Heat exchanger and manufacturing method thereof

Abstract

To provide a heat exchanger capable of improving heat exchange efficiency of a partition wall, and a method for manufacturing the same.SOLUTION: A heat exchanger 1 comprises a partition wall 3 that partitions two fluids having different temperatures. A plurality of grooves 4 having a depth of 100 μm to 400 μm is formed in a thickness direction of the partition wall 3 on an outer surface 3A of the partition wall 3, which is a surface in contact with the fluid with a lower heat transfer rate of the two fluids.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger having a partition wall that separates two fluids at different temperatures, and a method for manufacturing the same. [Background technology]

[0002] Conventionally, heat exchangers using various heat transfer methods have been widely used as devices for transferring heat between two fluids of different temperatures. In surface-type (partition-wall) heat exchangers, the two fluids flow through two spaces separated by a partition, and heat exchange between the two fluids is achieved by heat transfer through the partition.

[0003] In recent years, research and development into energy efficiency has been actively conducted to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. To contribute to energy efficiency, heat exchangers are required to improve their heat exchange efficiency. To improve heat exchange efficiency, structures such as those with fins on the partition walls or those with pores on the heat transfer surface of the partition walls are adopted to increase the heat transfer area.

[0004] For example, a heat exchanger is known that includes heat transfer tubes through which a refrigerant circulates and fins that come into contact with the heat transfer tubes, the fins having fin bodies with fine grooves on the surfaces thereof (see Patent Document 1).

[0005] Further, for example, a heat exchanger made of aluminum or an aluminum alloy and having metal fins with an aluminum anodized film formed on the surface thereof is known (see Patent Document 2). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2017-150756 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-252192 Summary of the Invention [Problem to be solved by the invention]

[0007] Due to the need for manufacturing costs and space, partition-type heat exchangers often do not include heat transfer fins, and in such cases, heat is exchanged directly through the metal partitions. Even in such heat exchangers, improving the heat exchange efficiency of the partitions remains an issue. Even in heat exchangers with heat transfer fins, further improvements in the heat exchange efficiency of the entire heat exchanger are required.

[0008] A major factor that determines the performance of a heat exchanger is the heat transfer coefficient (its inverse is thermal resistance) between the fluid and the partition wall surface that exchanges heat. When the fluid is a gas, the heat transfer coefficient is orders of magnitude smaller than when the fluid is a liquid, limiting the overall performance of the heat exchanger. The heat transfer coefficient is determined by the Reynolds number (flow velocity, kinematic viscosity, and characteristic dimensions) and the fluid-specific Prandtl number and Nusselt number, but in the case of forced convection, the partition wall surface roughness also has an effect. Generally, the greater the surface roughness, the greater the actual surface area in contact with the fluid, which tends to increase the heat transfer coefficient due to factors such as the destruction of the boundary layer. However, there is a complex relationship that includes pressure loss, and so in the past, this was left to the surface roughness determined by manufacturing methods such as machining and casting.

[0009] The present invention provides a heat exchanger that improves the heat exchange efficiency of a partition wall and a method for manufacturing the same. [Means for solving the problem]

[0010] The present invention provides A heat exchanger having a partition wall that separates two fluids of different temperatures, A first wall surface of the partition wall, which is the surface that comes into contact with the fluid having a lower heat transfer coefficient out of the two fluids, has a plurality of grooves having a depth of 100 μm to 400 μm in the thickness direction of the partition wall. a plurality of plate-shaped fins each having a pair of heat transfer surfaces; is formed 、 the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, A plurality of grooves having a depth of 100 μm to 400 μm are formed in the pair of heat transfer surfaces in the thickness direction of each of the fins. .

[0011] The present invention also provides A heat exchanger that has a partition wall that separates a gas from a liquid and performs heat exchange between the gas and the liquid, A first wall surface of the partition wall, which is the surface that comes into contact with the gas, has a plurality of grooves with a depth of 100 μm to 400 μm in the thickness direction of the partition wall. a plurality of plate-shaped fins each having a pair of heat transfer surfaces; is formed 、 the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, A plurality of grooves having a depth of 100 μm to 400 μm are formed in the pair of heat transfer surfaces in the thickness direction of each of the fins. .

[0012] The present invention also provides A method for manufacturing a heat exchanger, comprising: The partition wall that separates two fluids at different temperatures is formed using additive manufacturing. When forming the partition wall based on the additive manufacturing, a first wall surface of the partition wall, which is a surface that comes into contact with the fluid with a lower heat transfer coefficient of the two fluids, is provided with a plurality of grooves having a depth of 100 μm to 400 μm in a thickness direction of the partition wall. a plurality of plate-shaped fins each having a pair of heat transfer surfaces; Form death, the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, A plurality of grooves having a depth of 100 μm to 400 μm are formed in the thickness direction of each of the fins on the pair of heat transfer surfaces. . [Effects of the Invention]

[0013] According to the present invention, the heat exchange efficiency can be improved by intentionally designing the surface of the partition wall. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view showing a schematic configuration of a heat exchanger 1 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing one fin formed on the partition wall 3. [Figure 3] 2 is an enlarged perspective view showing a plurality of grooves 4 formed on an outer surface 3A of a partition wall 3. FIG. [Figure 4] 4 is a cross-sectional view of the outer surface 3A of the partition wall 3 taken along the line IV-IV in FIG. [Figure 5]3 is a cross-sectional view of the fin 5 taken along the line VV in FIG. 2. FIG. [Figure 6] 3 is an explanatory diagram showing the detailed structure of a heat transfer surface 21 of a fin 5. FIG. [Figure 7] FIG. 2 is a perspective view of a pin-shaped fin 7. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, a heat exchanger according to one embodiment of the present invention and a method for manufacturing the same will be described with reference to the drawings.

[0016] 1 and 2, the heat exchanger 1 mainly comprises a partition wall 3, a plurality of plate-like fins 5, a plurality of pin-like fins 7 (hereinafter referred to as pin-like fins 7), and a shell 9. The heat exchanger 1 performs heat exchange between two fluids (first fluid, second fluid) of different temperatures separated by the partition wall 3 through indirect contact between the two fluids.

[0017] The partition wall 3 is a cylindrical body with a bottom and constitutes the body of the heat exchanger 1. The partition wall 3 has a substantially cylindrical side periphery 11 and a bottom 13 provided to close one opening (here, the lower side) of the side periphery 11. A first fluid 14 (e.g., water at room temperature) containing a relatively low-temperature liquid to be heated is injected inside the partition wall 3. Furthermore, a second fluid 15 (here, high-temperature combustion gas from a combustor, not shown) containing gas at a higher temperature than the first fluid flows outside the partition wall 3.

[0018] As shown in FIGS. 3 and 4 , a plurality of grooves 4 are formed on the outer surface 3A (first wall surface) of the partition wall 3 and are arranged at a predetermined interval L1. The plurality of grooves 4 extend obliquely upward (here, in a direction tilting upward to the right) on the outer surface 3A of the side peripheral portion 11. Because the plurality of grooves 4 extend obliquely upward, the second fluid 15 can easily flow along the axial and circumferential directions of the side peripheral portion 11. Although not shown, the plurality of grooves 4 are also formed on the outer surface 3A of the bottom portion 13. Note that the plurality of grooves 4 are not formed as a surface roughness during the manufacturing of the partition wall 3 but are formed by design.

[0019] The depth D1 of the plurality of grooves 4 (depth in the thickness direction of the partition wall 3) is preferably set to 100 μm to 400 μm. Similarly, the width W1 of the plurality of grooves 4 is preferably set to about twice the depth D1 (200 μm to 800 μm). Similarly, the interval L1 between adjacent grooves 4 is preferably set to 100 μm to 300 μm.

[0020] By providing such a plurality of grooves 4 on the outer surface 3A of the partition wall 3 through which the second fluid 15 flows, the heat exchange efficiency of the partition wall 3 can be improved. In particular, when the second fluid 15 is a gas, the heat transfer coefficient is significantly smaller than that of a liquid. However, by providing fine irregularities of 100 μm to 400 μm on the outer surface 3A of the partition wall 3, the surface area is increased, the boundary layer flow can be controlled, and the heat exchange efficiency can be improved while maintaining the overall size. Furthermore, since there is no need to attach a member to the heat exchanger 1 to promote thermal efficiency in order to improve the heat exchange efficiency, the heat exchanger 1 does not become larger. Furthermore, because the depth D1 of the grooves 4 is fine, the appearance of the partition wall 3 is not affected.

[0021] The amount of heat transfer between two fluids separated by a partition wall 3 can also be thought of as thermal resistance. Thermal resistance is the reciprocal of the heat transfer coefficient (thermal conductivity). If the thermal resistance due to heat transfer between the first fluid 14 and partition wall 3 is R1, the thermal resistance due to heat conduction within partition wall 3 is R2, and the thermal resistance due to heat transfer between the second fluid 15 and partition wall 3 is R3, then the composite thermal resistance is the sum of the three thermal resistances: R1 + R2 + R3, just like the electrical resistance in an electrical circuit. This is called the law of similarity between heat and electricity. Because we want to exchange a large amount of thermal energy between the first fluid 14 and the second fluid 15, reducing the largest thermal resistance is effective in reducing the composite thermal resistance. In other words, increasing the heat transfer coefficient on the surface in contact with the fluid with low thermal conductivity is effective. Conversely, changing the heat transfer coefficient or thickness of partition wall 3, which has low thermal resistance to begin with, has almost no effect on the overall composite thermal resistance.

[0022] The partition walls 3 are integrally molded parts that are integral with the fins 5 and the pin-shaped fins 7. The partition walls 3, the fins 5, and the pin-shaped fins 7 are made of the same metal material (aluminum in this example).

[0023] A plurality of fins 5 are formed on the outer surface 3A of the partition wall 3. As also shown in Figure 2, each fin 5 extends in its longitudinal direction from the side periphery 11 to the bottom 13 of the partition wall 3. Each fin 5 includes a side portion (first portion) 17 having an inner edge connected to the outer surface of the side periphery 11, and a base portion (second portion) 19 having an inner edge connected to the outer surface of the bottom 13.

[0024] Each fin 5 has a pair of heat transfer surfaces 21, 21 (main heat transfer surfaces) that are arranged so as to intersect or substantially perpendicularly to the circumferential direction of the side periphery 11.

[0025] 2, the side portion 17 of each fin 5 forms a portion that is spirally curved obliquely upward (i.e., in the longitudinal direction) from the upper edge of the base portion 19 so as to follow the side peripheral portion 11 of the partition wall 3. By curving at least a portion of each fin 5 in this manner, the flow of fluid near the surfaces of the multiple fins 5 can be made smoother (the flow velocity of the fluid can be increased).

[0026] The width of the side portion 17 of each fin 5 (the distance between the outer edge 17A and the inner edge 17B) is substantially uniform over substantially the entire length (see FIG. 1). However, the upper edge 17C of the side portion 17 is formed so as to form an acute angle with the outer surface 3A of the partition wall 3 in a side view. Note that the side portion 17 may have at least a partially curved portion (i.e., a portion having a curved surface as a heat transfer surface). The curved portion is not limited to a spiral shape, and may have at least a curved surface.

[0027] 5, the side portion 17 of each fin 5 is configured to taper from its inner edge 17B to its outer edge 17A in a cross section perpendicular to the longitudinal direction (cross section taken along line VV in FIG. 2). The space between adjacent fins 5 (i.e., the space between adjacent heat transfer surfaces 21) gradually expands from the inside (the partition wall 3 side) to the outside. This makes it possible to prevent fluid from stagnating between adjacent fins 5.

[0028] A plurality of grooves 25 are formed in the pair of heat transfer surfaces 21, 21 of the side portion 17, and are arranged at predetermined intervals from the inner edge 17B to the outer edge 17A. From the viewpoint of improving heat exchange efficiency, the depth D2 of the plurality of grooves 25 (the depth in the thickness direction of each fin 5, which is approximately perpendicular to the heat transfer surfaces 21, 21) is preferably set to 100 μm to 400 μm. Similarly, the width W2 of the plurality of grooves 25 is preferably set to about twice the depth D2 (200 μm to 800 μm). Similarly, the interval L2 between adjacent grooves 25 is preferably set to 100 μm to 300 μm. Note that the grooves 25 may be formed on at least one of the heat transfer surfaces 21.

[0029] The base 19 of each fin 5 is substantially linear in the longitudinal direction (as viewed from the bottom). The base 19 extends from the lower edge 17D of the side portion 17 (see FIG. 6) along the bottom 13 of the partition wall 3. In a side view, the base portion 19 has a protrusion 31 that protrudes downward and has a substantially right-angled apex. Although not shown, the base portion 19 is configured to taper from its inner edge toward its outer edge, similar to the side portion 17.

[0030] Similar to the side portion 17, a plurality of grooves 125 are formed on the pair of heat transfer surfaces 21, 21 of the base portion 19, but the extending direction of these grooves 125 differs from that of the grooves 25 of the side portion 17. More specifically, as shown in FIG. 6 , the grooves 25 of the side portion 17 each extend in the longitudinal direction (here, approximately the vertical direction) along the outer surface 3A (side peripheral surface) of the side peripheral portion 11 of the partition wall 3. On the other hand, the grooves 125 of the base portion 19 each extend toward the outer surface 3A (bottom surface) of the bottom portion 13 of the partition wall 3 (here, in a direction tilting upward and to the left). The depth, width, and spacing of each groove 125 can be set similarly to those of the grooves 25 of the side portion 17.

[0031] In this way, by guiding the second fluid near the bottom surface of the bottomed cylinder to flow toward the bottom surface using multiple grooves 125, heat transfer at the bottom 13 of the bottomed cylinder can be promoted, and by guiding the second fluid near the side surface of the bottomed cylinder to flow along the side surface using multiple grooves 25, heat transfer at the side surface 11 of the bottomed cylinder can be promoted.

[0032] In this embodiment, the partition 3 forms a cylindrical body with a bottom, so an example is shown in which each fin 5 has a base 19, but if the partition 3 forms another structure (for example, a tubular body), the base 19 can be omitted.

[0033] At the bottom 13 of the partition wall 3, the inner edges of the bases 19 of the multiple fins 5 define a substantially circular area in which the multiple pin-shaped fins 7 are arranged. As shown in FIG. 7, each pin-shaped fin 7 has a tapered cylindrical (or conical) shape. A multiple number of ridges 41 extending in the longitudinal direction (projecting direction) are formed on the circumferential surface of each pin-shaped fin 7. The multiple ridges 41 are arranged at predetermined intervals in the circumferential direction.

[0034] The plurality of protrusions 41 increases the surface area of ​​each pin-shaped fin 7. Furthermore, forming the plurality of protrusions 41 on the tapered pin-shaped fins 7 also has the effect of reducing the thickness of the thermal boundary layer formed near the surface of the pin-shaped fin 7. As a result, the thermal resistance to the first fluid 14 inside the partition wall 3 decreases, and convective heat transfer of the first fluid is promoted.

[0035] An unsealed anodized aluminum coating is formed on the inner surface 3B (second wall surface) of the partition wall 3. The anodized aluminum coating has a plurality of pores, each with a pore diameter of 10 nm to 30 nm. The inner surface 3B of the partition wall 3 may also have fine irregularities of 100 μm to 400 μm, similar to the outer surface 3A of the partition wall 3. However, if the first fluid is a liquid, the effect on the heat transfer rate is small. If the first fluid is a liquid, foreign matter contained in the liquid may become trapped in the fine irregularities, which may actually be unhygienic. Therefore, the inner surface 3B (second wall surface) of the partition wall 3 has an anodized aluminum coating in which a plurality of pores, each with a pore diameter of 10 nm to 30 nm, are formed. In this way, in the heat exchanger 1, the fins 5 formed on the outer surface 3A of the partition wall 3 can promote heat transfer between the second fluid and the partition wall 3, while the pores formed on the inner surface 3B of the partition wall 3 can promote heat transfer between the first fluid and the partition wall 3. However, such an alumite coating may be omitted. Also, the alumite coating may be formed only on a part of the inner surface 3B of the partition wall 3.

[0036] 1, the shell 9 is generally cylindrical and is provided so as to cover the outside of the plurality of fins 5. As a result, a flow path for the second fluid 15 is defined by the inner surface 9A of the shell 9 and the outer surface 3A of the partition wall 3, and the plurality of fins 5 are located within this flow path.

[0037] The shell 9 has an upper portion 51 connected to the outer edges of the multiple fins 5 located on the opposite side from the partition wall 3, and a lower portion 53 connected to the lower edge of the upper portion 51 and extending downward. The lower edge 51A of the upper portion 51 is connected to the corner of the protrusion 31 at the base 19 of each fin 5. The lower portion 53 is located further outward (here, below) the pin-shaped fins 7 and has a substantially circular opening 55. The opening 55 forms an inlet for the second fluid 15. Such a shell 9 makes it possible to efficiently guide the second fluid to the fins 5 provided on the bottomed cylinder.

[0038] In manufacturing the heat exchanger 1 having the above-described configuration, the partition wall 3, the multiple fins 5, and the multiple pin-shaped fins 7 are integrally molded based on additive manufacturing using a known 3D printing technology. The processing method used for additive manufacturing is not particularly limited as long as it can realize the above-described structure. For example, the heat exchanger 1 is molded by simultaneously irradiating the area to be molded with metal powder and a laser (or electron beam) and stacking the molten metal powder into the above-described shape.

[0039] The shell 9 may be integrally molded together with the partition wall 3 or the like. Alternatively, the shell 9 may be formed from a metal material different from the metal material constituting the partition wall 3, and then attached by welding or the like so as to cover the outside of the plurality of fins 5.

[0040] The unsealed anodized aluminum coating on the inner surface 3B of the partition wall 3 is formed by a known anodizing process (anodic oxidation treatment of aluminum). The structure (pore diameter, etc.) of the multiple pores in the anodized aluminum coating can be confirmed using, for example, a field emission scanning electron microscope (FE-SEM).

[0041] When using the heat exchanger 1, for example, a user injects water as a first fluid inside the partition wall 3, and then operates a combustor (e.g., a gas burner) disposed below the heat exchanger 1. This causes combustion gas from the combustor, as a second fluid, to be introduced through the opening 55 in the shell 9. The combustion gas flows between the multiple fins 5 located between the partition wall 3 and the shell 9 and is discharged from the open top of the shell 9. At this time, the heat of the combustion gas is transferred to the partition wall 3, the fins 5, and the pin-shaped fins 7, and then to the first fluid via the inner surface 3B of the partition wall 3. This heat exchange between the combustion gas and water can increase the temperature of the water inside the partition wall 3 (ultimately boiling it).

[0042] In this way, in the heat exchanger 1, by integrally molding the partition walls 3 and the multiple fins 5, the thermal resistance at the interfaces between the partition walls 3 and the fins 5 is reduced, and by forming grooves of an appropriate depth in the multiple fins 5 having curved portions (here, side portions 17), the heat transfer area of ​​the fins 5 can be increased and the flow of the second fluid near the surfaces of the fins 5 can be made smoother. As a result, the heat exchange efficiency of the heat exchanger 1 can be improved.

[0043] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiment may be combined in any manner without departing from the spirit of the invention.

[0044] The heat exchanger 1 may include the partition walls 3 having a plurality of grooves 4 formed therein, and may not include the fins 5 or the shell 9. In addition, when the heat exchanger 1 includes the fins 5 and the shell 9, it is sufficient that the number of fins 5 provided is sufficient to support the shell 9 (for example, three).

[0045] The plurality of grooves 4 of the partition wall 3 do not have to be formed over the entire outer surface 3A. For example, they may be formed only on the outer surface 3A of the side periphery 11, or only on the outer surface 3A of the bottom 13. Furthermore, the plurality of grooves 4 may be formed only partially on the outer surface 3A of the side periphery 11, or only partially on the outer surface 3A of the bottom 13.

[0046] The partition wall 3 of the heat exchanger 1 is not limited to a bottomed cylindrical body, and various shapes used in known heat exchangers can be adopted. For example, the partition wall 3 may be a tubular body that separates the first fluid and the second fluid. In this case, the first fluid flows inside the partition wall 3 in a predetermined direction.

[0047] The first and second fluids do not have to be a combination of liquid and gas, and any combination of fluids (for example, a combination of liquids or gases) can be used. The heat exchanger 1 only needs to use at least two fluids, and may perform heat exchange using three or more fluids.

[0048] Examples of applications of the heat exchanger 1 include refrigerators, industrial heat exchangers, plate heat exchangers, and pipe-like passage heat exchangers. The heat exchanger 1 can also be used as part of a device or machine that functions as a heat exchanger by having a partition wall. Examples of applications of such heat exchanger 1 include fluid passage structures such as air-cooled engine heads, radiators, oil coolers, water heaters, air conditioners, EGR coolers, and Stirling engines.

[0049] This specification describes at least the following: In parentheses, components corresponding to those in the above-described embodiments are shown as examples, but the present invention is not limited to these.

[0050] (1) A heat exchanger (heat exchanger 1) having a partition (partition 3) that separates two fluids of different temperatures, A heat exchanger, wherein a first wall surface (outer surface 3A) of the partition wall, which is the surface that comes into contact with the fluid having the lower heat transfer coefficient out of the two fluids, has a plurality of grooves (grooves 4) formed thereon in a thickness direction of the partition wall and having a depth of 100 μm to 400 μm.

[0051] According to (1), among the wall surfaces of the partition wall separating two fluids, a first wall surface of the partition wall, which is the surface that comes into contact with the fluid with a low heat transfer coefficient, has a plurality of grooves with a depth of 100 μm to 400 μm formed in the thickness direction of the partition wall. This increases the surface area of ​​the partition wall. As a result, it becomes possible to improve the heat exchange efficiency of the heat exchanger.

[0052] (2) The heat exchanger according to (1), wherein a plurality of pores each having a pore diameter of 10 nm to 30 nm are formed on a second wall surface (inner surface 3B) of the partition wall, which is the surface that comes into contact with the fluid having the higher heat transfer coefficient out of the two fluids.

[0053] According to (2), the plurality of grooves formed on the first wall surface of the partition wall can promote heat transfer between one of the two fluids (e.g., gas) and the partition wall, while the pores formed on the second wall surface of the partition wall can promote heat transfer between the other of the two fluids (e.g., liquid) and the partition wall.

[0054] (3) A plurality of plate-shaped fins (fins 5) are formed on the first wall surface of the partition wall and have pairs of heat transfer surfaces (heat transfer surfaces 21), the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, The heat exchanger according to (1) or (2), wherein a plurality of grooves (grooves 25) having a depth of 100 μm to 400 μm are formed in the pair of heat transfer surfaces in the thickness direction of each of the fins.

[0055] According to (3), by integrally molding the partition walls and the fins, it is possible to reduce the thermal resistance at the interface between the partition walls and the fins. Also, by forming grooves with a depth of 100 μm to 400 μm on the fins with curved portions, it is possible to increase the heat transfer area of ​​the fins and smooth the flow of fluid near the fin surfaces. As a result, it is possible to improve the heat exchange efficiency of the heat exchanger.

[0056] (4) The partition wall constitutes a bottomed cylindrical body, The plurality of fins are connected to a bottom surface (bottom portion 13) and a side peripheral surface (side peripheral portion 11) that constitute the outer surface of the bottomed cylinder, In the first portion (side portion 17) of each of the fins connected to the bottom surface of the bottomed cylinder, the plurality of grooves each extend toward the bottom surface, A heat exchanger as described in (3), wherein in the second portion (base 19) of each fin connected to the side peripheral surface of the bottomed cylinder, the plurality of grooves each extend along the side peripheral surface.

[0057] According to (4), by using the grooves to guide the fluid near the bottom surface of the cylinder toward the bottom, heat transfer at the bottom of the cylinder can be promoted. Also, by using the grooves to guide the fluid near the side peripheral surface of the cylinder along the side peripheral surface, heat transfer at the side peripheral portion of the cylinder can be promoted.

[0058] (5) A heat exchanger as described in (4), further comprising a shell (shell 9) provided to cover the outside of the plurality of fins and to which the outer edge portions (outer edge 17A) of the plurality of fins opposite the partition wall are connected.

[0059] According to (5), the shell that covers the outside of the multiple fins makes it possible to efficiently guide the fluid to the fins provided on the bottomed cylinder.

[0060] (6) A heat exchanger as described in (4) or (5), further comprising a plurality of pin-shaped fins (pin-shaped fins 7) each protruding outward in an area on the bottom surface of the bottomed cylinder where the plurality of fins are not formed.

[0061] According to (6), the pin-shaped fins can effectively promote heat transfer at the bottom of the bottomed cylinder.

[0062] (7) The heat exchanger according to any one of (4) to (6), wherein the curved portions of the plurality of fins are formed in a spiral shape.

[0063] According to (7), the flow of the fluid near the surfaces of the multiple fins can be made smoother (the flow velocity of the fluid can be increased).

[0064] (8) The heat exchanger according to any one of (3) to (7), wherein each of the fins has a cross section that tapers in a direction away from the partition wall.

[0065] According to (8), stagnation of fluid between adjacent fins can be suppressed.

[0066] (9) A heat exchanger that has a partition wall that separates gas and liquid and performs heat exchange between the gas and liquid, A heat exchanger, wherein a plurality of grooves having a depth of 100 μm to 400 μm are formed in a first wall surface of the partition wall, which is the surface that comes into contact with gas, in a thickness direction of the partition wall.

[0067] According to (9), a plurality of grooves having a depth of 100 μm to 400 μm are formed in the first wall surface of the partition wall in the thickness direction of the partition wall. This increases the surface area of ​​the partition wall. As a result, it is possible to improve the heat exchange efficiency of the heat exchanger.

[0068] (10) The heat exchanger according to (9), wherein a plurality of pores each having a pore diameter of 10 nm to 30 nm are formed in a second wall surface of the partition wall, which is the surface that comes into contact with the liquid.

[0069] According to (10), the plurality of grooves formed in the first wall surface of the partition wall can promote heat transfer between the gas and the partition wall, while the pores formed in the second wall surface of the partition wall can promote heat transfer between the liquid and the partition wall.

[0070] (11) A method for manufacturing a heat exchanger (heat exchanger 1), The partition (partition 3) that separates the two fluids at different temperatures is formed using additive manufacturing. A method for manufacturing a heat exchanger, wherein when the partition wall is molded based on the additive manufacturing, a plurality of grooves (grooves 4) having a depth of 100 μm to 400 μm in the thickness direction of the partition wall are formed on a first wall surface (outer surface 3A) of the partition wall that is provided on the high-temperature fluid side of the two fluids.

[0071] According to (11), when the partition walls of a heat exchanger are formed by additive manufacturing, a plurality of grooves having a depth of 100 μm to 400 μm in the thickness direction of the partition wall are formed on the first wall surface of the partition wall provided on the high-temperature fluid side. This increases the surface area of ​​the partition wall. As a result, it becomes possible to improve the heat exchange efficiency of the heat exchanger. [Explanation of symbols]

[0072] 1 heat exchanger 3 Bulkhead 3A External surface (1st wall surface) 3B Inner surface (second wall) 4 grooves 5 Fins 7 Pin-shaped fins 9 shells 11 Side circumference (side circumference) 13 Bottom (Bottom) 17 Side (first part) 17A Outer edge (outer edge) 19 Base (second part) 21 Heat transfer surface 25 groove

Claims

1. A heat exchanger having a partition wall that separates two fluids of different temperatures, a first wall surface of the partition wall, which is a surface that comes into contact with one of the two fluids having a lower heat transfer coefficient, is formed with a plurality of grooves having a depth of 100 μm to 400 μm in a thickness direction of the partition wall, and a plurality of plate-like fins having paired heat transfer surfaces; the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, A plurality of grooves having a depth of 100 μm to 400 μm are formed in the pair of heat transfer surfaces in the thickness direction of each fin. heat exchanger.

2. 2. The heat exchanger according to claim 1, wherein a plurality of pores, each having a pore diameter of 10 nm to 30 nm, are formed in a second wall surface of the partition wall that is a surface of the partition wall that comes into contact with one of the two fluids having a higher heat transfer coefficient.

3. The partition wall forms a bottomed cylindrical body, the plurality of fins are respectively connected to a bottom surface and a side peripheral surface that constitute an outer surface of the bottomed cylinder, In a first portion of each of the fins connected to the bottom surface of the bottomed cylinder, the plurality of grooves each extend toward the bottom surface, The heat exchanger according to claim 1 or 2, wherein in the second portion of each of the fins connected to the side peripheral surface of the bottomed cylinder, the plurality of grooves each extend along the side peripheral surface.

4. The heat exchanger according to claim 3 , further comprising a shell provided to cover the outside of the plurality of fins and connected to outer edges of the plurality of fins opposite to the partition wall.

5. The heat exchanger according to claim 3 , further comprising a plurality of pin-shaped fins each protruding outward in an area of ​​the bottom surface of the bottomed cylinder where the plurality of fins are not formed.

6. The heat exchanger according to claim 1 or 2, wherein the curved portions of the plurality of fins are formed in a spiral shape.

7. The heat exchanger according to claim 1 or 2, wherein each of the fins has a cross section that tapers in a direction away from the partition wall.

8. A heat exchanger that has a partition wall that separates a gas from a liquid and performs heat exchange between the gas and the liquid, a first wall surface of the partition wall, which is a surface that comes into contact with a gas, is formed with a plurality of grooves having a depth of 100 μm to 400 μm in a thickness direction of the partition wall, and a plurality of plate-like fins having paired heat transfer surfaces; the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, A heat exchanger, wherein a plurality of grooves having a depth of 100 μm to 400 μm are formed in the pair of heat transfer surfaces in the thickness direction of each of the fins.

9. 9. The heat exchanger according to claim 8, wherein a plurality of pores each having a pore diameter of 10 nm to 30 nm are formed in a second wall surface of the partition wall that is a surface that comes into contact with a liquid.

10. A method for manufacturing a heat exchanger, comprising: The partition wall that separates two fluids at different temperatures is formed using additive manufacturing. When the partition wall is molded based on the additive manufacturing, a first wall surface of the partition wall, which is a surface that comes into contact with one of the two fluids having a lower heat transfer coefficient, is provided with a plurality of grooves having a depth of 100 μm to 400 μm in a thickness direction of the partition wall, and a plurality of plate-like fins having paired heat transfer surfaces; the partition wall and the plurality of fins are integrally molded products made of the same metal material, The plurality of fins have curved portions and are arranged at intervals in a direction intersecting the pair of heat transfer surfaces, a plurality of grooves each having a depth of 100 μm to 400 μm in the thickness direction of each fin are formed on the pair of heat transfer surfaces.

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