Magnetic Refrigeration – an Energy Efficient Technology for the Future

Magnetic refrigeration is an emerging technology that has the potential to significantly reduce the energy consumption in the refrigeration sector. The technology relies on the heating and cooling of magnetic materials upon the application and removal of a magnetic field, respectively. This magnetocaloric effect is inherent to all magnetic materials, but manifests itself stronger in some materials. The thermodynamically reversible nature of the magnetocaloric effect holds out the promise of a more energy efficient method of refrigeration compared to conventional compressor technology. Coupling this with an absence of ozone depleting and greenhouse contributing gasses gives magnetic refrigeration the potential to become an environmentally sustainable technology. The magnetic refrigeration group at Risø DTU aims to demonstrate the technology in a prototype magnetic refrigeration device. Our work spans a wide range of scientific and technological areas. At the pure science end there is the development and understanding of new magnetocaloric materials, while the design and implementation of a prototype device along with the processing of materials is at the technological engineering end. Tying the work together are advanced numerical computer models of the individual parts of the prototype. A simple yet versatile test machine located at Risø DTU is used to test and characterise new materials and to test the design, configuration and operating conditions relevant for a prototype device, while ensuring understanding through consistency with the numerical models.