废气再循环改善均质压燃发动机高负荷爆燃的试验研究

Experimental Study on the Improvement of Knock at High Load of a HCCI Engine By Exhaust Gas Recirculation

针对均质压燃发动机高负荷易爆燃的问题,在1台均质压燃发动机上加装废气再循环装置,把燃烧废气冷却后引入到进气中,在台架上进行试验并验证其可行性。试验结果表明,采用高浓度的EGR能够有效抑制HCCI发动机的爆燃并拓宽高负荷的工况范围,发动机峰值压力升高率降低,着火时刻推迟,有效放热时间增长,缸内最大压力峰值降低。

With regard to the HCCI engine knock at high load, an EGR apparatus was installed on a HCCI engine to verify the feasibility of ingesting cooled EGR into the intake to appease engine knock on an engine bench. The test results indicate that high EGR rate could effectively ease engine knock, enlarge the operating range at high load, reduce the peak pressure rise rate, delay the ignition timing, increase the combustion duration, and cut down on the peak cylinder pressure.