In order to analyze the effect of the double-spark plug ignition (DSI) on the heat release rate, cyclic variation in combustion and engine knocking, four different single- and double-spark plug ignition strategies are used for testing. Combustion diagnosis results show that when the DSI strategy is used, it can effectively promote the combustion process, increase the maximum combustion pressure, shorten the combustion duration and reduce the coefficient of cyclic variation (COV). Under low load condition, the effects are more pronounced. Test data reveals the following phenomenon. With the DSI strategy, both the cyclic variation in the early period of rapid-burning and in the later period of rapid-burning are reduced, especially in the early period of rapid-burning. Then, the cyclic variation rate of the combustion duration is significantly reduced. Since the burning rate in the early period of rapid-burning is greatly accelerated, knocking tendency of the DSI engine is more obvious than that of the single-spark SI engine. The potential to improve engine performance and fuel economy by the DSI strategy largely depends on the optimization of the spark advance. Based on the optimization of the ignition timing of the DSI strategy S_28&28, the break mean effective pressure (BMEP) is improved by about 5%-6% compared to the original 158FMI engine.

为了分析双火花塞点火（DSI）对放热率，燃烧和发动机爆震的周期性变化的影响，我们使用了四种不同的单火花塞和双火花塞点火策略进行测试。燃烧诊断结果表明，采用DSI策略可有效促进燃烧过程，增加最大燃烧压力，缩短燃烧持续时间，减小循环变异系数（COV）。在低负载条件下，影响更为明显。测试数据显示以下现象。使用DSI策略，可以减少快速燃烧早期和快速燃烧后期的周期性变化，特别是在快速燃烧早期。然后，燃烧持续时间的周期性变化率显着降低。由于快速燃烧早期的燃烧速度大大加快，因此DSI发动机的爆震趋势比单火花SI发动机的爆震趋势更加明显。通过DSI策略提高发动机性能和燃油经济性的潜力在很大程度上取决于火花提前的优化。基于DSI策略S点火正时的优化_{如图28和28所示}，与原始158FMI发动机相比，制动平均有效压力（BMEP）提高了大约5％-6％。