双层喷油器锥角对双燃料发动机性能的影响  

Influence of spray angle of double⁃layer injector on performance in pilot⁃ignited natural gas engine

作　　者：王忠恕[1] 付晓东 王丹[1] 许允[1] 许瑞[1] WANG Zhong-shu;FU Xiao-dong;WANG Dan;XU Yun;XU Rui(State Key Laboratory of Automotive Simulation and Control,Jilin University,Changchun 130022,China)

机构地区：[1]吉林大学汽车仿真与控制国家重点实验室,长春130022

出　　处：《吉林大学学报（工学版）》2020年第3期842-849,共8页Journal of Jilin University:Engineering and Technology Edition

基　　金：国家自然科学基金项目(5167060226).

摘　　要：在一台6缸增压中冷重型柴油引燃天然气发动机上,试验研究了不同喷射参数下,不同规格的双层喷油器对燃烧、排放及经济性的影响。自行设计并加工了两种不同规格喷射锥角的双层喷油器,分别为双层142°锥角(喷油器1)和上层153°、下层119°锥角(喷油器2),分别与喷油时刻(17~31°CA BTDC)、喷油压力(70、140 MPa)相匹配,保持天然气能量替代率为90%,分析了转速为1656 r/min,25%负荷(B25工况)情况下两种喷油器对边界条件变化的敏感程度。结果表明:B25工况下,两喷油器对应的燃烧相位、热效率、排放随喷油时刻的变化规律与随喷油压力的变化规律基本相同;采用喷油器2可以获得更高的热效率和更低的THC排放,同时燃烧相位比喷油器1提前,着火延迟期和燃烧持续期也相对更短,燃烧速度更快;相对于70 MPa的喷油压力,采用140 MPa的喷油压力,仅使最佳喷油时刻延后,对热效率和排放的最优值影响不大。A 6-cylinder turbocharged intercooler heavy-duty pilot-ignited natural gas engine was used to study the influence of injectors with different spray angle on combustion,emissions and economy under different parameters.Two double-layer injectors with different spray angles were designed and processed,which are(1)double layer 142°angle(2)upper layer 153°angle and lower layer 119°angle.The natural gas percentage energy substitution rate is constant at 90%.Coupling with injection timing(17~31°CA BTDC)and injection pressure(70 MPa,140 MPa),the sensitivity of the two injectors to the change of boundary conditions is analyzed at 25%load,1656 rpm condition(B25).The results show that under B25 condition,the variation of the combustion phase,thermal efficiency and emission of the two injectors are basically the same on injection timing and injection pressure.The injector(2)can achieve higher thermal efficiency and lower THC emission,while combustion phase is earlier than the injector(1).Delay of ignition and duration of combustion are relatively shorter,and speed of combustion is faster. With injectionpressure of 140MPa compared to the injection pressure of 70MPa,only the optimal injection timing isdelayed,which has little effect on the optimal value of thermal efficiency and emissions.

关 键 词：动力机械工程 喷雾锥角 柴油引燃天然气发动机 喷射参数 燃烧相位 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]