高效低排放柴油机喷油器喷嘴几何结构研究  

Study on Nozzle Geometric Structure of a High-Efficiency and Low-Emission Diesel Engine

作　　者：班智博[1] 官维 赵华[2] 林铁坚[1] 潘明章[3] Ban Zhibo;Guan Wei;Zhao Hua;Lin Tiejian;Pan Mingzhang(Guangxi Yuchai Machinery Company Limited,Nanning 530004,China;College of Engineering,Design and Physical Sciences,Brunel University,London UB83PH,UK;College of Mechanical Engineering,Guangxi University,Nanning 530004,China)

机构地区：[1]广西玉柴机器股份有限公司,广西南宁530004 [2]布鲁内尔大学工程设计和物理科学学院,英国伦敦UB83PH [3]广西大学机械工程学院,广西南宁530004

出　　处：《内燃机学报》2023年第3期230-237,共8页Transactions of Csice

基　　金：国家自然科学基金资助项目(22172038,52066003);广西高效节能环保内燃机重点实验室资助项目(19-185-1).

摘　　要：研究了喷油器喷孔形状、喷孔流量和喷雾锥角对发动机燃烧及性能的影响.结果表明:锥形喷孔(Ks形状)的喷油器具有较高的流量系数和较长的贯穿距,能够改善柴油机的雾化质量,从而提高指示热效率并降低颗粒物排放;同时,相对较长的燃油贯穿距和较短的喷射持续期在发动机高负荷时的作用更为显著.喷油器垫圈厚度(喷嘴凸出高度)对油束在燃烧室中的合理分布影响很大,喷雾锥角越大,为达到最佳性能需要的垫圈越薄,反之亦然.最后,对发动机的整体效率进行了分析,结果表明:喷雾锥角为146°的喷油器与厚度为2.0 mm的垫圈组合,在保持较高发动机效率的同时,能够实现最低的发动机NOx排放,降低选择性催化还原(SCR)系统中的尿素消耗,实现最低的总液体消耗量,从而降低发动机的总运行成本.Effects of nozzle hole geometry,fuel mass flow rate and spray cone angle on combustion,performance and emissions were experimentally examined on a diesel engine for high efficiency and low emissions.Results shows that the injector nozzle with Ks-hole shape improves fuel atomization quality due to higher discharge coefficient and longer spray tip penetration.This results in an increase in fuel conversion efficiency and a decrease in soot emissions.Compared to the injector nozzle with lower fuel mass flow rate,the nozzle with higher mass flow rate increases the fuel conversion efficiency attributed to relatively longer fuel penetration and shorter injection duration,especially at high engine loads.The thickness of the injector washer(e.g.injector tip protrusion)also shows a strong effect on the interaction between the fuel spray and the combustion bowl.The bigger the spray cone angle is,the thinner the washer is required so as to achieve an optimal performance,and vice versa.In addition,an analysis of overall engine efficiency was carried out and the results show that the injector with a spray cone angle of 146°combined with a washer thickness of 2.0 mm achieves the lowest engine-out NOx emissions while maintaining higher engine efficiency.This decreases the urea consumption in the selective catalytic reduction(SCR)system and thus leads to a lower total fluid consumption which potentially minimizes the total engine operation cost.

关 键 词：重型柴油机 喷嘴形状 喷嘴直径 喷雾锥角 总液体消耗 

分 类 号：TK423[动力工程及工程热物理—动力机械及工程]