电控喷射LPG发动机冷起动失火特性  

Misfiring Characteristics During Cold-Start in an EFI LPG Engine

作　　者：刘志敏[1] 李理光[2] 宫长明[3] 栗工[1] 翟宏斌[1] 邓宝清[3] 

机构地区：[1]上海交通大学教育部动力机械与工程重点实验室,上海200030 [2]同济大学汽车工程学院,上海201804 [3]吉林大学内燃机工程系,长春130025

出　　处：《燃烧科学与技术》2006年第6期545-550,共6页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(50376034);国家"十五"清洁汽车攻关资助项目(2003BA408B09A)

摘　　要：为加强冷起动阶段的排放控制,在一台125 cm3单缸电控喷射LPG点燃式发动机上进行了冷起动失火特性的试验研究.通过程序设计,以电控断点火方式造成发动机在所设定循环的完全失火,研究了冷起动过程不同循环在单循环失火、连续两循环失火和连续三循环失火的起动转速和HC排放,并对冷起动前120循环在不同失火率时的HC排放进行了研究.通过试验找到了影响LPG发动机冷起动过程起动转速和HC排放的关键着火循环,即理想的首次着火循环及其次循环.发动机理想的首次着火循环失火对起动时的HC排放和转速影响最大.在首次着火循环的下一循环失火对起动HC排放影响次之,而其余循环的失火对起动HC排放影响基本相同.提高起动初期发动机转速有利于后续循环的稳定运行.HC排放与失火率呈一定比例关系.失火率增加1倍时,HC排放升高约1倍.当失火率超过500/时,HC排放总量急剧升高.Experiments were conducted in a 125 cm^3 single cylinder EFI SI engine fuelled with LPG. The complete misfiring of designed cycles was created by absence spark ignition. The effect of different cycles during cold-start on start-up speed and HC emissions with single-cycle misfiring, continuous two-cycle and three-cycle misfiring was studied. The HC emissions at different misfiring ratio during the first 120 cycles from cold-start were compared. The key cycle affecting coldstart speed and HC emissions were found experimentally, i.e. the ideal first firing cycle and the next cycle. Misfiring of the ideal first firing cycle has a strong effect on HC and start-up speed in cold start. Misfiring in the next cycle after the ideal first firing cycle affects the HC emissions secondarily. Misfiring of the other cycleshave similar effect on HC emissions. Heightening the start-up speed was helpful for the stabitity of idle running. HC emissions are in a certain proportion to misfiring ratio. With one time increase of misfiring ratio, HC emissions increased by one time approximately. When the misfiring ratio was higher than 5%, the total HC emissions increased rapidly.

关 键 词：失火循环 冷起动 液化石油气 电控喷射 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]