Advertisement

Aerogel-Based Cryogenic Superinsulation

  • J. E. Fesmire
  • S. Rouanet
  • J. Ryu
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 44)

Abstract

This paper presents the development of a flexible, easy-to-use superinsulation. The innovative material system employs ultralow density aerogels within a flexible fiber matrix for minimum heat transfer and maximum applicability and durability. The core of the system is aerogels formed at the fiber-fiber contacts of the matrix, forcing solid conduction to occur through the aerogels. This composite configuration improves both the ease of handling aerogels and the overall thermal resistance. The close-packed structure of the aerogels also eliminates the open spaces in the fiber matrix and thereby reduces gas conduction. Excellent thermal resistance was achieved for both evacuated and nonevacuated insulation systems while maintaining structural flexibility. The aerogels were also produced in an opacified fiber matrix. Testing of these composites indicated a significant inhibition of radiation in the infrared range. Thermal performance was measured by transient heat flux and liquid nitrogen boiloff methods. The apparent thermal conductivity of the silica-aerogel/fiber composite was lower than 1 milliwatt per meter-kelvin (mW/m-K) at a high vacuum level [below 1×10−5 millibars (mbar)] and below 10 mW/m-K in ambient pressure nitrogen (boundary temperatures were approximately 77 K and 280 K for all tests). Performance was found to be insensitive to residual gas pressure up to a vacuum level of about 1×10−1 mbar. Aerogel-based superinsulation systems have been produced and tested in blanket, sheet, and clamshell forms for use on a variety of cryogenic equipment.

Keywords

Silica Aerogel Fiber Matrix Aerogel Composite Small Business Innovation Research Solid Conduction 
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.
    L. W. Hrubesh and R. W. Pekala, Thermal properties of organic and inorganic aerogels, J. Mater. Res., Vol. 9, No. 3, March (1994).Google Scholar
  2. 2.
    P.H. Tewari, K.D. Lofftus, and A.J. Hunt, Structure and chemistry of sol-gel derived transparent silica aerogel, Proceedings of 2nd International Conference on Ultrastructure Processing of Ceramics, Glasses, and Composites, Palm Coast FL (1985).Google Scholar
  3. 3.
    B. Ranjarajan and C. T. Lira, Production of Aerogels, Journal of Supercritical Fluids, Vol. 4, (1991) pp. 1–6.CrossRefGoogle Scholar
  4. 4.
    W. J. Schmidt, R.A. Greiger-Block, and T.W. Chapman, The Preparation of Acid Catalzyed Silica Aerogel, University of Wisconsin, Madison (1981).Google Scholar
  5. 5.
    C.J. Binker and G.W. Scherer. “Sol-Gel Science: The Physics and Chemistry of Sol-Gel Processing,” Academic Press (1990).Google Scholar
  6. 6.
    ASTM D3663–92, American Society for Testing of Materials, Philadelphia (1992).Google Scholar
  7. 7.
    ASTM E595–93, American Society for Testing of Materials, Philadelphia (1993).Google Scholar
  8. 8.
    NHB 8060.IC, National Aeronautics and Space Administration (1991).Google Scholar
  9. 9.
    P. J. Schnieder. “Temperature Response Charts,” John Wiley and Sons, New York (1963).Google Scholar
  10. 10.
    S. Kakac and Y. Yener. “Heat Conduction,” 3`d Ed., Taylor and Francis, Washington, DC (1993), pp. 51–52.Google Scholar
  11. 11.
    R. F. Barron. “Cryogenic Systems,” 2°d Ed., Oxford University Press, New York (1985), pp. 391–399.Google Scholar
  12. 12.
    R. M. Fay and M. A. Albers, Fiber Glass for Insulating Cryogenic Tanker Systems, Thermal Insul. and Bldg. Envs., Vol. 17, July (1993).Google Scholar
  13. 13.
    L. Adams, Thermal conductivity of evacuated perlite, Cryogenic Technology, Vol. 1, No. 6 (1965).Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • J. E. Fesmire
    • 1
  • S. Rouanet
    • 2
  • J. Ryu
    • 2
  1. 1.Engineering Development DirectorateNASA Kennedy Space CenterKSCUSA
  2. 2.Aspen Systems, IncorporatedMarlboroughUSA

Personalised recommendations