摘要
在1台搭载了均质稀薄燃烧系统的光学单缸发动机上,对比了常规点火系统和其他两种点火能量可调的持续放电式高能点火系统,通过燃烧分析和高速摄影等技术手段,研究了稀燃条件下影响高能点火效用的一些关键因素。结果表明:对于持续放电式高能点火系统,提升放电功率是提高点火能量利用率并提升燃烧稳定性最为有效的措施;因跟高能点火有效放电时间密切相关的燃烧持续期相对较长,低速、小负荷时高能点火系统的能量利用率最高,燃烧更快、稳定性更好,同时稀燃极限的提升效果也较为明显;此外,火花塞电极形式和电极方向也对稀燃-高能点火系统有着一定的影响,双针火花塞、适当加大的电极间隙和背对进气门方向的电极间隙布置,均有利于电弧和初始火核的形成,在稀燃条件下燃烧更快更稳定。
The crucial factors of high-energy ignition applied on homogeneous lean-burn gasoline engine were investigated on an optical single-cylinder engine.A conventional ignition system and two other high-energy ignition systems with variable energy and continuous discharge were compared by means of combustion analysis and high speed photography.The experimental results indicate that boosting the spark discharge power level is the most effective way to enhance ignition energy and improve combustion stability.Meanwhile,the utilization rate of high-energy ignition system is higher at low speed and low load due to longer combustion duration,which results in a faster and more stable combustion process and an extra extended lean-burn limit.Besides,since the spark plug type and orientation also influence the formation of spark channel and the development of early flame,a pin-to-pin spark plug with larger electrode spacing and spark plug with electrode gap back to the intake side are suggested,which can improve the combustion velocity and stability.
作者
吴锡江
王志宇
尹琪
WU Xijiang;WANG Zhiyu;YIN Qi(SAIC Motor Technical Center,Shanghai 201804,China)
出处
《车用发动机》
北大核心
2020年第5期1-10,72,共11页
Vehicle Engine
关键词
汽油机
稀薄燃烧
高能点火
电流通道
燃烧稳定性
稀燃极限
gasoline engine
lean burn
high-energy ignition
spark channel
combustion stability
lean-burn limit
