Thermodynamic Performance Characteristics of a Regenerative Brayton Refrigeration Cycle Using Gd<sub>0.45</sub>Tb<sub>0.55</sub> and Gd as the Working Substance

Abstract

Based on experimental characteristics of the iso-field heat capacity of the working substances Gd0.45Tb0.55 and Gd, the magnetic entropy change with temperature is calculated. The regenerative Brayton refrigeration cycles employing these materials as the working substances are established. By means of thermodynamic analysis and numerical calculation, the effects of the non-perfect regeneration on the performance characteristics of the refrigeration cycles are revealed. Furthermore, the cyclic performances employing Gd0.45Tb0.55 and Gd as the working substances are evaluated and compared. The results obtained may provide some useful information for the optimal design of the room temperature magnetic refrigerators.