二甲醚均质压燃、柴油补燃混合燃烧模式的试验研究

Experimental Investigation of Hybrid Combustion System with DME HCCI and Diesel Fuel Injection in a DI Diesel Engine

在一台4102直喷柴油机上研究了二甲醚(DME)均质压燃,柴油补燃混合燃烧模式对发动机性能、排放、油耗和燃烧特性的影响。试验结果表明,采用混合燃烧模式能有效降低发动机的碳烟排放及低负荷区域的NOx排放,但在整个工作区域内发动机的当量燃油耗偏高。此外,通过燃烧分析发现,大部分负荷下采用混合燃烧模式的发动机气缸最高燃烧压力比采用纯柴油的高,但最大压力升高率和压力升高加速度却比较低,因此发动机运行比较柔和。

The performances, emissions, economies and combustion characteristics of a hybrid combustion system with dimethyl ether（DME） homogeneous charge compression ignition （HCCI） and diesel fuel injection were investigated on a 4102 direct injection diesel engine. It is found that DME and diesel fuel hybrid operation can effectively reduce engine smoke and light-load＇s NOx emissions, while the engine equivalence fuel consumption appears higher in its full range operation. It is also found through the combustion analysis that the engine cylinder maximum combustion pressure of hybrid operation is higher than that of straight diesel operation at most of engine loads, while the maximum rate of pressure rise, maximum acceleration of pressure rise are both lower, which suggests a smooth operation with hybrid combustion.