变海拔环境下的车用柴油机进气压力控制仿真研究

针对车用柴油机运行在高原地区外特性恶化的难题,提出了一种变海拔环境下柴油机进气压力控制方法,该方法通过调节高压级增压器旁通阀流通系数来动态调节二级涡轮可调增压系统压比。在基于最佳空燃比和最大输出功率的柴油机进气压力动态控制仿真基础上,建立了高压级增压器旁通阀流量系数与转速及大气压力的匹配关系。仿真试验表明,该方法大幅度降低了大气压力变化对柴油机外特性的影响,动力性和燃油经济性得到了明显改善。

Simulation of Intake Pressure Control for Vehicle Diesel Engine at Varying Altitude

A new method of intake pressure control at varying altitude for vehicle diesel engine was put forward to solve the external characteristics deterioration problem in plateau regions.The method could dynamically regulate the pressure ratio of two-stage supercharging system in real time by regulating the flow coefficient of bypass valve in the high pressure stage turbocharger.The matching relation of bypass valve flow coefficient with atmospheric pressure and rotating speed was established based on the intake pressure dynamic control simulation of diesel engine with optimal air-fuel ratio and maximal output power.The simulation experiment shows that the influence of atmospheric pressure variance on external characteristics decreases greatly and the power performance and fuel economy improve obviously by using this method.