Experimental investigation of effects of supercooling on microencapsulated phase-change material (MPCM) slurry thermal storage capacities

Ice storage is currently the dominant cooling energy storage method. To more effectively utilize natural, renewable cooling sources, such as evaporative cooling and sky-radiative cooling, diurnal storage media operated on a daily basis at the temperate range between 10 and 20 °C are the most desirable. This paper will present the experimental investigation of microencapsulated paraffin slurry as cooling storage media for building cooling applications. The water slurry of microencapsulated n-hexadecane with a melting temperature of 18 °C was cooled to 5 °C and heated to 25 °C cyclically in a storage tank of 230 l, and it was observed that full latent heat storage can only be realized at around 7 °C due to supercooling, and the effective cooling storage capacity at the cooling temperature range between 5 and 18 °C are obtained, which can be used to realistically estimate cooling storage capacity with various natural cooling schemes.