高温两相闭式热虹吸管的瞬态气液相变数值模拟研究  

Numerical simulation on transient vapor-liquid phase change of high temperature two-phase closed thermosyphon

作　　者：沈妍[1] 刘锐 耿伟轩 于萍[3] 姚寿广 SHEN Yan;LIU Rui;GENG Weixuan;YU Ping;YAO Shouguang(School of Mechanical and Power Engineering, Jiangsu University of Science and Technology, Zhangjiagang 215600, China;Jiangsu Province Qinhuai River Water Conservancy Project Management Office, Nanjing 210000, China;College of Mechanical and Electrical Engineering,Xuzhou University of Technology,Xuzhou 221018, China;School of Energy and Power, Jiangsu University of Science and Technology, Zhenjiang 212100, China)

机构地区：[1]江苏科技大学机电与动力工程学院,张家港215600 [2]江苏省秦淮河水利工程管理处,南京210000 [3]徐州工程学院机电工程学院,徐州221018 [4]江苏科技大学能源与动力学院,镇江212100

出　　处：《江苏科技大学学报（自然科学版）》2022年第2期48-55,共8页Journal of Jiangsu University of Science and Technology:Natural Science Edition

基　　金：江苏省高等学校自然科学研究面上项目(20KJD470001)。

摘　　要：为了探究钠不锈钢高温热虹吸管内液钠沸腾气化和冷凝液膜的形成机理,建立了高温热管气液相变传热传质模型采用VOF气液界面追踪法对高温两相闭式热虹吸管瞬态气液相变过程进行数值模拟研究,得到了高温热虹吸管内液钠气化和冷凝界面随时间的变化过程.通过对热管内瞬时气液体积分数分析,蒸发段壁面处先形成气化核心,产生蒸汽后扰动液池、气泡溢出和壁面处原气泡位置由液体填入;气流从蒸汽腔中间上升到冷凝段顶端向两边散开,在壁面上冷凝形成自上而下的液膜回流,液膜厚度先增大后减小;局部的壁面处有气液逆流现象,当气流速度较大时,发生液体夹带,使冷凝液离开壁面形成含液量不等的小液滴.通过对热管内轴向气流速度分析,管内沿轴向蒸发段气流速度增大,绝热段气流速度几乎不变,冷凝段速度逐渐下降.模型再现了高温热虹吸管内气液相变瞬态过程,丰富了高温热管的模拟研究.In order to explore the mechanism of boiling gasification and condensate film formation in high temperature thermosyphon with liquid sodium as working fluid and stainless steel as wall material,a heat and mass transfer model of vapor-liquid phase change in high temperature heat pipes is established.The VOF vapor-liquid interface tracking method is used to numerically simulate the transient vapor-liquid phase transition process of the high temperature two-phase closed thermosyphon,and the transient process of the liquid and vapor interface in the vaporization and condensation process is obtained.By analyzing the instantaneous vapor phase volume fraction in the heat pipe,the vaporization core is first formed on the wall of the evaporation section.After the steam is generated,the liquid pool is disturbed,and the bubbles overflow and the space near the wall surface is filled with liquid.The airflow rises from the middle of the vapor core to the top of the condensing section and spreads out to both sides,and condenses on the wall to form a top-down liquid film reflux.The thickness of the liquid film first increases and then decreases.There is vapor-liquid countercurrent phenomenon on the local wall.When the airflow velocity is high,liquid entrainment occurs,forming small droplets with different vapor phase volume fraction left from the wall.By analyzing the axial velocity in the heat pipe,the vapor velocity along the axial direction increases in the evaporating section,almost keeps constant in the adiabatic section,and gradually decreases in the condensation section.The simulation reproduces the transient process of the gas-liquid phase change in the high-temperature thermosyphon,which enriches the simulation research of the high-temperature heat pipe.

关 键 词：高温热虹吸管 气液相变 流体体积法 瞬态 

分 类 号：TK172.4[动力工程及工程热物理—热能工程]