车用柴油机瞬态特性劣变机理及优化策略

Transient Performance Deterioration Mechanism and Optimization Strategy for Vehicle Diesel Engine

在瞬态工况下,车用柴油机存在压气机喘振和倒流、增压压力响应滞后、转矩突降、燃油消耗量和有害排放物增加等问题。从柴油机关键性能参数响应、缸内燃烧过程、缸内微观物理场等3个层次分析柴油机及增压器瞬态性能劣变原因,综述国内外解决增压柴油机瞬态特性劣变的几种对策:涡轮机内部非定常流动控制、喷油参数调整、二级可调增压系统、EGR阀控制、先进的控制策略等。最后,从柴油机瞬态特性劣变机理、柴油机多系统协同控制和变海拔柴油机瞬态特性优化等3个方面提出下一步柴油机瞬态特性研究发展的方向。

In transient conditions,vehicle diesel engine shows some problems,like the hysteresis response of boost pressure,sudden dive of torque,compressor surge and backflow,the increasing of fuel consumption and harmful emissions.The reasons for the transient performance deterioration of diesel engine and turbocharger were analyzed from three levels:the response of the key performance parameters,the combustion process and the microphysical field in the cylinder.The paper reviews several solutions to solve the problems,including the nonsteady flow control in the turbocharger,the adjustment of fuel injection parameters,the two stage regulated turbocharger system,the control of the EGR valve,the advanced control strategy and so on.At last,It was pointed out the direction of research and development of diesel engine transient characteristics from the transient characteristics deterioration,multi-systems coordination control and improvement on transient response of diesel engine at varying altitudes.