【作者】 楼狄明； 赵彬皓； 房亮；

【Author】 Lou Diming;Zhao Binhao;Fang Liang;College of Automotive Studies,Tongji University;

【机构】 同济大学汽车学院；

【摘要】 本试验利用一台1.5L高压缩比增压直喷汽油机对比研究了不同稀释燃烧方式对低速小负荷工况发动机性能的影响规律。结果表明,过量空气稀释和废气稀释均增大了缸内最高压力,延长了着火落后期与燃烧持续期,减少了泵气损失,降低了有效燃油消耗率,但会使循环波动增大;过量空气稀释的泵气损失更大,循环波动更小,油耗更低;同时引入过量空气与废气的复合稀释燃烧可在稀释率较小时进一步降低燃油消耗率,但此时NO_x与颗粒物排放无明显改善;大稀释率下,随着废气稀释占比增大,复合稀释燃烧的排气温度小幅上升,NO_x排放先升高后降低,颗粒物排放数量则呈现大幅上升趋势。更多还原

【Abstract】 In order to compare the effect of lean burn,EGR(Emission Gas Recirculation) and lean dilution combustion on engine performance at low speed and low load conditions,a 1.5 L turbocharged direct injection gasoline engine with high compression ratio was used to conduct a bench test.The results show that both lean burn and EGR increase the maximum in-cylinder pressure,extend the ignition delay period and combustion duration,reduce pumping mean effective losses and the brake specific fuel consumption,but increase the cycle fluctuation.And lean burn has higher pumping losses,lower cycle fluctuation and fuel consumption compared with EGR.Besides,at small dilution rate,lean dilution combustion with air and exhaust gas can further reduce the fuel consumption,but the emission of NO_x and particulate emission number(PN) has no obvious reduce.At high dilution rate of lean dilution combustion,as the proportion of EGR increases,the exhaust gas temperature increases slightly,the NO_xemission increases first and then decreases,and the PN emission shows an significant increasing trend.更多还原