The Active Magnetic Regenerator (AMR) is a promising technology for cryogen liquefaction, however commercially relevant performance has yet to be reported. A central issue is the rapid change of magnetization in the superconducting windings, which is exacerbated as prototypes scale in capacity. This underlying problem has been avoided by reducing magnetic field strengths and device sizes which, consequentially, has impeded the development of AMR liquefiers. To solve this problem, we present a force minimization approach using passive magnetic material to balance the magnetization of a dual-regenerator AMR. A magnetostatic model is developed and validated with experimental measurements. A genetic algorithm identifies force-minimizing passive structures with virtually ideal balancing characteristics. Implementation details are investigated which affirm the potential of the proposed methodology for AMR liquefiers.
Revised: November 28, 2017 |
Published: April 1, 2018
Citation
Teyber R.P., K.D. Meinhardt, E.C. Thomsen, E. Polikarpov, J. Cui, A. Rowe, and J.D. Holladay, et al. 2018.Passive Force Balancing of an Active Magnetic Regenerative Liquefier.Journal of Magnetism and Magnetic Materials 451.PNNL-SA-128790.doi:10.1016/j.jmmm.2017.11.002