Abstract: Under the high-speed condition of international heat balance, the water temperature of a gasoline engine with a pickup truck exceeds 115 ℃, resulting in the engine torque limit and the test can not pass. To solve the problem of high equilibrium water temperature in this working condition, the AMESim exhaust pressure field heat transfer model is established fristly, and the results of domestic heat balance tests are used to calibrate the simulation model, and then the simulation is carried out according to the boundary matrix of schemes such as increasing the pump speed ratio, increasing the fan and replacing the new radiator, so as to compare the influence of different boundary states on the engine equilibrium water temperature. The results show that the combination of large fan and new radiator can meet the international heat balance high speed condition without adjusting the pump speed ratio, and the equilibrium water temperature of the final test is basically the same as the simulation results. This method can quickly lock the hardware state that meets the test requirements and reduce the work of test selection.

Key words: Thermal balance; Engine; AMESim

摘要： 某汽油机配皮卡车型在国际热平衡的高速工况下出现水温超 115 ℃，导致发动机限扭， 试验无法通过的情况。为了解决该工况平衡水温高的问题，首先建立 AMESim 发舱压力场换 热模型，且利用国内热平衡试验的结果对仿真模型进行标定，后续按照增大水泵速比、增大 风扇、更换新散热器等方案的边界矩阵进行仿真，以对比不同边界状态对发动机平衡水温的 影响。结果表明，采用大风扇和新散热器的组合方案即可满足国际热平衡高速工况，无需调 整水泵速比，且最终试验的平衡水温与仿真结果基本相同。该方法能够快速锁定满足试验需 求的硬件状态，减少试验选型的工作。

关键词: 热平衡；发动机；AMESim