Design and performance of a room-temperature hybrid magnetic refrigerator combined with Stirling gas refrigeration effect

The experimental prototype described in this work is a hybrid refrigerator that combines the active magnetic refrigeration effect with the Stirling gas regenerative refrigeration effect. In this prototype, gadolinium sheets are packed in the regenerator matrix for both Stirling and active magnetic regenerative refrigeration. Experimental tests were carried out to measure the cooling performance of this hybrid prototype. The influence of the phase angle on the cooling performance was investigated, and a reasonable phase angle of 90° was determined to obtain optimal cooling performance. By combining the two refrigeration effects, a minimum cooling temperature without heat load of 3.5 °C was reached, which is lower than that of 6.5 °C for the pure Stirling refrigeration effect without the magnetic cooling effect. The results of this study show that the cooling performance is improved by 24% for the hybrid effects compared with that exploiting only the Stirling gas refrigeration effect.