改性CaCl_(2)·6H_(2)O混合相变蓄热材料的制备与特性  

Preparation and Properties of Modified CaCl_(2)·6H_(2)O Hybrid Phase Change Thermal Energy Storage Materials

作　　者：何媚质 杨俊玲[1] 杨鲁伟[1,2] HE Mei-Zhi;YANG Jun-Ling;YANG Lu-Wei(Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院理化技术研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《工程热物理学报》2021年第7期1676-1684,共9页Journal of Engineering Thermophysics

基　　金：国家自然科学基金(No.21606244)。

摘　　要：选用碳素材料(C)石墨(Gr)、石墨烯纳米片(GnPs)、多壁碳纳米管(MWCNTs)和SrCl_(2)·6H_(2)O(SCH)为改性剂添加至无机相变材料CaCl_(2)·6H_(2)O(CCH)中,制备出不同质量分数碳素材料的无机混合相变蓄热材料C/0.2%SCH/CCH,并表征混合相变材料性能。结果表明:混合相变材料液态导热系数随碳素材料质量分数增加均呈线性提高,其中2.0%石墨烯纳米片可将导热系数提高69.35%;XRD谱图表明碳素材料、SrCl_2·6H_(2)O和CaCl_(2).6H_(2)O之间的混合都为物理作用;DSC结果显示随碳素材料质量分数增加,相变潜热逐渐降低;质量分数4.0%Gr、2.0%GnPs和2.8%MWCNTs将0.2%SCH/CCH的放热时间分别减少了18.0%、41.9%和12.8%;4.0%Gr/0.2%SCH/CCH、2.0%GnPs/0.2%SCH/CCH和2.8%MWCNTs/0.2%SCH/CCH在经历100次加速热循环实验后,相变潜热分别降至186 J/g、189 J/g和183 J/g左右,仍满足蓄热要求,混合相变蓄热材料具有良好的热循环稳定性。Carbon materials(C)including graphite(Gr),graphene nanoplatelets(GnPs)and multiwalled carbon nanotubes(MWCNTs),and SrCl_(2)·6H_(2)O(SCH)were chosen to modify inorganic phase change material(PCM)CaCl_(2).6H_(2)O(CCH).The C/0.2%SCH/CCH hybrid PCMs were prepared by adding the carbon materials at different mass fraction and 0.2%SrCl_(2).6H_(2)Ointo CaCl_(2)·6H_(2)O.Thermal properties of the hybrid PCMs were determined by using differential scanning calorimetry(DSC)analysis,transient hot-wire method and T-history method.Besides,the crystalline structure of the hybrid PCMs was characterized by X-ray diffraction(XRD).The experimental results indicated that liquid thermal conductivity of the hybrid PCMs all increased linearly with the increase of carbon materials content.The thermal conductivity of 2.0%GnPs/0.2%SCH/CCH hybrid PCM significantly raised by 69.35%compared with that of 0.2%SCH/CCH.XRD spectra showed that the interaction between carbon materials,SrCl_(2).6H_(2)Oand CaCl_(2)·6H_(2)Owas physical.DSC analysis demonstrated that the phase change latent heat of the hybrid PCMs gradually decreased with the carbon materials increasing.4.0%Gr,2.0%GnPs and 2.8%MWCNTs reduced the heat release time of 0.2%SCH/CCH hybrid PCM by 18.0%,41.9%and 12.8%respectively.After 4.0%Gr/0.2%SCH/CCH,2.0%GnPs/0.2%SCH/CCH and 2.8%MWCNTs/0.2%SCH/CCH experiencing 100 accelerated thermal cycles,the corresponding phase change latent heat decreased to approximately 186 J/g,189 J/g and 183 J/g,which still met the requirements of heat storage.So,it could be concluded that these hybrid PCMs had good thermal cycling reliability.

关 键 词：CaCl_(2)·6H_(2)O 碳素材料 混合相变蓄热材料 热性能 相互作用 

分 类 号：TK02[动力工程及工程热物理]