Influence of inner tube shapes on the charging and discharging performance for the latent heat thermal storage exchangers

Changing the inner tube shape proves to be an effective method to enhance the efficiency of horizontal latent heat thermal energy storage exchangers (H-LHTES), which can improve the heat transfer efficiency of exchangers. This paper proposed an I-beam inner tube exchanger, which contained I-1 and I-2 types, then under the constant mass of phase change material, the charging and discharging performance of the H-LHTES with I-beam, circular, rectangular and rhombic inner tube shapes were comparatively investigated using FLUENT numerical simulation software. The results demonstrated that compared with the circular inner tube, the charging and discharging time reduces remarkably for the H-LHTES with I-beam, rectangular and rhombic inner tubes, and the I-beam inner tube shows the best enhancement effect, additionally, the I-1 has the shortest total time at the inner tube height of 74.8 mm, the charging and discharging time reduces by 82.41% and 43.56%, the total time decreases by 50.46%, the rectangular and rhombic inner tubes have the shortest total time at the inner tube height of 82.8 mm and 90.8 mm, the total time decreases by 34.7% and 36.99%, respectively. The results can supply a reference for the optimal design of inner tube shape of the H-LHTES.