Heat storage in solar energy heating systems using phase change materials

Abstract

Irradiance of solar energy generally reaches its peak at mid-day, however, maximum thermal energy demand for room heating occurs at night, consequently storage of thermal energy in the heating systems using solar energy is imperative. Heat storage using phase change seems attractive. This enables to store a larger amount of energy in a smaller charge volume. Furthermore, the temperature of charge material during the process of phase charge remains almost constant. The advantages of heat storage using phase change were revealed when heat carrier was air. The objective of our study was to identify the thermal energy, which can be stored in the charge of calcium chloride hexahydrate capsules when air is used as heat carrier. Experimental tests were carried out. Experimental evidence suggests that when the temperature of charge of calcium chloride hexahydrate capsules varies from 15 to 33°C and the index of close-set of capsules is 30%, it accumulates 92.27 MJ of heat, calculated per one m³ of charge.