强化流道内R134a沸腾换热数值模拟

Numerical Simulation of R134a Boiling Heat Transfer in Enhanced Flow Channels

为了提高动车组CRH3运行中牵引变流器冷却基板流体沸腾换热冷却效果,设计了一种新型四面体肋板结构。采用CFD数值模拟计算的方法,建立了三维单流道模型,对不同肋板高度和入口速度与沸腾换热之间的规律进行分析。结果表明:随着肋板高度的增大,换热系数逐渐升高;肋板的扰动作用提升了流动速度,强化了流动涡旋,可提高对流换热性能;随着入口速度的增大,热源壁面温度方差降低,散热均匀性提高,但流动能耗也随之提高。

In order to improve the cooling effect of the fluid boiling heat transfer of the traction converter cooling substrate during the operation of CRH3 of EMU,a new tetrahedral rib structure is designed,and a threedimensional single-channel model is established by using the CFD numerical simulation method.The law between different rib height and inlet velocity and boiling heat transfer is analyzed.The results show that the heat transfer coefficient is increased with the increase of the rib height.The disturbance of the ribs enhances the flow velocity,strengthens the flow vortex,and improves the convective heat transfer performance.With the increase of inlet velocity,the wall temperature variance of the heat source is decreased,and the heat dissipation uniformity is increased with the increased flow energy consumption.