甲醇发动机的点火正时和喷射正时优选的试验研究

An Experimental investigation on Optimum of Ignition Timing and injection Timing in Methanol Engine

缸内喷射、火花助燃甲醇发动机是在缸内形成一种层状分布的不均匀混合气，为获得优良的燃烧和排放性能，存在一个最佳的点火和喷射正时。此时着火延迟期最短，缸内混合气浓、稀分布最合理，平均火焰传播速度最快，热效率最高，效率和排放折衷最好。本文详细介绍了点火正时和喷射正时的优选过程及对缸内混合气浓度分布及燃烧过程的影响。

In cylillder injected and spark-assisted methanol engine which can form a stratified distribution of non-uniform mixture has an optimum ignition and injection timing for obtaining good combustion and exhaust emissions performance. At that time ignition delay is the shortest, rich andlean mixture distribution in cylinder is the most reasonable, average flame propagation speed is thefastest, thermal efficiency is the highest. Compromise between efficiency and exhaust emissions isthe best.This paper presents in detail the optimum process of injection and ignition timing and the effects of injection and ignition timing on mixture concentration distribution in cylinder and combustion process.