JP5716629B2 - Manufacturing method of microchannel heat exchanger using magnetic refrigeration material and microchannel heat exchanger - Google Patents

Description

  The present invention relates to a method for manufacturing a microchannel heat exchanger using a magnetic refrigeration material, and a microchannel heat exchanger.

As an environmentally-friendly refrigeration technology, there are growing expectations for clean and energy-efficient magnetic refrigeration. It is known that a La (Fe, Si) ₁₃ -based material as a magnetic refrigeration material exhibits a high magnetocaloric effect, and a high magnetocaloric effect is exhibited at room temperature by containing hydrogen in this material (Patent Literature) 1). Alternatively, a method of operating at room temperature by containing Co instead of hydrogen has been proposed (Patent Document 2).

  Patent Document 2 describes that the shape of the magnetic refrigeration material is preferably a sphere or an ellipsoid, and the particle size is preferably 0.1 mm or more and 2 mm or less, and more preferably 0.4 mm or more and 1.5 mm or less. Has been. FIG. 12A shows a schematic cross-sectional view of a state in which a cylindrical tube is filled with a spherical magnetic refrigeration material. Reference numeral 100 denotes a spherical magnetic refrigeration material, and reference numeral 110 denotes a cylindrical tube.

  From the viewpoint of heat exchange between the refrigerant and the magnetic refrigeration material, a spherical shape having the largest specific surface area of the magnetic refrigeration material is preferable. However, when a spherical magnetic refrigeration material is used, pump power, that is, pressure loss becomes high. Furthermore, when the container is filled with a spherical magnetic refrigeration material, the individual magnetic refrigeration material particles are not completely fixed, and some particles are moved by the refrigerant, so that they are broken by collision with adjacent particles, resulting in fine powder. Will occur.

  Therefore, a microchannel structure has been proposed in which a through slit in contact with the surface of the magnetic refrigeration material is formed, and heat is exchanged between the magnetic refrigeration material and the refrigerant by flowing the refrigerant through the slit (Non-Patent Document 1). . FIG. 12B shows a schematic cross-sectional view of Non-Patent Document 1 and a perspective view of a microchannel. By adopting this structure, both low pressure loss and high heat exchange performance can be achieved.

  In order to obtain the desired heat exchange performance, both the slit width of the microchannel and the thickness of the magnetic refrigeration material must be about several mm or less (preferably about 1 mm or less). On the other hand, in Non-Patent Document 1, the slit width of the microchannel is about 0.15 mm, and the thickness of the magnetic refrigeration material (GaSiGe) is 5 mm. The Si substrate is etched to form a groove having a depth of 0.15 mm, and a microchannel is formed by bonding a plate of a magnetic refrigeration material having a thickness of 5 mm so as to face the surface on which the groove is formed.

JP 2003-96547 A JP 2008-150695 A

NASA Supported Hydrogen Research 2005 @University of Florida Lecture Chart, page 18, [online], [searched August 2, 2010], Internet <URL: http://www.mae.ufl.edu/NasaHydrogenResearch/ presentations / Review% 20Meeting% 20-% 20Other% 20Projects.pdf>

  However, in the structure of Non-Patent Document 1, a part of the microchannel structure is formed of Si that is not a magnetic refrigeration material, so that the magnetocaloric effect cannot be sufficiently obtained. Moreover, since the thermal expansion coefficient differs between Si and the magnetic refrigeration material, stress is generated at the interface due to temperature fluctuation, and in the worst case, there is a risk of peeling at the interface.

  In Non-Patent Document 1, the reason why the magnetic refrigeration material itself did not form the microchannel is that the magnetic refrigeration material is not a single crystal like the Si substrate, so that the etching process utilizing the crystal anisotropy cannot be performed, and the magnetic refrigeration material is magnetic. This is because the aforementioned microchannel structure cannot be formed by general deep groove machining such as electric discharge machining because the frozen material is mechanically brittle.

  On the other hand, in order to form a through slit having a width of about 0.5 mm or less, a height of about 5 mm, and a depth of about 20 mm in a massive magnetic refrigeration material, laser processing, electric discharge processing, or the like can be considered. However, the processing time is long, and deterioration of the surface roughness of the processed surface and occurrence of damage such as cracks and cracks are problems.

  An object of the present invention is to provide a manufacturing method for forming a microchannel heat exchanger with a magnetic refrigeration material.

The invention according to claim 1, which has been made in order to solve the above-described problem, is a method for manufacturing a microchannel heat exchanger using a magnetic refrigeration material in which the Curie temperature is changed by impregnation with hydrogen. In this manufacturing method, a substantially flat magnetic refrigeration material is impregnated with hydrogen, a magnetic refrigeration material impregnated with hydrogen in the impregnation step and a spacer are alternately stacked, and the spacer and the magnetic refrigeration material are joined. Thus, there is an assembling step of joining the magnetic refrigeration material via the spacer, and in the assembling step, a plurality of the spacers are arranged at intervals so as to form a flow path .

  If it is such a manufacturing method, a flow path (microchannel) can be formed without damages, such as a crack and a crack, by laminating | stacking and joining several substantially flat magnetic refrigeration materials. As will be described later, the microchannel can form a flow path by forming a groove on at least one surface of the magnetic refrigeration material or joining the magnetic refrigeration materials through a spacer. In order to form a groove on one surface of a flat magnetic refrigeration material, for example, it is possible to perform general lathe processing or wire cut processing. With such a method, the surface roughness of the processed surface deteriorates, cracks, The occurrence of damage such as cracking is suppressed.

  Further, in this manufacturing method, since the magnetic refrigeration material is impregnated with hydrogen before the magnetic refrigeration material is assembled, even if the magnetic refrigeration material expands by being impregnated with hydrogen, the magnetic refrigeration material is bonded to the magnetic refrigeration material bonded in advance. As in the case where the magnetic refrigeration material expands due to the impregnation of the magnetic refrigeration material, the stress is not concentrated at the joint portion of the magnetic refrigeration material.

  Therefore, it is possible to suppress the occurrence of cracks and cracks in the magnetic refrigeration material during production, and since the above-described stress is suppressed, cracks and cracks when subjected to magnetostriction due to an external magnetic field and stress due to refrigerant pressure Can also be suppressed.

As the magnetic refrigeration material, a LaFe _13- based material having a NaZn ₁₃ crystal structure as a main phase may be used as in claim 7 .
Various methods are conceivable as methods for joining the magnetic refrigeration materials. For example, there are a method of directly joining magnetic refrigeration materials at a high temperature, a method of forming a groove into a block-shaped material, and a method of forming a groove in advance when the material is sintered. Moreover, you may join as described in Claim 2.

  According to a second aspect of the present invention, in the manufacturing method of the microchannel heat exchanger according to the first aspect, in the assembling step, a joining member that joins at a temperature equal to or lower than a temperature at which hydrogen is desorbed from the magnetic refrigeration material is used. It is characterized by joining magnetic refrigeration materials.

In the microchannel heat exchanger manufactured by such a manufacturing method, it is possible to prevent the hydrogen impregnated in the impregnation step from desorbing.
The temperature at which hydrogen is desorbed is, for example, about 200 ° C. when the magnetic refrigeration material is a LaFe ₁₃ -based material having a NaZn ₁₃ crystal structure as a main phase. Therefore, it is conceivable to use a joining member that joins at a lower temperature.

As described above, the invention according to claim 1, set upright step, laminating the magnetic refrigeration materials and spacers alternately, by joining the spacer and the magnetic refrigeration materials, magnetic refrigeration materials via a spacer And a plurality of spacers are arranged at intervals so as to form a flow path.

  In the microchannel heat exchanger manufactured by such a manufacturing method, a region surrounded by the magnetic refrigeration material and the spacer serves as a flow path. Therefore, a flow path can be formed without forming a groove in the magnetic refrigeration material. Further, since the spacer can relieve the magnetic distortion caused by the external magnetic field and the stress applied to the magnetic refrigeration material by the pressure when the refrigerant passes through the flow path, the occurrence of cracks, cracks, etc. can be suppressed.

The Young's modulus of the spacer may be 1 to 0.01 GPa as in the method for manufacturing a microchannel heat exchanger according to claim 3 . By using such a Young's modulus spacer, the occurrence of cracks and cracks can be effectively suppressed.

Further, as the spacer, a rubber adhesive or a rubber sheet may be used as in the method of manufacturing a microchannel heat exchanger according to claim 4 . The rubber-based adhesive is an adhesive obtained by dissolving a synthetic resin or synthetic rubber in an organic solvent.

According to a fifth aspect of the present invention, in the method for manufacturing a microchannel heat exchanger according to the first or second aspect , the assembly step is a heat provided with a plurality of laminated bodies in which magnetic refrigeration materials and spacers are laminated. In the process of manufacturing the exchanger, at least a part of the spacer is arranged so that a plurality of stacked bodies are connected and stacked together.

With such a manufacturing method, a microchannel heat exchanger having a plurality of stacked bodies connected via spacers can be manufactured.
According to a sixth aspect of the present invention, in the method for manufacturing a microchannel heat exchanger according to the fifth aspect , the plurality of laminated bodies are arranged in a line, and the Curie temperature of each laminated body changes in the arrangement order. It is characterized by that.

  In the microchannel heat exchanger produced by such a manufacturing method, each laminate acts as a microchannel heat exchanger. Since the Curie temperature changes in the order of arrangement for each laminate, the operating temperature (the temperature that produces the magnetocaloric effect) can be changed for each laminate, which is effective for the fluid that passes through the laminate. Heat exchange can be performed.

Invention of Claim 8 is attached to a fixing member via the rubber-type adhesive agent or rubber sheet whose Young's modulus is 1-0.01GPa, or any one of Claims 1-4 . It is the microchannel heat exchanger manufactured with the manufacturing method of the microchannel heat exchanger.

  The fixing member is a portion to which a microchannel heat exchanger is attached in a heat exchange device such as a refrigerator. In the microchannel heat exchanger, since a rubber adhesive or a rubber sheet is disposed between the fixing member and the microchannel heat exchanger, a stress applied to the microchannel heat exchanger by the rubber adhesive or the rubber sheet. Can be mitigated and damage to the microchannel heat exchanger can be suppressed.

It is a perspective view of the magnetic refrigeration material which comprises the microchannel heat exchanger of Example 1, Comprising: (A) is before groove | channel formation, (B) is after groove | channel formation. It is a side view explaining the groove | channel formation process of Example 1. FIG. FIG. 6 is a perspective view illustrating an assembly process of Example 1. 2 is a perspective view showing a microchannel heat exchanger manufactured by the manufacturing method of Example 1. FIG. It is sectional drawing which shows the state which accommodated the microchannel heat exchanger of Example 1 in the case. It is side surface sectional drawing which shows the modification of the groove | channel formed in a magnetic refrigeration material. FIG. 10 is a perspective view illustrating an assembly process of Example 2. 6 is a front view showing a microchannel heat exchanger manufactured by the manufacturing method of Example 2. FIG. It is a front view which shows the state which fixed the microchannel heat exchanger manufactured with the manufacturing method of Example 2 to the refrigerator base. It is a figure which shows the microchannel heat exchanger manufactured with the manufacturing method of Example 3, Comprising: (A) is a top view, (B) is a side view, (C) is AA sectional drawing. It is. 6 is a perspective view showing a spacer of Example 3. FIG. (A) is heat exchanger sectional drawing which accommodated the small particle-shaped magnetic refrigeration material by a prior art, (B) is a schematic perspective view of the microchannel by a prior art.

  Embodiments of the present invention will be described below with reference to the drawings. It is needless to say that the present invention is not limited to the following examples and can take various forms as long as they belong to the technical scope of the present invention. In the drawings, there is a portion described in a ratio different from the actual for the purpose of facilitating understanding of the shape and the like.

[Example 1]
In this embodiment, a plate-like magnetic refrigeration material having grooves formed thereon is laminated, and a microchannel heat exchanger in which microchannels are formed by the grooves is manufactured.

(1.1) Groove Forming Step In this step, a groove is formed on one surface 11a of the rectangular flat magnetic refrigeration material 11 shown in FIG. 1A, and the groove 13 is formed as shown in FIG. The magnetic refrigeration material 21 in which is formed is prepared.

As the magnetic refrigeration material, a LaFe ₁₃ -based material having a NaZn ₁₃ crystal structure as a main phase is used. When this magnetic refrigeration material is impregnated with hydrogen, the Curie temperature changes, and the operating temperature of the magnetic refrigeration material (the temperature at which the magnetocaloric effect is developed) changes. The groove 13 of the magnetic refrigeration material 21 was formed by wire cutting. The grooves 13 may be formed by grinding or polishing other than wire cutting. This groove 13 forms a microchannel (flow path).

  A method for forming the groove 13 will be described more specifically. FIG. 2A is a side view of the magnetic refrigeration material 11 before performing the process of forming grooves. First, as shown in FIG. 2B, a groove 13a having a depth equal to or larger than the vertical width of the microchannel, that is, a depth equal to or larger than the groove 13, was formed on one surface 11a of the magnetic refrigeration material 11. Note that the vertical width and the horizontal width of the microchannel may be about several mm or less (preferably about 1 mm or less).

  Next, as shown in FIG. 2C, one surface 11a of the magnetic refrigeration material 11 was ground to be a flat surface. As a result, the depth of the groove 13a is reduced, and the groove 13 having a substantially micro-channel gap width is formed. This ground surface is referred to as a first surface 15.

  Next, as shown in FIG. 2D, in the magnetic refrigeration material 11, the surface 11b opposite to the surface 11a on which the groove 13a is formed (the surface opposite to the first surface 15, see FIG. 2A). Was ground to a flat surface. This ground surface is referred to as the second surface 17.

Thus, the flat magnetic refrigerating material 21 in which the groove 13 shown in FIG. 1B was formed was formed.
In the groove forming step, it is not always necessary to go through all the steps described above, and at least the step of forming the groove may be performed.

(1.2) Hydrogen impregnation step The magnetic refrigeration material 21 having the grooves 13 formed in the groove formation step is heat-treated in a hydrogen (H) atmosphere (about 200 ° C to 300 ° C, 1 atm) to impregnate the hydrogen. It was.

(1.3) Assembly process As shown in FIG. 3, the epoxy adhesive 19 (JEOL G20) is thinly applied to the first surface 15 located around the groove 13 in the magnetic refrigeration material 21 that has undergone the hydrogen impregnation process. It was spread and applied. This epoxy adhesive corresponds to the joining member of the present invention.

  It was laminated so that the second surface 17 (surface not shown in FIG. 3 which is located on the back side) of another magnetic refrigeration material 21 that had been subjected to the hydrogen impregnation step hit thereon. Similarly, a plurality of magnetic refrigeration materials 21 were laminated, and the magnetic refrigeration material 11 without grooves was laminated on the top. What laminated | stacked this magnetic refrigeration material respond | corresponds to the laminated body of this invention. And each magnetic refrigeration material was joined by the adhesive mentioned above. The bonding with the adhesive was performed at room temperature (15 ° C.).

  The microchannel heat exchanger 1 shown in FIG. 4 formed by joining the magnetic refrigeration materials 11 and 21 was manufactured by the above process. In the microchannel heat exchanger 1, a portion surrounded by the groove 13 of each magnetic refrigeration material 21 and the magnetic refrigeration material 21 or the magnetic refrigeration material 11 stacked above the one is one of the microchannel heat exchangers 1. The microchannel 23 communicates from the end surface (the front surface in FIG. 4) to the other end surface (the back surface in FIG. 4).

  5A and 5B are schematic cross-sectional views showing a state in which the microchannel heat exchanger 1 shown in FIG. 4 is housed in a case 3 for flowing a refrigerant. Heat exchange can be performed by filling the refrigerant from the ports provided at both ends of the case 3 and moving the refrigerant in synchronization with heat generation and heat absorption due to the magnetocaloric effect of the magnetic refrigeration material.

(1.4) Effect In the manufacturing method of the microchannel heat exchanger of the present embodiment, the assembly process is performed after the hydrogen impregnation process, and the magnetic refrigeration materials are joined and fixed. Therefore, compared with the case where hydrogen impregnation is performed after joining the magnetic refrigeration materials, it is possible to suppress the distortion of the microchannel heat exchanger 1 due to the expansion of the magnetic refrigeration material. As a result, it is possible to suppress the occurrence of cracks, cracks, and the like due to stress applied to the magnetic refrigeration material due to strain.

  In addition, the epoxy adhesive 19 that joins the magnetic refrigeration material can relieve magnetostriction due to an external magnetic field and stress due to the pressure when the refrigerant passes through the microchannel 23, thus causing cracks and cracks. Can be suppressed.

  Further, when the magnetic refrigeration materials are joined at a high temperature, the impregnated hydrogen is desorbed, but in this embodiment, such a problem is hardly caused because the joining can be performed at room temperature. In addition, when using the magnetic refrigeration material of a present Example, in order to suppress detachment | desorption of hydrogen, it is preferable to carry out at 200 degrees C or less. Examples of the adhesive satisfying such conditions include epoxy, rubber, and cyanoacrylate. As the epoxy system, a flexible one is desirable.

In the manufacturing method of this embodiment, since the first surface 15 and the second surface 17 ground or polished in the groove forming step are joined, a good joined state can be obtained.
Further, as the magnetic refrigeration materials, due to the use of LaFe _13-based material as a main phase an NaZn ₁₃ crystal structure, it can be expected high magnetocaloric effect or high heat exchange performance.

  In the present embodiment, the microchannel heat exchanger using the magnetic refrigeration material 21 in which the grooves 13 are linearly formed is illustrated, but the shape of the grooves is not limited to the above, and the magnetic refrigeration materials are stacked. Thus, various shapes can be formed such that the flow path is formed.

  For example, a plurality of grooves may be formed in one magnetic refrigeration material, and as shown in FIG. 6, the lower magnetic refrigeration is based on the joint surfaces of a plurality of magnetic refrigeration materials 25 stacked one above the other. A microchannel (in the figure) that communicates the ends of the microchannel heat exchanger by overlapping a groove 27 formed on the upper surface of the material 25 and a groove 29 formed on the lower surface of the upper magnetic refrigeration material 25. A configuration in which a flow path indicated by an arrow) may be formed.

[Example 2]
In this example, the magnetic refrigeration material of the same material as that of Example 1 is used, and the microchannel heat is formed by forming a microchannel with a spacer disposed between the magnetic refrigeration materials to be stacked without forming a groove in the magnetic refrigeration material. Manufacture exchangers.

(2.1) Hydrogen impregnation step The rectangular flat magnetic refrigeration material 31 shown in FIG. 7A is subjected to a heat treatment in a hydrogen (H) atmosphere (about 200 ° C. to 300 ° C., 1 atm), and hydrogen is Impregnated.

(2.2) Assembly Process In this embodiment, a rubber adhesive shown in FIG. The rubber adhesive is preferably a synthetic rubber, particularly a silicone. The Young's modulus at room temperature is 10 to 50 MPa. The spacer 33 is thick and long.

(2.2.1) Rubber Adhesive Lamination Process As shown in FIG. 7C, along two end portions located on opposite sides of one surface of the magnetic refrigeration material 31 that has undergone the hydrogen impregnation step. Thus, the two spacers 33 are arranged in parallel with a space therebetween. On top of that, another magnetic refrigeration material 31 that had undergone a hydrogen impregnation step was laminated. Then, as shown in FIG. 8, the spacer 33 was disposed on the laminated magnetic refrigeration material 31 as described above, and similarly, the spacer 33 and the magnetic refrigeration material 31 were alternately laminated in a plurality of stages. This state corresponds to the laminate of the present invention.

(2.2.2) Heat bonding process The plurality of magnetic refrigeration materials 31 and spacers 33 laminated by the lamination process are heated to 200 ° C., and then cooled at room temperature (15 ° C.) to form the surface of the spacer 33 and the magnetic refrigeration material. 31 was joined.

  Through the above steps, the microchannel heat exchanger 5 shown in FIG. 8 was manufactured. In the microchannel heat exchanger 5, a portion surrounded by each magnetic refrigeration material 31 and the spacer 33 becomes a microchannel 35. The thickness of the spacer 33 is the gap width of the microchannel 35.

(2.3) Effect Since the rubber adhesive (spacer 33) is joined to the magnetic refrigeration material 31 at a temperature at which the impregnated hydrogen does not desorb in the method of manufacturing the microchannel heat exchanger of the present embodiment, Hydrogen desorption can be suppressed.

  In the microchannel heat exchanger 5, a region surrounded by the magnetic refrigeration material 31 and the spacer 33 serves as a flow path. Therefore, the flow path can be formed without forming a groove in the magnetic refrigeration material 31.

  In addition, since the spacer 33 can relieve the magnetic distortion caused by the external magnetic field and the stress applied to the magnetic refrigeration material by the pressure when the refrigerant passes through the flow path, the occurrence of cracks and cracks can be suppressed.

  Note that the spacer of this example has a Young's modulus of 10 MPa. In order to relieve the stress described above and effectively suppress the generation of cracks and cracks, a material having a Young's modulus of 1 to 0.01 GPa may be used as the spacer. When the Young's modulus is 1 GPa or less, the stress can be sufficiently relaxed. When the Young's modulus is 0.01 GPa or more, the shape of the flow path can be maintained without deforming the spacer more than necessary even when a load is applied to the heat exchanger.

  In addition, although the structure which forms a flow path with two spacers was illustrated in the said Example, two or more several spacers may be arrange | positioned so that a flow path may be formed. For example, two flow paths can be formed by arranging three spacers 33 between two magnetic refrigeration materials 31.

  The rubber adhesive used for the spacer 33 can also be used when attaching the microchannel heat exchanger 5 to a refrigerator or the like. As shown in FIG. 9, a sheet 39 made of a rubber-based adhesive is disposed between the refrigerator base 37 and the microchannel heat exchanger 5, thereby joining the microchannel heat exchanger 5 to the refrigerator base. Can be considered.

  By joining the microchannel heat exchanger 5 in this way, the stress applied to the microchannel heat exchanger 5 and the load applied from the outside can be relaxed by the sheet 39 as well.

  A rubber sheet can be used instead of the rubber adhesive. In this case, a heat-weldable film can be disposed on the surface of the rubber sheet, or a heat-weldable rubber sheet itself can be used. As the rubber sheet, for example, a material such as silicone rubber can be used. As the heat-weldable film and rubber sheet, it is preferable to use a film that can be melted and welded at a temperature lower than the desorption temperature of hydrogen, or 200 ° C. or lower in the magnetic refrigeration material of this example. As the rubber sheet, a material having a Young's modulus (1 to 0.01 GPa) similar to that of the rubber adhesive may be used.

[Example 3]
In this example, the magnetic refrigeration material 31 having the same material and shape as in Example 2 was used, and a groove was not formed in the magnetic refrigeration material, but a microchannel was formed by a spacer disposed between the magnetic refrigeration materials to be stacked. Manufactures microchannel heat exchangers. In this embodiment, a fixed frame 43 formed in a frame shape is used as a spacer, and a plurality of microchannel units 41 are arranged in a line.

  10A to 10C show a microchannel heat exchanger 7 of this embodiment. 10A is a plan view of the microchannel heat exchanger 7, FIG. 10B is a side view, and FIG. 10C is a cross-sectional view taken along line AA in FIG. 10A. The microchannel heat exchanger 7 has a plurality of microchannel units 41.

  As shown in FIG. 11, the fixed frame 43 includes a pair of long support portions 45 and a connection portion 47 that connects both ends of the pair of support portions 45. The pair of support portions 45 are arranged in parallel with a space therebetween. A plurality of grooves 49 into which the magnetic refrigeration material is fitted are formed above and below the support portion 45. As shown in FIG. 10B, the upper and lower fixed frames 43 may have grooves 49 only on the inner side.

  The material of the fixed frame 43 is preferably a resin material that can maintain the shape and can relieve stress. As such a resin, for example, an epoxy resin, an ABS resin, polypropylene, polyethylene, or the like can be used.

The magnetic refrigeration material 31 has a rectangular flat plate shape as in the second embodiment, and fits in a gap formed by the two grooves 49 when the two fixed frames 43 are stacked.
Below, the manufacturing method of the microchannel heat exchanger 7 is demonstrated.

(3.1) Hydrogen impregnation step The magnetic refrigeration material 31 was heat-treated in a hydrogen (H) atmosphere (about 200 ° C. to 300 ° C., 1 atm) to impregnate hydrogen.

(3.2) Assembly process The magnetic refrigeration material 31 was fitted into the groove 49 of the fixed frame 43 and laminated as shown in FIG. At that time, the same adhesive as that used in Example 1 was thinly applied to the gap between the fixed frame 43 and the magnetic refrigeration material 31 and allowed to stand at room temperature (15 ° C.) for bonding.

  The microchannel heat exchanger 7 was manufactured by the above process. In the microchannel heat exchanger 7, a portion surrounded by each magnetic refrigeration material 31 and the fixed frame 43 becomes a microchannel 51. In this microchannel heat exchanger 7, a fixed frame 43 connects a plurality of microchannel units 41 and is laminated integrally.

(3.3) Effect In the manufacturing method of the microchannel heat exchanger of the present embodiment, a plurality of microchannel units 41 can be manufactured simultaneously.

  Moreover, in the manufacturing method of the microchannel heat exchanger of the present embodiment, since the fixed frame 43 is joined to the magnetic refrigeration material 31 at a temperature at which the impregnated hydrogen is not desorbed, desorption of hydrogen can be suppressed. .

  In the microchannel heat exchanger 7, a region surrounded by the magnetic refrigeration material 31 and the fixed frame 43 serves as a flow path. Therefore, the flow path can be formed without forming a groove in the magnetic refrigeration material 31. Moreover, since the microchannel unit 41 is connected via the fixed frame 43, a plurality of microchannel units 41 can be easily handled.

  In addition, in the said Example, although the structure which joins the fixed frame 43 and the magnetic refrigeration material 31 with the adhesive agent was illustrated, you may join a magnetic refrigeration material by the method of other than that. For example, the magnetic refrigeration material 31 can be joined via the fixed frame 43 by fixing the fixed frames 43 with bolts or the like. In this case, since the fixed frame 43 does not necessarily relieve stress, a rigid material such as metal may be used as the material of the fixed frame 43.

  The plurality of microchannel units 41 may be formed of magnetic refrigeration materials having different Curie temperatures. Specifically, in FIG. 10A, the operation temperature (the temperature at which the magnetocaloric effect is developed) decreases stepwise from left to right (in the direction of arrow B) in the order of arrangement. May be. That is, the leftmost microchannel unit 41 is composed of a magnetic refrigeration material having the highest operating temperature, and the microchannel unit is composed of a magnetic refrigeration material having a lower operating temperature toward the right side.

With this configuration, a microchannel heat exchanger having a large operating temperature range as a whole can be obtained, and heat can be effectively exchanged with the fluid passing through the flow path.
Moreover, in the said Example, although the structure which uses the frame type fixed frame 43 as a spacer was illustrated, the spacer of other shapes may be sufficient. For example, a configuration using a spacer including only the support portion 45 without the connecting portion 47 may be used, or only a part of the spacers may be a long spacer such as the support portion 45 and a plurality of microchannels. A structure in which a plurality of microchannel units 41 are connected and laminated together by using a spacer having the same length as the magnetic refrigeration material in the same manner as the spacer 33 in FIG. 7C. It may be.

DESCRIPTION OF SYMBOLS 1 ... Microchannel heat exchanger, 3 ... Case, 5 ... Microchannel heat exchanger, 7 ... Microchannel heat exchanger, 11 ... Magnetic refrigeration material, 13 ... Groove, 15 ... 1st surface, 17 ... 2nd surface, DESCRIPTION OF SYMBOLS 19 ... Epoxy adhesive, 21 ... Magnetic refrigeration material, 23 ... Micro channel, 25 ... Magnetic refrigeration material, 27 ... Groove, 29 ... Groove, 31 ... Magnetic refrigeration material, 33 ... Spacer, 35 ... Micro channel, 37 ... Refrigeration Machine base, 39 ... sheet, 41 ... microchannel unit, 43 ... fixed frame, 45 ... support part, 47 ... connecting part, 49 ... groove, 51 ... microchannel

Claims (8)

A method of manufacturing a microchannel heat exchanger using a magnetic refrigeration material whose Curie temperature changes by impregnation with hydrogen,
An impregnation step of impregnating hydrogen into a substantially flat magnetic refrigeration material;
An assembly step of joining the magnetic refrigeration material via the spacer by alternately laminating the magnetic refrigeration material impregnated with hydrogen and the spacer in the impregnation step , and joining the spacer and the magnetic refrigeration material; Have
In the assembling step, a plurality of the spacers are arranged at intervals so as to form a flow path . 2. The microchannel heat exchanger according to claim 1, wherein in the assembly step, the magnetic refrigeration material is joined through a joining member that joins at a temperature equal to or lower than a temperature at which hydrogen is desorbed from the magnetic refrigeration material. Manufacturing method. The method of manufacturing a microchannel heat exchanger according to claim 1 or 2 , wherein the spacer has a Young's modulus of 1 to 0.01 GPa. The method for manufacturing a microchannel heat exchanger according to any one of claims 1 to 3, wherein the spacer is a rubber adhesive or a rubber sheet. The assembly step is a step of manufacturing a heat exchanger including a plurality of laminated bodies in which the magnetic refrigeration material and the spacer are laminated,
3. The method of manufacturing a microchannel heat exchanger according to claim 1 , wherein at least a part of the spacer is arranged so as to connect and stack together a plurality of the stacked bodies. . The method of manufacturing a microchannel heat exchanger according to claim 5 , wherein the plurality of laminated bodies are arranged in a line, and the Curie temperature of each of the laminated bodies changes in the arrangement order. Examples magnetic refrigeration materials, NaZn ₁₃ manufacturing method of microchannel heat exchanger as claimed in any one of claims 6, wherein the use of LaFe _13-based material as a main phase crystal structure. The manufacture of the microchannel heat exchanger according to any one of claims 1 to 4 , wherein the microchannel heat exchanger is attached to the fixing member via a rubber adhesive or a rubber sheet having a Young's modulus of 1 to 0.01 GPa. A microchannel heat exchanger manufactured by the method.