Experimental Investigation on Ocean Thermal Energy Harvesting Using Phase Change Material and Metal Foam

Ocean thermal energy (OTE) is a clean, sustainable energy resource with large potential. Using volume change of the solid–liquid phase change material for OTE harvesting is a promising method to solve the energy limitation problem for underwater movable observation platforms. Metal foam is a widely used porous material to improve the heat transfer rate inside phase change material (PCM) and accelerate the phase change process. Because of their small size and lightweight, OTE can be harvested quickly in challenging conditions. In this work, thermal performance, including three parts: phase change time, volume change rate and phase change point, of phase change material embedded in metal foam was measured. In this study, we measured the thermal performance of PCM embedded in metal foam, encompassing two aspects: phase change time, and volume change rate. Results show that: (1) The back pressure is negatively related to phase change time, temperature difference between environment and phase change point is positively related to the phase change time; (2) Metal foam with low porosity will increase the phase change time but decrease the volume change rate of PCM.