Magnetic attraction force type magnetic refrigeration device

Abstract

To provide a magnetic refrigeration device which can obtain a further higher magnetic field and a further quicker cycle.SOLUTION: A magnetic refrigeration device comprises: a vessel 80 composed of a material which is high in thermal conductivity, and having a space which is partitioned into three chambers of a high-temperature part 82, a magnetic refrigeration working chamber 84 and a low-temperature part 86; a magnetic refrigeration material 88 movably accommodated in the magnetic refrigeration working chamber 84 in a center axial direction; and an electromagnet 10 for generating a strong magnetic field with the vicinity of an upper partitioning plate 83 arranged between the high-temperature part 82 and the magnetic refrigeration working chamber 84 as a center of the magnetic field, located at a peripheral edge side of the vessel 80; and a power supply device 30 which can supply a supply current to the electromagnet 10 while time-changing the supply current at a prescribed pattern. The magnetic refrigeration device transmits heat to the high-temperature part 82 from the low-temperature part 86 by using a magnetic refrigeration cycle which generates a magnetic refrigeration effect by the heat-insulative excitation / demagnetization of the magnetic field to the magnetic refrigeration material 88.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a magnetic refrigeration apparatus suitable for use in, for example, producing liquid hydrogen. [Background technology]

[0002] The basic principle of magnetic refrigeration is the so-called Carnot cycle, which transfers heat from a low temperature area to a high temperature area by repeating four processes: adiabatic excitation, high temperature contact, adiabatic demagnetization, and low temperature contact (see, for example, Patent Document 2). Currently, various methods have been developed to achieve this, but they can be roughly categorized into the following two types: (i) A method of using a permanent magnet to move the magnet closer to and further away from the magnetic refrigeration material (see, for example, Patent Document 1) (ii) A method of inserting and removing magnetic refrigeration materials into and from a superconducting magnet (see, for example, Patent Document 2)

[0003] In Patent Document 1, there is an upper limit to the magnetic force (up to about 1 Tesla), and in Patent Document 2, it is possible to generate a stronger magnetic field than in Patent Document 1, but this has the disadvantage that the magnetic force applied to the magnetic refrigeration material is therefore greater, and the external work required to extract it becomes very large, making it impossible to apply a strong magnetic field of tens of Tesla or more than 10 Tesla. Another problem is that it may be necessary to synchronize with a thermal switch to transfer heat in accordance with the heat generation process when a magnetic field is applied and the heat absorption process when demagnetizing, which has the disadvantage of making the system fundamentally complex.

[0004] In the "adiabatic excitation" and "adiabatic demagnetization" processes, it may be possible to turn the magnetic field generation on and off instantly, but there are issues with this being impossible with permanent magnets, and even with superconducting magnets, it is impossible to do this "instantly (adiabatically)" due to the characteristics of the superconducting wire. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-147136 A [Patent Document 2] U.S. Patent No. 4,332,125 [Non-patent literature]

[0006] [Non-Patent Document 1] Akiko Saito, "Magnetic Refrigeration Technology to Achieve Freon-Free Environment," Toshiba Review Vol. 62 p. 76-77 (2007) Summary of the Invention [Problem to be solved by the invention]

[0007] The disadvantages of the background art include the following: (i) The magnetic field generation cannot be turned on and off instantly, and as a result, the magnetic refrigeration material needs to be relatively separated or pulled out from the magnet against a large magnetic force; (ii) In order to transfer heat, it is necessary to physically contact the magnetic refrigeration material with the high-temperature or low-temperature part inside or outside the magnet, or to transfer a fluid, etc., which requires a complex mechanism such as synchronizing with the generation of the magnetic field as described in Patent Document 1. Furthermore, (i) determines the upper limit of the magnetic field, and (ii) determines the upper limit of the time efficiency. Even if a magnetic refrigeration cycle can be realized in principle, there is a fundamental problem that it is currently not possible to realize a stronger magnetic field or a faster cycle.

[0008] Therefore, in order to solve the problem of (i) above, we thought that if we could turn the magnetic field generation on and off at high speed, we could realize the ideal "adiabatic excitation" and "adiabatic demagnetization" processes. Next, regarding the problem of (ii) above, we believe that it is possible to realize a thermal switch in which thermal contact with high-temperature and low-temperature parts is synchronized with the generation of a magnetic field without a complicated mechanism by utilizing the magnetic force that draws the magnetic refrigeration material or thermal switch toward the center of the magnetic field when a magnetic field is applied, and the gravity acting on the magnetic refrigeration material or thermal switch in the absence of a magnetic field. Furthermore, the inventors thought that a new magnetic refrigeration system could be realized by combining the solutions of (i) and (ii) and controlling the time waveform of the generated magnetic field, and thus arrived at the present invention. [Means for solving the problem]

[0009] [1] As shown in FIG. 1, for example, the magnetic refrigeration apparatus of the present invention is a magnetic refrigeration apparatus comprising: a container 80 made of a material with high thermal conductivity and having a space partitioned into three compartments, a high-temperature section 82, a magnetic refrigeration work chamber 84, and a low-temperature section 86; a magnetic refrigeration material 88 housed in the magnetic refrigeration work chamber 84 so as to be movable in the central axis direction; an electromagnet 10 for generating a strong magnetic field having a magnetic field center in the vicinity of an upper partition plate 83 provided between the high-temperature section 82 and the magnetic refrigeration work chamber 84, the electromagnet 10 being located on the peripheral side of the container 80; and a power supply unit 30 capable of supplying a current to the electromagnet 10 while changing the supply current over time in a predetermined pattern; Heat is transferred from the low temperature portion 86 to the high temperature portion 82 by a magnetic refrigeration cycle that generates a magnetic refrigeration effect by adiabatic excitation and demagnetization of a magnetic field to the magnetic refrigeration material 88 .

[0010] [2] In the magnetic refrigeration device of the present invention [1], as shown in FIG. 2, preferably, the magnetic refrigeration device has a lower partition plate 85 provided between a low-temperature section 86 and a magnetic refrigeration work chamber 84, and the magnetic refrigeration cycle includes an adiabatic excitation process (S200) in which power is supplied from a power supply device 30 to an electromagnet 10 to turn on a magnetic field applied to a container 80, and a magnetic refrigeration material 88 is attracted from the lower partition plate 85 side to the vicinity of an upper partition plate 83 during the adiabatic excitation process, and the temperature of the magnetic refrigeration material 88 increases while the magnetic refrigeration material 88 is attracted from the lower partition plate 85 side to the vicinity of an upper partition plate 83 (S205). In the state where the temperature of the magnetic refrigeration material 88 has increased, the magnetic refrigeration material 88 comes into contact with the upper partition plate 83 and is heated. Heat is transferred from the low temperature section 86 to the high temperature section 82 through one cycle consisting of a high temperature contact process (S210) in which heat is transferred to the high temperature section 82, an adiabatic demagnetization process (S220) in which, after a certain period of time, the power supply from the power supply unit 30 to the electromagnet 10 is turned off and the magnetic field applied to the container 80 is demagnetized, and during the adiabatic demagnetization process, the magnetic refrigeration material 88 is released from contact with the upper partition plate 83 and its temperature drops (S225), and the magnetic refrigeration material 88 moves inside the container 80 toward the lower partition plate 85 and comes into thermal contact with the lower partition plate 85, thereby absorbing heat from the low temperature section 86, and a low temperature contact process (S230). [3] In the magnetic refrigeration apparatus [2] of the present invention, as shown in, for example, FIG. 1, during the adiabatic demagnetization process, the contact between the magnetic refrigeration material 88 and the upper partition plate 83 is preferably separated by gravity or the working fluid contained in the magnetic refrigeration work chamber 84. [4] In the magnetic refrigeration device [2] or [3] of the present invention, the on / off of the magnetic field during the adiabatic excitation process or the adiabatic demagnetization process may include a delay time that corresponds to the magnetic field generation response time to the on / off of the power supply from the power supply device to the electromagnet. [5] In the magnetic refrigeration device [1] to [4] of the present invention, it is preferable to further include a high-temperature side heat transport medium in thermal contact with the high-temperature part 82 and a low-temperature side heat transport medium in thermal contact with the low-temperature part 86. [6] In the magnetic refrigeration device of the present invention [1] to [5], the material with high thermal conductivity may have a thermal conductivity of 80 W / m·K or more.

[0011] [7] As shown in Figs. 13 and 15, the magnetic refrigeration apparatus of the present invention comprises a container (90, 100) made of a material with high thermal conductivity and having a space partitioned into four compartments: a high-temperature section (91, 102), a thermal switch movement space (94, 104), a magnetic refrigeration material chamber (98, 108), and a low-temperature section (96, 106); a magnetic refrigeration material (98, 108) having one end fixed to the low temperature section side and the other end located on the thermal switch movement space side; an electromagnet for generating a strong magnetic field with a magnetic field center in the vicinity of the center of the magnetic refrigeration material, the electromagnet being located on the peripheral side of the container; A thermal switch (93, 103) located in the thermal switch movement space and including a magnetic body; A power supply device capable of supplying a current to the electromagnet while changing the supply current over time in a predetermined pattern, A magnetic refrigeration cycle generates a magnetic refrigeration effect by adiabatic excitation and demagnetization of a magnetic field to the magnetic refrigeration material, and switches the thermal switch between a state in which it is in contact with the magnetic refrigeration material and a state in which it is in contact with the high-temperature portion, thereby transferring heat from the low-temperature portion to the high-temperature portion. [8] In the magnetic refrigeration device [7] of the present invention, as shown in, for example, FIG. 13, preferably, the high temperature section 91 is installed above the direction of gravity, the low temperature section 96 is installed below the high temperature section 91, and a spring 92 is provided to provide a restoring force for maintaining the thermal switch 93 in contact with the high temperature section 91, and the restoring force of the spring 92 is configured to be weaker than the magnetic attractive force on the thermal switch 93 due to excitation of the electromagnet. [9] In the magnetic refrigeration apparatus [7] of the present invention, as shown in, for example, FIG. 15, it is preferable that the high temperature section 102 is installed below the direction of gravity, the low temperature section 106 is installed above the high temperature section 102, and the weight of the thermal switch 108 is lighter than the magnetic attractive force on the thermal switch 103 due to excitation of the electromagnet.

[10] In the magnetic refrigeration device [7] of the present invention, as shown in, for example, Figs. 14 and 16, preferably, the magnetic refrigeration cycle has an initial state in which the power supply from the power supply device to the electromagnet is turned off to turn off the magnetic field applied to the magnetic refrigeration material (S1400, S1600) and the thermal switch is in contact with the high-temperature portion (S1405, S1605); an adiabatic excitation process (S1410, S1610) in which power is supplied from the power supply device to the electromagnet to turn on the magnetic field applied to the magnetic refrigeration material, and the thermal switch moves from the high temperature part side to the low temperature part side within the thermal switch movement space; The magnetic refrigeration material comes into contact with the thermal switch in a high-temperature contact process (S1415, S1615) to transfer heat to the thermal switch. After a certain time has elapsed, an adiabatic demagnetization process (S1420, S1620) is performed in which the power supply from the power supply device to the electromagnet is turned off to demagnetize the magnetic field applied to the magnetic refrigeration material. During the adiabatic demagnetization process, the thermal switch is separated from the magnetic refrigeration material and moves to the high temperature part (S1425, S1625), a heat absorption process (S1430, S1630) in which the thermal switch moves from the low temperature portion to the high temperature portion within the thermal switch movement space and comes into thermal contact with the high temperature portion; It is preferable to transport heat from the low temperature part to the high temperature part in one cycle.

[11] In the magnetic refrigeration apparatus of any one of [7] to

[10] of the present invention, the material with high thermal conductivity may have a thermal conductivity of 80 W / m·K or more.

[0012]

[12] In the magnetic refrigeration devices [1] to

[11] of the present invention, the power supply device 30 preferably includes a power storage unit 32 having at least one of a storage battery or a large-capacity capacitor, a current waveform setting unit 70 which sets the current waveform to be supplied to the electromagnet 10, and a current control unit 60 which supplies a current to drive the electromagnet 10 from the power storage unit 32 in response to a waveform control signal from the current waveform setting unit 70.

[13] In the magnetic refrigeration device

[12] of the present invention, the large-capacity capacitor is preferably an electric double-layer capacitor, an oil-immersed charge-discharge capacitor, or a chemical capacitor.

[14] In the magnetic refrigeration apparatus

[12] or

[13] of the present invention, preferably, the current supplied to the electromagnet 10 by the current control unit 60 is greater than or equal to 300 amperes and less than or equal to 30,000 amperes, and the applied voltage is greater than or equal to 15 volts and less than or equal to 400 volts.

[15] In the magnetic refrigeration apparatuses

[12] to

[14] of the present invention, the power supply device 30 is preferably further connected to a commercial power supply 31 for charging.

[16] In the magnetic refrigeration devices

[12] to

[15] of the present invention, the current waveform setting unit 70 preferably generates a waveform control signal instructing a stepped waveform.

[17] In the magnetic refrigeration apparatus of the present invention

[12] to

[16] , the electromagnet 10 is preferably a Bitter type electromagnet or a wound type electromagnet.

[18] In the magnetic refrigeration apparatus of the present invention

[12] to

[17] , the strong magnetic field is preferably 1 Tesla or more and 70 Tesla or less. Preferably, the strong magnetic field is more than 20 Tesla and 70 Tesla or less, and is a higher value than the magnetic field that can be generated by a superconducting magnet alone. Effect of the Invention

[0013] The magnetic refrigeration device of the present invention turns the magnetic field on and off, eliminating the need for the reciprocating motion of pulling the magnetic refrigeration material out of the magnet when a magnetic field is generated and returning it to the magnet when the magnetic field is zero, making the system configuration extremely simple. In addition, since it can be turned on and off quickly, about one second, it is expected to improve the efficiency of the magnetic refrigeration cycle. Furthermore, by improving the "variable waveform magnetic field generator," it will be possible to develop a system with a magnetic field of over 5 Tesla, depending on the power supply. According to the magnetic refrigeration device of the present invention, thermal contact between the high temperature and low temperature parts occurs by utilizing magnetic force and gravity when the magnetic field is generated and terminated, so no complicated mechanism is required, and an optimal magnetic refrigeration cycle can be realized by adjusting the time waveform of the magnetic field generation. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram illustrating a magnetic refrigeration device used in the present invention, and explains the operation using a magnetic refrigeration cycle. [Diagram 2] 2 is a flowchart illustrating the operation of the Carnot cycle of the device shown in FIG. 1. [Diagram 3] FIG. 4 is a diagram showing temperature changes due to operation of the magnetic refrigeration device of the present invention. [Figure 4] 1 is a functional block diagram illustrating a power supply device using a storage battery according to an embodiment of the present invention, and a control system for controlling the power supply device. [Diagram 5] FIG. 5 is a waveform diagram of an output current of the device shown in FIG. [Figure 6] FIG. 1 is a diagram showing the configuration of a Bitter magnet according to one embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing the configuration of a circular metal plate which is a component of the Bitter magnet shown in FIG. 6. [Figure 8] 1 is a waveform diagram showing various generated magnetic field waveforms according to one embodiment of the present invention. [Figure 9] FIG. 11 is a waveform diagram of a step-like magnetic field when the maximum current value is changed, showing one embodiment of the present invention. [Figure 10] FIG. 2 is a waveform diagram illustrating generation of a stepped magnetic field repeated five times according to one embodiment of the present invention. [Figure 11] FIG. 5 is a schematic configuration diagram of a magnetic refrigeration device showing a second embodiment of the present invention. [Figure 12] FIG. 12 is a schematic diagram showing the internal configuration of a container used in the magnetic refrigeration apparatus shown in FIG. [Figure 13] FIG. 11 is a schematic configuration diagram illustrating a magnetic refrigeration device according to a third embodiment of the present invention, and explains the operation using a magnetic refrigeration cycle. [Figure 14] 14 is a flowchart illustrating the operation of the Carnot cycle of the device shown in FIG. 13. [Figure 15] FIG. 11 is a schematic configuration diagram for explaining a magnetic refrigeration device according to a fourth embodiment of the present invention, and explains the operation using a magnetic refrigeration cycle. [Figure 16] 16 is a flowchart illustrating the operation of the Carnot cycle of the device shown in FIG. 15. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An embodiment of the present invention will now be described with reference to the drawings. 1 is a schematic diagram for explaining the magnetic refrigeration device used in the present invention, and explains the operation using a magnetic refrigeration cycle, where (A) shows the initial process (low-temperature contact process), (B) shows the adiabatic excitation process, (C) shows the high-temperature contact process, and (D) shows the adiabatic demagnetization process. The magnetic refrigeration cycle used in the present invention is a Carnot cycle, which consists of four processes: adiabatic excitation, high-temperature contact, adiabatic demagnetization, and low-temperature contact.

[0016] The magnetic refrigeration device used in the present invention comprises an electromagnet 10 , a power supply unit 30 , a container 80 , a high temperature section 82 , a magnetic refrigeration working chamber 84 , a low temperature section 86 , a magnetic refrigeration material 88 , an upper partition plate 83 , and a lower partition plate 85 . The container 80 is a cylindrical container having a space divided into three compartments: a high-temperature section 82, a magnetic refrigeration working chamber 84, and a low-temperature section 86, which are made of a material with high thermal conductivity, and is provided as a magnetic refrigeration operating section housed coaxially with the electromagnet 10. The upper partition plate 83 is provided between the high temperature section 82 and the magnetic refrigeration working chamber 84. The lower partition plate 85 is provided between the low temperature section 86 and the magnetic refrigeration working chamber 84. A high temperature side heat transport medium in thermal contact with the high temperature section 82 flows in the high temperature section 82, and exchanges heat with, for example, a high temperature side heat exchanger. A low temperature side heat transport medium in thermal contact with the low temperature section 86 flows in the low temperature section 86, and exchanges heat with, for example, a low temperature side heat exchanger. The magnetic refrigeration material 88 is accommodated in the magnetic refrigeration working chamber 84 so as to be movable in the central axis direction, and can be in thermal contact with the high temperature section 82 and / or the low temperature section 86. For the magnetic refrigeration material 88, a magnetic refrigeration material containing, for example, gadolinium is used. The material with high thermal conductivity is preferably a material having a value that allows heat exchange even if the magnetic refrigeration material 88 is in thermal contact with the high temperature part 82 and / or the low temperature part 86 for a short time, and for example, a thermal conductivity of 80 W / m·K or more is preferable, more preferably, for example, copper having 400 W / m·K or more, and the most suitable material is, for example, diamond or carbon nanotube having 1000 to 5500 W / m·K or more. Metallic materials with thermal conductivity of 80 W / m·K or more include silver, copper, gold, aluminum, magnesium, metallic silicon, zinc, nickel, iron, etc., and alloys thereof, such as aluminum alloys and brass, are also included. Ceramic materials with thermal conductivity of 80 W / m·K or more include aluminum nitride and silicon carbide.

[0017] The electromagnet 10 is an electromagnet 10 for generating a strong magnetic field with its magnetic field center in the vicinity of an upper partition plate 83 provided between a high temperature part 82 of a container 80 and a magnetic refrigeration working chamber 84. The power supply device 30 is capable of supplying a current to the electromagnet 10 while varying the current over time in a predetermined pattern. The electromagnet 10 and the power supply unit 30 will be described in detail later.

[0018] Next, the operation of the thus configured device will be described with reference to the flowchart of FIG. In the figure, in the adiabatic excitation process, when power is supplied from the power supply 30 to the electromagnet 10 and a magnetic field is instantaneously applied to the container 80 (S200), the magnetic refrigeration material 88 is attracted toward the upper partition plate 83 and its temperature rises (S205). In the high temperature contact process, the magnetic refrigeration material 88 comes into contact with the upper partition plate 83 in a heated state and transfers heat to the high temperature portion (S210). In the adiabatic demagnetization process, after a certain period of time has elapsed, the power supply from the power supply unit 30 to the electromagnet 10 is turned off to demagnetize the magnetic field applied to the container 80 (S220), and the magnetic refrigeration material 88 is released from contact with the upper partition plate 83 due to gravity, and the temperature drops (S225). In the high temperature contact process, the magnetic refrigeration material falls inside the container 80 and comes into contact with the lower partition plate 85, and then comes into contact with the low temperature part through the lower partition plate 85 and absorbs the heat of the low temperature part (S230).

[0019] By repeating the above steps, including adjusting the time for generating the magnetic field, heat is discharged from the low temperature part to the high temperature part, the magnetic refrigeration cycle (four processes: adiabatic excitation, high temperature contact, adiabatic demagnetization, and low temperature contact) is generated, and heat is transferred by the magnetic refrigeration effect caused by the adiabatic excitation and demagnetization of the magnetic field. Preferably, the heat capacity of the high temperature part 82 is appropriately designed according to the heat capacity of the object to be cooled, thereby realizing a magnetic refrigeration device that corresponds to the production amount of liquid hydrogen, for example. Fig. 3 is a diagram showing an example of temperature change during operation of the magnetic refrigeration device of the present invention. This is experimental data obtained by repeatedly turning the magnetic field on and off using the magnetic refrigeration device of the present invention. With room temperature as the reference temperature, a temperature difference of about ±0.2°C occurs near the upper and lower partition plates after about 60 seconds, indicating the magnetic refrigeration effect.

[0020] FIG. 4 is a functional block diagram of a power supply device using a storage battery for use in a magnetic refrigeration device, showing an embodiment of the present invention. In the magnetic refrigeration device of the present invention, for example, a Bitter-type electromagnet or a wound-type electromagnet is used as the electromagnet 10 capable of handling a large current for generating a strong magnetic field. Here, the strong magnetic field is preferably 1 Tesla or more and 70 Tesla or less, and preferably more than 20 Tesla and 70 Tesla or less, and is a value higher than the magnetic field that can be generated by a superconducting magnet alone. The large current is, for example, a maximum of 30,000 amperes, and the lower limit is the minimum current required for generating a strong magnetic field, and may be, for example, 3,000 amperes, or more preferably, 300 amperes. The applied voltage is preferably a maximum of 400 volts, and the lower limit is the minimum voltage required for generating a strong magnetic field, and may be, for example, 40 volts, or more preferably, 15 volts.

[0021] It is preferable that the power supply device 30 can supply a current to the electromagnet 10 while changing the supply current over time in a predetermined pattern. For this purpose, it is preferable that the power supply device 30 uses a storage battery or a small, large-capacity capacitor, and can quickly control and adjust the amount of current, for example, a maximum applied current of 30,000 amperes and a maximum applied voltage of 400 volts from the storage portion in response to an external waveform input from the signal generator 70 as a current waveform setting unit. A storage battery is a device that converts electrical energy into chemical energy, stores it, and can extract electricity as needed, and can be used repeatedly by recharging. They are also called batteries or secondary batteries, and there are various types, such as lead-acid batteries, nickel-metal hydride batteries, NAS (sodium-sulfur) batteries, and lithium-ion batteries.

[0022] The large-capacity capacitor may be an electric double-layer capacitor, an oil-filled charge-discharge capacitor, or a chemical capacitor. An electric double-layer capacitor has a capacitor structure with opposing electrodes using an electric double layer as a dielectric, and has a capacitance of, for example, several tens of F (farads). Here, the electric double layer refers to a state in which electrons or holes attract each other and are aligned due to charging, which occurs spontaneously between a solid and a liquid. An oil-filled charge-discharge capacitor uses a paper processed from wood pulp impregnated with insulating oil as a dielectric. Because of its simple structure, an oil-filled charge-discharge capacitor has the drawback that it becomes larger in size in order to increase the capacitance, but it has excellent voltage resistance. A chemical capacitor is also called an aluminum electrolytic capacitor, and uses an oxide film (aluminum oxide) formed on the surface of an aluminum electrode (usually aluminum foil) as a dielectric. A chemical capacitor can obtain a large capacity because the dielectric layer is very thin. By combining the electromagnet 10 with the power supply unit 30, a magnetic field generating system can be realized that allows the generation of any magnetic field duration and any magnetic field waveform.

[0023] FIG. 4 is a functional block diagram of a power supply device using a storage battery according to an embodiment of the present invention, and also shows a control system for controlling the power supply device. In the diagram, a power supply device 30 of the present invention includes a charging commercial power source 31, a storage battery 32, a control block 40 for large currents, a current output circuit 50, and a feedback control block 60. The charging commercial power source 31 is a power supply system for charging the storage battery 32, and a relatively small-scale power supply contract with a supply power of about several kW, such as a commercial low-voltage power source, is sufficient, but a high-voltage power supply system used in a normal steady-state magnetic field generator that requires liquid helium or large power may also be used. The high-voltage power supply system has a supply voltage of, for example, 6.6 kV and can handle a supply power of about several MW. The power supply device 30 includes a smoothing capacitor 33, a control circuit power supply 34, and an operation and monitoring circuit 36 ​​in addition to the storage battery 32. The storage battery 32 supplies DC power and has a rated voltage of, for example, 16V to 400V and a rated current of, for example, 1 to 30kA. The smoothing capacitor 33 smoothes the current and voltage supplied by the storage battery 32 and is connected in parallel to a large current compatible control block 40 to the positive and negative terminals of the storage battery 32. The control circuit power supply 34 provides power for the operation and monitoring circuit 36 ​​from a commercial power source. The operation and monitoring circuit 36 ​​monitors the terminal voltage and supply current of the storage battery 32 and provides input voltage information to the PWM circuit 66. The operation and monitoring circuit 36 ​​can also function as an auxiliary power supply and may be configured to supply power for storage to the storage battery 32. By providing the storage battery 32, even if charging is performed using a commercial power source 31 for charging under a relatively small-scale power supply contract with a supply capacity of several kW, such as a commercial low-voltage power source, it becomes possible to temporarily supply a large current from the storage battery 32. This eliminates the need for a power supply contract of several MW as in the case of factories and large commercial facilities, and allows the contracted ampere number to be reduced, resulting in lower electricity bills.

[0024] The large current compatible control block 40 has a field effect transistor (FET) 42, a drive circuit 44, a smoothing capacitor 46, a diode 47, and an inductor Lf 48. The field effect transistor 42 receives a PWM control signal from a pulse width modulation circuit 66 at its gate terminal to perform on / off control of the drain current between its drain terminal and source terminal. The smoothing capacitor 46 and the diode 47 are connected to the positive and negative terminals of the storage battery 32 with the field effect transistor 42 in between. The inductor Lf 48 is inserted between the field effect transistor 42 and the current output circuit 50. The current output circuit 50 has a capacitor Cf 52 and a common mode coil CM, and outputs an output current for exciting the Bitter-type magnet 10 between output terminals P and N.

[0025] The feedback control block 60 has the output current detection transformer 54, a buffer amplifier 58, an error amplifier 62, a duty cycle limiting circuit 64, and a pulse width modulation circuit (PWM) 66. The buffer amplifier 58 receives the detection signal of the output current detection transformer 54 and is used, for example, to monitor the output current. The error amplifier 62 compares the output current detection transformer 54 with a pattern signal of the duty cycle limiting circuit 64 and sends the result to the pulse width modulation circuit 66. The duty cycle limiting circuit 64 limits the amount of current change per unit time (dI / dt), and also limits the upper limit of the duty ratio of the pulse width modulation circuit 66 when the error signal of the error amplifier 62 is large, thereby preventing the Bitter-type magnet 10 from being damaged by an excessive current. The signal generator 70 outputs a pattern signal to the duty cycle limiting circuit 64, which indicates the drive current waveform to be supplied to the Bitter-type magnet 10. The personal computer 72 is equipped with software that makes it easy to indicate the drive current waveform pattern to the signal generator 70, and a general-purpose computer device is used.

[0026] In the device configured in this manner, the signal generator 70 is controlled from the personal computer 72, and a voltage profile having the same waveform as the magnetic field to be generated is sent to the duty cycle limiting circuit 64. Figure 5 is a waveform diagram of the output current of the device shown in Figure 4. In the case of an electric double-layer capacitor or an electromagnet, there is a limit to the allowable range of the current increment per unit time, so the output current waveform diagram is specified within this limit.

[0027] In the duty cycle limiting circuit 64, the DC current from the storage battery 32 is controlled in accordance with the pattern signal sent from the signal generator 70, and a current flows through the circular metal plate 12 of the Bitter coil connected to the output terminals P and N of the current output circuit 50, generating a magnetic field. In addition, when generating a pulsed magnetic field, it is possible to generate a magnetic field of 30 Tesla or more for 1 millisecond using electrical energy stored in a high-capacity capacitor system. Therefore, by using this Bitter coil as is, it is sufficient to withstand a strong magnetic field of about 30 Tesla. Heat generated by the coil is quickly cooled by circulating pure water inside the magnet using a small circulating cooler.

[0028] FIG. 6 is a diagram showing the configuration of a Bitter-type electromagnet, showing one embodiment of the present invention. FIG. 7 is a perspective view showing the configuration of a circular metal plate, which is a component of the Bitter magnet shown in FIG. 6. In the figure, the Bitter-type magnet 10 has a circular metal plate 12, an insulating plate 14, a flange 16, and a clamping rod 18. The Bitter-type magnet is not a coiled wire, but is structured by stacking circular conductive metal plates and insulating spacers in a spiral shape. Current flows in a spiral shape between the circular metal plates. The purpose of the laminated circular metal plate using a copper-silver alloy is to withstand the enormous mechanical pressure to the outside caused by the Lorentz force due to the magnetic field acting on the moving charges in the circular metal plate, which increases in proportion to the square of the magnetic field strength. In addition, water is circulated as a coolant through holes in the circular metal plate to dissipate the enormous heat generated in the circular metal plate by resistance heating due to the large current flowing through the circular metal plate. The amount of heat dissipation increases in proportion to the square of the magnetic field strength.

[0029] The circular metal plate 12 is a roughly circular plate made by punching copper or a strong copper alloy, and has slits 122, notched holes 124 for fastening rods, a hole 126 for cooling water, and a central hole 128. The circular metal plate 12 uses a Bitter coil for generating a strong magnetic field, which uses a copper-silver alloy, a high-strength, highly conductive material. The applicant uses this Bitter coil for both generating a steady strong magnetic field and a pulsed magnetic field, and has a track record of generating a magnetic field of up to about 30 Tesla by supplying 15 megawatts of power to generate a steady strong magnetic field. The slits 122 rotate between adjacent layers by an angle corresponding to the notch angle of the wedge-shaped notch 142; for example, in the case of 45 degrees, one rotation takes eight sheets, and in the case of 30 degrees, one rotation takes twelve sheets. The insulating plate 14 is, for example, a plate made of polyimide resin, and is formed with a wedge-shaped cutout portion 142, a notched hole 144 for a tightening rod, a hole 146 for cooling water, and a central hole 148. The wedge-shaped cutout portion 142 is formed by cutting a part of the circumferential surface at a predetermined angle, for example, about 30 degrees to 45 degrees, from the axial direction into the circumferential portion. The laminated circular metal plates 12 form one turn of the coil by establishing electrical continuity with adjacent circular metal plates 12 at the cutout portion 146 of the insulating plate 14 as a stacked coil, and by establishing insulation with adjacent circular metal plates 12 at the insulating plate 14 excluding the cutout portion 146.

[0030] The flanges 16 are provided at both axial ends of the Bitter-type magnet 10, and are made of, for example, FRP disks, and have the rigidity to support the fastening force of the fastening rods 18. The fastening rods 18 fasten the overlapping coil laminate of the circular metal plate 12 and the insulating plate 14, and for example, eight of them are provided at equal intervals in the axial direction. The fastening rods 18 are attached to the corresponding fastening rod cutout holes 124, 144 of each layer, and since they are attached along the peripheral surface of the circular metal plate 12, a fastening ring 182 is provided in a position close to the flange 16 side to fasten and hold the fastening rods.

[0031] The high magnetic field introduction path 20 communicates with the central hole 128 of the circular metal plate 12 and the central hole 148 of the insulating plate 14, and is an introduction path for sending an object to be observed into the high magnetic field space generated by the Bitter-type magnet 10. The electrodes 22 have electric wire connection terminals provided on the surfaces of the flanges 16 at both ends, and are connected to both side ends of the stacked circular metal plates 12. The cooling water supply pipe 24 is a pipe that supplies cooling water to the cooling water holes 126 of the corresponding circular metal plates 12 of each layer and the cooling water holes 146 of the insulating plates 14, and has cooling water connection ports on the surfaces of the flanges 16 at both ends. 6 It is advisable to use deionized distilled water with a viscosity of Ω·cm. The cooling water supplied from the cooling water supply pipe 24 exchanges heat with the heat generated by the generation of a high magnetic field in the Bitter-type magnet 10.

[0032] Figure 8 is a waveform diagram showing various generated magnetic field waveforms according to one embodiment of the present invention. Figure 8(A) shows a magnetic field actually generated by inputting a trigonometric function waveform, and Figure 8(B) shows a stepped magnetic field. The entire generation time of the stepped magnetic field is about 2 seconds, and the constant portion of the stepped shape is about 0.2 seconds.

[0033] Figure 9 shows the waveform of a stepped magnetic field generated by changing the current. It can be seen that the magnetic field is generated according to the maximum current.

[0034] Figure 10 shows the measurement results of repeatedly generating a stepped magnetic field, which was repeated five times in this case. In principle, this can be repeated until the battery runs out of energy. This type of repeated magnetic field is the same as turning a magnetic field on and off, and it could be used for magnetic refrigeration, etc.

[0035] In the above embodiment, the electromagnet for generating a strong magnetic field is a Bitter-type electromagnet, but a wound-type electromagnet may be used. Also, in the above embodiment, the power storage unit is a storage battery, but a large-capacity capacitor may be used. In addition, in the above embodiment, a structure is shown in which thermal contact between the high temperature part and the low temperature part occurs by utilizing magnetic force and gravity when the magnetic field is generated and when the magnetic field ends, but the present invention is not limited to this, and may be combined with a configuration in which the magnetic refrigeration material is driven back and forth by the working fluid contained in the magnetic refrigeration work chamber.

[0036] Fig. 11 is a schematic diagram of a magnetic refrigeration device showing a second embodiment of the present invention. In Fig. 11, components having the same functions as those in Fig. 1 are given the same reference numerals and their explanation will be omitted. In this embodiment, a high-temperature side bellows 82b and a high-temperature side drive rod 82c, as well as a low-temperature side bellows 86b and a low-temperature side drive rod 86c are provided for the reciprocating motion of a magnetic refrigeration material 88 in a magnetic refrigeration work chamber 84. A high-temperature side heat exchanger 82a and a low-temperature side heat exchanger 86a are provided for heat exchange between the high-temperature section 82 and the low-temperature section 86. A geared motor 94 drives, via a drive wheel 92, the up-and-down reciprocating motion of a drive rod 90, the other end of which is connected to the high-temperature side bellows 82b.

[0037] Fig. 12 is a schematic diagram of the inside of a container used in the magnetic refrigeration apparatus shown in Fig. 11. The magnetic refrigeration material 88 has a layered structure 88a, and the outer wall is surrounded by a thin-walled container 88b. The high-temperature side drive rod 82c and the low-temperature side drive rod 86c are attached to the magnetic refrigeration material 88 using supports 89a. The mesh 89b forms the boundaries between the layered structures 88a and allows the fluid to diffuse, helping to make the temperature distribution inside the magnetic refrigeration material 88 uniform.

[0038] 13 is a schematic diagram for explaining a magnetic refrigeration device according to a third embodiment of the present invention, and explains the operation using a magnetic refrigeration cycle, where (A) shows the initial process (heat absorption process), (B) shows the adiabatic excitation process, (C) shows the high-temperature contact process, and (D) shows the adiabatic demagnetization and heat absorption process. The magnetic refrigeration cycle used in the present invention is a Carnot cycle, which consists of four processes, namely, adiabatic excitation, high-temperature contact, adiabatic demagnetization, and heat absorption process.

[0039] The magnetic refrigeration device used in the third embodiment comprises a container 90, a high temperature section 91, a spring 92, a thermal switch 93, a thermal switch movement space 94, a low temperature section 96, and a magnetic refrigeration material 98; the electromagnets and power supply are omitted from the illustration. The container 90 is a cylindrical container having a space partitioned into four chambers: a high-temperature section 91 made of a material with high thermal conductivity, a thermal switch movement space 94, a magnetic refrigeration material chamber 99, and a low-temperature section 96. A high-temperature side heat transport medium in thermal contact with the high-temperature section 91 flows in the high-temperature section 91, and exchanges heat with, for example, a high-temperature side heat exchanger. A low-temperature side heat transport medium in thermal contact with the low-temperature section 96 flows in the low-temperature section 96, and exchanges heat with, for example, a low-temperature side heat exchanger.

[0040] The magnetic refrigeration material chamber 99 is a chamber or space that contains a magnetic refrigeration material 98. One end of the magnetic refrigeration material 98 is fixed to the low-temperature section 96 side, and the other end is located on the thermal switch movement space 94 side. The magnetic refrigeration material 98 is, for example, a magnetic refrigeration material containing gadolinium. The thermal switch 93 includes a magnetic material, and has a state in which it is in contact with the high-temperature portion 91 by the spring 92, and a state in which it is in thermal contact with the magnetic refrigeration material 98 by magnetic attraction. The magnetic material of the thermal switch 93 may be covered with a metal plate or inorganic ceramic fiber to reinforce the magnetic material if it is brittle. The spring 92 provides a restoring force that maintains the state in which the thermal switch 93 is in contact with the high-temperature portion 91. The restoring force of the spring 92 is configured to be weaker than the magnetic attraction force on the thermal switch 93 caused by excitation of the electromagnet.

[0041] FIG. 14 is a flow chart illustrating the operation of the Carnot cycle of the device shown in FIG. In the initial state, the power supply from the power supply device to the electromagnet is turned off to turn off the magnetic field applied to the magnetic refrigeration material 98 (S1400), and the thermal switch 93 is in contact with the high temperature portion 91 by the spring 92 (S1405). In the adiabatic excitation process, power is supplied from the power supply to the electromagnet to turn on the magnetic field applied to the magnetic refrigeration material 98, and the thermal switch 93 moves within the thermal switch movement space 94 from the high temperature section 91 side to the low temperature section 96 (S1410). In the high temperature contact process, the magnetic refrigeration material 98 comes into contact with the thermal switch 93 in a heated state, and transfers heat to the thermal switch 93 (S1415). In the adiabatic demagnetization process, after a certain period of time has elapsed, the power supply to the electromagnet is turned off to demagnetize the magnetic field applied to the magnetic refrigeration material 98 (S1420), and the thermal switch 93 is released from contact with the magnetic refrigeration material 98 by the restoring force of the spring 92 and moves toward the high temperature portion 91 (S1425). In the heat absorption process, the thermal switch 93 moves from the low temperature section 96 side to the high temperature section 91 within the thermal switch 93 movement space, and comes into thermal contact with the high temperature section 91 (S1430). In the Carnot cycle operation of the device shown in FIG. 13, heat is transported from the low temperature part 96 to the high temperature part 91 through one cycle consisting of the above-mentioned initial process (heat absorption process), adiabatic excitation process, high temperature contact process, and adiabatic demagnetization / heat absorption process.

[0042] 15 is a schematic diagram for explaining a magnetic refrigeration device according to a fourth embodiment of the present invention, and explains the operation using a magnetic refrigeration cycle, where (A) shows the initial process (heat absorption process), (B) shows the adiabatic excitation process, (C) shows the high-temperature contact process, and (D) shows the adiabatic demagnetization and heat absorption process. The magnetic refrigeration cycle used in the present invention is a Carnot cycle, which consists of four processes, namely, adiabatic excitation, high-temperature contact, adiabatic demagnetization, and heat absorption process.

[0043] The magnetic refrigeration device used in the fourth embodiment includes a container 100, a high temperature section 102, a thermal switch 103, a magnetic refrigeration working chamber 104, a low temperature section 106, and a magnetic refrigeration material 108, but electromagnets and a power supply are not shown. The container 100 is a cylindrical container having a space divided into four compartments: a high-temperature section 102 made of a material with high thermal conductivity, a thermal switch movement space 104, a magnetic refrigeration material chamber 109, and a low-temperature section 106, and is provided as a magnetic refrigeration operating section housed coaxially with the electromagnet 10. A high-temperature side heat transport medium flows in the high-temperature section 102 and is in thermal contact with the high-temperature section 102, and exchanges heat with, for example, a high-temperature side heat exchanger. A low-temperature side heat transport medium flows in the low-temperature section 106 and is in thermal contact with, for example, a low-temperature side heat exchanger.

[0044] The magnetic refrigeration material chamber 109 is a chamber or space that contains the magnetic refrigeration material 108. One end of the magnetic refrigeration material 108 is fixed to the low temperature section 106 side, and the other end is located on the thermal switch movement space 104 side. The magnetic refrigeration material 108 is, for example, a magnetic refrigeration material containing gadolinium. The thermal switch 103 includes a magnetic material, and has a state in which it is in contact with the high-temperature part 101 due to gravity, and a state in which it is in thermal contact with the magnetic refrigeration material 108 due to magnetic attraction. The weight of the thermal switch 103 is lighter than the magnetic attraction force acting on the thermal switch 103 due to excitation of the electromagnet. The magnetic material of the thermal switch 103 may be covered with a metal plate or inorganic ceramic fiber to reinforce the magnetic material if it is brittle.

[0045] FIG. 16 is a flow chart illustrating the operation of the Carnot cycle of the device shown in FIG. In the initial state, the power supply from the power supply device to the electromagnet is turned off to turn off the magnetic field applied to the magnetic refrigeration material 108 (S1600), and the thermal switch 103 is in contact with the high temperature portion 102 due to gravity (S1605). In the adiabatic excitation process, power is supplied from the power supply device to the electromagnet to turn on the magnetic field applied to the magnetic refrigeration material 108, and the thermal switch 103 moves from the high temperature section 102 side to the low temperature section 106 within the thermal switch movement space (S1610). In the high temperature contact process, the magnetic refrigeration material 108 comes into contact with the thermal switch 103 in a state where the temperature has increased, and transfers heat to the thermal switch 103 (S1615). In the adiabatic demagnetization process, after a certain period of time has elapsed, the power supply to the electromagnet is turned off to demagnetize the magnetic field applied to the magnetic refrigeration material 108 (S1620), and the thermal switch 103 is released from contact with the magnetic refrigeration material 108 due to gravity and moves toward the high temperature part 102 (S1625). In the heat absorption process, thermal switch 103 moves from the low temperature section 106 side to the high temperature section 102 within the thermal switch 103 movement space, and comes into thermal contact with the high temperature section 102 (S1630). In the Carnot cycle operation of the device shown in Figure 15, heat can be transported from the low temperature part 106 to the high temperature part 102 through one cycle consisting of the above-mentioned initial process (heat absorption process), adiabatic excitation process, high temperature contact process, and adiabatic demagnetization / heat absorption process.

[0046] It should be noted that the above-described embodiments are merely examples of the present invention, and the scope of the claims should not be interpreted in a restrictive manner. Various substitutions that are obvious to those skilled in the art are included in the scope of the claims. [Industrial Applicability]

[0047] According to the magnetic refrigeration device of the present invention, since it is possible to control the on / off of the magnetic field at a high repetition frequency, it is possible to provide a magnetic refrigeration device that can realize a stronger magnetic field and a faster cycle compared to conventional devices. [Explanation of symbols]

[0048] 10: Bitter type electromagnet 12:Circular metal plate 122: Slit 124: Notched hole for tightening rod 126: Cooling water hole 128: Central hole 14: Insulating plate 142: Wedge-shaped cutout 144: Notched hole for tightening rod 146: Cooling water hole 148: Central hole 16: Flange 18: Clamping rod 182: Fastening ring 20: High magnetic field introduction path 22: Electrode 24: Cooling water supply pipe 30: Power supply 31: Commercial power supply for charging 32: Battery 40: Control block for large current 50: Current output circuit 60: Feedback control block 70: Signal generator (signal waveform setting section) 72: Personal computer (PC) 80, 90, 100: Container 82, 91, 102: High temperature section 83: Upper partition plate 84: Magnetic refrigeration chamber 85: Lower partition plate 86, 96, 106: Low temperature section 88, 98, 108: Magnetic refrigeration materials 92: Spring 93, 103: Thermal switch (encapsulated in magnetic material) 94, 104: Thermal switch moving space 99, 109: Magnetic Refrigeration Materials Room

Claims

1. a container made of a material with high thermal conductivity and having a space partitioned into three compartments: a high-temperature section, a magnetic refrigeration working chamber, and a low-temperature section; a magnetic refrigeration material accommodated in the magnetic refrigeration work chamber so as to be movable in the central axis direction; an electromagnet for generating a strong magnetic field with a magnetic field center in the vicinity of an upper partition plate provided between the high-temperature section and the magnetic refrigeration work chamber, the electromagnet being located on the peripheral edge side of the container; a power supply device capable of supplying a supply current to the electromagnet while changing the supply current over time in a predetermined pattern; A magnetic refrigeration device comprising: The magnetic refrigeration device transfers heat from the low temperature portion to the high temperature portion by a magnetic refrigeration cycle that generates a magnetic refrigeration effect by adiabatic excitation and demagnetization of a magnetic field on the magnetic refrigeration material.

2. the magnetic refrigeration device has a lower partition plate provided between the low-temperature portion of the container and the magnetic refrigeration working chamber, The magnetic refrigeration cycle comprises: an adiabatic excitation step of turning on power supply from the power supply device to the electromagnet to apply a magnetic field to the container; During the adiabatic excitation process, the magnetic refrigeration material is attracted from the lower partition plate side to the vicinity of the upper partition plate, and the temperature of the magnetic refrigeration material increases. a high-temperature contact process in which the magnetic refrigeration material comes into contact with the upper partition plate in a temperature-raised state and transfers heat to the high-temperature portion; an adiabatic demagnetization step in which, after a certain time has elapsed, the power supply from the power supply device to the electromagnet is turned off to demagnetize the magnetic field applied to the container; During the adiabatic demagnetization process, the magnetic refrigeration material is released from contact with the upper partition plate and its temperature drops. a low-temperature contact process in which the magnetic refrigeration material moves inside the container toward the lower partition plate and comes into thermal contact with the lower partition plate, thereby absorbing heat from the low-temperature section; 2. The magnetic refrigeration apparatus according to claim 1, wherein heat is transported from the low temperature section to the high temperature section in one cycle.

3. 3. The magnetic refrigeration apparatus according to claim 2, wherein the magnetic refrigeration material is separated from the upper partition plate during the adiabatic demagnetization process by gravity or a working fluid contained in the magnetic refrigeration work chamber.

4. 4. The magnetic refrigeration device according to claim 2, wherein the on / off of the magnetic field during the adiabatic excitation process or the adiabatic demagnetization process includes a delay time corresponding to a magnetic field generation response time in response to the on / off of power supply from the power supply device to the electromagnet.

5. a high-temperature side heat transport medium that is in thermal contact with the high-temperature portion of the container; a low-temperature side heat transport medium that is in thermal contact with the low-temperature portion of the container; 2. The magnetic refrigeration device according to claim 1, further comprising:

6. 2. The magnetic refrigeration apparatus according to claim 1, wherein the material with high thermal conductivity has a thermal conductivity of 80 W / m·K or more.

7. a container made of a material with high thermal conductivity and having a space partitioned into four compartments: a high-temperature section, a thermal switch movement space, a magnetic refrigeration material chamber, and a low-temperature section; a magnetic refrigeration material having one end fixed to the low-temperature section side and the other end located on the thermal switch movement space side; an electromagnet for generating a strong magnetic field with a magnetic field center near the center of the magnetic refrigeration material, the electromagnet being located on the periphery of the container; a thermal switch located within the thermal switch movement space and including a magnetic material; a power supply device capable of supplying a supply current to the electromagnet while changing the supply current over time in a predetermined pattern; A magnetic refrigeration device comprising: The magnetic refrigeration device transfers heat from the low temperature section to the high temperature section by switching the thermal switch between a state in which it is in contact with the magnetic refrigeration material and a state in which it is in contact with the high temperature section through a magnetic refrigeration cycle that generates a magnetic refrigeration effect by adiabatic excitation and demagnetization of a magnetic field on the magnetic refrigeration material.

8. Furthermore, the high temperature section is installed above the direction of gravity, and the low temperature section is installed below the high temperature section; a spring that provides a restoring force to maintain the thermal switch in contact with the high-temperature portion; The restoring force of the spring is configured to be weaker than the magnetic attractive force to the thermal switch due to excitation of the electromagnet. The magnetic refrigeration device according to claim 7.

9. Furthermore, the high temperature section is installed below the direction of gravity, and the low temperature section is installed above the high temperature section; The weight of the thermal switch is lighter than the magnetic attraction force to the thermal switch due to the excitation of the electromagnet. The magnetic refrigeration device according to claim 7.

10. The magnetic refrigeration cycle comprises: an initial state in which the power supply from the power supply device to the electromagnet is turned off to turn off the magnetic field applied to the magnetic refrigeration material, and the thermal switch is in contact with the high-temperature portion; an adiabatic excitation process in which power is supplied from the power supply device to the electromagnet to turn on the magnetic field applied to the magnetic refrigeration material, and the thermal switch moves from the high temperature side to the low temperature side within the thermal switch movement space; a high-temperature contact process in which the magnetic refrigeration material comes into contact with the thermal switch in a heated state and transfers heat to the thermal switch; an adiabatic demagnetization step in which, after a certain time has elapsed, the power supply from the power supply device to the electromagnet is turned off to demagnetize the magnetic field applied to the magnetic refrigeration material; During the adiabatic demagnetization process, the thermal switch is separated from the magnetic refrigeration material and moves to the high temperature part, a heat absorption process in which the thermal switch moves from the low temperature section to the high temperature section within the thermal switch movement space and comes into thermal contact with the high temperature section; 8. The magnetic refrigeration apparatus according to claim 7, wherein heat is transported from the low temperature section to the high temperature section in one cycle.

11. 11. The magnetic refrigeration apparatus according to claim 7, wherein the material with high thermal conductivity has a thermal conductivity of 80 W / m·K or more.

12. The power supply device a power storage unit having at least one of a storage battery and a large-capacity capacitor; a power supply unit that supplies charging power to the power storage unit; a current waveform setting unit that sets a current waveform to be supplied to the electromagnet; a current control unit that supplies a current for driving the electromagnet from the power storage unit in response to a waveform control signal from the current waveform setting unit; 2. The magnetic refrigeration device according to claim 1, further comprising:

13. 13. The magnetic refrigeration apparatus according to claim 12, wherein the large-capacity capacitor is an electric double-layer capacitor, an oil-filled charge-discharge capacitor, or a chemical capacitor.

14. 13. The magnetic refrigeration apparatus according to claim 12, wherein the current supplied to the electromagnet by the current control unit is between 300 amperes and 30,000 amperes, and the applied voltage is between 15 volts and 400 volts.

15. The magnetic refrigeration apparatus according to claim 12, wherein the power supply device is further connected to a commercial power source for charging.

16. The magnetic refrigeration apparatus according to claim 12, wherein the current waveform setting unit generates a waveform control signal that instructs a stepped waveform.

17. 13. The magnetic refrigeration apparatus according to claim 12, wherein the electromagnet is a Bitter-type electromagnet or a wound-type electromagnet.

18. 8. The magnetic refrigeration apparatus according to claim 1, wherein the strong magnetic field generated by the electromagnet for generating a strong magnetic field is 1 tesla or more and 70 tesla or less.

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