Properties of composite shape-stabilized phase change materials incorporating docosane and dodecyl alcohol with added expanded graphite
In addressing the problems of low thermal conductivity and susceptibility to leakage in phase change materials within solar photovoltaic thermal(PV/T)systems,composite shape-stabilized phase change materials comprising docosane-dodecanol and expanded graphite were prepared and their properties were experimentally studied.Herein,docosane-dodecanol phase change materials were prepared in the ratio of 6∶4,followed by the preparation of a series of composite shape-stabilized phase change materials with different expanded graphite contents through a melt blending method.In the experiment,the microstructure was observed using field emission scanning electron microscope,and various parameters such as latent heat and thermal conductivity were measured using a heat flow differential scanning calorimeter and a thermal conductivity measuring instrument,respectively.The physical compatibility,adsorption,and cycle stability of the material were also studied.The optimum ratio of expanded graphite and docosane-dodecanol and its various properties were explored.The results show that the composite shape-stabilized phase change material exhibits optimal performance when the mass fraction of expanded graphite is 15%.At this composition,the expanded graphite is sufficient to adsorb the phase change material,resulting in a permeability of only 3.85%with no noticeable exudation.The latent heat of melting and solidification phase change is 203.8 and 196.6 kJ/kg,respectively.After 50 cooling and heating cycles,minimal changes are observed in phase transition temperature and latent heat,and the thermal conductivity remains stable with a fluctuation range of only 5.9%.Additionally,the mass loss is only 0.0495 g,which shows good cycle stability.This research provides valuable theoretical data support for the subsequent application of shaped phase change materials in solar PV/T systems.
国家科技期刊平台
NSTL
万方数据
维普
