重型发动机低负荷火花辅助汽油压燃试验  

Experiment of Spark-Assisted Gasoline Compression Ignition of Heavy-Duty Engine Under Low-Load Conditions

作　　者：李扬[1] 郑尊清[1] 陈鹏[1] 王梦凯 王浒[1] 尧命发[1] Li Yang;Zheng Zunqing;Chen Peng;Wang Mengkai;Wang Hu;Yao Mingfa(State Key Laboratory of Engines,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300350

出　　处：《内燃机学报》2022年第4期289-296,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(51976134).

摘　　要：通过一台由多缸柴油机改造的单缸重型发动机,研究了喷油时刻(SOI)、喷油压力和点火时刻(ST)对火花辅助汽油压燃(SAGCI)低负荷燃烧的影响.结果表明:喷油时刻与点火时刻合理配合对保证燃烧稳定性非常关键,在低负荷工况条件下,喷油时刻需在-34°~-20°CAATDC的范围内才能保证混合气被点燃,而点火时刻与喷油时刻控制为2°~18°CA的间隔才能保持良好的燃烧稳定性;提高喷油压力可以拓宽稳定燃烧的喷油和点火时刻范围,同时可以加速火焰传播过程,提高该边界下的指示热效率(ITE).在循环油量为33 mg下采用80 MPa喷油压力,此时CoV;=1.3%、压力升高率为0.2 MPa/(°)CA,火花辅助压燃燃烧效率达到96.7%,指示热效率为33.89%.An experiment was carried out on a single-cylinder heavy-duty testing engine modified from a multicylinder diesel engine to study the effect of start of injection(SOI),fuel injection pressure,and spark timing(ST)on spark-assisted gasoline compression ignition(SAGCI)for low-load operating conditions.Results show that the coordination of SOI and spark timing is critical for combustion stability.The SOI should be controlled within the range of-34°to-20°,CA ATDC to ignite the air-fuel mixture,and the interval of the spark timing and the SOI should be controlled between 2°—18°,CA to guarantee combustion stability.Increasing the fuel injection pressure helps to extend the span of SOI and spark timing for stable combustion,accelerate flame propagation,and improve the indicated thermal efficiency(ITE)under this condition.When adopting a fuel injection pressure of 80 MPa with a fuel consumption of 33 mg per cycle,the ITE of 33.89%and combustion efficiency of 96.7%can be achieved under the CoV;of 1.3%and the pressure rise rate of 0.2 MPa/(°),CA.

关 键 词：重型发动机 火花辅助汽油压燃 低负荷 喷油策略 点火策略 燃烧稳定性 

分 类 号：TK427[动力工程及工程热物理—动力机械及工程]