Polyoxyethylene based phase change materials with enhanced mechanical property, thermal conductivity and photo-thermal energy charging capacity

Abstract

Phase change materials are widely used as the thermal capacitors in solar thermal systems. For solar thermal utilization, the phase change materials should have large enthalpy, thermal conductivity, good mechanical property and photo-thermal performance. Polymer based phase change materials usually have good mechanical property. In this paper, we first using polyolefin elastomer to prepare a phase change material satisfied above properties. In addition, the mechanism of photo-thermal conversion of phase change materials is rarely reported. Here, the photo-thermal energy charging rate and photo-thermal efficiency of phase change materials are investigated with a combined numerical and experimental method. The effect of mass fraction, solar concentration and phase change materials height is systematically evaluated. The phase change composite has melting enthalpy of 126.7J⋅g−1, thermal conductivity of 1.413 W⋅m−1⋅ K−1, and photo-thermal efficiency of 58.2%. This work not only provide a method to prepare a phase change material with great photo-thermal performance, but also provide a sight to design the phase change materials for solar thermal utilizations via numerical results.