Abstract:

In the loop heat pipe (LHP), the structure of the evaporation section is the most complex, and the capillary wick is a part that directly affects its working performance, so it has a great research value. To simulate the real operation of the capillary wick in LHP, an experimental device was designed to measure the surface temperature during the operation at room temperature. The heat transfer capacity of the capillary wick in the evaporative section of LHP was studied independently. The experimental study consisted of measuring the effective thermal conductivity using ethanol and water as working fluid at different heating power. It was found that the effective thermal conductivity of the ethanol-containing capillary wick is higher than that of the water-containing capillary wick at low heating power, while the results were reversed at high heating power. The conclusion of this experiment has a certain reference value for the evaluation of the heat transfer performance of the capillary wick, and it can also provide some experimental data for the simulation of the LHP evaporator.

Key words: steady state, evaporation, effective thermal conductivity, porous media, loop heat pipe

摘要：

在环路热管（LHP）中，蒸发段的结构最为复杂，而其中的毛细芯是直接影响热管工作性能的部分，因此有很大的研究价值。为模拟LHP中毛细芯的真实运行情况，设计了一台在常温下测定毛细芯工作时表面温度的实验装置，对环路热管蒸发段毛细芯的传热能力进行独立的实验研究，分别采用乙醇和水为工质，在不同的加热功率下，计算毛细芯的有效热导率。研究发现，在低加热功率下，含乙醇的毛细芯的有效热导率要高于含水的毛细芯的有效热导率；而在高加热功率下，实验结果正好相反。本次实验的结论对于毛细芯传热性能的评估具有一定参考价值，也可以为LHP蒸发器的模拟仿真提供一定的实验数据。

关键词: 稳态, 蒸发, 有效热导率, 多孔介质, 环路热管