Pulsating flow and topology-optimized fin for improved heat storage performance in building heating systems

Phase change materials used in building thermal storage systems suffer from low thermal conductivity and slow heat storage rates. This study proposes a synergistic enhancement method combining topology-optimized fins with pulsating flow. The 3D numerical simulations and response surface method are employed to investigate the coupling effects of fin volume coefficient, pulsating velocity, amplitude, and period. The numerical model is validated against experimental data, showing an average error of 5.9%, which confirms its reliability. The NSGA-Ⅱ algorithm is used for multi-objective optimization. Increasing the fin volume coefficient from 0.05 to 0.15 reduces the complete melting time by 75.28%. The pulsation period has a limited effect, with less than 1.5% variation in thermal performance. The optimal parameter combination is a period of 10.23 s, an amplitude of 0.63 m/s, and a velocity of 1.29 m/s, yielding a thermal storage capacity of 194.23 kJ, an energy consumption of 0.72 W, and a complete melting time of 886.92 s. This study provides some reference for efficient phase change thermal storage systems in building heating applications.