PCM, solar thermal, laminated film, supercooling
The research has explored a use for Tetra pack waste, while addressing an energy storage need. One class of phase change materials (PCMs) for low temperature heat storage, called supercooled salt hydrates, produces a room temperature, metastable liquid state enabling long-term heat storage, which must be seeded to trigger nucleation. However, the deployment of these PCM heat storage systems is limited by the availability of optimized technical packaging that can both contain the PCM and promote high rates of heat transfer. Lane (1978, 1980, 1985) reported promising results using laminated film packaging, composed of plastic and aluminium foil. Conformity of these materials to the expansion/contraction of phase change is very attractive and so is the impermeability to water and air. Even more promising is the presence of high thermal conductivity of the aluminium foil core that can carry heat further into the length of the package from a finite heat source. Packaging materials such as aseptic cartons, e.g. Tetra Brick, contain these types of materials and are otherwise discarded after use, while recycling is limited. This research intends to evaluate the heat transfer performance of candidate waste laminates, mainly from aseptic cartons, for recovery as innovative salt hydrate PCM packaging.