基于内窥镜的汽油发动机喷水可视化研究  

Visualization Study on Water Injection of Gasoline Engine Based on Endoscope

作　　者：郭涛[1] 李相超[1] 张弘[1] 尹琪[1] 杨磊[1] 林长林 GUO Tao;LI Xiangchao;ZHANG Hong;YIN Qi;YANG Lei;LIN Changlin(SAIC Motor Technical Center,Shanghai 201804,China)

机构地区：[1]上海汽车集团股份有限公司技术中心,上海201804

出　　处：《车用发动机》2020年第3期71-75,共5页Vehicle Engine

摘　　要：设计了高速内窥镜系统,对汽油发动机进气道内的水雾喷射过程进行了可视化研究。对比了两种喷水器布置、不同喷水时刻和不同喷水压力下的水雾喷射过程,并结合台架数据分析了这些因素对发动机燃油消耗率和NO x排放的影响。结果表明,在3000 r/min@1.4 MPa工况下,使用3∶10的水油质量比,发动机喷水后燃油消耗率降低约3%,NO x排放降低约20%。喷水器结构和布置方案对喷水效果影响不大。喷水时刻影响水雾进入缸内蒸发冷却的过程,不同喷水时刻下发动机燃油消耗率略有差异,NO x排放变化趋势与燃油消耗率相反。喷水压力影响水滴雾化和运动过程,高喷射压力下雾化变好,但会使水滴在进气道内提前蒸发,反而降低其对缸内的冷却效果,试验在0.8 MPa喷射压力下燃油消耗率最低,而NO x排放随着喷射压力的升高逐步降低。High-speed endoscope system was designed to visualize the water injection process in the intake port of gasoline engine.The water injection processes were compared under two water injector layouts,different injection timings and injection pressures and the effects of these factors on fuel consumption and NO x emission were further analyzed by combining bench test data.The results showed that using 3∶10 water-gasoline mass ratio at the point of 3000 r/min and 1.4 MPa could lead to 3%decrease of fuel consumption and 20%reduction of NO x emission.The effects of water injection would hardly change for different injectors and layouts.The water injection timing affected the evaporation and cooling process after the water spray entered the cylinder.Under different injection timings,the differences of specific fuel consumption between them were little and NO x emission showed an opposite trend with it.In addition,injection pressure affected water spray atomization and movement.Higher injection pressure could produce a better effect of atomization,but lead to an earlier evaporation of water droplets in intake port that was not helpful to the in-cylinder cooling.It was finally found that the optimal fuel consumption could be achieved at the injection pressure of 0.8 MPa where NO x emissions gradually reduced as the injection pressure increased.

关 键 词：喷水 汽油机 可视化 

分 类 号：TK413.84[动力工程及工程热物理—动力机械及工程]