Abstract:

In order to apply the loop heat pipe (LHP) in the fields of thermal management of the devices in motion, a capillary wick with 0.3mm aperture was manufactured by 3D-printed technology, and a controllable periodic horizontal swing platform was established to investigate the effect of varying horizontal swing speeds [0, 5(°)/s, 10(°)/s, 15(°)/s, 20(°)/s, 25(°)/s] on the heat transfer performance of the LHP through the comparative experiments. It was indicated that the start-up time was prolonged in motion, and the start-up time increased with the increase of swing speed. Additionally, it was more likely to induce steam to penetrate the capillary wick under low heat load, which adversely affected the stable operation of the LHP. However, relatively low swing speeds contributed positively to improving LHP's stable operation performance. For the first time, it was found that at a swing speed of 10(°)/s, the maximum heat load achievable by the LHP was 160W, an increase of 20W compared to the LHP in still. The evaporator thermal resistance of the LHP with a swing speed of 10(°)/s was reduced by 1.7% at a heat load of 140W.

Key words: heat transfer, phase change, evaporation, swing speed, loop heat pipe

摘要：

为拓展环路热管（loop heat pipe，LHP）在运动设备散热中的应用，本文利用3D打印技术制备了孔径为0.3mm的直通孔毛细芯，并设计了一个可控的水平摆动实验平台，通过实验研究了不同水平摆动速度[0、5(°)/s、10(°)/s、15(°)/s、20(°)/s、25(°)/s]对LHP传热性能的影响。结果表明，针对该类LHP，摆动会延长LHP启动时间，随着摆动速度的提高，LHP的启动时间也随之变长。并且，摆动在低热负荷时更易诱发蒸汽穿透毛细芯，对LHP的稳定运行产生不利影响。然而，研究同时也首次发现较小的摆动速度却有利于提升LHP的稳定运行性能：在10(°)/s的摆动速度下，LHP能够承受的最大热负荷为160W，比静止状态下高出20W；此外，在140W热负荷条件下，以10(°)/s摆动速度运行的LHP蒸发器热阻相比静止状态降低了1.7%。

关键词: 传热, 相变, 蒸发, 摆动速度, 环路热管