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01737 Large eddy simulation of a model gas turbinecombustor
10 Engines (power generation and propulsion, electrical vehicles) Cottonseed oil has been used as a fuel source either as a blend with diesel in varying proportions or undiluted (100%) in numerous studies evaluating its potential use in internal combustion engines. However, limited research is available on the use of cottonseed oil as a fuel source in a multi-fuelled burner similar to those used by cottonseed oil mills and cotton gins in their drying operations. The purpose of this study was to evaluate emissions from five fuel oil treatments while firing a multi-fuelled burner in a set-up similar to those used for drying operations of both cottonseed oil mills and cotton gins. For each treatment, gaseous emissions were measured while firing the burner at three fuel flow rates. The five fuel oil treatments evaluated were: (1) No. 2 diesel at 28.3°C, (2) prime bleachable summer yellow (PBSY) cottonseed oil at 28.3°C (PBSY-28), (3) crude cottonseed oil at 28.3°C (Crude-28), (4) PBSY at 60°C (PBSY-60), and (5) crude at 60°C (Crude-60). Results indicate that PBSY treatments had the lowest overall emissions of all treatments. The other treatments varied in emission rates based on treatment and fuel flow rate. Preheating the oii to 60°C resulted in higher NOx emissions but displayed varying results in regards to CO. The CO emissions for the crude treatments were relatively unaffected by the 60°C preheat temperature whereas the preheated PBSY treatments demonstrated lower CO emissions. Overa1I, both cottonseed oils performed well in the multi-fuelled burner and displayed a promising potential as an alternative fuel source for cottonseed oil mills and cotton gins in their drying operations.
05•01737 Large eddy simulation of a model gas turbine combustor di Mare, F. et al. Combustion and Flame, 2004, 137, (3), 278-294. Large eddy simulation (LES) has been used to predict temperature and species concentrations in a model can-type gas turbine combustor operating in a non-premixed combustion regime. The subgrid scale stresses have been modelled adopting the standard Smagorinsky-Lilly model, whilst combustion has been accounted for using a conserved scalar approach. The dependence of the thermodynamicat status of the mixture on the conserved scalar has been described invoking a flamelet assumption, and the shape of the scalar probability density function (pdf) assigned to be a t3 function. The subgrid scalar variance, needed to parameterize the scalar pdf, has been modelled according to local equilibrium arguments. The complex flow pattern developing from the interaction of a strongly swirling flow in the primary zone with the impinging primary jets has been captured by the present simulations in great detail. In particular, it has been observed that an accurate description of the inlet section of the combustor plays a fundamental role in the prediction of the fuel placement and, hence, of the temperature distribution in the primary region.
05•01738 Modelling and dynamic simulation of a fuel cell system with an autothermal gasoline reformer Sommer, M. et al. Journal of Power Sources, 2004, 127, (1-2), 313 318. In order to describe the dynamic behaviour of a fuel cell system its components are modelled by the help of 1D dynamic models which are implemented in Matlab Simulink. The fuel cell system consists of an autothermal gasoline reformer (ATR) which for the realization of a high system efficiency is thermally coupled to the other system components (gas purification, heat exchangers). Dynamic simulations of load changes show that the dynamic behaviour of such a system is primarily dominated by the response times of the liquid water flowing through the heat exchangers, the volume of which should consequently be reduced to a minimum in order to achieve shorter response times. In contrast, the dynamic behaviour of the reactors is not critical. The composition of the product gas at the ATR-outlet is however infuenced by the moisture content of the gas at the A T R inlet, which in turn is negatively influenced for a short transition period by the residence times of the water flowing through the heat exchangers during a load change. According to the results obtained, the system is able to adjust to load changes within 20 s for a load increase (10-90% of full load) and within 3 s for a load decrease (90-10% of full load).
05•01739 Optimum design of a subsonic axial-flow compressor stage Chen, L. et al. Applied Energy, 2005, 80, (2), 187 195. The design of an axial-flow compressor stage for sub-critical Mach numbers has been formulated as a non-linear multi-objective mathematical programming problem with the objective of minimizing the aerodynamic losses and the weight of the stage, while maximizing the compressor's stall margin. Aerodynamic as well as mechanical constraints are considered in the optimization solution. The prediction model for estimating the performance characteristics, such as efficiency, weight and stall margin, of the compressor stage is presented. The present design optimization procedure can be applied to a multi-stage compressor.
256
Fuel and Energy Abstracts July 2005
05•01740 Performance and emission study of Mahua oil (Madhuca indica oil) ethyl ester in a 4-stroke natural aspirated direct injection diesel engine Puhan, S. et al. Renewable Energy, 2005, 30, (8), 1269-1278. In this investigation, Mahua Oil Ethyl Ester was prepared by transesterification using sulfuric acid (H2SO4) as catalyst and tested in a 4-stroke direct injection natural aspirated diesel engine. Tests were carried out at constant speed of 1500 rev/min at different brake mean effective pressures. Results showed that brake thermal efficiency of Mahua Oil Ethyl Ester (MOEE) was comparable with diesel and it was observed that 26.36% for diesel whereas 26.42% for MOEE. Emissions of carbon monoxide, hydrocarbons, oxides of nitrogen and Bosch smoke number were reduced around 58, 63, 12 and 70%, respectively, in case of MOEE compared to diesel. Based on this study, MOEE can be used a substitute for diesel in diesel engine.
05•01741 Physico-chemical properties of ethanol-diesel blend fuel and its effect on performance and emissions of diesel engines Li, D. et al. Renewable Energy, 2005, 30, (6), 967-976. The effects of different ethanol-diesel blended fuels on the performance and emissions of diesel engines have been evaiuated experimentally and compared in this paper. The purpose of this project is to find the optimum percentage of ethanol that gives simultaneously better performance and lower emissions. The experiments were conducted on a water-cooled singie-cylinder Direct Injection (DI) diesel engine using 0% (neat diesel fuel), 5% (E5-D), 10% (E10-D), 15% (E15-D), and 20% (E20-D) ethanol-diesel blended fuels. With the same rated power for different blended fuels and pure diesel fuel, the engine performance parameters (including power, torque, fuel consumption, and exhaust temperature) and exhaust emissions [Bosch smoke number, CO, NOx, total hydrocarbon (THC)] were measured. The results indicate that: the brake specific fuel consumption and brake thermal efficiency increased with an increase of ethanol contents in the blended fuel at overall operating conditions; smoke emissions decreased with ethanol-diesel blended fuel, especiaiIy with El0 D and E15-D. CO and NOx emissions reduced for ethanol-diesel blends, but T H C increased significantly when compared to neat diesel fuel.
05•01742 Pulse detonation propulsion: challenges, current status, and future perspective Roy, G. D. et al. Progress in Energy and Combustion Science, 2004, 30, (6), 545-672. The paper is focused on recent accomplishments in basic and applied research on pulse detonation engines (PDE) and various PDE design concepts. Current understanding of gas and spray detonations, thermodynamic grounds for detonation-based propulsion, principles of practical implementation of the detonation-based thermodynamic cycle, and various operational constraints of PDEs are discussed.
05101743 Selective catalytic reduction of nitrogen oxides from exhaust of lean burn engine over in situ synthesized monolithic Cu-TS-1/cordierite Li, L. et al. Catalysis Today, 2004, 90, (3 4), 207-213. Titanium silicalite (TS-1) zeolite was in situ synthesized successfully on the surface of honeycomb cordierite substrate, which was certified by XRD and SEM techniques. The in situ synthesized monolithic TS-1/ cordierite showed superior thermal and hydrothermal stabilities. C u TS-1/cordierite prepared with ion-exchange and impregnation methods were studied as catalysts for selective catalytic reduction (SCR) of nitrogen oxides (NOz). For practicality, the evaluation experiments were carried out in exhaust of a real lean burn engine without any other additive. Cu-TS-1/cordierite prepared with two methods both exhibited similar high activities, and at about 715 K, the max NOx conversion could reach 58% in the space velocity (SV) of 12000 h -1. Ion-exchanged Cu-TS-1/cordierite had superior duration and antipoison properties while impregnated Cu-TS-1/cordierite not. Cooper is the main active component in the catalyst and Cu(I), which was found in the catalyst during the proceeding of reaction by XPS, is thought to be essential.
05/01744 Shock-tube study of methane ignition under engine-relevant conditions: experiments and modeling Huang, J. et al. Combustion and Flame, 2004, 136, (1-2), 25-42. A series of shock tube experiments was conducted to measure the ignition delay of homogeneous methane/air (CH4/air) mixtures at moderate temperatures (1000-1350 K) and elevated pressures (16-40 atm). The equivalence ratios of the test mixtures were varied from 0.7 to 1.3 with the focus on the slightly lean-to-stoichiometric region, which is most relevant to internal combustion (IC) engine conditions. Transitions from mild to strong ignition were observed at lower temperatures with increasing pressure. An analytical study of methane oxidation under the above conditions was conducted using a detailed chemical kinetic mechanism proposed elsewhere. The mechanism was modified and extended in this work, based on the experimental results
05•01737 Large eddy simulation of a model gas turbine combustor di Mare, F. et al. Combustion and Flame, 2004, 137, (3), 278-294. Large eddy simulation (LES) has been used to predict temperature and species concentrations in a model can-type gas turbine combustor operating in a non-premixed combustion regime. The subgrid scale stresses have been modelled adopting the standard Smagorinsky-Lilly model, whilst combustion has been accounted for using a conserved scalar approach. The dependence of the thermodynamicat status of the mixture on the conserved scalar has been described invoking a flamelet assumption, and the shape of the scalar probability density function (pdf) assigned to be a t3 function. The subgrid scalar variance, needed to parameterize the scalar pdf, has been modelled according to local equilibrium arguments. The complex flow pattern developing from the interaction of a strongly swirling flow in the primary zone with the impinging primary jets has been captured by the present simulations in great detail. In particular, it has been observed that an accurate description of the inlet section of the combustor plays a fundamental role in the prediction of the fuel placement and, hence, of the temperature distribution in the primary region.
05•01738 Modelling and dynamic simulation of a fuel cell system with an autothermal gasoline reformer Sommer, M. et al. Journal of Power Sources, 2004, 127, (1-2), 313 318. In order to describe the dynamic behaviour of a fuel cell system its components are modelled by the help of 1D dynamic models which are implemented in Matlab Simulink. The fuel cell system consists of an autothermal gasoline reformer (ATR) which for the realization of a high system efficiency is thermally coupled to the other system components (gas purification, heat exchangers). Dynamic simulations of load changes show that the dynamic behaviour of such a system is primarily dominated by the response times of the liquid water flowing through the heat exchangers, the volume of which should consequently be reduced to a minimum in order to achieve shorter response times. In contrast, the dynamic behaviour of the reactors is not critical. The composition of the product gas at the ATR-outlet is however infuenced by the moisture content of the gas at the A T R inlet, which in turn is negatively influenced for a short transition period by the residence times of the water flowing through the heat exchangers during a load change. According to the results obtained, the system is able to adjust to load changes within 20 s for a load increase (10-90% of full load) and within 3 s for a load decrease (90-10% of full load).
05•01739 Optimum design of a subsonic axial-flow compressor stage Chen, L. et al. Applied Energy, 2005, 80, (2), 187 195. The design of an axial-flow compressor stage for sub-critical Mach numbers has been formulated as a non-linear multi-objective mathematical programming problem with the objective of minimizing the aerodynamic losses and the weight of the stage, while maximizing the compressor's stall margin. Aerodynamic as well as mechanical constraints are considered in the optimization solution. The prediction model for estimating the performance characteristics, such as efficiency, weight and stall margin, of the compressor stage is presented. The present design optimization procedure can be applied to a multi-stage compressor.
256
Fuel and Energy Abstracts July 2005
05•01740 Performance and emission study of Mahua oil (Madhuca indica oil) ethyl ester in a 4-stroke natural aspirated direct injection diesel engine Puhan, S. et al. Renewable Energy, 2005, 30, (8), 1269-1278. In this investigation, Mahua Oil Ethyl Ester was prepared by transesterification using sulfuric acid (H2SO4) as catalyst and tested in a 4-stroke direct injection natural aspirated diesel engine. Tests were carried out at constant speed of 1500 rev/min at different brake mean effective pressures. Results showed that brake thermal efficiency of Mahua Oil Ethyl Ester (MOEE) was comparable with diesel and it was observed that 26.36% for diesel whereas 26.42% for MOEE. Emissions of carbon monoxide, hydrocarbons, oxides of nitrogen and Bosch smoke number were reduced around 58, 63, 12 and 70%, respectively, in case of MOEE compared to diesel. Based on this study, MOEE can be used a substitute for diesel in diesel engine.
05•01741 Physico-chemical properties of ethanol-diesel blend fuel and its effect on performance and emissions of diesel engines Li, D. et al. Renewable Energy, 2005, 30, (6), 967-976. The effects of different ethanol-diesel blended fuels on the performance and emissions of diesel engines have been evaiuated experimentally and compared in this paper. The purpose of this project is to find the optimum percentage of ethanol that gives simultaneously better performance and lower emissions. The experiments were conducted on a water-cooled singie-cylinder Direct Injection (DI) diesel engine using 0% (neat diesel fuel), 5% (E5-D), 10% (E10-D), 15% (E15-D), and 20% (E20-D) ethanol-diesel blended fuels. With the same rated power for different blended fuels and pure diesel fuel, the engine performance parameters (including power, torque, fuel consumption, and exhaust temperature) and exhaust emissions [Bosch smoke number, CO, NOx, total hydrocarbon (THC)] were measured. The results indicate that: the brake specific fuel consumption and brake thermal efficiency increased with an increase of ethanol contents in the blended fuel at overall operating conditions; smoke emissions decreased with ethanol-diesel blended fuel, especiaiIy with El0 D and E15-D. CO and NOx emissions reduced for ethanol-diesel blends, but T H C increased significantly when compared to neat diesel fuel.
05•01742 Pulse detonation propulsion: challenges, current status, and future perspective Roy, G. D. et al. Progress in Energy and Combustion Science, 2004, 30, (6), 545-672. The paper is focused on recent accomplishments in basic and applied research on pulse detonation engines (PDE) and various PDE design concepts. Current understanding of gas and spray detonations, thermodynamic grounds for detonation-based propulsion, principles of practical implementation of the detonation-based thermodynamic cycle, and various operational constraints of PDEs are discussed.
05101743 Selective catalytic reduction of nitrogen oxides from exhaust of lean burn engine over in situ synthesized monolithic Cu-TS-1/cordierite Li, L. et al. Catalysis Today, 2004, 90, (3 4), 207-213. Titanium silicalite (TS-1) zeolite was in situ synthesized successfully on the surface of honeycomb cordierite substrate, which was certified by XRD and SEM techniques. The in situ synthesized monolithic TS-1/ cordierite showed superior thermal and hydrothermal stabilities. C u TS-1/cordierite prepared with ion-exchange and impregnation methods were studied as catalysts for selective catalytic reduction (SCR) of nitrogen oxides (NOz). For practicality, the evaluation experiments were carried out in exhaust of a real lean burn engine without any other additive. Cu-TS-1/cordierite prepared with two methods both exhibited similar high activities, and at about 715 K, the max NOx conversion could reach 58% in the space velocity (SV) of 12000 h -1. Ion-exchanged Cu-TS-1/cordierite had superior duration and antipoison properties while impregnated Cu-TS-1/cordierite not. Cooper is the main active component in the catalyst and Cu(I), which was found in the catalyst during the proceeding of reaction by XPS, is thought to be essential.
05/01744 Shock-tube study of methane ignition under engine-relevant conditions: experiments and modeling Huang, J. et al. Combustion and Flame, 2004, 136, (1-2), 25-42. A series of shock tube experiments was conducted to measure the ignition delay of homogeneous methane/air (CH4/air) mixtures at moderate temperatures (1000-1350 K) and elevated pressures (16-40 atm). The equivalence ratios of the test mixtures were varied from 0.7 to 1.3 with the focus on the slightly lean-to-stoichiometric region, which is most relevant to internal combustion (IC) engine conditions. Transitions from mild to strong ignition were observed at lower temperatures with increasing pressure. An analytical study of methane oxidation under the above conditions was conducted using a detailed chemical kinetic mechanism proposed elsewhere. The mechanism was modified and extended in this work, based on the experimental results