Numerical simulation of flow and heat transfer in fuel assembly of floating nuclear power platform

Floating nuclear power platform (FNPP), unlike onshore nuclear power plants, is subjected to periodic rolling loads at sea. These loads will have a more obvious impact on the flow characteristics and temperature distribution inside the fuel assembly (FA). This paper first establishes a refined model of the 7 x 7 core fuel assembly. Then, the flow and heat transfer characteristics of assembly with pure fuel bundles and assembly with guide tubes are analyzed using a segmented grid partitioning method, taking into consideration both accuracy and efficiency in calculation. Finally, the flow and heat transfer characteristics inside the assembly with guide tubes under rolling conditions are simulated and calculated, and compared with the previous simulation results. The calculation results show that the flow and heat transfer characteristics of the assembly with guide tubes are quite different from those of the pure fuel rod bundle assembly, and the rolling environment has obvious adverse effects on the flow field characteristics and temperature distribution in the fuel assembly of the offshore reactor, which must be considered in the design and construction of the floating nuclear power platform. The research results have significant reference value for the design and optimization of floating nuclear power platform assemblies under rolling conditions.