Transient Analysis of Phase Change Material-Based Triple-Tube Unit with Sinusoidal Wavy-Shaped Fin.

Researchers have shown considerable interest in phase change material-based triple-tube units as a possible solution for storing and utilizing thermal energy. The uses of fins in the triple-tube unit were introduced by the researchers to address the low thermal conductivity of the phase change materials. In present study, the application of sinusoidal wavy-shaped fins in the phase change material (RT-82)-based triple-tube unit has been designed and a two-dimensional numerical model is developed for the transient analysis. The recharging–discharging of the phase change material are analyzed for configurations without fin, with conventional rectangular fins, and with sinusoidal wavy-shaped fins of varying amplitudes and numbers of peaks. The validation of the model was done against the experimental result of the published article. The thermal performance and fluid flow dynamics are quantitatively evaluated by analyzing the melt fraction, temperature, velocity and heat flux variation. The result shows that a conventional rectangular fin reduces the recharging–discharging time by 59.36% and 64.26%, respectively, when compared to without fins configuration. The use of sinusoidal wavy-shaped fins further reduces recharging–discharging times by 3.15% and 2.72%, respectively. When the amplitude of the sinusoidal wavy-shaped fins is increased, there is a significant improvement in the recharging–discharging process of the PCM. On the other hand, there is no significant effect when the number of peaks is increased. The pairs of cases with nearly identical PCM volume storage but different sinusoidal wavy-shaped fins configurations show significant variations in total recharging–discharging times. [ABSTRACT FROM AUTHOR]