【摘要】 在一台单缸直喷柴油机上进行了二甲醚(DME)均质压燃(HCCI)燃烧过程的试验.研究结果表明,进气中加入30%的惰性气体CO2,发动机实现HCCI运转的负荷范围从0.05MPa扩展到0.35MPa.二甲醚在HCCI模式下表现出明显的双阶段着火特性,增加惰性气体的浓度,第一阶段着火始点滞后,燃烧放热峰值降低,燃烧持续期延长.排放测试表明,HCCI模式下发动机的NOx排放接近于零,可实现无碳烟排放,但CO和HC排放较高.更多还原

【Abstract】 Experimental study of homogeneous charge compression ignition（HCCI）combustion process is carried out on a single-cylinder direct injection diesel engine fueled with dimethyl ether （DME）.The research results indicates that the load range of HCCI engine can be extended from 0.05 MPa to 0.35 MPa when 30% CO₂ is inducted into the charging air. The HCCI combustion of DME presents remarkable character of two-stage combustion process. As the concentration of inert gas increases, the ignition timing of the first combustion stage delays, the peak of heat release rate decreases, and the combustion duration extends. Emission results show that under HCCI operation, a nearly zero NO_x emissions can be obtained while with no smoke emissions. But the HC and CO emissions are high.更多还原