Development of modified disodium hydrogen phosphate dodecahydrate/vermiculite composite phase change material and its application in radiant heat storage panel system.

The integration of phase change materials (PCMs) with thermal energy storage capabilities in radiant heating systems can significantly enhance energy utilization efficiency and improve indoor thermal comfort. In our recent study, we developed a modified composite phase change material (CPCM) based on disodium hydrogen phosphate dodecahydrate (DHPD, Na 2 HPO 4 ·12H 2 O). This material was integrated into a radiant heating system and its thermal performance was evaluated in an experimental room. To address issues such as supercooling, liquid leakage, and the unstable morphology of DHPD, we selected appropriate nucleating agents and additives, combining them with vermiculite (VM) for adsorption. This led to the creation of a Modified DHPD/MVM CPCM with a melting point of 32.7 °C, a latent heat of 169.4 J/g, and a supercooling degree of 1.95 °C. The phase-change thermal storage module, prepared using a vacuum macroscopic encapsulation method, demonstrated good thermal reliability. Thermal performance tests indicated that the installation of phase change radiant heat storage panel effectively reduced fluctuations in ceiling and indoor air temperatures, extending the total indoor thermal comfort duration by an additional 5.7 h at a water supply temperature of 50 °C. This research offers valuable insights for the further development of phase change radiant heat storage technology. [ABSTRACT FROM AUTHOR]