Thermodynamic and thermal energy storage properties of a new medium-temperature phase change material

Abstract

Phase change materials (PCMs) that can store the heat energy obtained from intermittent solar irradiation are very important for solar energy absorption cooling system. In this work, an organic compound that melts at the temperature of 368.2 ± 0.5 K was applied as PCM. The specific heat capacities of the PCM were measured by temperature-modulated differential scanning calorimetry from 198.15 to 431.15 K. The thermodynamic functions of [HT–H298.15] and [ST–S298.15] were then calculated based on the measured heat capacities data. Afterward, the long-term cyclic thermal energy storage stability and thermal stability of the PCM were investigated. The results show that the PCM melted and crystallized at about 368 and 364 K, respectively, with a phase change enthalpy (ΔtransH) of 21 kJ mol−1 (130 J g−1). Additionally, it exhibited good long-term cyclic thermal energy storage stability and thermal stability. Hence, the PCM could be applied as good PCM for solar energy absorption cooling.