适用于天然气发动机高EGR率的引射器仿真研究  

Simulation Research on Ejector for Natural Gas Engine with High Exhaust Gas Recirculation Rate

作　　者：王晓艳 康天钦 王培伦 贾德民 徐煜 赵建辉[2] WANG Xiaoyan;KANG Tianqin;WANG Peilun;JIA Demin;XU Yu;ZHAO Jianhui(State Key Laboratory of Engine and Powertrain System,Weichai Power Co.,Ltd.,Weifang 261001,China;Institute of Power and Energy Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]潍柴动力股份有限公司内燃机可靠性国家重点实验室,山东潍坊261001 [2]哈尔滨工程大学动力与能源工程学院,黑龙江哈尔滨150001

出　　处：《西南交通大学学报》2024年第2期467-476,共10页Journal of Southwest Jiaotong University

摘　　要：针对发动机抑制爆震的难题,提出采用无功耗的引射器实现天然气发动机高废气再循环(EGR)率的技术方案.首先,完成设计工况下的引射器结构参数设计计算;然后,建立引射器仿真模型,并根据实验数据开展引射器计算模型的校核与验证;其次,对引射器引射性能随结构参数的改变进行分析,获取各结构参数对引射性能的影响规律;最后,提出了一种新的结构参数敏感性评价指标,研究了结构参数对引射性能的影响程度.研究结果表明:随着混合段长度和扩压段长度的增加,引射系数(μ)会随之增大;混合段直径(d_(3))、扩压段角度(θ_(s))和喷嘴出口至混合段距离(L_(NXP))的增加会导致μ先增加后减小,μ的最大值分别出现在d_(3)=46.1 mm、θ_(s)=4°和L_(NXP)=57.33 mm处;对μ影响最大的结构参数为d_(3),对应的敏感性指标为0.88,而L_(NXP)对μ的影响程度最小,敏感性指标为0.05.In view of engine knock,a technical solution was proposed to achieve a natural gas engine with a high exhaust gas recirculation(EGR)rate by utilizing a zero-power consumption ejector.Firstly,the structural parameters of the ejector were designed and calculated under specified operating conditions.Subsequently,the ejector simulation model was established,and the model was verified using experimental data.Furthermore,the ejection performance variations of the ejector with structural parameters were analyzed,and the influence of structural parameters on ejection performance was obtained.Lastly,a novel sensitivity evaluation index for structural parameters was introduced to examine the extent of their influence on ejection performance.The results show that as the length of the mixing section and the diffuser section increase,the entrainment coefficient(μ)increases.Conversely,as the diameter of the mixing section(d_(3)),the angle of the diffuser section(θ_(s)),and the distance from the nozzle outlet to the mixing section(L_(NXP))increase,μincreases first and then decreases.The maximum value ofμis observed at d_(3)=46.1 mm,θ_(s)=4°,and L_(NXP)=57.33 mm,respectively.Among the structural parameters,d_(3)exhibits the most significant influence onμ,with a corresponding sensitivity index of 0.88.However,L_(NXP)had the least impact onμ,with a sensitivity index of 0.05.

关 键 词：引射系数 敏感性分析 引射器 废气再循环 天然气发动机 

分 类 号：TK401[动力工程及工程热物理—动力机械及工程]