VNT增压柴油机与整车速度瞬态响应的试验分析

对装有可变喷嘴涡轮增压器(VNT)的柴油机客车在高原地区与平原地区上的起动、起步加速、换挡加速及减速等变工况下瞬态特性进行了试验研究。对VNT的瞬时转速、发动机转速、汽车速度等参数进行了对比分析。研究结果表明,起动时,VNT转速滞后于发动机的转速;起步加速工况,VNT转速随发动机转速变化的瞬态响应快;换挡加速工况,VNT的转速随发动机转速增加而增加;减速工况,发动机转速下降,VNT转速呈现下降趋势。VNT的有效调节,控制了涡轮不超速,可以改善涡轮增压柴油机的瞬态特性,有利于整车变工况行驶性能的提高。

Analysis of the Velocity Transient Response of VNT in Turbocharged Diesel & Vehicle

This paper is based on the experiment of variable nozzle turbocharger(VNT) of turbocharged diesel vehicle in plateau and plain under different operating states,which are starting,accelerating and slowdown.And made the test research on the transient speed of VNT and diesel engine and the velocity of vehicle in plain and plateau.These parameters have been compared and analysed.The result of study shows that the speed of VNT lags behind in the speed of engine in engine starting operating model,transient response of the speed of VNT varies fast with the speed of the engine in starting and accelerating operating mode,the speed of VNT increases with increasing of the speed of the engine in gear changing and accelerating operating model,VNT speed presents the downward trend when the speed of the engine drops in moderating the operating mode.For VNT effective regulation,the turbine does not overspeed.VNT can improve the transient state characteristic of the turbocharged diesel engine,and benefits the steering performance of the vehicle in different operating mode.