Minimization of Refrigeration Power for Large Cryogenic Systems

  • M. A. Hilal
  • Y. M. Eyssa
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 35 A)

Abstract

Some cryogenic systems, such as superconducting magnetic energy storage and superconducting generators, require load-bearing supports to transfer forces to a room temperature (warm) structure. It is necessary to minimize the refrigeration power required to overcome heat leaks through the supports in order to improve system efficiency.

Keywords

Entropy Helium Refrigeration 

Notation

A

= strut cross-sectional area

A0

= strut cross-sectional area at room temperature

C

= efficiency constant

Di

= mathematical expression to be used with equation (18) of reference [1].

F

= force

L

= strut length

T

= temperature

TC

= cold-end temperature

TH

= hot-end temperature

QC

= heat conducted to cold end

CP

= helium specific heat

k

= thermal conductivity

m

= total helium mass flow rate

mc

= helium mass flow rate to the support

s

= length variable

x

= liquefied fraction

σn

= normalized stress to room temperature value

σ0

= allowable stress at room temperature

λ

= heat of vaporization

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1.
    M. Hilal and R. W. Boom, in Advances in Cryogenic Engineering, Vol. 22, Plenum Press, New York (1977), p. 224.CrossRefGoogle Scholar
  2. 2.
    A. Bejan and J. L. Smith Jr., Cryogenics 14(3):158 (1974).CrossRefGoogle Scholar
  3. 3.
    A. Bejan and J. L. Smith Jr., in Advances in Cryogenic Engineering, Vol. 21, Plenum Press, New York (1976), p. 247.Google Scholar
  4. 4.
    A. Bejan, Cryogenics 15(5):290 (1975).CrossRefGoogle Scholar
  5. 5.
    M. Hilal, Cryogenics 19(7):415 (1979).CrossRefGoogle Scholar
  6. 6.
    J. Brooks and R. Donnelly, “The Calculated Properties of Helium II,” Tech. Report, The Institute of Theoretical Science, University of Oregon, Eugene, Oregon (1973).Google Scholar
  7. 7.
    M. D. Campbell, “Thermophysical Properties of Plastic Materials and Composites to Liquid Hydrogen Temp. (-423°F),” ML-TDR-64–33, Part III, Air Force Material Laboratory, Wright-Patterson Air Force Base, Ohio (August 1965).Google Scholar

Copyright information

© Springer Science+Business Media New York 1980

Authors and Affiliations

  • M. A. Hilal
    • 1
  • Y. M. Eyssa
    • 2
  1. 1.Michigan Technological UniversityHoughtonUSA
  2. 2.University of Wisconsin—MadisonMadisonUSA

Personalised recommendations