Advances in Cryogenic Engineering pp 1675-1682 | Cite as
Test Results on a 50K Magnetic Refrigerator
Abstract
The cost and scaling properties of superconducting magnets used in magnetic cryocoolers suggest that magnetic refrigeration is best employed in the medium power range (cooling entropy flows of about 1 W/K) rather than in the small sizes demonstrated to date. A medium scale magnetic refrigerator has been built and tested as a result of a cooperative project between the Astronautics Corporation of America and Oak Ridge National Laboratory. The device uses two active magnetic regenerative beds of GdNi2 reciprocated at up to 0.5 Hz into the bore of a fixed superconducting solenoid. The beds are linked to fixed LN2 hot heat exchangers and a fixed electrically heated cold heat exchanger by flexible metal hoses. The device developed a 35 K temperature span at no load, and a 30 watt cooling power at a reduced temperature span. Testing showed that the dominant losses in this type of design occur from the effects of pressure drop and dead volume in the flexible hoses. Mechanisms of minimizing these losses will be discussed.
Keywords
Pressure Drop Dead Volume Magnetocaloric Effect Vacuum Vessel Cooling PowerPreview
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