GDI喷油器积碳对尾喷现象的影响  

Effect of GDI engine injector coking on secondary injection spray

作　　者：裴毅强[1] 王志东[1] 周建伟[1] 王莉 张延峰[1] 郭瑞涛 PEI Yiqiang;WANG Zhidong;ZHOU Jianwei;WANG Li;ZHANG Yanfeng;GUO Ruitao(State Key Laboratory of Engines,Tianjin University,Tianjin 300072,China;College of Engineering and Technology,Tianjin Agricultural University,Tianjin 300384,China)

机构地区：[1]天津大学内燃机燃烧学国家重点实验室,天津300027 [2]天津农学院工程技术学院,天津300384

出　　处：《哈尔滨工程大学学报》2018年第10期1633-1639,共7页Journal of Harbin Engineering University

基　　金：国家自然科学基金项目(51306132)

摘　　要：为了研究缸内直喷(GDI)发动机喷油器积碳对尾喷现象的影响,利用高速摄像机对GDI喷油器喷雾图像进行近场拍摄。对比清洁喷油器和积碳喷油器在不同喷射压力下的尾喷图像,结果表明:随喷油压力增加,尾喷起始时刻提前,尾喷贯穿距和尾喷贯穿速度略有增加,但对尾喷持续期影响较小;积碳会改变喷孔的有效面积,增加喷孔附近的粗糙度,对尾喷油束起阻碍和吸附作用,导致尾喷起始时刻滞后,尾喷持续期缩短,并使尾喷油束的贯穿距和速度减小。在常温下,尾喷现象属于第二类风生破碎形式。To study the effect of gasoline direct injection(GDI)engine injector deposits on the secondary injection,a high-speed camera was used to conduct near-field recording of the GDI injector′s spray image.The secondary injection images of new versus coking injectors were compared under different injection pressures.The results revealed that increasing injection pressure tended to accelerate the start-up moment of secondary injection.Penetration distance and spray velocity increased slightly,but had little influence on the duration of secondary injection.Deposits were shown to(1)change the effective orifice area,(2)increase the roughness of the area near the nozzle,(3)block and adsorb the secondary injection fuel,delaying the start-up moment of secondary injection,(4)shorten the duration of secondary injection,and(5)reduce the penetration distance and spray velocity.The secondary injection phenomenon was shown to belong to the second wind-induced breakup regime at normal temperature.

关 键 词：直喷汽油机 喷油器积碳 尾喷现象 雾化特性 多孔喷油器 尾喷贯穿距 破碎类型 米散技术 

分 类 号：TK413.8[动力工程及工程热物理—动力机械及工程]