MagCool - Energy efficient and environmentally friendly cooling using magnetic refrigeration
Magnetic refrigeration is an emerging technology using solid, non-volatile magnetic materials as the active components, and water or alcohol as the medium for heat transport. It holds great potential for energy efficient and environmentally friendly cooling at a competitive price. Internationally, the field of magnetic refrigeration is experiencing a marked increase in activity, as the commercial possibilities of the technology are becoming evident. The present project has advanced the technology to a point where a prototype device has been constructed.
The project was led by the Fuel Cells and Solid State Chemistry Department at Risø DTU together with the Department of Mechanical Engineering and Management at DTU. The two industrial partners, involved in the project Danfoss A/S and Sintex A/S, brought key competences in systems design, refrigeration technology and permanent magnet design to the project.
The proposed project focuses on the crucial challenges for the technology: Development of better ceramic materials, development of cheap, high-field permanent magnets, and design and optimisation of the entire system. The goal of the project was the construction of a proof-of-concept prototype of a magnetic refrigerator using magnetocaloric ceramics and permanent magnets. The prototype should demonstrate the commercial perspectives of the technology. The goal was achieved through a number of specific tasks carried out by Ph.D. students and postdocs:
Materials and component development. This includes development and characterisation of ceramic materials with improved and tuneable magnetocaloric effect, and development of a high field permanent magnet with suitable field characteristics. Modelling and simulation which will give input to both magnet development and to optimisation and design of the magnetic refrigerator system. Prototype design and testing. This will include basic design, processing and test of components, and finally test and characterisation of the prototype.
We have occupied 8 positions out of the 8 planned (4 Ph.D.s and 4 postdocs). We have during the project made 8 compositions of ceramic materials each varying the transition temperature by 4 ºC which gave a temperature span of about 28 ºC. Simultaneously, we have tried to explore other new materials often in collaboration with companies who produce these materials. A novel permanent magnet assembly was designed for the prototype. It has been built and delivered, and an excellent correlation is observed between the model predication and the actual design. A new advanced and computationally efficient numerical model describing the Active Magnetic Regenerator (AMR) was written and tested intensively. We have than assembled the prototype and tested it for the first time with great success. It shows a performance comparable and on some points better than the current state of the art prototype developed by Astronautics (US).
Finally, we have published more than 33 papers in peer reviewed journals (2 of which are review papers) and 20 peer reviewed conferences papers and given 12 invited presentation. Furthermore, we have submitted and successfully defended 4 academic Ph.d. dissertations. Currently our group is considered to be one of the leading groups in this area as cited by some of the leading researchers in this area: “the world‟s most comprehensive magnetic refrigeration research center” K.A. Gschneidner et al., Int. J. Refr. 33 (2010), 645.
Key figures
Category
Participants
Partner | Subsidy | Auto financing |
---|---|---|
Danmarks Tekniske Universitet (DTU) | ||
Danfoss A/S | ||
SINTEX A/S |
Contact
Danmarks Tekniske Universitet. Risø Nationallaboratoriet for Bæredygtig Energi (Risø DTU). Afdelingen for Brændselsceller og Faststofkemi
Frederiksborgvej 399, Bygn. 232
DK-4000 Roskilde
www.risoe.dtu.dk
Pryds, Nini , 46775752, nipr@dtu.dk
Øvr. Partnere: Danmarks Tekniske Universitet. Institut for Mekanisk Teknologi (DTU Mekanik); Danfoss Refrigeration and Air Conditioning Division; Sintex A/S