气道喷射正庚烷缸内直喷异辛烷的分层充量压缩燃烧与排放特性  

An Experimental Study on the Combustion and Emissions Characteristics of Stratified Charge Compression Ignition Using Port-injection n-heptane and Direct-injection iso-octane

作　　者：周小鑫[1] 吕兴才[1] 吉丽斌[1] 黄震[1] 

机构地区：[1]上海交通大学动力机械及工程教育部重点实验室,上海200240

出　　处：《上海交通大学学报》2010年第10期1327-1331,1341,共6页Journal of Shanghai Jiaotong University

基　　金：国家自然科学基金资助项目(50976069)

摘　　要：在一台单缸发动机上,通过进气道预喷正庚烷和上止点前缸内直喷异辛烷,对双燃料分层充量压缩燃烧(Stratified Charge Compression Ignition,SCCI)进行了试验研究.通过进气道预喷的正庚烷在进气行程形成均匀混合气并在上止点前发生两阶段反应,触发缸内直喷的异辛烷着火与燃烧,整个燃烧过程为分阶段燃烧,分析了不同负荷及预混合率时的燃烧与排放特性.结果表明:最大压力升高率为0.87 MPa/(°)时,最大平均指示压力(I MEP)可达到0.73 MPa,说明SCCI可以扩展运行负荷.预喷燃油量最大时的工况点,其NOx排放值较高;预喷正庚烷燃空当量比一定时,增加负荷,可以减小CO和THC的排放.An experimental study was conducted on the combustion and emissions characteristics of dual-fuel SCCI on a single-cylinder engine,applying the port-injection n-heptane and in-cylinder direct injection iso-octane.Two-stage combustion of homogenous charge of n-heptane and air before top dead center ignites the iso-octane,so the SCCI could achieve a staged combustion.The effects of the load and premixed-ratio were explored.The test result shows that SCCI offers good potential to expand the operating range,because the value of IMEP is up to 0.73 MPa when the maximum pressure rise rate is 0.87 MPa/（°）.Operating points with high NO_x emissions have the most n-heptane amount of portinjection.Meanwhile,when the n-heptane amount of port-injection is fixed,increasing the iso-octane amount of direct injection can lower the CO and THC emissions.

关 键 词：分层充量压缩燃烧 正庚烷 异辛烷 排放特性 

分 类 号：TK16[动力工程及工程热物理—热能工程]