点火和喷射正时对甲醇发动机冷起动特性的影响  

Effects of Ignition and Injection Timing on Cold Start Behavior of Methanol Engine

作　　者：宫长明[1] 王舒[2] 邓宝清[1] 苏岩[1] 刘巽俊[1] 

机构地区：[1]吉林大学汽车工程学院,长春130022 [2]中国汽车工程研究院国家燃气汽车工程技术中心,重庆400039

出　　处：《西安交通大学学报》2008年第11期1367-1371,共5页Journal of Xi'an Jiaotong University

基　　金：国家自然科学基金资助项目(50576031)

摘　　要：在一台125 mL的单缸电控喷射点燃式甲醇发动机上进行了冷起动瞬态工况着火特性的试验研究.基于循环控制研究了点火正时和喷射正时对甲醇发动机冷起动的着火特性和HC排放的影响.试验结果表明:点火正时和喷射正时对甲醇发动机的冷起动着火特性和HC排放均有显著影响;推迟点火从-20°(上止点前,下同)到10°,发动机的后燃逐渐增多,气缸压力逐渐降低,直至最后不能起动,甲醇发动机点火正时优化为-20°;喷射正时比点火正时对冷起动着火特性影响更显著,合理控制起动喷射正时,可保证混合气全部在受控的着火循环时进入气缸,实现"即喷即着"的理想着火,并提高发动机的着火可靠性;曲轴转角为471°(上止点后)喷射甲醇比-35°喷射甲醇时的气缸最高燃烧压力提高了140%,HC排放降低了65%.The firing behavior of a 125 mL single cylinder methanol engine with electronically controlled injection spark-ignition at cold start was investigated experimentally. The effects of the injection timing and the ignition timing of methanol on the firing behavior and HC emission of the engine were studied by means of the cycle-by-cycle control technique. The results show that retarding the ignition timing from -20°（before top dead center） to 10° , results in more after-burning and the decrease in cylinder pressure gradually, and finally the engine fails to start. The optimal methanol engine ignition timing is -20°. If the fuel injection timing is controlled reasonably during the engine cold start, it is possible to ensure the most fuel-air mixture to enter into the cylinder on time,leading to ＂next cycle combustion after fuel injection＂ and high cold start reliability. The maximum cylinder pressure increases by 140° and HC emission decreases by 65% when the methanol injection timing changes from -35°to 471°（after top dead center, crank angle）.

关 键 词：甲醇发动机 冷起动 点火正时 喷射正时 循环控制 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]