摘要
钠热管在相关小型化、无人化核反应堆平台上有着良好的应用前景,其工质蒸发调节系数的准确性对于钠热管分析具有重要的意义。而蒸发调节系数受温度的影响显著,为此,通过实验方法研究了不同温度对钠热管内钠蒸发调节系数的影响。通过改变加热功率、倾角、加钠量、丝网等参数,测量了稳态工况下的轴向外壁面温度及气相温度。采用不同蒸气温度取值方法,结合外壁面温度测量值,基于HertzKnudsen-Schrage方程获得了蒸发调节系数的实验值。分析表明,使用蒸发段局部气相温度作为蒸气温度获得的蒸发调节系数受管内工况及丝网参数影响较小,蒸发调节系数的对数值与对数饱和压力满足良好的线性关系;使用绝热段壁面温度或绝热段气相温度作为蒸气温度获得的蒸发调节系数,在550℃以下时受轴向导热热阻及液钠润湿不佳的影响,数值偏小但依然满足对数线性关系,而在高于550℃时液钠良好润湿性带来的轴向铺展可显著增大蒸发调节系数,此时丝网的作用较为明显。通过拟合实验数据,建立了不同温度下的蒸发调节系数的经验关系式。
Due to its advantages of higher heat flux and wider operating temperature range,sodium heat pipes have shown promising application prospects in related miniaturized and unmanned nuclear reactor platforms.The accuracy of the working fluid's evaporation accommodation coefficient(acc) in sodium heat pipes holds significant importance for their thermal transport analysis.According to existing research,it has been found that the evaporation characteristics of the working fluid are related to the contact surface condition,and the value of acc is significantly influenced by temperature.Therefore,the impact of different internal parameters and operating temperatures on acc of sodium within the sodium heat pipe was studied by using experimental methods.By varying parameters such as heating power,inclination angle,filling ratio,and capillary wick,the axial outer wall temperature and internal vaporphase temperature under steady-state conditions were measured using the thermocouple placed on the outer wall and the radially movable thermocouple inside the heat pipe.The experimental results reveal that the vapor-phase temperature distribution is non-uniform in the radial direction on steady-state condition,exhibiting a certain thermal gradient.Different methods for selecting vapor temperatures,in combination with measured outer wall temperature,were employed to derive the experimental values of acc under different work conditions and operating temperatures based on the Hertz-Knudsen-Schrage equation.Analysis demonstrates a good linear relationship between the logarithmic value of acc and the logarithmic saturation pressure within the sodium heat pipe,which remains consistent for different sodium contents and inclination angles.However,when using the wall temperature of the adiabatic section or the vapor-phase temperature of the adiabatic section as the vapor temperature,acc tends to be relatively small due to the influence of radial thermal resistance and the wetting properties of liquid sodium,particularly below the wetting t
作者
马在勇
周政
马誉高
吴奇
张卢腾
连强
唐思邈
潘良明
MA Zaiyong;ZHOU Zheng;MA Yugao;WU Qi;ZHANG Luteng;LIAN Qiang;TANG Simiao;PAN Liangming(Key Laboratory of Low-grade Energy Utilization Technologies and Systems,Ministry of Education,Chongqing University,Chongqing 400044,China;Department of Nuclear Engineering and Technology,Chongqing University,Chongqing 400044,China;Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu 610213,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2024年第10期2106-2112,共7页
Atomic Energy Science and Technology
基金
国家自然科学基金(12305174,12305194)
核反应堆系统设计技术重点实验室基金(301014002018-05-FWHT-WU-2023001)
中国博士后科学基金(2023M730397)。
关键词
钠热管
蒸发调节系数
实验研究
模型开发
sodium heat pipe
evaporation accommodation coefficient
experimental study
model development
