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Design of magnetic bearings for turbo refrigerant compressors

Published online by Cambridge University Press:  20 June 2014

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Abstract

Magnetic bearings are oil-free bearings that are widely employed in turbo machineries such as turbo refrigerant compressors in order to eliminate lubrication systems, avoid contamination, and increase efficiency. We have developed a 145 refrigerant ton (RT)-class turbo refrigerant compressor using homopolar-type radial hybrid magnetic bearings (HMBs) and thrust magnetic bearings. The thrust magnetic bearing comprises a thrust HMB and a permanent magnet that generate downward forces to overcome high upward thrust forces of 2000 N at 21 000 rpm. A test rig and controller for the compressor with magnetic bearings were fabricated, and rotordynamics such as the unbalance response and axial displacement were investigated. Rotordynamics analyses using the finite element method predicted that the 1st bending mode is located at a high frequency with sufficient margin from the operating speeds. Further, the zero-to-peak displacement caused by the unbalanced response was sufficiently small. The rotor was stably supported with few vibrations across the entire range of the operational speeds. Our results demonstrate that the advantages of oil-free bearings can be easily exploited in turbo machineries such as turbo refrigerant compressors by adopting HMBs.

Type
Research Article
Copyright
© AFM, EDP Sciences 2014

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References

Knospe, C.R., Active magnetic bearings for machining applications, Control Eng. Pract. 15 (2007) 307313 CrossRefGoogle Scholar
G. Schweitzer, Applications and research topics for active magnetic bearings, IUTAM Symposium on Emerging Trends in Rotor Dynamics, Springer, Netherlands, 2011, pp. 263−273
DellaCorte, C., Zaldana, A.R., Radil, K.C., A systems approach to the solid lubrication of foil air bearings for oil-free turbomachinery, J. Tribol. 126 (2004) 200207 CrossRefGoogle Scholar
Asakura, H., Saji, N., Yoshinaga, S., Ishizawa, T., Ikeuchi, M., Yanagi, H., Hirao, Y., Kitagawa, K., Development of a highly reliable helium refrigeration system-R&D of a highly reliable helium refrigeration system (oil-free type), Cryogenics 42 (2002) 203208 CrossRefGoogle Scholar
Rao, J.S., Tiwari, R., Design optimization of double-acting hybrid magnetic thrust bearings with control integration using multi-objective evolutionary algorithms, Mechatronics 19 (2009) 945964 CrossRefGoogle Scholar
Morales, W., Fusaro, R., Kascak, A., Permanent magnetic bearing for spacecraft applications, Tribol. Trans. 46 (2003) 460464 CrossRefGoogle Scholar
Fang, J., Le, Y., Sun, J., Wang, K., Analysis and design of passive magnetic bearing and damping system for high-speed compressor, IEEE Magn. Trans. 47 (2012) 47344739 Google Scholar
Hirai, H., Hirokawa, M., Yoshida, S., Kamioka, Y., Takaike, A., Hayashi, H., Okamoto, H., Shiohara, Y., Development of a neon cryogenic turboexpander with magnetic bearings, AIP Conf. Proc. 1218 (2010) 895902 CrossRefGoogle Scholar
L. Sun, H. Lin, Device to relieve thrust load in a rotor-bearing system using permanent magnets, WIPO Patent No. 2004007984. Geneva, Switzerland
Park, C.H., Choi, S.K., Ahn, J.H., Ham, S.Y., Kim, S., Thrust Hybrid Magnetic Bearing using Axially Magnetized Ring Magnet, J. Magn. 18 (2013) 302307 CrossRefGoogle Scholar
Lee, A.C., Hsiao, F.Z., Ko, D., Analysis and testing of magnetic bearing with permanent magnets for bias, JSME Int. J. Ser. C 37 (1994) 774782 Google Scholar
Lee, A.C., Hsiao, F.Z., Ko, D., Performance limits of permanents-magnet-biased magnetic bearings, JSME Int. J. Ser. C 37 (1994) 783794 Google Scholar
Maslen, E.H., Allaire, P.E., Noh, M.D., Sortore, C.K., Magnetic bearing design for reduced power consumption, J. Tribol. 118 (1996) 839846 CrossRefGoogle Scholar
Fan, Y.H., Lee, A.C., Design of a permanent/electromagnetic magnetic bearing-controlled rotor system, Journal of the Franklin Institute 334 (1997) 337356 CrossRefGoogle Scholar
S.Y. Yoo, C.H. Park, S.K. Choi, M.K. Noh, Identification of flexible rotor modeling for a large capacity flywheel energy storage system, Proceedings of 15th International Congress on Sound and Vibration, Daejeon, Korean, 2008, pp. 1042−1049
C.H. Park, S.K. Choi, Y.S. Son, Y.H. Han, Development of 5 kWh flywheel energy storage system using MATLAB/xPC Target, Proceeding of the WRI World Congress on Computer Science and Information Engineering, Los Angeles, California, 2009, pp. 701–705