Shimmed active magnetic regenerator for use in thermodynamic devices

Abstract

The technology provides a shimmed active magnetic regenerator (SAMR) for use in active magnetic thermodynamic devices. The shimmed active magnetic regenerator comprises a combination of at least one magnetocaloric material and at least one shim comprising at least one passive material, such that when a magnetic field is applied the relative magnetization of the magnetocaloric material in combination with the shim is greater than the relative magnetization of the magnetocaloric material. The SAMR can achieve a relative magnetism of about 1 from a magnetic field less than approximately 3T.

1 . A shimmed active magnetic regenerator (SAMR) for use in active magnetic thermodynamic devices, the shimmed active magnetic regenerator comprising a combination of an at least one magnetocaloric material and an at least one shim comprising at least one passive material, such that when a magnetic field is applied the relative magnetization of the magnetocaloric material in combination with the shim is greater than the relative magnetization of the magnetocaloric material. 
   
   
       2 . The SAMR of  claim 1  wherein the passive material is non-magnetocaloric. 
   
   
       3 . The SAMR of  claim 2  wherein the passive material is selected from the group consisting of iron, steel and nickel-iron alloys. 
   
   
       4 . The SAMR of  claim 3  wherein the passive material is iron. 
   
   
       5 . The SAMR of  claim 1  wherein the magnetocaloric materials are selected from the group consisting of Gd, Tb, Dy, alloys of Gd, Tb and Dy, rare-earth elements, alloys of rare-earth and transition metals. 
   
   
       6 . The SAMR of  claim 3  wherein the magnetocaloric materials are selected from the group consisting of Gd, Tb, Dy, alloys of Gd, Tb and Dy, rare-earth elements, alloys of rare-earth and transition metals. 
   
   
       7 . The SAMR of  claim 4  wherein the magnetocaloric material comprises Gd, an at least one alloy of Gd or a combination of Gd and an at least one alloy of Gd. 
   
   
       8 . The SAMR of  claim 6  wherein the magnetocaloric material is shaped to have a body, the body having a side wall, a warm end and a cold end. 
   
   
       9 . The SAMR of  claim 8  wherein said at least one shim is located proximate to said warm end, said cold end or both said warm and said cold end. 
   
   
       10 . The SAMR of  claim 8  wherein said shim is located within said body. 
   
   
       11 . The SAMR of  claim 8  wherein said shim is proximate to said side wall. 
   
   
       12 . The SAMR of  claim 11  wherein said shim envelopes said side wall. 
   
   
       13 . The SAMR of  claim 8  wherein said shim envelopes said magnetocaloric material. 
   
   
       14 . The SAMR of  claim 1 , wherein said relative magnetization exceeds about 1. 
   
   
       15 . A shimmed active magnetic regenerator (SAMR) for use in active magnetic thermodynamic devices, said shimmed active magnetic regenerator comprising a combination of an at least one magnetocaloric material and an at least one shim comprising at least one passive material, said shim located proximate to said magnetocaloric material. 
   
   
       16 .- 28 . (canceled) 
   
   
       29 . A shimmed active magnetic regenerator (SAMR) for use in active magnetic thermodynamic devices, said shimmed active magnetic regenerator comprising a combination of an active magnetic regenerator (AMR) and an at least one shim comprising at least one passive material, such that when a magnetic field is applied the relative magnetization of the shimmed AMR is greater than the AMR. 
   
   
       30 .- 32 . (canceled) 
   
   
       33 . The SAMR of  claim 29  wherein said AMR is comprised of materials selected from the group consisting of Gd, Tb, Dy, alloys of Gd, Tb and Dy, rare-earth elements, alloys of rare-earth and transition metals. 
   
   
       34 . (canceled) 
   
   
       35 . The SAMR of  claim 29  wherein said AMR is comprised of materials selected from the group consisting of Gd, an at least one alloy of Gd or a combination of Gd and an at least one alloy of Gd. 
   
   
       36 . The SAMR of  claim 35  wherein said AMR is shaped to have a body, said body having a side wall, a warm end and a cold end. 
   
   
       37 . The SAMR of  claim 36  wherein said at least one shim is located proximate to said warm end, said cold end or both said warm and said cold end. 
   
   
       38 .- 40 . (canceled) 
   
   
       41 . The SAMR of  claim 36  wherein said shim envelopes said AMR. 
   
   
       42 . The SAMR of  claim 41 , wherein said relative magnetization exceeds about 1. 
   
   
       43 . The SAMR of  claim 42  wherein said magnetic field is less than approximately 3T. 
   
   
       44 .- 46 . (canceled) 
   
   
       47 . The SAMR of  claim 43  wherein said magnetic field is less than approximately 3T and said relative magnetization exceeds about 1. 
   
   
       48 .- 60 . (canceled)