2466 258. The upstream interaction of twin premixed hydrogen-air flames in 2-D turbulence is studied using direct numerical simulations with detailed chemistry. The primary objective is to determine the effect of flame stretch on the overall burning rate during various stages of the interaction. Preferential diffusion effects are accounted for by varying the equivalence ratio from symmetric rich-rich to lean-lean interactions. The results show that the local flame front response to turbulence is consistent with previous understanding of Iaminar premixed flames, in that rich premixed flames become intensified in regions of negative strain or curvature, while the opposite response is found for lean premixed flames. The overall burning rate history with respect to the surface density variation is found to depend on the mixture condition; the consumption rate enhancement advances (follows) the surface enhancement for the rich-rich (lean-lean) case. For the lean-lean case, a self-turbulization mechanism results in a large positive skewness in the area-weighted mean tangential strain statistics. Because of the statistical dominance of positive stretch on the flame surface, the lean-lean case results in a significantly larger burning enhancement (over a twofold increase) in addition to the surface density production, For the case of rich-rich interaction, the abundance in hydrogen species results in an instantaneous overshoot of the radical pool in the post-flame region, resulting in an additional ‘burst’ in the reactant consumption rate history, suggesting its potential impact on the pollutant formation process.
03/01898 Present status and perspectives co-combustion in German power plants
03/01898
03/01899 Condition passage of nitrogen formatton of ignition improvers
of internal-combustion engine fuels by oxides from exhaust gas for in-situ enhancers and cetane number
Degen, W. et ai. U.S. Pat. Appl. Publ. US 2002 144,456 (Cl. 44412; ClOLl/22), 10 Ott 2002, Appl. 10,107,616. An internal-combustion engine fuel is provide in-situ with ignition enhancers and cetane number improvers by passage of nitrogen oxidecontaining gases (consisting of NO, NOa, or N20) through the liquid fuel at 20-150” and atmospheric pressure. The reaction forms into compounds in the fuel hydrocarbons, which act as ignition and combustion enhancers to improve cold-start behaviour. The NO,-type compounds are isolated from the exhaust gases using a storage-type catalytic converter that stores NO, NOz, and N20.
03/01900
Dual fuel diesel engine
Kumakawa, M. et al. Jpn. Kokai Tokkyo Koho JP 2002 309.979 (Cl. F02Dl9/08), 23 Ott 2002, Appl. 2001/l 15,820. 6. (In Japanese) The engine using gas oil as main fuel and CH1-based biogas from anaerobic fermentation of organic waste as fuel, includes a gas inlet pipe connecting with a biogas-supply tube for supplying the gas mixture of air and biogas to the combustion chamber, and a turbocharger for supercharge of the gas mixture without intercooler.
03/01901 Effect of ethanol-unleaded gasoline engine performance and exhaust emission
blends
on
Al-Hasan, M. Energ.)> Conversion and Management, 2003. 44, (9). 15471561. This paper investigates the effect of using unleaded gasoline-ethanol blends on SI engine performance and exhaust emission. A four stroke, four cylinder SI engine (type TOYOTA, TERCEL-3A) was used for conducting this study. Performance tests were conducted for equivalence air-fuel ratio, fuel consumption, volumetric efficiency, brake thermal efficiency, brake power, engine torque and brake specific fuel consumption, while exhaust emissions were analysed for carbon monoxide (CO), carbon dioxide (COa) and unburned hydrocarbons (HC), using unleaded gasoline-ethanol blends with different percentages of fuel at three-fourth throttle opening position and variable engine speed ranging from 1000 to 4000 rpm. The results showed that blending unleaded gasoline with ethanol increases the brake power, torque, volumetric and brake thermal efficiencies and fuel consumption, while it decreases the brake specific fuel consumption and equivalence air-fuel ratio. The CO and HC emissions concentrations in the engine exhaust decrease, while the COa concentration increases. The 20 vol.% ethanol in fuel blend gave the best results for all measured parameters at all engine speeds.
03/01902
Formulated
Gasohol
composition
for automobiles
Song, S. and Wang, Z. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,332,227 (Cl. ClOLlIO2) 23 Jan 2002, Appl. 2,001,119,418. (In Chinese) The title composition comprises a gasoline base 65-85, MeOH 10-20, ether compound (especially MTBE) 5-15 weight%, and trace amount of corrosion inhibitor and detergent. The composition is superior in high miscibility, cold ignitability and reducing noxious emissions.
03/01903 Gas turbine combustor for biomass derived gas, a first approach towards fuel-NO, modeling and expertmentsi validation Adouane,
B. et al. Applied Fuel
and
Thermal
Energy
Engineering,
Abstracts
LCV
2002, 22. (8). 959~970.
September
2003
319
03/01895 Preferential diffusion effects on the burnfng of interacting turbulent premixed hydrogen-air flames
of
Richers,
Forschungszentrum
Karlsruhe,
U.
et ul. Wissenschaftliche 2002. 6686, (i-iv), l-16.
Berichte
Various approaches to the future waste management policy in Germany are currently under discussion. One problem in this connection is the suitability of existing furnaces for the co-combustion of waste. The use of sewage sludge in power plants is practiced on a technical scale. Co-combustion in power plants is of interest because of the CO2 problem, as renewable resources can also be used for this purpose. This article documents the technical status of co-combustion in Germany and the available quantities of selected supplementary fuels. Experience accumulated in German coal fired power plants in using supplementary fuels is compiled. Future possibilities arc assessed.
03/01897
Sustainable
cofiring
of biomass
with coal
Demirbas, A. Energ?, Conversim and Managemen/, 2003, 44, (9), 14651479. Biomass is an attractive renewable fuel to supplement coal combustion in utility boilers. Coal cofiring was successful with up to a 20% biomass mix. Results of extensive applications have shown that cofiring of biomass with coal have accomplished the following: (1) increased boiler efficiency, (2) reduced fuel costs and (3) reduced emissions of NO, and fossil CO*. Every ton of biomass cotired directly reduces fossil CO2 emissions by over I ton. Woody biomass contains virtually no sulfur, so SO2 emissions are reduced m direct proportion to the coal replacement. Biomass is a regenerable biofuel. When a fossil fuel is replaced by a biofuel, there is a net reduction in COP emissions. Biomass can contain considerable alkali and alkaline earth elements and chlorine. which, when mixed with other gas components derived from coal such as sulfur compounds, promotes a different array of vapor and fine particulate deposition in coal fired boilers.
Thermogravimetric
analysis
of char combustion
He, R. et al. Combustion Science and Technology, 2002, 174, (4), l-8. Nine different char samples were tested in thermogravimetric analysers with continuously rising temperatures and a global one-step kinetic reaction model was used to describe the char combustion. A mathematical method was presented to deduce the activation energy and pre-exponential factor. The results show that this method has good convergence and is relatively easy for applications. The deduced anparent activation energies and me-exoonential factors will be used for analysing diffusion efiects within char pores in a further study.
10 ENGINES Power generation and propulsion, electrical vehicles
rate
Im, H. G. and Chen, J. H. Combustion and Flume, 2002, 131, (3) 2466 258. The upstream interaction of twin premixed hydrogen-air flames in 2-D turbulence is studied using direct numerical simulations with detailed chemistry. The primary objective is to determine the effect of flame stretch on the overall burning rate during various stages of the interaction. Preferential diffusion effects are accounted for by varying the equivalence ratio from symmetric rich-rich to lean-lean interactions. The results show that the local flame front response to turbulence is consistent with previous understanding of Iaminar premixed flames, in that rich premixed flames become intensified in regions of negative strain or curvature, while the opposite response is found for lean premixed flames. The overall burning rate history with respect to the surface density variation is found to depend on the mixture condition; the consumption rate enhancement advances (follows) the surface enhancement for the rich-rich (lean-lean) case. For the lean-lean case, a self-turbulization mechanism results in a large positive skewness in the area-weighted mean tangential strain statistics. Because of the statistical dominance of positive stretch on the flame surface, the lean-lean case results in a significantly larger burning enhancement (over a twofold increase) in addition to the surface density production, For the case of rich-rich interaction, the abundance in hydrogen species results in an instantaneous overshoot of the radical pool in the post-flame region, resulting in an additional ‘burst’ in the reactant consumption rate history, suggesting its potential impact on the pollutant formation process.
03/01898 Present status and perspectives co-combustion in German power plants
03/01898
03/01899 Condition passage of nitrogen formatton of ignition improvers
of internal-combustion engine fuels by oxides from exhaust gas for in-situ enhancers and cetane number
Degen, W. et ai. U.S. Pat. Appl. Publ. US 2002 144,456 (Cl. 44412; ClOLl/22), 10 Ott 2002, Appl. 10,107,616. An internal-combustion engine fuel is provide in-situ with ignition enhancers and cetane number improvers by passage of nitrogen oxidecontaining gases (consisting of NO, NOa, or N20) through the liquid fuel at 20-150” and atmospheric pressure. The reaction forms into compounds in the fuel hydrocarbons, which act as ignition and combustion enhancers to improve cold-start behaviour. The NO,-type compounds are isolated from the exhaust gases using a storage-type catalytic converter that stores NO, NOz, and N20.
03/01900
Dual fuel diesel engine
Kumakawa, M. et al. Jpn. Kokai Tokkyo Koho JP 2002 309.979 (Cl. F02Dl9/08), 23 Ott 2002, Appl. 2001/l 15,820. 6. (In Japanese) The engine using gas oil as main fuel and CH1-based biogas from anaerobic fermentation of organic waste as fuel, includes a gas inlet pipe connecting with a biogas-supply tube for supplying the gas mixture of air and biogas to the combustion chamber, and a turbocharger for supercharge of the gas mixture without intercooler.
03/01901 Effect of ethanol-unleaded gasoline engine performance and exhaust emission
blends
on
Al-Hasan, M. Energ.)> Conversion and Management, 2003. 44, (9). 15471561. This paper investigates the effect of using unleaded gasoline-ethanol blends on SI engine performance and exhaust emission. A four stroke, four cylinder SI engine (type TOYOTA, TERCEL-3A) was used for conducting this study. Performance tests were conducted for equivalence air-fuel ratio, fuel consumption, volumetric efficiency, brake thermal efficiency, brake power, engine torque and brake specific fuel consumption, while exhaust emissions were analysed for carbon monoxide (CO), carbon dioxide (COa) and unburned hydrocarbons (HC), using unleaded gasoline-ethanol blends with different percentages of fuel at three-fourth throttle opening position and variable engine speed ranging from 1000 to 4000 rpm. The results showed that blending unleaded gasoline with ethanol increases the brake power, torque, volumetric and brake thermal efficiencies and fuel consumption, while it decreases the brake specific fuel consumption and equivalence air-fuel ratio. The CO and HC emissions concentrations in the engine exhaust decrease, while the COa concentration increases. The 20 vol.% ethanol in fuel blend gave the best results for all measured parameters at all engine speeds.
03/01902
Formulated
Gasohol
composition
for automobiles
Song, S. and Wang, Z. Faming Zhuanli Shenqing Gongkai Shuomingshu CN 1,332,227 (Cl. ClOLlIO2) 23 Jan 2002, Appl. 2,001,119,418. (In Chinese) The title composition comprises a gasoline base 65-85, MeOH 10-20, ether compound (especially MTBE) 5-15 weight%, and trace amount of corrosion inhibitor and detergent. The composition is superior in high miscibility, cold ignitability and reducing noxious emissions.
03/01903 Gas turbine combustor for biomass derived gas, a first approach towards fuel-NO, modeling and expertmentsi validation Adouane,
B. et al. Applied Fuel
and
Thermal
Energy
Engineering,
Abstracts
LCV
2002, 22. (8). 959~970.
September
2003
319