Modelado matemático y simulación de la transferencia de calor en un lecho fijo para el núcleo del reactor nuclear “Fixed bed nuclear reactor (FBNR)”

Abstract

The FBNR reactor constitutes an innovative reactor that bases its operation on this type of structure. Within the study of fixed beds it is important to define the minimum refrigerant flow, the configuration of the fuel elements that make up the bed, the pressure profile in the bed, the profile of the temperature of the coolant and the fuel elements, the parameters. It is of relevant importance to ensure that the thermal limitations of the materials involved in the core and fuel are not exceeded. In order to determine the parameters required for a steady state, a computational bed model was developed in the Comsol Multiphysics software, and Heat combined heat transfer and flow and transfer modules were used. The results of the simulation were validated using a comparison with the data of the theoretical model of heat transfer, which is based on a balance of energy in the bed when considering the fuel spheres as a source of energy generation. A BCC structure was obtained as the best bed configuration, since under this safe operating conditions the optimum refrigerant flow velocity was 0.6 m/s. The selection was made based on the comparative analysis of parameters and due to the ease of construction.