缩口燃烧室中气流特性与燃油喷雾匹配对柴油机燃烧及排放的影响  

Effect of matching between airflow and fuel sprayin reentrant combustion chamber on combustion process and exhaust emissions

作　　者：袁方恩[1] 林学东[1] 田维[1] 高莹[1] 吴龙植 

机构地区：[1]吉林大学汽车动态模拟国家重点实验室,长春130022 [2]朝鲜平壤机械大学

出　　处：《吉林大学学报（工学版）》2011年第3期629-634,共6页Journal of Jilin University:Engineering and Technology Edition

基　　金：'863'国家高技术研究发展计划项目(2008AA110101)

摘　　要：利用三维数值仿真软件FIRE,对缩口直喷燃烧室内气流特性与燃油喷雾以不同喷射时刻匹配时对缸内速度场、浓度场和温度场分布特性的影响进行了仿真分析。研究了燃油喷雾与不同燃烧室空间气流特性匹配时的混合气形成特点和燃烧过程,并对混合气形成特点对发动机性能的影响进行了试验研究。结果表明,缩口燃烧室内气流特性与燃油喷雾以不同喷油正时匹配时,直接影响柴油机的预混合燃烧过程、扩散燃烧过程以及燃烧速率。结构一定的燃烧室内气流特性与燃油喷雾匹配时,存在最佳喷射时刻,不仅能够有效地调整预混合燃烧和扩散燃烧的比例,而且能够有效地控制燃烧放热率图形心的位置,有利于节能和排放控制。The effects of the matching between the airflow characteristic and the fuel spray in the reentrant combustion chamber of a direct injection diesel engine under different fuel injection timings on the fields of air velocity, air-fuel ratio, and temperature in the chamber were simulated using the 3-dimensional numerical simulation software FIRE. The behaviors of air-fuel mixture formation and combustion process under different conditions were studied and the effect of mixture formation on the engine performance was tested. The results showed that the matching between the airflow and the fuel spray under different fuel injection timings affects the premixed combustion phase, the diffusion combustion phase, and the combustion speed during the main combustion duration. For the matching of airflow and fuel spray in a given combustion chamber, there is an optimal fuel injection timing, which can adjust the proportions of premixed and diffusion combustion fuel quantities and the centroid crank angle position of heat release diagram, being of help for engine energy-saving and emission control.

关 键 词：动力机械工程 直喷柴油机 缩口燃烧室 气流特性 燃油喷雾 喷油正时 燃烧过程 排放 

分 类 号：TK421[动力工程及工程热物理—动力机械及工程]