Session: 03-02 Adv Reactors and Fusion

Paper Number: 64416

Start Time: August 5, 2021, 02:30 PM

64416 - Numerical Study on Multiscale Heat Conduction Problems in Very High Temperature Reactor Fuel Pebble Based on Openfoam 

Pebble bed very high temperature reactor (VHTR) has been identified as one of six Generation-IV (Gen-IV) types of reactor which could operate at a high thermal power. A typical VHTR core contains hundreds of thousands of centimeter-size fuel pebbles, each of which contains thousands of millimeter-size tristructural-isotropic (TRISO) fuel particles. The temperature distribution inside the fuel pebble is directly related to the safety and reliability of the whole reactor. Therefore, the calculation of the temperature in the fuel pebble is a key part of VHTR numerical simulation. However, due to the special structure of the VHTR fuel pebble, the temperature calculation involves a multiscale problem. The multiscale heat conduction model includes mesoscale temperature distribution of fuel pebble and microscale maximum temperature of TRISO fuel particles calculation. To deal with the particularity of temperature calculation of the fuel pebble, this paper presents a multiscale heat conduction model based on an open source CFD package OpenFOAM. OpenFOAM is a complete library for the finite-volume discretization and solution of partial differential equations, which makes it suitable for the development of the tool for multiscale heat conduction model. Firstly, the heat source decomposition method and quasi steady heat conduction method was verified by a simple multiscale model. The results show that the heat source decomposition method has a good ability of multiscale temperature prediction. Secondly, the mesoscale temperature distribution and the maximum temperature in the microscale of VHTR fuel pebbled are calculated with heat source decomposition method based on OpenFOAM. This multiscale solver will be couple with other solvers of OpenFOAM, to provide a new perspective of VHTR numerical simulation.

Presenting Author: Jincheng Wang College of Nuclear Science and Technology, Harbin Engineering University

Authors:

Jincheng Wang College of Nuclear Science and Technology, Harbin Engineering University
Ming Ding College of Nuclear Science and Technology, Harbin Engineering University