Abstract: 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%Na2SiO3·9H2O+90%Na2HPO4·12H2O, 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.
1 Kan Rongqiang, Li Longjian, Cui Wenzhi, et al. Journal of Chongqing University of Technology (Natural Science), 2019, 33 (11),68(in Chinese). 阚荣强,李隆键,崔文智,等.重庆理工大学学报(自然科学),2019,33(11),168. 2 Yuan Y P, Zhang N, Tao W Q, et al. Renewable and Sustainable Energy Reviews,2014,29(7),482. 3 Sharma A, Tyagi V V, Chen C R, et al. Renewable & Sustainable Energy Reviews, 2009, 13(2),318. 4 Fu Yibo, Wang Dongmei, Zhu Hong. Materials Reports,2016,30(s2),222(in Chinese). 傅一波, 王冬梅, 朱宏. 材料导报, 2016,30(专辑28),222. 5 Nikolić R, Kelić K, Nešković O. Applied Physics A, 1984, 34(3),199. 6 Hirano S, Saitoh T S, Oya M,et al. Journal of Thermophysics & Heat Transfer, 2001, 15(3),340. 7 Miyasaka E, Takai M, Hidaka H, et al. Ultrasonics Sonochemistry, 2006, 13(4),308. 8 Rao Z H, Xu T T, Liu C Z, et al. Solar Energy Materials and Solar Cells, 2018, 188,6. 9 Tang Z W,Zhao H T,Cheng Z F. Journal of Beijing University of Techno-logy,2009, 35(6),809(in Chinese). 唐志伟, 赵化涛, 陈志锋. 北京工业大学学报, 2009,35(6),809. 10 Zhu P P,Huang J. Journal of Guangdong University of Technology,2014, 31(2),128(in Chinese). 祝盼盼, 黄金. 广东工业大学学报, 2014, 31(2),128. 11 Zhang X L,Sheng Q Q,Ge Y Q. Chemical Engineering,2009,3(5),53(in Chinese). 章学来, 盛青青, 葛轶群. 化学工程, 2009, 37(5),53. 12 Yan Y,Lin X H,Zhang H P. Journal of Chemical Engineering of Chinese Universities,2011,25(6),1068(in Chinese). 鄢瑛, 林小花, 张会平. 高校化学工程学报, 2011, 25(6),1068. 13 Chen Yue, Ji Jun, Xu Xiaofeng,et al. Chemical Industry and Enginee-ring Progress, 2018,37(7),285(in Chinese). 陈跃, 纪珺, 徐笑锋, 等.化工进展, 2018,37(7),285. 14 Huang Xue,Cui Yingde,Yin Guoqiang,et al. Materials Reports B: Research Papers,2017,31(7),52(in Chinese). 黄雪, 崔英德, 尹国强, 等. 材料导报:研究篇, 2017,31(7),52. 15 Tian H, Wang W, Jing D, et al. Applied Energy, 2015, 148,87. 16 Zhang Yinping, Hu Hanping, Kong Xiangdong, et al. Phase change sto-rage theory and application, University of Science and Technology of China Press, China, 1996(in Chinese). 张寅平, 胡汉平, 孔祥东, 等. 相变贮能——理论和应用. 中国科学技术大学出版社, 1996.