基于(火积)分析的流体回路辐射器传热优化

Heat-transfer optimization of fluid loop radiator based on entransy analysis

为了优化流体回路辐射器的设计,基于(火积)理论,建立了辐射器散热速率与内部传热过程的(火积)耗散关系,进而构建了在给定辐射器体积约束条件下对辐射器(火积)耗散求极值的拉格朗日函数,并进行了偏导求优,结果表明辐射器面板内温度梯度大小处处相等,也就是热流密度处处均匀时,辐射器散出相同热量,流体回路工质温度最低,辐射器传热过程最优.根据辐射器内热流密度均匀分布的原则和工程应用的方便性,研究了采用梯形肋片截面的辐射器.结果表明在控制辐射器面板总体积不变的情况下,采用梯形截面辐射器面板,提高辐射器肋根厚度,可以优化辐射器传热性能,降低流体回路工质温度,提高辐射器散热能力.

To optimize the design of a liquid loop radiator based on entransy theory,the relationship between the heat dissipation rate and internal heat transfer process of a radiator was established.Then,the Lagrangian function was constructed to calculate the minimum value of the entransy dissipation of the radiator under limited radiator volume.The results show that the temperature gradient in the radiator panel is equal everywhere,i.e.,when the heat flux is uniform everywhere,the radiator heat-transfer process is optimal.Based on the principle of uniform distribution of heat flux in the radiator and considering engineering application convenience,a radiator with a trapezoidal fin section was studied.The results show that when the total volume of the radiator is controlled,using a radiator panel with a trapezoidal section and increasing the thickness of the root of the radiator fin can optimize the heat transfer performance of the radiator,reduce the temperature of the working fluid of the fluid loop,and improve the heat dissipation ability of the radiator.