Numerical investigation of sand-basalt heat storage system for beam-down solar concentrators

Abstract

Abstract This study aims to investigate the performance of a novel combined receiver storage system (RSS) for beam down solar concentrator. The proposed system consists of large sand volume located at the ground underneath the secondary reflector of the beam-down tower. The top of the storage volume is covered by an absorber system which contains a thick black painted metal plate. The absorber plate absorbs the reflected solar flux and converts it to heat. The heat energy is then transferred to the storage media using metal rods. The performance of the thermal storage material of different mixing ratios of sand and basalt are investigated. The unsteady governing equations for the system are solved using a finite element heat transfer model. The model is validated and used to predict the temperature distribution inside the storage media of different conducting rods configurations. The utilization factor of the storage media for various cases is calculated and documented. The results showed that the utilization factor is in the range 0.53–0.73 depending on the conductive rods configuration and the sand – basalt mixture ratio.