Enhanced thermal performance of latent heat thermal energy storage systems with pulsating flow: A biomimetic approach inspired by alveolar vascular structures

This study addresses the limitations of shell-and-tube latent heat thermal energy storage (TES) units, namely low heat transfer efficiency and slow charging/discharging rates, by introducing alveolar vascular fins and pulsating flow. Numerical simulations were conducted to analyze the impact of pulsating flow parameters (period, amplitude, and temperature) on the melting/solidification process of the phase change material (PCM). The results show that pulsating flow significantly enhances convective heat transfer between the PCM and the heat transfer fluid (HTF), leading to shorter melting times. The average PCM temperature increases with increasing amplitude velocity, decreasing pulsating period, and increasing inlet temperature. To optimize TES performance, response surface method and the non-dominated sorting genetic algorithm II (NSGA-II) were employed. The study found that amplitude velocity had the greatest influence on TES heat transfer. Optimal values for heat storage, pressure drop, and melting time were determined to be 8.39 kJ, 22.87 Pa, and 309.82 s, respectively, corresponding to a pulse period of 12.26 s and an amplitude velocity of 0.139 m/s. This study sheds light on the mechanism by which pulsating flow enhances the heat storage performance of TES units, providing valuable insights into the heat transfer characteristics of phase change storage under pulsating flow.