Multi-objective optimization of a latent thermal energy storage unit with compound enhancement method

The compound enhancement method shows excellent prospects for improving the heat transfer performance of phase change materials (PCMs) in recent years. This study intends to design and investigate an efficient latent thermal energy storage (LTES) unit with a novel combination of the heat pipe (HP), fins, copper foam, and nanoparticles. To explore the combination characteristics, a method that includes the multi-objective differential evolution (DE) algorithm, the response surface methodology (RSM), and conventional numerical simulations was developed. The optimization was carried out to minimize the phase change time and maximize the exergy conversion capacity. The results indicate that the fin radius and the porosity significantly affect the phase change time, while the PCM enclosure height and the PCM enclosure radius profoundly affect the exergy conversion capacity. The main and interaction effects of seven control parameters on the thermal characteristics were also investigated. The existence of some strong synergistic effects indicates that the appropriate values of the control parameters are crucial in designing the highly efficient LTES unit. Moreover, the Pareto front was displayed to prove the effectiveness of the multi-objective DE algorithm by achieving a reasonable balance between the two conflicting objectives.