Summary
With the increasing global energy tension, how to effectively use energy has become a hot topic of current research. Inorganic hydrated salt phase change materials (PCMs) have been widely studied as heat storage materials with excellent properties. In this paper, sodium phosphate dibasic dodecahydrate (Na2HPO4∙12H2O), which has a large latent heat of phase change and stable thermal properties, was selected as the research object. The supercooling of sodium dibasic phosphate dodecahydrate was reduced by adding 1% graphene microsheets (GN) while improving the thermal conductivity. The thermal properties of Na2HPO4∙12H2O/GN composites were tested by differential thermal scanning calorimetry. Subsequently, the Na2HPO4∙12H2O/GN composite was added to the wall as a phase change layer for simulation experiments. Through the corresponding experimental analysis, the temperature regulation of PCM wall and ordinary wall under different conditions was compared. The results show that the cooling rate and heat velocity of PCM wall are 39.41% lower than that of ordinary wall, and the heat rate is 27.83% lower than that of ordinary wall. The test results show that the wall using Na2HPO4∙12H2O/GN as the phase change heat storage layer can effectively regulate the indoor temperature.
conclusion
Na2HPO4∙12H2O has the advantages of low cost and good thermal performance, and is suitable for popularization and application. The experimental results show that the addition of 1 wt% GN effectively improves the exothermic efficiency of Na2HPO4∙12H2O and reduces the subcooling to 1°C. According to the DSC analysis, the phase transition temperature of Na2HPO4∙12H2O/GN is 34.2°C and the latent heat of phase change is 232 J/g. After 20 thermal cycle tests, the Na2HPO4∙12H2O/GN composites remained stable. PCM walls can effectively reduce temperature fluctuations. This paper provides an experimental basis for the practical promotion and application of Na2HPO4∙12H2O.
