U型重力热管启动过程中压力和温度的演变规律  

Evolution of Pressure and Temperature During Start-up Process in U-Shaped Gravity Heat Pipe

作　　者：赵萧涵 刘圣春[1,2] 李雪强[1] 张钟垚 李海龙 Zhao Xiaohan;Liu Shengchun;Li Xueqiang;Zhang Zhongyao;Li Hailong(Key Laboratory of Refrigeration Technology of Tianjin,Tianjin University of Commerce,Tianjin,300134,China;Key Laboratory of Efficient Utilization of Low and Medium Grade Energy,Tianjin University,Tianjin,300350,China)

机构地区：[1]天津商业大学天津市制冷技术重点实验室,天津300134 [2]天津大学中低温热能高效利用教育部重点实验室,天津300350

出　　处：《制冷学报》2024年第6期106-113,共8页Journal of Refrigeration

基　　金：国家自然科学基金(52077044)资助项目;天津市教委科研计划项目(2021ZD031)资助。

摘　　要：重力热管因具有高效的导热性能受到广泛关注。通过将饱和温度和工质物性变化引入VOF模型,研究了U型重力热管的启动过程,并对启动过程中的压力和温度进行分析。结果表明:使用改进后的模型可与实验数据更好地吻合,模拟与实验值平均误差仅为5 K,具有较高的模拟精度。基于模拟结果,可将启动过程分为初始阶段、平衡阶段和突变阶段;初始阶段的主要特征为绝热段和冷凝段的温升均滞后于蒸发段,蒸发段和冷凝段间的压力差出现小幅波动(平均波动范围为81.5 Pa);平衡阶段的特征是冷凝段温度上升,蒸发段和冷凝段间的压力差波动幅度增大(平均波动范围为230.2 Pa),并出现间歇沸腾现象;突变阶段的主要特点是温度出现波动,同时压力波动更为剧烈。Gravity heat pipes garner attention owing to their high thermal conductivities.In this study,the variable saturation temperature and variable physical properties of the working medium were added to the VOF model.The start-up process of a U-shaped gravity heat pipe was studied,and the evolutions of pressure and temperature during the start-up process were thoroughly discussed.The improved model could be better validated by the experimental data.The average deviation was only 5 K,which shows a high accuracy.Based on the simulation results,three stages can be divided:initial,equilibrium,and variation stages.In the initial stage,the temperature increase for the adiabatic and condensation section was hysteretic compared to that of the evaporation section,and small fluctuations of pressure difference between the evaporation and condensation sections could be observed(the average fluctuation was 81.5 Pa).In the equilibrium stage,the temperature increase for the condensation section was obtained.There were more obvious fluctuations in the pressure difference between the evaporation and condensation sections(the average fluctuation was 230.2 Pa),in which geyser boiling could be observed.In the variation stage,both temperature and pressure exhibited fluctuations.The pressure fluctuation was more obvious.

关 键 词：重力热管 VOF模型 启动过程 压力 温度 导热系数 

分 类 号：TB611[一般工业技术—制冷工程] TB657.5