Numerical Investigation for the Discharging Process in ColdWater Storage Tank

Thermal Energy Storage technology is used typically in industries and buildings for the thermal energy reservation in order that the stored energy can be used later. Numerical analysis was performed to study the thermal energy storage tank using Ansys CFX. In this paper, the unsteady discharging process was studied with two values of water flow rate. The model was simulated with two diffusers at the top and the bottom of the tank. The point of this research was to reduce the turbulence in the tank and the thermocline thickness. Results indicated that the thermal stratification improves with low inlet velocity, and high temperature difference, while the storage mixing increases by enlarging the inlet water flow rate. Then again, the inlet flow rates can be enlarged, without the increase of the mixing, beyond the thermocline has been formed. Again, thermoclines can be formed between the high temperature differences and varied with the variation in flow rate. In addition, large thermocline thickness between the water layers stored in the tank and the inlet water reduces the mixing due to the high difference in the density between the layers also high inlet water velocity results in increasing the mixing of water.