A heat transfer model for volumetrically heated nuclear debris beds

Abstract

The thermal response of a fixed porous volumetrically heated debris bed is analyzed. The Modified Dispersion-Concentric Model (D-C model) is used in the analysis of forced flow cooling through a volumetrically heated fixed porous debris bed. The fundamental equations are based on the assumptions of dispersed plug flow and concentric intra-particle temperature profiles. The model is theoretically sound provided that a large axial effective fluid thermal dispersion coefficient is assumed. The fundamental equations are rather simple and can be easily solved in terms of temperature profiles for the solid and fluid phases. The theoretical model for the temperature profile for the fluid phase in the subcooled liquid region and in the superheated vapor region compares well with existing experimental measurements.