在1台经过改装的1．99 L自然吸气缸内直喷点燃式甲醇发动机上，进行了喷嘴开启压力对发动机有效热效率、燃烧及排放影响的试验研究。在发动机转速为2000 r／min的各负荷工况下，选取7．5 M Pa ，12．5 M Pa和17．5 M Pa 3个喷嘴开启压力进行试验分析。结果表明：随着喷嘴开启压力的降低，发动机有效热效率、最大缸内压力和放热率略微增加，但是在小负荷工况下降低喷嘴开启压力，HC排放和CO排放显著增加，在大负荷工况下提高喷嘴开启压力会使NOx 排放显著增加。%On a retrofited 1 .99 L direct injection and naturally aspirated spark‐ignition (DISI) methanol engine ,the effects of injector opening pressure on engine effective thermal efficiency ,combustion and emission were researched .At different loads of 2 000 r/min ,the experiments of 7 .5 MPa ,12 .5 MPa and 17 .5 MPa injector opening pressure were conducted .The results show that the effective thermal efficiency ,maximum in‐cylinder pressure and heat release rate slightly increase ,but the HC and CO emissions will increase obviously at low load with the decrease of injector opening pressure .At high load ,the increasing opening pressure will lead to the obvious increase of NOx .
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