摘要
以某小型非道路电控柴油机为样机,采用峰排气凸轮实现内部废气再循环(Internal Exhaust Gas Recirculation,IEGR),通过数值模拟计算和试验研究,分析IEGR小型非道路电控柴油机的排放性能。结果表明:设计的双峰排气凸轮方案能有效实现IEGR率。排气副凸轮开启始点推迟,能使IEGR率明显降低,燃油消耗率及功率分别有微弱的下降和上升;排气副凸轮升程的增加,使IEGR率及燃油消耗率都有微弱的上升,功率略微下降;排气副凸轮工作段包角的增加,使IEGR率略微上升,油耗及功率变化甚微。IEGR结合电控喷油正时的协同优化,当IEGR方案的HC+NOx加权排放值由原机的6.722g/h降低至5.161g/h时,碳烟排放及CO排放在满足美国EPAⅣ非道路排放法规的基础上有略微增加;当IEGR方案HC+NOx加权排放值与原机相当时,燃油消耗率降低了4.2%,CO排放降低了30.7%,而碳烟排放仅微弱上升。IEGR结合电控喷油正时的协同优化具有实现整机性能优化的潜力,为IEGR技术在小型非道路柴油机上的应用提供了参考。
Taking one Small-size off-road electronically controlled diesel engine as the research object,a method of double-peak exhaust cam is adopted to achieve internal exhaust gas recirculation(IEGR).The emission performance study on the influence of IEGR on small off-road electronically controlled diesel engine is analyzed through numerical simulation and experiment.The results indicate that the design scheme of double-peak exhaust cam can achieve IEGR rate effectively.When the open starting point of exhaust little cam is delayed,IEGR rate is reduced significantly,fuel consumption rate and power have a slight decline and rise.When the lift of exhaust little cam is increased,IEGR rate and fuel consumption rate all increased slightly while power decreases slightly.When the durable angle of exhaust little cam is increased,IEGR rate increases slightly while fuel consumption and power changes little.Collaborative optimization of IEGR combined with electronically controlled fuel injection timing.When the weighted emission of HC+NOx of IEGR scheme decreased from 6.722g/h in target diesel to 5.161g/h,soot and CO emissions slightly increased but still meet the off-road emission regulations of EPAⅣ.When the weighted emission of HC+NOx of IEGR scheme is about the same as target diesel,fuel consumption decreases by 4.2%,CO emissions decreases by 30.7%,while soot emissions rise only marginally.Therefore,it is validated that collaborative optimization of IEGR combined with electronically controlled fuel injection timing has the potential to improve engine performance comprehensively and the present work can provide theoretical basis for the application of IEGR on small-sized off-road diesel engine.
作者
孙旭晨
贾和坤
刘志远
SUN Xu-chen;JIA He-kun;LIU Zhi-yuan(School of Automotive and Traffic Engineering,Jiangsu University,Jiangsu Zhenjiang 212013,China)
出处
《机械设计与制造》
北大核心
2018年第A02期22-26,共5页
Machinery Design & Manufacture
基金
江苏省自然科学基金(青年)项目(BK20150520)
