A new technology that will revolutionize the refrigeration industry world: magnetic cooling
Currently, the actual cooling and air conditioning systems based on vapor compression technology, a technology that’s been around for over 100 years. Even if a reliable technology and a relatively low price, it has several drawbacks such as a coefficient of performance (COP) of about 2.5 to 3 and use that as cold substances dangerous chemicals to the environment such as hydrofluorocarbons (HFCs), chlorofluorocarbons (CFC) or ammonia (NH3). Magnetic cooling systems using prototypes built so far achieved a COP of 3 to 15 and an efficiency of up to 60% of the Carnot cycle.
Also used as a refrigerant cooling magnetic solid material, environmentally friendly and water based solution as heat transfer fluid, eliminating the need for environmentally harmful chemicals. Last but not least, another advantage would be no noise. In this technology is no longer used compressor (main noise source of the classic technology) and the magnetocaloric material does not touch the magnets in operation, noise is nearly nonexistent. Thus, this technology has the potential to significantly reduce the global consumption of electricity and as a consequence of limiting carbon dioxide emissions thus having a minimal contribution to the warming global climate.
Thus in the first stage magnetocaloric material is placed in the magnetic field and heat (adiabatic magnetization). Then heat is removed by using liquid cooling (heat release in constant magnetic field). The liquid practical magnetocaloric material absorbs heat and cools. In the third stage of the magnetic field is removed the material cools and inverse magnetocaloric effect due, but as he is already partially cooled by liquid temperature falls below its initial temperature (adiabatic demagnetization). In the last stage, the temperature difference is taken and transmitted environment that we want to supercooled (transfer heat in constant magnetic field). Such material temperature increases again up to the initial temperature and the process can be resumed. In lab where I work, LGeCo of the INSA Strasbourg, use permanent magnets and the magnetocaloric material of the rare element called Gadolinium natural. Now our partners are working on some deLantan based alloys, silicon or magnesium that have properties superior thermo-magnetic gadolinium, and low cost.
A drawback of this technology as yet the high price of these magnetocaloric materials and magnets. But it will disappear with the industrialization of this technology because there will be more demand and a decrease in the unit price automatically. Currently there are several labs working in this field there is a fierce competition between. Who will succeed the first to pull the market refrigerators and other cooling equipment based on this technology? France is the project MagCool within which activates the National Institute of Applied Sciences INSA Strasbourg with French company Cooltech and other partners and receive financial support from several investors including funding of 26 million euros from the French government, in the United States there AMES Laboratory, Risø National Laboratory in Denmark Technical University of Denmark and finally in England is Imperial College London.