An Adaptive Method of Expansion Order for Variational Nodal Method of Diffusion Equation

Abstract

An expansion order self-adaptive method of the variational segmental method of the diffusion equation, 1. Approximate the diffusion equation of the reactor core with a rough mesh finite difference, and then iteratively solve the rough mesh finite difference equation through the fission source to obtain the effective multiplication coefficient of the reactor and The average neutron flux density of each energy group of each node, and then obtain the differential approximate neutron flux density of each surface of each node; 2. The effective multiplication coefficient obtained in step 1 and a certain node The neutron flux densities of the left and right surfaces in a coordinate direction are respectively substituted into the coefficient matrix of the one-dimensional diffusion equation and the analytical expression, and the analysis of the neutron flux density distribution in the coordinate direction of the node under the current boundary conditions is solved. 3. Use the residual weight method to expand the analytical solution of the neutron flux density distribution obtained in step 2, and analyze the error of its expansion polynomial step by step, and then determine the neutron flux in the coordinate direction in the block The expansion order required to expand the density distribution within a certain error limit.

Description

technical field [0001] The invention relates to the technical field of nuclear reactor core design and reactor physical calculation, in particular to an expansion order self-adaptive method of the diffusion equation variational segmental method. Background technique [0002] In order to ensure the safety of reactor core design and operation, it is necessary to accurately and quickly calculate the distribution of neutron flux density in the reactor and related equipment. [0003] At present, the widely used method for calculating the neutron flux density distribution of reactors is the nodular block method, although the aberrant block method has the advantages of wide applicability, higher accuracy, and the fine distribution of neutron flux density can be obtained directly. However, the higher the expansion order in the variable block method is, the higher the calculation accuracy is, and the lower the calculation efficiency is, so in order to obtain higher accuracy, it is ne...

AI Technical Summary

Problems solved by technology

However, the higher the expansion order in the variable block method is, the higher the calculation accuracy is, and the lower the calculation efficiency is, so in order to obtain higher accuracy, it is necessary to use a higher expansion order for calculation, which makes Its computational efficiency is greatly reduced

Images