Advertisement

Load-Bearing Evacuated Fibrous Superinsulations — Improvements with Peg-Support and Metal-Coated Fibers

  • J. Fricke
  • D. Büttner
  • R. Caps
  • G. Döll
  • E. Hümmer
  • A. Kreh
  • H. Reiss

Abstract

Optimization of load-bearing evacuated thermal superinsulations requires a detailed investigation of two thermal loss channels: The solid conduction via contacting fibers, and the radiative heat transfer. In this paper we report two important findings which allow to further improve thermal superinsulations: (i) with metal-coated fibers we obtained extinction coefficients of several hundred m2/kg; this corresponds to a drastic reduction of radiative losses compared to the case of non-coated fibers; (ii) with peg-supported insulation systems the solid conductivity was reduced to about 0.5·10-3 W/(m·K) at 1.15 bar external pressure; this could lead to an improvement by more than a factor of three compared to not-segmented fibrous insulations. The measurements were performed with evacuable and load-controlled guarded hot plate devices and with a FTIR spectrometer.

Keywords

Fume Silica Radiative Heat Transfer Radiative Temperature Loss Coefficient Total Thermal Conductivity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. [1]
    D. Büttner, J. Fricke and H. Reiss, Analysis of radiative and solid conduction components of the total thermal conductivity of an evacuated glass fiber insulation, measurements with a 700 x 700 mm2 variable load guarded hot plate device, AIAA 20th Thermophysics Conf., June 1985, Williamsburg,Va., paper No. 85 - 1019Google Scholar
  2. [2]
    P. Scheuerpflug, R. Caps, D. Büttner and J. Fricke, Internat. J. Heat Mass Transfer 28, 2299 (1985).CrossRefGoogle Scholar
  3. [3]
    Report Union Carbide Corporation - Linde Division Tonawanda, N.Y., Contract No. EM-78-C-01-5160 (1979).Google Scholar
  4. [4]
    K. Y. Wang, C. L. Tien, J. Quant. Spectrosc. Radiat. Transfer 30, 213 (1983).CrossRefGoogle Scholar

Copyright information

© Purdue Research Foundation 1989

Authors and Affiliations

  • J. Fricke
    • 1
  • D. Büttner
    • 1
  • R. Caps
    • 1
  • G. Döll
    • 1
  • E. Hümmer
    • 1
  • A. Kreh
    • 1
  • H. Reiss
    • 2
  1. 1.Physikalisches Institut der Universität WürzburgWürzburgW.-Germany
  2. 2.Brown, Boveri & CieHeidelbergW.-Germany

Personalised recommendations