摘要
针对某重型天然气发动机各缸EGR率差别大、各缸最大燃烧压力差别大,影响发动机工作稳定性和可靠性,无法满足设计要求的问题,使用CFD方法对该发动机进行仿真分析。计算结果表明:进气总管中EGR波动导致进气时进入各缸的EGR率出现差异,因此各缸EGR率出现较大差异。根据计算分析提出了改进方案,将原有EGR取气引出的方式改为总管取气,并对进气腔和混合器间进气总管进行了重新设计,各缸EGR均匀性显著提高。试验验证表明,改进方案各缸最大燃烧压力差值减小,相对原方案有很大改善。
For the problem that the EGR rate and maximum combustion pressure in each cylinder of a heavyduty natural gas engine differentiate greatly so that the working stability and reliability of engine were affected and the design requirements cannot be met,the CFD simulation was carried out.The results showed that the EGR rate of each cylinder differentiates greatly due to the different EGR concentration of each cylinder resulted by EGR fluctuation in the intake pipe.An improved scheme was proposed based on the simulation analysis,in which the original EGR gas collecting method was modified to taking EGR gas from the intake pipe.Then the intake pipe between the inlet chamber and mixer was redesigned.Finally,the EGR uniformity of each cylinder significantly improved.The experimental results show that the difference between the maximum combustion pressures of each cylinder in the improved scheme decreases,which is much better than the original scheme.
作者
郭立新
李康宁
施东晓
刘阳
马立
GUO Lixin;LI Kangning;SHI Dongxiao;LIU Yang;MA Li(Wuxi Fuel Injection Equipment Research Institute,Wuxi 214063,China)
出处
《车用发动机》
北大核心
2019年第6期51-57,共7页
Vehicle Engine
