大功率T/R组件相变温控平板热管的散热特性实验研究

Experimental Study on Heat Dissipation Characteristics of Flat Heat Pipe with Temperature-Controlled Phase Change Material Applied to High-Power T/R Module

为保证大功率相控阵天线T/R组件的长时间稳定工作,提出了一种相变储能平板热管的热控设计方案,该系统中的相变材料和平板热管分别发挥储热和热扩散的作用。实验对比了铝制平板热管和铝合金板的热扩散性能,以及它们分别和相变材料结合后的热控性能。实验结果表明,铝制平板热管的传热性能优于铝合金,在40 W时其冷凝端的最大温差为3.2℃,且等效热阻可维持在0.35 K/W以下;当热源置于侧边时,相比置于中间位置时的蒸汽扩散和液体回流路径较长,平板热管的热扩散性能下降;同时,与使用铝合金作为储热容器底部基板时的局部过热现象相比,采用相变储能平板热管的热控设计,可以将热源的热量进行均匀扩散,降低热流密度,从而表现出更好的温度均匀性,再通过相变储能的方式吸收热量,可以保证天线产品持续工作90 min时的结点温度控制在70℃。对于高纵横比的槽道式平板热管,需要进一步改良槽道的毛细结构,降低蒸汽扩散和液体回流路径的差异对热扩散性能的影响。

To ensure the stable operation of T/R components of high-power phased-array antennas for a long time,this paper proposes a thermal management strategy using the phase change energy storage and flat heat pipe,in which the phase change material and the flat heat pipe play the roles of heat storage and thermal diffusion,respectively.In this paper,the thermal diffusion features between the aluminum flat heat pipe and the aluminum alloy plate are compared,and their thermal management performance resulting from the combination with phase change materials are experimentally investigated.The experimental results show that the aluminum flat heat pipe depicts much better heat transfer performance than the same-size aluminum alloy plate,since the maximum temperature difference at the condensing side is 3.2℃at 40 W and the equivalent thermal resistance can be maintained below 0.35 K/W.When the heat source is shifted to the side,the thermal performance of the flat heat pipe rapidly drops due to the longer vapor diffusion and liquid reflux paths compared to the case at the middle position.Meanwhile,compared with the local overheating phenomenon when aluminum alloy is used as the bottom substrate of the heat storage container,the thermal control design of the flat heat pipe with phase change energy storage can diffuse the heat from the heat source evenly and reduce the heat flow density thus demonstrating better temperature uniformity,and then heat is absorbed by means of phase change energy storage,which can ensure that the junction temperature of the antenna product is controlled at 70℃when it works continuously for 90 min.For the channel type flat heat pipe with a high aspect ratio,the capillary structure of the channel needs to be further improved to reduce the influence of the difference of vapor diffusion and liquid reflux paths on the thermal diffusion performance.