基于循环控制的LPG电喷发动机冷起动初探.PDFVIP

EME 基于循环控制的LPG电喷发动机冷起动初探* 1 1 1 1 1 2 王振锁 王惠萍 邓宝清 肖宗成 苏 岩 李理光 (1 吉林大学 2 上海交通大学) 【摘 要】本文介绍了基于循环控制方法的 LPG 发动机冷起动特性研究。试验在一台四行程、水冷 125ml 单缸电 控喷射点燃式发动机上进行。通过对冷起动循环的缸压和瞬时转速的实时测量和分析，研究了LPG首次喷射脉宽 及着火循环的关系对冷起动着火特性的影响， 特别对如何实现可控循环着火进行了基于单次起动喷射脉宽的单 循环和多循环燃烧研究。试验结果表明：冷起动首次着火循环对整个起动过程的 HC 排放及着火稳定性起着至关 重要的作用；起动喷射脉宽对冷起动着火特性的影响最大，合理控制起动喷射脉宽和喷射时刻，即可实现“即喷 即着”的理想可控循环着火。LPG首次着火循环所需的混合气浓度约是稳定怠速时的2.2倍；单次起动喷射脉宽 起动与多循环起动脉宽起动相比，具有 HC 排放低和起动可靠性好的优点。在首次喷射之前空转几循环可以使发 动机的首次着火循环序数提前，并能提高冷起动可靠性。 关键词：LPG发动机；冷起动；起动循环；脉宽控制 Investigation of Cold-start Based on Cycle-by-Cycle Control Strategy in a LPG EFI Engine 1 1 1 1 1 2 Wang Zhensuo , Wang Huiping , Deng Baoqing , Xiao Zongcheng , Su Yan , Li Liguang (1, Jilin University 2, Shanghai Jiaotong University) Abstract: This paper presents an investigation of cold start based on cycle-by-cycle control strategy in a LPG EFI engine. Experiments are carried out in a four-stroke, water-cooled, single cylinder, 125cc SI engine with EFI system. Effects of the first injection pulse width and the first firing cycle on the characteristics of cold starting were analyzed based on the histories of transient engine speeds and cylinder pressures. The study focuses on how to realize the controllable ignition cycle and the single-cycle and multi-cycle combustions were tested based on the single starting injection pulse width. Test results show that: the first firing cycle has an important effect on HC emission and combustion