Fabrication and characterization of CaCl2·6H2O composite phase change material in the presence of CsxWO3 nanoparticles

Phase change materials (PCMs) with excellent energy conservation performance have been extensively utilized in solar energy storage system . In this study, a novel kind of thermal storage composite material based on calcium chloride hexahydrate (CaCl 2 ·6H 2 O) salt hydrate as core PCM and cesium tungsten bronze (Cs x WO 3 ) nanoparticles as near-infrared (NIR) light absorbent additives is fabricated. The effect of Cs x WO 3 nanoparticles on crystalline morphology, thermal physical behaviors and light transmittance of CaCl 2 ·6H 2 O are investigated. Additionally, thermal cycle tests are conducted for stability examination. Furthermore, thermal regulating performance of double layer glass window filled with the PCM composite is tested in small chambers by being sunlight irradiated under a solar simulator . All results manifest that with the incorporation of Cs x WO 3 nanoparticles, the salt hydrate PCM composite exhibits large latent heat, low supercooling degree and high NIR light shielding ability as well as good thermal stability . When employed as the glazing window of a test room, the PCM panel has functions of reducing indoor temperature fluctuations and increasing thermal inertia. Hence, the salt hydrate/nano Cs x WO 3 PCM design in this work shows great potentials for the development of solar energy storage products in energy conservation fields.