车用多缸直喷柴油机燃用二甲醚的燃烧和排放特性研究(英文)

Investigation on Combustion and Emission Characteristic of a Multi-cylinder DI Diesel Engine Powered by DME

开展了4缸直喷柴油机燃用二甲醚时的燃烧和排放特性的研究。结果表明,适当增加喷油器伸出缸盖底平面的距离,采用流通截面较大的喷油器,降低启喷压力,可以提高CA498发动机燃用二甲醚时的热效率。燃用二甲醚时,发动机缸内的最大爆发压力和压力升高率低于燃用柴油时的情况。二甲醚发动机在所有工况下均可实现无碳烟排放,NOx排放约为柴油机的50%,CO和HC排放与柴油机相当。试验结果表明二甲醚是一种高效、低排放、燃烧噪声低的柴油机新型代用燃料。

Investigation on combustion and emission characteristic of a fourcylinder DI diesel engine fueled with DME is carried out. Experimental results prove thermal efficiency of CA498 engine with DME as fuel can be improved by appropriately increasing protruding distance of nozzle tip to the bottom plane of cylinder head, enlarging flowing area of nozzle and decreasing nozzle opening pressure. Compared with diesel, peak pressure and maximum rate of pressure rise are lower for DME operation. Smokeless combustion is realized for DME in all operating conditions. NOx emission of DME engine is about 50% of that of diesel engine. And HC and CO emissions are comparable to those of diesel engine. The new alternative fuel DME shows very promising results with respect to efficiency, emission and comfortable combustion noise.