The Impact of Inlet Structure on Stratification Performance in Thermal Storage Tanks: A Study through Simulation and Experimental Analysis.

Featured Application: The elbow-type thermal storage tank is an innovative solution for thermal energy storage, with a uniquely designed bent pipe inlet structure that significantly increases hot water output and optimizes thermal stratification. This tank has demonstrated exceptional performance in reducing hot/cold water mixing and improving hot water availability. With its simple manufacturing process and easy installation, it not only meets users' demands for an efficient hot water energy-saving application but is also in line with modern environmental and energy-saving concepts. The elbow-type storage tank has a wide range of applications in areas such as energy-efficient air conditioning and residential buildings, offering a new approach to energy use. Thermal storage tanks are the most widely used devices for thermodynamic storage. Their stratification performance is a key factor in determining their effectiveness. In this study, a structure was proposed to improve the thermal stratification of an elbow-type thermal storage tank. An experimental study was conducted on its exothermic properties for applications in hot water storage tanks. An experimental analysis was performed to investigate the exothermic properties of the proposed structure, and the results were compared with those obtained from simulations using CFD (ANSYS 19.1) software. To investigate the effect of thermal stratification on the water inlet structure, the Richardson number, hot water output rate, and MIX number of the elbow inlet structure were compared with those of the water distributor inlet structure. The results show that the MIX numbers corresponding to the inlet structures of the two types of tanks, the elbow and water distributor types, are not very different. These values were almost identical to the Richardson numbers. Under the same working conditions, the hot water output rate was 84.90% for the elbow inlet structure and 76.39% for the water distributor inlet structure. In conclusion, elbow-type water inlet structures are easy to install, and the manufacturing process is simplified. [ABSTRACT FROM AUTHOR]