1 ATM Subcooled Liquid Nitrogen Cryogenic System for Oxide Superconducting Power Transformer

  • S. Yoshida
  • Y. Yagi
  • T. Umeno
  • T. Ishida
  • Y. Kamioka
  • H. Ogino
  • M. Iwakuma
  • K. Funaki
  • Y. Yasukawa
  • M. Konno
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 43)

Abstract

A subcooled liquid nitrogen cryogenic system was developed for an oxide superconducting power transformer. The performance of the transformer was improved in capacity and in reliability. The transformer is cooled by 1 atm subcooled liquid nitrogen supplied by a pump. The cryogenic system has the refrigeration power of 100 W at 70 K and the capacity of the transformer was improved from 500 kVA at 77 K to 800 kVA at 66 K. Because of the steep temperature gradient at the vicinity of the liquid surface, there is a saturated liquid nitrogen at the liquid surface and an ordinary open-dewar can be used as a cryostat for the transformer. Below the steep temperature gradient region, uniformly subcooled bulk liquid is found and there are no bubbles in the cryostat during operations. This feature makes a reliability of the superconducting power transformer increased.

Keywords

Liquid Nitrogen Heat Exchanger Liquid Surface Heat Load Glass Fiber Reinforce Plastic 
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.

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References

  1. 1.
    K. Funaki et al., Design and Construction of a 500 kVA-Class Oxide Superconducting Power Transformer Cooled by Liquid Nitrogen, in: “Proc. of the 16th ICEC / ICMC,” Elsevier Science, Oxford (1997), p.1009Google Scholar
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    Y. Kamioka et al., A Double Acting Bellows Type liquid helium pump, “Proc. of the 10th ICEC,” Butterworth & Co, Guldford (1984), p.578Google Scholar
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    J.A. Clark, A Review of Pressurization, Stratification, and Interfacial Phenomena, in: “Advances in Cryogenic Engineering,” Vol.10 Sec. M-U, Plenum Press, New York (1965), p.259Google Scholar
  4. 4.
    K. Funaki et al., Preliminary Tests of A 500 kVA-Class Oxide Superconducting Transformer cooled by Subcooled Nitrogen, in: “to be published in Proc. of ASC ‘96 Pittsburgh (1996)”Google Scholar

Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • S. Yoshida
    • 1
  • Y. Yagi
    • 1
  • T. Umeno
    • 1
  • T. Ishida
    • 1
  • Y. Kamioka
    • 1
  • H. Ogino
    • 1
  • M. Iwakuma
    • 2
  • K. Funaki
    • 2
  • Y. Yasukawa
    • 3
  • M. Konno
    • 3
  1. 1.Taiyo Toyo Sanso Co., Ltd.Kawasaki 210Japan
  2. 2.Kyushu UniversityFukuoka 812Japan
  3. 3.Fuji Electric Co., Ltd.Kawasaki 210Japan

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