Magnetic material for magnetic refrigeration apparatus, amr bed, and magnetic refrigeration apparatus

Abstract

There are provided a magnetic material for a magnetic refrigeration apparatus, which improves magnetic refrigeration efficiency by the wide operation temperature range of it, AMR bed using the magnetic material, and a magnetic refrigeration apparatus. The magnetic material is used for the magnetic refrigeration apparatus using a liquid refrigerant, formed by approximately uniformly blending at least two kinds of magnetic particles having different magnetic transition temperatures, and the magnetic particles exhibit an approximately spherical shape with maximum diameter of 0.3 mm or more to 2 mm or less. The AMR bed is filled with the magnetic particles.

1 . A magnetic material for a magnetic refrigeration apparatus comprising:
 first magnetic particles contained in a heaviest weight; and   second magnetic particles contained in a next heaviest weight having a different magnetic transition temperature from that of the first magnetic particles,   wherein, both of the magnetic particles are blended approximately uniformly and exhibit an approximately spherical shape with a maximum diameter of 0.3 mm or more to 2 mm or less.   
   
   
       2 . The material according to  claim 1 , wherein;
 the difference between the magnetic transition temperature of first and second magnetic particles is 1 K or more to less than 10 K; and   the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:2.   
   
   
       3 . The material according to  claim 1 , wherein the difference between the magnetic transition temperature of first and second magnetic particles is 10 K or more to 15 K or less; and
 the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:1.   
   
   
       4 . The material according to  claim 1 , wherein the magnetic particles are Gd (gadolinium) or GdR alloys (R: rear earth elements). 
   
   
       5 . AMR bed filled with a magnetic material for a magnetic refrigeration apparatus, wherein the magnetic material comprises first magnetic particles contained in a heaviest weight and second magnetic particles contained in a next heaviest weight having a different magnetic transition temperature from that of the first magnetic particles, and both of the magnetic particles are blended approximately uniformly and exhibit an approximately spherical shape with a maximum diameter of 0.3 mm or more to 2 mm or less. 
   
   
       6 . The AMR bed according to  claim 5 , wherein a void ratio of the AMR bed is 30% or more to 50% or less. 
   
   
       7 . The AMR bed according to  claim 5 , wherein:
 the difference between the magnetic transition temperature of first and second magnetic particles is 1 K or more to less than 10 K; and   the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:2.   
   
   
       8 . The AMR bed according to  claim 5 , wherein:
 the difference between the magnetic transition temperature of first and second magnetic particles is 10 K or more to 15 K or less; and   the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:1.   
   
   
       9 . The AMR bed according to  claim 5 , wherein the magnetic particles are Gd (gadolinium) or GdR alloys (R: rear earth elements). 
   
   
       10 . A magnetic refrigeration apparatus using a liquid refrigerant comprising:
 AMR bed filled with a magnetic material;   magnetic field generation device for applying and removing a magnetic field to and from the magnetic material;   a cooling block;   a radiating block; and   a refrigerant flow path formed by connecting the AMR bed, the cooling block and the radiating block configured to circulate the liquid refrigerant,   wherein the magnetic material comprises first magnetic particles contained in a heaviest weight and second magnetic particles contained in a next heaviest weight having a different magnetic transition temperature from that of the first magnetic particles, and both of the magnetic particles are blended approximately uniformly and exhibit an approximately spherical shape with a maximum diameter of 0.3 mm or more to 2 mm or less.   
   
   
       11 . The apparatus according to  claim 10 , wherein:
 the difference between the magnetic transition temperature of first and second magnetic particles is 1 K or more to less than 10 K; and   the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:2.   
   
   
       12 . The apparatus according to  claim 10 , wherein:
 the difference between the magnetic transition temperature of first and second magnetic particles is 10 K or more to 15 K or less; and   the first magnetic particles are blended with the second magnetic particles at a weight ratio from 5:5 to 3:1.   
   
   
       13 . The apparatus according to  claim 10 , wherein the magnetic particles are Gd (gadolinium ) or GdR alloys (R: rear earth elements). 
   
   
       14 . The apparatus according to  claim 10 , wherein a void ratio of the AMR bed is 30% or more to 50% or less.