数据中心服务器CPU水冷散热器的优化设计

Optimal Design of CPU Water-cooled Radiator in a Data Center Server

如何强化水冷散热器的散热性能以维持计算机芯片的正常工作温度,成为数据中心服务器冷却问题研究的焦点。本文以水冷散热装置的综合系数F和芯片温度为目标参数,采用正交试验法对散热器的基板厚度、槽道(位于基板)位置、槽道数量和槽道宽度进行了优化设计,针对不同的需求得到最佳的组合为F指数和T指数散热器。结果表明:当冷却水体积流量为0.4 L/min,进口温度为20℃时,T指数和F指数散热器的散热极限热流密度分别为78 W/cm^2,65 W/cm^2。并从散热器底板的温度分布和总热阻两个方面分析其散热性能,T指数散热器的底板温度梯度和总热阻均低于F指数散热器,表明T指数散热器优于F指数散热器;但是在不同的体积流量下,F指数散热器的压降要低于T指数散热器。芯片在热流密度为65 W/cm^2以下时,F指数散热器槽道内流体的流动效果较好而且可满足数据中心服务器的散热要求,而更高的热流密度应选用T指数散热器进行冷却。

How to enhance the heat dissipation performance of water-cooled radiator to maintain the normal operating temperature of computer chips become the research focus of data center server cooling.In this paper,the comprehensive coefficient F and chip temperature of water-cooled radiator are taken as the target parameters.The orthogonal test method is used to optimize the thickness of the radiator′s substrate,the location of the channel(located on the substrate),the number of channels and the width of the channel.The optimal combination of F index and F index radiator is obtained according to different needs.The results showed that the maximum heat flux of the T and F index radiators was 78 and 65 W/cm^2,respectively,under a cooling water volume flow rate of 0.4 L/min and an inlet temperature of 20℃.The heat dissipation performance was analyzed from two aspects,i.e.,temperature distribution of the radiator basement and the total thermal resistance.It showed that the temperature gradient and total thermal resistance of the T index radiator were lower than that of the F index radiator,indicating that the T index radiator is superior to the F index radiator.However,the pressure drop of the F index radiator was lower than that of the T index radiator under different flow rates.When the chip heat flux was less than 65 W/cm^2,the flow performance of fluids in the channel of F index radiator was better and could meet the heat dissipation requirements of the data center server.Moreover,the higher heat flux should be cooled by the T index radiator.