原子能科学技术2024，Vol.58Issue(1)：50-59,10.DOI:10.7538/yzk.2022.youxian.0754
基于有限体积法碱金属高温热管冷态启动流动换热数值研究
Numerical Study on Flow and Heat Transfer of Alkali Metal High-temperature Heat Pipe during Frozen Startup Based on FVM
摘要
Abstract
In recent years,heat pipe has been widely used as an efficient heat transfer equipment in fuel chemistry,electronic communication and so on.The main structure of a heat pipe mainly includes the vacuum tube containing alkali metal working fluid and the composite mesh wick on the inner wall of the tube.In the axial direction,heat pipes are generally divided into three parts:evaporation section,adiabatic section and conden-sation section.Heat is input into the heat pipe through the evaporation section and output through the condensation section.The adiabatic section only plays a role in connecting and mass transfer.The length of each area can be flexibly arranged.In the radial direction,heat pipes are generally divided into outer wall surface,wick and vapor area.Alkali metal high-temperature heat pipes show broad application prospects in the nuclear reactor cooling and other aspects because of their strong heat transfer capacity and inherent safety at high temperature.Because the working fluid of these heat pipes is solid at room temperature,and whose saturated vapor pressure relatively low,their frozen start-up has a complex phase change process of the working fluid,so it brings some difficulties to the study of the frozen start-up of the high-temperature heat pipes.For different application scenarios,it is necessary to study the transient and steady-state operating characteristics of high-temperature heat pipes,to provide support for the application of high-temperature heat pipes in a variety of applicable scenarios.To estab-lish a method for predicting the transient start-up and steady-state operation characteris-tics of alkali metal high-temperature heat pipes,this study utilized the finite volume method(FVM)to establish the pipe wall heat conduction model,the wick flow heat transfer model,and the vapor zone model.A frozen start-up transient analysis program for alkali metal high-temperature heat pipes was developed and verified using the C programming language,with a maximum relative deviation of 9.8％.Transient start-up of a single horizontal sodium heat pipe was simulated,and sensitivity analysis was conducted.The steam zone of the heat pipe enters the continuous flow state completely 700 seconds after start-up,and after a total of 3 000 seconds,the heat pipe reaches steady-state operation.Under steady-state operation,the heat pipe exhibits good iso-thermal properties,with a stable axial temperature difference of 22.5 K on the outer wall and an internal pressure drop of approximately 47 Pa in the wick.Furthermore,the ambient temperature primarily impacts the time required for the heat pipe to reach stead-y-state,as well as the vapor pressure and velocity distribution under steady-state condi-tions.Meanwhile,the length of the adiabatic section of the heat pipe influences the time required for it to reach steady-state and has a significant effect on the pressure and velocity distribution of the wick.关键词
高温热管/数值模拟/冷态启动/有限体积法Key words
high-temperature heat pipe/numerical simulation/frozen start-up/finite volume method分类
能源科技引用本文复制引用
赵昊城,张泽秦,王成龙,秋穗正,田文喜,苏光辉..基于有限体积法碱金属高温热管冷态启动流动换热数值研究[J].原子能科学技术,2024,58(1):50-59,10.基金项目
国家自然科学基金(U2067208) （U2067208）
