Research on preparation of nano-bismuth oxide-enhanced chloride/magnesium oxide composites and their thermophysical properties
In order to develop a low-cost,good thermal performance of the composite phase change heat storage material,NaCl,KCl,CaCl2 were used as phase change materials,MgO as carrier materials,and nano Bi2O3 as thermal conductivity en-hancers,chloride/magnesium oxide-based composite phase change thermal storage materials were prepared by mixed sinter-ing method.The chemical compatibility,microstructure,specific heat capacity and thermal conductivity of the chloride/mag-nesium oxide-based composite phase change heat storage materials by the thermal enhancer were tested and characterized by X-ray diffraction,scanning electron microscopy,synchronous thermal analyzer and DRL thermal conductivity.The re-sults showed that the thermal physical properties of the thermal enhancer nano-bismuth oxide were the best when the con-tent of 2%(mass fraction),the specific heat capacity was 1.16 J/(g·K),the heat storage density was 232.93 J/g,and the thermal conductivity was 1.61 W/(m·K).Compared with the addition of thermal conductivity enhancer,the specific heat ca-pacity was increased by 40%,the thermal conductivity was increased by 55%,and the heat storage density was increased by 9%.The prepared chloride/magnesium oxide composite phase change heat storage material always maintained a fixed form during use,the specific heat capacity and thermal conductivity were greatly improved,and it had good thermal stability at high temperatures.This study provided a low-cost and high-performance thermal storage material for the field of high-tem-perature thermal storage,which had broad application prospects in thermal energy storage systems.