采用瞬态热带法在不同压力和不同温度下对气凝胶、硬硅钙石-气凝胶及陶瓷纤维-气凝胶复合绝热材料的导热系数进行了测量.结果表明,随着测试压力的降低,三种材料的导热系数都显著降低,在大约104 Pa时基本趋于常数;随着温度的升高,三种绝热材料的导热系数几乎与温度的立方成正比;当气凝胶的密度为145 kg/m3时,其导热系数具有最小值,而气凝胶密度对复合型绝热材料导热系数的影响不大.误差分析表明室温环境下的测量误差在3%以内.
参考文献
| [1] | J. E. Fesmire;J. P. Sass .Aerogel insulation applications for liquid hydrogen launch vehicle tanks[J].Cryogenics,2008(5/6):223-231. |
| [2] | M. Reim;W. Koerner;J. Manara;S. Korder;M. Arduini-Schuster;H.-P. Ebert;J. Fricke .Silica aerogel granulate material for thermal insulation and daylighting[J].Solar Energy,2005(2):131-139. |
| [3] | Gaosheng Wei;Xinxin Zhang;Fan Yu .Thermal Conductivity of Xonotlite Insulation Material[J].International Journal of Thermophysics,2007(5):1718-1729. |
| [4] | Zheng Q.;Wang W. .Calcium silicate based high efficiency thermal insulation[J].British Ceramic Transactions,2000(4):187-190. |
| [5] | Hailong Yang,Wen Ni,Deping Chen,Guoqiang Xu,Tao Liang,Li Xu.Mechanism of low thermal conductivity of xonotlite-silica aerogel nanoporous super insulation material[J].北京科技大学学报（英文版）,2008(05):649-653. |
| [6] | Gaosheng Wei,Xinxin Zhang,Fan Yu.Thermal conductivity measurements on xonotlite-type calcium silicate by the transient hot-strip method[J].北京科技大学学报（英文版）,2008(06):791-795. |
| [7] | Zeng J.S.Q.;Greif R. .Effective optical constants n and K and extinction coefficient of silica aerogel[J].Journal of Materials Research,1996(3):687-693. |
| [8] | Gaosheng Wei;Xiaoze Du;Xinxin Zhang;Fan Yu .Theoretical Study on Transient Hot-Strip Method by Numerical Analysis[J].Journal of heat transfer: Transactions of the ASME,2010(9):091301-1-091301-7. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%