中高温复合相变储热材料的制备及性能研究

摘要

采用直接混合-压制-烧结工艺,制备了以碳酸钠-碳酸钾、碳酸钠-氯化钠、碳酸钠-氯化钠-氯化钾为相变材料的中高温复合相变储热材料.采用差式扫描量热法(DSC)、重量法和热循环法对中高温复合相变储热材料的相变峰值温度、相变潜热、热稳定性等性能做了表征.实验结果表明,以碳酸钠-氯化钠-氯化钾三元熔盐作为相变材料制备中高温复合相变储热材料,相变峰值温度为567℃,相变潜热高,是碳酸钠-碳酸钾二元熔盐的2.7倍,在750℃以下有较好的热稳定性,且具有较好常温力学性能.%Na2CO3-K2CO3,Na2CO3-NaCl and Na2CO3-NaCl-KCl based composite phase change heat storage materials (PCMs) for medium and high temperature applications were prepared.The performances,such as phase change peak value temperature,phase change latent heat,and thermal stability of composite PCMs were characterized by thermal gravimetrical analyzer,differential scanning calorimeter and thermal cycling device.The results showed that the ternary formulation of Na2CO3-NaCl-KCl had a peak phase change temperature of 567 ℃ with a latent heat of 2.7 times that of Na2CO3-K2CO3.This ternary composite PCM also had a good thermal cycling stability below 750 ℃,exhibiting an excellent mechanical strength.