Numerical simulation of single media thermocline based storage system

Thermocline based single media tanks (SMTs) have emerged as a popular choice for storage of thermal energy in concentrated solar power plants. The motivation of the current work is to investigate the effect of various parameters on the thermocline thickness which decides the performance of SMTs. This paper presents a comprehensive analysis of the single media thermocline based thermal energy storage system through numerical simulations performed using COMSOL Multiphysics Two different fluids, i.e. water and molten salt are selected for the current analysis. Performance of SMT toward achieving the thermal stratification for different configurations and under various operating conditions is investigated. The results obtained from simulations are compared against the experimental observations. Simulations confirm that the vertical porous flow distributor eccentrically placed in the tank, helps in reducing the thermocline thickness. The results also suggest that the two non-dimensional numbers, i.e. the Peclet and the Atwood number have significant influence on the thermal stratification.