EGR对车用柴油机性能影响的试验研究

结合某废气涡轮增压和高压共轨小型4缸柴油机国Ⅳ排放达标工作,进行了计算机在线实时控制EGR对柴油机性能影响的试验研究,通过试验分析了EGR对NOx、烟度、排气温度、燃油消耗率的影响规律,并对EGR率与喷油提前角的匹配作了进一步的研究。结果表明,为降低柴油机NOx排放,不同工况应采取不同的EGR率;烟度、排气温度、燃油消耗率均随着EGR率的增加而增大;EGR率和喷油提前角应实现良好的匹配,才能保证NOx排放和燃油消耗率都能达到要求,其中小EGR率匹配小喷油提前角,大EGR率匹配大喷油提前角。

Influence of EGR on Vehicle Diesel Engine Performance

Based on the requirement of Stage Ⅳ emission for a small type 4-cylinder diesel engine with exhaust gas turbocharging and high-pressure common rail system,the influence of computer real-time control for EGR on diesel engine performance was researched.By the experiment,the influence of EGR on NOx emission,smoke,exhaust temperature and fuel consumption rate were analyzed,and then the EGR rate and advance angle of injection matching were further researched.The results show that different EGR rates under different operating conditions help to reduce the NOx emission.With the increase of EGR rate,the smoke,exhaust temperature and fuel consumption rate increase.In addition,the EGR rate and advance angle of injection should match well to ensure that the NOx emissions and fuel consumption rate can meet the requirements.That is,low EGR rate should match small advance angle of injection and high EGR rate should match large advance angle of injection.