化工学报 ›› 2014, Vol. 65 ›› Issue (S1): 168-174.DOI: 10.3969/j.issn.0438-1157.2014.z1.027

• 流体力学与传递现象 • 上一篇    下一篇

遮光剂对气凝胶复合材料隔热性能的影响

方文振, 张虎, 屈肖迪, 何雅玲, 陶文铨   

  1. 西安交通大学热流科学与工程教育部重点实验室, 能源与动力工程学院, 陕西 西安 710049
  • 收稿日期:2014-01-28 修回日期:2014-02-10 出版日期:2014-05-30 发布日期:2014-05-30
  • 通讯作者: 陶文铨
  • 基金资助:

    国家自然科学基金项目(51136004,51276138);中国教育科研网格。

Influence of opacifiers on thermal insulation properties of composite aerogels

FANG Wenzhen, ZHANG Hu, QU Xiaodi, HE Yaling, TAO Wenquan   

  1. Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education, School of Energy & Power Engineering, Xi'an Jiaotong University, Xi'an 710049, Shaanxi, China
  • Received:2014-01-28 Revised:2014-02-10 Online:2014-05-30 Published:2014-05-30
  • Supported by:

    supported by the National Natural Science Foundation of China (51136004, 51276138) and ChinaGrid.

摘要: 纯气凝胶对近红外波长几乎透明,遮光剂的加入可以显著抑制气凝胶的高温辐射性能。采用Mie散射理论计算出掺杂不同种类、粒径遮光剂时复合气凝胶的平均消光系数,从而比较它们的遮光效果。采用基于瞬态平面热源法的Hot Disk TPS2500S导热仪测量了不同温度下复合气凝胶的热导率,获得了遮光剂对气凝胶复合材料隔热性能的影响规律,并与理论分析结果进行了对比。理论计算获得的不同温度下复合气凝胶的热导率与实验值符合良好,表明:在研究的范围内,掺杂的最佳遮光剂粒径在3.5 μm左右;SiC的遮光效果比TiO2、ZrO2好;存在一个最佳的遮光剂体积含量(3.75%左右)使得复合气凝胶的整体隔热性能最好;所建立的理论模型可用来预测掺杂遮光剂的影响规律。

关键词: 气凝胶, 遮光剂, 辐射, Mie散射, 瞬态平面热源法, 纳米多孔材料

Abstract: Aerogels are almost transparent to the near-infrared wavelengths, and therefore the opacifiers are widely doped to enhance aerogels insulation performances. Mie scattering theory was employed to calculate the mean extinction coefficient of composite aerogels doped with different kinds of opacifiers with different diameters and their shading effects were compared. A Hot Disk TPS2500S thermal analyzer based on the transient plane source method was used to measure the thermal conductivity of composite aerogels at different temperature and comparison with the theoretical analysis was conducted. The predicted thermal conductivities by theoretical model are in good agreement with the experimental data obtained by the Hot Disk thermal analyzer at different temperature. The results show that the optimal diameter of doped opacifiers is approximately at 3.5 μm, the shading effect of SiC opacifier is better than that of TiO2 and ZrO2, and there exists an optimal volume content of opacifiers (~3.75%) making the overall thermal insulation performance best. The developed theoretical model can be adopted to predict the influence of doped opacifiers on the effective thermal conductivity of composite aerogels.

Key words: aerogels, opacifiers, thermal radiation, Mie scattering, transient plane source method, nanoporous materials

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