Magneto-caloric thermal diode assembly

Information

  • Patent Grant
  • 10648705
  • Patent Number
    10,648,705
  • Date Filed
    Wednesday, April 18, 2018
    6 years ago
  • Date Issued
    Tuesday, May 12, 2020
    4 years ago
Abstract
A magneto-caloric thermal diode assembly includes a first magneto-caloric cylinder and a second magneto-caloric cylinder. First and second pluralities of thermal stages are stacked along an axial direction between a cold side and a hot side. The second magneto-caloric cylinder and the second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and the first plurality of thermal stages. Each thermal stage of the first and second pluralities of thermal stages includes a plurality of magnets and a non-magnetic ring. The plurality of magnets is distributed along a circumferential direction within the non-magnetic ring in each thermal stage of the first and second pluralities of thermal stages.
Description
FIELD OF THE INVENTION

The present subject matter relates generally to heat pumps, such as magneto-caloric heat pumps.


BACKGROUND OF THE INVENTION

Conventional refrigeration technology typically utilizes a heat pump that relies on compression and expansion of a fluid refrigerant to receive and reject heat in a cyclic manner so as to effect a desired temperature change or transfer heat energy from one location to another. This cycle can be used to receive heat from a refrigeration compartment and reject such heat to the environment or a location that is external to the compartment. Other applications include air conditioning of residential or commercial structures. A variety of different fluid refrigerants have been developed that can be used with the heat pump in such systems.


While improvements have been made to such heat pump systems that rely on the compression of fluid refrigerant, at best such can still only operate at about forty-five percent or less of the maximum theoretical Carnot cycle efficiency. Also, some fluid refrigerants have been discontinued due to environmental concerns. The range of ambient temperatures over which certain refrigerant-based systems can operate may be impractical for certain locations. Other challenges with heat pumps that use a fluid refrigerant exist as well.


Magneto-caloric materials (MCMs), i.e. materials that exhibit the magneto-caloric effect, provide a potential alternative to fluid refrigerants for heat pump applications. In general, the magnetic moments of MCMs become more ordered under an increasing, externally applied magnetic field and cause the MCMs to generate heat. Conversely, decreasing the externally applied magnetic field allows the magnetic moments of the MCMs to become more disordered and allow the MCMs to absorb heat. Some MCMs exhibit the opposite behavior, i.e. generating heat when the magnetic field is removed (which are sometimes referred to as para-magneto-caloric material but both types are referred to collectively herein as magneto-caloric material or MCM). The theoretical Carnot cycle efficiency of a refrigeration cycle based on an MCMs can be significantly higher than for a comparable refrigeration cycle based on a fluid refrigerant. As such, a heat pump system that can effectively use an MCM would be useful.


Challenges exist to the practical and cost competitive use of an MCM, however. In addition to the development of suitable MCMs, equipment that can attractively utilize an MCM is still needed. Currently proposed equipment may require relatively large and expensive magnets, may be impractical for use in e.g., appliance refrigeration, and may not otherwise operate with enough efficiency to justify capital cost.


Accordingly, a heat pump system that can address certain challenges, such as those identified above, would be useful. Such a heat pump system that can also be used in a refrigerator appliance would also be useful.


BRIEF DESCRIPTION OF THE INVENTION

Aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.


In a first example embodiment, a magneto-caloric thermal diode assembly includes a first magneto-caloric cylinder and a second magneto-caloric cylinder. A first plurality of thermal stages is stacked along an axial direction between a cold side and a hot side. A second plurality of thermal stages is stacked along the axial direction between the cold side and the hot side. The first and second pluralities of thermal stages and the first and second magneto-caloric cylinders are configured for relative rotation between the first and second pluralities of thermal stages and the first and second magneto-caloric cylinders. The second magneto-caloric cylinder and the second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and the first plurality of thermal stages. Each thermal stage of the first and second pluralities of thermal stages includes a plurality of magnets and a non-magnetic ring. The plurality of magnets is distributed along a circumferential direction within the non-magnetic ring in each thermal stage of the first and second pluralities of thermal stages.


In a second example embodiment, a magneto-caloric thermal diode assembly includes a first magneto-caloric cylinder and a second magneto-caloric cylinder. A first plurality of thermal stages is stacked along an axial direction between a cold side and a hot side. A second plurality of thermal stages is stacked along the axial direction between the cold side and the hot side. The first and second pluralities of thermal stages and the first and second magneto-caloric cylinders are configured for relative rotation between the first and second pluralities of thermal stages and the first and second magneto-caloric cylinders. The second magneto-caloric cylinder and the second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and the first plurality of thermal stages. Each thermal stage of the first and second pluralities of thermal stages includes a plurality of non-magnetic blocks and a magnetic ring. The plurality of non-magnetic blocks is distributed along a circumferential direction within the magnetic ring in each thermal stage of the first and second pluralities of thermal stages.


These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.





BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.



FIG. 1 is a refrigerator appliance in accordance with an example embodiment of the present disclosure.



FIG. 2 is a schematic illustration of certain components of a heat pump system positioned in the example refrigerator appliance of FIG. 1.



FIG. 3 is a perspective view of a magneto-caloric thermal diode according to an example embodiment of the present subject matter.



FIG. 4 is a section view of the example magneto-caloric thermal diode of FIG. 3.



FIG. 5 is a perspective view of the example magneto-caloric thermal diode of FIG. 3 with certain thermal stages removed from the example magneto-caloric thermal diode.



FIG. 6 is a section view of the example magneto-caloric thermal diode of FIG. 5.



FIG. 7 is a perspective view of the example magneto-caloric thermal diode of FIG. 5 with an insulation layer removed from the example magneto-caloric thermal diode.



FIG. 8 is a schematic view of the certain components of the example magneto-caloric thermal diode of FIG. 3.



FIG. 9 is a schematic view of the certain components of a magneto-caloric thermal diode according to another example embodiment of the present subject matter.



FIG. 10 is a schematic view of the certain components of a magneto-caloric thermal diode according to an additional example embodiment of the present subject matter.





DETAILED DESCRIPTION

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.


Referring now to FIG. 1, an exemplary embodiment of a refrigerator appliance 10 is depicted as an upright refrigerator having a cabinet or casing 12 that defines a number of internal storage compartments or chilled chambers. In particular, refrigerator appliance 10 includes upper fresh-food compartments 14 having doors 16 and lower freezer compartment 18 having upper drawer 20 and lower drawer 22. Drawers 20, 22 are “pull-out” type drawers in that they can be manually moved into and out of freezer compartment 18 on suitable slide mechanisms. Refrigerator 10 is provided by way of example only. Other configurations for a refrigerator appliance may be used as well including appliances with only freezer compartments, only chilled compartments, or other combinations thereof different from that shown in FIG. 1. In addition, the magneto-caloric thermal diode and heat pump system of the present disclosure is not limited to refrigerator appliances and may be used in other applications as well such as e.g., air-conditioning, electronics cooling devices, and others. Thus, it should be understood that while the use of a magneto-caloric thermal diode and heat pump system to provide cooling within a refrigerator is provided by way of example herein, the present disclosure may also be used to provide for heating applications as well.



FIG. 2 is a schematic view of various components of refrigerator appliance 10, including refrigeration compartments 30 (e.g., fresh-food compartments 14 and freezer compartment 18) and a machinery compartment 40. Refrigeration compartment 30 and machinery compartment 40 include a heat pump system 52 having a first or cold side heat exchanger 32 positioned in refrigeration compartment 30 for the removal of heat therefrom. A heat transfer fluid such as e.g., an aqueous solution, flowing within cold side heat exchanger 32 receives heat from refrigeration compartment 30 thereby cooling contents of refrigeration compartment 30.


The heat transfer fluid flows out of cold side heat exchanger 32 by line 44 to magneto-caloric thermal diode 100. As will be further described herein, the heat transfer fluid rejects heat to magneto-caloric material (MCM) in magneto-caloric thermal diode 100. The now colder heat transfer fluid flows by line 46 to cold side heat exchanger 32 to receive heat from refrigeration compartment 30.


Another heat transfer fluid carries heat from the MCM in magneto-caloric thermal diode 100 by line 48 to second or hot side heat exchanger 34. Heat is released to the environment, machinery compartment 40, and/or other location external to refrigeration compartment 30 using second heat exchanger 34. From second heat exchanger 34, the heat transfer fluid returns by line 50 to magneto-caloric thermal diode 100. The above described cycle may be repeated to suitable cool refrigeration compartment 30. A fan 36 may be used to create a flow of air across second heat exchanger 34 and thereby improve the rate of heat transfer to the environment.


A pump or pumps (not shown) cause the heat transfer fluid to recirculate in heat pump system 52. Motor 28 is in mechanical communication with magneto-caloric thermal diode 100 and is operable to provide relative motion between magnets and a magneto-caloric material of magneto-caloric thermal diode 100, as discussed in greater detail below.


Heat pump system 52 is provided by way of example only. Other configurations of heat pump system 52 may be used as well. For example, lines 44, 46, 48, and 50 provide fluid communication between the various components of heat pump system 52 but other heat transfer fluid recirculation loops with different lines and connections may also be employed. Still other configurations of heat pump system 52 may be used as well.


In certain exemplary embodiments, cold side heat exchanger 32 is the only heat exchanger within heat pump system 52 that is configured to cool refrigeration compartments 30. Thus, cold side heat exchanger 32 may be the only heat exchanger within cabinet 12 for cooling fresh-food compartments 14 and freezer compartment 18. Refrigerator appliance 10 also includes features for regulating air flow across cold side heat exchanger 32 and to fresh-food compartments 14 and freezer compartment 18.


As may be seen in FIG. 2, cold side heat exchanger 32 is positioned within a heat exchanger compartment 60 that is defined within cabinet 12, e.g., between fresh-food compartments 14 and freezer compartment 18. Fresh-food compartment 14 is contiguous with heat exchanger compartment 60 through a fresh food duct 62. Thus, air may flow between fresh-food compartment 14 and heat exchanger compartment 60 via fresh food duct 62. Freezer compartment 18 is contiguous with heat exchanger compartment 60 through a freezer duct 64. Thus, air may flow between freezer compartment 18 and heat exchanger compartment 60 via freezer duct 64.


Refrigerator appliance 10 also includes a fresh food fan 66 and a freezer fan 68. Fresh food fan 66 may be positioned at or within fresh food duct 62. Fresh food fan 66 is operable to force air flow between fresh-food compartment 14 and heat exchanger compartment 60 through fresh food duct 62. Fresh food fan 66 may thus be used to create a flow of air across cold side heat exchanger 32 and thereby improve the rate of heat transfer to air within fresh food duct 62. Freezer fan 68 may be positioned at or within freezer duct 64. Freezer fan 68 is operable to force air flow between freezer compartment 18 and heat exchanger compartment 60 through freezer duct 64. Freezer fan 68 may thus be used to create a flow of air across cold side heat exchanger 32 and thereby improve the rate of heat transfer to air within freezer duct 64.


Refrigerator appliance 10 may also include a fresh food damper 70 and a freezer damper 72. Fresh food damper 70 is positioned at or within fresh food duct 62 and is operable to restrict air flow through fresh food duct 62. For example, when fresh food damper 70 is closed, fresh food damper 70 blocks air flow through fresh food duct 62, e.g., and thus between fresh-food compartment 14 and heat exchanger compartment 60. Freezer damper 72 is positioned at or within freezer duct 64 and is operable to restrict air flow through freezer duct 64. For example, when freezer damper 72 is closed, freezer damper 72 blocks air flow through freezer duct 64, e.g., and thus between freezer compartment 18 and heat exchanger compartment 60. It will be understood that the positions of fans 66, 68 and dampers 70, 72 may be switched in alternative exemplary embodiments.


Operation of heat pump system 52 and fresh food fan 66 while fresh food damper 70 is open, allows chilled air from cold side heat exchanger 32 to cool fresh-food compartment 14, e.g., to about forty degrees Fahrenheit (40° F.). Similarly, operation of heat pump system 52 and freezer fan 68 while freezer damper 72 is open, allows chilled air from cold side heat exchanger 32 to cool freezer compartment 18, e.g., to about negative ten degrees Fahrenheit (−10° F.). Thus, cold side heat exchanger 32 may chill either fresh-food compartment 14 or freezer compartment 18 during operation of heat pump system 52. In such a manner, both fresh-food compartments 14 and freezer compartment 18 may be air cooled with cold side heat exchanger 32.



FIGS. 3 through 8 are various views of magneto-caloric thermal diode 200 according to an example embodiment of the present subject matter. Magneto-caloric thermal diode 200 may be used in any suitable heat pump system. For example, magneto-caloric thermal diode 200 may be used in heat pump system 52 (FIG. 2). As discussed in greater detail below, magneto-caloric thermal diode 200 includes features for transferring thermal energy from a cold side 202 of magneto-caloric thermal diode 200 to a hot side 204 of magneto-caloric thermal diode 200. Magneto-caloric thermal diode 200 defines an axial direction A, a radial direction R and a circumferential direction C.


Magneto-caloric thermal diode 200 includes a plurality of thermal stages 210. Thermal stages 210 are stacked along the axial direction A between cold side 202 and hot side 204 of magneto-caloric thermal diode 200. A cold side thermal stage 212 of thermal stages 210 is positioned at cold side 202 of magneto-caloric thermal diode 200, and a hot side thermal stage 214 of thermal stages 210 is positioned at hot side 204 of magneto-caloric thermal diode 200.


Magneto-caloric thermal diode 200 also includes a magneto-caloric cylinder 220 (FIG. 8). In certain example embodiments, thermal stages 210 define a cylindrical slot 211, and magneto-caloric cylinder 220 is positioned within cylindrical slot 211. Thus, e.g., each thermal stage 210 may include an inner section 206 and an outer section 208 that are spaced from each other along the radial direction R by cylindrical slot 211 such that magneto-caloric cylinder 220 is positioned between inner and outer sections 206, 208 of thermal stages 210 along the radial direction R. Thermal stages 210 and magneto-caloric cylinder 220 are configured for relative rotation between thermal stages 210 and magneto-caloric cylinder 220. Thermal stages 210 and magneto-caloric cylinder 220 may be configured for relative rotation about an axis X that is parallel to the axial direction A. As an example, magneto-caloric cylinder 220 may be coupled to motor 26 such that magneto-caloric cylinder 220 is rotatable relative to thermal stages 210 about the axis X within cylindrical slot 211 with motor 26. In alternative exemplary embodiments, thermal stages 210 may be coupled to motor 26 such that thermal stages 210 are rotatable relative to magneto-caloric cylinder 220 about the axis X with motor 26.


During relative rotation between thermal stages 210 and magneto-caloric cylinder 220, magneto-caloric thermal diode 200 transfers heat from cold side 202 to hot side 204 of magneto-caloric thermal diode 200. In particular, during relative rotation between thermal stages 210 and magneto-caloric cylinder 220, cold side thermal stage 212 may absorb heat from fresh-food compartments 14 and/or freezer compartment 18, and hot side thermal stage 214 may reject heat to the ambient atmosphere about refrigerator appliance 10.


Each of the thermal stages 210 includes a plurality of magnets 230 and a non-magnetic ring 240. Magnets 230 are distributed along the circumferential direction C within non-magnetic ring 240 in each thermal stage 210. In particular, magnets 230 may be spaced from non-magnetic ring 240 along the radial direction R and the circumferential direction C within each thermal stage 210. For example, each of the thermal stages 210 may include insulation 232, and insulation 232 may be positioned between magnets 230 and non-magnetic ring 240 along the radial direction R and the circumferential direction C within each thermal stage 210. Insulation 232 may limit conductive heat transfer between magnets 230 and non-magnetic ring 240 within each thermal stage 210. As another example, magnets 230 may be spaced from non-magnetic ring 240 along the radial direction R and the circumferential direction C by a gap within each thermal stage 210. The gap between magnets 230 and non-magnetic ring 240 within each thermal stage 210 may limit or prevent conductive heat transfer between magnets 230 and non-magnetic ring 240 within each thermal stage 210.


It will be understood that the arrangement magnets 230 and non-magnetic ring 240 may be flipped in alternative example embodiments. Thus, e.g., a steel and magnet ring may be thermally separate from non-magnetic blocks, e.g., aluminum blocks, within each thermal stage 210. Operation magneto-caloric thermal diode 200 is the same in such configuration.


As may be seen from the above, thermal stages 210 may include features for limiting heat transfer along the radial direction R and the circumferential direction C within each thermal stage 210. Conversely, thermal stages 210 may be arranged to provide a flow path for thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 200. Such arrangement of thermal stages 210 is discussed in greater detail below.


As noted above, thermal stages 210 includes cold side thermal stage 212 at cold side 202 of magneto-caloric thermal diode 200 and hot side thermal stage 214 at hot side 204 of magneto-caloric thermal diode 200. Thus, cold side thermal stage 212 and hot side thermal stage 214 may correspond to the terminal ends of the stack of thermal stages 210. In particular, cold side thermal stage 212 and hot side thermal stage 214 may be positioned opposite each other along the axial direction A on the stack of thermal stages 210. The other thermal stages 210 are positioned between cold side thermal stage 212 and hot side thermal stage 214 along the axial direction A. Thus, e.g., interior thermal stages 216 (i.e., the thermal stages 210 other than cold side thermal stage 212 and hot side thermal stage 214) are positioned between cold side thermal stage 212 and hot side thermal stage 214 along the axial direction A.


Each of the interior thermal stages 216 is positioned between a respective pair of thermal stages 210 along the axial direction A. One of the respective pair of thermal stages 210 is positioned closer to cold side 202 along the axial direction A, and the other of the respective pair of thermal stages 210 is positioned closer to hot side 204 along the axial direction A. For example, a first one 217 of interior thermal stages 216 is positioned between hot side thermal stage 214 and a second one 218 of interior thermal stages 216 along the axial direction A. Similarly, second one 218 of interior thermal stages 216 is positioned between first one 217 of interior thermal stages 216 and a third one 219 of interior thermal stages 216 along the axial direction A.


Each of the interior thermal stages 216 is arranged to provide a flow path for thermal energy along the axial direction A from cold side thermal stage 212 to hot side thermal stage 214. In particular, magnets 230 of each of interior thermal stages 216 may be spaced from non-magnetic ring 240 of the one of the respective pair of thermal stages 210 along the axial direction A. Thus, e.g., magnets 230 of first one 217 of interior thermal stages 216 may be spaced from non-magnetic ring 240 of second one 218 of interior thermal stages 216 along the axial direction A. Similarly, magnets 230 of second one 218 of interior thermal stages 216 may be spaced from non-magnetic ring 240 of third one 219 of interior thermal stages 216 along the axial direction A. Hot side thermal stage 214 may also be arranged in such a manner.


By spacing magnets 230 of each of interior thermal stages 216 from non-magnetic ring 240 of the one of the respective pair of thermal stages 210 along the axial direction A, conductive heat transfer along the axial direction A from magnets 230 of each of interior thermal stages 216 to non-magnetic ring 240 of an adjacent one of thermal stages 210 towards cold side 202 along the axial direction A may be limited or prevented. In certain example embodiments, magneto-caloric thermal diode 200 may include insulation 250. Magnets 230 of each of interior thermal stages 216 may be spaced from non-magnetic ring 240 of the one of the respective pair of thermal stages 210 along the axial direction A by insulation 250. Insulation 250 may limit conductive heat transfer along the axial direction A from magnets 230 of each of interior thermal stages 216 to non-magnetic ring 240 of an adjacent one of thermal stages 210 towards cold side 202 along the axial direction A.


Magnets 230 of each of interior thermal stages 216 may also be in conductive thermal contact with non-magnetic ring 240 of the other of the respective pair of thermal stages 210. Thus, e.g., magnets 230 of first one 217 of interior thermal stages 216 may be in conductive thermal contact with non-magnetic ring 240 of hot side thermal stage 214. Similarly, magnets 230 of second one 218 of interior thermal stages 216 may be in conductive thermal contact with non-magnetic ring 240 of first one 217 of interior thermal stages 216. Cold side thermal stage 212 may also be arranged in such a manner.


By placing magnets 230 of each of interior thermal stages 216 in conductive thermal contact with non-magnetic ring 240 of the other of the respective pair of thermal stages 210, thermal energy flow along the axial direction A towards hot side 204 may be facilitated, e.g., relative to towards cold side 202. In certain example embodiments, magnets 230 of each of interior thermal stages 216 may be positioned to directly contact non-magnetic ring 240 of the other of the respective pair of thermal stages 210. For example, non-magnetic ring 240 of the other of the respective pair of thermal stages 210 may include projections 242 that extend along the axial direction A to magnets 230 of each of interior thermal stages 216.


The above described arrangement of thermal stages 210 may provide a flow path for thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 200 during relative rotation between thermal stages 210 and magneto-caloric cylinder 220. Operation of magneto-caloric thermal diode 200 to transfer thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 200 will now be described in greater detail below.


Magnets 230 of thermal stages 210 produce a magnetic field. Conversely, non-magnetic rings 240 do not produce a magnetic field or produce a negligible magnetic field relative to magnets 230. Thus, each of the magnets 230 may correspond to a high magnetic field zone, and the portion of non-magnetic rings 240 between magnets 230 along the circumferential direction C within each thermal stage 210 may correspond to a low magnetic field zone. During relative rotation between thermal stages 210 and magneto-caloric cylinder 220, magneto-caloric cylinder 220 may be sequentially exposed to the high magnetic field zone at magnets 230 and the low magnetic field zone at non-magnetic rings 240.


Magneto-caloric cylinder 220 includes a magneto-caloric material that exhibits the magneto-caloric effect, e.g., when exposed to the magnetic field from magnets 230 of thermal stages 210. The caloric material may be constructed from a single magneto-caloric material or may include multiple different magneto-caloric materials. By way of example, refrigerator appliance 10 may be used in an application where the ambient temperature changes over a substantial range. However, a specific magneto-caloric material may exhibit the magneto-caloric effect over only a much narrower temperature range. As such, it may be desirable to use a variety of magneto-caloric materials within magneto-caloric cylinder 220 to accommodate the wide range of ambient temperatures over which refrigerator appliance 10 and/or magneto-caloric thermal diode 200 may be used.


Accordingly, magneto-caloric cylinder 220 can be provided with zones of different magneto-caloric materials. Each such zone may include a magneto-caloric material that exhibits the magneto-caloric effect at a different temperature or a different temperature range than an adjacent zone along the axial direction A of magneto-caloric cylinder 220. By configuring the appropriate number sequence of zones of magneto-caloric material, magneto-caloric thermal diode 200 can be operated over a substantial range of ambient temperatures.


As noted above, magneto-caloric cylinder 220 includes magneto-caloric material that exhibits the magneto-caloric effect. During relative rotation between thermal stages 210 and magneto-caloric cylinder 220, the magneto-caloric material in magneto-caloric cylinder 220 is sequentially exposed to the high magnetic field zone at magnets 230 and the low magnetic field zone at non-magnetic rings 240. When the magneto-caloric material in magneto-caloric cylinder 220 is exposed to the high magnetic field zone at magnets 230, the magnetic field causes the magnetic moments of the magneto-caloric material in magneto-caloric cylinder 220 to orient and to increase (or alternatively decrease) in temperature such that the magneto-caloric material in magneto-caloric cylinder 220 rejects heat to magnets 230. Conversely, when the magneto-caloric material in magneto-caloric cylinder 220 is exposed to the low magnetic field zone at non-magnetic rings 240, the decreased magnetic field causes the magnetic moments of the magneto-caloric material in magneto-caloric cylinder 220 to disorient and to decrease (or alternatively increase) in temperature such that the magneto-caloric material in magneto-caloric cylinder 220 absorbs heat from non-magnetic rings 240. By rotating through the high and low magnetic field zones, magneto-caloric cylinder 220 may transfer thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 200 by utilizing the magneto-caloric effect of the magneto-caloric material in magneto-caloric cylinder 220.


As noted above, the high magnetic field zones at magnets 230 in each of thermal stages 210 (e.g., other than hot side thermal stage 214) is in conductive thermal contact with the low magnetic field zone at the non-magnetic ring 240 of an adjacent thermal stages 210 in the direction of hot side 204 along the axial direction A. Thus, the non-magnetic ring 240 of the adjacent thermal stages 210 in the direction of hot side 204 may absorb heat from the high magnetic field zones at magnets 230 in each of thermal stages 210. Thus, thermal stages 210 are arranged to encourage thermal energy flow through thermal stages 210 from cold side 202 towards hot side 204 along the axial direction A during relative rotation between thermal stages 210 and magneto-caloric cylinder 220.


Conversely, the high magnetic field zones at magnets 230 in each of thermal stages 210 (e.g., other than cold side thermal stage 212) is spaced from the low magnetic field zone at the non-magnetic ring 240 of an adjacent thermal stages 210 in the direction of cold side 202 along the axial direction A. Thus, the non-magnetic ring 240 of the adjacent thermal stages 210 in the direction of cold side 202 is thermally isolated from the high magnetic field zones at magnets 230 in each of thermal stages 210. Thus, thermal stages 210 are arranged to discourage thermal energy flow through thermal stages 210 from hot side 204 towards cold side 202 along the axial direction A during relative rotation between thermal stages 210 and magneto-caloric cylinder 220.


Magneto-caloric thermal diode 200 may include a suitable number of thermal stages 210. For example, thermal stages 210 may include nine thermal stages as shown in FIGS. 3 and 4. In alternative example embodiments, thermal stages 210 may include no less than seven thermal stages. Such number of thermal stages 210 may advantageously permit magneto-caloric cylinder 220 to include a corresponding number of zones with different magneto-caloric materials and thereby allow magneto-caloric thermal diode 200 to operate over a wide range of ambient temperatures as discussed above. Magneto-caloric thermal diode 200 may have an odd number of thermal stages 210.


Each of magnets 230 in thermal stages 210 may be formed as a magnet pair 236. One of magnet pair 236 may be mounted to or positioned at inner section 206 of each thermal stage 210, and the other of magnet pair 236 may be mounted to or positioned at outer section 208 of each thermal stage 210. Thus, magneto-caloric cylinder 220 may be positioned between the magnets of magnet pair 236 along the radial direction Rat cylindrical slot 211. A positive pole of one of magnet pair 236 and a negative pole of other of magnet pair 236 may face magneto-caloric cylinder 220 along the radial direction R at cylindrical slot 211.


Cylindrical slot 211 may be suitably sized relative to magneto-caloric cylinder 220 to facilitate efficient heat transfer between thermal stages 210 and magneto-caloric cylinder 220. For example, cylindrical slot 211 may have a width W along the radial direction R, and magneto-caloric cylinder 220 may having a thickness T along the radial direction R within cylindrical slot 211. The width W of cylindrical slot 211 may no more than five hundredths of an inch (0.05″) greater than the thickness T of magneto-caloric cylinder 220 in certain example embodiments. For example, the width W of cylindrical slot 211 may about one hundredth of an inch (0.01″) greater than the thickness T of magneto-caloric cylinder 220 in certain example embodiments. As used herein, the term “about” means within five thousandths of an inch (0.005″) when used in the context of radial thicknesses and widths. Such sizing of cylindrical slot 211 relative to magneto-caloric cylinder 220 can facilitate efficient heat transfer between thermal stages 210 and magneto-caloric cylinder 220.


Each thermal stage 210 may include a suitable number of magnets 230. For example, each thermal stage 210 may include no less than ten (10) magnets 230 in certain example embodiments. With such a number of magnets 230, may advantageously improve performance of magneto-caloric thermal diode 200, e.g., by driving a larger temperature difference between cold side 202 and hot side 204 relative to a smaller number of magnets 230.


Magnets 230 may also be uniformly spaced apart along the circumferential direction C within the non-magnetic ring 240 in each of thermal stages 210. Further, each of thermal stages 210 may be positioned at a common orientation with every other one of thermal stages 210 within the stack of thermal stages 210. Thus, e.g., first one 217 of interior thermal stages 216 may be positioned at a common orientation with third one 219 of interior thermal stages 216, and hot side thermal stage 214 may be positioned at a common orientation with second one 218 of interior thermal stages 216. As may be seen from the above, the common orientation may sequentially skip one thermal stage 214 with the stack of thermal stages 210. Between adjacent thermal stages 210 within the stack of thermal stages 210, each magnet 230 of thermal stages 210 may be positioned equidistance along the circumferential direction C from a respective pair of magnets 230 in adjacent thermal stages 210.


The non-magnetic rings 240 of thermal stage 210 may be constructed of or with a suitable non-magnetic material. For example, the non-magnetic rings 240 of thermal stage 210 may be constructed of or with aluminum in certain example embodiments. In alternative example embodiments, the non-magnetic rings 240 of thermal stage 210 may be constructed of or with brass, bronze, etc.


Magneto-caloric thermal diode 200 may also include one or more heat exchangers 260. In FIG. 3, heat exchanger 260 is shown positioned at the cold side 202 such that heat exchanger 260 absorbs heat from cold side thermal stage 212. A heat transfer fluid may flow between heat exchanger 260 and cold side heat exchanger 32 via lines 44, 46 as discussed above. Another heat exchanger may be positioned hot side 204 such that a heat transfer fluid may flow between the heat exchanger and hot side heat exchanger 34 via lines 48, 50 as discussed above. The heat exchangers (including heat exchanger 260) may be solid-liquid heat exchangers with a port for heat transfer fluid. Alternatively, the heat exchangers could be direct to solid-gas heat exchangers.



FIG. 9 is a schematic view of the certain components of a magneto-caloric thermal diode 300 according to another example embodiment of the present subject matter. As shown in FIG. 9, magneto-caloric thermal diode 300 includes numerous common components with magneto-caloric thermal diode 200. Thus, the description of magneto-caloric thermal diode 200 provided above is applicable to magneto-caloric thermal diode 300 except as otherwise noted. In addition, magneto-caloric thermal diode 200 may include one or more of the aspects of magneto-caloric thermal diode 300 discussed below.


In magneto-caloric thermal diode 300, magneto-caloric cylinder 220 includes a plurality of magneto-caloric stages 222. Magneto-caloric stages 222 are distributed along the axial direction A within magneto-caloric cylinder 220. Each of magneto-caloric stages 222 may have a different magneto-caloric material. For example, the respective magneto-caloric material within each of magneto-caloric stages 222 may be selected such that the Currie temperature of the magneto-caloric materials decreases from hot side 204 to cold side 202 along the axial direction A. In such a manner, a cascade of magneto-caloric materials may be formed within magneto-caloric cylinder 220 along the axial direction A.


Each of magneto-caloric stages 222 may also have a respective length along the axial direction A. In particular, a length LM1 of a first one 224 of magneto-caloric stages 222 may be different than the length LM2 of a second one 226 of magneto-caloric stages 222. It will be understood that each magneto-caloric stage 222 may have a different length in the manner described above for first one 224 and second one 226 of magneto-caloric stages 222 in certain example embodiments. However, in alternative example embodiments, one or more of magneto-caloric stages 222 may have a common length with first one 224 or second one 226 of magneto-caloric stages 222.


Each of thermal stages 210 also having a respective length along the axial direction A. The length of each of thermal stages 210 corresponds to a respective one of magneto-caloric stages 222. Thus, each of thermal stages 210 may be sized to match the respective one of magneto-caloric stages 222 along the axial direction A. The respective one of magneto-caloric stages 222 is disposed with each thermal stage 210.


The length of each of magneto-caloric stages 222 along the axial direction A may be selected to assist with matching heat transfer power, e.g., such that each of magneto-caloric stages 222 accepts heat to one adjacent magneto-caloric stage 222 and rejects heat to the other adjacent magneto-caloric stage 222 along the axial direction A. Within each magneto-caloric stage 222, the rejected heat may be slightly more than the accepted heat based on stage efficiency, and the length of each of magneto-caloric stages 222 along the axial direction A may be selected to complement the efficiency of each magneto-caloric stage 222.


As an example, the length of each of magneto-caloric stages 222 may correspond to a respective Curie temperature spacing between adjacent magneto-caloric stages 222. In particular, the Curie temperature spacing for the first one 224 of magneto-caloric stages 222 may be greater than the Curie temperature spacing for the second one 226 of magneto-caloric stages 222. Thus, the length LM1 of first one 224 of magneto-caloric stages 222 may be greater than the length of LM2 of second one 226 of magneto-caloric stages 222, e.g., in proportion to the difference between the Curie temperature spacing. As may be seen from the above, magneto-caloric stages 222 with larger Curie temperature spacing between adjacent magneto-caloric stages 222 may advantageously have an increased length along the axial direction A relative to magneto-caloric stages 222 with smaller Curie temperature spacing between adjacent magneto-caloric stages 222.


As another example, the length of each of magneto-caloric stages 222 may correspond to an adiabatic temperature change (i.e., the strength) of the magneto-caloric stage 222. In particular, the adiabatic temperature change of the first one 224 of magneto-caloric stages 222 may be less than the adiabatic temperature change of the second one 226 of magneto-caloric stages 222. Thus, the length LM1 of first one 224 of magneto-caloric stages 222 may be greater than the length of LM2 of second one 226 of magneto-caloric stages 222, e.g., in proportion to the difference between the adiabatic temperature changes. As may be seen from the above, weaker magneto-caloric stages 222 may advantageously have an increased length along the axial direction A relative to stronger magneto-caloric stages 222.


As an additional example, the length of hot side thermal stage 214 along the axial direction A may be greater than the length of cold side thermal stage 212 along the axial direction A. Thus, magneto-caloric stages 222 at or adjacent hot side 204 may be longer along the axial direction A relative to magneto-caloric stages 222 at or adjacent cold side 202. In such a manner, magneto-caloric thermal diode 300 may advantageously configured to account for losses in magneto-caloric stages 222, e.g., where rejected heat is greater than accepted heat.


Magneto-caloric thermal diode 300 also includes multiple magneto-caloric cylinders 220 and multiple stacks of thermal stages 210 nested concentrically within each other. In particular, magneto-caloric thermal diode 300 includes a first magneto-caloric cylinder 310 and a second magneto-caloric cylinder 312. Second magneto-caloric cylinder 312 is positioned within first magneto-caloric cylinder 310 along the radial direction R. Magneto-caloric thermal diode 300 also includes a first plurality of thermal stages 320 and a second plurality of thermal stages 322. First thermal stages 320 are stacked along the axial direction A between cold side 202 and hot side 204. Second thermal stages 322 are also stacked along the axial direction A between cold side 202 and hot side 204. First thermal stages 320 are positioned within second thermal stages 322 along the radial direction R.


First and second thermal stages 320, 322 and first and second magneto-caloric cylinders 310, 312 are configured for relative rotation between first and second thermal stages 320, 322 and first and second magneto-caloric cylinders 310, 312. First and second thermal stages 320, 322 and first and second magneto-caloric cylinders 310, 312 may be configured for relative rotation about the axis X that is parallel to the axial direction A. As an example, first and second magneto-caloric cylinders 310, 312 may be coupled to motor 26 such that first and second magneto-caloric cylinders 310, 312 are rotatable relative to first and second thermal stages 320, 322 about the axis X with motor 26. In alternative exemplary embodiments, first and second thermal stages 320, 322 may be coupled to motor 26 such that first and second thermal stages 320, 322 are rotatable relative to first and second magneto-caloric cylinders 310, 312 about the axis X with motor 26.


First thermal stages 320 define a first cylindrical slot 324, and first magneto-caloric cylinder 310 is received within first cylindrical slot 324. Second thermal stages 322 define a second cylindrical slot 326, and second magneto-caloric cylinder 312 is received within second cylindrical slot 326. Second cylindrical slot 326 is positioned inward of first cylindrical slot 324 along the radial direction R.


First magneto-caloric cylinder 310 and first thermal stages 320 operate in the manner described above for thermal stages 210 and magneto-caloric cylinder 220 to transfer thermal energy along the axial direction A from cold side 202 to hot side 204. Similarly, second magneto-caloric cylinder 312 and second thermal stages 322 also operate in the manner described above for thermal stages 210 and magneto-caloric cylinder 220 to transfer thermal energy along the axial direction A from cold side 202 to hot side 204.


Second magneto-caloric cylinder 312 and second thermal stages 322 are nested concentrically within first magneto-caloric cylinder 310 and first thermal stages 320. In such a manner, magneto-caloric thermal diode 300 may include components for operating as multiple magneto-caloric thermal diodes 200 nested concentrically. First and second magneto-caloric cylinders 310, 312 may have identical cascades of magneto-caloric materials along the axial direction A. Thus, e.g., first and second magneto-caloric cylinders 310, 312 may have identical magneto-caloric materials along the radial direction R. By nesting second thermal stage 322 concentrically within first thermal stage 320, a total cooling power of magneto-caloric thermal diode 300 may be increased relative to non-nested magneto-caloric thermal diodes.


First and second thermal stages 320, 322 may be arranged to provide a flow path for thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 300 in the manner described above for magneto-caloric thermal diode 200. For example, each of first thermal stages 320 includes magnets 230 and non-magnetic ring 240, and each of second thermal stages 322 includes magnets 230 and non-magnetic ring 240. Magnets 230 and non-magnetic ring 240 may be arranged within first thermal stages 320 in the manner described above for magnets 230 and non-magnetic ring 240 of magneto-caloric thermal diode 200. Magnets 230 and non-magnetic ring 240 may also be arranged within second thermal stages 322 in the manner described above for magnets 230 and non-magnetic ring 240 of magneto-caloric thermal diode 200.


Each non-magnetic ring 240 within first thermal stages 320 may be in conductive thermal contact with a respective non-magnetic ring 240 within second thermal stages 322 along the radial direction R. For example, each non-magnetic ring 240 within first thermal stages 320 may be integral (e.g., at least partially formed from a single piece of material) with the respective non-magnetic ring 240 within second thermal stages 322 along the radial direction R. By placing each non-magnetic ring 240 within first thermal stages 320 in conductive thermal contact with the respective non-magnetic ring 240 within second thermal stages 322, thermal energy flow along the radial direction R between first and second thermal stages 320, 322.



FIG. 10 is a schematic view of the certain components of a magneto-caloric thermal diode 400 according to an additional example embodiment of the present subject matter. As shown in FIG. 10, magneto-caloric thermal diode 400 includes numerous common components with magneto-caloric thermal diodes 200, 300. Thus, the description of magneto-caloric thermal diodes 200, 300 provided above is applicable to magneto-caloric thermal diode 400 except as otherwise noted. In addition, magneto-caloric thermal diodes 200, 300 may include one or more of the aspects of magneto-caloric thermal diode 400 discussed below.


Like magneto-caloric thermal diode 300, magneto-caloric thermal diode 400 includes multiple magneto-caloric cylinders 220 and multiple stacks of thermal stages 210 nested concentrically within each other. In particular, magneto-caloric thermal diode 400 includes a first magneto-caloric cylinder 410 and a second magneto-caloric cylinder 412. Second magneto-caloric cylinder 412 is positioned within first magneto-caloric cylinder 410 along the radial direction R. Magneto-caloric thermal diode 400 also includes a first plurality of thermal stages 420 and a second plurality of thermal stages 422. First thermal stages 420 are stacked along the axial direction A between cold side 202 and hot side 204. Second thermal stages 422 are also stacked along the axial direction A between cold side 202 and hot side 204. First thermal stages 420 are positioned within second thermal stages 422 along the radial direction R. First and second thermal stages 420, 422 and first and second magneto-caloric cylinders 410, 412 are configured for relative rotation between first and second thermal stages 420, 422 and first and second magneto-caloric cylinders 410, 412.


Second magneto-caloric cylinder 412 and second thermal stages 422 are nested concentrically within first magneto-caloric cylinder 410 and first thermal stages 420. In such a manner, magneto-caloric thermal diode 400 may include components for operating as multiple magneto-caloric thermal diodes 200 nested concentrically. First and second magneto-caloric cylinders 410, 412 may have different cascades of magneto-caloric materials along the axial direction A. Thus, e.g., first and second magneto-caloric cylinders 410, 412 may have different magneto-caloric materials along the radial direction R. By nesting second thermal stage 422 concentrically within first thermal stage 420, a total temperature span of magneto-caloric thermal diode 400 relative to non-nested magneto-caloric thermal diodes.


First and second thermal stages 420, 422 may be arranged to provide a flow path for thermal energy along the axial direction A from cold side 202 to hot side 204 of magneto-caloric thermal diode 400 in the manner described above for magneto-caloric thermal diode 200. For example, each of first thermal stages 420 includes magnets 230 and non-magnetic ring 240, and each of second thermal stages 422 includes magnets 230 and non-magnetic ring 240. Magnets 230 and non-magnetic ring 240 may be arranged within first thermal stages 420 in the manner described above for magnets 230 and non-magnetic ring 240 of magneto-caloric thermal diode 200. Magnets 230 and non-magnetic ring 240 may also be arranged within second thermal stages 422 in a similar manner to that described above for magnets 230 and non-magnetic ring 240 of magneto-caloric thermal diode 200 except that the arrangement of second thermal stage 422 may be reversed along the axial direction A.


In addition, the non-magnetic ring 240 in the one of first thermal stages 420 at cold side 202 may be in conductive thermal contact with the non-magnetic ring 240 in the one of second thermal stages 422 at cold side 202 along the radial direction R. For example, the non-magnetic ring 240 in the one of first thermal stages 420 at cold side 202 may be integral (e.g., at least partially formed from a single piece of material) with the one of second thermal stages 422 at cold side 202 along the radial direction R. By placing the non-magnetic ring 240 in the one of first thermal stages 420 at cold side 202 in conductive thermal contact with the one of second thermal stages 422 at cold side 202, thermal energy flow along the radial direction R between first and second thermal stages 420, 422 at cold side 202.


Other than at cold side 202, each non-magnetic ring 240 in first thermal stages 420 may be spaced from a respective non-magnetic ring 240 in second thermal stages 422 along the radial direction R. For example, other than at cold side 202, each non-magnetic ring 240 in first thermal stages 420 may be spaced from the respective non-magnetic ring 240 in second thermal stages 422 along the radial direction R by insulation 430. By spacing each non-magnetic ring 240 in first thermal stages 420 from the respective non-magnetic ring 240 in second thermal stages 422 other than at cold side 202, thermal energy flow along the radial direction R between first and second thermal stages 420, 422 may be limited.


This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims
  • 1. A magneto-caloric thermal diode assembly, comprising: a first magneto-caloric cylinder;a first plurality of thermal stages stacked along an axial direction between a cold side and a hot side;a second magneto-caloric cylinder; anda second plurality of thermal stages stacked along the axial direction between the cold side and the hot side,wherein the first plurality of thermal stages and the first magneto-caloric cylinder configured for relative rotation between the first plurality of thermal stages and the first magneto-caloric cylinder,the second plurality of thermal stages and the second magneto-caloric cylinder configured for relative rotation between the second plurality of thermal stages and the second magneto-caloric cylinder,the second magneto-caloric cylinder and the second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and the first plurality of thermal stages, andeach thermal stage of the first and second pluralities of thermal stages comprises a plurality of magnets and a non-magnetic ring, the plurality of magnets in each of the thermal stages of the first and second pluralities of thermal stages distributed along a circumferential direction within the non-magnetic ring in each of the thermal stages of the first and second pluralities of thermal stages.
  • 2. The magneto-caloric thermal diode assembly of claim 1, wherein: a cold side thermal stage of the first plurality of thermal stages is positioned at the cold side;a hot side thermal stage of the first plurality of thermal stages is positioned at the hot side;each of the first plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is positioned between a respective pair of the first plurality of thermal stages along the axial direction;one of the respective pair of the first plurality of thermal stages is positioned closer to the cold side along the axial direction;the other of the respective pair of the first plurality of thermal stages is positioned closer to the hot side along the axial direction;the plurality of magnets of each of the first plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is spaced from the non-magnetic ring of the one of the respective pair of the first plurality of thermal stages along the axial direction; andthe plurality of magnets of each of the first plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is in conductive thermal contact with the non-magnetic ring of the other of the respective pair of the first plurality of thermal stages.
  • 3. The magneto-caloric thermal diode assembly of claim 2, wherein the plurality of magnets of each of the first plurality of thermal stages between the cold side thermal stage and the hot side thermal stage is spaced from the non-magnetic ring of the one of the respective pair of the first plurality of thermal stages along the axial direction by insulation.
  • 4. The magneto-caloric thermal diode assembly of claim 1, further comprising a heat exchanger positioned at the cold side.
  • 5. The magneto-caloric thermal diode assembly of claim 1, wherein the plurality of magnets is spaced from the non-magnetic ring along the radial direction and the circumferential direction within each thermal stage of the first and second pluralities of thermal stages.
  • 6. The magneto-caloric thermal diode assembly of claim 5, wherein each thermal stage of the first and second pluralities of thermal stages further comprises insulation positioned between the plurality of magnets and the non-magnetic ring along the radial direction and the circumferential direction.
  • 7. The magneto-caloric thermal diode assembly of claim 1, wherein the non-magnetic ring is an aluminum ring.
  • 8. The magneto-caloric thermal diode assembly of claim 1, wherein the plurality of magnets are uniformly spaced apart along the circumferential direction within the non-magnetic ring in each thermal stage of the first and second pluralities of thermal stages.
  • 9. The magneto-caloric thermal diode assembly of claim 8, wherein each of the plurality of thermal stages comprises no less than ten magnets.
  • 10. The magneto-caloric thermal diode assembly of claim 1, wherein the first and second pluralities of thermal stages and the first and second magneto-caloric cylinders are configured for relative rotation about an axis that is parallel to the axial direction.
  • 11. The magneto-caloric thermal diode assembly of claim 1, wherein the plurality of magnets and the non-magnetic ring of each of the first plurality of thermal stages collectively define a first cylindrical slot, the first magneto-caloric cylinder positioned within the first cylindrical slot, the plurality of magnets and the non-magnetic ring of each of the second plurality of thermal stages collectively define a second cylindrical slot, the second magneto-caloric cylinder positioned within the second cylindrical slot, the second cylindrical slot positioned inward of the first cylindrical slot along a radial direction.
  • 12. The magneto-caloric thermal diode assembly of claim 11, wherein the first cylindrical slot has a width along the radial direction, the first magneto-caloric cylinder having a thickness along the radial direction within the first cylindrical slot, the width of the first cylindrical slot being about one hundredth of an inch greater than the thickness of the first magneto-caloric cylinder.
  • 13. The magneto-caloric thermal diode assembly of claim 1, wherein first and second pluralities of thermal stages each comprises no less than eight thermal stages.
  • 14. The magneto-caloric thermal diode assembly of claim 1, wherein each non-magnetic ring of the first plurality of thermal stages is in conductive thermal contact with a respective non-magnetic ring of the second plurality of thermal stages along a radial direction.
  • 15. The magneto-caloric thermal diode assembly of claim 14, wherein each non-magnetic ring of the first plurality of thermal stages is integral with the respective non-magnetic ring of the second plurality of thermal stages along the radial direction.
  • 16. The magneto-caloric thermal diode assembly of claim 14, wherein each magneto-caloric stage of the first magneto-caloric cylinder is aligned with a respective magneto-caloric stage of the second magneto-caloric cylinder along the radial direction, each magneto-caloric stage of the first magneto-caloric cylinder having a common Curie temperature with the respective magneto-caloric stage of the second magneto-caloric cylinder.
  • 17. The magneto-caloric thermal diode assembly of claim 1, wherein a cold side thermal stage of the first plurality of thermal stages is positioned at the cold side; a cold side thermal stage of the second plurality of thermal stages is positioned at the cold side;the non-magnetic ring of the cold side thermal stage of the first plurality of thermal stages is in conductive thermal contact with the non-magnetic ring of the cold side thermal stage of the second plurality of thermal stages; andother than the cold side thermal stages of the first and second pluralities of thermal stages, each non-magnetic ring of the first plurality of thermal stages is spaced from a respective non-magnetic ring of the second plurality of thermal stages along a radial direction.
  • 18. The magneto-caloric thermal diode assembly of claim 17, wherein, other than the cold side thermal stages of the first and second pluralities of thermal stages, each non-magnetic ring of the first plurality of thermal stages is spaced from the respective non-magnetic ring of the second plurality of thermal stages along the radial direction by insulation.
  • 19. The magneto-caloric thermal diode assembly of claim 17, wherein the first and second magneto-caloric cylinders each comprises a plurality of magneto-caloric stages, each magneto-caloric stage of the plurality of magneto-caloric having a different Curie temperature.
  • 20. A magneto-caloric thermal diode assembly, comprising: a first magneto-caloric cylinder;a first plurality of thermal stages stacked along an axial direction between a cold side and a hot side;a second magneto-caloric cylinder; anda second plurality of thermal stages stacked along the axial direction between the cold side and the hot side,wherein the first plurality of thermal stages and the first magneto-caloric cylinder configured for relative rotation between the first plurality of thermal stages and the first magneto-caloric cylinder,the second plurality of thermal stages and the second magneto-caloric cylinder configured for relative rotation between the second plurality of thermal stages and the second magneto-caloric cylinder,the second magneto-caloric cylinder and the second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and the first plurality of thermal stages, andeach thermal stage of the first and second pluralities of thermal stages comprises a plurality of non-magnetic blocks and a magnetic ring, the plurality of non-magnetic blocks in each of the thermal stages of the first and second pluralities of thermal stages distributed along a circumferential direction within the magnetic ring in each of the thermal stages of the first and second pluralities of thermal stages.
US Referenced Citations (261)
Number Name Date Kind
668560 Fulner et al. Feb 1901 A
1985455 Mosby Dec 1934 A
2671929 Gayler Mar 1954 A
2765633 Muffly Oct 1956 A
3618265 Croop Nov 1971 A
3816029 Bowen et al. Jun 1974 A
3956076 Powell, Jr. et al. May 1976 A
4037427 Kramer Jul 1977 A
4102655 Jeffery et al. Jul 1978 A
4107935 Steyert, Jr. Aug 1978 A
4197709 Hochstein Apr 1980 A
4200680 Sasazawa et al. Apr 1980 A
4259843 Kausch Apr 1981 A
4332135 Barclay et al. Jun 1982 A
4507927 Barclay Apr 1985 A
4507928 Johnson Apr 1985 A
4549155 Halbach Oct 1985 A
4554790 Nakagome et al. Nov 1985 A
4557228 Samodovitz Dec 1985 A
4599866 Nakagome et al. Jul 1986 A
4625519 Hakuraku et al. Dec 1986 A
4642994 Barclay et al. Feb 1987 A
4735062 Woolley et al. Apr 1988 A
4741175 Schulze May 1988 A
4785636 Hakuraku et al. Nov 1988 A
4796430 Malaker et al. Jan 1989 A
5062471 Jaeger Nov 1991 A
5091361 Hed Feb 1992 A
5156003 Yoshiro et al. Oct 1992 A
5190447 Schneider Mar 1993 A
5249424 DeGregoria et al. Oct 1993 A
5336421 Kurita et al. Aug 1994 A
5351791 Rosenzweig Oct 1994 A
5465781 DeGregoria Nov 1995 A
5599177 Hetherington Feb 1997 A
5661895 Irgens Sep 1997 A
5718570 Beckett et al. Feb 1998 A
5934078 Lawton, Jr. et al. Aug 1999 A
6332323 Reid et al. Dec 2001 B1
6423255 Hoechsmann et al. Jul 2002 B1
6446441 Dean Sep 2002 B1
6467274 Barclay et al. Oct 2002 B2
6517744 Hara et al. Feb 2003 B1
6526759 Zimm et al. Mar 2003 B2
6588215 Ghoshal Jul 2003 B1
6612816 Vanden Brande et al. Sep 2003 B1
6668560 Zimm et al. Dec 2003 B2
6826915 Wada et al. Dec 2004 B2
6840302 Tanaka et al. Jan 2005 B1
6915647 Tsuchikawa et al. Jul 2005 B2
6935121 Fang et al. Aug 2005 B2
6946941 Chell Sep 2005 B2
6971245 Kuroyanagi Dec 2005 B2
7148777 Chell et al. Dec 2006 B2
7297270 Bernard et al. Nov 2007 B2
7313926 Gurin Jan 2008 B2
7481064 Kitanovski et al. Jan 2009 B2
7552592 Iwasaki et al. Jun 2009 B2
7644588 Shin et al. Jan 2010 B2
7863789 Zepp et al. Jan 2011 B2
7897898 Muller et al. Mar 2011 B2
7938632 Smith May 2011 B2
8061147 Dinesen et al. Nov 2011 B2
8069662 Albert Dec 2011 B1
8099964 Saito et al. Jan 2012 B2
8174245 Carver May 2012 B2
8191375 Sari et al. Jun 2012 B2
8209988 Zhang et al. Jul 2012 B2
8216396 Dooley et al. Jul 2012 B2
8310325 Zhang et al. Nov 2012 B2
8375727 Sohn Feb 2013 B2
8378769 Heitzler et al. Feb 2013 B2
8448453 Bahl et al. May 2013 B2
8551210 Reppel et al. Oct 2013 B2
8596084 Herrera et al. Dec 2013 B2
8616009 Dinesen et al. Dec 2013 B2
8656725 Muller et al. Feb 2014 B2
8695354 Heitzler et al. Apr 2014 B2
8729718 Kuo et al. May 2014 B2
8763407 Carroll et al. Jul 2014 B2
8769966 Heitzler et al. Jul 2014 B2
8869541 Heitzler et al. Oct 2014 B2
8904806 Cramet et al. Dec 2014 B2
8935927 Kobayashi et al. Jan 2015 B2
8978391 Muller et al. Mar 2015 B2
9175885 Katter Nov 2015 B2
9245673 Carroll et al. Jan 2016 B2
9377221 Benedict Jun 2016 B2
9400126 Takahashi et al. Jul 2016 B2
9523519 Muller Dec 2016 B2
9534817 Benedict et al. Jan 2017 B2
9548151 Muller Jan 2017 B2
9599374 Takahashi et al. Mar 2017 B2
9631843 Benedict Apr 2017 B2
9702594 Vetrovec Jul 2017 B2
9739510 Hassen Aug 2017 B2
9797630 Benedict et al. Oct 2017 B2
9810454 Tasaki et al. Nov 2017 B2
9857105 Schroeder et al. Jan 2018 B1
9857106 Schroeder et al. Jan 2018 B1
9927155 Boeder et al. Mar 2018 B2
9978487 Katter et al. May 2018 B2
10006675 Benedict et al. Jun 2018 B2
10018385 Radermacher et al. Jul 2018 B2
20020040583 Barclay et al. Apr 2002 A1
20020066368 Zornes Jun 2002 A1
20020087120 Rogers et al. Jul 2002 A1
20030010054 Esch et al. Jan 2003 A1
20030051774 Saito Mar 2003 A1
20040093877 Wada May 2004 A1
20040182086 Chiang et al. Sep 2004 A1
20040187510 Jung Sep 2004 A1
20040187803 Regev Sep 2004 A1
20040250550 Bruck Dec 2004 A1
20050017394 Hochsmann et al. Jan 2005 A1
20050109490 Harmon et al. May 2005 A1
20050217278 Mongia et al. Oct 2005 A1
20050274676 Kumar et al. Dec 2005 A1
20060130518 Kang et al. Jun 2006 A1
20060231163 Hirosawa et al. Oct 2006 A1
20070130960 Muller et al. Jun 2007 A1
20070220901 Kobayashi Sep 2007 A1
20080223853 Muller et al. Sep 2008 A1
20080236171 Saito et al. Oct 2008 A1
20080236175 Chaparro Monferrer et al. Oct 2008 A1
20080303375 Carver Dec 2008 A1
20090091411 Zhang et al. Apr 2009 A1
20090158749 Sandeman Jun 2009 A1
20090217674 Kaji et al. Sep 2009 A1
20090236930 Nashiki Sep 2009 A1
20090266083 Shin et al. Oct 2009 A1
20090308080 Han et al. Dec 2009 A1
20090314860 Wang et al. Dec 2009 A1
20090320499 Muller et al. Dec 2009 A1
20100000228 Wiest et al. Jan 2010 A1
20100058775 Kaji et al. Mar 2010 A1
20100071383 Zhang et al. Mar 2010 A1
20100116471 Reppel May 2010 A1
20100122488 Fukai May 2010 A1
20100150747 Mehta et al. Jun 2010 A1
20100162747 Hamel et al. Jul 2010 A1
20100209084 Nelson et al. Aug 2010 A1
20100236258 Heitzler et al. Sep 2010 A1
20100276627 Mazet Nov 2010 A1
20100303917 Watson et al. Dec 2010 A1
20110000206 Aprad Jan 2011 A1
20110042608 Reesink Feb 2011 A1
20110048031 Barve Mar 2011 A1
20110048690 Reppel et al. Mar 2011 A1
20110058795 Kleman et al. Mar 2011 A1
20110061398 Shih et al. Mar 2011 A1
20110062821 Chang et al. Mar 2011 A1
20110082026 Sakatani et al. Apr 2011 A1
20110094243 Carroll et al. Apr 2011 A1
20110129363 Sakai et al. Jun 2011 A1
20110154832 Barve et al. Jun 2011 A1
20110162388 Barve et al. Jul 2011 A1
20110168363 Reppel et al. Jul 2011 A9
20110173993 Muller et al. Jul 2011 A1
20110182086 Mienko et al. Jul 2011 A1
20110192836 Muller et al. Aug 2011 A1
20110218921 Addala et al. Sep 2011 A1
20110239662 Bahl et al. Oct 2011 A1
20110284196 Zanadi Nov 2011 A1
20110302931 Sohn Dec 2011 A1
20110308258 Smith et al. Dec 2011 A1
20110314836 Heitzler et al. Dec 2011 A1
20120031108 Kobayashi et al. Feb 2012 A1
20120033002 Seeler et al. Feb 2012 A1
20120036868 Heitzler et al. Feb 2012 A1
20120045698 Shima Feb 2012 A1
20120060526 May et al. Mar 2012 A1
20120079834 Dinesen Apr 2012 A1
20120222427 Hassen Sep 2012 A1
20120222428 Celik et al. Sep 2012 A1
20120266591 Morimoto et al. Oct 2012 A1
20120266607 Morimoto et al. Oct 2012 A1
20120267090 Kruglick Oct 2012 A1
20120272665 Watanabe et al. Nov 2012 A1
20120272666 Watanabe Nov 2012 A1
20120285179 Morimoto Nov 2012 A1
20120291453 Watanabe et al. Nov 2012 A1
20130019610 Zimm et al. Jan 2013 A1
20130020529 Chang et al. Jan 2013 A1
20130104568 Kuo et al. May 2013 A1
20130106116 Kuo et al. May 2013 A1
20130145573 Bizhanzadeh Jun 2013 A1
20130180263 Choi et al. Jul 2013 A1
20130186107 Shih et al. Jul 2013 A1
20130187077 Katter Jul 2013 A1
20130192269 Wang Aug 2013 A1
20130199460 Duplessis et al. Aug 2013 A1
20130227965 Yagi et al. Sep 2013 A1
20130232993 Saito et al. Sep 2013 A1
20130255279 Tomimatsu et al. Oct 2013 A1
20130269367 Meillan Oct 2013 A1
20130298571 Morimoto et al. Nov 2013 A1
20130300243 Gieras et al. Nov 2013 A1
20130319012 Kuo et al. Dec 2013 A1
20130327062 Watanabe et al. Dec 2013 A1
20140020881 Reppel et al. Jan 2014 A1
20140075958 Takahashi et al. Mar 2014 A1
20140116538 Tanaka et al. May 2014 A1
20140157793 Johnson et al. Jun 2014 A1
20140165594 Benedict Jun 2014 A1
20140165595 Zimm et al. Jun 2014 A1
20140190182 Benedict Jul 2014 A1
20140216057 Oezcan Aug 2014 A1
20140260373 Gerber et al. Sep 2014 A1
20140290273 Benedict et al. Oct 2014 A1
20140290275 Muller Oct 2014 A1
20140291570 Klausner et al. Oct 2014 A1
20140305137 Benedict Oct 2014 A1
20140305139 Takahashi et al. Oct 2014 A1
20140311165 Watanabe et al. Oct 2014 A1
20140325996 Muller Nov 2014 A1
20140366557 Mun et al. Dec 2014 A1
20150007582 Kim et al. Jan 2015 A1
20150027133 Benedict Jan 2015 A1
20150030483 Ryu Jan 2015 A1
20150033762 Cheng et al. Feb 2015 A1
20150033763 Saito et al. Feb 2015 A1
20150047371 Hu et al. Feb 2015 A1
20150068219 Komorowski et al. Mar 2015 A1
20150089960 Takahashi Apr 2015 A1
20150096307 Watanabe et al. Apr 2015 A1
20150114007 Neilson et al. Apr 2015 A1
20150168030 Leonard et al. Jun 2015 A1
20150211440 Joffroy Jul 2015 A1
20150260433 Choi et al. Sep 2015 A1
20150267943 Kim et al. Sep 2015 A1
20150362224 Benedict et al. Dec 2015 A1
20150362225 Schwartz Dec 2015 A1
20150369524 Ikegami et al. Dec 2015 A1
20160000999 Focht et al. Jan 2016 A1
20160025385 Auringer et al. Jan 2016 A1
20160032920 Hatami Aghdam Feb 2016 A1
20160084544 Radermacher et al. Mar 2016 A1
20160091227 Leonard et al. Mar 2016 A1
20160146515 Momen et al. May 2016 A1
20160216012 Benedict et al. Jul 2016 A1
20160238287 Benedict Aug 2016 A1
20160273811 Smith et al. Sep 2016 A1
20160282021 Zhao et al. Sep 2016 A1
20160298880 Humburg Oct 2016 A1
20160355898 Vieym Villegas et al. Dec 2016 A1
20160356529 Humburg Dec 2016 A1
20160367982 Pennie Dec 2016 A1
20170059213 Barclay et al. Mar 2017 A1
20170071234 Garg Mar 2017 A1
20170138648 Cui May 2017 A1
20170176083 Sul et al. Jun 2017 A1
20170309380 Benedict et al. Oct 2017 A1
20170328603 Barclay et al. Nov 2017 A1
20170328649 Brandmeier Nov 2017 A1
20170370624 Zimm et al. Dec 2017 A1
20180005735 Scharf et al. Jan 2018 A1
20180023852 Schroeder et al. Jan 2018 A1
20180195775 Schroeder et al. Jul 2018 A1
20180283740 Holladay et al. Oct 2018 A1
20180340715 Benedict et al. Nov 2018 A1
Foreign Referenced Citations (57)
Number Date Country
2893874 Jun 2014 CA
2919117 Jan 2015 CA
101280983 Oct 2008 CN
101979937 Feb 2011 CN
201772566 Mar 2011 CN
101788207 Sep 2011 CN
202432596 Sep 2012 CN
103090583 May 2013 CN
103712401 Apr 2014 CN
102077303 Apr 2015 CN
106481842 Mar 2017 CN
102013223959 May 2015 DE
202015106851 Mar 2016 DE
0187078 Jul 1986 EP
2071255 Jun 2009 EP
2108904 Oct 2009 EP
2215955 Aug 2010 EP
2322072 May 2011 EP
2420760 Feb 2012 EP
3306082 Apr 2018 EP
2935468 Mar 2010 FR
59232922 Dec 1984 JP
H08166182 Jun 1996 JP
3205196 Sep 2001 JP
2002315243 Oct 2002 JP
2007147136 Jun 2007 JP
2007291437 Nov 2007 JP
2008051412 Mar 2008 JP
2010112606 May 2010 JP
201052591 Jul 2010 JP
6212955 Dec 2014 JP
2014228216 Dec 2014 JP
5907023 Apr 2016 JP
6079498 Feb 2017 JP
6191539 Sep 2017 JP
2017207222 Nov 2017 JP
101100301 Dec 2011 KR
101238234 Mar 2013 KR
WO0133145 May 2001 WO
WO0212800 Feb 2002 WO
WO03016794 Feb 2003 WO
WO-03016794 Feb 2003 WO
WO2004068512 Aug 2004 WO
WO2007036729 Apr 2007 WO
WO2007086638 Aug 2007 WO
WO2009024412 Feb 2009 WO
WO2009098391 Aug 2009 WO
WO2010119591 Oct 2010 WO
WO2011034594 Mar 2011 WO
WO2014099199 Jun 2014 WO
WO2014170447 Oct 2014 WO
WO2014173787 Oct 2014 WO
WO2015017230 Feb 2015 WO
WO2016035267 Mar 2016 WO
WO2017042266 Mar 2017 WO
WO2017081048 May 2017 WO
WO2017097989 Jun 2017 WO
Non-Patent Literature Citations (13)
Entry
Stefano Dall'Olio, et al., Numerical Simulation of a Tapered Bed AMR, Technical University of Denmark, 2015, 2 pages.
C Aprea, et al., An innovative rotary permanent magnet magnetic refrigerator based on AMR cycle, Thermal Energy Systems: Production, Storage, Utilization and the Environment, dated May 2015, Napoli, Italy, pp. 1-5.
International Search Report issued in connection with PCT Application No. PCT/US2014/042485 dated Oct. 23, 2014.
International Search Report issued in connection with PCT Application No. PCT/US2014/017431 dated May 9, 2014.
International search report issued in connection with PCT/US2013/070518, dated Jan. 22, 2014.
Tetsuji Okamura, Performance of a room-temperature rotary magnet refrigerator, dated Nov. 28, 2005, Elsevier.
Journal of Alloys and Compounds, copyright 2008 Elsevier B..V.
Evaluation of Ni—Mn—In—Si Alloys for Magnetic Refrigerant Application, Rahul Das, A. Perumal and A. Srinivasan, Dept of Physics, Indian Institute of Technology, Oct. 10, 2011.
Effects of annealing on the magnetic entropy change and exchange bias behavior in melt-spun Ni—Mn—In ribbons, X.Z. Zhao, C.C. Hsieh, et al Science Direct, Scripta Materialia 63 (2010).
PCT International Search Report and Written Opinion issued in connection with PCT Application No. PCT/US2013/070023 dated Feb. 27, 2014.
Barbara Pulko, Epoxy-bonded La—Fe—Co—Si magnetocaloric plates, Journal of Magnetism and Magnetic Materials, 375 (2015) 65-73.
International Search Report of PCT/US2014/047925 dated Nov. 10, 2014.
Andrej Kitanovski, Present and future caloric refrigeration and heat-pump technologies, International Journal of Refrigeration, vol. 57 Sep. 2015, pp. 288-298.
Related Publications (1)
Number Date Country
20190323740 A1 Oct 2019 US