PFI汽油机快速拖动起动控制策略与碳氢排放  

Analysis of Control Strategies and Hydrocarbon Emission Behavior of PFI Gasoline Engine during High-Speed Cranking Start

作　　者：周健豪[1] 袁银男[2] 柳先强[1] 陈笃红[1] 王存磊 

机构地区：[1]江苏大学汽车电子技术研究所,镇江212013 [2]南通大学机械工程学院,南通226019 [3]上海华普汽车有限公司,上海201501

出　　处：《内燃机工程》2011年第5期1-6,共6页Chinese Internal Combustion Engine Engineering

基　　金：国家"八六三"高技术研究发展计划项目(2006AA11A128)

摘　　要：搭建了汽油机起动过程模拟试验平台,对比分析了采用普通起动马达和ISG(起动/发电一体化)电机高转速拖动起动时,汽油机的瞬时转速、气缸压力、燃油补偿系数、进气压力、点火时刻、HC转化效率、排气温度及瞬态HC排放浓度的变化规律。试验结果表明:随着拖动转速升高,进气压力降低,进气量减少,燃油蒸发时间缩短,雾化不充分,缸内发生失火的可能性增加,瞬态排放急剧升高,并与冷却液温度有着对应关系。通过瞬态燃油补偿可以改善汽油机起动后若干工作循环混合气偏稀的情况,降低HC排放。推迟点火,可提高排气温度,但冷机和热机状况下三效催化器转化效率存在较大差异。暖机后,当点火提前角为-10°CA时,三效催化器能在40s内起燃,HC转化率在60s内达到90%左右。The comparative analysis of prototype engine between conventional starting motor start and high-speed cranking start with ISG（integrate starter/generator） was carried out to examine the variation regulation of engine transient speed,cylinder pressure,fuel compensation factor,intake air pressure,ignition timing,HC conversion efficiency,exhaust temperature and transient HC emission.The results show that,with cranking speed increasing,the intake pressure drops,causing the intake air quantity reduces,and fuel-film evaporation time shortens,the mixture atomization gets insufficient.The misfire occurs and the transient HC emission peak arises.All these phenomena have close relationship with ECT（engine coolant temperature）.Fuel compensation in the first few working cycles of starting process can correct original lean mixture so as to decrease HC emission.Retarding ignition can raise the exhaust gas temperature.The conversion efficiency of three-way catalytic converter（TWC） in cold and warmed-up conditions is quite different.When engine is warmed up and the ignition timing is-10°CA,the TWC lights off within 40s and its HC conversion efficiency reaches about 90% within 60s.

关 键 词：内燃机 汽油机 混合动力轿车 起动/发电一体化电机 拖动起动 燃烧特性 排放特性 

分 类 号：TK413.7[动力工程及工程热物理—动力机械及工程]