1. A magnetic cooling device is provided with the following magnetic cooling device in a hollow container:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material separating part between the material filling part and the gas storage part,

in the magnetic cooling device described above, it is preferable that,

the volume fraction of the inert gas in the hollow container is 1 vol% or more and 12 vol% or less.

2. The magnetic cooling apparatus according to claim 1, wherein the magnetic material has a particle diameter of 100 μm or more and 3000 μm or less.

3. The magnetic cooling device according to claim 1 or 2, wherein the magnetic material particles are selected from Gd_1－aM_aAnd (La)_{1－ b}Re_b)(Fe_1－c－dTM_cSi_d)₁₃H_eAt least one selected from the group consisting of,

the Gd_1－aM_aWherein M is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Er, a is 0. ltoreq. a.ltoreq.0.5,

the (La) is_1－bRe_b)(Fe_1－c－dTM_cSi_d)₁₃H_eWherein Re is at least one selected from the group consisting of Ce, Pr, Nd, Pm, Sm and GdTM is at least one transition metal element selected from the group consisting of V, Cr, Mn, Co, Ni, Cu and Zn, b, c, d and e are respectively 0-0 b-0.2, 0-0 c-0.04, 0.09-d-0.13 and 0-0 e-1.5. .

4. The magnetic cooling device of claim 3, wherein the magnetic material is composed of the formula Gd_1－aY_aThe alloy represented by (1), wherein a is 0. ltoreq. a.ltoreq.0.05.

5. The magnetic cooling device according to any one of claims 1 to 4, wherein the oxygen content of the inert gas is 10 vol% or less.

6. The magnetic cooling device according to any one of claims 1 to 5, wherein the inert gas is selected from the group consisting of nitrogen gas, argon gas, or a mixed gas of nitrogen and argon.

7. The magnetic cooling apparatus according to any one of claims 1 to 6, wherein a volume fraction of the inert gas in the hollow container is 6 vol% or more and 10 vol% or less.

8. The magnetic cooling device according to any one of claims 1 to 7, wherein the material partition is a mesh structure having a mesh size smaller than a particle diameter of the magnetic material.

9. The magnetic cooling device according to any one of claims 1 to 8, wherein a volume fraction of the gas storage portion in the hollow container is 10 vol% or more and 50 vol% or less.

10. A magnetic cooling device comprising the magnetic cooling apparatus according to any one of claims 1 to 9.

11. A magnetic cooling method using a magnetic cooling device provided with a magnetic cooling means having the following configuration in a hollow container:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material separating part between the material filling part and the gas storage part,

in the magnetic cooling method,

the particle diameter d of the magnetic material is more than 100 μm and less than 3000 μm,

the flow velocity v of the refrigerant in the magnetic cooling cycle is 20mm/s or more and 80mm/s or less,

the volume fraction x of the inert gas in the hollow container is 1 vol% or more and 12 vol% or less,

and satisfies the following formula (1)

x≤2.1v²And 1. ltoreq. x.ltoreq.12 (1).

Background

At present, a gas cooling system is mainly used as a cooling method, but according to the montreal protocol based on the correction of gali in 2016, freon gas and alternative freon gas used as a refrigerant of the gas cooling system are regulated intensively to promote global warming. Therefore, a magnetic cooling system has been proposed which does not use freon gas or substitute for freon gas.

In the magnetic cooling method, it is necessary to change the magnetic order of the magnetic material by the magnetic field in an adiabatic state by utilizing the magnetocaloric effect in which the magnetic material generates heat when the magnetic field is applied to the magnetic material, and to exchange heat between the thermal energy accompanying the change of the magnetic entropy at that time and the refrigerant. Therefore, the magnetic cooling device used in the magnetic cooling method performs cooling by a continuously repeated magnetic cooling cycle as follows: in a hollow container such as a cylindrical container, a magnetic body having a magnetocaloric effect is filled in a shape allowing a refrigerant to flow inside the hollow container, and the magnetic cooling device configured as above alternately and continuously repeats application and unloading of a magnetic field and conveyance of the refrigerant. In the magnetic cooling device, a magnetic material as a solid refrigerant and a refrigerant such as water for exchanging heat with the magnetic material are used as the refrigerant, and there is no need to replace an environmental load substance such as freon gas. Further, as the gas cooling system, a series of cooling cycles undergoes a process with large irreversibility, and therefore the actual cooling efficiency is lower than the theoretical efficiency, while as the magnetic cooling system, a process with large irreversibility is not required, and therefore attention is drawn from the viewpoint of improving the cooling capacity and efficiency.

As a conventional disclosure for achieving high cooling efficiency in the magnetic cooling system, there is a magnetic cooling device as shown in patent document 1. Patent document 1 discloses a method of reducing the input electric power of a magnetic cooling device by mechanically connecting a magnetic modulation device and a refrigerant delivery device constituting the magnetic cooling device to reduce the number of power sources, thereby improving the cooling efficiency, which is the ratio of the cooling output power to the input electric power.

Prior art documents

Patent document

Patent document 1: japanese laid-open patent publication No. 2010-151407

Disclosure of Invention

A magnetic cooling device according to an aspect of the present invention is a magnetic cooling device including a hollow container, the hollow container including:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material separating part between the material filling part and the gas storage part,

in the magnetic cooling device described above, it is preferable that,

the volume fraction of the inert gas in the hollow container is 1 vol% or more and 12 vol% or less.

A magnetic cooling method according to an aspect of the present invention is a magnetic cooling method using a magnetic cooling device including a magnetic cooling device having:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material separating part between the material filling part and the gas storage part,

in the magnetic cooling method,

the magnetic material has a particle diameter d (μm) of 100 to 3000 μm,

a flow velocity v (mm/s) of the refrigerant in the magnetic cooling cycle is 20mm/s or more and 80mm/s or less,

the volume fraction x (vol%) of the inert gas in the hollow container is 1 vol% or more and 12 vol% or less,

and satisfies the following formula (1).

x≤2.1v²D, and x is more than or equal to 1 and less than or equal to 12 (1)

Drawings

Fig. 1 is a schematic structural sectional view of a magnetic cooling device of an embodiment of the present invention.

Fig. 2 is a schematic structural sectional view of a magnetic cooling device according to an embodiment of the present invention.

Fig. 3A is a diagram illustrating a cooling operation procedure of the magnetic cooling device according to the embodiment of the present invention.

Fig. 3B is a diagram illustrating a cooling operation procedure of the magnetic cooling device according to the embodiment of the present invention.

Fig. 3C is a diagram illustrating a cooling operation procedure of the magnetic cooling device according to the embodiment of the present invention.

Fig. 3D is a diagram illustrating a cooling operation procedure of the magnetic cooling device according to the embodiment of the present invention.

Description of the symbols

101 magnetic cooling device

102 hollow container

103 material filling part

104 material partition

105 gas storage part

106 particles of magnetic material

107 refrigerant

108 first non-reactive gas

109 refrigerant conveying device

110 second inert gas

111 magnetic cooling device

112 inert gas introduction part

113 low temperature heat exchanger

114 high-temperature heat exchanger

115 magnetic field modulation device

Detailed Description

The present inventors have recognized that problems to be overcome still exist in conventional magnetic cooling apparatuses, and have found that measures are necessary. Specifically, the following problems have been found.

In the magnetic cooling device having the above configuration, since there is a wake region, that is, a region where momentum exchange of the refrigerant proceeds inactively in the gaps of the filled magnetic material particles, the heat exchange property between the magnetic material particles and the refrigerant is low. Therefore, in the magnetic cooling device, since a temperature difference is formed by heat exchange between the heat release/absorption amount of the magnetic material and the refrigerant, there is a problem that the cooling capacity is small if the heat exchange property between the magnetic material particles and the refrigerant is low.

The present invention has been made in view of the improvement of cooling capacity of a magnetic cooling device used for a magnetic cooling apparatus, and an object thereof is to provide a novel magnetic cooling device in which heat exchange between magnetic material particles and a refrigerant is improved and cooling capacity due to magnetocaloric effect is improved.

One embodiment of the present invention for solving the above problems is as follows.

[ item 1]

A magnetic cooling device is provided with the following magnetic cooling device in a hollow container:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material partition between the material filling part and the gas storage part, the volume fraction of the inert gas in the hollow container being as follows in the magnetic cooling apparatus

1 vol% or more and 12 vol% or less.

[ item 2]

The magnetic cooling apparatus according to item 1, wherein the magnetic material has a particle diameter of 100 μm or more and 3000 μm or less.

[ item 3]

The magnetic cooling apparatus of item 1 or 2, wherein the magnetic material particles are selected from Gd_1－aM_a[ wherein M is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Er, and a is 0. ltoreq. a.ltoreq.0.5](ii) a And (La)_1－bRe_b)(Fe_1－c－dTM_cSi_d)₁₃H_e[ wherein Re is at least one rare earth element selected from the group consisting of Ce, Pr, Nd, Pm, Sm and Gd, TM is at least one transition metal element selected from the group consisting of V, Cr, Mn, Co, Ni, Cu and Zn, b, c, d and e are respectively 0. ltoreq. b.ltoreq.0.2, 0. ltoreq. c.ltoreq.0.04, 0.09. ltoreq. d.ltoreq.0.13, 0. ltoreq. e.ltoreq.1.5]At least one selected from the group consisting of.

[ item 4]

The magnetic cooling apparatus of item 3 wherein the magnetic material is of the compositional formula Gd_1－aY_a(0. ltoreq. a. ltoreq.0.05).

[ item 5]

The magnetic cooling apparatus according to any one of items 1 to 4, wherein the oxygen content of the inert gas is 10 vol% or less.

[ item 6]

The magnetic cooling apparatus according to any one of items 1 to 5, wherein the inert gas is selected from a group consisting of nitrogen gas, argon gas, or a mixed gas of nitrogen and argon.

[ item 7]

The magnetic cooling apparatus according to any one of items 1 to 6, wherein a volume fraction of the inert gas in the hollow container is 6 vol% or more and 10 vol% or less.

[ item 8]

The magnetic cooling device according to any one of items 1 to 7, wherein the mesh of the material partition part has a mesh structure having a size smaller than a particle diameter of the magnetic material.

[ item 9]

The magnetic cooling device according to any one of items 1 to 8, wherein a volume fraction of the gas storage portion in the hollow container is 10 vol% or more and 50 vol% or less.

[ item 10]

A magnetic cooling device comprising the magnetic cooling apparatus according to any one of items 1 to 9.

[ item 11]

A magnetic cooling method using a magnetic cooling device provided with a magnetic cooling means having the following configuration in a hollow container:

a material filling part containing an inactive gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

a gas storage part at both ends of the material filling part and containing the refrigerant; and

a material separating part between the material filling part and the gas storage part,

in the magnetic cooling method,

the magnetic material has a particle diameter d (μm) of 100 to 3000 μm,

a flow velocity v (mm/s) of the refrigerant in the magnetic cooling cycle is 20mm/s or more and 80mm/s or less,

the volume fraction x (vol%) of the inert gas in the hollow container is 1 vol% or more and 12 vol% or less,

and satisfies the following formula (1).

x≤2.1v²D, and x is more than or equal to 1 and less than or equal to 12 (1)

According to the magnetic cooling device of the present invention, the heat exchange property between the magnetic material particles and the refrigerant is improved, and therefore, a magnetic cooling device having high cooling capability based on the magnetocaloric effect can be provided.

Hereinafter, a magnetic cooling apparatus according to an embodiment of the present invention will be described in more detail with reference to the drawings as necessary. However, unnecessary detailed description may be omitted. For example, a detailed description of already known matters may be omitted, or a repetitive description of substantially the same configuration may be omitted. This is to avoid the description becoming unnecessarily lengthy and easy for the practitioner to understand. The applicant provides the drawings and the following description in order for the practitioner to understand the present invention sufficiently, and intends not to limit the main stream described herein. Various elements in the drawings are schematically and exemplarily shown for understanding the present invention, and the appearance, the size ratio, and the like may be different from those of the actual objects.

< magnetic cooling apparatus 101 >

The magnetic cooling device 101 of the present invention is a device that can be used for cooling (e.g., refrigeration) utilizing the magnetocaloric effect.

The magnetic cooling apparatus 101 of the present invention is configured such that a hollow container 102 has:

a material filling unit 103 containing an inert gas, magnetic material particles having a magnetocaloric effect, and a refrigerant;

gas storage portions 105 containing the refrigerant at both ends of the material filling portion; and

a material separating part 104 between the material filling part and the gas storage part.

Fig. 1 shows a schematic structural section of a magnetic cooling device 101 according to the invention. The magnetic cooling apparatus 101 of the present invention may include, inside the hollow container 102: the central intermediate material filling portion 103 has material partitioning portions 104 at both ends in the longitudinal direction thereof (i.e., the direction in which heat moves (the direction in which refrigerant flows)), and gas storage portions 105 at the outer sides of both ends thereof. The inert gas is present in at least one of the material filling portion 103 and the gas storage portion 105, and the inert gas located in the gaps between the magnetic material particles 106 in the material filling portion 103 is referred to as a first inert gas 108, and the inert gas located in the gas storage portion 105 is referred to as a second inert gas. Details of each configuration will be described with reference to the drawings.

[ hollow vessel 102]

The shape of the hollow container 102 is not particularly limited, but a cylindrical container having a circular or polygonal cross section is generally used. Examples of the material of the hollow container 102 are not particularly limited, but may be selected from the viewpoint of thermal conductivity, magnetic permeability, and the like of the material, and may be resin, metal, ceramic, glass, a combination thereof, and the like.

[ Material-filled portion 103]

The material filling portion 103 is filled with magnetic material particles 106, and the gap thereof is composed of a refrigerant 107 and a first inert gas 108.

The material filling part 103 may be 30 vol% or more, 40 vol% or more, 50 vol% or more, 55 vol% or more, 60 vol% or more, or 65 vol% or more, preferably 50 vol% or more, of the hollow vessel 102. The material filling portion 103 may be 95 vol% or less, 90 vol% or less, 5 vol% or less, 80 vol% or less, 75 vol% or less, or 70 vol% or less, and preferably 85 vol% or less.

[ Material partitioning portion 104]

The material separator 104 may be configured to allow the refrigerant 107 to pass therethrough, and may have a structure in which the mesh size is smaller than that of the magnetic material particles 106, or a structure in which the magnetic material particles 106 do not pass therethrough. The material partition 104 is provided between the material filling portion 103 and the air storage portion 105. The material partition 104 may be made of a mesh of stainless steel, resin, or the like. When the magnetic material particles 106 are integrated with a resin binder or the like, they may be replaced with c-rings or o-rings. With the material partition 104, the refrigerant 107 in the gas storage portion 105 can be caused to pass through the material filling portion 103 in a state where the material filling portion 103 is fixed inside the hollow container 102.

[ gas storage part 105]

The gas reservoir 105 is composed of a second inert gas 110 and a refrigerant 107, and nitrogen gas and argon gas, or a mixed gas of nitrogen and argon, or the like can be used as the second inert gas 110. Similarly to the first inert gas 108, in the magnetic cooling cycle, the second inert gas 110 foams the refrigerant 107, thereby reducing the concentration of dissolved oxygen in the refrigerant 107 and reducing deterioration such as corrosion of the magnetic material particles 106.

The gas reservoir 105 (total of the gas reservoir 105 on the low temperature side and the gas reservoir on the high temperature side) may be 5 vol% or more, 10 vol% or more, 15 vol% or more, or 25 vol% or more, preferably 10 vol% or more of the hollow vessel 102. The gas storage portion 105 may be 70 vol% or less, 60 vol% or less, 50 vol% or less, or 40 vol% or less, preferably 50 vol% or less of the hollow container 102. In the present specification, "to vol% of hollow container 102" means a volume ratio to the internal volume of hollow container 102. The volume ratio of the low-temperature-side gas reservoir 105 to the high-temperature-side gas reservoir may be, for example, 0.2/0.8 to 0.8/0.2 or 0.3/0.7 to 0.7/0.3.

In the magnetic cooling cycle, the second inert gas 110 is supplied to the material filling portion 103 to replenish the shortage of the first inert gas 108 that is lost from the material filling portion 103 to the gas storage portion 105. Since the gas storage part 105 needs to continuously supply the inactive gas into the material filling part 103 during the magnetic cooling cycle, it is preferable that the gas storage part 105 has a shape (e.g., a valve structure, a cover structure, etc.) capable of preventing the second inactive gas 110 from flowing out to the outside of the magnetic cooling apparatus 101.

[ magnetic material particles 106]

As the magnetic material particles 106, particles made of a known magnetocaloric material can be used, and can be appropriately selected depending on the ambient temperature in the magnetic cooling cycle, the cooling capacity to be achieved, and the like. Examples of the magnetocaloric material include Gd_{1－ a}M_a[ wherein M is at least one element selected from the group consisting of Y, La, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho and Er (for example, M isY), 0. ltoreq. a.ltoreq.0.5 (e.g., 0. ltoreq. a.ltoreq.0.1, and 0. ltoreq. a.ltoreq.0.05, etc.)]And the like Gd-based magnetocaloric materials; (La)_{1－ b}Re_b)(Fe_1－c－dTM_cSi_d)₁₃H_e[ wherein Re is at least one rare earth element selected from the group consisting of Ce, Pr, Nd, Pm, Sm and Gd, TM is at least one transition metal element selected from the group consisting of V, Cr, Mn, Co, Ni, Cu and Zn, b, c, d and e are La (FeSi) such as 0. ltoreq. b.ltoreq.0.2, 0. ltoreq. c.ltoreq.0.04, 0.09. ltoreq. d.ltoreq.0.13, 0. ltoreq. e.ltoreq.1.5, etc₁₃A magnetocaloric material, etc.

The particle diameter d of the magnetic material particles 106 may be 100 μm or more, 200 μm or more, 300 μm or more, 400 μm or more, or 500 μm or more, and preferably 300 μm or more. The particle diameter d of the magnetic material particles 106 may be 3000 μm or less, 2500 μm or less, 2000 μm or less, 1500 μm or less, or 1000 μm or less, preferably 2000 μm or less. When the particle diameter d is 100 μm or more, the pressure loss when the refrigerant 107 is transported is reduced, and therefore, the power consumption for transporting the refrigerant 107 can be reduced. On the other hand, when the particle diameter d is less than 3000 μm, the surface area of the magnetic material particles 106 in contact with the refrigerant 107 becomes large, and therefore the heat exchange property between the magnetic material particles 106 and the refrigerant 107 is remarkably improved. The "particle diameter" means a value of d50 in volume-based particle size distribution measurement that can be measured using a laser diffraction/scattering particle distribution measuring apparatus.

The filling ratio of the magnetic material particles 106 in the material filling portion 103 may be 40 vol% or more, 45 vol% or more, 50 vol% or more, 55 vol% or more, or 60 vol% or more, preferably 50 vol% or more, of the material filling portion 103. The filling rate of the magnetic material particles 106 in the material filling portion 103 may be 90 vol% or less, 85 vol% or less, 80 vol% or less, 75 vol% or less, or 70 vol% or less, preferably 80 vol% or less, of the material filling portion 103. If the volume% is 40% or more, the cooling capacity of the magnetic material particles 106 by the magnetocaloric effect can be improved, and if the volume% is 90% or less, the pressure loss at the time of transporting the refrigerant 107 can be reduced, and the power consumption for transporting the refrigerant 107 can be reduced.

When the magnetic cooling cycle is performed, the material filling portion 103 generates a temperature gradient along the longitudinal direction of the magnetic cooling device 101. Therefore, it is preferable that the material filling portion 103 has a plurality of magnetic material particles 106 exhibiting a high magnetocaloric effect in each temperature region at the time of forming the temperature gradient, in the longitudinal direction of the material filling portion 103.

[ refrigerant 107]

The refrigerant 107 is located in the gaps between the magnetic material particles 106 in the material filling portion 103 or in the gas storage portion 105. As the refrigerant 107, a known refrigerant such as pure water, alcohol (methanol, ethanol, ethylene glycol, glycerin, propanol, etc.), or an alcohol aqueous solution can be used. In order to realize a stable magnetic cooling cycle, it is preferable to use a refrigerant having a boiling point and a freezing point outside the temperature range reached by the magnetic cooling device.

[ inert gas ]

The magnetic cooling device has an inactive gas. The inert gas is a gas having low chemical reactivity with the magnetic material particles. It means that the inert gas has an oxygen content of 10 vol% or less, 8 vol% or less, 5 vol% or less, 2.5 vol% or less, or 1 vol% or less, preferably 2.5 vol% or less. The inert gas may also contain substantially no oxygen. The inert gas may be nitrogen, argon, a mixture of nitrogen and argon, or the like. The use of the inert gas can improve the heat exchange property between the magnetic material particles 106 and the refrigerant 107, which is an effect of the present invention. In addition, in the magnetic cooling cycle, the inert gas foams the refrigerant 107, thereby reducing the concentration of dissolved oxygen in the refrigerant 107 and reducing deterioration such as corrosion of the magnetic material particles 106.

The first inert gas 108 is an inert gas located in the gaps between the magnetic material particles 106 in the material filling portion 103. The second inert gas 110 is an inert gas located in the gas storage portion 105.

The volume fraction of the inert gas in the hollow vessel 102 may be 1 vol% or more, 2 vol% or more, 3 vol% or more, 5 vol% or more, 6 vol% or more, 7 vol% or more, or 8 vol% or more, preferably 6 vol% or more. The volume fraction of the inert gas in the hollow vessel 102 may be 12 vol% or less, 10 vol% or less, 9 vol% or less, or 8 vol% or less, and preferably 10 vol% or less.

< magnetic cooling device 111 >

In order to evaluate the cooling capacity of the magnetic cooling apparatus 101 of the present invention, a magnetic cooling device 111 was produced. Fig. 2 is a schematic structural sectional view of the magnetic cooling device 111. The magnetic cooling device 111 is centered on the magnetic cooling apparatus 101 of the present invention, and has an inert gas introduction part 112 connected to both ends in the longitudinal direction of the hollow container via a pipe, a low-temperature heat exchanger 113 connected to one of the outer sides thereof, a high-temperature heat exchanger 114 connected to the other end thereof, and a refrigerant transport device 109 provided between the low-temperature heat exchanger 113 and the high-temperature heat exchanger 114 to form a closed circuit for a refrigerant. Further, outside the closed refrigerant circuit, a magnetic field modulation device 115 for applying a magnetic field to the magnetic cooling apparatus is provided adjacent to the magnetic cooling apparatus.

[ refrigerant conveying device 109]

The refrigerant transport device 109 is constituted by, for example, a piston pump and a rotary pump. The refrigerant transport device 109 is preferably controlled in accordance with the operation of a magnetic field modulation device 115 described later. When the inert gas is introduced into the magnetic cooling device 101, the responsiveness of actual refrigerant conveyance corresponding to the operation of the refrigerant conveyance device 109 changes compared to the case where the inert gas is not present inside the magnetic cooling device 101 due to the difference in compressibility between liquid and gas. Since the heat transport amount of heat and cold generated by entropy change of the magnetic material particles 106 is influenced by the operation timing of the magnetic field modulation device 115 and the actual refrigerant transport, it is necessary to appropriately correct the operation timing of the magnetic field modulation device 115 and the refrigerant transport device 109 in accordance with the inert gas introduction amount in order to improve the cooling capacity.

[ inert gas introducing part 112]

The inert gas introduction part 112 is constituted by, for example, a three-way valve, and may be provided at both ends in the longitudinal direction of the hollow container of the magnetic cooling apparatus 101. The amount of inert gas in the magnetic cooling apparatus 101 can be controlled by introducing the inert gas from the inert gas introduction portion 112 into the magnetic cooling apparatus 101 after the refrigerant 107 is filled in the closed refrigerant circuit connected to the magnetic cooling apparatus 101.

[ Heat exchanger 113 for Low temperature and Heat exchanger 114 for high temperature ]

As the low-temperature heat exchanger 113 and the high-temperature heat exchanger 114, various heat exchangers such as a tube heat exchanger (multitubular or single-tube type) heat exchanger, a plate heat exchanger, a fin-tube heat exchanger, a spiral heat exchanger, a coil heat exchanger, a condensing heat exchanger, and an air-cooled heat exchanger can be used.

[ magnetic field modulation device 115]

The magnetic field modulation device 115 is constituted by a magnetic circuit incorporating a permanent magnet, and the relative position of the magnetic circuit and the magnetic cooling equipment 101 is controlled so as to be periodically changed. The magnetic field modulation device 115 is connected to an electric cylinder or the like and performs a periodic motion, thereby changing the relative position with respect to the magnetic cooling device 101. The periodic motion may be continuously operated, and the frequency thereof may be 0.01Hz or more, 0.1Hz or more, or 0.3Hz or more, and may be 10Hz or less, 5Hz or less, or 1Hz or less.

The entropy change of the magnetocaloric effect depends on the magnitude of the magnetic field, and therefore, it is desirable that the magnetic field modulation device 115 be capable of applying a strong magnetic field to the magnetic cooling apparatus 101. The magnetic field modulation device 115 can vary the intensity of the magnetic field applied to the magnetic cooling apparatus 101, for example, between 0T and 5T, between 0T and 3T, or between 0T and 1T.

< magnetic Cooling method >

The steps of magnetic cooling using the magnetic cooling device 111 including the magnetic cooling apparatus 101 are explained. Fig. 3A to D are explanatory diagrams of the operation steps of the magnetic cooling device 111.

[ step 1: exothermic reaction of the magnetic material particles 106]

By bringing the magnetic circuit of the magnetic field modulation device 115 close to the side surface of the hollow container of the magnetic cooling apparatus 101, a magnetic field is applied to the magnetic cooling apparatus, and the magnetic material particles 106 in the material filling portion 103 generate heat. (FIG. 3A)

[ step 2: heat transfer to high-temperature side Heat exchanger

By operating the refrigerant transport device 109, the refrigerant 107 in the magnetic cooling apparatus 101 is output from the low-temperature heat exchanger 113 side to the high-temperature heat exchanger 114 side. Heat is exchanged between the magnetic material particles 106 and the refrigerant 107, and the refrigerant 107 is transported in a state of accumulating heat, and therefore, heat is transported to the high-temperature heat exchanger 114. (FIG. 3B)

[ step 3: cooling reaction of magnetic particles 106]

The magnetic field applied to the magnetic cooling device is removed by making the magnetic circuit of the magnetic field modulation device 115 close to the side of the hollow vessel of the magnetic cooling device 101 far from the side of the hollow vessel of the magnetic cooling device 101, whereby the magnetic material particles 106 in the material-filled portion 103 are cooled. (FIG. 3C)

[ step 4: cold transfer to Heat exchanger for Low temperature ]

By the refrigerant transporting device 109 transporting the refrigerant 107 from the high-temperature heat exchanger 114 side to the low-temperature heat exchanger 113 side, heat is exchanged between the magnetic material particles 106 and the refrigerant 107, and the refrigerant 107 is transported in a cold storage state, and therefore, the cold is transported to the low-temperature heat exchanger 113. (FIG. 3D)

By repeating the operations of step 1 to step 4, a temperature difference is formed between the low-temperature heat exchanger 113 and the high-temperature heat exchanger 114 while forming a temperature gradient in the longitudinal direction of the material filling portion 103. The cooling capacity of the magnetic cooling device 111 can be evaluated by measuring the temperature difference (Δ T) between the high-temperature heat exchanger 114 side and the low-temperature heat exchanger 113 side at the end of the magnetic cooling apparatus 101 in the magnetic cooling cycle.

In the cycles of steps 1 to 4, the flow rate of the refrigerant 107 may be 20mm/s or more, 30mm/s or more, 40mm/s or more, or 50mm/s or more. The flow rate of refrigerant 107 may be 80mm/s or less, 75mm/s or less, 70mm/s or less, or 65mm/s or less. When the flow rate is 20mm/s or more, the amount of heat moving in the magnetic cooling device 101 per unit time becomes large, and the magnetic cooling device can function well as a cooling device. When the flow rate is less than 80mm/s, power consumption due to pressure loss is significantly reduced, and in addition, heat exchange inside the magnetic material particles 106 is sufficiently performed, and the magnetic material particles can function well as a cooling device. The "flow velocity" of the refrigerant 107 is a linear velocity calculated by dividing the discharge velocity of the refrigerant transport device 109 during operation by the cross-sectional area of the gas storage portion 105.

The conditions of the particle diameter d (μm) of the magnetic material particles 106 and the flow velocity v (mm/s) of the refrigerant 107 provided in the magnetic cooling device and the volume fraction x (vol%) of the inert gas 108 in the hollow container 102 at this time can satisfy the following relationship.

x≤2.1v²D, and x is more than or equal to 1 and less than or equal to 12 (1)

The expression (1) indicates that the smaller the particle size and the faster the flow rate, the more the inert gas 108 is easily stirred, within a range of a predetermined particle size and a predetermined flow rate. If the inert gas is excessively introduced in relation to the relational expression between the particle diameter and the flow velocity, a part of the introduced inert gas is not agitated and remains in an upper portion in the magnetic cooling device 101, and therefore the effect of reducing the heat capacity of the entire magnetic cooling device 101 is greater than the effect of agitating in the wake region, and it is estimated that Δ T is reduced.

According to the present embodiment, the temporal and spatial variations in the flow of the inert gas between the magnetic material particles 106 are utilized, so that the wake region of the magnetic material particles 106 can be efficiently stirred, and the heat exchange performance between the magnetic material particles 106 and the refrigerant 107 can be improved. Thereby, the magnetic cooling apparatus 101 having high cooling capability based on the magnetocaloric effect can be provided.

[ examples ] A method for producing a compound

The present invention will be described more specifically below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[ example 1-1 ]

In order to examine the change in Δ T due to the introduction amount of the inert gas constituting the material-filled portion 103, the magnetic cooling device 111 as shown in fig. 2 was continuously operated, and Δ T1 hour after the start of the operation was measured. The specific configuration of the magnetic cooling device 101 of the present embodiment is as follows.

(Material filling portion 103)

The magnetic material particles 106 were 90g in terms of Gd-based alloy having an average particle diameter of 600 μm. The filling rate of the magnetic material particles 106 was 62 vol% of the material filling portion 103. The low temperature from the material filling part 103 for the magnetocaloric effect to be easily exhibitedSide to high temperature side, by Gd_0.95Y_0.05、Gd_0.975Y_0.025And Gd, the magnetic material particles 106 were filled in a multilayered manner at a weight ratio of 1:1: 2. As the inert gas, pure water was used as the refrigerant 107, and 1 vol% of nitrogen was introduced into the hollow vessel 102.

(gas storage 105)

The hollow vessel 102 is a cylindrical vessel having an inner diameter of Φ 14mm, and is configured such that a lid is attached to both ends thereof, the lid is provided with a pipe having an outer diameter of Φ 6.35mm coaxially connected to the hollow vessel 102, and the second inert gas 110 is prevented from flowing out of the magnetic cooling device 101 by keeping the longitudinal direction of the hollow vessel 102 horizontal to the ground. The volume fraction of the gas storage portion 105 in the hollow container 102 was 40 vol%.

(Material partition 104)

The material separating portion 104 was a stainless steel mesh with a mesh size of 0.06mm, and the magnetic material particles 106 in the material filling portion 103 were fixed thereto.

The magnetic cooling device 111 used for the evaluation was configured as follows.

(refrigerant transporting device 109)

The refrigerant delivery device 109 uses a piston pump with an inner diameter of Φ 25 mm. The flow rate of the refrigerant 107 when the refrigerant transporting device 109 is operated is 60 mm/s.

(Heat exchanger 113 for Low temperature and Heat exchanger 114 for high temperature)

As the low-temperature heat exchanger 113 and the high-temperature heat exchanger 114, copper pipes having an outer diameter of 6.35mm and a length of 0.5m were used.

(magnetic field modulation device 115)

The magnetic field modulation device 115 is constituted by a magnetic circuit using a permanent magnet, and can apply a magnetic field of 1.0T on average to the magnetic cooling apparatus 101. The magnetic field modulation device 115 is connected to the electric cylinder, and can change the relative position with respect to the magnetic cooling device 101 by reciprocating, thereby changing the intensity of the magnetic field applied to the magnetic cooling device 101 between 0T and 1.0T. The reciprocating motion was operated continuously at 0.5 Hz. The results of the Δ T measurement are shown in table 1. A magnetic cooling cycle was performed in the same manner except that the first inert gas 108 and the second inert gas 110 of the magnetic cooling apparatus 101 were replaced with the refrigerant 107, and the increase in Δ T compared to this case is also shown in table 1.

[ examples 1-2 ]

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 2 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

[ examples 1 to 3]

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 6 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

[ examples 1 to 4]

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 10 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

[ examples 1 to 5]

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 12 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

Comparative examples 1 to 1

A magnetic cooling cycle was performed in the same manner as in example 1, except that the first inert gas 108 and the second inert gas 110 were replaced with the refrigerant 107. The results of the measurement evaluation of Δ T are shown in table 1.

Comparative examples 1 and 2

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 0.5 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

Comparative examples 1 to 3

A magnetic cooling cycle was performed in the same manner as in example 1-1, except that the volume fraction of the inert gas in the hollow vessel was changed to 14 vol%. The results of the measurement evaluation of Δ T are shown in table 1.

[ example 2-1 ]

In order to examine the influence of the particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 on Δ T when the volume fraction of the first inert gas 108 in the hollow vessel was 1 vol%, a magnetic cooling cycle was performed in the same manner as in example 1-1 except that the volume fraction of the inert gas in the hollow vessel was set to 1 vol%, and the flow rate of the refrigerant 107 and the average particle size of the magnetic material particles 106 were replaced with 20mm/s and 100 μm, respectively. The results of the Δ T measurement are shown in table 2. The magnetic cooling cycle was performed in the same manner as in the case where the first inert gas 108 and the second inert gas 110 of the magnetic cooling apparatus 101 were replaced with the refrigerant 107, and the increase in Δ T compared with this case is also shown in table 2.

[ examples 2-2 ]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 3]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 4]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 5]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 6]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 7]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 8]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 9]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ examples 2 to 10]

A magnetic cooling cycle was performed in the same manner as in example 2-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 2.

[ example 3-1 ]

A magnetic cooling cycle was performed in the same manner as in example 2-1 except that the volume fraction of the inert gas in the hollow container was replaced with 4 vol% in order to examine the influence of the particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 on Δ T when the volume fraction of the first inert gas 108 in the hollow container was 4 vol%. The results are shown in table 3. Note that the magnetic cooling cycle was performed in the same manner except that the inactive gas of the magnetic cooling apparatus 101 was replaced with the refrigerant 107, and the increase in Δ T compared with this case is also shown in table 3.

[ examples 3-2 ]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 40mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ examples 3 to 3]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 60mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ examples 3 to 4]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 80mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ examples 3 to 5]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 60mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ examples 3 to 6]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 1000 μm and 80mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ examples 3 to 7]

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 80mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

Comparative example 3-1

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 20mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

Comparative examples 3 and 2

A magnetic cooling cycle was performed in the same manner as in example 3-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 40mm/s, respectively. The results of the measurement evaluation of Δ T are shown in table 3.

[ example 4-1 ]

A magnetic cooling cycle was performed in the same manner as in example 2-1 except that the volume fraction of the inert gas in the hollow container was replaced by 7 vol% in order to examine the influence of the particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 on Δ T when the volume fraction of the first inert gas 108 in the hollow container was 7 vol%. The results are shown in table 3. Also, a magnetic cooling cycle was similarly performed except that the first inert gas 108 and the second inert gas 110 of the magnetic cooling apparatus 101 were replaced with the refrigerant 107, and the increase amount of Δ T compared with this case is also shown in table 3.

(example 4-2)

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

[ examples 4 to 3]

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

[ examples 4 to 4]

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

[ examples 4 to 5]

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative example 4-1

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative examples 4 and 2

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative examples 4 to 3

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative examples 4 to 4

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative examples 4 to 5

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

Comparative examples 4 to 6

A magnetic cooling cycle was performed in the same manner as in example 4-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 4.

[ example 5-1 ]

In order to examine the influence of the particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 on Δ T when the volume fraction of the first inert gas 108 in the hollow vessel was 10 vol%, a magnetic cooling cycle was performed in the same manner as in example 2-1 except that the volume fraction of the inert gas in the hollow vessel was 10 vol%, and the average particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 40mm/s, respectively. The results are shown in table 5. Note that, the magnetic cooling cycle was performed in the same manner except that the inactive gas of the magnetic cooling apparatus 101 was replaced with the refrigerant 107, and the increase amount of Δ T compared with this case is also shown in table 5.

[ examples 5-2 ]

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

[ examples 5 to 3]

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

[ examples 5 to 4]

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative example 5-1

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative examples 5 and 2

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative examples 5 to 3

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative examples 5 to 4

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced by 2000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative examples 5 to 5

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced by 2000 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

Comparative examples 5 to 6

A magnetic cooling cycle was performed in the same manner as in example 5-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 5.

[ example 6-1 ]

In order to examine the influence of the particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 on Δ T when the volume fraction of the first inert gas 108 in the hollow vessel was 12 vol%, a magnetic cooling cycle was performed in the same manner as in example 2-1 except that the volume fraction of the inert gas in the hollow vessel was set to 12 vol%, and the average particle size of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 100 μm and 40mm/s, respectively. The results are shown in table 6. Note that, the magnetic cooling cycle was performed in the same manner except that the inactive gas of the magnetic cooling apparatus 101 was replaced with the refrigerant 107, and the increase in Δ T compared with this case is also shown in table 6.

[ example 6-2 ]

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

[ examples 6 to 3]

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were changed to 100 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

[ examples 6 to 4]

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative example 6-1

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative examples 6 and 2

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 1000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative examples 6 to 3

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 20mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative examples 6 to 4

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced by 2000 μm and 40mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative examples 6 to 5

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced by 2000 μm and 60mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

Comparative examples 6 to 6

A magnetic cooling cycle was performed in the same manner as in example 6-1, except that the average particle diameter of the magnetic material particles 106 and the flow rate of the refrigerant 107 were replaced with 2000 μm and 80mm/s, respectively. The results of the evaluation of Δ T measurement are shown in table 6.

It is understood from example 1 and comparative example 1 that when the volume fraction of the inert gas in the hollow container is less than 1 vol%, the effect of increasing Δ T is not exhibited. This is because, when the volume fraction of the inert gas in the hollow container is small, the inert gas stays at the interface between the hollow container 102 and the magnetic material particles 106 constituting the magnetic cooling device 101, and the wake region of the magnetic material particles 106 cannot be stirred. Further, as is clear from comparison between comparative examples 1-1 and 1-3, when the volume fraction of the inert gas in the hollow vessel is greater than 13 vol%, the Δ T is decreased without the effect of increasing Δ T. This is because the increase in the amount of compression of the inert gas makes it difficult to control the actual refrigerant transportation, and in addition, the effect of the decrease in the heat capacity of the entire magnetic cooling equipment 101 due to the decrease in the volume fraction of the refrigerant 107 is greater than the effect of the increase in Δ T due to the wake region stirring.

As is clear from examples 2 to 6 and comparative examples, under the conditions that the flow rate of the refrigerant 107 is large and the particle size of the magnetic material particles 106 is small, the effect of increasing Δ T by the introduction of the first inert gas 108 is exhibited. From examples 2 to 6 and comparative examples, it is understood that when the volume fraction of the inert gas in the hollow container is 1 to 12 vol%, Δ T becomes larger than that in the case where the inert gas is not contained. It is also found that if the volume fraction of the inert gas in the hollow container is 6 to 10 vol%, Δ T becomes larger.

When the particle diameter of the magnetic material particle 106 and the flow rate of the refrigerant 107 satisfy a certain condition, an increasing effect of Δ T is produced by the introduction of the inert gas, and it is known that the conditions of the particle diameter of the magnetic material particle 106 and the flow rate of the refrigerant 107 for increasing Δ T vary depending on the amount of the inert gas. From these results, a relationship that the particle diameter d (μm) of the magnetic material particle 106 having an effect of increasing Δ T by the introduction of the inert gas, the flow velocity v (mm/s) of the refrigerant 107, and the volume fraction x (vol%) of the inert gas 108 in the hollow container 102 was satisfied was obtained.

As a result, it was found that when the following relationship is satisfied, the effect of increasing Δ T by the introduction of the inert gas is exhibited.

x≤2.1v²D, and x is more than or equal to 1 and less than or equal to 12 (1)

[ TABLE 1]

[ TABLE 2]

[ TABLE 3]

[ TABLE 4]

[ TABLE 5]

[ TABLE 6]

While the embodiments have been described above, it should be understood that various modifications may be made to the embodiments without departing from the spirit and scope of the claims.

[ industrial applicability ]

The magnetic cooling device of the present invention has high heat exchange performance between a magnetic material having a magnetocaloric effect and a refrigerant, and can be used for cooling (refrigeration). For example, the present invention can be applied to a refrigerator, a freezer, a cooling device used in a part of a hydrogen liquefaction process, and a temperature control device such as an air conditioner and a heat retention device.