中文摘要：

针对柴油机瞬态工况排放黑烟的现象，采用同步往进气道喷甲醇加以抑制的方法进行了研究。为此开发了一套根据发动机工况变化的甲醇喷射的电控系统。在一台高速非增压直喷柴油机上对进气喷甲醇和纯柴油的瞬态烟度排放两种情况进行了试验对比研究。结果表明，以城市公交车的起步加速和加载加速工况以及发动机高低转速下的增转矩瞬态工况为对象，进气喷甲醇的方法可以减少烟度排放达到50％以上，说明采用进气喷甲醇为柴油机解决冒黑烟问题提供了一种技术途径。

英文摘要：

In this study, methanol injection at intake port to suppress the smoke of diesel engine under transient operation conditions is investigated. An electronic control system was developed to control the methanol injection based on engine mode variation. Comparative study was conducted on a naturally injected aspirated high speed D.I. diesel engine to investigate the effects of diesel and methanol injection on the smoke. Experimental results show that methanol injection can decrease the smoke opacity of city bus by more than 50% under the transient modes of start-up acceleration and load/speed increasing. Methanol injection at intake port provides a new approach to decrease the smoke of diesel engine.