电容式多次放电点火系统设计与试验

针对某型二冲程点燃式空气辅助缸内直喷发动机燃用柴油问题,提出了实现单电容连续多次放电点火的方法,研制了直流电容式多次放电点火模块,进行了多次点火功能性验证及点火能量测试.在此基础上,进行了环境温度为6℃下的冷起动试验及3000r/min小负荷性能试验,结果表明:在该环境条件下,采用5次放电点火策略能够使发动机起动成功,在小负荷工况下,增加点火次数有利于改善缸内燃烧,点火提前角在10°~20°之间时,4次点火对发动机动力性、燃油消耗率及排放性能改善比2次点火更明显,当点火提前角提前至30°后,其改善作用逐渐减小. 

Design and experiment of multi spark capacitor discharge ignition system

A multi spark discharge ignition mode with a single capacitor for a two stroke air-assisted direct injection spark ignition engine fueled with diesel was proposed,and a direct current multi spark capacitor discharge ignition system was developed,in which the multi spark ignition mode was verified and ignition energies were tested.On these basis,the engine tests of cold start and low load at 3 000 r/min under 6 °C ambient temperature were conducted.The test results show that,applying 5 times capacitor discharge ignition is able to make a successful engine cold start,and under the low load condition,increasing the ignition times promotes the combustion in cylinder;4 times ignition is obviously more beneficial to improve the power performance,fuel economy and emissions performance than 2 times ignition with the ignition advance angle between 10° crank angle before top dead center and 20° rank angle before top dead center;the improvement effects gradually become small with the ignition timing angle advanced to 30° crank angle before top dead center.