Development of a neon cryogenic turbo-expander with magnetic bearings

H. Hirai, M. Hirokawa, S. Yoshida, Y. Kamioka, A. Takaike, H. Hayashi, H. Okamoto, Y. Shiohara

Research output: Chapter in Book/Report/Conference proceedingConference contribution

10 Citations (Scopus)


A cryogenic turbo-expander with active magnetic bearings was made and tested in a reverse-Brayton cycle refrigerator using neon as working fluid. Turbine isentropic efficiency is a very important factor for the refrigerator since it affects the performance of the refrigerator significantly. Properties of neon are suitable for the working fluid in a refrigerator to cool HTS (High Temperature Superconducting) applications. The neon refrigerator needs a very small and high speed turbo-expander. But there are few studies of isentropic efficiencies of cryogenic turbo-expander using neon gas. Thus the experiment to get the design information was carried out. A prototype of neon refrigerator was made for HTS applications in 2007. Its cooling power was 2 kW at temperature of 70 K and operated in process pressure between 2 MPa and 1 MPa. To improve the performance of the neon refrigerator, the process pressure was changed to 1 MPa∼0.5 MPa. Under this process pressure, isentropic efficiencies for two types of turbine impellers were obtained. The test results were included in to the turbine design program so that we could predict the isentropic efficiencies of the turbo-expander more accurately. Details of the turbo-expander design and test results are described in this report.

Original languageEnglish
Title of host publicationAdvances in Cryogenic Engineering - Transactions of the Cryogenic Engineering Conference-CEC
Number of pages8
Publication statusPublished - 2010
Externally publishedYes
Event2009 Joint Cryogenic Engineering and International Cryogenic Materials Conferences - Tucson, AZ, United States
Duration: Jun 28 2009Jul 2 2009

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


Conference2009 Joint Cryogenic Engineering and International Cryogenic Materials Conferences
Country/TerritoryUnited States
CityTucson, AZ

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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