Experimental analysis of a Vapour-Liquid Separated Flat Loop Heat Pipe Evaporator System

¹ Tianjin University, School of Architecture, 300072 Tianjin, China
² Tianjin University of Commerce, Key Laboratory of Refrigeration Technology of Tianjin, 300134 Tianjin, China
³ Fujitsu LTD, 2118588 Tokyo, Japan

^* Corresponding author: sarul@tju.edu.cn

Abstract

In this paper, a unique operation mechanism of loop heat pipe (LHP) was proposed. To test the performance of LHP under this new mechanism, a visual flat LHP evaporator prototype and an open experimental system were designed and assembled, and start-up experiment and variable heat load experiment were done respectively to obtain the actual operation characteristics, such as the evaporator thermal resistance (R_e), total thermal resistance (R_t), start-up time and temperature of base plate. The proposed LHP had better overall performance during the start-up tests when H_e value of EC was set to 0.5mm, and its corresponding R_e and R_t value were 0.035 K/W and 0.451 K/W when the heating power was 208w. Meanwhile, as per the heat load applied to the base plate, the whole variable heat load experiment could be divided into three distinct stages: low heat load stage, efficiency operation stage and dry-out stage. Moreover, the results also showed that the circulation driven head formed inside of the EC played an important role in promoting the operation performance, especially when the wick, the vapour-liquid interface and the bottom of the evaporator arrived at a reasonable situation.