多尺度复合毛细芯环路热管的传热特性

为解决环路热管在蒸发腔不同区域对于毛细芯孔径尺度和热导率的不同需求, 制备了一种多尺度复合毛细芯环路热管, 并在不同加热功率、放置角度和冷却方式下对环路热管进行了热性能测试。实验发现该环路热管具有较好的传热性能, 在200 W加热功率下, 蒸发腔壁面中心温度T_c最低仅为64℃。与风冷方式相比, 冰冷方式可以显著强化环路热管的传热性能, 降低T_c和热阻。热阻最低为0.19 K·W^-1。同时冰冷方式也有利于改善均温性。当加热功率不同时, 放置角度对环路热管温度及热阻的影响有所不同。另外, 多尺度复合毛细芯的应用有效地降低了热泄漏。随着加热功率的增加, 放置角度不同的LHP的热泄漏变化趋势不同。

Heat transfer characteristics of loop heat pipe with modulated composite porous wick

In order to suffice the different needs for pore size and thermal conductivity of wick in different evaporator regions of loop heat pipe (LHP), a LHP with modulated composite porous wick is constructed and investigated experimentally. The heat transfer characteristics of LHP are tested at different heating powers, inclination angles and cooling conditions. The results show that LHP has good heat transfer performances. The lowest temperature of the evaporator wall center (T_c) is only 64℃ at 200 W. The ice cooling can significantly promote LHP heat transfer performance, reducing T_c and thermal resistance, compared with the air cooling. The lowest thermal resistance is 0.19 K·W^-1. Besides, the ice cooling is helpful to improving the temperature uniformity of the evaporator wall. The effects of inclination angles on temperature and thermal resistance vary with the increase of the heating power. At low heating power, T_c of LHP with evaporator and condenser being the same altitude is lower than that with evaporator below condenser. As the heating power rises, the former becomes higher than the latter. In addition, the heat leak from evaporator to compensation chamber can be reduced by applying the modulated composite porous wick. With the increase of heating power, the effects of inclination angles on heat leak are different.