Bed structure and method for manufacturing bed structure

Abstract

This bed structure (10) is used in a magnetic refrigeration system through which a fluid passes in a first direction. A plurality of particles having a magnetocaloric effect are arranged in the first direction and a second direction crossing the first direction. The plurality of particles are adhered to each other with an adhesive so that a flow path (30) through which the fluid passes is formed between the plurality of particles. The density of the particles in the first direction is greater than the density of the particles in the second direction.

Description

Bed structure and method for manufacturing the bed structure

[0001] The present invention relates to a bed structure and a method for manufacturing the bed structure.

[0002] Active magnetic regenerator (AMR) magnetic refrigeration systems have been known as an environmentally friendly refrigeration technology. As disclosed in Patent Document 1 (JP 2020-46085 A), AMR magnetic refrigeration systems have a bed structure including a plurality of frame bodies and a plurality of mesh bodies. The plurality of frame bodies each contain a magnetic working material and are stacked on top of each other. The plurality of mesh bodies are provided between the plurality of frame bodies and face the magnetic working material.

[0003] However, in the technology disclosed in Patent Document 1, the magnetic working material housed in one frame is of a different type from the magnetic working material housed in another frame, and therefore, in a bed structure using multiple types of magnetic working material, mesh bodies corresponding to the types are required.

[0004] A bed structure according to a first aspect is a bed structure used in a magnetic refrigeration system in which a fluid passes in a first direction. A plurality of particles having a magnetocaloric effect are arranged in the first direction and a second direction intersecting the first direction. The plurality of particles are bonded to each other with an adhesive so that a flow path through which the fluid passes is formed between the plurality of particles. The density of the particles in the first direction is greater than the density of the particles in the second direction.

[0005] The bed structure of the first aspect can be realized by providing a membrane with a reduced thickness, in which the density of particles in the first direction is greater than the density of particles in the second direction due to the particles arranged in the second direction being pushed in the first direction. Therefore, in the bed structure of the first aspect, even when a fluid passes through the flow path, the movement of particles in the first direction can be suppressed. Therefore, the bed structure of the first aspect can omit the mesh body that suppresses the movement of particles in the first direction.

[0006] A bed structure according to a second aspect is the bed structure according to the first aspect, wherein the plurality of particles have the same phase transition temperature.

[0007] Like the bed structure of the second aspect, it may comprise a plurality of particles having the same phase transition temperature.

[0008] A bed structure according to a third aspect is the bed structure according to the first aspect, wherein the plurality of particles have a plurality of phase transition temperatures.

[0009] Like the bed structure of the third aspect, it may comprise a plurality of particles having a plurality of phase transition temperatures.

[0010] A bed structure according to a fourth aspect is the bed structure according to the third aspect, wherein the plurality of particles have a plurality of phase transition temperatures in a first direction and the same phase transition temperature in a second direction.

[0011] In the bed structure of the fourth aspect, even if the bed structure has a cascade structure, it is possible to omit mesh members corresponding to different phase transition temperatures.

[0012] A bed structure according to a fifth aspect is the bed structure according to any one of the first aspect to the fourth aspect, wherein the maximum diameter of the plurality of particles is 50 μm or more and 250 μm or less.

[0013] As in the bed structure of the fifth aspect, a plurality of particles having a maximum diameter of 50 μm or more and 250 μm or less may be provided.

[0014] A bed structure according to a sixth aspect is the bed structure according to any one of the first aspect to the fifth aspect, wherein the average porosity is 40% or more.

[0015] In the bed structure of the sixth aspect, the average porosity is 40% or more, so that a wide fluid flow path can be secured.

[0016] A manufacturing method of a bed structure according to a seventh aspect is a manufacturing method of a bed structure used in a magnetic refrigeration system, and includes the following steps: forming a first film including a plurality of first particles and an adhesive; the plurality of first particles having a magnetocaloric effect; pressing the first film to reduce the thickness of the first film; forming a second film including a plurality of second particles and an adhesive on the reduced thickness first film; the plurality of second particles having a magnetocaloric effect.

[0017] In the bed structure manufacturing method of the seventh aspect, a first film including a plurality of first particles and an adhesive arranged in a second direction is pressed in a first direction, thereby suppressing the movement of the first particles in the first direction. Therefore, a first film (hereinafter also referred to as a "thin film" or a "first thin film") having a reduced thickness can be formed, which makes it possible to omit a mesh body that suppresses the movement of the first particles in the first direction. By stacking a second film including second particles on such a thin film, a plurality of particles are stacked in the first direction, making it possible to manufacture a bed structure in which a mesh body can be omitted.

[0018] A method for manufacturing a bed structure according to an eighth aspect is a method for manufacturing a bed structure according to the seventh aspect, in which the step of forming the first film includes a step of arranging a plurality of first particles and a step of arranging an adhesive between the plurality of first particles.

[0019] In the eighth aspect of the bed structure manufacturing method, the particle filling rate can be improved by pressing a first film with adhesive between a plurality of first particles arranged in the second direction.

[0020] A manufacturing method of a bed structure according to a ninth aspect is the manufacturing method of a bed structure according to the seventh aspect, in which the step of forming the first film includes the steps of arranging a plurality of first particles, arranging an adhesive between the plurality of first particles, and arranging a plurality of third particles on the plurality of first particles after the step of arranging the adhesive. The plurality of third particles have a magnetocaloric effect.

[0021] In the method for manufacturing a bed structure of the ninth aspect, the first film having the third particles arranged on top of the first particles and adhesive is pressed, so that a thin film that maintains gaps between the particles can be easily manufactured.

[0022] A manufacturing method of a bed structure according to a tenth aspect is the manufacturing method of a bed structure according to the seventh or eighth aspect, wherein the thickness of the thinned first film is not more than twice the maximum thickness of the first particles.

[0023] In the manufacturing method of the bed structure of the tenth aspect, it is possible to form a thin film in which the first particles are prevented from overlapping in the first direction.

[0024] A method for manufacturing a bed structure according to an eleventh aspect is the method for manufacturing a bed structure according to any one of the seventh aspect to the tenth aspect, wherein the maximum diameter of the first particles is 50 μm or more and 250 μm or less.

[0025] As in the method for manufacturing a bed structure according to the eleventh aspect, a bed structure including first particles having a maximum diameter of 50 μm or more and 250 μm or less may be manufactured.

[0026] A method for manufacturing a bed structure according to a twelfth aspect is a method for manufacturing a bed structure according to any one of the seventh aspect to the eleventh aspect, in which the phase transition temperature of the first particles is the same as the phase transition temperature of the second particles.

[0027] As in the method for producing a bed structure according to the twelfth aspect, a bed structure including a plurality of particles having the same phase transition temperature may be produced.

[0028] A method for manufacturing a bed structure according to a thirteenth aspect is the method for manufacturing a bed structure according to any one of the seventh aspect to the eleventh aspect, in which the phase transition temperature of the first particles is different from the phase transition temperature of the second particles.

[0029] As in the method for manufacturing a bed structure according to the thirteenth aspect, a bed structure including a plurality of particles having a plurality of phase transition temperatures may be manufactured.

[0030] A manufacturing method of a bed structure according to a fourteenth aspect is a manufacturing method of a bed structure according to any one of the seventh aspect to the thirteenth aspect, in which the first film forming step and the second film forming step form the first film and the second film in a container.

[0031] As in the method for manufacturing a bed structure according to the fourteenth aspect, the first and second membranes may be formed using a container.

[0032] A bed structure manufacturing method according to a fifteenth aspect is the bed structure manufacturing method according to the fourteenth aspect, further comprising the step of removing the container.

[0033] As in the method for manufacturing a bed structure according to the fifteenth aspect, a container may be used to form the first and second films, and then the container may be removed.

[0034] A method for manufacturing a bed structure according to a sixteenth aspect is a method for manufacturing a bed structure according to any one of the seventh aspect to the fifteenth aspect, further comprising a step of confirming that a flow path through which a fluid passes is formed.

[0035] In the method for manufacturing a bed structure according to the sixteenth aspect, it is confirmed that flow paths through which a fluid passes are formed between particles, so that a bed structure in which flow paths are reliably formed can be manufactured.

[0036] FIG. 1 is a schematic diagram of a bed structure according to an embodiment of the present disclosure. FIG. 1 is a schematic diagram of a first layer constituting the bed structure. FIG. 2 is a flowchart showing a method for manufacturing the bed structure. FIG. 2 is a perspective view showing a container. FIG. 3 is a schematic cross-sectional view showing a state after a first film has been formed. FIG. 4 is a schematic cross-sectional view showing a step of arranging first particles. FIG. 5 is a schematic cross-sectional view showing a step of spraying an adhesive. FIG. 6 is a schematic cross-sectional view showing a pushing step. FIG. 7 is a cross-sectional view showing a state after a second film has been formed. FIG. 8 is a cross-sectional view showing a state after a first layer has been formed. FIG. 9 is a schematic diagram of a heat source according to an embodiment of the present disclosure. FIG. 10 is a schematic diagram of a magnetic refrigeration system according to an embodiment of the present disclosure. FIG. 11 is a flowchart showing a method for manufacturing a bed structure according to a modified example. FIG. 12 is a flowchart showing a method for manufacturing a bed structure according to another modified example. FIG. 13 is a schematic cross-sectional view showing a state after a first film has been formed according to another modified example. FIG. 14 is a schematic cross-sectional view showing a pushing step according to another modified example.

[0037] Hereinafter, a bed structure, a heat source, and a magnetic refrigeration system according to an embodiment of the present disclosure will be described with reference to examples.

[0038] (1) Bed Structure (1-1) Overview The bed structure 10 shown in FIG. 1 is used in an active magnetic regenerator (AMR) type magnetic refrigeration system. The bed structure 10 is used in a magnetic refrigeration system in which a fluid passes in a first direction. Such a bed structure 10 includes a plurality of particles and an adhesive. The particles are arranged in the first direction and a second direction intersecting the first direction. In FIGS. 1 and 2, the first direction is the vertical direction, and the second direction is perpendicular to the first direction. Here, the first direction is the stacking direction of layers L1 to L5, and the second direction is the extension direction of the plane on which the particles are laid out. Flow paths 30 through which the fluid passes are formed between the particles.

[0039] Such a bed structure 10 has at least two layers arranged side by side. The shapes and arrangement of the layers constituting the bed structure 10 are not particularly limited. In this embodiment, as shown in FIG. 1, the bed structure 10 includes a first layer L1, a second layer L2, a third layer L3, a fourth layer L4, and a fifth layer L5. The multiple layers L1 to L5 extend in a first direction and a second direction and are stacked in the first direction. There is no mesh between the layers L1 to L5 to separate them. The flow paths 30 of the layers L1 to L5 are connected.

[0040] Each of the layers L1 to L5 includes a plurality of thin films F1 to F6. The thin films F1 to F6 are films that extend in the second direction and are stacked in the first direction. The thin films F1 to F6 include a plurality of particles and an adhesive.

[0041] The thin films F1 to F6 of the first layer L1 will be described with reference to Figure 2. The first thin film F1 includes a plurality of first particles 1 and an adhesive 20. The second thin film F2 includes a plurality of second particles 2 and an adhesive 20. The third thin film F3 includes a plurality of third particles 3 and an adhesive 20. The fourth thin film F4 includes a plurality of fourth particles 4 and an adhesive 20. The fifth thin film F5 includes a plurality of fifth particles 5 and an adhesive 20. The sixth thin film F6 includes a plurality of sixth particles 6 and an adhesive 20.

[0042] Particles 1 to 6 can be used to cool or heat an object whose temperature is to be regulated by obtaining a magnetocaloric effect by changing the magnetic entropy. Particles 1 to 6 generate heat when a magnetic field is applied, and absorb heat when the application of the magnetic field is stopped and the magnetic field is removed.

[0043] The particles 1 to 6 are not limited as long as they have a magnetocaloric effect. Here, the particles 1 to 6 are magnetic working materials having a Curie temperature, which is a phase transition temperature. Examples of such particles 1 to 6 include NaZn １３ Materials with the structure (La-Fe-Si based materials), MnAs １－ｘ Sb ｘ Examples include:

[0044] Particles 1 to 6 are fine particles. In this embodiment, particles 1 to 6 are particles that have been pulverized by applying mechanical (mechanical) energy. The maximum diameter of particles 1 to 6 is, for example, 50 μm or more and 250 μm or less. The maximum diameter is measured by a laser diffraction method, an optical microscope, or the like.

[0045] The thickness of each of the first thin film F1 to sixth thin film F6 is not more than twice the maximum diameter of the particles 1 to 6. Therefore, the thickness of each of the first thin film F1 to sixth thin film F6 is not less than 50 μm and not more than 500 μm.

[0046] In this embodiment, the particles 1 to 6 constituting the first thin film F1 to the sixth thin film F6 are arranged so as not to overlap in the second direction, and therefore, the thickness of each of the first thin film F1 to the sixth thin film F6 in this embodiment is 50 μm or more and 250 μm or less.

[0047] In the first thin film F1 to the sixth thin film F6, one end in the first direction (upper end in FIG. 2) of the particles 1 to 6 aligned in the second direction is aligned in the second direction.

[0048] The first to sixth particles 1 to 6 of this embodiment have the same phase transition temperature. Note that the same phase transition temperature means that the phase transition temperature is within, for example, 0.5°C, including manufacturing tolerances, and for higher precision, the phase transition temperature is within, for example, 0.2°C.

[0049] The adhesive 20 bonds the plurality of particles 1 to 6 to one another so that flow paths 30 through which a fluid passes are formed between the plurality of particles 1 to 6. Here, the adhesive 20 comes into contact with a portion of the surface of the particles 1 to 6. Note that the adhesive 20 may bond adjacent particles to one another in the second direction, or may bond adjacent particles to one another in the first direction.

[0050] The adhesive 20 has a thermal conductivity lower than that of the particles 1 to 6. The adhesive 20 has, for example, insulating properties and is an inorganic adhesive or an organic adhesive. For example, epoxy resin, acrylic resin, or the like can be used as the adhesive 20.

[0051] The adhesive 20 contained in each of the thin films F1 to F6 may be the same or different.

[0052] Gaps are provided between the particles 1 to 6 that are bonded together, and these gaps form flow paths 30 through which a fluid passes. Because a portion of the surface of the particles 1 to 6 is exposed, the fluid passing through the flow paths 30 exchanges heat with the particles 1 to 6.

[0053] The layers L2 to L5 of this embodiment have basically the same structure as the layer L1, but the magnetocaloric effects of the particles contained therein are different. In other words, the particles constituting the layers L1 to L5 are different from one another. In other words, the bed structure 10 contains multiple types of particles.

[0054] With the above configuration, the particles of the bed structure 10 have multiple phase transition temperatures in the first direction and the same phase transition temperature in the second direction. Specifically, the particles of the first layer L1 are made of materials with decreasing phase transition temperatures, in order of decreasing phase transition temperatures, the particles of the second layer L2, the particles of the third layer L3, the particles of the fourth layer L4, and the particles of the fifth layer L5. In other words, the particles of the first layer L1, the particles of the second layer L2, the particles of the third layer L3, the particles of the fourth layer L4, and the particles of the fifth layer L5 are arranged in order of decreasing phase transition temperatures.

[0055] In the first layer L1, the density of the particles 1 to 6 in the first direction is greater than the density of the particles 1 to 6 in the second direction. In this embodiment, the density of the particles 1 to 6 in the first direction is, for example, 1.1 times or more, and preferably 1.3 times or more, the density of the particles 1 to 6 in the second direction.

[0056] Similarly, in each of the second layer L2 to the fifth layer L5, the particle density in the first direction is greater than the particle density in the second direction. Therefore, in the bed structure 10, the particle density in the first direction is also greater than the particle density in the second direction, for example, 1.1 times or more, and preferably 1.3 times or more, of the particle density in the second direction.

[0057] The particle density in the first direction is the density of a line along the first direction, and the particle density in the second direction is the density of a line along the second direction. In other words, the particle density in the first direction is the particle occupancy ratio density in the first direction, and the particle density in the second direction is the particle occupancy ratio in the second direction. The densities are determined as the area ratio by observing cross sections in the first and second directions with an optical microscope.

[0058] The average porosity of the bed structure 10 of this embodiment is 40% or more. The average porosity is determined by an optical method, which is determined by microscopic observation from the area of ​​the particles and adhesive and the area of ​​visible voids. Alternatively, if the proportion of adhesive 20 is ignored or assumed, the average porosity can be calculated from the volume and weight of the bed structure 10.

[0059] Such average void ratio can be adjusted in the manufacturing method of the bed structure 10 described below by controlling the pressing force in the first direction in the pressing step (S3, S5), controlling the amount of particles to be laid in the arranging step (S22), controlling the amount of adhesive, etc.

[0060] Furthermore, the bed structure 10 does not include a mesh between each of the layers L1 to L5 to separate different types of particles. Therefore, particles of different compositions are connected in the first direction via the adhesive 20. Specifically, particles located at one end of the first layer L1 in the first direction (the upper end in FIG. 1 ) and particles located at the other end of the second layer L2 in the first direction (the lower end in FIG. 1 ) are connected via the adhesive 20. Particles located at one end of the second layer L2 and particles located at the other end of the third layer L3 are connected via the adhesive 20. Particles located at one end of the third layer L3 and particles located at the other end of the fourth layer L4 are connected via the adhesive 20. Particles located at one end of the fourth layer L4 and particles located at the other end of the fifth layer L5 are connected via the adhesive 20.

[0061] (1-2) Manufacturing Method Hereinafter, a method for manufacturing the bed structure 10 shown in Fig. 1 will be described with reference to Figs. 1 to 10. In this specification, the thin films F1 to F6 containing the uncured adhesive 20 and the thin films F1 to F6 containing the cured adhesive 20 will be described using the same name.

[0062] First, a method for manufacturing the first layer L1 shown in Fig. 2 will be described. First, as shown in Figs. 3 and 4, a container 40 is prepared (step S1). The container 40 used in step S1 is configured with a surface that is open on one side in a first direction (upward in Fig. 4). In Fig. 4, the container 40 has a bottom surface 41 and four side surfaces 42 extending upward from the bottom surface 41. The bottom surface 41 and the side surfaces 42 are, for example, mesh filters. The mesh filter has a plurality of pores smaller than the particles.

[0063] Next, as shown in Fig. 5, a first film F11 including a plurality of first particles 1 and an adhesive 20 is formed (step S2). The plurality of first particles 1 have the same phase transition temperature. The thickness of the first film F11 is not limited as long as it is in a film form. Step S2 of forming the first film F11 of this embodiment involves, for example, the following steps.

[0064] Specifically, first particles 1 are prepared (step S21). Here, the first particles 1 are prepared by classifying them into particles having a maximum diameter of 50 μm or more and 250 μm or less using a sieve.

[0065] Then, as shown in FIG. 6 , a plurality of first particles 1 are arranged (step S22). Here, a plurality of first particles 1 are arranged in the second direction on the bottom surface 41 of the container 40. Specifically, the plurality of first particles 1 are spread across the entire bottom surface 41 so as to be aligned in the second direction. In other words, the plurality of first particles 1 are spread across the entire bottom surface 41 so as not to overlap in the first direction. To spread the first particles 1 in the second direction, for example, a slit-shaped jig that moves at a constant speed is used. Note that, for convenience, each particle 1 is shown with the same shape in FIG. 6 ; however, in this embodiment, crushed particles are used as the first particles 1, and therefore, the heights in the first direction are not uniform.

[0066] Next, as shown in Fig. 7, adhesive 20 is placed between the plurality of first particles 1 (step S23). Here, as shown in Fig. 7, a spraying member 43 filled with adhesive 20 is placed above container 40 so as to face bottom surface 41, and adhesive 20 is sprayed from this spraying member 43. The adhesive 20 may or may not be in contact with the first particles 1. Here, at least a portion of the adhesive 20 contacts a portion of the outer surface of the first particles 1.

[0067] In step S23, an appropriate amount of adhesive 20 is placed. The appropriate amount is an amount that will ensure a flow path 30 through which a fluid passes when the bed structure 10 is formed. If more than the appropriate amount of adhesive 20 is placed, a step of removing the excess adhesive 20 is carried out. In this step, it is determined, for example, by visual inspection whether or not excess adhesive 20 has been placed. If it is determined that excess adhesive has been placed, air is blown onto the adhesive 20 to blow off the excess adhesive 20.

[0068] Thereafter, the adhesive 20 is cured to a certain extent (step S24). Here, the adhesive 20 is cured (semi-cured) by heat treatment or the like until the adhesiveness of the adhesive 20 remains. This allows the adhesive 20 and the first particles 1 to be connected to a certain extent.

[0069] Next, as shown in FIG. 8 , the first film F11 is pressed to reduce its thickness (step S3). More specifically, the first film F11 extending in the second direction is pressed in the first direction. Here, a pressing member 45 is used to press one end of the first particle 1 in the first direction (the upper end in FIG. 8 ) downward from above the first film F11. The pressing member 45 has a flat portion 45a that presses against the first film F11. The flat portion 45a contacts one end of the first particle 1 in the first direction. By performing this step S3, a first thin film F1 (see FIG. 9 ) having a thickness thinner than the thickness of the first film F11 in the first direction in step S2 can be formed. This first thin film F1 is in a semi-cured state of the adhesive 20 in FIG. 2 .

[0070] The thickness of the first film F11 of the first thin film F1 may be reduced by deforming the first particles 1, but here, the thickness of the first film F11 is reduced by aligning the orientation of the first particles 1 and reducing the gaps between the particles 1 without deforming the first particles 1.

[0071] Furthermore, by performing the pushing step (S3), it is possible to form the first thin film F1 with an increased density of the first particles 1 of the first film F11. Furthermore, it is possible to form the first thin film F1 with an increased flatness by aligning one end of the first particles 1 of the first film F11 in the first direction.

[0072] The thickness of the first thin film F1 is not more than twice the maximum thickness of the first particles 1. Therefore, the first thin film F1 is formed to be 50 μm or more and 500 μm or less. Here, the first particles 1 are arranged so as not to overlap in the second direction, so the thickness of the first thin film F1 formed by the pressing step (S3) is 50 μm or more and 250 μm or less.

[0073] 9, a second film F12 including second particles 2 and an adhesive 20 is formed on the first thin film F1 (step S4). In step S4, similar to the pressing step (S3), a plurality of second particles 2 are arranged on the first thin film F1 in the second direction, and then the adhesive 20 is arranged between the plurality of second particles 2.

[0074] Next, the second film F12 is pressed to reduce the thickness of the second film F12 (step S5). This step S5 is similar to the step (S3) of pressing the first film F11. This step S5 allows the second thin film F2 to be formed.

[0075] Similarly, the third to sixth thin films F3 to F6 are formed in sequence (steps S6 to S9). As a result, a first laminated structure can be formed in which a plurality of thin films F1 to F6 are laminated in the first direction, as shown in Fig. 10. The first laminated structure is a first layer L1 in which the adhesive 20 is in a semi-cured state.

[0076] Next, a second laminate structure (step S10) that will become the second layer L2 is formed using particles having a phase transition temperature higher than that of the particles 1 to 6 that make up the first layer L1, similar to the step of forming the first laminate structure (steps S1 to S9). Next, a third laminate structure (step S11) that will become the third layer L3 is formed using particles having a phase transition temperature higher than that of the particles that make up the second layer L2, similar to the step of forming the first laminate structure (steps S1 to S9). Next, a fourth laminate structure (step S12) that will become the fourth layer L4 is formed using particles having a phase transition temperature higher than that of the particles that make up the third layer L3, similar to the step of forming the first laminate structure (steps S1 to S9). Next, a fifth laminate structure (step S13) that will become the fifth layer L5 is formed using particles having a phase transition temperature higher than that of the particles that make up the fourth layer L4, similar to the step of forming the first laminate structure (steps S1 to S9).

[0077] Next, the adhesive 20 is hardened (step S14). This allows a plurality of particles to be connected by the adhesive 20. By performing the above steps (S1 to S14), the first to fifth layers L1 to L5 can be formed in the container 40.

[0078] The curing step (S14) may be performed multiple times. For example, the curing step (S14) may be performed after each pressing step or after forming one laminated structure.

[0079] Next, the container 40 is removed (step S15). By carrying out the above steps (S1 to S15), the bed structure 10 shown in FIG.

[0080] In this embodiment, a step (step S16) is further performed to confirm that the flow path 30 through which the fluid passes is formed in the bed structure 10 after the container 40 is removed. In this step S15, for example, the formation of the flow path 30 is confirmed by visual inspection or by passing air through the bed structure 10.

[0081] (1-3) Operation A fluid passes through the flow path 30 of the bed structure 10 of this embodiment. The fluid flows while exchanging heat with the exposed particles. At this time, when the particles generate heat due to the application of a magnetic field, or when the particles absorb heat due to the cessation of the application of a magnetic field, the fluid is heated or cooled by the particles.

[0082] (2) Heat Source The heat source of this embodiment utilizes heat emitted from the particles to exchange heat with the fluid. The heat source includes the bed structure described above in (1) and an application unit. Therefore, the heat source includes multiple types of particles with different magnetocaloric effects.

[0083] The application unit applies a magnetic field to the particles. Specifically, the application unit is capable of changing the magnetic field applied to the particles. The application unit has a magnetic circuit or the like, and has a portion located on one side and a portion located on the other side with respect to the plurality of types of particles.

[0084] The application unit can switch between a state in which a magnetic field is applied to the particles and a state in which a magnetic field is not applied to the particles. The application unit may also be capable of performing a process of strengthening the magnetic field applied to the particles and a process of weakening the magnetic field without reducing it to zero.

[0085] Such a heat source can be configured, for example, as a heat source 11 shown in Fig. 11. This heat source 11 includes a bed structure 10 and an application unit 31.

[0086] 11, the bed structure 10 has a plurality of layers L1 to L5 arranged side by side. The application unit 31 has a portion located on one side of the bed structure 10 and a portion located on the other side, and can apply a magnetic field to the bed structure 10, and can also stop applying the magnetic field to remove the magnetic field.

[0087] (3) Magnetic Refrigeration System The magnetic refrigeration system of this embodiment is an AMR system, and includes the heat source described in (2) above and a moving unit.

[0088] The moving part moves a fluid that exchanges heat with the particles. The fluid is in thermal contact with the particles. The fluid is, for example, a heat medium such as a refrigerant or water.

[0089] Specifically, the moving part moves the fluid relative to the plurality of types of particles contained in the bed structure. The moving part is not particularly limited, and may be composed of pistons provided on both sides of the particles, or may be composed of a pump provided in a closed circuit.

[0090] Such a magnetic refrigeration system can be configured, for example, as a magnetic refrigeration system 100 shown in Fig. 12. The magnetic refrigeration system 100 here is a temperature control device. The magnetic refrigeration system 100 includes a heat source 11, a transfer circuit 160, a high-temperature side circuit 140, and a low-temperature side circuit 150.

[0091] As described in (2) above, the heat source 11 has the bed structure 10 and the application unit 31. As described in (1) above, the bed structure 10 has a plurality of layers L1 to L5. The application unit 31 can apply a magnetic field to all of the particles in the bed structure 10, and can weaken or stop the applied magnetic field to remove the magnetic field.

[0092] The movement circuit 160 includes a tank 162, a pump 163, and a flow path 161 connecting these, and is filled with a fluid. The bed structure 10 may be disposed inside the tank 162, or may be disposed outside the tank 162 so that the fluid inside the tank 162 is in thermal contact with the particles. The tank 162 includes a high-temperature reservoir 162a on the high-temperature side relative to the bed structure 10 and a low-temperature reservoir 162b on the low-temperature side relative to the bed structure 10. In the bed structure 10, particles in the fifth layer L5, which have a high phase transition temperature, are located on the high-temperature reservoir 162a side, and particles in the first layer L1, which have a low phase transition temperature, are located on the low-temperature reservoir 162b side. When a magnetic field is applied to the bed structure 10 from the application unit 31 and the fluid is heated by heat radiated from the bed structure 10, the pump 163 is driven to move the fluid to the high-temperature side relative to the bed structure 10. As a result, the high-temperature fluid is stored in the high-temperature storage section 162a. Furthermore, when the application section 31 stops applying the magnetic field to the bed structure 10 and removes the magnetic field, the bed structure 10 absorbs heat from the fluid, and when the temperature of the fluid drops, the pump 163 is driven to move the fluid to the low-temperature side of the bed structure 10. As a result, the low-temperature fluid is stored in the low-temperature storage section 162b. By repeating the above-mentioned movement of the fluid and the application and removal of the magnetic field, the high-temperature fluid is collected in the high-temperature storage section 162a, and the low-temperature fluid is collected in the low-temperature storage section 162b.

[0093] The high-temperature side circuit 140 includes a high-temperature side first heat exchanger 141, a high-temperature side pump 144, a high-temperature side second heat exchanger 142, and a high-temperature side flow path 143 connecting these elements. A high-temperature side heat medium, such as a refrigerant or water, circulates through the circuit. The high-temperature side first heat exchanger 141 is disposed within the high-temperature reservoir 162a and performs heat exchange between the high-temperature side heat medium flowing through the high-temperature side first heat exchanger 141 and the high-temperature fluid in the high-temperature reservoir 162a. The high-temperature side second heat exchanger 142 heats a temperature-adjusted object by utilizing the high temperature of the high-temperature side heat medium flowing therethrough. The temperature-adjusted object may be air, a fluid such as water, or a solid object to be heated. The high-temperature side flow path 143 connects the high-temperature side first heat exchanger 141, the high-temperature side pump 144, and the high-temperature side second heat exchanger 142 so that the high-temperature side heat medium can circulate between them. The high-temperature side pump 144 circulates the high-temperature side heat medium in the high-temperature side circuit 140 when driven.

[0094] The low-temperature side circuit 150 includes a first low-temperature side heat exchanger 151, a low-temperature side pump 154, a second low-temperature side heat exchanger 152, and a low-temperature side flow path 153 connecting these elements. A low-temperature side heat medium, such as a refrigerant or water, circulates through the circuit. The first low-temperature side heat exchanger 151 is provided in a low-temperature reservoir 162b and performs heat exchange between the low-temperature side heat medium flowing through the first low-temperature side heat exchanger 151 and the low-temperature fluid in the low-temperature reservoir 162b. The second low-temperature side heat exchanger 152 uses the low temperature of the low-temperature side heat medium flowing through it to cool a temperature-adjusted object. The temperature-adjusted object may be air, a fluid such as water, or a solid to be cooled. The low-temperature side flow path 153 connects the first low-temperature side heat exchanger 151, the low-temperature side pump 154, and the second low-temperature side heat exchanger 152 so that the low-temperature side heat medium can circulate between them. When driven, the low-temperature side pump 154 ​​circulates the low-temperature side heat medium within the low-temperature side circuit 150 .

[0095] (4) Features (4-1) The bed structure 10 according to this embodiment is a bed structure used in a magnetic refrigeration system 100 in which a fluid passes in a first direction. A plurality of particles having a magnetocaloric effect are arranged in the first direction and a second direction intersecting the first direction. The plurality of particles are bonded to each other with an adhesive so that a flow path 30 through which the fluid passes is formed between the plurality of particles. The density of the particles in the first direction is greater than the density of the particles in the second direction.

[0096] By providing a thin film (thin films F1 to F6 in this embodiment) by pushing a plurality of particles arranged in the second direction in the first direction (pushing steps (S3, S5)), the bed structure 10 of this embodiment can be realized in which the density of particles in the first direction is greater than the density of particles in the second direction. Therefore, in the bed structure 10 of this embodiment, even if a fluid passes through the flow path 30, the movement of particles in the first direction can be suppressed. Therefore, in the bed structure 10 of this embodiment, it is possible to omit the mesh body that suppresses the movement of particles in the first direction.

[0097] When the bed structure 10 is used, cracks may occur in the particles due to wear and tear. Even in this case, the bed structure 10 of this embodiment can omit the mesh body, thereby preventing particles from clogging the mesh body and preventing fine particles from escaping from the mesh body. Furthermore, since adhesive can be prevented from clogging the mesh body, pressure loss can be reduced. Furthermore, since it is easy to confirm that the particles are connected, reliability can be improved.

[0098] (4-2) The bed structure 10 according to this embodiment is the bed structure according to (4-1) above, and the particles have a plurality of phase transition temperatures.

[0099] In this way, a plurality of particles having a plurality of phase transition temperatures may be provided.

[0100] (4-3) The bed structure 10 according to this embodiment is the bed structure according to (4-2) above, in which the particles have a plurality of phase transition temperatures in the first direction and the same phase transition temperature in the second direction.

[0101] Here, even if a cascade structure is provided, it is possible to omit the mesh members corresponding to different phase transition temperatures.

[0102] (4-4) The bed structure 10 according to this embodiment is the bed structure according to any one of the above (4-1) to (4-3), and the plurality of particles constituting the first layer L1 have the same phase transition temperature.

[0103] In this way, the first layer L1 may include a plurality of particles having the same phase transition temperature.

[0104] (4-5) The bed structure 10 according to this embodiment is the bed structure according to any one of the above (4-1) to (4-4), in which the maximum diameter of the plurality of particles is 50 μm or more and 250 μm or less.

[0105] In this way, a plurality of particles having a maximum diameter of 50 μm or more and 250 μm or less may be provided.

[0106] (4-6) The bed structure 10 according to this embodiment is the bed structure according to any one of the above (4-1) to (4-5), and has an average porosity of 40% or more.

[0107] Here, since the average porosity is 40% or more, a wide fluid flow path 30 can be ensured.

[0108] (4-7) The manufacturing method of the bed structure 10 according to this embodiment is a manufacturing method of a bed structure used in the magnetic refrigeration system 100, and includes the following steps: Forming a first film F11 including a plurality of first particles 1 and an adhesive 20 (Step S2). The plurality of first particles 1 have a magnetocaloric effect. Pressing the first film F11 to reduce the thickness of the first film F11 (Step S3). Forming a second film F12 including a plurality of second particles 2 and an adhesive 20 on the reduced thickness first film (first thin film F1) (Step S4). The plurality of second particles 2 have a magnetocaloric effect.

[0109] In the manufacturing method of the bed structure 10 of this embodiment, the first film F11 including the plurality of first particles 1 arranged in the second direction and the adhesive 20 is pushed in the first direction, thereby suppressing the movement of the first particles 1 in the first direction. Therefore, it is possible to form a first film (first thin film F1) having a reduced thickness, which makes it possible to omit a mesh body that suppresses the movement of the first particles 1 in the first direction. By stacking the second film F12 including the second particles 2 on such a first thin film F1, it is possible to manufacture a bed structure 10 in which a plurality of particles are stacked in the first direction and in which a mesh body can be omitted.

[0110] Furthermore, by carrying out the step (S3) of pressing during the lamination of the film, the adhesion of the particles can be made more reliable and the packing density of the particles can be increased.

[0111] (4-8) The manufacturing method of the bed structure 10 according to this embodiment is a manufacturing method of the bed structure according to (4-7) above, and the step (S2) of forming the first film F11 includes a step (S22) of arranging a plurality of first particles 1 and a step (S23) of arranging adhesive 20 between the plurality of first particles 1.

[0112] Here, the particle filling rate can be improved by the step (S3) of pressing the first film F11 with the adhesive 20 disposed between the plurality of first particles 1 disposed in the second direction.

[0113] (4-9) The manufacturing method of the bed structure 10 according to this embodiment is the manufacturing method of the bed structure according to the above (4-7) or (4-8), in which the thickness of the thinned first film (first thin film F1) is not more than twice the maximum thickness of the first particle 1.

[0114] Here, it is possible to form the first thin film F1 in which the first particles 1 are prevented from overlapping in the first direction.

[0115] (4-10) The manufacturing method for the bed structure 10 according to this embodiment is the manufacturing method for the bed structure according to any one of the above (4-7) to (4-9), in which the maximum diameter of the first particles is 50 μm or more and 250 μm or less.

[0116] In this way, a bed structure 10 may be produced comprising first particles 1 with a maximum diameter of 50 μm to 250 μm.

[0117] In this embodiment, a plurality of thin films F1 to F6 are formed using particles having a maximum diameter of 50 μm or more and 250 μm or less, and a plurality of layers L1 to L5 are formed by stacking the plurality of thin films F1 to F6, and the plurality of layers L1 to L5 are stacked to manufacture the bed structure 10.

[0118] (4-11) The manufacturing method of the bed structure 10 according to this embodiment is the manufacturing method of any one of the bed structures according to (4-7) to (4-10) above, in which the phase transition temperature of the first particles 1 is the same as the phase transition temperature of the second particles 2.

[0119] In this way, a bed structure 10 may be produced comprising thin films F1, F2 with a plurality of particles 1, 2 having the same phase transition temperature.

[0120] (4-12) The manufacturing method of the bed structure 10 according to this embodiment is a manufacturing method of the bed structure according to any one of (4-7) to (4-11) above, in which the phase transition temperature of the particles constituting the first layer L1 is different from the phase transition temperature of the particles constituting the second layer L2.

[0121] In this way, a bed structure 10 may be produced that comprises layers L1, L2 having multiple particles with multiple phase transition temperatures.

[0122] (4-13) The manufacturing method of the bed structure 10 according to this embodiment is a manufacturing method of a bed structure according to any one of (4-7) to (4-12) above, and in the step (S2) of forming the first film F11 and the step (S4) of forming the second film F12, the first film F11 and the second film F12 are formed in the container 40.

[0123] In this manner, the first film F11 and the second film F12 may be formed using the container 40.

[0124] (4-14) The method for manufacturing the bed structure 10 according to this embodiment is the method for manufacturing the bed structure according to (4-13) above, and further includes a step (S15) of removing the container 40.

[0125] In this way, after the first film F11 and the second film F12 are formed using the container 40, the container 40 may be removed. This allows the bed structure 10 to be manufactured without the container 40.

[0126] (4-15) The manufacturing method of the bed structure 10 according to this embodiment is a manufacturing method of the bed structure according to any one of (4-7) to (4-14) above, and further includes a step (S16) of confirming that a flow path 30 through which a fluid passes is formed.

[0127] Here, it is confirmed that flow paths 30 through which a fluid passes are formed between the particles, so that a bed structure 10 in which the flow paths 30 are reliably formed can be manufactured.

[0128] (5) Modifications (5-1) Modification 1 In the above embodiment, the step of pressing the first to sixth membranes F11 to F16 is performed after the step of forming the first to sixth membranes F11 to F16, but this is not limited to this. In the manufacturing method of the bed structure of the present disclosure, as long as at least one of the steps of pressing the first to sixth membranes is performed, the other pressing steps may be omitted. In other words, in the manufacturing method of the bed structure of the present disclosure, the membrane formed by repeating the steps of arranging particles, arranging adhesive, and curing the adhesive to a certain extent a predetermined number of times may be pressed. In this modification, for example, the first layer L1 is formed as follows.

[0129] Specifically, as shown in FIG. 13 , after the step (S4) of forming the second film F12, the third film F13 is formed (step S61) without performing the step (S5) of pressing the second film F12. Subsequently, the steps (S71) of forming the fourth film F14, (S81) of forming the fifth film F15, and (S91) of forming the sixth film F16 are sequentially performed. Next, the stacked second films F12 to F16 are pressed to form a thin film with a reduced total thickness of the second films F12 to F16 (step S92). By performing this step (S92), a thin film can be formed in which the first ends (top ends) of the multiple sixth particles located at one end (here, the upper end) of the sixth film F16 in the first direction are aligned. In this case, the thickness of the thin film formed on the first thin film F1 is greater than that of the first thin film F1.

[0130] In this way, the process of placing particles, placing adhesive, and hardening the adhesive to a certain extent is repeated a predetermined number of times to form a film, and the film is then pressed in a first direction to form a single thin film, thereby increasing the void ratio between the particles that form the flow path 30.

[0131] (5-2) Modification 2 In the above embodiment, the step (S2) of forming the first film includes the step (S22) of disposing the first particles 1 and the step (S23) of disposing the adhesive, but is not limited to this. In the manufacturing method of the bed structure disclosed herein, the number of times the step of disposing the particles is performed may be greater than the number of times the step of disposing the adhesive is performed. In other words, one film may be formed by performing the step of disposing the particles multiple times and the step of disposing the adhesive. In this modification, for example, the first thin film F1 is formed as follows.

[0132] Specifically, as shown in FIG. 14 , the step (S22) of arranging a plurality of first particles 1 shown in FIG. 6 and the step (S23) of arranging adhesive 20 shown in FIG. 7 are performed to form the state shown in FIG. 5 . Next, as shown in FIG. 15 , a plurality of seventh particles 7 are arranged on the plurality of first particles 1 (step S25). In this step (S25), similar to the step (S22) of arranging first particles 1, the seventh particles 7 are arranged side by side in the second direction. The seventh particles 7 have a magnetocaloric effect. The phase transition temperature of the seventh particles 7 may be different from that of the first particles 1, but is the same here. The maximum diameter of the seventh particles 7 is the same as that of the first particles 1, being 50 μm or more and 250 μm or less.

[0133] Next, similarly to the above embodiment, the adhesive 20 is hardened to a certain extent (step S24), thereby forming a first film.

[0134] 16, the first film is pressed to reduce its thickness (step S3). By performing step S3, the first thin film can be formed. The first thin film of this modification is formed by stacking the first particles 1 and the seventh particles 7, and therefore preferably has a thickness of more than 50 μm and not more than 500 μm.

[0135] As described above, the manufacturing method of the bed structure according to this modified example is the manufacturing method of the bed structure according to (4-7) above, and the step (S2) of forming the first film includes a step (S22) of arranging a plurality of first particles 1, a step (S23) of arranging adhesive 20 between the plurality of first particles 1, and a step (S25) of arranging a plurality of seventh particles 7 on the plurality of first particles 1 after the step (S23) of arranging adhesive 20. The plurality of seventh particles 7 have a magnetocaloric effect.

[0136] Here, the first film in which the seventh particles 7 are arranged is pressed onto the first particles 1 and adhesive 20, so that a thin film that maintains voids between the particles can be easily produced.

[0137] (5-3) Modification 3 In the above embodiment, the first thin film F1 is formed on the bottom surface 41 (step S2), but another thin film may be formed below the first thin film F1.

[0138] (5-4) Modification 4 In the above embodiment, a bed structure including a layer having particles with a first phase transition temperature and a layer having particles with a second phase transition temperature different from the first phase transition temperature has been described as an example, but the present invention is not limited to this.

[0139] The bed structure of this modification is the bed structure according to (4-1) above, in which the plurality of particles have the same phase transition temperature. As in the bed structure of this modification, the bed structure may include a plurality of particles having the same phase transition temperature.

[0140] (5-5) Modification 5 In the above embodiment, one layer contains particles with the same phase transition temperature, but this is not limiting. The bed structure of the present disclosure may contain particles with multiple phase transition temperatures in one layer. In this case, for example, in the bed structure, particles with multiple phase transition temperatures may be arranged so that the phase transition temperatures of the particles gradually increase from one end to the other end in the first direction.

[0141] The manufacturing method of the bed structure according to this modification is the manufacturing method of any one of the bed structures (4-7) to (4-9) above, in which the phase transition temperature of the first particles 1 is different from the phase transition temperature of the second particles 2.

[0142] In this way, bed structures with multiple particles having multiple phase transition temperatures may be produced.

[0143] (5-6) Modification 6 In the above embodiment, a bed structure including multiple layers L1 to L5 and a manufacturing method thereof have been described as an example, but the present disclosure may also be directed to a bed structure including a single layer and a manufacturing method thereof. Also, in the above embodiment, the thicknesses of the multiple layers L1 to L5 are the same, but they may be different.

[0144] In the above embodiment, the bed structure having a plurality of thin films F1 to F6 and the manufacturing method thereof are described as an example, but the present disclosure may also be directed to a bed structure having a single thin film and the manufacturing method thereof. Also, in the above embodiment, the thicknesses of the plurality of thin films F1 to F6 are the same, but they may be different.

[0145] (5-7) Modification 7 In the above embodiment, the bed structure 10 is manufactured using a container 40 having a bottom surface 41 and a side surface 42. However, the present invention is not limited to this. In this modification, the side surface 42 is omitted, and only the bottom surface 41 is used as the container.

[0146] (5-8) Modification 8 In the above embodiment, the bed structure 10 is described as not including the container 40. However, this modification is not limited to this. In this modification, one container 40 is provided to store the layers L1 to L5.

[0147] In the manufacturing method of the bed structure of this modification, the step of removing the container 40 (S15) is not performed, but a step of attaching the top surface opposite the bottom surface 41 to the side surface is performed. The top surface is a mesh filter having a plurality of pores smaller than the particles.

[0148] (5-9) Modification 9 In the above embodiment, the bed structure including crushed particles and the manufacturing method thereof have been described as an example, but the present invention is not limited to this. The shape of the particles may be spherical, pellet-shaped, or the like.

[0149] Although the embodiments and examples of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0150] 1: Particle (first particle in the claim) 2: Particle (second particle in the claim) 7: Particle (third particle in the claim) 10: Bed structure 20: Adhesive 30: Flow path 40: Container 100: Magnetic refrigeration system F11: Membrane (first membrane in the claim) F12: Membrane (second membrane in the claim)

[0151] Japanese Patent Application Laid-Open No. 2020-46085

Claims

1. A bed structure (10) for use in a magnetic refrigeration system (100) in which a fluid passes in a first direction, wherein a plurality of particles (1) having a magnetocaloric effect are arranged in the first direction and in a second direction intersecting the first direction, and the plurality of particles are bonded to each other with an adhesive (20) so as to form a flow path (30) through which the fluid passes between the plurality of particles, and the density of the particles in the first direction is greater than the density of the particles in the second direction.

2. The bed structure according to claim 1, wherein a plurality of said particles have the same phase transition temperature.

3. The bed structure according to claim 1, wherein the plurality of particles have a plurality of phase transition temperatures.

4. The bed structure according to claim 3, wherein the plurality of particles have a plurality of phase transition temperatures in the first direction and the same phase transition temperature in the second direction.

5. A bed structure according to any one of claims 1 to 4, wherein the maximum diameter of the plurality of particles is 50 μm or more and 250 μm or less.

6. A bed structure according to any one of claims 1 to 5, wherein the average porosity is 40% or more.

7. A method for manufacturing a bed structure (10) used in a magnetic refrigeration system (100), comprising: a step (S2) of forming a first film (F11) including a plurality of first particles (1) having a magnetocaloric effect and an adhesive (20); a step (S3) of pressing the first film to reduce the thickness of the first film; and a step (S4) of forming a second film (F12) including a plurality of second particles (2) having a magnetocaloric effect and an adhesive (20) on the reduced thickness of the first film.

8. A method for manufacturing a bed structure as described in claim 7, wherein the step of forming the first film includes the step (S22) of arranging a plurality of the first particles, and the step (S23) of arranging an adhesive between the plurality of first particles.

9. A method for manufacturing a bed structure as described in claim 7, wherein the step of forming the first film includes the steps of: arranging a plurality of the first particles (S22); arranging an adhesive between the plurality of the first particles (S23); and, after the step of arranging the adhesive, arranging a plurality of third particles (7) having a magnetocaloric effect on the plurality of the first particles (S25).

10. The method for manufacturing a bed structure according to claim 7 or 8, wherein the thickness of the thinned first film is not more than twice the maximum thickness of the first particles.

11. A method for manufacturing a bed structure according to any one of claims 7 to 10, wherein the maximum diameter of the first particles is 50 μm or more and 250 μm or less.

12. A method for manufacturing a bed structure according to any one of claims 7 to 11, wherein the phase transition temperature of the first particles is the same as the phase transition temperature of the second particles.

13. A method for manufacturing a bed structure according to any one of claims 7 to 11, wherein the phase transition temperature of the first particles is different from the phase transition temperature of the second particles.

14. A method for manufacturing a bed structure according to any one of claims 7 to 13, wherein in the step of forming the first film and the step of forming the second film, the first film and the second film are formed inside a container.

15. The method for manufacturing a bed structure according to claim 14, further comprising a step (S15) of removing the container.

16. A method for manufacturing a bed structure according to any one of claims 7 to 15, further comprising a step (S16) of confirming that a flow path through which a fluid passes has been formed.

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