不同燃烧模式的爆震特性及爆震强度评价方法  

Evaluation Method of Knock Characteristics and Knock Intensity in Different Combustion Modes

作　　者：王利民[1,2] 华剑雄 卫海桥 薛亮[1] 左俊杰[1] 李露梅[1] WANG Limin;HUA Jianxiong;WEI Haiqiao;XUE Liang;ZUO Junjie;LI Lumei(Guangxi Yuchai Co.,Ltd.,Yulin 537005,China;State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China)

机构地区：[1]广西玉柴机器股份有限公司,玉林537005 [2]天津大学内燃机燃烧学国家重点实验室,天津300072

出　　处：《内燃机工程》2021年第1期76-84,93,共10页Chinese Internal Combustion Engine Engineering

基　　金：国家自然科学基金项目(91641203);国家杰出青年科学基金项目(51825603)。

摘　　要：基于一台配备了全可变气门机构的单缸四冲程发动机开展了不同燃烧模式的燃烧和压力震荡特性研究,包括均质充量压燃(homogeneous charge compression ignition,HCCI)、汽油压燃(gasoline compression ignition,GCI)、湍流射流点火(turbulent jet ignition,TJI)和火花点火(spark ignition,SI)。研究结果表明:不同燃烧模式具有不同的统计学特征,其中HCCI、GCI和TJI的爆震强度分布较为集中,不易出现偶发的高爆震强度的燃烧循环;SI爆震的分布较为离散,通常具有较高的最大值和99%分位数,高爆震强度燃烧循环的偶发性较强;而低速早燃工况则是具有极高的爆震强度最大值和很低的99%分位数。此外,对于爆震工况的评价方面,对传统的算数平均值法和爆震循环占有率法进行了改进,提出了加权平均值法和破坏性循环均值法两种改进的爆震评价方法。二者在HCCI、GCI、TJI和SI爆震判定的准确性和适应性上相比改进前有了很大的提升;但对于低速早燃工况,破坏性循环均值法无法准确识别出其破坏性,加权平均值法具有非常好的准确性。A single-cylinder four-stroke engine equipped with variable valve actuating system was used to study the characteristics of combustion and pressure oscillation in different combustion modes,including homogeneous charge compression ignition(HCCI),gasoline compression ignition(GCI),turbulent jet ignition(TJI)and spark ignition(SI).Results show that different combustion modes have different statistical characteristics.Among them,the knock distribution in HCCI,GCI and TJI modes is relatively concentrated,rarely accompanied by occasional high knock intensity combustion cycles.But in SI mode,the knock distribution is relatively discrete,usually with higher maximum knock intensity and 99%quantile,as well as strong occasional high knock intensity combustion cycles,and also shows a very high maximum knock intensity and a very low 99%quantile under low-speed pre-ignition conditions.Moreover,in terms of the evaluation of knock conditions,based on the improvement of the traditional arithmetic average method and the knock cycle occupancy method,two new knock evaluation methods,the weighted average method and the destructive cyclic average method are proposed,so that the accuracy and adaptability of knock determination in HCCI,GCI,TJI and SI modes are greatly improved than before the improvement.But the use of destructive cyclic average method cannot accurately identify the destructiveness of knocking under low-speed pre-ignition conditions,while the weighted average method still has a very good effect.

关 键 词：燃烧模式 爆震燃烧 强度分布 爆震评价 

分 类 号：TK411.2[动力工程及工程热物理—动力机械及工程]