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

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.