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Research on a magnetic refrigeration cycle for hydrogen liquefaction.

Author(s) : UTAKI T., KAMIYA K., NAKAGAWA T., et al.

Summary

For the upcoming hydrogen society, there are several key technological issues such as hydrogen generation, liquefaction, storage, and transportation. Magnetic refrigeration systems based on the magnetocaloric effect involve intrinsically higher energy efficiency than conventional refrigeration systems at cryogenic temperatures. Thus, they are potentially attractive candidates as a means of hydrogen liquefaction. However, there is little reported data on the refrigeration performance of magnetic refrigeration used as a hydrogen liquefier. To provide the needed data, the authors have evaluated the system parameters required for the design optimization of magnetic refrigerators and estimated their coefficient of performance using a numerical simulation model. The magnetic refrigerator model we have constructed is based on a multistage active magnetic regenerative cycle. In our current model, an ideal magnetic material with constant magnetocaloric effect is employed as the magnetic working substance. The maximum applied field is 5 T, and the liquid hydrogen production rate is 0.01 t/day. Starting from liquid nitrogen temperature (77 K), it is assumed that four separate stages of refrigeration are needed to cool the hydrogen. The results of the simulation show that the use of a magnetic refrigerator for hydrogen liquefaction is possibly more efficient than the use of conventional liquefaction methods. There are several candidate arrangements of magnetic refrigeration liquefaction cycles starting from either room temperature (300 K), or from the temperature of liquid natural gas (120 K). The authors show trial results on efficiency and cooling power for several.

Details

  • Original title: Research on a magnetic refrigeration cycle for hydrogen liquefaction.
  • Record ID : 2008-2399
  • Languages: English
  • Publication date: 2006/06/14
  • Source: Source: Proc. 14th int. Cryocooler Conf., Annapolis, MD
    645-653; fig.; tabl.; 5 ref.

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