The energy storage characteristic analysis and optimization of latent heat energy storage component with finned tubes in building envelope

Abstract

This study numerically investigates the energy storage characteristic of the latent heat energy storage (LHES) component which can be used in building envelope. A simplified numerical unit is extracted from the component to analyze the effects of the style and ratio (0.5, 0.75, 1, 1.5) of fin and the inclination angle (45° and 90°) of the unit on melting at a constant tube temperature. The fin styles include cross shape (z style fin) and inclined cross shape (x style fin). Results show that the longer the fin, the faster the melting rate is. The temperature also changes more uniformly during melting. For the unit, z-1.5-90 (z style fin-fin ratio at 1.5-the inclination angle at 90°) presents the fastest melting rate and highest average energy storage power due to the division effect of fins. Therefore, the z-1.5-90 is used in the component and analyzed in the range of tube temperature at 55–80 °C. It is found that the average energy storage power of the component can reach up to 1567.37W, 4.05 times z-1.5–90 unit. An exponential relationship between the completely melting time and the tube temperature has also been found through curve fitting.