Enhanced Temperature Stratification with Deflectors Laid within the Horizontal Water Storage Tank

Abstract

In the passive solar water heater, temperature stratification is a valuable thermodynamic parameter for horizontal water storage tanks. This investigation aims to optimize the deflector and numerically study the effects of various deflector lengths and materials on temperature stratification of a horizontal water storage tank during natural convection. Firstly, comparative thermal performances of the tanks with various deflector lengths are studied through a computational fluid dynamics solver. The cases are: 100 mm, 200 mm, and 300 mm long deflectors. It is found for the tank with 300 mm long deflector, Stratification number is increased by 3.49% and 32.96% compared to the tank with 100 mm long deflector or 200 mm long deflector, respectively. The 100 mm long deflector or 300 mm long deflector has a negative effect on the thermal efficiency. Secondly, the temperature stratification of the tanks with various deflector materials are investigated. The materials are Aerogel, Polymethyl methacrylate, and Stainless steel. It is found that among the tanks with various deflector materials, the tank with an Aerogel deflector has the best temperature stratification. In summary, the tank with a 300 mm long Aerogel deflector is the good structure optimization and is beneficial to strengthen temperature stratification of a horizontal water storage tank.