Performance comparison regarding loop heat pipes with different evaporator structures
Publication date: February 2019
Source: International Journal of Thermal Sciences, Volume 136
Author(s): Xueqiang Li, Kai Zhu, Hailong Li, Xiaoqing Chen, Yabo Wang
The design of evaporator can clearly affect the performance of loop heat pipes (LHPs). In order to understand the influence, three different designs of evaporators were compared, including embedding vapor channels on the heating surface (Config_1), embedding vapor channels in the wick (Config_2), and separating the wick from the heating surface (Config_3). Based on the validated model, the operating temperature, the start-up time, and the transport distance, as key performance indicators, were studied. Results show that, to improve the performance of LHP, it is of importance to reduce the contacting area between the wick and the heating surface. Due to the existence of the steam chamber, the wick was separated from the heating surface in Config_3, resulting in the lowest operating temperature and the shortest start-up time. The pressure head of evaporation is also an important component of the driving force. For Config_3, since the evaporation happened in the steam chamber rather than in the wick, it had a longer transport distance than Config_1 and Config_2 at the same heat load.