The Effect of Obstacle Geometry and Position on Thermal Stratification in Solar Hot Water Storage Tanks

Abstract

In this study the effect of obstacle geometry and its position on thermal stratification in solar powered domestic hot water storage tanks are numerically investigated. The goal of this study is to obtain higher thermal stratification and supply hot water for usage as long as possible. The temperature distributions are presented for three different obstacle geometries (1, 2 and 3) and six different distances (f = 0.3, 0.4, 0.5, 0.6, 0.7 and 0.8 mm) from the bottom of the hot water storage tank. The numerical method is validated using both experimental and numerical results available in the literature. It is observed from the results that the thermal stratification increases with the increasing obstacle distance from the bottom of the hot water storage tank for obstacle 1 and 3. The obstacle 2 provides less thermal stratification than the obstacles 1 and 3. As a result, in a duration of 30 minutes, the obstacle 3 provides the best thermal stratification for the distance of f = 0.8 mm from the bottom of the hot water storage tank.