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http://dx.doi.org/10.9714/psac.2006.8.1.059

Closed-Loop Cooling System for High Field Mangets  

Choi, Y.S. (한국기초과학지원연구원)
Kim, D.L. (한국기초과학지원연구원)
Lee, B.S. (한국기초과학지원연구원)
Yang, H.S. (한국기초과학지원연구원)
Painter, T.A. (미국 국립고자장 연구소 (NHMFL))
Miller, J.R. (미국 국립고자장 연구소 (NHMFL))
Publication Information
Progress in Superconductivity and Cryogenics / v.8, no.1, 2006 , pp. 59-64 More about this Journal
Abstract
A closed-loop cryogenic cooling system for high field magnets is presented. This design is motivated by our recent development of cooling system for 21 tesla Fourier Transform ion Cyclotron Resonance (FT-ICR) superconducting magnets without any replenishment of cryogen. The low temperature superconducting magnets are immersed in a subcooled 1.8 K bath, which is connected hydraulically to the 4.2 K reservoir through a narrow channel. Saturated liquid helium is cooled by Joule-Thomson heat exchanger and flows through the JT valve, isenthalpically dropping its pressure to approximately 1 6 kPa, corresponding saturation temperature of 1.8 K. Helium gas exhausted from pump is now recondensed by two-stage cryocooler located after vapor purify system. The amount of cryogenic Heat loads and required mass flow rate through closed-loop are estimated by a relevant heat transfer analysis, from which dimensions of JT heat exchanger and He II heat exchanger are determined. The detailed design of cryocooler heat exchanger for helium recondensing is performed. The effect of cryogenic loads, especially superfluid heat leak through the gap of weight load relief valve, on the dimensions of cryogenic system is also investigated.
Keywords
heat transfer; heat exchangers; cryostats; superconducting magnets;
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  • Reference
1 Painter T. A. et al., "Conceptual design of superconducting magnet system for 21 T fourier transform ion cyclone resonance mass spectrometer", In: International Conference on Magnet Technology, September 2005, Paper#TUA30R3
2 Ueno Y. et al., "Numerical study on characteristics of a pre-cooling He II heat exchanger", Advances in Cryogenic Engineering, Vol.49, 1039-1046, 2004
3 Product Catalogue of Cryomech. Model PT415, New York, 2005, Available from: http://www.cryomech.com
4 Barron R.F., "Cryogenic Heat Transfer", Philadelphia, Taylor & Francis, 1999
5 Van Sciver S.W., "Heat transfer through an extended surface containing He II", Journal of Heat Transfer, Vol.121, 142-147, 1999   DOI   ScienceOn
6 Ng K.C. et al., "Experimental and numerical study on a miniature Joule-Thomson cooler for steady-state characteristics, Int. J. Heat and Mass Transfer, Vol. 45, 609-618, 2002   DOI   ScienceOn
7 Gerald C.F, Wheatly P.O., "Applied Numerical Analysis", New York, Addition-Wesley, 1996
8 Mardion G.B. et al.. "Practical data on steady state heat transport in superfluid helium at atmospheric pressure", Cryogenics, Vol.19, 45-47, 1979   DOI   ScienceOn
9 National Research Council, "Opportunities in high magnetic field science", National Academy of Sciences, Washington D. C., 2004, Available from: http://www.nap.edu
10 Kiyoshi T. et al., "Operation of a 920-NHz high-resolution NMR magnet at TMI". IEEE Trans Appl Supercond, Vol. 13, 1391-1395, 2003   DOI   ScienceOn
11 Matsumoto F. et al., "Testing of superfluid-coo led 920 MHz NMR cryostat", Advances 10 Cryogenic Engineering, Vol.47, 383-390, 2002
12 Dixon I. R. et al.. "Performance of the ultra wide bore 900 MHz NMR magnet at the National High Magnetic Field Laboratory", IEEE Trans Appl Supercond, Vol. 15, 1334-1337, 2005   DOI   ScienceOn
13 Choi Y.S. et al., "Conceptual design of cryogenic cooling system for 21 T ICR Magnetsmeter". In: International Conference on Magnet Technology, September 2005, Paper#WEA03PO10
14 Van Sciver S.W., "Helium Cryogenics", New York, Plenum Press, 1986