提高化学计量比汽油机的燃油经济性及降低排放的研究

李维　 周龙保　 董英斌　

摘　要：提出了采用排气再循环同时提高压缩比的方法改善化学计量比汽油机的经济性、降低排放的新方法，并在单缸汽油机上进行了试验研究。试验中保持空燃比为化学计量空燃比，通过优化压缩比、涡流比及EGR率，发动机压缩比可以提高到11.8而不发生爆燃，燃油经济性提高5.3%，NO_x排放下降50%～60%，HC排放有所上升，但(NO_x＋HC)排放下降20%～30%。试验结果表明，采用该方法来改善化学计量比汽油机的性能是行之有效的。
关键词：汽油机； 化学计量空燃比； 压缩比； 排气再循环
分类号：TK413　文献标识码：A
文章编号：1000-0909（2001）02-0143-05

Research on Improving Fuel Economy and Lowing Emissions of Stoichiometric Engine

LI Wei（School of Energy and Power Engineering,Xi?an Jiaotong University,Xi?an 710049,China）　
ZHOU Long-bao（School of Energy and Power Engineering,Xi?an Jiaotong University,Xi?an 710049,China）　
DONG Ying-bin（School of Energy and Power Engineering,Xi?an Jiaotong University,Xi?an 710049,China）　

Abstract：In order to improve the fuel economy and reduce the emissions of stoichiometric engines,a new technical solution using heavier EGR and adopting higher compression ratio was proposed and carried out on a single cylinder engine.The air fuel ratio was kept at stoichiometric ratio in the experimental study.After inlet swirl ratios and EGR rates were optimized,the compression ratio could be raised to 11.8 without knocking combustion.The fuel economy was improved by 5.3%,NO_x and (NO_x＋HC) emissions were decreased by 50%～60% and 20%～30% respectively.The experimental results showed that the method is an effective way to improving the performance of stoichiometric engines.
Keywords：Spark ignition engine; Stoichiometric air-fuel ratio; Compression ratio; Exhaust gas recirculation

出版日期：2001年3月25日