排气再循环下柴油引燃天然气发动机循环变动特性研究  

Cycle-by-Cycle Variations of a Diesel Pilot-Ignited Natural Gas Engine with Exhaust Gas Recirculation

作　　者：孙璐[1] 刘亦夫[1] 周磊[1] 曾科[1] 

机构地区：[1]西安交通大学内燃机研究所,西安701149

出　　处：《西安交通大学学报》2013年第3期36-41,共6页Journal of Xi'an Jiaotong University

基　　金：国家重点基础研究发展计划资助项目(2011CB707200)

摘　　要：在柴油引燃天然气发动机上开展了结合排气再循环(EGR)的循环变动特性研究,分析了不同EGR率和引燃油量下的循环变动规律。结果表明:在给定的引燃油量下,随着EGR率的增加,燃烧循环变动增强,缸内平均最大压力和平均指示压力下降,缸内最大压力和平均指示压力与缸内最大压力对应的曲轴转角之间的相关性减弱;引入EGR,缸内最大压力升高率减小,与曲轴转角之间的相关性减弱,燃烧速率下降;EGR率与循环变动系数呈非线性关系。输出扭矩不同,引燃油量对循环变动特性的影响不同,低负荷下过高和过低的引燃油量均会使得缸内平均指示压力循环变动加剧,负荷升高时引燃油量对循环变动系数的影响不太明显。Cycle-by-cycle variations of a pilot-ignited natural gas engine with EGR（exhaust gas recirculation） were examined. The effects of EGR ratio and pilot diesel quantity on cyclic variation characteristics were analyzed. The results show that when the cycle-by-cycle variations increase, the maximum average pressure decreases, and the indicated mean effective pressure decreases with an increase in the EGR ratio at a given pilot diesel quantity. Moreover, the weak interdependence occurs between the parameters above and their corresponding crank angles with an increase in the EGR ratio. The use of the EGR leads to the decrease in the burning rate and the maximum rate of pressure rise drops with the increase in the EGR ratio. The cycle-by-cycle variations change nonlinearly with the EGR ratio. At different loads, the pilot quantity has different influence on the cycle-by-cycle variations. Over-high or over-low pilot diesel quantity increases the cycle-by-cycle variations at the low load. The effect of the pilot quantity on the cycle-by-cycle variations is slight when the load is high.

关 键 词：发动机 柴油 天然气 引燃 循环变动 

分 类 号：TK474.7[动力工程及工程热物理—动力机械及工程]