摘要
本文研究了储能材料CaCl_2·6H_2O-Ca(NO_3)_2·4H_2O的储能性能,并对影响其储能性能的结晶过冷问题和盐水分离问题进行了详细研究。发现单组分成核剂SrCl_2·6H_2O、BaCO_3、BaCl_2对该体系的过冷问题改性效果较好,能使熔盐的过冷度降低到2.3℃左右;增稠剂羧甲基四乙酸钠(CMC)对盐水分离问题有一定的改善,但会增大熔盐的过冷度。混合成核剂SrCl_2·6H_2O(2%)+BaCl_2(1%)+CMC (0.5%)对熔盐过冷问题改性较好,可使过冷度降低到1.8℃左右。储能材料改性前后相变焓变化不大,均在140J/g左右。在此基础上研究了熔盐CaCl_2·6H_2O和Ca(NO_3)_2·4H_2O的微观存在形式,从微观结构方面对熔盐存在的过冷和盐水分离问题进行了初步讨论。
The energy storage property of CaCl2·6 H2O-Ca(NO3)2·4 H2O composites salt system with their supercooling and brine separation problems were investigated in this work. It shows that the single nucleating agent SrCl2·6 H2O, BaCO3 and BaCl2 display a high effectiveness to reducing the supercooling to ~2.3℃. The thickening agent carboxyl methyl cellulose(CMC) has some effect on reducing the salt-water separation phenomenon, but it may enlarge the supercooling. The mixture nucleating agents with 2% SrCl2·6 H2O, 1%BaCl2 and 0.5% CMC are most suitable for this system with the supercooling reduction of ~1.8℃. The latent heat remained constant at about 140 J/g before and after adding the agents. The reason for the salt-water separation and super cooling phenomena were further investigated in microstructure aspect. It will offer a theoretical meaning for wide application of PCM of calcium-based hydrated salts at room temperature.
作者
周红霞
朱发岩
房文超
周永全
刘红艳
房春晖
房艳
ZHOU Hongxia;ZHU Fayan;FANG Wenchao;ZHOU Yongquan;LIU Hongyan;FANG Chunhui;FANG Yan(The mechanical engineering college of Qinghai University,Xining 810005,China;Laboratory of Salt Resources and chemistry,Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,China)
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2019年第1期153-160,共8页
Journal of Materials Science and Engineering
基金
青海省青年基金资助项目(2015-ZJ-938Q)
青海大学青年基金资助项目(2015-QGY-7)
关键词
储能材料
过冷问题
熔盐结构
拉曼光谱
密度泛函理论
energy storage materials
supercooling problem
molten salt structure
raman spectrum
density functional theory
