Process and apparatus to increase the temperature gradient in a thermal generator using magneto-calorific material

• US 8,904,806 B2
• Filed: 03/13/2008
• Issued: 12/09/2014
• Est. Priority Date: 03/19/2007
• Status: Expired due to Fees

• Current Assignee: Cooltech Applications
• Original Assignee: Cooltech Applications S.A.S.
• Inventors: Cramet, Nicolas, Dupin, Jean-Louis, Heitzler, Jean-Claude, Muller, Christian
• Primary Examiner(s): Pettitt, John F
• Assistant Examiner(s): LANDEROS, IGNACIO EMMANUEL
• Application Number:
  US12/531,585
• Publication Number:
  US 20100095686A1
• Time in Patent Office: 2,462 Days
• Field of Search: 62/31, 62/32, 62/33
• 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 2321/0022 with a rotating or otherwise moving magnet
• CPC Class Codes: F25B 2321/0023 with modulation, influencing or enhancing an existing magnetic field
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]

Abstract

A method and an apparatus for increasing the temperature gradient of a magneto-calorific thermal generator comprising magneto-calorific elements subjected to a magnetic field variation. At least one of a pre-heating and pre-cooling of the magneto-calorific elements (60) is carried out to modify the initial temperature before and/or during the magnetic field variation before reaching the maximum and/or minimum field value. The method and apparatus may be employed in heating, tempering, air conditioning, refrigeration and other industrial or domestic applications.

Claims

1. A method of increasing a temperature gradient in a magneto-calorific thermal generator (1) comprising fixed magneto-calorific elements (60) and magnetic means (3) capable of moving, relative to the magneto-calorific elements (60), to alternately supply the magneto-calorific elements to a magnetic field variation between a maximum field value and a minimum field value to change a temperature of the magneto-calorific elements (60), and collector means for collecting at least one of calories and frigories emitted by the magneto-calorific elements (60), the collector means comprising at least one collector circuit (31a, 32a) with at least one heat transfer fluid circulating in at least one circulation channel of the magneto-calorific elements (60), the method comprising the steps of:

circulating the heat transfer fluid in the collector circuit in a direction parallel to the movement of the magnetic means (3); and

circulating the heat transfer fluid in the collector circuit (31a, 32a) at a circulation speed that is greater than the speed of motion of the magnetic means so as to at least one of pre-heating of the magneto-calorific elements (60) of a thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation, before reaching the maximum field value in the thermal module (10), and pre-cooling of the magneto-calorific elements (60) of the thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation, before reaching the minimum field value in the thermal module (10).

2. The method according to claim 1, further comprising the step of arranging the magneto-calorific elements (60) in a shape of a circular sector around a central shaft (2) which carries the magnetic means (3) and facilitates rotation of the magnetic means (3).

3. The method according to claim 1, further comprising the step of circulating a first heat transfer fluid in a first collector circuit (hot) and circulating a second heat transfer fluid in a second collector circuit (cold), with the first heat transfer fluid circulating within the first collector circuit at a circulation speed that is greater than the speed of motion of the magnetic means.

4. The method according to claim 3, further comprising the step of varying the circulation speed of the first heat transfer fluid, in the first collector circuit, via a circulation pump (31b) driven by a control box (31c).

5. The method according to claim 1, further comprising the step of circulating a first heat transfer fluid in a first collector circuit (hot) and circulating a second heat transfer fluid in a second collector circuit (cold), with the second heat transfer fluid circulating within the second collector circuit at a circulation speed that is greater than the speed of motion of the magnetic means.

6. The method according to claim 5, further comprising the step of varying the circulation speed of the second heat transfer fluid in the second collector circuit via a circulation pump (32b) driven by a control box (32c).

7. The method according to claim 1, further comprising in the step of circulating the heat transfer fluid in the collector circuit to collect at least one of the calories and the frigories emitted by the magneto-calorific elements (60) at a circulation speed that is greater than a speed variation of the magnetic field by modulating a speed of motion of the magnetic means.

8. The device according to claim 1, further comprising the step of measuring the circulation speed as a linear speed of movement of the heat transfer fluid.

9. A device for increasing a temperature gradient in a magneto-calorific thermal generator (1) comprising fixed magneto-calorific elements (60) and magnetic means (3) capable of moving relative to the magneto-calorific elements (60) to alternately submit the magneto-calorific elements (60) to a magnetic field varying between a maximum field value and a minimum field value to change the temperature of the magneto-calorific elements (60), and collection means for collecting at least one of calories and frigories emitted by the magneto-calorific elements (60), the collection means comprising at least one circuit (31a, 31b) with at least one heat transfer fluid circulating in at least one circulation channel of the magneto-calorific elements (60),

wherein the heat transfer fluid circulates in a direction parallel to the movement of the magnetic means (3) and the heat transfer fluid circulates in the collector circuit (31a, 32a) at a circulation speed that is greater than the speed of motion of the magnetic means so as to at least one of pre-heating of the magneto-calorific elements (60) of a thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation before reaching a maximum field value, and pre-cooling of the magneto-calorific elements (60) of the thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation before reaching a minimum field value in the thermal module (10).

10. The device according to claim 9, wherein a first heat transfer fluid circulates in a first collector circuit (hot) and a second heat transfer fluid circulates in a second collector circuit (cold), and the circulation means circulates the first heat transfer fluid circulate within the first collector circuit (hot) at a circulation speed that is greater than the speed of motion of the magnetic means.

11. The device according to claim 9, wherein a first heat transfer fluid circulates in a first collector circuit (hot) and a second heat transfer fluid circulates in a second collector circuit (cold), and the circulation means circulates the second heat transfer fluid circulate within the second collector circuit (cold) at a circulation speed that is greater than the speed of motion of the magnetic means.

12. The device according to claim 11, wherein the second collector circuit (cold) comprises a second circulation pump (32b) driven by a control box (32c).

13. The device according to claim 10, wherein the first collector circuit (hot) comprises a first circulation pump (31b) driven by a control box (31c).

14. The device according to claim 9, wherein the thermal generator (1) comprises a rotating shaft (2) carrying magnetic assemblies (3) and an actuator (2a) arranged to control a driving speed of the shaft (2) and create a magnetic field variation speed that is less than the circulation speed of the heat transfer fluid.

15. A method of increasing a temperature gradient in a magneto-calorific thermal generator (1) comprising fixed magneto-calorific elements (60) and magnetic mechanism (3) arranged to alternately supply the magneto-calorific elements to a magnetic field variation between a maximum field value and a minimum field value to change a temperature of the magneto-calorific elements (60), and collecting mechanism for collecting at least one of calories and frigories emitted by the magneto-calorific elements (60), the collecting mechanism comprising at least one collector circuit (31a, 32a) with at least one heat transfer fluid circulating in at least one circulation channel of magneto-calorific elements (60), the method comprising the step of:

circulating the heat transfer fluid in the collector circuit in a direction parallel to the movement of the magnetic means (3); and

circulating the heat transfer fluid in the collector circuit (31a, 32a) at a circulation speed that is greater than the speed of motion of the magnetic means so as to at least one of pre-heating of the magneto-calorific elements (60) of a thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation, before reaching the maximum field value in the thermal module (10), and pre-cooling of the magneto-calorific elements (60) of the thermal module (10) to modify an initial temperature of the magneto-calorific elements (60) at least one of before and during the magnetic field variation, before reaching the minimum field value in the thermal module (10).

16. The method according to claim 15, further comprising the steps of

moving the magnetic mechanism with respect to the magneto-calorific elements such that the magneto-calorific elements are sequentially subjected to the magnetic field variation;

arranging the at least one circulation channel of magneto-calorific elements such that the heat transfer fluid circulates in a direction that is parallel to a direction in which the magneto-calorific elements are sequentially subjected to the magnetic field variation; and

circulating the heat transfer fluid in the at least one circulation channel at a circulation speed that is greater than a speed at which the magneto-calorific elements are sequentially subjected to the magnetic field variation such that the initial temperatures of each of the magneto-calorific elements is sequentially modified before the magneto-calorific elements are sequentially subjected to the magnetic field variation.

17. The method according to claim 15, further comprising the step of measuring the circulation speed as a linear speed of movement of the heat transfer fluid.