Analyzing Magnetic Refrigeration Efficiency: A Rotary AMR — Reverse Brayton Case Study

  • J. L. Hall
  • J. A. Barclay
Part of the Advances in Cryogenic Engineering book series (ACRE, volume 43)


Recent advances in magnetic refrigerants, regenerative magnetic cycle theory and conduction-cooled superconducting magnet systems have improved the outlook for developing practical, cost-effective magnetic refrigerators. This has prompted an effort to provide an updated estimate of achievable magnetic refrigerator thermodynamic performance as compared to conventional gas-cycle devices. Calculations were performed as part of a case study involving one candidate refrigerator from each technology: rotary active magnetic regeneration and reverse-Brayton gas compression. The study shows that the two systems are very analogous, allowing for a fair comparison. For refrigeration at 100 K and heat rejection at 300 K, both are capable of producing second law efficiencies of over 60% given a similar set of optimistic component performance assumptions. Excellent heat transfer at low-pressure drop was found critical to the success of both systems. The rotary magnetic refrigerator was found to have a clear advantage in work minimization because it relies on efficient electric drives and inherent magnetic force balancing to minimize the net cycle work, rather than coupling isothermal compressors to mechanical expanders to recover work. Several key problems are discussed that must be solved to realize the potential high thermodynamic efficiencies in a cost-effective manner.


Heat Exchanger Entropy Production Entropy Generation Magnetocaloric Effect Magnetic Refrigeration 
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Copyright information

© Springer Science+Business Media New York 1998

Authors and Affiliations

  • J. L. Hall
    • 1
  • J. A. Barclay
    • 1
  1. 1.Cryofuel SystemsUniversity of VictoriaVictoriaCanada

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