OPTIMIZATION OF A MAGNETIC REFRIGERATOR AT ROOM TEMPERATURE FOR AIR COOLING SYSTEMS

The purpose of this study was to understand the optimum operation condition of magnetic refrigerator at room temperature for direct air-cooling. The basic components of the target system were a magnetic circuit including two permanent magnets, a test section, an air blower, and an associated instrumentation. The test section consisted of ten test cells which enclosed gadolinium chips as a magnetic working substance in prescribed packing factor. In order to change the applied magnetic field from 0 to 0.9T, the magnetic circuit was installed on an electric slider which generated reciprocating motion. The system performances were widely investigated both experimentally and analytically for the variety of operation conditions such as a volumetric flow rate of air, a packing mass of magnetic working substance, and a heat exchange cycle. The results reveal that the maximum value of the cooling capacity of the present magnetic refrigerator is obtained in a certain operating condition.