Optimal Design of High-Temperature Thermal Energy Store Filled with Ceramic Balls

Abstract

The momentary amount of the available solar energy and the demand usually are not equal during the usage of solar energy for heating and electric power supply. So it is necessary to store the heat energy. This article shows optimal design of a new construction, sensible heat store filled with solid heat storage material. The planned heat store has cascade system formed a spiral flow-path layout. This is a conceptual model, worked out in case of packed bed with ceramic balls. The aim of the special layout is to realize better overall efficiency than regular sensible heat stores have. The new construction would like to get higher overall efficiency by long flow-way, powerful thermal stratification and spiral flow-path layout which can ensure lower heat loss. The article shows the calculation method of the simulation of the charge and discharge and the calculation method of the overall efficiency using the results of the simulations. The geometric sizes and operating parameters of the thermal energy store with the best overall efficiency were calculated using genetic algorithm (GA). The results of the calculation tasks show that a thermal energy store with long flow-way, with cascade system formed spiral flow-path layout has higher overall efficiency than an one-duct, short flow-way thermal energy store which has equal mass of solid heat storage material as the long flow-way one, mentioned before.