摘要
在经改装过的单缸发动机上进行了双燃料分层充质压缩着火(SCCI)燃烧的试验研究。分析了异辛烷作为预喷射燃料,柴油作为缸内直喷燃料的SCCI着火方式和燃烧过程,并固定异辛烷预喷射油量,研究不同柴油直喷当量比ΦD对SCCI燃烧的着火、燃烧和排放的影响。研究表明:双燃料SCCI燃烧是一种既包含扩散燃烧又包含预混合燃烧的复合燃烧形式,ΦD不仅决定了SCCI燃烧中柴油自身的燃烧情况,还决定了异辛烷的着火状况。在固定的异辛烷预喷射油量下,必然存在相应的最优柴油直喷当量比。该ΦD条件下柴油燃烧充分,且异辛烷的着火状况最好,异辛烷的燃烧过程最接近均质压燃;同时,发动机经济性提高,整体排放显著改善。随着给定的异辛烷当量比ΦP的增大,最优直喷当量比ΦD会逐渐减小。
Experiments on SCCI combustion of isooctane/diesel dual fuel were carried out with a single- cylinder modified engine. The ignition and combustion process of SCCI combustion of the pre-jet isooctane and the directly injected diesel oil was analyzed, and the influence of equivalence ratio of injected diesel oil （ФD） on combustion, ignition and emission of SCCI combustion was investigated when the isooctane amount （Фp） was fixed. The experimental results show that SCCI combustion of the dual fuel exhibits a compound combstion appearance including diffusive combustion and premixed combustion. ФD has an effect on the com- bustion of diesel oil and the ignition of isooctane. At any fixed value of isooctane amount（Фp）, there must be an optimal ФD. Under such a condition of optimal value, diesel oil burns completely, and isooctane is best ig- nited and its combustion process is the most similar to homogenous charge compression ignition. At this time, the fuel economy of the engine is increased, and the emissions are greatly improved. Furthermore, the optimal value of ФD decreases gradually with the increase of Фp.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2008年第5期1-6,共6页
Chinese Internal Combustion Engine Engineering
基金
国家"973"重点基础研究项目(2007CB210007)
上海市重大基础研究项目(05DJ14002)
