中文摘要：

为探索二甲醚／柴油混合燃料作为柴油机替代燃料的应用性能，对D20二甲醚／柴油混合燃料的喷雾特性进行了试验研究；同时，开展了直喷式柴油机燃用二甲醚／柴油混合燃料动力性能、经济性能及排放性能研究。结果表明：在同样的环境背压下，D20混合燃料的油柬与柴油相比较，贯穿度有所缩短，喷雾锥角有所增大；柴油机燃用二甲醚／柴油混合燃料时，通过适当调整循环油量，发动机的动力性可以超过原柴油机，最低当量比油耗下降4．5％，烟度指标下降70％以上，NO，排放降低30％～50％；二甲醚／柴油混合燃料是一种能实现高比功率、低排放的石油替代燃料。

英文摘要：

In order to study performance of application of dimethyl ether/diesel （DME/diesel） blended fuel instead of ignition engine fuel, an investigation was carried out to determine spray characteristics of D20 blends. The power performance, fuel economy and emission properties of direct injection diesel engine were studied. Results show that under same ambient pressure, D20 fuel exhibits the shorter spray penetration and the larger spray angle compared with diesel. Through adapting cycle oil consumption, power performance of engine can be improved, such as a 4.5% reduction in the lowest fuel specific consumption rate, a decrease of more than 70%/60 in soot emission indexes, and a 30% to 50% decrease in NOx emissions. Thus, DME/diesel blended fuels can realize high power output and low exhaust emissions for the engine.