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

Porosity Carbide Total Heat Attenuation Refraction 

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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
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    P. Scheuerpflug, R. Caps, D. Büttner and J. Fricke, Internat. J. Heat Mass Transfer 28, 2299 (1985).CrossRefGoogle Scholar
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    Report Union Carbide Corporation - Linde Division Tonawanda, N.Y., Contract No. EM-78-C-01-5160 (1979).Google Scholar
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    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

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