EXPERIMENTAL AND NUMERICAL INVESTIGATION OF NOVEL DIFFUSERS FOR ENHANCED THERMAL STRATIFICATION IN TANKS

The efficacy of thermal energy storage systems is fundamentally dependent on maintaining thermal stratification within water storage tanks. This study scrutinizes how diffuser design impacts thermal stratification under varying flow rates. Specifically, we evaluate two diffuser models: a holed parallel plate radial diffuser (D-1) and a curved parallel plate radial diffuser (D-2). Utilizing an experimental setup with flow rates ranging from 5 to 8 liters per minute, complemented by Computational Fluid Dynamics simulations, our analysis reveals that the radial diffuser with a curved parallel plate (D-2) outperforms its holed counterpart (D-1) in sustaining a narrower thermocline and enhancing stratification. Notably, D-2 maintains a thermocline thickness of approximately 11.5 cm at an 8 L/min flow rate, compared to (D-1) 18 cm under the same conditions. This superior performance of D-2 is attributed to its ability to reduce mixing and turbulence within the tank, thereby optimizing the thermal efficiency of the storage systems.