To compute the matching performance of diesel engine with variable geometry turboeharger（VGT）, the formerly used program is improved through adjustment of turbine mass flow rate and efficiency characteristics. The c...To compute the matching performance of diesel engine with variable geometry turboeharger（VGT）, the formerly used program is improved through adjustment of turbine mass flow rate and efficiency characteristics. The calculation result is applied to forecast the performance of J6110Z diesel engine with rotary-vaned VGT70, and to guide the improvement of engine fuel supply. The computed engine performance curve coincides with the experiment result well： the low-speed torque, fuel economy, exhaust temperature and boost pressure of the VGT engine are all improved.展开更多
A spatial motion mechanism was designed which could make all the nozzle vanes rotate a- round the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger （V...A spatial motion mechanism was designed which could make all the nozzle vanes rotate a- round the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger （VN-MT）. The back and abdomen of the nozzle vane was designed as arc- shaped. A variable nozzle ring perfectly combined with the mixed-flow turbine was made available. The turbine geometric model of VN-MT was established through the computational fluid dynamics （CFD）. Compared with nozzleless mixed-flow turbine, the flow range of variable nozzle mixed-flow turbine was broadened tremendously while the peak turbine efficiency point was lower slightly. Flow field analysis in turbine stage showed that the energy was larger and the blade load of rotor was lower than loss of the VN-MT under designed condition the nozzleless mixed-flow turbocharger.展开更多
针对采用PID方法控制废气再循环(exhaust gas recirculation,EGR)和可变截面涡轮增压器(variable geometry turbocharge,VGT)阀开度时出现的进气质量流量和增压压力瞬态响应慢的现象提出了一种新的EGR与VGT解耦控制策略,并进行了试验验...针对采用PID方法控制废气再循环(exhaust gas recirculation,EGR)和可变截面涡轮增压器(variable geometry turbocharge,VGT)阀开度时出现的进气质量流量和增压压力瞬态响应慢的现象提出了一种新的EGR与VGT解耦控制策略,并进行了试验验证。研究结果表明:由工况点900r/min、200N·m变化至工况点1200r/min、1100N·m的过程中,采用解耦控制策略后,增压压力和进气质量流量的上升时间分别由8.5s和21.3s降至7.9s和16.8s,降幅分别为7.1%和21.1%;稳定时间分别由14.3s和18.3s降至11.5s和15.1s,降幅分别为19.6%和17.5%;WHTC测试循环下,解耦工况点占总工况点的比例达到36.1%,PM比排放和油耗的降低幅度分别为18.9%和5.8%,NOx比排放变化不明显。展开更多
A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and t...A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.展开更多
基金the Ministerial Level Advanced Research Foundation (37256)
文摘To compute the matching performance of diesel engine with variable geometry turboeharger（VGT）, the formerly used program is improved through adjustment of turbine mass flow rate and efficiency characteristics. The calculation result is applied to forecast the performance of J6110Z diesel engine with rotary-vaned VGT70, and to guide the improvement of engine fuel supply. The computed engine performance curve coincides with the experiment result well： the low-speed torque, fuel economy, exhaust temperature and boost pressure of the VGT engine are all improved.
基金Supported by the National Natural Science Foundation of China(51009003)
文摘A spatial motion mechanism was designed which could make all the nozzle vanes rotate a- round the center of ball with the same radius synchronously to realize control of the variable nozzle mixed-flow turbocharger （VN-MT）. The back and abdomen of the nozzle vane was designed as arc- shaped. A variable nozzle ring perfectly combined with the mixed-flow turbine was made available. The turbine geometric model of VN-MT was established through the computational fluid dynamics （CFD）. Compared with nozzleless mixed-flow turbine, the flow range of variable nozzle mixed-flow turbine was broadened tremendously while the peak turbine efficiency point was lower slightly. Flow field analysis in turbine stage showed that the energy was larger and the blade load of rotor was lower than loss of the VN-MT under designed condition the nozzleless mixed-flow turbocharger.
文摘针对采用PID方法控制废气再循环(exhaust gas recirculation,EGR)和可变截面涡轮增压器(variable geometry turbocharge,VGT)阀开度时出现的进气质量流量和增压压力瞬态响应慢的现象提出了一种新的EGR与VGT解耦控制策略,并进行了试验验证。研究结果表明:由工况点900r/min、200N·m变化至工况点1200r/min、1100N·m的过程中,采用解耦控制策略后,增压压力和进气质量流量的上升时间分别由8.5s和21.3s降至7.9s和16.8s,降幅分别为7.1%和21.1%;稳定时间分别由14.3s和18.3s降至11.5s和15.1s,降幅分别为19.6%和17.5%;WHTC测试循环下,解耦工况点占总工况点的比例达到36.1%,PM比排放和油耗的降低幅度分别为18.9%和5.8%,NOx比排放变化不明显。
基金Supported by Diesel Engine Development Program of MIIT(DEDP-1004)Natural Science Foundation of BIT(3030012211428)
文摘A turbocharged diesel engine model was built with the GT-Power software,and experimentally verified.Then two different control variables for the control of the variable geometry turbocharger（VGT）were described,and their distinct effects on engine performance,i.e.NOxand soot emissions and fuel consumption,were simulated and compared on the basis of this model.The results showed that NOxemissions decreased obviously with the increase of exhaust gas recirculation（EGR）rate at constant boost pressure condition,but soot emissions and fuel consumption considerably increased.It was a good way to reduce NOxemissions without increasing fuel consumption and soot emissions when VGT was controlled to maintain the excess oxygen ratio unchanged as EGR rate increases.
