水合盐/膨胀石墨复合相变材料的热物性及循环稳定性研究  

Thermal properties and thermal cycling stability of hydrated salt/expanded graphite composite phase change materials

作　　者：刘云汉 王亮[2,3] 张双 林曦鹏 葛志伟[2] 白亚开 林霖 陈海生 LIU Yunhan;WANG Liang;ZHANG Shuang;LIN Xipeng;GE Zhiwei;BAI Yakai;LIN Lin;CHEN Haisheng(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Beijing 102206,China;Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206 [2]中国科学院工程热物理研究所,北京100190 [3]中国科学院大学,北京100049

出　　处：《储能科学与技术》2023年第12期3627-3634,共8页Energy Storage Science and Technology

基　　金：国家自然科学基金项目(51976217);中国科学院科学事业单位修缮购置专项资金仪器设备购置类项目(2021P173117000303);中国科学院先导科技专项(XDA29010300)。

摘　　要：本研究以三水合乙酸钠(SAT)作为主体相变材料,十二水合磷酸氢二钠(DSP)作为成核剂,羧甲基纤维素钠(CMC)作为增稠剂,膨胀石墨(EG)作为导热强化剂,采用熔融搅拌法制备了SAT-DSP-CMC/EG复合相变材料。通过扫描电镜、流变仪、天平、差示扫描量热仪、热常数分析仪等仪器对材料特性进行了表征和测量。通过热循环系统对材料的热循环稳定性进行了评估。结果显示,膨胀石墨可以提升复合相变材料的导热系数和黏度,但同时对复合相变材料的相变潜热和表观密度造成影响。随着膨胀石墨用量从1%增加至6%,复合相变材料的导热系数从1.055 W/(m·K)增长至2.247 W/(m·K),复合相变材料的表观密度从1.13 g/cm^(3)下降至0.77 g/cm^(3),复合相变材料的相变潜热从266.2 J/g下降至232.7 J/g。热循环实验表明,膨胀石墨用量为1%的复合相变材料具有良好的热循环稳定性,在530次热循环中,有效循环占比高于92%,过冷度普遍低于8℃。A composite phase change material(cPCM) was prepared in this study using the melt-blending method.It contained sodium acetate trihydrate as the main phase change material,disodium phosphate dodecahydrate as the nucleating agent,sodium carboxymethyl cellulose as the thickening agent,and expanded graphite as an additive to enhance thermal conductivity.The material properties were characterized and measured using a scanning electron microscope,rheometer,balance,differential scanning calorimeter,and thermal constant analyzer.The thermal cycling stability of the cPCM was evaluated using a thermal cycling system.The results demonstrated that expanded graphite enhanced the thermal conductivity and viscosity of the cPCM.However,it also affected the latent heat and apparent density of the cPCM.As the expanded graphite content increased from 1% to 6%,the thermal conductivity of the c PCM increased from 1.055 to 2.247 W/(m·K),the apparent density decreased from 1.13 to 0.77 g/cm^(3),and the latent heat decreased from 266.2 to 232.7 J/g.The thermal cycling experiments revealed that the cPCM with 1% expanded graphite exhibited excellent thermal cycling stability,with an effective cycle ratio of >92% and a low supercooling degree(generally <8 ℃) in 530 thermal cycles.

关 键 词：共晶水合盐 复合相变材料 膨胀石墨 热循环 

分 类 号：TK121[动力工程及工程热物理—工程热物理]