A novel stereotyped phase change material with a low leakage rate for new energy storage building applications

Phase change materials (PCM) have been widely studied in the field of building energy storage. However, industrial grade high latent heat phase change paraffin (PW) has the problem of high melting point and easy leakage, and at the same time, it is necessary to absorb municipal solid waste on a large scale and reduce the damage of waste cellular concrete (WCC) to the urban ecological environment. Using binary paraffin wax (BP) prepared by hot fusion of solid paraffin (SP) and liquid paraffin (LP) as composite phase change materials, polypropylene (PP) and porous material WCC as support materials, a new WCC/PP/BP stereotyped phase change material (FCPCM) with low leakage rate and good stability was prepared by melt blending method and vacuum adsorption method, to meet the energy storage needs of buildings. The chemical compatibility, thermal performance and morphological stability of the prepared FCPCM were tested, and the heat storage/release performance test experiments were carried out to explore the thermal performance of the prepared energy storage concrete. The results show that the Encapsulated WCC/PP/BP has no new substance and good chemical compatibility. The results of scanning electron microscope (SEM) and mercury injection instrument (MIP) show that WCC has good adsorption properties for PP/BP. The melting phase change temperature increases by 14.08%, the latent heat of phase change decreases by 42.94%, and the initial phase change thermal properties are still maintained after several phases of phase change. It can maintain a stable form at 150℃. The 24 h leakage rate remained below 1%, which was nearly 44% lower than that of FCPCM with PP as the support material. Thermogravimetric curve (TGA) shows that the thermal stability of encapsulated FCPCM increases by 25.59%. In addition, the thermal performance test of energy storage concrete shows that compared with traditional concrete, energy storage concrete has greater heat storage density and stronger temperature control ability, which can effectively realize building energy saving.