Advertisement

Sizing an Emergency Venting System for a Cryogenic Dewar

  • C. K. Liu
  • L. G. Naes
  • A. F. ManikowskiJr.
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 31)

Abstract

If the vacuum vessel that insulates a cryogenic dewar for a spaceborne experiment prior to launch is damaged, air will leak into the vacuum insulation space. As the sudden heat load causes the pressure to rise in the dewar, a safety disk in the emergency vent line will burst at the design pressure differential to allow vaporized cryogenic fluid to escape. The emergency vent line should be sized such that sufficient gaseous cryogen will be vented to keep the pressure inside the dewar below the design limit. On the other hand, the line should not be so large as to impose an unnecessary heat load on the dewar filled with cryogenic fluid. A vent line computer program was generated to compute the maximum flow rate allowed for a proposed vent line system. Parametric studies have been carried out for different burst disk pressure differentials, liquid cryogen ullage, and vent line sizes. These programs are useful for sizing an emergency venting system for a cryogenic dewar.

Keywords

Mach Number Mass Flow Rate Vacuum Vessel Peak Flow Rate Expulsion Rate 
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.
    C. K. Liu, L. G. Naes, and A. F. Manikowski Jr., Catastrophic Heat Load on a Solid Hydrogen Dewar, AIAA-85-0960, presented at AIAA 20th Thermophysics Conference, Williamsburg, VA (19–21 June 1985 ).Google Scholar
  2. 2.
    Personal Communications with Suresh Patel, Manager, Special and Nuclear Products, Ametek, Straza Division, El Cajon, CA.Google Scholar
  3. 3.
    W. M. Rohsenow and J. P. , eds., “Handbook of Heat Transfer” McGraw-Hill, New York (1973).Google Scholar
  4. 4.
    W. M. Kays and M. E. Crawford, “Convective Heat and Mass Transfer,” Second Edition, McGraw-Hill, New York (1980).Google Scholar
  5. 5.
    W. C. Reynolds, “Thermodynamic Properties in SI,” Department of Mechanical Engineering, Stanford University (January 1979).Google Scholar

Copyright information

© Plenum Press, New York 1986

Authors and Affiliations

  • C. K. Liu
    • 1
  • L. G. Naes
    • 1
  • A. F. ManikowskiJr.
    • 1
  1. 1.Lockheed Research & Development DivisionPalo AltoUSA

Personalised recommendations