Thermal stratification in a solar hot water storage tank with mantle heat exchanger

Abstract

Solar hot water storage tanks with mantle heat exchangers are widely used in balcony wall-mounted solar heating system in China. The thermal behaviour of a novelty mantle solar water tank with vertical inlet and outlet water tubes has been investigated both experimentally and numerically. Dimensionless parameter can well characterize the stratification of water and thermocline dynamics in the water tank. In the discharging mode, as the dimensionless time increases, the thermocline thickness gradually increases, and the mixing in the water tank intensifies. The dimensionless exergy gradually decreases with the increase of the dimensionless time.