两种米勒循环对机车柴油机性能的计算分析与研究

Computation and Study of Effects of Two Kinds of Miller Cycle on Performances of Locomotive Diesel Engine

利用GT-Power软件建立某机车柴油机仿真计算模型,通过试验验证了仿真模型的准确性。对采用两种米勒循环时该柴油机在1 000r/min不同负荷条件下的功率、油耗和排放影响建立了仿真方案,在全负荷条件下进行了两种米勒循环对比。结果表明,两种方式米勒循环都能显著降低NO_x排放;综合分析柴油机各性能结果,选取变凸轮型线米勒循环、米勒度为30°曲轴转角为提高该机车柴油机性能的优化方案。该方法对机车柴油机应用米勒循环具有一定指导意义。

GT-Power software was used to establish the simulation model of a locomotive diesel engine,and the simulation model was verified by tests.Simulation cases were developed to study the influences of two kinds of Miller cycle on engine power,fuel consumption and emissions at 1 000 r/min with different loads,and the effects of these two kinds of Miller cycle were compared at full load.The study shows that both kinds of Miller cycle can decrease NO_x emissions.In terms of engine performances,the Miller cycle with modified intake cam profile and with intake valve lift profile moved by 30 degrees of crank angle is selected as an optimization plan for the locomotive diesel engine.This proposal can give guidelines to further researches on the application of Miller cycle to locomotive diesel engines.