Heat exchanger and manufacturing method thereof

Abstract

To provide a heat exchanger capable of improving heat exchange efficiency even when there is a restriction on a material used for integrally molding a partition wall and a fin, and a method for manufacturing the same.SOLUTION: A heat exchanger 1 comprises a partition wall 3 of a bottomed cylindrical container shape that partitions two fluids having different temperatures. The partition wall 3 has a side peripheral part 11 having a cylindrical shape, and a bottom part 13 formed so as to close one opening of the side peripheral part 11. A plurality of fins 5 is formed on the outer surface of the partition wall 3 so as to be aligned in a circumferential direction of the side peripheral part 11. The fin 5 has a base part 19 that connects to an outer surface of the bottom part 13. The base parts 19 of the plurality of fins 5 all extend in a radial direction on the outer surface of the bottom part 13, and are formed so as to be aligned in the circumferential direction on the outer surface of the bottom part 13. The partition wall 3 and the plurality of fins 5 are integrally molded of the same material. A plate member 35 is made of another material having higher emissivity or heat resistance than the material of the fins 5.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger having a partition wall in the form of a cylindrical vessel with a bottom 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] In the heat exchangers described in Patent Documents 1 and 2, it is desirable that the partition walls (heat transfer tubes) separating two fluids at different temperatures and the fins are integrally molded in order to improve the heat exchange efficiency. However, depending on the shapes of the partition walls and fins, there are cases where there are restrictions on the metal materials that can be used to integrally mold the partition walls and fins, which has limited the improvement in heat exchange efficiency.

[0008] The present invention provides a heat exchanger and a manufacturing method thereof that can improve heat exchange efficiency even when there are restrictions on the materials used to integrally mold the partition walls and fins. [Means for solving the problem]

[0009] The present invention provides A heat exchanger having a partition wall in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, the partition wall has a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, a plurality of fins are formed on an outer surface of the partition wall and are arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of the fins adjacent to each other in the circumferential direction, the partition wall and the plurality of fins are integrally molded from the same material, The plate-like member is formed of a material having a higher emissivity or heat resistance than the material of the fins.

[0010] The present invention also provides A heat exchanger having a partition wall in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, the partition wall has a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, a plurality of fins are formed on an outer surface of the partition wall and are arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins are formed in parallel to one another, a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of the adjacent fins, the partition wall and the plurality of fins are integrally molded from the same material, The plate-like member is formed of a material having a higher emissivity or heat resistance than the material of the fins.

[0011] The present invention also provides a partition wall in the form of a cylindrical container with a bottom, the partition wall having a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, and separating two fluids having different temperatures; a plurality of fins formed on an outer surface of the partition wall and arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, A method for manufacturing a heat exchanger, wherein a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of the fins adjacent to each other in the circumferential direction, The partition wall and the plurality of fins are integrally molded by layer-by-layer manufacturing of powder; The plate-like members provided between the fins adjacent to each other in the circumferential direction are formed of a material having a higher emissivity or heat resistance than the material of the fins, and are fixed to the outer surface of the bottom portion. [Effects of the Invention]

[0012] According to the present invention, even if there are restrictions on the materials used to integrally mold the partition walls and fins, heat radiation (radiant heat transfer) can be increased by using plate-shaped members formed from materials with higher emissivity or heat resistance, thereby improving heat exchange efficiency. [Brief explanation of the drawings]

[0013] [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] 2 is a perspective view showing one fin formed on a partition wall of the heat exchanger of FIG. 1. FIG. [Figure 3] FIG. 2 is a partial top view of the heat exchanger of FIG. 1. [Figure 4] FIG. 2 is a perspective view of the heat exchanger of FIG. 1 with the shell removed. [Figure 5] FIG. 2 is a cross-sectional view of the fin of FIG. 1. [Figure 6] 2 is an explanatory diagram showing the detailed structure of the heat transfer surface of the fin in FIG. 1. [Figure 7] FIG. 2 is a partial bottom view of the heat exchanger of FIG. 1. [Figure 8] FIG. 2 is a perspective view of a pin-shaped fin of the heat exchanger of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0014] A heat exchanger according to an embodiment of the present invention and a method for manufacturing the same will be described below with reference to the drawings. The drawings should be viewed in the direction indicated by the reference numerals.

[0015] (Heat exchanger configuration) 1, the heat exchanger 1 mainly comprises a partition wall 3, a plurality of plate-like fins 5, a plurality of 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.

[0016] 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.

[0017] Hereinafter, for the sake of simplicity and clarity of explanation, unless otherwise specified, the terms axial direction, radial direction, and circumferential direction refer to directions centered around the cylindrical center of the side peripheral portion 11.

[0018] The partition walls 3 are integrally molded 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 material. This material may be metal, resin, or ceramic. An example of the metal is aluminum.

[0019] A plurality of fins 5 are formed in a circumferential arrangement on the outer surface 3A of the partition wall 3. As shown in FIG. 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 17 connected to the outer surface of the side periphery 11 and a base portion 19 connected to the outer surface of the bottom 13.

[0020] Each fin 5 has a pair of heat transfer surfaces 21, 21 (main heat transfer surfaces) that are arranged so as to intersect or approximately perpendicular to the circumferential direction of the side peripheral portion 11. As also shown in Fig. 3, the multiple fins 5 are arranged at intervals from each other in the circumferential direction (i.e., the direction intersecting the pair of heat transfer surfaces 21, 21) all around the circumference of the side peripheral portion 11.

[0021] 4, 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).

[0022] 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.

[0023] 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.

[0024] 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 D 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 W of the plurality of grooves 25 is preferably set to about twice the depth D (200 μm to 800 μm). Similarly, the interval L 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.

[0025] 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. The portion 19 has a protrusion 31 that protrudes downward in a side view and has a top that is approximately at a right angle.

[0026] 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.

[0027] 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 peripheral surface of the bottomed cylinder to flow along the side peripheral surface using multiple grooves 25, heat transfer at the side peripheral portion 11 of the bottomed cylinder can be promoted.

[0028] 1 and 7 , the bases 19 of the multiple fins 5 all extend radially on the outer surface of the bottom 13 of the partition wall 3. The bases 19 of the multiple fins 5 are formed side by side in the circumferential direction on the outer surface of the bottom 13 of the partition wall 3.

[0029] The multiple fins 5 include first fins 5L and second fins 5S, each having a base 19 with a different radial length. The base 19L of the first fin 5L and the base 19S of the second fin 5S are both continuous with the side portion 17 and extend radially inward from the outer peripheral edge of the bottom 13 of the partition wall 3. The radially inner end of the base 19L of the first fin 5L is located radially inward of the radially inner end of the base 19S of the second fin 5S. Therefore, the base 19L of the first fin 5L extends radially inward of the base 19S of the second fin 5S.

[0030] The first fins 5L and the second fins 5S are arranged alternately in the circumferential direction.

[0031] In this embodiment, the base 19L of the first fin 5L has a tapered shape that narrows radially inward when viewed from the bottom.

[0032] At the bottom 13 of the partition wall 3, plate-like members 35 fixed to the outer surface of the bottom 13 are provided between adjacent fins 5 in the circumferential direction. Each plate-like member 35 has a substantially rectangular plate shape.

[0033] Each plate-like member 35 is formed from another material (e.g., stainless steel) having a higher emissivity than the material (e.g., aluminum) forming the partition wall 3 and the fins 5. The multiple plate-like members 35 are fitted by press-fitting into multiple mounting grooves 37 formed on the outer surface 3A of the bottom 13 of the partition wall 3. In addition to or instead of fixation by press-fitting, the plate-like members 35 may be fixed to the outer surface of the bottom 13 of the partition wall 3 with a heat-resistant adhesive, by welding, or by caulking. The material forming the plate-like members 35 is not limited to stainless steel, and may be any material having an emissivity at least higher than that of the material forming the partition wall 3 and the fins 5.

[0034] As a result, even if there are restrictions on the materials used to integrally mold the partition wall 3 and the fins 5, the plate-like member 35 made of a material with a higher emissivity can increase thermal radiation (radiant heat transfer), thereby improving heat exchange efficiency.

[0035] Furthermore, by fixing the plate-like member 35 to the outer surface of the bottom 13 of the partition wall 3 using heat-resistant adhesive or rivets, the plate-like member 35 can be firmly fixed to the outer surface of the bottom 13 of the partition wall 3 even if the material used to make the plate-like member 35 has a melting point that is significantly different from the melting point of the material making up the partition wall 3 and the fins 5.

[0036] When viewed from the bottom, each plate-like member 35 extends radially between adjacent first fins 5L in the circumferential direction and radially inward of the radially inner end of the second fin 5S, along an imaginary straight line extending radially from the radially inner end of the second fin 5S toward the center.

[0037] Therefore, the number of plate-like members 35 provided is the same as the number of second fins 5S.

[0038] Each plate-like member 35 extends radially from the radially inner side of the radially inner end of base 19S of second fin 5S to approximately the same position as the radially inner end of base 19L of first fin 5L.

[0039] This allows the plate-like members 35, which are made of a material with a higher emissivity, to be located closer to the center of the bottom 13, thereby improving the heat exchange efficiency of the heat exchanger 1. In addition, the plate-like members 35 are arranged to suppress an increase in loss when the second fluid 15 flows from the center to the outside in the radial direction between adjacent fins 5 in the circumferential direction, so the heat exchange efficiency of the heat exchanger 1 is further improved.

[0040] It should be noted that each plate-like member 35 does not abut against the fins 5 (first fins 5L and second fins 5S).

[0041] This allows radiant heat from the plate-like members 35 to be transferred to the fins 5 while maintaining thermal conductivity inside the fins 5. Furthermore, each plate-like member 35 has a thickness thinner than the fins 5. Therefore, the plate-like members 35 do not block the passage of the second fluid 15, and can cause the fins 5 to receive the thermal energy of the gas by radiating heat. As a result, the fins 5 can receive a large amount of heat from the gas, with an apparent increase in the heat transfer coefficient compared to the amount of heat received by heat transfer with the second fluid 15 with which they are in physical contact.

[0042] Each plate-like member 35 does not necessarily need to be made of a material with a higher emissivity than the material constituting the partition walls 3 and fins 5; it may be made of a material with a higher heat resistance than the material constituting the partition walls 3 and fins 5. This is because the partition walls 3 and fins 5 do not reach high temperatures due to heat transfer to the surrounding low-temperature areas, whereas the thin plate-like member 35 is exposed to the high-temperature gas and does not lose heat through thermal conduction, resulting in a high temperature close to the temperature of the second fluid 15 (enough to become red-hot). Because the amount of radiant heat emitted is proportional to the fourth power of temperature (Kelvin temperature), even a plate-like member with a relatively low emissivity will emit a large amount of radiant heat at high temperatures. Therefore, the plate-like member 35 must have high heat resistance so that it will not melt even at high temperatures. The radiation effect is clearly evident when the temperature of the second fluid is high (400°C to 500°C or higher).

[0043] Furthermore, at the bottom 13 of the partition wall 3, the radially inner ends of the bases 19L of the multiple first fins 5L and the radially inner ends of the multiple plate-shaped members 35 define an approximately circular area in which multiple pin-shaped fins 7 are arranged.

[0044] 8, each pin-shaped fin 7 has a tapered cylindrical (or conical) shape. A plurality of ridges 41 extending in the longitudinal direction (projecting direction) are formed on the circumferential surface of each pin-shaped fin 7. The ridges 41 are arranged at predetermined intervals in the circumferential direction.

[0045] 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.

[0046] An unsealed anodized aluminum coating is formed on the inner surface 3B of the partition wall 3. The anodized aluminum coating has a plurality of pores, each having a pore diameter of 10 nm to 30 nm. As a result, 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 anodized aluminum coating may be omitted. Alternatively, the anodized aluminum coating may be formed only on a portion of the inner surface 3B of the partition wall 3 (for example, the inner surface 13B of the bottom 13).

[0047] 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.

[0048] 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.

[0049] (Heat exchanger manufacturing) Next, the manufacturing method of the heat exchanger 1 having the above-described configuration will be described. The partition walls 3, the plurality of fins 5, and the plurality of pin-shaped fins 7 of the heat exchanger 1 are integrally formed by additive manufacturing of powder material using a known 3D printing technology. The processing method used for additive manufacturing is not particularly limited as long as it can realize the structure described above. For example, the heat exchanger 1 is formed by simultaneously irradiating the part to be formed with metal powder and a laser (or electron beam) and stacking the molten metal powder into the above-described shape.

[0050] 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 material different from the 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.

[0051] 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).

[0052] Then, multiple plate-like members 35 are formed from a material having a higher emissivity than the material constituting the partition 3 and the fins 5, and are pressed into multiple mounting grooves 37 formed on the outer surface 3A of the bottom 13 of the partition 3, and fixed to the outer surface of the bottom 13 of the partition 3.

[0053] In this way, by additive manufacturing of material powder, the partition 3 and multiple fins 5 are molded into a single unit, and the plate-shaped member 35 is formed from a material having a higher emissivity than the material constituting the partition 3 and fins 5 and fixed to the outer surface of the bottom 13, the heat exchange efficiency can be improved even if there are restrictions on the material used to mold the partition 3 and fins 5 into a single unit.

[0054] (Use of heat exchanger) 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).

[0055] 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.

[0056] 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.

[0057] For example, the first fluid and the second fluid do not need to be a combination of a liquid and a gas, and any combination of fluids (for example, a combination of liquids or gases) can be used. Furthermore, the heat exchanger 1 only needs to use at least two fluids, and may perform heat exchange using three or more fluids.

[0058] 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 and fins. 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.

[0059] Furthermore, in the above-described embodiment, the bases 19 of the fins 5 are arranged radially on the bottom 13, but this is not limiting and they may be arranged in parallel. Note that "parallel" does not necessarily mean parallel, but means arranged in approximately the same direction. Similarly to the case of radial fins, when a thin plate-like member 35 with high emissivity or heat resistance is arranged between the bases 19 of the parallel-arranged fins 5, the amount of heat transferred from the second fluid 15 to the fins 5 increases due to radiant heat emitted from the heated plate-like member 35, and the apparent heat transfer coefficient improves.

[0060] 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.

[0061] (1) A heat exchanger (heat exchanger 1) having a partition (partition 3) in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, The partition wall has a cylindrical side peripheral portion (side peripheral portion 11) and a bottom portion (bottom portion 13) formed to close one opening of the side peripheral portion, A plurality of fins (fins 5) are formed on the outer surface of the partition wall and arranged in a circumferential direction around the cylinder center of the side peripheral portion, Each of the fins has a base (base 19) that connects to the outer surface of the bottom, The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, A plate-shaped member (plate-shaped member 35) fixed to the outer surface of the bottom is provided between the base portions of the fins adjacent to each other in the circumferential direction, the partition wall and the plurality of fins are integrally molded from the same material, A heat exchanger, wherein the plate-like member is formed of a material having a higher emissivity than the material of the fins.

[0062] According to (1), even if there are restrictions on the materials used to integrally mold the partition wall and fins, the heat radiation (radiant heat transfer) can be increased by using plate-shaped members made of materials with higher emissivity, thereby improving the heat exchange efficiency.

[0063] (2) The heat exchanger according to (1), The plate-shaped member is fixed to the outer surface of the bottom with a heat-resistant adhesive.

[0064] According to (2), the plate-shaped member is fixed to the outer surface of the bottom with heat-resistant adhesive, so that the plate-shaped member can be firmly fixed to the outer surface of the bottom even if the material used to make the plate-shaped member has a melting point significantly different from the melting point of the material making up the fin.

[0065] (3) The heat exchanger according to (1) or (2), The plurality of fins include a first fin (a first fin 5L) and a second fin (a second fin 5S), a radially inner end portion of the base of the first fin is located radially more inward than a radially inner end portion of the base of the second fin, the first fins and the second fins are arranged alternately in the circumferential direction, The plate-shaped member extends radially between the first fins adjacent to each other in the circumferential direction and radially inward of the radially inner end of the second fin along an imaginary straight line extending radially from the radially inner end of the second fin toward the center, in a bottom view of the heat exchanger.

[0066] According to (3), the plate-shaped member made of a material with a higher emissivity can be located closer to the center of the bottom, improving the heat exchange efficiency of the heat exchanger. In addition, the plate-shaped member is positioned so as to suppress an increase in loss when the fluid flows from the center to the outside in the radial direction between adjacent fins in the circumferential direction, further improving the heat exchange efficiency of the heat exchanger.

[0067] (4) A heat exchanger according to any one of (1) to (3), The plate-like member is not in contact with the fins.

[0068] According to (4), the radiant heat from the plate-like member can be transferred to the fin while maintaining the heat conduction inside the fin.

[0069] (5) A partition wall (partition wall 3) in the form of a cylindrical container with a bottom, which has a cylindrical side peripheral portion (side peripheral portion 11) and a bottom portion (bottom portion 13) formed so as to close one opening of the side peripheral portion, and separates two fluids having different temperatures; a plurality of fins (fins 5) formed on the outer surface of the partition wall and arranged in a circumferential direction around the cylinder center of the side peripheral portion, Each of the fins has a base (base 19) that connects to the outer surface of the bottom, The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, A method for manufacturing a heat exchanger (heat exchanger 1), wherein a plate-shaped member (plate-shaped member 35) fixed to an outer surface of the bottom is provided between the bases of the fins adjacent to each other in the circumferential direction, The partition wall and the plurality of fins are integrally molded by layer-by-layer manufacturing of powder; A method for manufacturing a heat exchanger, comprising forming the plate-shaped members provided between adjacent fins in the circumferential direction from a material having a higher emissivity than the material of the fins and fixing the plate-shaped members to the outer surface of the bottom.

[0070] According to (5), even if there are restrictions on the materials used to integrally mold the partition walls and fins, the heat radiation (radiant heat transfer) can be increased by using plate-shaped members made of materials with higher emissivity, thereby improving the heat exchange efficiency.

[0071] (6) A heat exchanger (heat exchanger 1) having a partition (partition 3) in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, The partition wall has a cylindrical side peripheral portion (side peripheral portion 11) and a bottom portion (bottom portion 13) formed to close one opening of the side peripheral portion, A plurality of fins (fins 5) are formed on the outer surface of the partition wall and arranged in a circumferential direction around the cylinder center of the side peripheral portion, Each of the fins has a base (base 19) that connects to the outer surface of the bottom, The base portions of the plurality of fins are formed in parallel to one another, A plate-shaped member (plate-shaped member 35) is provided between the base portions of adjacent fins and is fixed to the outer surface of the bottom portion, the partition wall and the plurality of fins are integrally molded from the same material, A heat exchanger, wherein the plate-like member is formed of a material having a higher emissivity or heat resistance than the material of the fins.

[0072] According to (6), even if there are restrictions on the materials used to integrally mold the partition walls and fins, the heat radiation (radiant heat transfer) can be increased by using plate-shaped members made of materials with higher emissivity, thereby improving the heat exchange efficiency. [Explanation of symbols]

[0073] 1 heat exchanger 3 Bulkhead 5 Fins 5L 1st fin 5S 2nd fin 11 Side circumference 13 Bottom 19 Base 35 Plate-shaped members

Claims

1. A heat exchanger having a partition wall in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, the partition wall has a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, a plurality of fins are formed on an outer surface of the partition wall and are arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of the fins adjacent to each other in the circumferential direction, the partition wall and the plurality of fins are integrally molded from the same material, A heat exchanger, wherein the plate-like member is formed of a material having a higher emissivity or heat resistance than the material of the fins.

2. 2. The heat exchanger of claim 1, A heat exchanger, wherein the plate-shaped member is pressed into a groove provided on the outer surface of the bottom, or is fixed to the outer surface of the bottom with a heat-resistant adhesive, or is welded to the outer surface of the bottom.

3. 2. The heat exchanger of claim 1, the plurality of fins include a first fin and a second fin, a radially inner end portion of the base of the first fin is located radially more inward than a radially inner end portion of the base of the second fin, the first fins and the second fins are arranged alternately in the circumferential direction, A heat exchanger in which, when viewed from the bottom, the plate-shaped member extends radially between adjacent first fins in the circumferential direction and radially inward of the radially inner end of the second fin, along an imaginary straight line extending radially from the radially inner end of the second fin toward the center.

4. 4. A heat exchanger according to any one of claims 1 to 3, The plate-like member is not in contact with the fins.

5. a partition wall in the form of a cylindrical container with a bottom, the partition wall having a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, and separating two fluids having different temperatures; a plurality of fins formed on an outer surface of the partition wall and arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins all extend on the outer surface of the bottom portion in a radial direction centered on the cylindrical center of the side peripheral portion, and are formed side by side in the circumferential direction on the outer surface of the bottom portion, A method for manufacturing a heat exchanger, wherein a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of the fins adjacent to each other in the circumferential direction, The partition wall and the plurality of fins are integrally molded by layer-by-layer manufacturing of powder; A method for manufacturing a heat exchanger, wherein the plate-shaped members provided between adjacent fins in the circumferential direction are formed from a material having a higher emissivity or heat resistance than the material of the fins and are fixed to the outer surface of the bottom.

6. A heat exchanger having a partition wall in the form of a cylindrical container with a bottom that separates two fluids of different temperatures, the partition wall has a cylindrical side peripheral portion and a bottom portion formed to close one opening of the side peripheral portion, a plurality of fins are formed on an outer surface of the partition wall and are arranged in a circumferential direction around a cylinder center of the side peripheral portion, Each of the fins has a base connected to an outer surface of the bottom portion; The base portions of the plurality of fins are formed in parallel to one another, a plate-like member fixed to an outer surface of the bottom portion is provided between the base portions of adjacent fins, the partition wall and the plurality of fins are integrally molded from the same material, A heat exchanger, wherein the plate-like member is formed of a material having a higher emissivity or heat resistance than the material of the fins.

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