In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties...In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties are rather better with different optimizing index when the ratio of bio-diesel, ethanol and diesel are 71.58:2.72:25.70 and 50:2.4127:47.5873.展开更多
Using renewable fuels for diesel engines can reduce both air pollution and dependence on fossil fuels.A computer simulation was constructed to predict the performance,combustion characteristics,and NOx emissions of a ...Using renewable fuels for diesel engines can reduce both air pollution and dependence on fossil fuels.A computer simulation was constructed to predict the performance,combustion characteristics,and NOx emissions of a diesel engine fuelled with diesel-biodiesel-butanol blends.The simulation was validated by comparing the modelling results against experimental data and a good agreement between the results was found.The fuels used for the validation were diesel(B0),biodiesel(B100),diesel-biodiesel blend(B50),and two diesel-biodiesel-butanol blends with 45%diesel-45%biodiesel-10%butanol(Bu10)and 40%diesel-40%biodiesel-20%butanol(Bu20)by volume.Experimental results showed that the addition of butanol reduced NOx emissions but deteriorated the engine performance.The aim of the current work was the numerical optimization of the different parameters to enhance the engine performance while using butanol to decrease NOx emissions.The engine compression ratio(CR)varied from 14 to 24,in increments of 2.Fuel injection timing(IT)was reduced from 30°before top dead centre(bTDC)to 5°bTDC in increments of 5°.Also,the fuel injection duration(IDur)was extended from 20°to 50°in increments of 10°.Results showed that the increase in the CR improved engine performance for the two investigated fuels,Bu10 and Bu20.The maximum engine brake power(BP),thermal efficiency(BTE),and minimum brake-specific fuel consumption(BSFC)of 1.46 kW,32.3%,and 0.273 kg/kWh respectively,were obtained when the Bu10 fuel was injected under the optimum conditions of 24 CR,15°bTDC IT,and 40°IDur.Under these optimum conditions,the BP,BTE,and BSFC improved by 3%-3.5%for Bu10 and Bu20 fuel blends compared with the base engine conditions of a CR of 22,30°IDur,and 10°bTDC IT.The heat release rate during the premixed phase increased when the IT was advanced,while the mixing-controlled combustion phase was enhanced when the IT was reduced.NOx emissions increased with increasing CR,while both an increase in IDur at constant IT and the reduction of the IT decreased the engine NOx emissions.Under the optimum conditions,the NOx emissions for Bu10 and Bu20 were further decreased by 2.2%and 0.9%,respectively,compared with the experimental results under base engine conditions.Reducing the IT from 15°to 5°bTDC at a CR of 24 and IDur of 40°caused the NOx emissions for Bu10 and Bu20 to decrease by 16%.When the IDur was increased from 20°to 50°at a CR of 24 and an IT of 15°bTDC,the NOx emissions for Bu10 and Bu20 decreased by 12.3%and 11.8%,respectively.The addition of butanol to the diesel-biodiesel blend under optimum conditions showed results that were comparable to those of pure diesel,with a decrease in NOx emissions.展开更多
提出了基于排气氧浓度的判断方法来判断车辆发动机实时燃用的生物柴油混合燃料的混合比例。根据燃烧及进排气过程质量守恒的原理推导出生物柴油混合比例关于排气氧含量、进气空气质量、喷油量等变量的计算模型,并建立了混合比例判断策...提出了基于排气氧浓度的判断方法来判断车辆发动机实时燃用的生物柴油混合燃料的混合比例。根据燃烧及进排气过程质量守恒的原理推导出生物柴油混合比例关于排气氧含量、进气空气质量、喷油量等变量的计算模型,并建立了混合比例判断策。搭建了由发动机控制单元(engine control unit,ECU)、Mototron快速原型控制器等组成的生物柴油混合比例测量系统,采用五种不同已知混合比例的生物柴油进行发动机台架试验验证。研究结果表明:上述策略在中高负荷工况且燃用高混合比例生物柴油的条件下可以较准确地判断出生物柴油混合比例,在低负荷工况且燃用低混合比例生物柴油的条件下判断策略的精度较低。展开更多
文摘In this paper, we study the best-mixture ratio of biodiesel-ethanol-diesel for diesel engines. The simulation results show that the integrated indexes including engine power, cost-effectiveness and emission properties are rather better with different optimizing index when the ratio of bio-diesel, ethanol and diesel are 71.58:2.72:25.70 and 50:2.4127:47.5873.
文摘Using renewable fuels for diesel engines can reduce both air pollution and dependence on fossil fuels.A computer simulation was constructed to predict the performance,combustion characteristics,and NOx emissions of a diesel engine fuelled with diesel-biodiesel-butanol blends.The simulation was validated by comparing the modelling results against experimental data and a good agreement between the results was found.The fuels used for the validation were diesel(B0),biodiesel(B100),diesel-biodiesel blend(B50),and two diesel-biodiesel-butanol blends with 45%diesel-45%biodiesel-10%butanol(Bu10)and 40%diesel-40%biodiesel-20%butanol(Bu20)by volume.Experimental results showed that the addition of butanol reduced NOx emissions but deteriorated the engine performance.The aim of the current work was the numerical optimization of the different parameters to enhance the engine performance while using butanol to decrease NOx emissions.The engine compression ratio(CR)varied from 14 to 24,in increments of 2.Fuel injection timing(IT)was reduced from 30°before top dead centre(bTDC)to 5°bTDC in increments of 5°.Also,the fuel injection duration(IDur)was extended from 20°to 50°in increments of 10°.Results showed that the increase in the CR improved engine performance for the two investigated fuels,Bu10 and Bu20.The maximum engine brake power(BP),thermal efficiency(BTE),and minimum brake-specific fuel consumption(BSFC)of 1.46 kW,32.3%,and 0.273 kg/kWh respectively,were obtained when the Bu10 fuel was injected under the optimum conditions of 24 CR,15°bTDC IT,and 40°IDur.Under these optimum conditions,the BP,BTE,and BSFC improved by 3%-3.5%for Bu10 and Bu20 fuel blends compared with the base engine conditions of a CR of 22,30°IDur,and 10°bTDC IT.The heat release rate during the premixed phase increased when the IT was advanced,while the mixing-controlled combustion phase was enhanced when the IT was reduced.NOx emissions increased with increasing CR,while both an increase in IDur at constant IT and the reduction of the IT decreased the engine NOx emissions.Under the optimum conditions,the NOx emissions for Bu10 and Bu20 were further decreased by 2.2%and 0.9%,respectively,compared with the experimental results under base engine conditions.Reducing the IT from 15°to 5°bTDC at a CR of 24 and IDur of 40°caused the NOx emissions for Bu10 and Bu20 to decrease by 16%.When the IDur was increased from 20°to 50°at a CR of 24 and an IT of 15°bTDC,the NOx emissions for Bu10 and Bu20 decreased by 12.3%and 11.8%,respectively.The addition of butanol to the diesel-biodiesel blend under optimum conditions showed results that were comparable to those of pure diesel,with a decrease in NOx emissions.
文摘提出了基于排气氧浓度的判断方法来判断车辆发动机实时燃用的生物柴油混合燃料的混合比例。根据燃烧及进排气过程质量守恒的原理推导出生物柴油混合比例关于排气氧含量、进气空气质量、喷油量等变量的计算模型,并建立了混合比例判断策。搭建了由发动机控制单元(engine control unit,ECU)、Mototron快速原型控制器等组成的生物柴油混合比例测量系统,采用五种不同已知混合比例的生物柴油进行发动机台架试验验证。研究结果表明:上述策略在中高负荷工况且燃用高混合比例生物柴油的条件下可以较准确地判断出生物柴油混合比例,在低负荷工况且燃用低混合比例生物柴油的条件下判断策略的精度较低。
