Thermo-mechanical analysis of ceramic encapsulated phase-change-material (PCM) particles

Thermal energy storage (TES) is of growing importance, and involves the storage of both sensible and latent heat. Latent heat storage is particularly attractive, since it can store the energy as the latent heat of fusion at a constant temperature, thus providing a high energy storage density. The low temperature encapsulated phase change materials (PCM) in buildings have been extensively investigated mostly in rigid cells. The present paper studied the encapsulation of salts PCM material within elastic shells. The mechanical feasibility of such a spherical shell coating of a melting material is first investigated. The influence of encapsulation on the melting process of PCMs is thereafter studied for this particular geometrical case, including the complicated interactions with melting temperature of PCMs. The stored energy and pressure variation due to the volume change during the melting process are examined. It is shown that the encapsulated PCM particles can melt without cracking the coating shell only under specific conditions.