Multi-objective optimization of rotating metal foam-enhanced PCM device for multi-scenario application

In the context of global energy transition, thermal energy storage technology plays a crucial role in enhancing the efficiency and stability of the energy system. Latent heat thermal energy storage technology offers advantages such as high energy storage density and small temperature variation. However, its low thermal conductivity limits its large-scale application. This study proposed a phase change heat storage unit structure that combines passive enhancement with active enhancement. Through numerical simulation, the effects of porosity (0.85–0.99), pore density (20–60 PPI), and rotational speed (0–1 rpm) on thermal performance were investigated. Response surface methodology was adopted to establish regression models correlating the influencing factors with energy, economic, and environmental indicators. Based on the NSGA-II algorithm, multi-objective optimization was carried out. Subsequently, combined with the AHP-entropy weight method, the weights were assigned, and the optimal structure was selected for multiple scenarios such as solar thermal storage, industrial waste heat recovery, and power peak shaving. The results indicate that low porosity and high rotational speed enhance the heat release rate. Specifically, a porosity of 0.85 combined with a rotational speed of 1 rpm reduces the solidification time by up to 13.72% compared to a stationary device, while stationary configurations with high porosity perform better in terms of economic and environmental indicators. The optimized structure obtained by this method exhibits excellent comprehensive performance in various application scenarios. A case study is conducted to validate the optimal structure for a solar thermal storage scenario (porosity 0.94, pore density 40 PPI, rotational speed 0.2 rpm), and the dynamic payback period is 8 years, with an annual electricity savings of 25,476 kWh and a CO₂ emission reduction of 820.24 kg.