摘要
利用GT-Power和Chemkin软件建立了采用早期排气道EGR策略的汽油机模型。利用该模型分析了早期排气道EGR策略中排气门关闭角、进气门关闭角、进气门开启角对EGR率的影响;分析了相同机型采用SI燃烧方式时进气门晚关角和排气门晚关角对容积效率的影响;对比了CAI燃烧方式(采用早期排气道EGR策略)和SI燃烧方式(经过气门相位优化后)发动机的动力性、经济性。计算结果表明:进气门关闭角对EGR率的影响很小;排气门关闭角和进气门开启角在不同定时区域对EGR率起到不同程度的影响;只有EGR率较低时,发动机采用CAI燃烧方式的动力性、经济性才优于采用SI燃烧方式时,随着EGR率的升高,发动机的动力性、经济性越来越差。
The gasoline engine model of early exhaust duct EGR strategy was built with GT-Power and Chemkin software. With the model,the influences of exhaust valve closing（EVC）angle,intake valve closing（IVC）angle and intake valve opening（IVO）angle on EGR rate were analyzed.The influences of intake valve late closing angle and exhaust valve late closing angle on volumetric efficiency in SI combustion mode were analyzed.And the engine power and economy under CAI combustion mode（with early exhaust duct EGR）and SI combustion mode（after optimization of valve timing）were compared.The results show that the IVC angle has a little influence on EGR rate.The EVC angle and IVO angle have different influences on EGR rate in different regions.Only when EGR rate is low,the power and economy of CAI combustion mode are superior to that of SI combustion mode.With the increase of EGR rate,the power and economy become worse.
出处
《车用发动机》
北大核心
2014年第2期57-61,共5页
Vehicle Engine
关键词
可控自燃
火花点燃
配气相位
废气再循环
数值模拟
controlled auto-ignition
spark ignition
valve timing
EGR
numerical simulation
