Thermal performance enhancement of latent heat storage system using wavy fins and change in tube geometry

In this work, thermal performance improvement of the latent heat energy storage system using wavy fins and change in the heat transfer fluid tube geometry is numerically investigated. The investigated system is a shell and tube heat exchanger and RT35 paraffin is used as the phase change material. With the constant total cross-section area of the tube and fins as well as the volume of the phase change material, the effect of heat transfer fluid tube shape and the designed fin on the melting process of the phase change material is investigated. Numerical simulation results show that wavy fins accelerate the phase change process compared to conventional straight fins. The complete melting time of the phase change material is reduced by 9.33% compared to the straight fin. Changing the geometry of the heat transfer fluid tube from the circle to the petal shape is proposed to further improve the thermal performance of the latent heat energy storage system. The melting rate of the phase change material increases with the increase in the number of petals. The complete melting time for the tube with seven petals is reduced by 66.7% compared to the circular tube with wavy fins and 69.8% compared to the base case with straight fins.