双线圈点火系统特性仿真与试验研究

摘要

为了降低稀燃CNG发动机燃烧循环变动，设计了一种双线圈点火系统。利用Multisim软件仿真研究了新点火系统次级电压的变化规律，并在发动机台架上研究了此点火系统对CNG发动机燃烧稳定性的影响。次级电压的仿真结果表明，在不同放电间隔的条件下，新点火系统分别能够有效提高次级电压，增加火花持续期并能实现多次放电。台架试验表明，在合适的放电模式下新点火系统能够降低发动机的循环变动系数，提高稀燃CNG发动机燃烧稳定性。%In order to reduce cyclic variation, a dual-coil ignition system for a CNG engine was proposed in this pa-per. Using Multisim software, the change rule of secondary voltage of the new ignition system was studied. The im-pact of this ignition system on combustion stability of the CNG engine was studied on the engine test bench. Experi-mental results of secondary voltage show that compared with single-coil ignition, the new ignition system can effec-tively increase secondary voltage, extend spark duration and achieve multiple discharges under different discharge interval conditions. Bench test shows that, in a suitable discharging mode, this system can reduce the probability of misfire and the cyclic variation coefficient of CNG engine, consequently it improves the combustion stability of lean burn CNG engine.