Heat transfer performance of paraffin as a phase change material (PCM) in a concentric annulus

In order to the investigate heat transfer enhancement in paraffin side, a heat transfer experimental setup was constructed. Heat transfer performance of thermal storage processes of paraffin PCM was studied using a constant temperature heat source as the heating medium. The relationships between Stefan number, thermal storage time, paraffin temperature and radial distance were also investigated. The result shows that heat transfer effect with a finned tube under conditions of heat conduction is better than that under conditions of convection. With heating medium temperatures of 65°C, 70°C and 75°C, compared the finned tube with the plain tube, thermal storage times of the finned tube are shortened by 77.5%, 69.2% and 56.3% respectively, demonstrating the beneficial effect of the fins on the heat transfer enhancement in the paraffin. In addition, the thermal storage time and the lapse rate of phase interface vary monotonically with Stefan number.