Experimental study of room temperature magnetic refrigerator using multilayered magnetocaloric materialsExperimental study of room temperature magnetic refrigerator using multilayered magnetocaloric materials Experimental study of room temperature magnetic refrigerator using multilayered magnetocaloric materials
Railway technical research institute has been studying a magnetic refrigerator for trains’ air conditioners. Conventional air conditioners in Japanese trains have a cooling capacity of 25 kW, the electric consumption of 10 kW and the coefficient of performance of 2.5. Hydro-CFCs are used in the conventional air-conditioners. The development of HCFC free systems or the usage of substances which have little greenhouse effect is required because the problem with HCFC is the global warming. Therefore, there are a lot of researches on air-conditioning systems with less influence on the environment. Magnetic refrigeration technology has a potential for high efficiency without use of Freon gases. A prototype magnetic refrigerator has been developed, which consists of fixed active magnetic regenerator (AMR) beds and Halbach arrayed NdFeB magnets with a peak field of 1.5 Tesla rotating over the beds. Each bed was packed with sphere Gd or Gd-based compounds. The system has a maximum cooling capacity of 1.4 kW. Several cascade patterns of the packed materials in the AMR beds were evaluated and a maximum temperature span of 21 K was obtained.