MWCNTs-PEG/HFS复合相变材料的制备及其对水泥板热性能的影响

The preparation of MWCNTs-PEG/HFS composite PCMs and its effect on thermal property of cement board

以聚乙二醇(PEG)为相变材料、亲水性气相SiO2(HFS)为定形载体、多壁碳纳米管(MWCNTs)为导热填料,通过溶胶-凝胶法制备出新型MWCNTs-PEG/HFS复合相变储热材料,并采用比表面积及孔径分析仪、导热系数测试仪、扫描电子显微镜、差示扫描量热仪对其微观结构、导热特性、储热特性进行测试与表征。将MWCNTsPEG/HFS复合相变材料掺入水泥基材料中制备出复合储热水泥板,考察了MWCNTs-PEG/HFS复合相变材料掺杂量对水泥板导热系数及储热调温性能的影响。结果表明:MWCNTs-PEG/HFS复合相变材料具有较高的导热系数及较优的相变储热能力;复合相变材料增大了水泥板内部结构的孔隙率,因而对复合储热水泥板的导热特性造成不利影响。此外,ANSYS有限元分析软件的模拟分析结果表明,MWCNTs-PEG/HFS复合相变材料掺入水泥板后,能够发挥储热调温的作用,进而改善水泥板的热性能。

MWCNTs-PEG/HFS composite phase change thermal storage material was prepared by sol-gel method using polyethylene glycol(PEG)as phase change material(PCMs),hydrophilic SiO2(HFS)as the setting carrier and multi-walled carbon nanotubes(MWCNTs)as thermal conductive fillers.The microstructure,heat storage performance and conductivity of MWCNTs-PEG/HFS composite PCMs were characterized by specific surface area and pore size analyzer,thermal conductivity tester,scanning electron microscope and differential scanning calorimeter.By blending MWCNTs-PEG/HFS PCMs with ordinary portland cement,the novel heat storage cement boards were prepared,and the thermal conductivity and heat storage performance were tested.The results shown that MWCNTsPEG/HFS PCMs possessed higher thermal conductivity and better phase change heat storage capacity.The composite PCMs can increase the porosity of the internal structure of cement boards,which leaded to a reduction in thermal conductivity.Moreover,according to the simulation results of ANSYS finite element analysis software and practical test,the composite thermal storage cement board can storage heat,regulate temperature and save energy after adding MWCNTs-PEG/HFS PCMs.