Phase change behavior of latent heat storage media based on calcium chloride hexahydrate composites containing strontium chloride hexahydrate and oxidation expandable graphite

Calcium chloride hexahydrate (CaCl2 center dot 6H(2)O) composites PCMs containing strontium chloride hexahydrate (SrCl2 center dot 6H(2)O) and oxidation expandable graphite (EGO) were prepared and phase change behavior of CaCl2 center dot 6H(2)O/EGO/SrCl2 center dot 6H(2)O composite PCMs, including supercooling degree, phase change temperature, latent heat, density, thermal conductivity and thermal stability were systematically studied. Results demonstrate that thermal conductivity, heat transfer and the latent capacities of the CaCl2 center dot 6H(2)O/SrC12.6H20/EGO composite PCMs are significantly enhanced, supercooling of CaCl2 center dot 6H(2)O/SrCl2.6H(2)O/EGO composite PCMs are suppressed, mainly ascribe to that the EGO are homogenously dispersed in PCMs due to the existence of oxygen -containing functional groups in EGO, meanwhile, the well dispersed EGO serving as nuclei to promote the heterogeneous nucleation and crystallization process of CaCl2 center dot 6H(2)O. Moreover, a fifty -run -cycling test verifies that the CaCl2 center dot 6H(2)O/SrCl2.6H(2)O/EGO composites PCMs contained with 3 wt% SrCl2 center dot 6H(2)O, and 1.0 wt% EGO possesses enhanced thermal behavior with no phase segregation observed; the latent heat was calculated to be 172.26 Jig. (C) 2016 Elsevier Ltd. All rights reserved.