MAGNETIC HEAT PUMP SYSTEM

• US 20120272666A1
• Filed: 04/25/2012
• Published: 11/01/2012
• Est. Priority Date: 04/28/2011
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Watanabe, Naoki, Nishizawa, Kazutoshi, Yatsuzuka, Shinichi, Morimoto, Tsuyoshi
• Granted Patent: US 9,534,815 B2
• Time in Patent Office: Days
• US Class Current: 62/3.1
• CPC Class Codes: B60H 1/32 Cooling devices B60H1/00478, B60H1/005 take precedence; vehicles adapted to transport refrigerated goods B60P3/20
• CPC Class Codes: B60H 1/32284 comprising two or more secondary circuits, e.g. at evaporator and condenser side
• 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 25/005 using primary and secondary systems
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]

Abstract

In a magnetic heat pump system, in which heat transport medium is heated or cooled by magnetocaloric effect material accommodated in a magnetic heat pump device. A material having a coefficient of thermal conductivity, which is higher than that of the heat transport medium, or a material having a specific heat or a volume specific heat, which is higher than that of the heat transport medium, is mixed in the heat transport medium. A coefficient of thermal conductivity of the heat transport medium is thereby increased so as to increase heating and/or cooling performance of the magnetic heat pump system.

Claims

1. A magnetic heat pump system comprising:

a magnetic heat pump device;

a heat radiating device for radiating heat of heat transport medium, which is discharged from one end of the magnetic heat pump device, to an outside of the heat radiating device; and

a heat absorbing device for absorbing heat from an outside of the heat absorbing device into the heat transport medium discharged from the other end of the magnetic heat pump device,

wherein the magnetic heat pump device comprises;

a container in which magnetocaloric effect material is accommodated and through which the heat transport medium passes;

a magnetic field changing unit for changing degree of magnetic field to be applied to the magnetocaloric effect material;

a working fluid moving unit for moving the heat transport medium in a reciprocating manner in the container, so that the heat transport medium is sucked into the container through one end of the container and the heat transport medium is discharged from the container through the other end of the container and vice versa;

wherein one of the following first and second materials is mixed in the heat transport medium;

first material having a coefficient of thermal conductivity, which is higher than that of the heat transport medium, and

second material having a specific heat or a volume specific heat, which is higher than that of the heat transport medium.

2. The magnetic heat pump system according to claim 1, wherein

the first material having the coefficient of thermal conductivity, which is higher than that of the heat transport medium, is selected from one of the following materials;

carbon nano-tubes, grapheme, alumina, and particles of gold.

3. The magnetic heat pump system according to claim 1, wherein

the second material having the specific heat or the volume specific heat, which is higher than that of the heat transport medium, is composed of latent-heat storage material.

4. The magnetic heat pump system according to claim 3, wherein

the latent-heat storage material is selected from one of the following materials;

paraffin, erythritol, threitol, naphthaline, polyethylene, and stearic acid.

5. The magnetic heat pump system according to claim 1, wherein

minute magnetic material is further mixed in the heat transport medium.

6. The magnetic heat pump system according to claim 1, wherein

minute magnetic material is blended to the material having the coefficient of the thermal conductivity, which is higher than that of the heat transport medium.

7. The magnetic heat pump system according to claim 1, wherein

minute magnetic material is blended to the second material having the specific heat or the volume specific heat, which is higher than that of the heat transport medium.

8. The magnetic heat pump system according to claim 1, wherein

an agitating structure is formed in the container for agitating the heat transport medium.

9. The magnetic heat pump system according to claim 8, wherein

the agitating structure is composed of;

a stirring bar movably accommodated in a rotating space formed in the container, wherein the stirring bar is rotated in accordance with a change of the magnetic field; and

a frame member for forming the rotating space.

10. The magnetic heat pump system according to claim 8, wherein

the agitating structure is formed in the container by multiple columns of the magnetocaloric effect material, wherein the multiple columns are so arranged that the heat transport medium flows through spaces formed between the multiple columns and flow of the heat transport medium is disturbed by the multiple columns.

11. An air conditioning apparatus having the magnetic heat pump system according to claim 1, wherein

the magnetic heat pump device has a first and a second container units provided at both sides of the working fluid moving unit, wherein each of the first and second container units has at least one container,

the working fluid moving unit has;

a rotational shaft driven to rotate by a motor;

multiple cylinders provided around the rotational shaft and respectively connected to each container of the first and second container units; and

multiple pistons movably accommodated in each of the cylinders so that each piston is reciprocated in each cylinder, wherein the working fluid moving unit moves the heat transport medium in such a manner that the heat transport medium is sucked from the container into the corresponding cylinder or the heat transport medium is discharged from the cylinder into the corresponding container,

the magnetic field changing unit, which is provided in each of the first and second container units, is composed of a rotor attached to the rotational shaft and permanent magnets attached to an outer periphery of the rotor,

a first circulation pipe is connected to the first container unit, wherein the heat absorbing device is provided in the first circulation pipe,

a second circulation pipe is connected to the second container unit, wherein the heat radiating device is provided in the second circulation pipe,

the magnetic field changing unit provided in the first container units removes the magnetic field generated by the permanent magnets and to be applied to the magnetocaloric effect material, when the heat transport medium is discharged from the first container unit into the first circulation pipe, and

the magnetic field changing unit provided in the second container unit applies the magnetic field generated by the permanent magnets to the magnetocaloric effect material, when the heat transport medium is discharged from the second container unit into the second circulation pipe.

12. The air conditioning apparatus according to claim 11, wherein

a first bypass pipe is provided in the first circulation pipe, so that the heat transport medium cooled down in the first container unit and discharged from the first container unit is returned to the first container unit without passing through the heat absorbing device,

a second bypass pipe is provided in the second circulation pipe, wherein an outdoor unit is provided in the second bypass pipe so as to absorb heat from outside air into the heat transport medium before the heat transport medium is returned to the second container unit,

the heat transport medium in the first circulation pipe is so controlled as to flow through the first bypass pipe, when the air conditioning apparatus is in its heating operation, and

the heat transport medium in the second circulation pipe is so controlled as to flow through the second bypass pipe, when the air conditioning apparatus is in its cooling operation.

13. The air conditioning apparatus according to claim 12, wherein

a third bypass pipe is provided in the first circulation pipe, wherein an outdoor unit is provided in the third bypass pipe so that the heat transport medium is cooled down by the outdoor unit before the heat transport medium is sucked into the first container unit when the air conditioning apparatus is in the cooling operation.

14. An air conditioning apparatus comprising:

a magnetic heat pump device having a first and a second container units in which magnetocaloric effect material are accommodated and through which heat transport medium passes, magnetic field changing units provided in each of the first and second container units for changing degree of magnetic field to be applied to the magnetocaloric effect material, and a working fluid moving unit provided between the first and second container units for moving the heat transport medium in a reciprocating manner in the respective first and second container units, so that the heat transport medium is sucked into and/or discharged from the respective container units;

a heat absorbing device for absorbing heat from an outside of the heat absorbing device into the heat transport medium discharged from the first container unit;

a heat radiating device for radiating heat of the heat transport medium, which is discharged from the second container unit, to an outside of the heat radiating device;

a first circulation pipe connected to the first container unit, wherein the heat absorbing device is provided in the first circulation pipe; and

a second circulation pipe connected to the second container unit, wherein the heat radiating device is provided in the second circulation pipe,

wherein the magnetic field changing unit, which is provided in each of the first and second container units, is composed of a rotor attached to a rotational shaft and permanent magnets attached to an outer periphery of the rotor,

wherein the magnetic field changing unit provided in the first container unit removes the magnetic field generated by the permanent magnets and to be applied to the magnetocaloric effect material, when the heat transport medium is discharged from the first container unit into the first circulation pipe, and

wherein the magnetic field changing unit provided in the second container unit applies the magnetic field generated by the permanent magnets to the magnetocaloric effect material, when the heat transport medium is discharged from the second container unit into the second circulation pipe.

15. The air conditioning apparatus according to claim 14, wherein

a first bypass pipe is provided in the first circulation pipe, so that the heat transport medium cooled down in the first container unit and discharged from the first container unit is returned to the first container unit without passing through the heat absorbing device,

a second bypass pipe is provided in the second circulation pipe, wherein an outdoor unit is provided in the second bypass pipe so as to absorb heat from outside air into the heat transport medium before the heat transport medium is returned to the second container unit,

the heat transport medium in the first circulation pipe is so controlled as to flow through the first bypass pipe, when the air conditioning apparatus is in its heating operation, and

the heat transport medium in the second circulation pipe is so controlled as to flow through the second bypass pipe, when the air conditioning apparatus is in its cooling operation.

16. The air conditioning apparatus according to claim 15, wherein

a third bypass pipe is provided in the first circulation pipe, wherein an outdoor unit is provided in the third bypass pipe so that the heat transport medium is cooled down by the outdoor unit before the heat transport medium is sucked into the first container unit when the air conditioning apparatus is in the cooling operation.