基于网格变形法铅铋快堆组件堵流事故模拟

In LBE-cooled fast reactors, the fuel rod claddings or structural materials in the reactor will fall off due to corrosion of LBE. When corroded by LBE, which will block the coolant channel, cause local heat transfer deterioration and eventually lead to cladding failure. Therefore, it is necessary to analyze the flow and heat transfer characteristics in the assembly under the condition of blockage. The structure of wire-wrapped assembly is complex, and the unstructured grid division method has a large grid quantity, which requires high computing resources. In order to reduce the grid quantity, the mesh deformation method based on radial basis function is used to deform the grid of bare rod assembly, and the hexahedral grid with wire-wrapped assembly is obtained and numerical calculation is carried out. The calculated results of the hexahedral grid are in good agreement with the experimental data, and the grid quantity is much less than that of the unstructured grid, which can realize the rapid calculation of the blockage accident of wire-wrapped assemblies. Furthermore, calculations for two different types of blockages were performed in a typical wire-wrapped fuel assembly with 61 pins. The results show that for column-type blockage, the flow field recovers faster but with a higher local temperature rise; for plate-type blockage, the flow field recovers more slowly but the local temperature rise is small.