Solid-state magnetic refrigerator based on the demagnetizing effect

With population growth, changes in lifestyle and global warming, the demand for ecological and low-energy consumption technologies is rising sharply. Magnetic refrigeration is a promising alternative to conventional refrigeration. However, several factors still impair its performance, thereby delaying commercialization. The use of thermal management elements (such as thermal switches) instead of thermal fluids for heat transfer can avoid some of the main issues arising from conduction/convection, fluid oscillation and mechanical friction. Furthermore, the rotating magnetocaloric effect can effectively solve the problem of the demagnetizing field commonly associated with this technology. Therefore, here we propose and numerically simulate a novel solid-state magnetic refrigerator based on the rotating magnetocaloric effect, generated by the alternated rotation of magnetocaloric material plates under a constant magnetic field. The performance of the proposed device improves with the decrease in the inverse aspect ratio of the magnetocaloric material plates, reaching a maximum no-load temperature span of 2.02 K. The implementation of asymmetric cycles can lead to enhancements of up to 30% in the temperature span, which compensates the use of low-intensity magnetic fields in future applications. This innovative and compact model enables the development of a novel class of magnetic refrigerators based on the rotating magnetocaloric effect.