Magnetic refrigerator development. Final report

Technical Report · Wed Apr 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/6532887· OSTI ID:6532887

Barclay, J. A.; Steyert, W. A.

The reseach program to develop magnetic refrigeration in the 4 to 10K temperature region is described. The original purpose of the program was to provide more efficient refrigeration for superconducting technological applications in power generation and transmission. However, the work reported forms part of the basis for a whole new refrigeration technology with a myriad of applications extending beyond the original objective. To initiate development of the low-temperature refrigerator technology, a gadolinium-metal, magnetic-wheel prototype was designed, built, and tested at room temperature with the objective of understanding the device in an experimentally convenient temperature region. When operating through a 6-T magnetic-field difference, the wheel was designed to provide 1 kW of continuous refrigeration across a 40K span near room temperature and to operate at 70% of Carnot efficiency. The prototype operated through a 1.2-T field difference and provided 1/2 kW of continuous refrigeration over a 7K span at 26% of Carnot efficiency. One problem that was found with this first device was the difficulty of producing simultaneously a high, homogeneous field across the top of the wheel with almost zero field across the bottom of the wheel. Problems with fluid-flow control of both transient and entrained fluid were also encountered. Nevertheless, the performance results at 1.2-T field difference are those predicted by the theory used to determine the design objectives at 6-T field difference. The results of several experiments show that the principle of operation is understood and offers exciting prospects. Experiments with water as the heat exchange fluid and gadolinium as the magnetic material provided up to 1/2-kJ/cycle of refrigeration. The key problem uncovered is that of compensating large magnetic forces while keeping parasitic heat leaks to a minimum.

• Research Organization: Los Alamos Scientific Lab., NM (USA)
• OSTI ID: 6532887
• Report Number(s): EPRI-EL-1757
• Country of Publication: United States
• Language: English

Related Subjects

200303 -- Power Transmission & Distribution-- Superconducting & Cryogenic Systems-- (-1989)
24 POWER TRANSMISSION AND DISTRIBUTION
420201* -- Engineering-- Cryogenic Equipment & Devices
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CABLES
CONDUCTOR DEVICES
CRYOGENICS
DATA
DESIGN
EFFICIENCY
ELECTRIC CABLES
ELECTRICAL EQUIPMENT
ELEMENTS
EQUIPMENT
EXPERIMENTAL DATA
GADOLINIUM
HEAT EXCHANGERS
INFORMATION
MAGNETIC FIELDS
MAGNETIC REFRIGERATORS
METALS
NUMERICAL DATA
PERFORMANCE
PHYSICAL PROPERTIES
POWER TRANSMISSION
RARE EARTHS
REFRIGERATORS
SUPERCONDUCTING CABLES
THERMODYNAMIC PROPERTIES
ULTRALOW TEMPERATURE