燃用不同标号汽油的发动机性能对比研究

Comparative Study on Performance of Engine with Different Grades Gasoline

为了探究不同标号的汽油对发动机性能的影响,在1台气道喷射(PFI)增压发动机上分别燃用92#和95#汽油,并试验研究了外特性和基于世界轻型汽车测试循环(WLTC)选取的部分负荷工况点油耗。在每种汽油和每个试验工况点下,发动机的进排气相位和点火角均调整至最优。结果表明:92#与95#汽油主要差异在于辛烷值,因95#汽油辛烷值较高,抗爆性更好,所以发动机点火角可以提前,提升了外特性性能,转矩和功率可增加1%~5%。对于部分负荷工况点油耗,在小负荷工况因无爆震限制,燃用2种汽油对发动机油耗基本无影响;而在大负荷工况,由于95#汽油抗爆性好,因此可提前点火从而改善油耗3.2%~4.8%。

In order to explore the influence of different grades of gasoline on engine performance,the full load performance and part load fuel consumption based on world light vehicle test cycle(WLTC)were studied by burning 92#and 95#gasoline on a turbocharged gasoline engine with port fuel injection.Under each fuel and each operating point,the intake and exhaust phases and ignition angles were optimized to the best.The results show that the main difference between 92#and 95#gasoline is octane number.Because 95#gasoline has higher octane number and better antiknock performance,so the ignition angle can be advanced and full load performance is improved.The torque and power can be increased by 1%~5%with 95#gasoline at full loads.For partial load fuel consumption,due to the absence of detonation restrictions at low loads,burning two types of gasoline has little effect on engine fuel consumption.At high loads,due to the good anti knock performance of 95#gasoline,the ignition angle can be advanced to improve fuel consumption by 3.2%~4.8%.