A Study of Asymmetric Hyperbolic Heat Storage Unit

Due to the advantages of high energy density and constant temperature, phase change energy storage technology has attracted much attention in energy saving and efficient utilization of energy. In this paper, Fluent software is used to simulate and analyze the heat storage characteristics of six new thermal storage units: corrugated tube, hyperbolic-shape, non-hyperbolic-shape, symmetric frustum-shape, non-frustum-shape, and bow-shape. The results show that the melting rate of the non-hyperbolic-shape phase change unit is significantly higher than that of the circular tube, the heat storage time is shortened by 22.52%, and Ra* reaches 0.0086. Second, the effects of the radius difference (δ) between the inlet and outlet of the non-hyperbolic-shape phase change unit and the asymmetric position (s) on the heat storage process are studied. The results show that when δ increases from 2 to 10 mm, the melting time of phase change material (PCM) is shortened by 22.89%, that is, the average heat transfer rate between PCM and heat transfer fluid increases with the increase of δ. On the other hand, the average heat storage rate of the heat storage unit decreases first and then increases with the increase of s. When δ = 10 mm, s = 35 mm is the best working condition, the average heat storage rate of the non-hyperbolic-shape thermal storage unit reaches 34.3 J/s. This study can provide new ideas and references for the optimization design of latent heat storage units and the progress of experiments.