相继涡轮增压柴油机推进特性的稳态及瞬态试验研究

Experimental Research on Steady and Transient Performances of Propulsion Characteristics of Diesel Engine with Sequential Turbocharging System

对某柴油机采用大小涡轮相继增压系统进行了推进特性的稳态及瞬态试验研究。对柴油机分别采用小涡轮增压器、大涡轮增压器以及大小2台涡轮增压器并联3种增压方案进行推进特性的稳态试验,并对试验结果进行了比较分析,确定了该相继增压系统的两个切换工况点分别为40%和80%负荷工况。在各切换工况下进行了阀门不同切换时间的瞬态试验,通过分析切换过程中发动机各性能参数的变化,确定了各阀门的开闭顺序及延迟时间:在40%和80%负荷工况点切换时,阀门VCS滞后阀门VTS开启的最佳时间分别为0.6s和0.4s,阀门VCS滞后阀门VTS关闭的最佳时间均为0.2s。

Steady and transient performances of propulsion characteristics of a diesel engine with sequential turbocharging （STC） system consisting of a big turbocharger and a small one were investigated. The steady propulsion characteristics of the diesel engine were studied in three schemes： with only a small or a big turbocharger and with both turbochargers. By analyzing the experimental results, the two mode switc- hing points of the STC system are determined at 40 % and 80 ~ load conditions. The transient experiments for different switching valve timings at the two mode switching points were conducted. Examined the fluctuations of engine performance parameters in the switching process, the open and close order and lag time of valves are confirmed： in switching processes at the 40% and the 80% load points, optimal opening timing lags of the valve VCS behind the valve VTS are 0.6 s and 0.4 s respectively, and the optimal closing timing lags are both 0. 2 s.