轨压和EGR率对柴油机性能的影响

Effect of Rail and EGR-Ratio on Diesel Engine Performance

基于一台采用EGR+DOC+DPF+SCR(EGR为排气再循环系统;DOC为柴油机氧化型催化器;DPF为柴油机颗粒捕集器;SCR为选择性催化还原)技术路线的欧Ⅵ排放柴油机,研究轨压和EGR率对柴油机经济性的影响,其中经济性分析以综合油耗为指标,综合油耗包括油耗、尿素消耗和再生消耗的柴油。研究表明:随着轨压升高,NOx排放升高,碳烟(Soot)排放降低,柴油机有效燃油消耗率(break specific fuel consumption,BSFC)变好,综合油耗出现拐点;不同轨压变化时,EGR率对柴油机排放的影响变化一致,随着EGR率的升高,NOx排放降低,Soot排放升高,BSFC变差,综合油耗变好,当EGR率在18%左右时,综合油耗最佳。同时,与非EGR路线的欧Ⅴ柴油机进行经济性对比,EGR路线对BSFC有一定程度恶化,综合油耗并没有恶化。

Based on one EURO VI diesel engine which with the technology way is EGR ＋ DOC ＋ DPF ＋ SCR,the influence of the diesel engine emissions of the rail pressure and EGR-ratio were studied, the guidelines fot economic is the total consume which include BSFC AdBlue and the diesel of regeneration. The results showed that as the increase of rail pressure, the NOx emission would be getting higher, the PM emission would be getting lower and the BSFC would be getting better, but the total consume would turn at one operation point. When the rail pressux rechanges, the trend of the EGR-ratio is as same as the trend of the diesel engine emissions. As the increase of EGR-ratio, the NOx emission would be getting lower, the PM emission would be getting higher,and the BSFC would be getting worse, but the total consume would be getting better. When the EGR-ratio was 18%, the total economic was best of all. At the same time, compared with the economic of the EURO V diesel engine, it shows that the total consume of the EURO VI diesel engine gains an advantage over the EUROV diesel engine.