添加膨胀石墨的二十二烷-十二醇复合定形相变材料的性能研究  

Properties of composite shape-stabilized phase change materials incorporating docosane and dodecyl alcohol with added expanded graphite

作　　者：陈红兵 刘宇航[1,2] 王聪聪 李璊 张岩 卢浩阳 李春阳[1,2] CHEN Hongbing;LIU Yuhang;WANG Congcong;LI Men;ZHANG Yan;LU Haoyang;LI Chunyang(School of Environmental and Energy Engineering,Beijing University of Civil Engineering and Architecture,Beijing 102616,China;Beijing Municipal Key Laboratory of HVAC,Beijing University of Civil Engineering and Architecture,Beijing 100044,China;Beijing Heat Supply Company Shijingshan Branch,Beijing 100040,China)

机构地区：[1]北京建筑大学环境与能源工程学院,北京102616 [2]北京建筑大学供热、供燃气、通风及空调工程重点实验室,北京100044 [3]北京市热力集团有限责任公司石景山分公司,北京100040

出　　处：《储能科学与技术》2024年第2期396-404,共9页Energy Storage Science and Technology

基　　金：国家重点研发计划“临时结构低碳供热保温与通风关键技术”(2021YFF0306305-01)。

摘　　要：针对于太阳能PV/T系统相变材料热导率低、易泄漏的问题,本工作制备了二十二烷-十二醇/膨胀石墨复合定形相变材料并对其性能进行实验研究。本工作首先按照6∶4的比例制备了二十二烷-十二醇相变材料,然后采用熔融共混法制备了一系列膨胀石墨含量不同的复合定形相变材料。实验借助场发射扫描电子显微镜观察其微观结构,利用热流型差示扫描量热仪、热导率测量仪等仪器测量其潜热、热导率等参数,研究了材料的物理相容性、吸附性、循环稳定性,探究了膨胀石墨和二十二烷-十二醇的最佳配比及其各项性能。结果表明,当膨胀石墨质量分数为15%时,复合定形相变材料性能最佳,此时膨胀石墨足以将相变材料吸附,渗漏率仅为3.85%且无明显渗出,其熔化和凝固相变潜热分别为203.8 kJ/kg和-196.6 kJ/kg;在经过50次冷热循环后,其相变温度及潜热变化较小,热导率基本保持稳定,波动幅度仅为5.9%,质量损失较少,仅为0.0495 g,表现出良好的循环稳定性。研究为后续定形相变材料在太阳能PV/T系统中的应用提供理论数据支撑。In addressing the problems of low thermal conductivity and susceptibility to leakage in phase change materials within solar photovoltaic thermal(PV/T)systems,composite shape-stabilized phase change materials comprising docosane-dodecanol and expanded graphite were prepared and their properties were experimentally studied.Herein,docosane-dodecanol phase change materials were prepared in the ratio of 6∶4,followed by the preparation of a series of composite shape-stabilized phase change materials with different expanded graphite contents through a melt blending method.In the experiment,the microstructure was observed using field emission scanning electron microscope,and various parameters such as latent heat and thermal conductivity were measured using a heat flow differential scanning calorimeter and a thermal conductivity measuring instrument,respectively.The physical compatibility,adsorption,and cycle stability of the material were also studied.The optimum ratio of expanded graphite and docosane-dodecanol and its various properties were explored.The results show that the composite shape-stabilized phase change material exhibits optimal performance when the mass fraction of expanded graphite is 15%.At this composition,the expanded graphite is sufficient to adsorb the phase change material,resulting in a permeability of only 3.85%with no noticeable exudation.The latent heat of melting and solidification phase change is 203.8 and 196.6 kJ/kg,respectively.After 50 cooling and heating cycles,minimal changes are observed in phase transition temperature and latent heat,and the thermal conductivity remains stable with a fluctuation range of only 5.9%.Additionally,the mass loss is only 0.0495 g,which shows good cycle stability.This research provides valuable theoretical data support for the subsequent application of shaped phase change materials in solar PV/T systems.

关 键 词：二十二烷-十二醇 膨胀石墨 复合定形相变材料 物理相容性 吸附性 循环稳定性 

分 类 号：TB34[一般工业技术—材料科学与工程]