Abstract:

The capillary wick is a core component of the heat pipe. A single uniform pore capillary wick is often difficult to take into account the needs of high-performance heat pipe for capillary pumping and permeability at the same time. Variable pore capillary wick can set the required capillary pumping and permeability respectively according to the needs. In this paper, fiber felt was used as the main material to prepare variable pore capillary wicks with different pore distribution, and built a flat plate heat pipe test-bed with variable pore capillary wick. Through experiments, the effects of pore distribution and other parameters of capillary wick on the starting performance and heat transfer performance of heat pipe were studied. The results showed that the heat pipe with variable pore composite capillary wick had shorter startup time and better heat transfer performance than that with uniform pore capillary wick. When other conditions were the same and the inclination angle was 45°, the heating power of the flat plate heat pipe with reduced pore diameter capillary wick in the reflux direction was about 2W higher than that of the flat plate heat pipe with uniform capillary wick and 3—4W higher than that of the gravity heat pipe.

Key words: capillary wick, variable pore, pumping performance, flat heat pipe, heat transfer, evaporation, mass transfer

摘要：

毛细芯是热管的核心部件，单一均匀孔隙毛细芯往往难以同时兼顾高性能热管对于毛细抽吸力和渗透率两方面的需求，变孔隙毛细芯则可以根据需要分别设置变化的内部孔隙分布，同时满足所需要的毛细抽吸力和渗透率。本文以纤维毡为主要材料制备不同孔隙分布的变孔隙毛细芯，搭建变孔隙毛细芯平板热管实验台，通过实验研究毛细芯的孔隙分布等参数对平板热管的启动性能和传热性能的影响，研究结果表明：含有变孔隙复合毛细芯的平板热管比含均匀孔隙毛细芯的平板热管性能更好，启动所需的时间更短，热管的传热性能也更好。其他条件相同，倾斜角度为45°时，回流方向孔径递减毛细芯平板热管能承受的加热功率比均匀毛细芯平板热管高约2W，比重力热管高3～4W。

关键词: 毛细芯, 变孔隙, 抽吸性能, 平板热管, 传热, 蒸发, 传质