低压空气辅助喷射甲醇发动机冷起动试验研究  

Experimental Study on Cold Start of A Low Pressure Air Assisted Injection Methanol Engine

作　　者：胡春明[1,2] 马建义 何永辉 刘娜[1] 宋玺娟[1] 杜春媛 HU Chunming;MA Jianyi;HE Yonghui;LIU Na;SONG Xijuan;DU Chunyuan(Internal Combustion Engine Research Institute,Tianjin University,Tianjin 300072,China;School of Mechanical Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学内燃机研究所,天津300072 [2]天津大学机械工程学院,天津300072

出　　处：《内燃机工程》2023年第2期64-72,80,共10页Chinese Internal Combustion Engine Engineering

摘　　要：针对甲醇发动机难以形成浓度合适的混合气而造成冷起动困难的问题,以一台应用自主开发的进气道低压空气辅助喷射系统(air assisted port injection,AAPI)的单缸甲醇发动机为研究对象开展试验研究,探究不采用辅助措施通过AAPI喷射实现甲醇高雾化对甲醇发动机冷起动的影响及规律。试验表明AAPI明显加快了甲醇发动机冷起动前可燃混合气的形成速率。AAPI甲醇发动机着火前过量空气系数λ的平均变化率值和峰值变化率分别是普通喷射方式的3.2倍和2.26倍。点火时刻对AAPI甲醇发动机冷起动影响较大,为使AAPI甲醇发动机的冷起动性能最优,需配合合适的点火时刻,试验条件下最佳点火时刻为活塞压缩上止点前20°。AAPI甲醇发动机的冷起动性能受环境温度影响较大,随着环境温度的降低,甲醇发动机冷起动时间增长;不采用辅助措施,AAPI甲醇发动机在5℃时能实现可靠冷起动。In view of the difficulty in cold start of a methanol engine caused by the difficulty in forming a mixture with appropriate concentration,a single-cylinder methanol engine with the self-developed air assisted port injection system(AAPI)was taken as the research object to carry out experimental research.Without auxiliary measures,the effects and law of high methanol atomization through AAPI on the cold start of a methanol engine were explored.Results show that AAPI obviously speeds up the formation rate of combustible mixture before the cold start of the methanol engine.The average change rate and the peak change rate of excess air coefficientλbefore starting of the methanol engine with AAPI were 3.2 times and 2.26 times those of the methanol engine with port fuel injection,respectively.The ignition time has a great influence on the cold start of the methanol engine with AAPI.Therefore,to optimize the cold start performance of the methanol engine with AAPI,it is necessary to select an appropriate ignition time.And the optimum ignition time is 20°before the dead center in the test conditions.The ambient temperature also has a great influence on the cold start performance of the methanol engine with AAPI.With the decrease of the ambient temperature,the cold start time gets longer.And the methanol engine with AAPI can realize reliable cold start at 5℃.

关 键 词：低压空气辅助喷射 甲醇发动机 冷起动 喷雾粒径 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]