Fabrication of form stable composite phase change materials for thermal energy storage by direct powder incorporation with a preheating process

This work concerns with form stable composite phase change materials (FSCPCMs) for thermal energy storage applications. A vast knowledge base has been established in formulation design, material selection and characterisation. However, research efforts on manufacturing technologies are insufficient, leading to limited information on the relationship between manufacture processes and product properties - the main motivation for this work. A commonly used fabrication method is the so-called direct powder incorporation method. We have modified the direct incorporation method by the integration of a preheating process and used the modified method to fabricate a KNO₃-diatomite based FSCPCM. The characterisation of the fabricated FSCPCMs showed that the preheating method not only densified the microstructure, but also gave a significant increase in the thermal conductivity (by 54.91%). The improvements were found to be associated with wettability of the PCM on the matrix surface, whereas porous structure of the matrix material has a small effect.