Comprehensive thermal transmittance investigations carried out on opaque aerogel insulation blanket

详细信息    查看全文

• 作者：Ákos Lakatos
• 刊名：Materials and Structures
• 出版年：2017
• 出版时间：February 2017
• 年：2017
• 卷：50
• 期：1
• 全文大小：1,148 KB
• 刊物类别：Engineering
• 刊物主题：Structural Mechanics
  Theoretical and Applied Mechanics
  Mechanical Engineering
  Operating Procedures and Materials Treatment
  Civil Engineering
  Building Materials
  
• 出版者：Springer Netherlands
• ISSN：1871-6873
• 卷排序：50

文摘

As it is well known, thermal insulating of buildings is one of the most important methods to reduce the energy loss of buildings and to reduce the emission of green house gases. This paper studies the conductive heat transfer in silica aerogel, moreover, through a wall structure covered with this insulator. Aerogels are nanoporous lightweight materials that were discovered more than 70 years ago. Nowadays their applications are truly widespread. In this article measurement results and theoretical backgrounds are presented. At first, thermal conductivity measurement results of individual insulation materials with different thicknesses (0.013, 0.026, 0039, 0.052, 0.065 m) were achieved by a Holometrix type heat flow meter. Afterwards, two different steady-state methods for measuring thermal resistance of wall structures (Calibrated chamber method and Heat Flux measurements by Hukseflux apparatus) were applied. These measurements were accomplished through an inbuilt plaster/brick/plaster wall construction individually and then it was covered with a 0.013 m thick aerogel layer. The other main target of this paper is to estimate the retardation time of wall structures before the equilibrium stage with the presented novel theoretical method. Furthermore, numerical predictions for thermal resistance and thermal properties (diffusion, heat absorption, inertia) are presented and infrared thermographs are used to visualise the insulation ability of the layer structures, as well. The novelties of the article can be found once in the declared method for the measurement of the initial state thermal retardation of walls, furthermore in the presentation of the effective thermal conductivity of the aerogel and the comparison of the measurements of the same value by different methods. Moreover, the measurement results were used as predictions and suggestions for users.KeywordsSilica aerogelThermal insulationHeat transferThermal conductivityRetardation time