中文摘要：

本文就燃烧相位CA50对柴油机低温燃烧性能和排放的影响进行试验研究.结果表明,CA50在上止点附近时,指示热效率最高,燃油消耗率最低,但最大压力升高率也最高,工作粗暴.随着CA50的推迟,CO和碳烟的排放升高,THC和NOx排放降低.为满足更严格的排放标准,可在小EGR率时采取晚喷方式;大EGR率时采取早喷方式.为兼顾性能和排放,在本研究的工况下,最佳的CA50为上止点后4°CA.喷油控制策略主要取决于爆发压力的限制和对原始排放的要求,EGR和喷油策略共同决定燃烧相位CA50.

英文摘要：

An experimental study on the effects of combustion phasing CA50 on the low-temperature combustion performances and emissions of a diesel engine is conducted in this paper.The results show that when CA50 is close to TDC,the highest indicated thermal efficiency and the lowest specific fuel consumption are obtained,but the peak pressure rising rate also reaches the highest,leading to the harsh operation of engine.With the retard of CA50,the emissions of CO and soot increase while the emissions of THC and NOx fall.To meet more stringent emission regulation,it is recommended to delay fuel injection timing at smaller EGR rate while advancing it at larger EGR rate.With the tradeoff between performance and emission,4°CA ATDC is the optimum CA50 timing in the conditions of this study.Finally it is concluded that the strategy of fuel injection control mainly depends on the explosion pressure limit and the emission without after-treatment,and both EGR rate and fuel injection strategy determine the combustion phasing CA50.