Study on layered beds arrangement for active magnetic refrigerator.

This study investigates the optimum structure of layered beds of manganese (Mn)-based alloys for an active magnetic refrigerator using one-dimensional heat transfer numerical analysis. The parameter used in the analysis is the Curie temperature interval. The active magnetic regenerator duct length is fixed at 150 mm. The analysis shows that the cooling power for a 2 °C interval and 13 types of material (length: 11 or 12 mm per material) is higher than that for a 6 °C interval and 5 types of material (length: 30 mm per material). The intersection point of the magnetic entropy change distributions of adjacent materials is at about 40% and 90% of the peak magnetic entropy change value for a 6 °C and 2 °C interval, respectively. Based on the results, high cooling power can be obtained when the intersection point is more than about 90% of the peak magnetic entropy change value.