基于VGT控制参数的柴油机低速变海拔热平衡试验  

Experimental study on thermal balance of diesel engine at low speed affected by VGT control parameters at variable altitudes

作　　者：杨春浩[1] 刘瑞林 张众杰 焦宇飞 YANG Chun-hao;LIU Rui-lin;ZHANG Zhong-jie;JIAO Yu-fei(College of Power Engineering,Naval University of Engineering,Wuhan 430033,China;Department of Military Vehicle,Army Military Transportation University,Tianjin 300161,China)

机构地区：[1]海军工程大学动力工程学院,湖北武汉430033 [2]陆军军事交通学院军用车辆系,天津300161

出　　处：《热科学与技术》2019年第3期206-213,共8页Journal of Thermal Science and Technology

基　　金：国防预研资助项目(30105030201)

摘　　要：进行二级可调增压柴油机热平衡性能研究,有助于解决高海拔发动机开锅问题,提高热效率。利用自主设计的柴油机高海拔热平衡试验系统,进行不同模拟海拔(0、3 500、5 500 m)基于可变截面涡轮增压器(VGT)控制参数的二级可调增压柴油机低速全负荷热平衡试验,全面分析了变海拔条件下VGT控制参数对整机低速热平衡性能影响的机理与规律,优化标定了不同海拔下柴油机低速最佳VGT叶片开度。结果表明:随VGT叶片开度增大,发动机低速工况下热负荷升高,表现形式为涡前排温升高、缸内最高燃烧温度上升,但缸内最大燃烧压力呈下降趋势,0 m、VGT开度小于50%时,缸内最高燃烧压力大于17 MPa,在0、3 500、5 500 m海拔,VGT开度分别大于70%、50%、30%时,缸内最高燃烧温度超过2 200.0℃。随VGT叶片开度增大,柴油机有效功率、排气带走热量及其占比升高,冷却液带走热量、余项损失及其占比呈下降趋势,5 500 m海拔下,VGT叶片开度每增大10%,柴油机热效率降低3.1%。综合考虑VGT控制参数对缸内最高燃烧温度、缸内最大燃烧压力及热效率的影响,0、3 500、5 500 m柴油机低速工况最佳VGT叶片开度应分别为50%、20%、20%。The research on thermal balance performance of regulated two-stage turbocharged(RTST) diesel engine is helpful to solve the problem of coolant boiling and improve thermal efficiency at high altitudes. The full load thermal balance tests of RTST diesel engine with low speed at different simulated altitude(0, 3 500 and 5 500 m) based on variable geometry turbocharger(VGT) control parameters were carried out on the high altitude thermal balance test system for diesel engine. The influence of the VGT control parameters on the thermal balance of the diesel engine with low speed at variable altitudes was analyzed comprehensively, and the optimal openings of VGT vane at different altitudes were calibrated. The results show that with the increase of VGT vane opening, the heat load of the engine at low speed rises, which shows that the exhaust temperature and the maximum combustion temperature in the cylinder increase, but the maximum combustion pressure in the cylinder decreases. When the opening of VGT vane at 0 m is less than 50%, the maximum combustion pressure in cylinder is obviously greater than 17 MPa. At the altitude of 0, 3 500 and 5 500 m, when the opening of VGT vane is respectively greater than 70%, 50% and 30%, the maximum combustion temperature in the cylinder exceeds 2 200 ℃. With the increase of the VGT vane opening, the effective power of the diesel engine, the exhausting heat and the proportion of them increase, while the heat taken away by coolant, the remainder heat loss and the proportion of them show a downward trend. At 5 500 m altitude, the thermal efficiency of diesel engine at low speed decreases by 3.1% with the opening of VGT vane increasing by 10%. The influences of VGT control parameters on maximum combustion temperature, maximum combustion pressure and thermal efficiency in cylinder are considered comprehensively, for 0, 3 500 and 5 500 m, the best VGT vane opening at low speed should be 50%, 20% and 20% respectively.

关 键 词：二级可调增压柴油机 低速 VGT叶片开度 高海拔 热平衡 

分 类 号：TK412[动力工程及工程热物理—动力机械及工程]