Nuclear reactor plate fuel melting fluid-solid coupling meshless analysis method

Abstract

The invention relates to a nuclear reactor plate fuel melting fluid-solid coupling meshless analysis method. The method comprises the following specific steps: 1, carrying out initial modeling on a plate fuel under a Cartesian coordinate system; 2, searching neighbor particles by adopting a linked list method, and storing neighbor particle information in an array; 3, explicitly calculating a gravity item, a viscosity item and a surface tension item in the momentum conservation equation to obtain the estimated speed and position of the particles; 4, calculating heat transfer among particles, and judging the phase state of the particles by using an enthalpy value phase change model; 5, searching whether collision among solid particles exists or not, and performing calculation by using a DEM model; 6, implicitly calculating a pressure gradient item, and correcting the speed and position of particles; 7, outputting a required result, and advancing the time step until the simulation is finished. According to the method, all situations of melt fluid-solid coupling of the nuclear reactor plate-shaped fuel are considered, wherein the particle method can accurately capture the free liquid level of the melt, and the solid-liquid coupling model can analyze the action between the melt and fuel particles.

Description

technical field [0001] The invention relates to the technical field of research on the migration behavior of molten matter when the plate-shaped nuclear fuel in a severe accident of a nuclear power plant is melted, and in particular relates to a gridless analysis method for nuclear reactor plate-shaped fuel melting fluid-solid coupling. Background technique [0002] Compared with the rod-shaped fuel elements used in general nuclear power plants, the nuclear assembly composed of plate-shaped nuclear fuel pressed by dispersed particles has a more compact structure, and the fuel core has a larger heat transfer area, so the temperature is lower, and the heat transfer efficiency is higher. Because of its deep burnup and other characteristics, it is widely used in integrated reactors, nuclear power reactors and experimental research reactors. Under accident conditions, if the fuel element swells due to irradiation when the burnup is too deep, the coolant flow path will be narrowed...

AI Technical Summary

Problems solved by technology

In addition, since so far domestic and foreign researches have mainly focused on issues related to rod-shaped nuclear fuel, the behavior and mechanism of rod-shaped fuel elements under severe accidents have been deeply understood. The mechanism analysis program (such as: MELCOR and SCDAP / RELAP5, etc.) has obtained some more accurate simulation results for rod-shaped fuel element cores, but there are few studies on plate-shaped nuclear fuel elements at home and abroad, and the established models exist Relatively simple and rough problems, and the existing severe accident procedures cannot meet the needs of severe accident analysis of reactors using slab nuclear fuel

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