Visualization Investigation on Temperature Oscillation and Two-Phase Behaviors of A Flat Loop Heat Pipe

作     者：DU Sheng ZHANG Quan LING Li ZOU Sikai LIU Lijun MENG Fanxi 

作者机构：College of Civil EngineeringHunan UniversityChangsha410082China School of Civil EngineeringHunan University of TechnologyZhuzhou412007China 

出 版 物：《Journal of Thermal Science》 (热科学学报（英文版）)

年 卷 期：2023年第32卷第4期

页      面：1536-1546页

核心收录：

学科分类：080904[工学-电磁场与微波技术] 080701[工学-工程热物理] 0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 

基　　金：This work was supported by National Natural Science Foundation of China(NSFC)(Grant No.51878254) National Key R&D Program of China(Grant No.2018YFE0111200) Key Research and Development Plan of Hunan Province(2020WK2012) Hunan Provincial Science and Technology Department(2020GK4057). 

主　　题：loop heat pipe temperature oscillation visualization observations two-phase flow patterns start-up characteristics vapor-liquid interface fluctuation 

摘      要：To better analyzing the temperature oscillation and the two-phase behavior inside a flat loop heat pipe,visual studies were conducted.Under the 20℃ water cooling and horizontal orientation,the effects of the filling ratio and heat loads on the temperature oscillation were analyzed.Based on the experimental data,the results indicate that owing to the increased system pressure,the temperature oscillation decays as the filling ratio increases from 34%to 58%.Meanwhile,during the startup process,temperature oscillation tends to occur during the boiling and steady stages due to the more violent two-phase behavior,while the temperature curves are smooth during the slow evaporation stage.Moreover,as the heat load increases,the evaporation becomes more intense at the active zone of evaporator,leading to a faster startup process and a higher oscillation frequency.Besides,owing to the synergistic effect of two-phase flow in the compensation chamber caused by heat leak and subcooled liquid backflowing,a“breathingoscillation behavior of the vapor-liquid interface is observed at the compensation chamber,which further leads to the unstable operation behavior of the loop heat pipe system.