Effective Cooling Storage Capacity Characteristics of Supercooled Phase-Change Materials for Building Cooling Applications

摘要

In the HVAC field, the mostly popular form of thermal energy storage for cooling is ice storage. To more effectively utilize natural, renewable cooling sources, such as evaporative cooling and sky-radiative cooling, diurnal storage media operated on daily basis at the temperate range between 10 and 20 °C are the most desirable. This paper will present our experimental investigation of microencapsulated phase change material (MPCM) slurry, the water slurry of microencapsulated n-hexadecane (CI6H34) with a melting temperature of 18 °C, as cooling storage media for building cooling applications. Supercooling of MPCM slurry is experimental investigated by DSC measurements and a small scale thermal storage test system. In the thermal storage test system, the MPCM slurry was cooled to 5 °C and heated to 25 °C cyclically in a storage tank of 230 litre with 3 stirring conditions, and it was observed the 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 between 5 and 18～C are obtained, which can be used for cooling storage system design with various passive cooling possibilities.