Through the comparative testing on the combustion and emission characteristics of diesel engine fueled with pure diesel and 20% and 40% ( volume fraction) gasoline blend fuels, the effects of fuel properties on the low temperature combustion in diesel engine are investigated. The results show that with the proportion of gaso-line increasing, ignition delay prolongs, especially at low oxygen concentration. This also leads to higher pressure rise rate and the shift of misfire limit toward higher low oxygen concentration, but for which advancing fuel injection timing may have certain compensation. Gasoline proportion has little effects on NOx , CO and THC emissions, but at low oxygen concentration range higher gasoline proportion can greatly reduce soot emission. When oxygen concentra-tion is lower than around 16% the emissions of CO and THC increase sharply and soot emission also enters the‘bump’ region, but advancing fuel injection timing can effectively lower their emission level;while it is just the op-posite for NOx , when oxygen concentration is higher than around 16 % its emission obviously rises and only retar-ding the injection timing can its emission improve.%通过对柴油机燃用纯柴油、20%和40%汽油(体积比)3种燃料时的燃烧和排放特性的对比试验,研究了燃料特性对柴油机低温燃烧的影响。结果表明,随着汽油比例的升高,滞燃期延长,低氧浓度时更加明显,这也导致了压升率的升高和“丢火”临界点向高氧浓度移动,但提前喷油时刻对此有一定补偿作用。汽油比例对NOx、CO和THC排放影响较小,但在低氧浓度区域,较大的汽油比例可以大幅降低碳烟排放。氧浓度大约低于16%以后,CO和TCH排放急剧上升；碳烟也进入高峰区,但提前喷油时刻可有效降低排放水平；而NOx 正好相反,氧浓度大约高于16%后,NOx 排放迅速升高,而只有延缓喷油时刻,才能改善其排放。
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