十二水硫酸铝铵-十水硫酸钠共晶复合相变材料的制备及其性能研究

Preparation and performance of ammonium aluminum sulfate dodecahydrate-sodium sulfate decahydrate eutectic composite phase change materials

针对单一水合盐相变材料相变温区适配性差,利用熔融共混法制备十二水硫酸铝铵-十水硫酸钠共晶复合相变材料,实现了单一相变材料的温度调控。共晶复合相变材料的相变温度为71℃,潜热值为242.85kJ/kg。采用质量分数为1%的氧化铝作为成核剂,复合材料的过冷度由9.4℃降低至2.5℃;添加高导热膨胀石墨提高材料的传热性能,复合材料的导热系数为原材料的1.73倍;改性后的复合相变材料循环稳定性显著提高,且储热释热密度为259.27kJ/kg。解决了单一十二水硫酸铝铵相变温度与供热末端所需温度不匹配的矛盾,制备的新型十二水硫酸铝铵-十水硫酸钠共晶复合相变材料具有合适的相变温度和较高的相变潜热,可作为以散热器为末端的供热系统、热水系统等领域的候选材料。

In response to the poor adaptability of phase change temperature region of single hydrated salt phase change material,the temperature regulation of single phase change material was achieved by preparing eutectic composite phase change material of aluminum ammonium sulfate dodecahydrate-sodium sulfate decahydrate using melt blending method.The phase change temperature of the eutectic composite phase change material was 71℃,and the latent heat value was 242.85kJ/kg.Using 1wt%alumina as nucleating agent,the supercooling degree of the composite was reduced from 9.4℃to 2.5℃.Adding high thermally conductive expanded graphite improved the heat transfer performance of the material,and the thermal conductivity of the composite was 1.73 times that of the raw material.The cyclic stability of the modified composite phase change material was significantly improved,and the heat storage and release density was 259.27kJ/kg.In this study,the contradiction between the phase change temperature of single ammonium aluminum sulfate dodecahydrate and the required temperature at the end of heating was solved,and the prepared new ammonium aluminum sulfate-sodium sulfate decahydrate eutectic composite phase change material had suitable phase change temperature and high latent heat of phase change,which could be used as a candidate material in the field of heating system and hot water system with radiator as the end.