不同排气系统对涡轮增压柴油机性能的影响

以某增压中冷柴油机为研究对象，利用GT-POWER软件建立了该增压中冷柴油机工作过程仿真模型，并根据试验数据进行了校核计算.在上述工作的基础上，对增压柴油机的三脉冲排气系统进行了改型设计，建立了MPC排气系统和定压排气系统仿真模型，验证了模型的有效性.通过对三种排气系统的仿真及对比分析，表明MPC及定压排气系统选取合理的较小排气管径能够降低发动机油耗，减弱涡轮进口压力脉动，保证较高的涡轮效率和功率输出；发动机额定工况下，三种排气系统对发动机及涡轮性能的影响存在明显差异，三脉冲系统的发动机性能优于MPC与定压排气系统；发动机中低转速时，MPC系统使得涡轮效率较三脉冲与定压系统有所提升. 

Effects of the Exhaust System on the Performance of a Turbocharged Diesel Engine

Based on the CA6DL turbocharged diesel engine, the engine model was built in GT-POWER and validated with the test data. Both the MPC exhaust system and constant pressure exhaust system models were built and compared with the three pulse exhaust system. It was indicated that suitable exhaust pipe diameter could not only reduce the fuel consumption of engine but also enhance the power and efficiency of turbine. The result comparisons also show that the three exhaust systems have different influences on the performances of the engine and the turbine. At engine full load conditions, the performance of the engine with the pulse exhaust system is better than the engines with both MPC and constant pressure systems. At the low and medium speed conditions, MPC exhaust system achieves a higher turbine efficiency than the other two exhaust systems.