直喷柴油机燃用二甲醚的试验研究

在直接喷射式柴油机上进行了燃用二甲醚的试验研究，对柱塞有效行程和柱塞直径、供油提前角、喷油压力、进气涡流比、喷嘴型式等燃烧系统主要参数对发动机功率和热效率的影响进行了研究，在燃料供给系统中增加燃油输送泵，消除了气阻，发动机可以在宽广的转速和负荷范围内稳定运行，发动机热效率比原机高３％ 。在优化燃烧系统参数的基础上对示功图和排放的测量及计算表明：二甲醚发动机最高爆发压力、最大压力升高率和 Ｎ Ｏｘ 排放均低于原机，烟度排放为０。试验结果显示了直喷式柴油机燃用二甲醚在降低排放方面的优越性能。

Investigation of a Direct Injection Diesel Engine Fueled with Dimethyl Ether

The paper presents the research results of a direct injection diesel engine operating on dimethyl ether (DME).The effects of main parameters of combustion system such as plunger diameter,nozzle type,fuel delivery advance angle,protruding distance of nozzle tip to the bottom plane of cylinder head and swirl ratio on performances of DME engine are investigated.By adding a pressure pump in the fuel supply system,the vapor block of DME in the fuel system is eliminated,and the engine runs smoothly on DME over the wide range of speeds and loads.The indicator diagrams and emissions are recorded and calculated after optimization of the combustion system and compared with those of the engine operating on diesel.The thermal efficiency of DME engine shows 3% higher than that of diesel engine and low maximum combustion pressure,low rate of pressure rise,smokeless combustion,low NO x emissions can be achieved.The results show some excellent characteristics in reducing emissions for diesel engine operating on DME.