Magnetic refrigerator

Abstract

This magnetic refrigerator comprises: a thermally insulated tank; a working container which is fixed within the thermally insulated tank, has an inflow port and an outflow port for a process fluid, and is filled with the process fluid; a magnetic working substance which is placed inside the working container, comes into direct contact with the process fluid, generates heat when excited, and absorbs heat when demagnetized; a magnetic field generating device which is disposed within the thermally insulated tank, and which surrounds the side surfaces of the working container when the working container is caused to advance thereinto; and a magnetic field generating device moving structure which moves the magnetic field generating device back and forth in a predetermined direction within the thermally insulated tank to advance the working container into the magnetic field generating device to excite the magnetic working substance, and withdraw the working container from the magnetic field generating device to demagnetize the magnetic working substance.

Description

magnetic refrigerator

[0001] The present disclosure relates to a magnetic refrigerator for cooling a fluid.

[0002] 2. Description of the Related Art Magnetic refrigerators have been known for some time now, which cool an object by utilizing the magnetocaloric effect, in which the temperature of a magnetic body changes reversibly by repeating magnetization and demagnetization.

[0003] For example, a magnetic refrigerator described in Patent Document 1 includes a container for liquefying a cryogenic fluid such as liquid hydrogen, a superconducting magnet arranged around the container, and a piston arranged inside the container and made up of multiple magnetic bodies connected via a thermal switch and a non-magnetic body. Furthermore, a rod that is raised and lowered by a motor is connected to the upper end of the piston. When the piston is raised and lowered by the rod, the magnetic body generates and absorbs heat due to the magnetocaloric effect.

[0004] Patent No. 3233811

[0005] For example, as in Patent Document 1, when a magnetic body placed in a container containing a fluid is moved vertically to generate or absorb heat, a rod that penetrates the top of the container and moves up and down by a drive device such as a motor is connected to the magnetic body. In such a case, a seal is provided at the portion where the rod penetrates the container, but there is a high risk that the seal will be damaged by frequent movement of the rod up and down, resulting in leakage of the fluid in the container. In addition, there is a risk of heat being input from the drive device to the fluid in the container via the rod.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a magnetic refrigerator that can reduce the risk of process fluid leakage and prevent heat input from the drive device to the process fluid.

[0007] In order to achieve the above-mentioned object, a magnetic refrigerator according to one aspect of the present disclosure comprises an insulated tank, a working vessel fixed within the insulated tank, having an inlet and outlet for a process fluid, and filled with the process fluid, a magnetic working material installed within the working vessel and in direct contact with the process fluid, which generates heat when excited and absorbs heat when demagnetized, a magnetic field generating device arranged within the insulated tank and which surrounds the sides of the working vessel when the working vessel is advanced therethrough, and a magnetic field generating device moving structure which moves the magnetic field generating device back and forth in a predetermined direction within the insulated tank, thereby advancing the working vessel into the magnetic field generating device to magnetize the magnetic working material, and moving the working vessel out of the magnetic field generating device to demagnetize the magnetic working material.

[0008] The present disclosure has the above-described configuration and advantageously provides a magnetic refrigerator that can reduce the risk of leakage of the process fluid and prevent heat input from the drive device to the process fluid.

[0009] Fig. 1 is a schematic diagram showing the general configuration of a magnetic refrigeration system including a magnetic refrigerator according to this embodiment. Fig. 2 is a schematic side view of the magnetic refrigerator viewed from one horizontal direction. Fig. 3 is a schematic side view of the magnetic refrigerator viewed from a horizontal direction 90 degrees different from that of Fig. 2. Fig. 4 is a schematic side view of the magnetic refrigerator when the magnet is moved from the state shown in Fig. 3.

[0010] Preferred embodiments of the present disclosure will be described below with reference to the drawings. Note that, in the following, identical or corresponding elements throughout the drawings will be designated by the same reference numerals, and redundant explanations thereof may be omitted. Furthermore, the drawings are schematic illustrations of the respective components for ease of understanding, and the shapes, dimensional ratios, and the like may not be accurately depicted. Furthermore, the present disclosure is not limited to the following embodiments.

[0011] 1 is a schematic diagram showing the overall configuration of a magnetic refrigeration system including a magnetic refrigerator according to this embodiment. The magnetic refrigeration system 10 shown in Fig. 1 includes a magnetic refrigerator 2, a feed line 3 that supplies a process fluid to a working vessel 21 of the magnetic refrigerator 2, and a refrigerant discharge line 4 and a heat exhaust line 5 that discharge the process fluid from the working vessel 21. The magnetic refrigeration system 10 also includes a return line 6 that returns the process fluid discharged to the heat exhaust line 5 to the working vessel 21.

[0012] <Magnetic refrigerator 2> The magnetic refrigerator 2 includes a heat-insulating tank 20 configured as a vacuum tank with the inside kept in a vacuum state, a working vessel 21 fixed in the heat-insulating tank 20, a magnetic working material 22 installed in the working vessel 21, a cylindrical magnetic field generator 23 arranged in the heat-insulating tank 20, and a magnetic field generator moving structure 30 shown in Fig. 2 etc. In the following description, the magnetic field generator 23 may be referred to as a magnet 23, and the magnetic field generator moving structure 30 may be referred to as a magnet moving structure 30.

[0013] The working vessel 21 is filled with a liquid process fluid, which is the fluid to be cooled. A first inlet 24 and a second inlet 26, which are inlet ports for the process fluid, are arranged at a lower end portion 21a of the working vessel 21. A first outlet 25 and a second outlet 27, which are outlet ports for the process fluid, are arranged at an upper end portion 21b of the working vessel 21. Within the working vessel 21, the process fluid flows from the lower end portion 21a to the upper end portion 21b. Since the working vessel 21 is arranged within the thermal insulation tank 20, the interior of the working vessel 21 is insulated from the outside.

[0014] The magnetic working material 22 is made of a magnetic material called a magnetic refrigeration material, and generates heat when excited and absorbs heat when demagnetized. The magnetic working material 22 is arranged apart from the lower end portion 21a and the upper end portion 21b in the working vessel 21. That is, the magnetic working material 22 is arranged in the flow of the process fluid in the working vessel 21 and exchanges heat with the process fluid through direct contact. The magnetic working material 22 is provided with a flow path for the process fluid. The form of the magnetic working material 22 is not particularly limited, but for example, the magnetic working material 22 is made of a large number of particles contained in a vessel, and flow paths through which the process fluid can pass are formed between the particles.

[0015] The magnet 23 is, for example, an electromagnet such as a superconducting magnet or a permanent magnet. The magnet 23 is moved in a vertical direction relative to the magnetic working material 22 by a magnet moving structure 30 shown in Fig. 2 etc., thereby switching between excitation and demagnetization of the magnetic working material 22. The magnet moving structure 30 will be described in detail later.

[0016] <Feed Line 3> The feed line 3 is connected to the first inlet 24 of the working vessel 21 of the magnetic refrigerator 2. The feed line 3 is composed of piping or the like. The process fluid flowing through the feed line 3 is liquid. However, the process fluid flowing through the feed line 3 is not strictly limited to liquid, and may be in a gas-liquid two-phase state with a small amount of air bubbles present in the liquid. A feed valve V1 is arranged in the feed line 3. The feed valve V1 is an on-off valve or a flow rate adjustment valve, and switches between communication between the feed line 3 and the working vessel 21 and blockage. When the feed valve V1 is open, the process fluid is supplied from the feed line 3 to the magnetic refrigerator 2, and when the feed valve V1 is closed, the supply of the process fluid from the feed line 3 to the magnetic refrigerator 2 is blocked.

[0017] <Cold Discharge Line 4> The cold discharge line 4 is connected to the first outlet 25 of the working vessel 21 of the magnetic refrigerator 2. The cold discharge line 4 is composed of piping or the like. During steady operation, a process fluid that is at a lower temperature than the process fluid that has flowed into the working vessel 21, i.e., the process fluid that has been cooled in the working vessel 21, is discharged to the cold discharge line 4. A cold discharge valve V2 is arranged in the cold discharge line 4. The cold discharge valve V2 is an on-off valve or a flow rate adjustment valve, and switches between communication between the working vessel 21 and the cold discharge line 4 and blockage. When the cold discharge valve V2 is open, the process fluid is discharged from the working vessel 21 to the cold discharge line 4, and when the cold discharge valve V2 is closed, discharge of the process fluid from the working vessel 21 to the cold discharge line 4 is prevented.

[0018] <Heat Exhaust Line 5> The heat exhaust line 5 is connected to the second outlet 27 of the working vessel 21 of the magnetic refrigerator 2. The heat exhaust line 5 is composed of piping or the like. During steady-state operation, a process fluid having a higher temperature than the process fluid that has flowed into the working vessel 21, i.e., the process fluid whose temperature has been increased in the working vessel 21, is discharged to the heat exhaust line 5. A hot heat exhaust valve V4 is arranged in the heat exhaust line 5. The hot heat exhaust valve V4 is an on-off valve or a flow rate adjustment valve, and switches between communication between the working vessel 21 and the heat exhaust line 5 and blockage. When the hot heat exhaust valve V4 is open, the process fluid is discharged from the working vessel 21 to the heat exhaust line 5, and when the hot heat exhaust valve V4 is closed, discharge of the process fluid from the working vessel 21 to the heat exhaust line 5 is prevented.

[0019] A cooler 51 is disposed downstream of the heat exhaust valve V4 in the heat exhaust line 5. The cooler 51 cools the process fluid by heat exchange between the process fluid flowing through the heat exhaust line 5 and the refrigerant flowing through the refrigerant line 7. The process fluid cooled by the cooler 51 is sent to a buffer tank 52 and temporarily stored therein.

[0020] <Return line 6> The return line 6 connects the buffer tank 52 and the second inlet 26 of the working vessel 21. The return line 6 is composed of piping or the like. The liquid process fluid stored in the buffer tank 52 is returned to the working vessel 21 through the return line 6. The working vessel 21, the exhaust heat line 5, and the return line 6 form a circulation flow path 50 for the process fluid.

[0021] A pump 53 is disposed in the return line 6. The pump 53 pressurizes the process fluid stored in the buffer tank 52 and sends it to the working vessel 21. A return valve V3 is disposed in the return line 6 downstream of the pump 53. The return valve V3 is an on-off valve or a flow rate adjustment valve, and switches between communication between the return line 6 and the working vessel 21 and blockage. When the return valve V3 is open, the process fluid is supplied from the return line 6 to the magnetic refrigerator 2, and when the return valve V3 is closed, the supply of the process fluid from the return line 6 to the magnetic refrigerator 2 is blocked.

[0022] In this embodiment, the heat exhaust line 5 and the return line 6 constitute a circulation line 8. Therefore, a first end of the circulation line 8 is connected to a second inlet 26 of the working vessel 21, and a second end of the circulation line 8 is connected to a second outlet 27 of the working vessel 21. The feed valve V1, the cold discharge valve V2, the return valve V3, and the hot discharge valve V4 may be included in the magnetic refrigerator 2.

[0023] In this embodiment, the process fluid supplied from the feed line 3 to the working vessel 21 is, for example, a liquefied gas produced by cooling a gas such as hydrogen gas or natural gas in a liquefaction device having multiple stages of heat exchangers. In this case, the refrigerant that cools the gas in the liquefaction device may be used as the refrigerant flowing through the refrigerant line 7. In addition, the tip of the cryogenic discharge line 4 may be connected to, for example, a liquefied gas tank, and the process fluid discharged from the working vessel 21 to the cryogenic discharge line 4 may be stored in the liquefied gas tank.

[0024] Next, the magnet moving structure 30 and the like will be described with reference to Figures 2, 3, and 4. Figure 2 is a schematic side view of the magnetic refrigerator 2 viewed from one horizontal direction, and Figure 3 is a schematic side view of the magnetic refrigerator 2 viewed from a horizontal direction that is 90 degrees different from that of Figure 2. Figure 4 is a schematic side view of the magnetic refrigerator 2 when the magnet 23 is moved from the state shown in Figure 3. Figures 2, 3, and 4 mainly show the magnet moving structure 30 that moves the magnet 23 in the vertical direction and related parts, and omit other parts such as piping through which process fluid flows.

[0025] 2 and 3 , the working vessel 21 is, for example, a columnar vessel, and is fixed to the upper end of a support 47 installed in the thermal insulation tank 20. The magnet 23 has a cylindrical internal space 23S that extends vertically and into which the working vessel 21 can enter. The magnet moving structure 30 allows the magnet 23 to move back and forth vertically within the thermal insulation tank 20. This allows the working vessel 21 to enter the internal space 23S of the magnet 23 to magnetize the magnetic working material 22 in the working vessel 21, and the working vessel 21 to withdraw from the internal space 23S to demagnetize the magnetic working material 22 in the working vessel 21.

[0026] The magnet moving structure 30 includes a magnet holder 31 that is placed inside the thermal insulation tank 20 and holds the magnet 23, an actuator 35 that is installed on an installation stand 48 that is placed on the upper outside of the thermal insulation tank 20, and a linear guide 36 that is installed inside the thermal insulation tank 20.

[0027] The magnet holder 31 has a mounting base 32 on which the magnet 23 is placed, two hanging rods 33 whose lower ends are fixed to the mounting base 32 and extend vertically, and an operating plate 34 connected across the upper ends of the two hanging rods 33.

[0028] The mounting base 32 has a horizontal support base 41 on which the magnet 23 is placed and fixed, a vertical plate 42, two support columns 43, and two horizontal plates 44. The magnet 23 is placed and fixed on the support base 41. The lower end of the vertical plate 42 is fixed to one end of the support base 41, and the support columns 43 are fixed to both sides of the magnet 23 on either side of the support base 41. The upper ends of the two support columns 43 and the vertical plate 42 are connected by the horizontal plates 44.

[0029] The lower ends of the hanging rods 33 are fixed to a horizontal plate 44 on a support column 43 of the mounting table 32. The upper ends of the two hanging rods 33 are connected to each other by a main plate 34a of an operating plate 34. The operating plate 34 is composed of a horizontal main plate 34a that is long in the direction connecting the two hanging rods 33, and two reinforcing plates 34b that are fixed to both sides of the main plate 34a in the width direction.

[0030] The magnet moving structure 30 includes an eccentricity / eccentricity absorbing component 37 that connects the magnet holder 31 and the rod 35a of the actuator 35. The center portion of the operating plate 34 of the magnet holder 31 is attached to the tip of the rod 35a of the actuator 35 via the eccentricity / eccentricity absorbing component 37. In other words, the magnet holder 31 is suspended from the tip of the rod 35a of the actuator 35 via the eccentricity / eccentricity absorbing component 37. An example of the eccentricity / eccentricity absorbing component 37 is a floating joint. The actuator 35 is formed, for example, by a hydraulic cylinder and includes a rod 35a that penetrates the top wall of the thermal insulation tank 20, with its tip positioned within the thermal insulation tank 20 and extending and retracting in the vertical direction. A high-pressure differential seal 49, such as a bellows seal, is attached to the portion where the rod 35a penetrates the top wall of the thermal insulation tank 20. This allows a satisfactory vacuum state to be maintained within the thermal insulation tank 20. The actuator 35 may be a hydraulic actuator such as a hydraulic cylinder, a pneumatic actuator such as a pneumatic cylinder, or an electric actuator such as an electric cylinder.

[0031] 2 and 3 show the case where the rod 35a is in a contracted state, and when the rod 35a is extended, the magnet holder 31 holding the magnet 23 descends in the direction of arrow a, resulting in the state shown in Fig. 4. In other words, the actuator 35 can vertically reciprocate the magnet 23 together with the magnet holder 31 by extending and contracting the rod 35a. Here, as shown in Figs. 2 and 3, by bringing the rod 35a of the actuator 35 into a contracted state, the magnet 23 can be moved to a predetermined first position where the magnetic working material 22 in the working vessel 21 is magnetized. Furthermore, as shown in Fig. 4, by bringing the rod 35a into an extended state, the magnet 23 can be moved to a predetermined second position where the magnetic working material 22 is demagnetized.

[0032] The magnetic refrigerator 2 of this example is equipped with two linear guides 36 that guide the reciprocating movement of the magnet holder 31 in the vertical direction, but the number is not limited to two. The linear guides 36 have rails 36b extending in the vertical direction and carriages 36a that slide on the rails 36b. The carriages 36a of the two linear guides 36 are attached to two carriage mounting plates 45 that are long in the vertical direction, and these two carriage mounting plates 45 are fixed to the vertical plates 42 of the magnet holder 31. As a result, when the rod 35a of the actuator 35 extends and retracts, the magnet holder 31 is guided by the linear guides 36, allowing the magnet holder 31 and the magnet 23 to move smoothly in the vertical direction without swaying sideways.

[0033] <Operation Method of Magnetic Refrigeration System 10> Here, an operation method of the magnetic refrigeration system 10 will be described. When the magnetic refrigeration system 10 starts steady-state operation, it repeatedly performs a magnetic refrigeration cycle consisting of (a) an adiabatic excitation process, (b) a heat exhaust process, (c) an adiabatic demagnetization process, and (d) a cooling process, which will be described later. As a result, the temperature of the liquid process fluid supplied from the feed line 3 is lowered and the fluid is discharged to the cold discharge line 4. Note that the operations of the feed valve V1, cold discharge valve V2, return valve V3, hot discharge valve V4, pump 53, and actuator 35, which will be described below, are controlled by, for example, a control device. Furthermore, if the magnet 23 is composed of a superconducting magnet, the coil of the superconducting magnet is always energized during operation.

[0034] (a) Adiabatic excitation step The working vessel 21 is pre-filled with a process fluid. The feed valve V1, cold discharge valve V2, hot discharge valve V4, and return valve V3 are closed, the pump 53 is stopped, and the rod 35a of the actuator 35 is contracted to raise the magnet 23 and magnet holder 31. In this state, the magnet 23 is in the first position described above, and an external magnetic field is applied to the magnetic working material 22 by the magnet 23. The magnetic working material 22, which is thus adiabatically excited, generates heat.

[0035] (b) Heat Rejection Step With the magnets 23 and magnet holders 31 still raised from the adiabatic excitation step, i.e., with the magnetic working material 22 continuously excited, the feed valve V1 and cold discharge valve V2 are kept closed, while the hot discharge valve V4 and return valve V3 are opened and the pump 53 is driven. By driving the pump 53, the liquid process fluid stored in the buffer tank 52 is supplied to the working vessel 21 through the return line 6. In the working vessel 21, the magnetic working material 22 exchanges heat with the process fluid, and the magnetic working material 22 releases heat to the process fluid. The heated process fluid is discharged from the second outlet 27 to the heat rejection line 5.

[0036] (c) Adiabatic demagnetization process The hot heat discharge valve V4 and return valve V3 are closed, the pump 53 is stopped, and the feed valve V1, cold discharge valve V2, hot heat discharge valve V4, and return valve V3 are closed. The rod 35a of the actuator 35 is extended to lower the magnet 23 and magnet holder 31. In this state, the magnet 23 is in the second position described above, and the strength of the magnetic field applied to the magnetic working material 22 by the magnet 23 is reduced. The magnetic working material 22, thus adiabatically demagnetized, absorbs heat from the surroundings.

[0037] (d) Cooling Step With the magnets 23 and magnet holder 31 still in the lowered state from the adiabatic demagnetization step, i.e., with the magnetic working material 22 continuously demagnetized, the feed valve V1 and cold discharge valve V2 are opened while the hot heat discharge valve V4 and return valve V3 are kept closed. This allows the process fluid to be supplied to the working vessel 21 through the feed line 3. In the working vessel 21, the magnetic working material 22 and the process fluid exchange heat, and the magnetic working material 22 absorbs heat from the process fluid. The process fluid, whose temperature has been lowered by the heat absorption of the magnetic working material 22, is discharged from the first outlet 25 to the cold discharge line 4.

[0038] The magnetic refrigeration system 10 may perform an initial cooling operation before steady-state operation. In the initial cooling operation, a magnetic refrigeration cycle consisting of (a) an adiabatic excitation step, (b) a heat dissipation step, (c) an adiabatic demagnetization step, and (d') an initial cooling step is repeated one or more times to store cold energy until a predetermined initial temperature is reached. The initial temperature is any temperature lower than the target cooling temperature of the process fluid. Compared to the magnetic refrigeration cycle during steady-state operation, the magnetic refrigeration cycle for initial cooling performs the (d') initial cooling step described below instead of the (d) cooling step, but the other steps (a), (b), and (c) are the same.

[0039] (d') Initial Cooling Step With the magnets 23 and magnet holder 31 still in the lowered state from the adiabatic demagnetization step, i.e., with the magnetic working material 22 continuously demagnetized, the feed valve V1 and the cold discharge valve V2 are kept closed, the hot discharge valve V4 and the return valve V3 are opened, and the pump 53 is driven. By driving the pump 53, the liquid process fluid stored in the buffer tank 52 is supplied to the working vessel 21 through the return line 6. In the working vessel 21, the magnetic working material 22 and the process fluid exchange heat, and the magnetic working material 22 absorbs heat from the process fluid. The process fluid, whose temperature has been lowered by the heat absorption of the magnetic working material 22, is discharged from the second outlet 27 to the exhaust heat line 5.

[0040] In this initial cooling step, the process fluid is circulated through a circulation flow path 50 consisting of the heat exhaust line 5, the return line 6, and the working vessel 21. However, in the initial cooling step, as in the cooling step in steady operation, the process fluid may be supplied from the feed line 3 to the working vessel 21, and the cooled process fluid may be discharged from the first outlet 25 to the cold discharge line 4. In this case, the initial cooling operation and the steady operation are the same and indistinguishable. Also, in the initial cooling step, with the return valve V3 closed and the pump 53 stopped, the process fluid may be supplied from the feed line 3 to the working vessel 21, and the cooled process fluid may be discharged from the second outlet 27 to the heat exhaust line 5.

[0041] The magnetic refrigeration system 10 described above may reduce the temperature of the liquid process fluid to a subcooled state.

[0042] In this embodiment, the magnet 23 is moved back and forth in the vertical direction to magnetize and demagnetize the magnetic working material 22 in the working vessel 21. The working vessel 21, which is filled with a process fluid, is fixed, and the magnetic working material 22 installed in the working vessel 21 is not moved. This reduces the risk of the process fluid leaking from the working vessel 21. Furthermore, since there is no driving device for moving the magnetic working material 22, which is a magnetic body, heat input from the driving device to the process fluid in the working vessel 21 can be prevented. Furthermore, by placing the working vessel 21 in the thermal insulation tank 20, heat input from the outside to the process fluid in the working vessel 21 can be prevented.

[0043] In this embodiment, when the actuator 35 moves the magnet 23 in the vertical direction, the magnet holder 31 is guided by the linear guide 36, which prevents the magnet holder 31 and the magnet 23 from shaking side to side and allows them to move smoothly in the vertical direction. Furthermore, by installing the actuator 35 outside the thermal insulation tank 20, heat input from the actuator 35 into the thermal insulation tank 20 and, further, heat input into the process fluid in the working vessel 21 can be prevented.

[0044] Furthermore, in this embodiment, the magnet holder 31 that holds the magnet 23 via the eccentricity misalignment absorbing part 37 is attached to the tip of the rod 35a of the actuator 35. This allows the rod 35a of the actuator 35 to smoothly extend and retract even if the magnet holder 31 is slightly tilted when the magnet 23 is moved back and forth in the vertical direction. Therefore, the magnet holder 31 and the magnet 23 held thereby can be moved back and forth smoothly in the vertical direction.

[0045] In addition, this embodiment is provided with a circulation line 8 consisting of a heat exhaust line 5 and a return line 6. As a result, the process fluid is used as a medium for carrying out the heat from the magnetic working material 22, and this process fluid flows through the circulation line 8 and can be reused.

[0046] The magnet moving structure 30 exemplified in this embodiment is configured to excite the magnetic working material 22 by raising the magnet 23 and to demagnetize the magnetic working material 22 by lowering the magnet 23. However, the magnet moving structure 30 may be configured to excite the magnetic working material 22 by lowering the magnet 23 and to demagnetize the magnetic working material 22 by raising the magnet 23. In either case, the configuration of the magnet moving structure 30 can be changed as appropriate.

[0047] In the above embodiment, the magnet 23 is configured to reciprocate in the vertical direction, but this is not limiting. For example, in FIG. 2 , the entire magnetic refrigerator 2 may be tilted by a predetermined angle in the direction of the arrow b. For example, if it is tilted by 90 degrees, the magnet 23 is configured to reciprocate in the horizontal direction. In other words, it is sufficient that the magnet 23 is configured to reciprocate in a predetermined direction relative to the fixed working vessel 21. Therefore, all references to the "vertical direction" in the description of the above embodiment can be replaced with the "predetermined direction."

[0048] In the above embodiment, the magnet 23 has a cylindrical shape having the internal space 23S, but this is not limiting. The magnet 23 only needs to surround the side surface of the working container 21 when the working container 21 is inserted into the magnet 23.

[0049] In the above embodiment, a vacuum chamber is used as the heat insulating chamber 20, but the invention is not limited to this and any structure that can provide heat insulation from the outside may be used.

[0050] In the above embodiment, the process fluid to be cooled that flows into the working vessel 21 is a liquid fluid, but it may also be a gaseous fluid.

[0051] From the above description, many modifications and other embodiments of the present disclosure will be apparent to those skilled in the art. Therefore, the above description should be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best mode for carrying out the present disclosure. Details of the structure and / or function thereof can be substantially changed without departing from the spirit of the present disclosure.

[0052] (Summary of the present disclosure) A magnetic refrigerator according to a first aspect of the present disclosure comprises an insulated tank, a working vessel fixed within the insulated tank, having an inlet and an outlet for a process fluid, and filled with the process fluid, a magnetic working material installed within the working vessel and in direct contact with the process fluid, which generates heat when excited and absorbs heat when demagnetized, a magnetic field generating device arranged within the insulated tank and which surrounds the side of the working vessel when the working vessel is advanced therethrough, and a magnetic field generating device moving structure which moves the magnetic field generating device back and forth in a predetermined direction within the insulated tank, thereby moving the working vessel into the magnetic field generating device to magnetize the magnetic working material, and moving the working vessel out of the magnetic field generating device to demagnetize the magnetic working material.

[0053] According to this configuration, the magnetic field generator is moved back and forth in a predetermined direction to magnetize and demagnetize the magnetic working material in the working vessel. The working vessel, which is filled with the process fluid, is fixed, and the magnetic working material installed in the working vessel is not moved. This reduces the risk of the process fluid leaking from the working vessel. Furthermore, since there is no driving device for moving the magnetic working material, heat input from the driving device to the process fluid in the working vessel can be prevented. Furthermore, by placing the working vessel in a thermally insulated tank, heat input from the outside to the process fluid in the working vessel can be prevented.

[0054] A magnetic refrigerator according to a second aspect of the present disclosure may be the magnetic refrigerator according to the first aspect, wherein the magnetic field generating device movement structure includes an actuator that moves the magnetic field generating device back and forth, and a linear guide that guides the back and forth movement of the magnetic field generating device.

[0055] According to this configuration, when the magnetic field generating device is moved back and forth by the actuator, the magnetic field generating device is guided by a linear guide, thereby preventing lateral shaking and allowing the magnetic field generating device to move smoothly in a specified direction.

[0056] A magnetic refrigerator according to a third aspect of the present disclosure may be the magnetic refrigerator according to the second aspect, wherein the actuator includes a rod that expands and contracts in the predetermined direction, and the magnetic field generating device is connected to a tip of the rod via an eccentricity / angle absorbing component.

[0057] According to this configuration, the magnetic field generator is attached to the tip of the actuator rod via an eccentricity / angle absorbing component. This allows the actuator rod to smoothly extend and retract even if the magnetic field generator is slightly tilted when it is moved back and forth in a predetermined direction. This allows the magnetic field generator to smoothly move back and forth in a predetermined direction.

[0058] A magnetic refrigerator according to a fourth aspect of the present disclosure is the magnetic refrigerator according to the third aspect, wherein the eccentricity misalignment absorbing component may include a floating joint.

[0059] A magnetic refrigerator according to a fifth aspect of the present disclosure is the magnetic refrigerator according to any one of the first to fourth aspects, wherein the heat-insulating vessel may include a vacuum vessel.

[0060] A magnetic refrigerator according to a sixth aspect of the present disclosure may be the magnetic refrigerator according to the third aspect, wherein the thermally insulated tank includes a vacuum tank, the rod of the actuator is arranged to pass through the vacuum tank, and the magnetic refrigerator includes a high-pressure difference resistant seal arranged in a portion of the vacuum tank through which the rod passes.

[0061] This allows the vacuum state inside the vacuum chamber to be maintained in a good condition. In addition, in this case, by installing the actuator body outside the thermal insulation chamber made of the vacuum chamber, heat input from the actuator into the thermal insulation chamber and further into the process fluid inside the working vessel can be prevented.

[0062] A magnetic refrigerator according to a seventh aspect of the present disclosure is the magnetic refrigerator according to the sixth aspect, wherein the high pressure difference compatible seal may include a bellows seal.

[0063] A magnetic refrigerator according to an eighth aspect of the present disclosure is the magnetic refrigerator according to any one of the first to seventh aspects, wherein the magnetic field generating device may include a permanent magnet.

[0064] A magnetic refrigerator according to a ninth aspect of the present disclosure is the magnetic refrigerator according to any one of the first to seventh aspects, wherein the magnetic field generating device may include an electromagnet.

[0065] A magnetic refrigerator according to a tenth aspect of the present disclosure is the magnetic refrigerator according to any one of the second to fourth aspects, wherein the actuator may include a hydraulic or pneumatic actuator. For example, the actuator may include a hydraulic cylinder, a pneumatic cylinder, or the like.

[0066] A magnetic refrigerator according to an eleventh aspect of the present disclosure is the magnetic refrigerator according to any one of the second to fourth aspects, wherein the actuator includes an electric actuator. For example, the actuator may include an electric cylinder.

[0067] A magnetic refrigerator according to a twelfth aspect of the present disclosure is the magnetic refrigerator according to any one of the first to eleventh aspects, wherein the inlet includes a first inlet connected to a feed line that supplies the process fluid to the working vessel and a second inlet connected to a first end of a circulation line, the outlet includes a first outlet connected to a cold discharge line through which the process fluid discharged from the working vessel flows and a second outlet connected to a second end of the circulation line, the circulation line has a cooler that cools the process fluid discharged from the second outlet, and the magnetic field generating device moving structure In a state where the magnetic field generating device is moved by a magnetic field generating device moving structure to excite the magnetic working material, the process fluid is supplied from the circulation line to the second inlet, and the process fluid, which has been heated by the heat generated by the magnetic working material, is discharged from the second outlet to the circulation line; and in a state where the magnetic field generating device is moved by the magnetic field generating device moving structure to demagnetize the magnetic working material, the process fluid is supplied from the feed line to the working vessel, and the process fluid, which has been cooled by the heat absorbed by the magnetic working material, is discharged from the first outlet to the cold discharge line.

[0068] According to this configuration, the process fluid is used as a medium for carrying out heat from the magnetic working material, and this process fluid can be reused by flowing through the circulation line.

[0069] 2 Magnetic refrigerator 3 Feed line 4 Cold discharge line 5 Heat exhaust line 6 Return line 8 Circulation line 20 Heat insulation tank 21 Working vessel 22 Magnetic working material 23 Magnetic field generator 30 Magnetic field generator movement structure 35 Actuator 36 Linear guide 37 Eccentricity misalignment absorbing part 49 High pressure difference compatible seal 51 Cooler 52 Buffer tank

Claims

1. A magnetic refrigerator comprising: an insulated tank; a working vessel fixed within the insulated tank, having an inlet and outlet for a process fluid, and filled with the process fluid; a magnetic working material installed within the working vessel and in direct contact with the process fluid, which generates heat when excited and absorbs heat when demagnetized; a magnetic field generator arranged within the insulated tank and which surrounds the side of the working vessel when the working vessel is advanced; and a magnetic field generator movement structure which moves the magnetic field generator back and forth in a predetermined direction within the insulated tank, thereby moving the working vessel into the magnetic field generator to magnetize the magnetic working material and moving the working vessel out of the magnetic field generator to demagnetize the magnetic working material.

2. The magnetic refrigerator according to claim 1, wherein the magnetic field generating device movement structure comprises: an actuator that moves the magnetic field generating device back and forth; and a linear guide that guides the back and forth movement of the magnetic field generating device.

3. The magnetic refrigerator according to claim 2, wherein the actuator comprises a rod that expands and contracts in the predetermined direction, and the magnetic field generator is connected to the tip of the rod via an eccentricity / angle absorbing part.

4. The magnetic refrigerator according to claim 3, wherein the eccentricity and angular misalignment absorbing component includes a floating joint.

5. The magnetic refrigerator according to claim 1, wherein the heat insulating vessel includes a vacuum vessel.

6. The magnetic refrigerator according to claim 3, wherein the thermal insulation vessel includes a vacuum vessel, the rod of the actuator is arranged to pass through the vacuum vessel, and the magnetic refrigerator is provided with a high pressure difference compatible seal arranged at the portion of the vacuum vessel through which the rod passes.

7. The magnetic refrigerator according to claim 6, wherein the high pressure differential seal includes a bellows seal.

8. The magnetic refrigerator according to claim 1, wherein the magnetic field generating device includes a permanent magnet.

9. The magnetic refrigerator according to claim 1, wherein the magnetic field generating device includes an electromagnet.

10. The magnetic refrigerator according to claim 2, wherein the actuator comprises a hydraulic or pneumatic actuator.

11. The magnetic refrigerator according to claim 2, wherein the actuator includes an electric actuator.

12. The inlet includes a first inlet connected to a feed line that supplies the process fluid to the working vessel and a second inlet connected to a first end of a circulation line, the outlet includes a first outlet connected to a cold discharge line through which the process fluid discharged from the working vessel flows and a second outlet connected to a second end of the circulation line, the circulation line has a cooler that cools the process fluid discharged from the second outlet, the magnetic field generator is moved by the magnetic field generator moving structure to excite the magnetic working material, the process fluid is supplied from the circulation line to the second inlet, and the process fluid heated by the heat generated by the magnetic working material is discharged from the second outlet to the circulation line, the magnetic field generator is moved by the magnetic field generator moving structure to demagnetize the magnetic working material, the process fluid is supplied from the feed line to the working vessel, and the process fluid cooled by the heat absorption of the magnetic working material is discharged from the first outlet to the cold discharge line.

12. The magnetic refrigerator according to claim 1.

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