A new strategy for enhanced latent heat energy storage with microencapsulated phase change material saturated in metal foam

Traditional organic phase change materials (PCMs) possess the merits of high latent heat and chemical stability, but suffer from low thermal conductivity and volume expansion during phase transition. In this study, an enhanced energy storage technique with microencapsulated phase change material (MEPCM) saturated in metal foam is proposed to address these issues. The flow and thermal characteristics of MEPCM/foam under different foam geometries are experimentally extracted by means of comparing with two control groups, i.e., pristine PCM and PCM/foam modules. Particularly, the local thermal non-equilibrium effect between metal strut and MEPCM is analyzed. Results indicate that temperature reduction of 45 °C for heated surface is achieved by MEPCM/foam composite due to the thermal conductivity enhancement by metal foam. However, this better thermal control performance is obtained at the cost of shrinking the thermal management time. The natural convection of core PCM is suppressed in the MEPCM shell during/after the melting process. The thermal non-equilibrium is more pronounced inside MEPCM/foam than in PCM/foam module due to the contact thermal resistance between strut and MEPCM particle. Lower porosity composite has lower surface temperature attributed to the more dominant role of combined heat conduction.