【作者】 童来会； 尧命发； 郑尊清； 马帅营；

【Author】 (State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China)

【机构】 天津大学 内燃机燃烧学国家重点实验室；

【摘要】 在汽油/柴油双燃料高预混燃烧(HPCC)模式下研究了柴油两次喷射策略的二次喷油时刻对柴油机燃烧和排放特性的影响。结果表明:相对于柴油单次喷射的双峰放热特性,两次喷射策略燃烧则呈现较为明显的三峰状放热,因此主燃阶段放热速率降低,燃烧持续期变长,能够有效地推迟燃烧相位,降低最大压升率。排放方面,随着二次喷射时刻的推迟,NOx排放逐渐降低,而烟度则呈现出先升后降的趋势,在临界时刻点之前二次喷射时刻对HC和CO的影响较小。采用两次喷油策略通过对二次喷射时刻的优化,HPCC燃烧能够在较高的热效率的前提下实现较低的排放,显著降低最大压升率,有利于拓展负荷范围,并且保持较高的热效率。更多还原

【Abstract】 Experiments were carried out to investigate the effects of secondary injection timing on combustion and emissions of a gasoline/diesel dual fuel high premixed charge combustion(HPCC) engine with the diesel double injection strategy.The results revealed that the double injection strategy showed a three-stage combustion with a moderated burning rate and a much longer combustion duration which resulted in a delayed combustion phasing and reduced maximum rate of pressure rise.NO_x decreased with secondary injection timing delay while the smoke showed a two-bump trend.HC and CO emissions remain relatively flat before the critical point.The double injection strategy proposed showed that through further optimization of the secondary injection timing HPCC offers a good potential to expand the operating range while retaining a low emission level and acceptable engine efficiency.更多还原