基于辐射-对流-传导热流固耦合模型的乏燃料贮运容器传热特性与优化研究

Study on Heat Transfer Characteristics and Optimization of Spent Fuel Storage and Transportation Containers Based on Heat-Fluid-Solid Coupled Model for Radiation,Convection and Conduction

基于辐射-对流-传导的热流固耦合计算流体动力学(CFD)模型,对比不同放置状态、环境温度、容器内部填充介质和有无环形翅片情况下,各部件最高温度、自然对流流速、外表面辐射及对流功率的变化。结果表明,水平放置有利于强化环形翅片的对流传热;环境温度每升高10℃,燃料包壳温度增加6.5℃,外壁面温度增加8.3℃;燃料篮内部填充物由中子吸收板或铝块更换为氦气后,容器整体导热性能明显降低,容器内部温度升高,但容器壁面温度基本不变;如不考虑太阳暴晒,环形翅片可增加对流传热,使得容器整体温度降低;如考虑太阳暴晒,环形翅片会增加太阳暴晒能量的吸收,使容器整体温度反而比光滑壁面容器高;基于代数分析法和漫灰表面模型对CFD辐射模型进行验证,CFD辐射功率和公式法计算结果基本一致。

Based on the heat-fluid-solid coupled computational fluid dynamics(CFD) model for radiation,convection and conduction, this paper compares the changes in maximum temperature,natural convection flow rate, outer surface radiation and convection power of various parts under different storage status and ambient temperatures, with different packing media in the containers,and with or without annular fin. According to the study results, horizontal arrangement improves the convection heat transfer on the annular fin;each time the ambient temperature increases by 10℃,the fuel cladding temperature and outer wall surface temperature increase by 6.5 ℃ and 8.3℃,respectively;when the medium filling the fuel basket is changed from neutron absorption plate or aluminum block to helium, the overall heat transfer capacity of the container deteriorates dramatically, with the temperature inside the container increasing and the outer wall surface temperature remaining almost unchanged;with the solar radiation ignored, a annular fin will help improve convection heat transfer and thus decrease the overall temperature of the container,otherwise, the annular fin absorbs more solar energy, causing the overall temperature of the container to exceed that of a container with smooth wall;and the CFD radiation power is basically same as the calculation results gained in the formula method, as shown in the verification of the CFD radiation model based on the algebraic analysis method and diffuse gray surface model.