CFD simulations of thermal stratification heat storage water tank with an inside cylinder with openings

This paper presents simulation of thermal stratification heat storage water tank with an inside cylinder with openings by three-dimensional Computational Fluid Dynamics (CFD) methods. Specifically, this paper focuses both on investigating the influence of the inner cylinder's design and operating parameters and on the water flow characteristic, thermal stratification and overall performance of the hot heat storage water tank during heat charging operation process installed in thermal energy systems. Validation of CFD results with experimental data found in the literature has a good consistency. In order to visually compare the efficiency of the energy storage tank with thermal stratification, and the dimensionless fluid temperature, one of existing methods for calculating stratification efficiencies is applied to hypothetical storage process of charging in this paper. Cylinder insides the tank plays a role of uniform diffuser, so that the water in the tank is formed thermal stratification. (C) 2016 The Authors. Published by Elsevier Ltd.