Method for researching high Rayleigh number fusion pool heat transfer characteristics by moving particle finite volume method

Abstract

The invention discloses a method for researching high Rayleigh number fusion pool heat transfer characteristics by a moving particle finite volume method. The method comprises the following main stepsthat: 1: carrying out particle modeling by aiming at a specific problem, and setting a particle initial layout; 2: according to the position of each particle, dividing a grid; 3: after a time step length [Delta]t, using the finite volume method to solve an energy equation; 4: through a particle method, processing a viscosity term and a source term in an explicit calculation momentum equation, andestimating the speed and the position of the particle; 5: calculating particle number density, and solving a pressure Poisson equation; 6: calculating the correction value of the speed, and calculating the speed and the position of each particle in a next time level; and 7: outputting a calculation result, and according to a solved specific problem, outputting wall surface heat flux density and the phase state of substances in a fusion pool. The method has the advantages that a free liquid surface is accurately captured by a particle method and a phase change problem is simulated, and calculation accuracy is high. Through the method, the high Rayleigh number fusion pool heat transfer characteristics are researched, and an important basis is provided for researching the safety characteristics of the serious accident of a nuclear power plant reactor.

Description

technical field [0001] The invention relates to the technical field of research on heat transfer characteristics of head melting pools under severe accidents in nuclear power plants, in particular to a method for studying heat transfer characteristics of high Rayleigh number melting pools by using the finite volume method of moving particles. Background technique [0002] When a serious accident occurs in a nuclear power plant pressurized water reactor, if the core cannot be effectively cooled, the temperature will rise rapidly, causing a large number of fuel assemblies and structural materials to melt and migrate to the bottom of the pressure vessel, and the high-temperature melt entering the lower head will gradually accumulate A debris bed or melting pool is formed, which continuously transfers decay heat to the wall of the lower head. When the decay heat cannot be fully exported, the melting pool will heat the wall of the lower head to a very high temperature, seriously t...

AI Technical Summary

Problems solved by technology

Although the particle method has its unique advantages in dealing with fluid flow and phase transition problems, when the particle method calculates the heat transfer problem, there is a large error at the boundary of the calculation domain because the support domain is truncated.

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