MAGNETIC REGENERATOR, A METHOD OF MAKING A MAGNETIC REGENERATOR, A METHOD OF MAKING AN ACTIVE MAGNETIC REFRIGERATOR AND AN ACTICVE MAGNETIC REFRIGERATOR

• US 20120079834A1
• Filed: 10/10/2011
• Published: 04/05/2012
• Est. Priority Date: 01/12/2005
• Status: Active Grant

• Current Assignee: Technical University of Denmark
• Original Assignee: Technical University of Denmark
• Inventors: DINESEN, Anders Reves, LINDEROTH, Soren, PRYDS, Nini, SMITH, Anders
• Granted Patent: US 8,616,009 B2
• Time in Patent Office: Days
• US Class Current: 62/3.1
• CPC Class Codes: F25B 21/00 Machines, plants or systems, using electric or magnetic effects
• CPC Class Codes: F25B 2321/002 by using magneto-caloric effects
• CPC Class Codes: H01F 1/012 adapted for magnetic entropy change by magnetocaloric effect, e.g. used as magnetic refrigerating material refrigeration systems using magnetic effects F25B21/00
• CPC Class Codes: H01F 41/16 the magnetic material being applied in the form of particles, e.g. by serigraphy , to form thick magnetic films or precursors therefor H01F41/18 -H01F41/24 take precedence
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49359 Cooling apparatus making, e.g., air conditioner, refrigerator

Abstract

The invention provides a method of making a magnetic regenerator for an active magnetic refrigerator, the method comprising: forming a magnetic regenerator from a slurry or a paste containing a magnetocaloric material the magnetic regenerator being formed to have plural paths therethrough for the flow of a heat transfer fluid; and varying the composition of the magnetocaloric material so that the magnetic transition temperature of the magnetic regenerator varies along the paths.

Claims

1. A magnetic refrigerator, comprising:

a magnetic regenerator comprising plural channels made of a ceramic material through which in use a heat transfer fluid is made to flow back and forth, wherein the magnetic transition temperature of the magnetic regenerator varies in the direction of flow of the heat transfer fluid.

2. A magnetic refrigerator according to claim 1, comprising;

a magnet for providing a magnetic field for application and removal from the magnetic regenerator as heat transfer fluid flows back and forth therethrough.

3. A magnetic refrigerator according to claim 1, comprising;

a hot-side heat exchanger for removing heat from the heat transfer fluid once it has flown through the magnetised magnetic regenerator; and

a cold-side heat exchanger for providing heat to the heat transfer fluid once it has flown through the demagnetised magnetic regenerator.

5. A magnetic refrigerator according to claim 1, wherein the channels are tubes of magnetocaloric material, or are longitudinal channels formed within a block of magnetocaloric material.

4. A magnetic regenerator comprising plural paths made of a ceramic material through which in use a heat transfer fluid is made to flow back and forth, wherein the magnetic transition temperature of the magnetic regenerator varies along the paths.

6. A magnetic regenerator according to claim 4, wherein the channels are between plates of magnetocaloric material, the separation of the plates being between 0.1 mm and 0.5 mm.

7. A magnetic refrigerator according to claim 6, wherein the plates have a thickness between 0.1 mm and 0.5 mm.