In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about th...In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.展开更多
A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and t...A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.展开更多
将废气再循环(exhaust gas recirculation,EGR)、可变喷嘴涡轮增压器(variable nozzle turbocharger,VNT)与含氧燃料掺烧技术结合,可拓宽EGR的适用工况,提高空燃比,既有助于解决氮氧化物(nitrogen oxides,NOx)与微粒(particulate matter...将废气再循环(exhaust gas recirculation,EGR)、可变喷嘴涡轮增压器(variable nozzle turbocharger,VNT)与含氧燃料掺烧技术结合,可拓宽EGR的适用工况,提高空燃比,既有助于解决氮氧化物(nitrogen oxides,NOx)与微粒(particulate matter,PM)排放的矛盾,也有利于减小海拔上升导致的柴油机性能恶化的程度。选择EGR与VNT耦合的高压共轨柴油机作为研究机型,将生物柴油和生物乙醇按一定比例与柴油混合成生物乙醇柴油(biodiesel-ethanol-diesel,BED)燃料,利用大气模拟系统,在100和80 k Pa的环境下,试验研究VNT与EGR对含氧燃料柴油机动力性、经济性、排放特性的影响规律。结果表明:含氧燃料柴油机的动力性和经济性随着VNT开度和EGR率的增大以及大气压力的降低而变差,在大气压力为80 k Pa、转速为2 200 r/min工况下,VNT开度从22%增大到28%扭矩平均降低3.8 N·m,比油耗平均增加4.2 g/(k W·h),EGR率每增大5%扭矩平均降低0.8 N·m,比油耗平均增加1.5 g/(k W·h),大气压力从100降低至80 k Pa时扭矩平均降低3.4 N·m,比油耗平均增加4.9 g/(k W·h);VNT开度从22%增大到28%时NOx平均减小15%,EGR率每增大5%时NOx排放平均降低12%,大气压力从80增大到100 k Pa时NOx排放平均增加11%;VNT开度从22%增大到28%烟度的平均增幅为175.3%,EGR率每增大5%烟度的平均增幅为331.9%,大气压力从100降低至80 k Pa时烟度的平均增幅为96.6%。展开更多
文摘In order to improve the cold start performance of heavy duty diesel engine, electronically controlling the preheating of intake air by flame was researched. According to simulation and thermodynamic analysis about the partial working processes of the diesel engine, the amount of heat energy, enough to make the fuel self ignite at the end of compression process at different temperatures of coolant and intake air, was calculated. Several HY20 preheating plugs were used to heat up the intake air. Meanwhile, an electronic control system based on 8 bit micro controller unit (MCS 8031) was designed to automatically control the process of heating intake air. According to the various temperatures of coolant and ambient air, one plug or two plugs can automatically be selected to heat intake air. The demo experiment validated that the total system could operate successfully and achieve the scheduled function.
基金Supported by Diesel Engine Development Program of MIIT(DEDP-1004)Natural Science Foundation of BIT(3030012211428)
文摘A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.
文摘将废气再循环(exhaust gas recirculation,EGR)、可变喷嘴涡轮增压器(variable nozzle turbocharger,VNT)与含氧燃料掺烧技术结合,可拓宽EGR的适用工况,提高空燃比,既有助于解决氮氧化物(nitrogen oxides,NOx)与微粒(particulate matter,PM)排放的矛盾,也有利于减小海拔上升导致的柴油机性能恶化的程度。选择EGR与VNT耦合的高压共轨柴油机作为研究机型,将生物柴油和生物乙醇按一定比例与柴油混合成生物乙醇柴油(biodiesel-ethanol-diesel,BED)燃料,利用大气模拟系统,在100和80 k Pa的环境下,试验研究VNT与EGR对含氧燃料柴油机动力性、经济性、排放特性的影响规律。结果表明:含氧燃料柴油机的动力性和经济性随着VNT开度和EGR率的增大以及大气压力的降低而变差,在大气压力为80 k Pa、转速为2 200 r/min工况下,VNT开度从22%增大到28%扭矩平均降低3.8 N·m,比油耗平均增加4.2 g/(k W·h),EGR率每增大5%扭矩平均降低0.8 N·m,比油耗平均增加1.5 g/(k W·h),大气压力从100降低至80 k Pa时扭矩平均降低3.4 N·m,比油耗平均增加4.9 g/(k W·h);VNT开度从22%增大到28%时NOx平均减小15%,EGR率每增大5%时NOx排放平均降低12%,大气压力从80增大到100 k Pa时NOx排放平均增加11%;VNT开度从22%增大到28%烟度的平均增幅为175.3%,EGR率每增大5%烟度的平均增幅为331.9%,大气压力从100降低至80 k Pa时烟度的平均增幅为96.6%。
