摘要
为了研究不同大气压力下可变喷嘴涡轮增压技术(Variable Nozzle Turbine,VNT)和排气再循环技术(Exhaust Gas Recirculation,EGR)对柴油机性能及排放的影响,选择带有EGR与VNT的高压共轨柴油机,应用大气模拟装置,在80、90和100 kPa下进行试验研究.试验结果表明:1800 r/min、73％负荷工况下,在不同大气压下,过量空气系数随着VNT喷嘴环开度的增加而上升,升高幅度随EGR阀开度的增加而增大;过量空气系数随着EGR阀开度的增加而减小.EGR率和比油耗随VNT喷嘴环开度的增加而下降,前者降低幅度随大气压力的增加而上升,后者降幅随大气压力的降低而升高;EGR率随EGR阀开度的增加而上升.随VNT喷嘴环开度的增加,NOx排放升高,升高幅度随EGR阀开度的增加而增大,升高幅度基本随大气压力的升高而下降.CO排放与烟度均随VNT喷嘴环开度的增加而降低,降低幅度随EGR阀开度的增加而升高,随大气压力的升高而降低.随EGR阀开度的增加,NOx排放降低,CO排放与烟度升高.
Abstract
In order to study the effects of Variable Nozzle Turbine(VNT) and Exhaust Gas Recirculation(EGR) technologies on the performance and emissions of a diesel engine under different atmospheric pressures,a high-pressure common rail diesel engine equipped with EGR and VNT was selected.An atmospheric simula-tion device was employed to conduct experimental research at 80,90,and 100 kPa.The experimental results in-dicate that,at 1800 r/min and 73％ load conditions,under different atmospheric pressures,the excess air ratio increases with the opening of the VNT nozzle ring and the increase in this trend is amplified with the opening of the EGR valve.The excess air ratio decreases with the opening of the EGR valve.Both EGR rate and specific fuel consumption decrease with the opening of the VNT nozzle ring.The reduction in EGR rate increases with the rise in atmospheric pressure,while the reduction in specific fuel consumption increases with the decrease in at-mospheric pressure.The EGR rate increases with the opening of the EGR valve.With the increase in the open-ing of the VNT nozzle ring,NOx emissions increase,and this increase is amplified with the opening of the EGR valve.The magnitude of increase generally decreases with the rise in atmospheric pressure.Both CO emissions and smoke decrease with the opening of the VNT nozzle ring.The reduction in these emissions increases with the opening of the EGR valve and decreases with the rise in atmospheric pressure.With the increase in the opening of the EGR valve,NOx emissions decrease,while CO emissions and smoke increase.
NETL
NSTL
维普
万方数据