电控LPG喷射发动机多次点火系统的研究

【作者】 栾亦木；

【导师】 何文华；

【作者基本信息】 浙江大学 ， 动力机械及工程， 2003， 硕士

【摘要】 近年来液化石油气(LPG)用作发动机代用燃料已经得到广泛的推广和应用，但同汽油相比，其着火温度高，传播速度慢，一般的汽油机点火系统无法满足要求。针对此问题，本文开发了一套基于微机控制的LPG喷射发动机多次点火系统。经过试验验证，该系统能可靠的实现点火提前角的优化和多次点火，对发动机动力性和排放的改善上也起到了一定的效果。 首先本文对电控LPG喷射发动机多次点火系统作了总体方案研究，相应选择了控制策略，最后在此基础上完成了系统硬件和软件的设计。整个控制系统是以PC机为核心控制单元的。 其次本文又对点火系统驱动电路的各种现有形式进行了分析，确定了电容放电式驱动电路的设计思路。经过多次摸索和试验，完成了点火驱动电路的设计。 最后作者利用本文研制的系统对170F发动机做了验证试验，结果表明：该点火系统能可靠的实现点火时刻的优化和调整多次点火，对发动机排放和动力性的改善起到了较好的作用。更多还原

【Abstract】 Recently, liquefied petroleum gas (LPG) has been applied widely as engine’s alternative fuel. But compared with gasoline, it has higher ignition temperature and lower flame spreading velocity. Normal gasoline engine’s ignition system could not meet LPG engine’s ignition demand. So, this paper exploited a multiple times ignition system based on PC controlled LPG injection. Through experiment, we found this system can reliably realize the optimization of ignition timing and multiple times ignition. It also has obvious effects on the improvement of LPG engine’s performance and emission.First, this paper studied the overall scheme of electronically controlled LPG injection engine’s multiple times ignition system. According to this scheme, the open-loop control strategy was chosen. Then, the hardware and software of this system were designed. The whole system’s central control unit is PC.Secondly, this paper analyzed the formats of ignition system driving circuitry, ensured the design thought of capacitance discharged driving circuitry. After times grope and experimentation, the design of ignition driving circuitry was accomplished.At last, the author did an experiment on 170F engine with the exploited system. The result indicated: This ignition system can reliably realize the optimization of ignition timing and the adjustment of multiple times ignition. It has a good effect on the improvement of engine’s emission and performance.更多还原