进气门早关对柴油机燃烧循环变动特性的影响  

Effects of Early Intake Valve Closing on Characteristics of Cyclic Variations in Diesel Engine

作　　者：张炯[1,2] 常英杰[1,2] 谢宗法[1,2] 闫帅[1,2] 王兆宇 Zhang Jiong Chang Yingjie Xie Zongfa Yan Shuai Wang Zhaoyu(School of Mechanical Engineering, Shandong University, Jinan 250061, China Key Laboratory of High Efficiency and Clean Mechanical Manufacture of Ministry of Education, Shandong University, Jinan 250061, China Longkou Zhongyu Machinery Company Limited, Yantai 265700, China)

机构地区：[1]山东大学机械工程学院,山东济南250061 [2]山东大学高效洁净机械制造教育部重点实验室,山东济南250061 [3]龙口中宇机械有限公司,山东烟台265700

出　　处：《内燃机学报》2016年第5期401-408,共8页Transactions of Csice

基　　金：国家重点基础研究发展计划(973计划)资助项目(2013CB228404);国家自然科学基金资助项目(51375265)

摘　　要：在SD2100型柴油机上安装全可变液压气门机构,采用进气门早关(EIVC)的模式可实现进气门关闭时刻(IVC)和有效压缩比(ECR)的连续可变.结果表明:随着IVC提前,ECR降低,燃烧始点推迟,最高燃烧压力降低,最高燃烧压力对应的曲轴转角推后;当ECR为13时,出现最大燃烧压力低于上止点压缩压力的现象,甚至出现不正常燃烧循环,导致燃烧循环变动率显著增大;增压匹配EIVC降低爆发压力和燃烧温度时也会出现燃烧循环变动增大的趋势;在相同的IVC条件下,过量空气系数越大,混合气浓度越低,燃烧循环变动率也越大.进一步研究表明,EIVC导致的燃烧循环变动问题与燃烧发展期Δφ密切相关,Δφ越长,燃烧重心CA 50越偏离上止点,燃烧循环变动率越大;根据Δφ的增大量,适当增大供油提前角,可显著降低燃烧循环变动率,提高指示热效率.A fully hydraulic variable valve actuation using early intake valve closing （EIVC）mode was mounted on a SD2100 diesel engine. Intake valve closing （IVC） and effective compression ratio （ECR） can be continuously var- ied. Experimental results show that, with the advance of IVC, ECR is decreased, start of combustion is delayed, peak pressure is decreased and its corresponding crank angle is delayed. When ECR decreases to 13, the maximum combustion pressure is lower than that of the motored peak pressure and abnormal combustion cycles widely appear, leading to larger cyclic variations. Combination of boost and EIVC to make low combustion temperature and peak pressure also brings higher cyclic variations. At the same IVC, cyclic variations increase with the increase of excess air ratio because of low fuel concentration. Study also shows that the cyclic variations caused by EIVC give strong correlation with the early combustion duration, larger early combustion duration makes away of the center of heat release （CA 50） from the TDC, leading to large cyclic variations. Advancing the fuel supply angle can reduce cyclic variations and improve indicated thermal efficiency.

关 键 词：柴油机 进气门早关 可变有效压缩比 燃烧循环变动 

分 类 号：TK421.2[动力工程及工程热物理—动力机械及工程]