Experimental analysis of parameters influencing thermal stratification in single media single tank storage system with flow distributor

Abstract

The design and operating parameters of a single media single tank (SMT) energy storage system affect the thermal stratification of the fluid. The objective of the present work is to propose a design configuration of an SMT to reduce the thermocline zone. To that end, experiments were performed to investigate the influence of the flow distributor, the fluid inlet, and outlet configuration on the thermal stratification. Experiments were also carried out to understand the scalability of the system. Results obtained from experiments performed for a range of Péclet numbers are analyzed using three performance parameters: the non-dimensional thermocline span ‘S’, mixing number Mix, and stratification number Str. The study shows that these parameters are scale-invariant. The result also shows that the use of a central flow distributor reduces the thermal gradient zone by 50% to 60% as compared to that achieved in a tank without the flow distributor operated with Péclet numbers between 262 and 945.