利用膨胀石墨改进十二水磷酸氢二钠复合相变材料的蓄热性能  

Improvement of Heat Storage Performance of Disodium Hydrogen Phosphate Dodecahydrate Composite Phase Change Materials with Expanded Graphite

作　　者：王佩祥 冯秀娟[1] 朱易春[1] 蒋达华[1] WANG Peixiang;FENG Xiujuan;ZHU Yichun;JIANG Dahua(School of Architectural and Surveying&Mapping Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学建筑与测绘学院,赣州341000

出　　处：《材料导报》2020年第18期18044-18048,共5页Materials Reports

基　　金：国家自然科学基金(51364015)。

摘　　要：在十二水磷酸氢二钠(DHPD)中添加多孔网状膨胀石墨和九水硅酸钠制备得到复合相变储能材料。采用MLA650F电子显微镜、差示扫描量热仪、导热系数测量仪等器材对复合材料进行了结构观察和热性能测试,研究了膨胀石墨对DHPD热物性的影响。实验结果表明:添加4%(质量分数)的膨胀石墨可使DHPD的过冷度由14.3℃降至5.9℃,添加大于6%(质量分数)的膨胀石墨时能够消除DHPD的相分离现象,并且膨胀石墨能够大幅提升复合相变材料的导热率。复合相变蓄能材料较优的组成比例为6%EG+4%Na 2SiO 3·9H 2O+90%Na 2HPO 4·12H 2O,此时复合材料的相变潜热为220.6 J/g,相变温度为33.6℃,导热率为2.42 W/(m·K),过冷度为1.5℃,比纯DHPD过冷度降低了89.5%,导热率提升了3.4倍。冷热循环300次后,复合材料的相变潜热、导热率、过冷度等热性能稳定良好。The composite phase change energy storage material was prepared by adding porous expanded graphite and sodium metasilicate nonahydrate to disodium hydrogen phosphate dodecahydrate(DHPD).The effects of expanded graphite on the properties of DHPD were studied by using scanning electron microscope,temperature inspector,differential scanning calorimeter etc.The experimental results showed that when 4%expanded graphite was added,the supercooling degree of DHPD decreased from 14.3℃to 5.9℃,the phase separation could be eliminated and the thermal conductivity of composite phase change materials could be greatly enhanced when 6%expanded graphite was added.The optimal formula of compound phase change energy storage material was 6%EG+4%Na 2SiO 3·9H 2O+90%Na 2HPO 4·12H 2O,the latent heat of the phase-change material was 220.6 J/g,the phase transition temperature was 33.6℃,the thermal conductivity was 2.42 W/(m·K),and the supercooling degree was 1.5℃.Compared with pure DHPD,the supercooling degree decreased by 89.5%,and the thermal conductivity increased by 3.4 times.After 300 cycles of cooling and heating,the thermal performance of the composite material such as latent heat of phase change,thermal conductivity,and supercooling is stable and good.

关 键 词：相变 十二水磷酸氢二钠 膨胀石墨 过冷 蓄热 

分 类 号：TK02[动力工程及工程热物理]