天然气缸内直喷发动机燃烧循环变动特性研究  

Study on Cycle-by-Cycle Variations in a Direct Injection Natural Gas Engine

作　　者：刘亮欣[1] 黄佐华[1] 蒋德明[1] 任毅[1] 王倩[1] 

机构地区：[1]西安交通大学动力工程多相流国家重点实验室,陕西西安710049

出　　处：《内燃机学报》2005年第1期18-27,共10页Transactions of Csice

基　　金：国家自然科学基金杰出青年资助项目(59925617);国家自然科学基金项目(50422261);优秀国家重点实验室研究项目(50323001)。

摘　　要：开展了天然气高压缸内直喷发动机的燃烧循环变动特性研究。研究结果表明,小当量比工况下(<0.4),会出现失火循环和部分燃烧循环,平均指示压力pmi值低,pmi的循环变动系数大,大当量比工况下pmi的循环变动系数小。最高气缸压力高的循环燃烧速率快、燃烧过程的等容度好。最高气缸压力与其对应的曲轴转角之间、最高气缸压力升高率与其对应的曲轴转角之间、最高气缸压力和pmi之间都存在着一定关系。最高气缸压力与火焰发展期、快速燃烧期也存在很好的对应关系。高的最高气缸压力对应着短的火焰发展期和短的快速燃烧期。循环的累积放热量越大则pmi越大,pmi的大小与累积放热量的大小存在对应关系。In this paper,the cycle-by-cycle variations in a direct injection natural gas engine were investigated.The results show that there exist the misfire cycles and the partial burn cycles when operating on the small equivalence ratio conditions(<0.4).Meanwhile,the indicated mean effective pressure(p_(mi))gives low value while the coefficient of variation of p_(mi) is higher compared to that operating on the large equivalence ratio.High maximum cylinder pressure(p_(max)) cycles correspond to the fast burning cycles.Interdependencies exist between the maximum cylinder pressure and its corresponding crank angle,the maximum rate of pressure rise and its corresponding crank angle,the maximum cylinder pressure and the indicated mean effective pressure.Furthermore,better interdependencies also exist between the maximum cylinder pressure and the flame developing period,between the maximum cylinder pressure and the rapid burning period.High p_(max) corresponds to short flame developing period and short rapid burning period.The value of p_(mi) is found to be related to the accumulated heat release in a cycle.

关 键 词：天然气 循环变动 缸内直喷 发动机 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]