EXPERIMENTAL DETERMINATION OF THERMAL CONDUCTIVITY OF SILICA AEROGEL AND TWO COMPOSITE NANO-POROUS INSULATION MATERIALS WITH THE THS METHOD

摘要：

This paper dedicates to the experimental determination of thermal conductivities of silica aerogel, xonotlite-aerogel and ceramic fibre-aerogel composite nano-porous insulation materials with the transient hotstrip (THS) method in different temperatures and pressures. The samples of silica aerogel, xonotlite-aerogel and ceramic fibre-aerogel composite insulation materials are firstly prepared. Two appropriative surroundings i.e. an elevated temperature surrounding from ambient temperature to 1450 K and a vacuum surrounding from atmosphere pressure to 10-3 Pa are designed for the THS method. Thermal conductivities of the prepared samples with different densities from ambient temperature to 723 K and 2 Pa to atmospheric pressure are then measured. The results show that both the thermal conductivity of silica aerogel and the two composite nano-porous insulation materials decreases significantly with the drop of pressure, and reaches to a constant at about 104 Pa. Both the thermal conductivity of silica aerogel and the two composite nano-porous insulation materials increase cubic with the rise of temperature. The density of xonotlite-type calcium silicate is the key factor affecting the effective thermal conductivity of xonotlite-aerogel composite insulation material, and the density of aerogel has little influence. The thermal conductivity of silica aerogel has a minimum value when the density is about 145 kg/m3. The effective thermal conductivity of xonotlite-type calcium silicate and ceramic fibre can be lowered greatly by composite with silica aerogel. The thermal conductivity measurement uncertainty is estimated approximately 3 percent at ambient temperature.

关键词： thermal conductivity transient hot-strip method aerogel nano-porous insulation material

作者: Gaosheng Wei Yusong Liu Xinxin Zhang Fan Yu Xiaoze Du

作者单位: School of Energy and Power Engineering,North China Electric Power University,Beijing, China, 102206 Energy Department of Beijing Sustainable Development Centre Beijing, China, 10083 Thermal Engineering Department,University of Science and Technology Beijing Beijing, China, 100083 Thermal Engineering Department, University of Science and Technology Beijing Beijing, China, 100083

会议类型: 国际会议

会议名称: The Ninth Asian Thermophysical Properties Conference(第九届亚洲热物理性能会议 ATPC 2010)

会议地点: 北京

会议语种:英文

页码: 733-738

在线出版日期: 2010-10-19（万方平台首次上网日期，不代表论文的发表时间）