Accession Number : ADA184994
Title : Magnetocaloric Refrigeration.
Descriptive Note : Research and development rept.,
Corporate Author : DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD
Personal Author(s) : Green, Geoffrey ; Patton, George ; Stevens, John ; Humphrey, James
PDF Url : ADA184994
Report Date : Mar 1987
Pagination or Media Count : 46
Abstract : The magnetocaloric refrigerator uses the adiabatic temperature response of ferromagnetic materials (rare-earth metals) in a high magnetic field. A mathematical model of a reciprocating magnetic refrigerator having an active element of a rare-earth metal predicted that a 60-K temperature span could be achieved. Based on the model's results, an experimental refrigerator was fabricated and the thermal characteristics of an active regenerator in a reciprocating apparatus were measured. The active material was gadolinium, which has a Curie temperature of 293 K and was formed into an embossed ribbon geometry. Significant regeneration in the magnetic material was observed, and a 50-K temperature span was achieved. A cold end temperature of 246 K was measured. The results indicated that the active regeneration concept can successfully produce magnetocaloric refrigeration at temperatures near the Curie temperature of the material, and the measured temperature span verified the mathematical model developed to describe the process. Further, if the active magnetic element were a combination of several rare-earth metals having significant magnetocaloric effects at decreasing temperatures, the possibility exists for producing a single-stage magnetic refrigerator that could operate over a very large temperature span.
Descriptors : *REFRIGERATION SYSTEMS, GADOLINIUM, MAGNETIC DRIVES, MAGNETIC MATERIALS, REGENERATIVE COOLING, CURIE TEMPERATURE
Subject Categories : Air Condition, Heating, Lighting & Ventilating
Metallurgy and Metallography
Distribution Statement : APPROVED FOR PUBLIC RELEASE