JP7471104B2 - Heat exchange core, heat exchanger, and method for manufacturing heat exchange core - Google Patents

Description

The present disclosure relates to a heat exchange core, a heat exchanger, and a method for manufacturing a heat exchange core.

For example, a cylindrical heat exchanger is known in which a group of flow paths is formed inside a cylindrical casing. Generally, in a cylindrical heat exchanger, in order to exchange heat between a first fluid and a second fluid, either the first fluid or the second fluid flows in and out of the axial end of a cylindrical casing, and the other fluid flows in and out of the side of the casing along the radial direction (see, for example, Patent Document 1).

JP 2018-519490 A

In a cylindrical heat exchanger as described above, the flow of fluid that flows into the casing along the radial direction is redirected to the axial direction, and the flow of fluid that flows along the axial direction inside the casing is redirected to the radial direction. As a result, there is a risk that the flow rate of the fluid flowing inside the casing will differ depending on the circumferential or radial position, and there is a risk that the heat exchange efficiency will decrease due to such flow rate differences. In order to suppress such flow rate differences, it is desirable to secure a certain amount of space for redirecting the direction of the fluid flow. For this reason, it has been difficult to miniaturize a cylindrical heat exchanger while maintaining a relatively high heat exchange efficiency.

In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a heat exchange core that can be miniaturized while maintaining a relatively high heat exchange efficiency.

(1) At least one embodiment of the heat exchange core of the present disclosure comprises:
a core body including a plurality of axial flow passages extending along an axial direction;
a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages,
The header flow path is
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from each of the radial flow paths and each communicating with one or more of the axial flow paths;
Including,
Each of the radial flow passages has a flow passage area at a second position that is radially inward from the first position that is smaller than the flow passage area at the first position.

(2) At least one embodiment of the heat exchange core according to the present disclosure comprises:
a core body including a plurality of axial flow passages extending along an axial direction;
a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages,
The header flow path is
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from each of the radial flow paths and each communicating with one or more of the axial flow paths;
Including,
At least one opening is formed in the outer peripheral surface of the heat exchange core in the header portion by the at least one radial flow passage,
An opening dimension of each of the openings along the axial direction is equal to or greater than one time a opening dimension of each of the openings along the circumferential direction.

(3) At least one embodiment of the heat exchanger according to the present disclosure comprises:
A heat exchange core having the configuration of (1) or (2) above;
a casing that houses the heat exchange core;
Equipped with.

(4) A method for manufacturing a heat exchange core according to at least one embodiment of the present disclosure includes the steps of:
1. A method for manufacturing a heat exchange core, comprising the steps of:
forming a core body portion including a plurality of axial flow passages extending along an axial direction by additive manufacturing;
and forming a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages by additive manufacturing.
The step of forming the header portion includes:
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from any one of the radial flow paths and each communicating with one or more of the axial flow paths;
forming the header flow passage so as to include
The step of forming the header portion forms each of the radial flow paths such that a flow path area at a second position radially inward from the first position is smaller than a flow path area at the first position.

(5) A method for manufacturing a heat exchange core according to at least one embodiment of the present disclosure includes the steps of:
1. A method for manufacturing a heat exchange core, comprising the steps of:
forming a core body portion including a plurality of axial flow passages extending along an axial direction by additive manufacturing;
and forming a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages by additive manufacturing.
The step of forming the header portion includes:
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from any one of the radial flow paths and each communicating with one or more of the axial flow paths;
forming the header flow passage so as to include
The step of forming the header portion includes:
The header portion is formed such that at least one opening is formed by the at least one radial flow path on an outer circumferential surface of the heat exchange core in the header portion;
The header portion is formed so that an opening dimension of each of the openings along the axial direction is at least one time a opening dimension of each of the openings along the circumferential direction.

According to at least one embodiment of the present disclosure, the heat exchange core can be made smaller while still maintaining a relatively high heat exchange efficiency.

FIG. 2 is an exploded perspective view of a heat exchange core and casing of a heat exchanger according to some embodiments. 2 is a partial cross-sectional view showing a casing of the heat exchanger shown in FIG. 1 and a heat exchange core housed in the casing; 3 is a cross-sectional view taken along line IIIa-IIIa in FIG. 2 (first cross-section of the heat exchange core), showing the first and second groups of flow passages. 3B is a partially enlarged view of FIG. 3A. In the figures other than this figure, the partition wall (W2) is omitted. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 2 (second cross-section of the heat exchange core). Fig. 7 is a cross-sectional view taken along line VV in Figs. 2 and 6 (third cross-section of the heat exchange core). FIG. 2 is a schematic diagram showing the flow of a first fluid and a second fluid. 11 is a cross-sectional view showing a portion of a heat exchange core according to a modified example of the present disclosure. FIG. 11 is a schematic diagram showing a portion of a side surface of a heat exchange core according to some embodiments near a header portion, illustrating an example of the shape of an opening portion. FIG. 11 is a schematic diagram showing a portion of a side surface of a heat exchange core in the vicinity of a header portion according to some embodiments, illustrating another example of the shape of an opening portion. 5 is a schematic diagram for explaining a change in flow path area of a radial flow path with respect to a change in radial position. FIG. 5 is a schematic diagram for explaining a change in flow path area of a radial flow path with respect to a change in radial position. FIG. 1 is a flow chart illustrating process steps in a method for manufacturing a heat exchange core according to some embodiments.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.
For example, expressions expressing relative or absolute configuration, such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""center,""concentric," or "coaxial," not only express such a configuration strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained.
For example, expressions indicating that things are in an equal state, such as "identical,""equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained.
For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained.
On the other hand, the expressions "comprise,""include,""have,""includes," or "have" of one element are not exclusive expressions excluding the presence of other elements.

(General configuration of heat exchanger)
As shown in FIGS. 1 and 2 , a heat exchanger 1 according to some embodiments includes a heat exchange core 10 and a casing 20 that houses the heat exchange core 10 .
The heat exchanger 1 according to some embodiments can be incorporated in a chemical plant such as a gas turbine or a _CO2 recovery device, or in an apparatus (not shown) such as an air conditioner or a freezer, and exchanges heat between a first fluid and a second fluid, for example. For example, the temperature of the first fluid is relatively high and the temperature of the second fluid is relatively low. Conversely, the temperature of the first fluid may be relatively low and the temperature of the second fluid may be relatively high.

(Configuration of heat exchange core)
The heat exchange core 10 according to some embodiments includes a core body portion 13, and header portions 11A, 11B adjacent to one and the other axial end portions of the core body portion 13. For ease of explanation, the header portion 11A adjacent to one axial end portion of the core body portion 13 is also referred to as the first header portion 11A, and the header portion 11B adjacent to the other axial end portion is also referred to as the second header portion 11B.

Fig. 3 is a cross-sectional view taken along line IIIa-IIIa in Fig. 2. The core body portion 13 according to some embodiments includes some of the first flow passages 101, which are the axial flow passages 3 extending along the axial direction, and the second flow passages 102, as described below.
Each of the header sections 11A, 11B according to some embodiments has a header flow passage 6 that communicates with a plurality of axial flow passages 3, as described in detail later (see FIG. 6).

As shown in FIGS. 1 and 3A, the heat exchange core 10 according to some embodiments includes a first flow passage group G1 and a second flow passage group G2 that are generally arranged concentrically.
The heat exchanger 1 according to some embodiments includes a first cross section C1 shown in FIG. 3A, a second cross section C2 shown in FIG. 4, and a third cross section C3 shown in FIG. 5. All of these cross sections C1 to C3 have a circular shape. The overall outer shape of the heat exchange core 10 is formed in a cylindrical shape. The heat exchange core 10 includes a partition wall (first partition wall) W1 that is concentrically arranged to separate the first flow passage group G1 and the second flow passage group G2, and a side wall W0 that is arranged on the outermost periphery of the heat exchange core 10.

The heat exchange core 10 is given a symmetrical shape not only in its external shape but also overall with respect to the center of the cross sections C1 to C3, i.e., the central axis (axis line AX) of the heat exchange core 10, which has a cylindrical shape, which not only contributes to uniform stress distribution but also to uniform heat exchange efficiency.

In the heat exchanger 1 according to some embodiments, the first flow passage group G1 corresponds to the first fluid, and the second flow passage group G2 corresponds to the second fluid. In each figure, the first flow passage group G1 is indicated by a hatched pattern.
The second flow passage group G2 according to some embodiments extends from one end 10A (FIG. 1) to the other end 10B (FIG. 1) in the axial direction D1 of the heat exchange core 10. The axial direction D1 is perpendicular to the transverse planes C1-C3. That is, in some embodiments, the second flow passages 102 are included in the axial flow passage 3.
In each figure, the flow of the first fluid is indicated by a solid arrow, and the flow of the second fluid is indicated by a dashed arrow.

In some embodiments, the first flow paths 101 constituting the first flow path group G1 are arranged in an annular shape in the first cross section C1 shown in Fig. 3A. The second flow paths 102 constituting the second flow path group G2 are arranged in a similar manner. In some embodiments, the first fluid flowing through the first flow path group G1 and the second fluid flowing through the second flow path group G2 transfer heat by indirectly contacting each other via a first partition wall W1 shown by a thick line in Fig. 3A.

As shown in FIG. 3A , it is preferable that a plurality of first flow paths 101 and a plurality of second flow paths 102 are alternately stacked in the radial direction of the heat exchange core 10, for example, over several tens of layers.
The first flow passages 101 and the second flow passages 102 are preferably arranged over the entire radial direction of the heat exchange core 10, that is, up to the vicinity of the axis of the heat exchange core 10, that is, up to the vicinity of the axis line AX. In Fig. 3A, Fig. 3B, Fig. 4, and Fig. 5, only a part of the first flow passages 101 and a part of the second flow passages 102 are shown. The remaining first flow passages 101 and second flow passages 102 in the region indicated by "..." are omitted from the illustration.
As in this embodiment, the first flow passages 101 and the second flow passages 102 are arranged over the entire radial direction of the heat exchange core 10, so that the entire heat exchange core 10 can contribute to heat exchange.

In some embodiments, the heat exchange core 10 may have a constant cross-sectional shape corresponding to the first transverse cross section C1 (FIG. 3A) over the range between line IV-IV and line IVx-IVx shown in FIG. 2. In this range, that is, over the range from the vicinity of one end 10A of the heat exchange core 10 to the vicinity of the other end 10B, in this embodiment, the first fluid and the second fluid flow in opposite directions along the axial direction D1. In other words, the first fluid and the second fluid flow in opposite directions (completely counterflow) over almost the entire axial direction D1 of the heat exchange core 10 except for both ends.
The first and second fluids may flow in the same direction along the axial direction D1, in which case the first and second fluids flow in parallel.

The heat exchange core 10 in some embodiments is given appropriate axial and radial dimensions D1, flow passage cross-sectional area, number of layers of flow passages 101 and 102, etc., taking into account the required heat exchange capacity, stress, etc.

3B , each of the first flow paths 101 and each of the second flow paths 102 is preferably divided into a plurality of sections S by a partition wall W2 in the circumferential direction D2 of the heat exchange core 10. By providing the partition wall W2, it is possible to improve rigidity and strength, particularly in the radial direction, against fluid pressure.
In addition, by dividing the first flow path 101 and the second flow path 102 into sections S by the partition wall W2, the surface area of the flow path that comes into contact with the fluid is increased, thereby improving the heat transfer efficiency.

The sections S are preferably arranged around the entire circumference of the heat exchange core 10 with equal flow path diameters. Furthermore, it is preferable that all sections S from the outermost circumference to the axis of the heat exchange core 10 are given equal flow path diameters. In this way, the flow conditions such as friction loss are made uniform in all sections S, making it possible to make the heat transfer coefficient uniform for all sections S, and the stress acting on the heat exchange core 10 is uniformly distributed throughout the entire in-plane direction of the cross section of the heat exchange core 10, thereby making it possible to make the stress uniform.

The term "channel diameter" in this specification corresponds to the equivalent diameter D given by the following formula (1).
D = 4A / L ... (1)
A: Cross-sectional area of section S
L: Length (perimeter) of the section S in the circumferential direction D2
Since the heat transfer coefficient corresponds to the inverse of the flow path diameter, it is preferable to give an appropriate flow path diameter to the section S based on this.

The heat exchange core 10 according to some embodiments can be integrally molded, including the partition wall W2, by additive manufacturing or the like using a metal material, such as stainless steel or aluminum alloy, that has properties suitable for fluids. By additive manufacturing, for example, a molded product having a laminated two-dimensional shape can be obtained by repeating the steps of supplying metal powder to a molding area in an apparatus, irradiating a laser beam or an electron beam based on two-dimensional data showing a cross section of a three-dimensional shape, melting the metal powder, and solidifying the metal powder.
In some embodiments, the thickness of the wall W1, etc. in the heat exchange core 10 obtained by additive manufacturing using a metal material is, for example, 0.3 to 3 mm.
The heat exchange core 10 according to some embodiments is manufactured through a step of forming the first flow passage group G1 and the second flow passage group G2 by additive manufacturing using a metal material. The molded product obtained by the molding step by additive manufacturing can be polished as necessary. The manufacturing method of the heat exchange core 10 according to some embodiments will be described in detail later.
The heat exchange core 10 according to some embodiments can be molded integrally by cutting or the like, without being limited to additive manufacturing.

The heat exchange core 10 according to some embodiments may be configured by combining a plurality of first partition walls W1 formed by bending a metal plate material, but is preferably formed as an integral unit. When the heat exchange core 10 is formed as an integral unit, the heat exchange core 10 does not require a gasket to prevent leakage of fluid between the members.
When using a gasket, it is necessary to give the gasket an appropriate amount of elastic deformation to reliably seal between the components. This requires maintenance such as disassembling the components of the heat exchange core and refastening the gasket between the components to prevent fluid leakage. Maintenance is particularly important for gaskets, as there may be changes in the amount of deformation due to gasket tolerances, assembly tolerances, changes in fluid pressure, changes in the gasket over time, or damage to the gasket due to thermal stress.
In contrast, the integrally molded heat exchange core 10 according to some embodiments does not include a gasket, which can significantly reduce the maintenance work.

(Casing and Header)
The casing 20 according to some embodiments is formed into a generally cylindrical shape as shown in Fig. 1 and Fig. 2. The casing 20 is formed using, for example, stainless steel, an aluminum alloy, or the like, which has properties suitable for the fluid.
The casing 20 according to some embodiments includes a casing body 21 having an inner diameter corresponding to the outer diameter of the heat exchange core 10 and a circular cross section, and large diameter portions 22 whose diameters are enlarged relative to the casing body 21. The large diameter portions 22 are provided on both ends of the casing body 21 in the axial direction D1. These large diameter portions 22 function as a first inlet header 221 and a first outlet header 222.
These headers 221, 222 each have annular internal spaces 221A, 222A (FIG. 2) as communicating spaces around the side wall W0 of the heat exchange core 10.

In some embodiments, the first inlet header 221 is provided with an inlet port 22A through which the first fluid flows in from the outside. In some embodiments, the first outlet header 222 is provided with an outlet port 22B through which the first fluid flows out to the outside.
In some embodiments, the inlet port 22A is not limited to one, but may be provided at a plurality of locations in the circumferential direction D2. For example, two inlet ports 22A may be disposed point-symmetrically with respect to the center of the second transverse plane C2. The same applies to the outlet port 22B.

In some embodiments, the internal spaces 221A, 222A of the headers 221, 222 each have a sufficient flow passage cross-sectional area in a direction intersecting the circumferential direction D2, so that the resistance of the first fluid in the internal spaces 221A, 222A is smaller than the resistance of the first fluid in the multiple radial flow passages 61 described below. This makes it easier for the first fluid to flow evenly from the first inlet header 221 into the radial flow passages 61, and when the first fluid flows out of the first outlet header 222 through the radial flow passages 61, the variation in the flow rate of each radial flow passage 61 is suppressed.

In some embodiments, one end 10A of the casing 20 in the axial direction D1 is provided with a second inlet header 31. The other end 10B of the casing 20 in the axial direction D1 is provided with a second outlet header 32.
In some embodiments, the gap between the flange 31A of the second inlet header 31 and the flange 231 of the casing 20 is sealed by an annular seal member (not shown). The same applies to the gap between the flange 32A of the second outlet header 32 and the flange 232 of the casing 20.

In some embodiments, the first flow path group G1 is connected to the interior of the first inlet header 221 and the interior of the first outlet header 222.
In some embodiments, the second flow passage group G2 is connected to the interior of the second inlet header 31 and the interior of the second outlet header 32. A starting end of each of the second flow passages 102 opens inside the second inlet header 31. A terminal end of each of the second flow passages 102 opens inside the second outlet header 32.

The directions in which the first fluid and the second fluid flow into and out of the heat exchange core 10 can be determined appropriately taking into consideration the layout of the inflow and outflow paths and interference between the headers of the first fluid and the second fluid, etc.
For example, contrary to the above description, the first fluid may be caused to flow through the second flow passage group G2, and the second fluid may be caused to flow through the first flow passage group G1 .

(Definition of approximately circular, approximately annular, and approximately concentric)
In some embodiments, the cross section of the casing 20 does not necessarily have to be strictly circular, but may be "approximately circular" that can be considered to be roughly circular. Note that the "circular shape" is allowed to have a tolerance with respect to a perfect circle.
The "approximately circular shape" includes, for example, a polygonal shape with many vertices (e.g., 10 to 20-sided) and a shape that is n-fold rotationally symmetric, where n is, for example, 10 to 20. In addition, a shape in which an arc continues over almost the entire circumferential direction D2 and in which there are projections and recesses on part of the circumference is also considered to be included in the "approximately circular shape".

As above, the cross sections C1 to C3 of the heat exchange core 10 according to some embodiments do not need to be strictly circular, but may be "approximately circular". In this case, in the first cross section C1, it is sufficient that the first flow passage 101 and the second flow passage 102 are formed in an "approximately circular" shape that can be considered to be roughly circular, and similarly, it is sufficient that the first flow passage group G1 and the second flow passage group G2 are arranged in an approximately concentric shape that can be considered to be roughly concentric. "Approximately circular" has the same meaning as the approximately circular shape described above.

7, in order to increase the heat transfer area, the first partition W1 may be provided with a plurality of protrusions 103 rising from the first partition W1 toward at least one of the first flow passage 101 and the second flow passage 102. From the viewpoint of suppressing pressure loss from a radial flow passage 61 described later to the first flow passage 101 and allowing the first fluid to smoothly flow in and out of the first flow passage 101 from the first flow passage 101 to the radial flow passage 61, it is preferable that the protrusions 103 are provided on the first partition W1 so as to avoid both ends of the first flow passage 101 in the axial direction D1.
The heat exchange core 10 with the protrusions 103 can be integrally formed by an additive manufacturing process.

For "concentric" circular shapes of different diameters arranged concentrically, tolerances are allowed for the coincidence of the centers of the circles (concentricity). In other words, "approximately concentric" includes circular shapes arranged approximately concentrically. Each circular element that makes up the concentric circles is considered to have the same meaning as the approximately circular shape described above. Multiple polygonal shapes can be arranged "approximately concentric" by aligning their centers, or by aligning the centers of a polygonal shape and a rotationally symmetric shape.

It is most preferable from the standpoint of uniformity of stress, heat transfer area, and flow condition if the cross-sections of the casing 20 and the heat exchange core 10 are circular, the cross-sections of the first flow path 101 and the second flow path 102 are annular, and the first flow path group G1 and the second flow path group G2 are arranged concentrically.
However, even if the cross-section of the casing 20 or the heat exchange core 10 is approximately circular, the first flow path 101 and the second flow path 102 are approximately annular in the first cross-section C1, or the first flow path group G1 and the second flow path group G2 are arranged approximately concentrically as a whole, it is possible to obtain effects equivalent to those of this embodiment described below.

(Explanation regarding the second cross section)
Hereinafter, an outline of the second cross section C2 according to some embodiments and the radial flow passages 61 and the circumferential flow passages 66 that appear in the second cross section C2 will be described. Note that the details of the radial flow passages 61 according to some embodiments will be described separately.
As shown in Fig. 4, which corresponds to the cross section taken along line IV-IV in Fig. 2, the heat exchange core 10 is formed with radial flow passages 61 that cross the first flow passage group G1 and the second flow passage group G2 and communicate only with the first flow passage group G1. The radial flow passages 61 extend in the radial direction of the heat exchange core 10 in the second cross section C2 shown in Fig. 4, and communicate with the internal space 221A of the first inlet header 221 as shown in Fig. 2. The radial flow passages 61 penetrate the side wall W0 in the thickness direction as shown in Figs. 1 and 2.

In some embodiments, the multiple first flow paths 101 extend in the axial direction within the heat exchange core 10 and communicate with the radial flow paths 61 on one side and the other side in the axial direction. In some embodiments, the axial flow paths 3 include the multiple first flow paths 101 arranged in the core body portion 13. In some embodiments, as described later, the multiple first flow paths 101 arranged in the header portions 11A and 11B are also referred to as circumferential flow paths 66. In some embodiments, the circumferential flow paths 66 are arranged in layers alternately with the second flow paths 102 along the radial direction.

The cross-sectional view along line IVx-IVx in FIG. 2 is omitted, but is similar to FIG. 4. The cross-section along line IVx-IVx in FIG. 2 also corresponds to the second cross-section C2. The cross-section along line IVx-IVx is referred to as the second cross-section C2x. The radial flow passage 61 located in the second cross-section C2x is connected to the internal space 222A of the first outlet header 222.

In some embodiments, at least one radial flow passage 61 is provided in each of the second transverse planes C2 and C2x. In each of the second transverse planes C2 and C2x, a plurality of radial flow passages 61 (e.g., eight in the embodiment shown in FIG. 4) may be distributed in the circumferential direction D2. By distributing a plurality of radial flow passages 61 in the circumferential direction D2, the rigidity and strength of the heat exchange core 10 can be uniformed in the circumferential direction D2, and the flow state of the first fluid in the circumferential direction D2 can also be uniformed.
The greater the number of radial flow passages 61, the easier it is to equalize the flow rate of the first fluid flowing through each radial flow passage 61. In this way, heat is sufficiently exchanged between the first fluid, which flows evenly throughout the entire circumferential direction D2, and the second fluid. In consideration of this, it is preferable that four or more radial flow passages 61 are distributed in each of the second transverse cross sections C2 and C2x. However, it is also acceptable for the number of radial flow passages 61 to be three or less (including one) in each of the second transverse cross sections C2 and C2x.

In some embodiments, in order to contribute to uniformity of the flow rate of the first fluid flowing through each radial flow passage 61, it is preferable that the multiple radial flow passages 61 are distributed at equal intervals in the circumferential direction D2. In other words, it is preferable that the heat exchange core 10 is formed symmetrically with respect to the center of the cross section even in the second cross sections C2 and C2x.

The shape of the opening in the side wall W0 of each radial flow passage 61 is rectangular in the example shown in Figures 1 and 2. The openings of the radial flow passages 61 are distributed in the circumferential direction D2 in the side wall W0.

In addition, as described above, in order to contribute to uniformity of the flow rate of the first fluid flowing through each radial flow passage 61, it is preferable that the phases of the inlet port 22A and the radial flow passage 61 are shifted from each other, that is, the inlet port 22A and the radial flow passage 61 are arranged at different positions in the circumferential direction D2. When the phase of the inlet port 22A and the phase of the radial flow passage 61 are shifted, it is possible to more reliably prevent bias in the flow rate of the first fluid flowing through each radial flow passage 61 compared to when they are not shifted (they are at the same position in the circumferential direction D2).

In some embodiments, each radial flow passage 61 includes a set of tubular transverse walls W3 located in the region of the second flow passages 102. The radial flow passages 61 are separated from the second flow passage group G2 by the transverse walls W3. The transverse walls W3 are provided integrally with the first partition walls W1 between the first partition walls W1, W1 adjacent in the radial direction of the heat exchange core 10. Each first flow passage 101 communicates with the inside of the transverse walls W3.
All of the first flow paths 101, from the first flow paths 101 located on the outer periphery of the heat exchange core 10 to the first flow paths not shown located near the axis of the heat exchange core 10, are connected to the internal spaces 221A, 222A of the first inlet header 221 and the first outlet header 222 respectively through a plurality of radial flow paths 61 extending radially from near the axis of the heat exchange core 10, and are also connected to the outside of the heat exchange core 10.

(Explanation of the third cross section)
FIG. 5, which corresponds to the cross section taken along line VV in FIGS. 2 and 6, shows a third transverse cross section C3 located outside the second transverse cross section C2 in the axial direction D1.
In some embodiments, the first flow passage group G1 communicating with the above-mentioned radial flow passage 61 is provided with a blocking wall W4 located outside the second transverse plane C2 in the axial direction D1 as shown in Fig. 6. The first fluid flowing through the first flow passage group G1 does not flow in the axial direction D1 beyond the blocking wall W4 intersecting with the axial direction D1. The blocking wall W4 blocks the space between the adjacent first partition walls W1, W1.

In some embodiments, the first flow passage group G1 is blocked in the third cross-section C3 ( FIG. 5 ) by the blocking wall W4, so that only the second flow passage group G2 is present in the third cross-section C3, and the first flow passage group G1 is not present in the region shown by the grid pattern in FIG. 5 due to the presence of the blocking wall W4.
The second flow passage group G2 is open to a second inlet header 31 and a second outlet header 32 at the ends of the heat exchange core 10 .

The cross-sectional view of line Vx-Vx in Fig. 2 is omitted, but is similar to Fig. 5. In some embodiments, the cross section corresponding to line Vx-Vx in Fig. 2 corresponds to a third cross section C3x located outside the second cross section C2x in the axial direction D1. The cross section corresponding to line Vx-Vx is referred to as the third cross section C3x.
In some embodiments, as shown in Fig. 6, the first flow passage group G1 is blocked in the third cross section C3x by a blocking wall W4, so that only the second flow passage group G2 exists in the third cross section C3x.

(Flow of the first fluid and the second fluid)
2, 4 and 6, the flows of the first and second fluids in the heat exchange core 10 will be described. FIG. 6 shows a part of the longitudinal cross section of the heat exchange core 10.
In some embodiments, as shown by dashed arrows in Fig. 6, the second fluid that has flowed into the second inlet header 31 through an inlet port (not shown) flows into each starting end of the second flow passages 102 of the second flow passage group G2. At this time, since the second flow passage group G2 is formed symmetrically with respect to the center of the third transverse section C3, i.e., the axis line AX, the second fluid flows uniformly into each of the second flow passages 102 throughout the entire circumferential direction D2 and flows through the second flow passages 102 in the axial direction D1. The second fluid flows out from the end of the second flow passage 102 into the second outlet header 32, and further flows out to the outside of the heat exchanger 1 through an outlet port (not shown).

In some embodiments, as shown by the solid arrows in Figure 6, the first fluid that flows into the inside of the first inlet header 221 from the inlet port 22A flows evenly in the circumferential direction D2 from the first inlet header 221 to the first flow path group G1 through the radial flow paths 61 that open into the side wall W0.
At this time, the first fluid is distributed from the first inlet header 221 to each of the multiple radial flow paths 61 without being biased toward some of the radial flow paths 61 close to the inlet port 22A, and in each radial flow path 61, the first fluid passes toward the radial inside of the heat exchange core 10, inside the transverse wall W3 shown by the dotted line in Figure 6, and is distributed to each first flow path 101.

Thereafter, based on the symmetry of the heat exchange core 10 in the second cross-sectional plane C2 where the radial flow passages 61 are located, the flow rate of the first fluid flowing in the axial direction D1 through the first flow passage 101 is maintained uniform throughout the entire circumferential direction D2. Therefore, heat can be sufficiently exchanged between the second fluid flowing in the second flow passage 102 and the first fluid flowing in the first flow passage 101 over the entire range in which the second cross-sectional plane C2 is continuous, under countercurrents that tend to ensure a large temperature difference between the flow passages 101 and 102.
When the first fluid flows in the axial direction D1 in each of the first flow paths 101 and reaches the terminal end of the first flow path 101, the flow direction is changed from the axial direction D1 to the radial direction, and in each of the radial flow paths 61 arranged radially from the axis of the heat exchange core 10, the first fluid passes through the inside of the transverse wall W3, merges, and flows through the radial flow paths 61 toward the radial outside of the heat exchange core 10. Then, the first fluid that flows out from the radial flow paths 61 to the inside of the first outlet header 222 flows out from the outlet port 22B to the outside of the heat exchanger 1.

(Major Effects of the Heat Exchanger of the Embodiment)
According to the heat exchanger 1 of several embodiments described above, not only does the casing 20 have a symmetrical shape with respect to the axis, but based on the configuration of the heat exchange core 10 in which the first flow path group G1 and the second flow path group G2 are symmetrically stacked concentrically, stress acting due to fluid pressure, etc. can be uniformly distributed throughout the heat exchange core 10, while ensuring a large heat transfer area between the first fluid and the second fluid, and efficient heat exchange can be performed throughout the entire heat exchange core 10 through which the first fluid and the second fluid flow evenly.
As a result, damage to the heat exchange core 10 can be prevented in advance, improving reliability, and the same heat exchange capacity can be obtained with a smaller heat exchange core 10.

(Details of radial flow passages)
The radial flow passages according to some embodiments will be described in detail below.
In addition, in some embodiments of the heat exchange core 10, the first header portion 11A and the second header portion 11B have a similar structure, so in the following description, when there is no need to particularly distinguish between the first header portion 11A and the second header portion 11B, they will be simply referred to as the header portion 11 without adding the letters A and B to the reference numerals.

(Regarding the flow area of the radial flow passage)
In the heat exchange core 10 according to some embodiments, the header flow passage 6 includes at least one radial flow passage 61 extending along the radial direction. The header flow passage 6 includes a plurality of circumferential flow passages 66 branching from each of the radial flow passages 61 and respectively communicating with one or more of the axial flow passages 3.
In each radial flow passage 61, a flow passage area Ca2 at a second position P2 radially inward from the first position P1 is smaller than a flow passage area Ca1 at the first position P1.

Here, the flow path area Ca of the radial flow path 61 refers to the cross-sectional area of the radial flow path 61 when the radial flow path 61 is cut along a plane perpendicular to its extension direction (i.e., the radial direction).
Further, the first position P1 and the second position P2 are assumed positions to represent the relative radial positional relationship in the radial flow passage 61, and do not indicate specific radial positions. For example, in the radial flow passage 61, when a certain radial position Pa is defined as the first position P1, any position radially inward from the radial position Pa can be the second position.

In the heat exchange core 10 according to some embodiments, the circumferential dimension Lc2 of the radial flow passage 61 at the second position P2 may be made smaller than the circumferential dimension Lc1 (see FIG. 4) of the radial flow passage 61 at the first position P1, so that the flow passage area Ca2 at the second position P2 is smaller than the flow passage area Ca1 at the first position P1. Also, the axial dimension La2 of the radial flow passage 61 at the second position P2 may be made smaller than the axial dimension La1 (see FIG. 6) of the radial flow passage 61 at the first position P1, so that the flow passage area Ca2 at the second position P2 is smaller than the flow passage area Ca1 at the first position P1.
In other words, by making at least one of the circumferential dimension Lc1 or the axial dimension La1 of the radial flow passage 61 at the first position P1 different from the circumferential dimension Lc2 or the axial dimension La2 of the radial flow passage 61 at the second position P2, the flow passage area Ca2 at the second position P2 may be made smaller than the flow passage area Ca1 at the first position P1.

In the radial flow passages 61, the fluid flow rate and pressure loss tend to increase toward the radially outer side of the region. Therefore, reducing the pressure loss in this region contributes to reducing the pressure loss throughout the heat exchange core 10.
According to the above configuration, the flow path area Ca2 at the second position P2 is smaller than the flow path area Ca1 at the first position P1. That is, according to the above configuration, the flow path area Ca1 at the first position P1 is larger than the flow path area Ca2 at the second position P2. This makes it possible to suppress pressure loss in the radially outer region of the radial flow paths 61, thereby suppressing pressure loss in the entire heat exchange core 10. Therefore, in the axial flow paths 3 connected to the radial flow paths 61 via the circumferential flow paths 66, the difference in flow rate depending on the radial position can be suppressed, and the heat exchange efficiency in the heat exchange core 10 can be improved.

As described above, the circumferential dimension Lc2 of each radial flow passage 61 at the second position P2 may be smaller than the circumferential dimension Lc1 at the first position P1.
This allows the flow path area Ca1 at the first position P1 to be larger than the flow path area Ca2 at the second position P2.
In order to make the flow path area Ca1 at the first position P1 larger than the flow path area Ca2 at the second position P2, as described above, there are two methods: making the circumferential dimension Lc1 at the first position P1 larger than the circumferential dimension Lc2 at the second position P2; and making the axial dimension La1 at the first position P1 larger than the axial dimension La2 at the second position P2.
In this case, if the flow path area Ca is changed by mainly changing the circumferential dimension Lc between the first position P1 and the second position P2, it is possible to reduce the axial dimension La of each radial flow path 61 over the entire radial direction, thereby reducing the axial dimension of the header portion 11.

As described above, the axial dimension La2 of each radial flow passage 61 at the second position P2 may be smaller than the axial dimension La1 at the first position P1.
This allows the flow path area Ca1 at the first position P1 to be larger than the flow path area Ca2 at the second position P2.
Furthermore, by changing the flow path area Ca mainly by changing the axial dimension La between the first position P1 and the second position P2, it is possible to suppress the circumferential dimension Lc of each radial flow path 61 over the entire radial direction. This makes it possible to suppress the proportion of the area occupied by the radial flow paths 61 and increase the proportion of the area occupied by the circumferential flow paths 66 in the cross section (second transverse cross section C2) of the header portion 11 when viewed from the axial direction D1.

In the header portion 11 according to some embodiments, the flow path area Ca may be configured to gradually decrease toward the inside in the radial direction.
As a result, the radial flow passage 61 is formed so that the flow passage area Ca gradually increases as it moves radially outward, thereby avoiding the formation of a sudden change in the flow passage cross-sectional area Ca and suppressing pressure loss in the radial flow passage 61.

(Regarding openings with radial flow paths)
1, in the heat exchange core 10 according to some embodiments, at least one opening 63 is formed by at least one radial flow passage 61 on the outer peripheral surface of the heat exchange core 10 in the header portion 11. In the heat exchange core 10 according to some embodiments, the total area ΣOa of the opening areas Oa of the openings 63 may be equal to or smaller than the total area ΣSc of the areas Sc of the multiple circumferential flow passages 66 when viewed from the axial direction D1.

In the heat exchange core 10 according to some embodiments, when the radial flow passages 61 are formed so that the total area ΣOa of the opening areas Oa of each opening 63 exceeds the total area ΣSc of the areas Sc of the multiple circumferential flow passages 66 as viewed from the axial direction D1, the pressure loss of the fluid flowing through the radial flow passages 61 and the circumferential flow passages 66 is affected more by the pressure loss in the circumferential flow passages 66. Therefore, even if the total area ΣOa of the opening areas Oa of each opening 63 is increased to exceed the total area ΣSc of the areas Sc of the multiple circumferential flow passages 66 as viewed from the axial direction D1, the effect of suppressing the pressure loss in the radially outer region of the radial flow passages 61 does not increase so much compared to the case where the total area ΣSc of the areas Sc of the multiple circumferential flow passages 66 as viewed from the axial direction D1 and the total area ΣOa of the opening areas Oa of each opening 63 are the same.
Conversely, by increasing the total area ΣOa of the opening areas Oa of the openings 63 so as to exceed the total area ΣSc of the areas Sc of the multiple circumferential flow passages 66 as viewed from the axial direction D1, the circumferential dimension Lc and the axial dimension La of the radial flow passages 61 become large, which may cause the following effects.
In other words, as the circumferential dimension Lc of the radial flow passage 61 increases, the proportion of the area occupied by the radial flow passage 61 in the cross section (second transverse cross section C2) of the header section 11 when viewed from the axial direction D1 may increase, and the proportion of the area occupied by the circumferential flow passage 66 may decrease.
Furthermore, an increase in the axial dimension La of the radial flow passage 61 may result in an increase in the axial dimension of the header portion 11 .
According to some embodiments of the heat exchange core 10, pressure loss in the radially outer region of the radial flow passage 61 can be effectively suppressed while suppressing the impact on the area occupied by the circumferential flow passage 66 in the cross section (second transverse cross section C2) of the header section 11 when viewed from the axial direction D1 and the impact on the axial dimension of the header section 11.

(About the shape of the opening)
FIG. 8 is a diagram that illustrates a part of the side surface of the heat exchange core 10 in the vicinity of the header portion 11 according to some embodiments, and illustrates an example of the shape of the opening 63.
FIG. 9 is a diagram that illustrates a part of the side surface of the heat exchange core 10 in the vicinity of the header portion 11 according to some embodiments, and illustrates another example of the shape of the opening 63.

In the heat exchange core 10 according to some embodiments, the flow rate of the fluid is relatively large near the opening 63 of the radial flow passage 61, and pressure loss tends to be relatively large, so it is desirable to increase the opening area on the opening 63 side as much as possible. However, widening the radial flow passage 61 in the circumferential direction D2 may affect the flow of fluid in the axial flow passage 3, so it is desirable to suppress the expansion of the flow passage width in the circumferential direction D2. Therefore, in the radial flow passage 61, it is preferable to widen the flow passage width in the axial direction D1.
Therefore, in the heat exchange core 10 according to some embodiments, the shape of the opening 63 is set as follows.
That is, in the heat exchange core 10 according to some embodiments, as shown in Figures 8 and 9, the opening dimension AL1 along the axial direction D1 of each opening 63 is at least 1 time the opening dimension AL2 along the circumferential direction D2 of each opening 63 (1.0 x AL2 ≦ AL1).
This makes it possible to reduce the opening dimension AL2 in the circumferential direction D2 of each opening 63. Therefore, since the dimension in the circumferential direction D2 of the radial flow passages 61 can be reduced, it is possible to reduce the proportion of the area occupied by the radial flow passages 61 in the cross section (second transverse cross section C2) of the header portion 11 when viewed from the axial direction D1, and to increase the proportion of the area occupied by the circumferential flow passages 66.

For example, in the heat exchange core 10 shown in Fig. 8, the opening 63 has a rectangular shape when viewed from the radial outside. Also, in the heat exchange core 10 shown in Fig. 9, the end 64 along the axial direction of the opening 63 is formed so that the dimension in the circumferential direction D2 decreases as it moves toward the outside of the radial flow passage 61 along the axial direction D1 when viewed from the radial outside. That is, in the heat exchange core 10 according to some embodiments, the radial flow passage 61 may be formed so that the dimension AL2 in the circumferential direction D2 decreases as it moves toward the outside of the radial flow passage 61 along the axial direction D1 at at least one end 64 of the two ends 64 along the axial direction D1.
As a result, for example, as described below, when the heat exchange core 10 is manufactured by additive manufacturing, when the axial direction D1 is the stacking direction, the end portion 64 of the radial flow passage 61 along the axial direction D1 is unlikely to become an overhang region. This makes it possible to simplify or eliminate the process of manufacturing supports for manufacturing the overhang region and the process of removing the manufactured supports.

(Change in flow area of radial flow passage with respect to change in radial position)
FIG. 10 is a schematic diagram for explaining a change in the flow passage area Ca of the radial flow passage 61 with respect to a change in radial position, and is a diagram of the heat exchange core 10 as viewed along the axial direction D1.
For ease of explanation, in Fig. 10, a schematic shape of the first radial flow passage 61A which is the radial flow passage 61 in the first header portion 11A and a schematic shape of the second radial flow passage 61B which is the radial flow passage 61 in the second header portion 11B are shown overlapping along the axial direction D1. Note that, for ease of illustration, in Fig. 10, the schematic shape of the first radial flow passage 61A is shown by a dashed line, and the schematic shape of the second radial flow passage 61B is shown by a two-dot chain line.
Fig. 11 is a schematic diagram for explaining the change in flow path area Ca of the radial flow path 61 with respect to the change in radial position, and is a diagram viewed along the radial direction of the heat exchange core 10. In Fig. 11, the schematic shape of the first radial flow path 61A and the schematic shape of the second radial flow path 61B are indicated by two-dot chain lines.

In the heat exchange core 10 according to some embodiments, as described above, the flow rate of the fluid is relatively large near the openings 63 of the radial channels 61, and therefore the dynamic pressure is relatively large. On the other hand, the flow rate is smaller near the cylindrical center of the radial channels 61 than near the openings 63, and therefore the dynamic pressure is much smaller than near the openings 63.
If the difference in dynamic pressure due to differences in radial position becomes large enough to exceed a certain level, the deviation between the axial flow passages 3 near the opening 63 (i.e., the radially outer side) and the axial flow passages 3 near the center will become large, which may result in a decrease in performance of the heat exchange core 10.
In addition, since the deviation tends to increase as the dynamic pressure increases, the deviation is likely to be large in fluids with high density.
Therefore, it is preferable to increase the area increase rate Rca, which will be described later, for a fluid with a higher density, thereby decreasing the flow velocity near the opening 63 more.

Generally, the density of a fluid varies with temperature, and generally, the change in density with temperature is greater for gases than for liquids.
Therefore, when the temperature of the fluid changes as it flows through the heat exchange core 10, it may be advantageous to make the area increase rate Rca, described later, different between the radial flow passages 61 in the header section 11 located upstream of the fluid flow and the radial flow passages 61 in the header section 11 located downstream of the fluid flow.

Therefore, in the heat exchange core 10 according to some embodiments, the shape of the radial flow passages 61 is set as follows.
That is, in the heat exchange core 10 according to some embodiments, the area increase rate Rca of the flow path area Ca, which increases from the radial inside to the radial outside in at least one radial flow path 61, differs between at least one radial flow path 61 (first radial flow path 61A) in the first header portion 11A and at least one radial flow path 61 (second radial flow path 61B) in the second header portion 11B.
Here, the area increase rate Rca is the difference (Ca1-Ca2) between the flow path area Ca1 at the first position P1 and the flow path area Ca2 at the second position P2 divided by the difference in radial position between the first position P1 and the second position P2.

In order to make the area increase rate Rca different between the first radial flow passage 61A and the second radial flow passage 61B, for example, as shown in Fig. 10, the dimensional increase rate Rlc of the circumferential dimension Lc, which increases from the inside to the outside in the radial direction, may be made different between the first radial flow passage 61A and the second radial flow passage 61B. Also, in order to make the area increase rate Rca different between the first radial flow passage 61A and the second radial flow passage 61B, for example, as shown in Fig. 11, the dimensional increase rate Rla of the axial dimension La, which increases from the inside to the outside in the radial direction, may be made different between the first radial flow passage 61A and the second radial flow passage 61B.
In other words, the area increase rate Rca may be made different between the first radial flow passage 61A and the second radial flow passage 61B by making at least one of the dimensional increase rate Rlc for the circumferential dimension Lc or the dimensional increase rate Rla for the axial dimension La different between the first radial flow passage 61A and the second radial flow passage 61B.

In the heat exchange core 10 according to some embodiments, it is desirable to keep the difference in static pressure between the first header portion 11A and the second header portion 11B at any radial position in the radial flow path 61 constant regardless of the radial position.
When the fluid circulating through the heat exchange core 10 is, for example, a gas, the rate of change in density due to a change in temperature tends to be larger than that when the fluid is a liquid, as described above. Therefore, if the area increase rate Rca is the same for the first radial flow passage 61A and the second radial flow passage 61B, the static pressure difference described above may vary significantly depending on the radial position.
According to the above configuration, the area increase rate Rca differs between the first radial flow passage 61A and the second radial flow passage 61B, so that it is possible to suppress the above-mentioned difference in static pressure from varying depending on the radial position.

(Regarding the manufacturing method of the heat exchange core)
An example of a method for manufacturing the heat exchange core 10 according to some of the above-described embodiments will now be described.
FIG. 12 is a flow chart illustrating steps in a method for manufacturing the heat exchange core 10 according to some of the embodiments described above.
The manufacturing method of the heat exchange core 10 according to some of the above-mentioned embodiments includes a core body forming process S1 in which a core body 13 including a plurality of axial flow paths 3 extending along the axial direction D1 is formed by additive manufacturing, and a header portion forming process S3 in which a header portion 11 is formed by additive manufacturing, the header portion 11 being adjacent to at least one end of the core body 13 in the axial direction D1 and having a header flow path 6 communicating with the plurality of axial flow paths 3.

The header portion forming process S3 forms the header flow passage 6 to include at least one radial flow passage 61 extending along the radial direction, and a plurality of circumferential flow passages 66 branching off from one of the radial flow passages 61 and each communicating with one or more axial flow passages 3.
In addition, the header portion forming process S3 may form each radial flow path 61 so that the flow path area Ca2 at the second position P2, which is radially inward from the first position P1, is smaller than the flow path area Ca1 at the first position P1.
In addition, the header portion forming process S3 may form the header portion 11 so that at least one opening 63 is formed by at least one radial flow path 61 on the outer peripheral surface of the heat exchange core 10 in the header portion 11, and the header portion 11 may be formed so that the opening dimension AL1 along the axial direction D1 of each opening 63 is at least one time the opening dimension AL2 along the circumferential direction of each opening 63.
This makes it possible to integrally form the heat exchange core 10 by additive manufacturing, eliminating the need to assemble components or seal between components with gaskets, thus significantly reducing the amount of maintenance work required.

The present disclosure is not limited to the above-described embodiments, but also includes variations of the above-described embodiments and appropriate combinations of these embodiments.

The contents described in each of the above embodiments can be understood, for example, as follows.
(1) A heat exchange core 10 according to at least one embodiment of the present disclosure includes a core body portion 13 and a header portion 11. The core body portion 13 includes a plurality of axial flow passages 3 extending along the axial direction D1. The header portion 11 has a header flow passage 6 adjacent to at least one end of the core body portion 13 in the axial direction D1 and communicating with the plurality of axial flow passages 3.
The header flow passage 6 includes at least one radial flow passage 61 extending along the radial direction. The header flow passage 6 includes a plurality of circumferential flow passages 66 branching off from each of the radial flow passages 61 and communicating with one or more of the axial flow passages 3, respectively.
In each of the radial flow passages 61, a flow passage area Ca2 at a second position P2 radially inward from the first position P1 is smaller than a flow passage area Ca1 at the first position P1.

In the radial flow passages 61, the fluid flow rate and pressure loss tend to increase toward the radially outer side of the region. Therefore, reducing the pressure loss in this region contributes to reducing the pressure loss throughout the heat exchange core 10.
According to the above configuration (1), the flow path area Ca2 at the second position P2 radially inward from the first position P1 is smaller than the flow path area Ca1 at the first position P1. That is, according to the above configuration (1), the flow path area Ca1 at the first position P1 radially outward from the second position P2 is larger than the flow path area Ca2 at the second position P2. This makes it possible to suppress pressure loss in the radially outer region of the radial flow path 61, thereby suppressing pressure loss in the entire heat exchange core 10. Therefore, in the axial flow path 3 connected to the radial flow path 61 via the circumferential flow path 66, the difference in flow rate depending on the radial position can be suppressed, and the heat exchange efficiency in the heat exchange core 10 can be improved.

(2) In some embodiments, in the configuration of (1) above, the circumferential dimension Lc2 of each radial flow passage 61 at the second position P2 is smaller than the circumferential dimension Lc1 at the first position P1.

According to the above configuration (2), by making the circumferential dimension Lc2 at the second position P2 smaller than the circumferential dimension Lc1 at the first position P1 in each radial flow passage 61, that is, by making the circumferential dimension LC1 at the first position P1 larger than the circumferential dimension LC2 at the second position P2, the flow passage area Ca1 at the first position P1 can be made larger than the flow passage area Ca2 at the second position P2.
If the flow passage area Ca is changed by mainly changing the circumferential dimension Lc between the first position P1 and the second position P2, it is possible to reduce the dimension La in the axial direction D1 of each radial flow passage 61 over the entire radial direction. This makes it possible to reduce the axial dimension of the header portion 11.

(3) In some embodiments, in the configuration of (1) or (2) above, the axial dimension La2 of each radial flow passage 61 at the second position P2 is smaller than the axial dimension La1 at the first position P1.

According to the above configuration (3), by making the axial dimension La2 at the second position P2 smaller than the axial dimension La1 at the first position P1 in each radial flow passage 61, i.e., by making the axial dimension La1 at the first position P1 larger than the axial dimension La2 at the second position P2, the flow passage area Ca1 at the first position P1 can be made larger than the flow passage area Ca2 at the second position P2.
If the flow path area Ca is changed by mainly changing the axial dimension La between the first position P1 and the second position P2, it is possible to suppress the circumferential dimension Lc of each radial flow path 61 over the entire radial direction. This makes it possible to suppress the proportion of the area occupied by the radial flow paths 61 and increase the proportion of the area occupied by the circumferential flow paths 66 in the cross section (second transverse cross section C2) of the header portion 11 when viewed from the axial direction D1.

(4) In some embodiments, in any of the configurations (1) to (3) above, the flow passage area Ca gradually decreases toward the radially inward direction.

According to the configuration (4) above, the radial flow passage 61 is formed so that the flow passage area Ca gradually increases as it moves radially outward, so that it is possible to avoid the formation of a sudden change in the flow passage cross-sectional area Ca, and it is possible to suppress pressure loss in the radial flow passage 61.

(5) In some embodiments, in any of the configurations (1) to (4) above, at least one opening 63 is formed on the outer peripheral surface of the heat exchange core 10 in the header portion 11 by at least one radial flow path 61. The total area ΣOa of the opening areas Oa of the openings 63 is less than or equal to the total area ΣSc of the areas Sc of the multiple circumferential flow paths 66 when viewed from the axial direction D1.

The above configuration (5) can effectively suppress pressure loss in the radially outer region of the radial flow passage 61 while suppressing the impact on the area occupied by the circumferential flow passage 66 in the cross section (second transverse cross section C2) of the header section 11 when viewed from the axial direction D1 and the impact on the axial dimension of the header section 11.

(6) In some embodiments, in any of the configurations (1) to (5) above, at least one opening 63 is formed on the outer peripheral surface of the heat exchange core 10 in the header portion 11 by at least one radial flow path 61. The opening dimension AL1 of each opening 63 along the axial direction D1 is equal to or greater than one time the opening dimension AL2 of each opening 63 along the circumferential direction D2.

According to the above configuration (6), the opening dimension AL2 in the circumferential direction D2 of each opening 63 can be suppressed. This allows the dimension in the circumferential direction D2 of the radial flow passage 61 to be suppressed, so that the proportion of the area occupied by the radial flow passage 61 in the cross section (second transverse cross section C2) of the header portion 11 when viewed from the axial direction D1 can be suppressed and the proportion of the area occupied by the circumferential flow passage 66 can be increased.

(7) In some embodiments, in any of the configurations (1) to (6) above, at least one radial flow passage 61 is formed such that the dimension in the circumferential direction D2 decreases toward the outside of the radial flow passage 61 along the axial direction D1 at at least one of the two ends 64 along the axial direction D1.

According to the configuration of (7) above, for example, when the heat exchange core 10 is manufactured by additive manufacturing, when the axial direction D1 is the stacking direction, the end 64 of the radial flow passage 61 along the axial direction D1 is unlikely to become an overhang region. This simplifies or eliminates the process of manufacturing supports for manufacturing the overhang region and the process of removing the manufactured supports.

(8) In some embodiments, in any of the configurations (1) to (7) above, the header portion 11 includes a first header portion 11A adjacent to one end of the core body portion 13 in the axial direction D1, and a second header portion 11B adjacent to the other end of the core body portion 13 in the axial direction D1. The area increase rate Rca of the flow passage area Ca that increases from the radial inside to the radial outside in at least one radial flow passage 61 differs between the at least one radial flow passage 61 in the first header portion 11A and the at least one radial flow passage 61 in the second header portion 11B.

According to the configuration (8) above, the area increase rate Rca differs between the radial flow passages 61 in the first header section 11A and the radial flow passages 61 in the second header section 11B, so that the static pressure difference described above can be prevented from varying depending on the radial position.

(9) A heat exchange core 10 according to at least one embodiment of the present disclosure includes a core body portion 13 and a header portion 11. The core body portion 13 includes a plurality of axial flow passages 3 extending along the axial direction D1. The header portion 11 has a header flow passage 6 adjacent to at least one end portion of the core body portion 13 in the axial direction D1 and communicating with the plurality of axial flow passages 3.
The header flow passage 6 includes at least one radial flow passage 61 extending along the radial direction. The header flow passage 6 includes a plurality of circumferential flow passages 66 branching off from each of the radial flow passages 61 and communicating with one or more of the axial flow passages 3, respectively.
At least one opening 63 is formed in the outer peripheral surface of the heat exchange core 10 in the header portion 11 by at least one radial flow passage 61 .
An opening dimension AL1 of each opening 63 along the axial direction D1 is equal to or greater than one time an opening dimension AL2 of each opening 63 along the circumferential direction D2.

According to the above configuration (9), the opening dimension AL2 in the circumferential direction D2 of each opening 63 can be suppressed. This allows the dimension in the circumferential direction D2 of the radial flow passage 61 to be suppressed, so that the proportion of the area occupied by the radial flow passage 61 in the cross section (second transverse cross section C2) of the header portion 11 when viewed from the axial direction D1 can be suppressed and the proportion of the area occupied by the circumferential flow passage 66 can be increased.

(10) In some embodiments, in the configuration of (9) above, the total area ΣOa of the opening areas Oa of each opening 63 is less than or equal to the total area ΣSc of the areas Sc of the multiple circumferential flow paths 66 when viewed from the axial direction D1.

The above configuration (10) can effectively suppress pressure loss in the radially outer region of the radial flow passage 61 while suppressing the impact on the area occupied by the circumferential flow passage 66 in the cross section (second transverse cross section C2) of the header section 11 when viewed from the axial direction D1 and the impact on the axial dimension of the header section 11.

(11) In some embodiments, in the configuration of (9) or (10) above, at least one radial flow passage 61 is formed such that the dimension in the circumferential direction D2 decreases toward the outside of the radial flow passage 61 along the axial direction D1 at at least one of the two ends 64 along the axial direction D1.

According to the above configuration (11), for example, when the heat exchange core 10 is manufactured by additive manufacturing, when the axial direction D1 is the stacking direction, the end 64 of the radial flow passage 61 along the axial direction D1 is unlikely to become an overhang region. This simplifies or eliminates the process of manufacturing supports for manufacturing the overhang region and the process of removing the manufactured supports.

(12) In some embodiments, in any of the configurations (1) to (11) above, the multiple axial flow paths 3 are arranged in a circular ring shape when viewed from the axial direction D1.

The above configuration (12) allows the stress acting due to the fluid pressure, etc., to be uniformly distributed throughout the heat exchange core 10.

(13) In some embodiments, in any of the configurations (1) to (12) above, the multiple axial flow paths 3 are each divided into multiple sections S in the circumferential direction D2.

According to the above configuration (13), the heat transfer efficiency can be improved by the presence of a wall that divides the axial flow path 3. The wall can improve the rigidity and strength of the heat exchange core 10, particularly in the radial direction.

(14) In some embodiments, in the configuration of (13) above, the flow passage diameters of the multiple axial flow passages 3 are uniform among the multiple sections S.

According to the above configuration (14), the flow conditions such as friction loss are uniform in all sections, which makes it possible to uniformize the heat transfer coefficient in all sections, and the stress is uniformly distributed throughout the entire in-plane direction of the cross section of the heat exchange core 10, which makes it possible to uniformize the stress.

(15) The heat exchanger 1 according to at least one embodiment of the present disclosure comprises a heat exchange core 10 having any of the configurations (1) to (14) above, and a casing 20 that houses the heat exchange core 10.

The above configuration (15) allows the heat exchanger 1 to be made relatively small and improves heat exchange efficiency.

(16) A manufacturing method of a heat exchange core 10 according to at least one embodiment of the present disclosure includes a core body forming process S1 for forming a core body 13 including a plurality of axial flow paths 3 extending along the axial direction D1 by additive manufacturing, and a header portion forming process S3 for forming a header portion 11 adjacent to at least one end of the core body 13 in the axial direction D1 and having a header flow path 6 communicating with the plurality of axial flow paths 3 by additive manufacturing.
The header portion forming process S3 forms the header flow passage 6 so as to include at least one radial flow passage 61 extending along the radial direction, and a plurality of circumferential flow passages 66 branching from any of the radial flow passages 61 and communicating with one or more axial flow passages 3. The header portion forming process S3 forms each of the radial flow passages 61 so that a flow passage area Ca2 at a second position P2 radially inward from the first position P1 is smaller than a flow passage area Ca1 at the first position P1.

According to the method (16) above, it is possible to form the heat exchange core 10 as a single unit by additive manufacturing, so there is no need to assemble the components or seal between the components with gaskets. This significantly reduces the amount of maintenance work required.

(17) A manufacturing method of a heat exchange core 10 according to at least one embodiment of the present disclosure includes a core body forming process S1 for forming a core body 13 including a plurality of axial flow paths 3 extending along the axial direction D1 by additive manufacturing, and a header portion forming process S3 for forming a header portion 11 adjacent to at least one end of the core body 13 in the axial direction D1 and having a header flow path 6 communicating with the plurality of axial flow paths 3 by additive manufacturing.
The header portion forming process S3 forms the header flow passage 6 so as to include at least one radial flow passage 61 extending along the radial direction and a plurality of circumferential flow passages 66 branching off from any of the radial flow passages 61 and communicating with one or more axial flow passages 3. The header portion forming process S3 forms the header portion 11 so that at least one opening 63 is formed by at least one radial flow passage 61 on the outer circumferential surface of the heat exchange core 10 in the header portion 11, and forms the header portion 11 so that an opening dimension AL1 in the axial direction D1 of each opening 63 is equal to or greater than one time an opening dimension AL2 in the circumferential direction D2 of each opening 63.

According to the method (17) above, it is possible to form the heat exchange core 10 as a single unit by additive manufacturing, so there is no need to assemble the components or seal between the components with gaskets. This significantly reduces the amount of work required for maintenance.

Reference Signs List 1 Heat exchanger 3 Axial flow passage 6 Header flow passage 10 Heat exchange core 11 Header section 11A First header section 11B Second header section 13 Core body section 61 Radial flow passage 63 Opening 66 Circumferential flow passage

Claims (17)

a core body including a plurality of axial flow passages extending along an axial direction;
a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages,
The header flow path is
At least one radial flow passage extending along a radial direction;
A plurality of circumferential flow paths branching from each of the radial flow paths and communicating with one or more of the axial flow paths, respectively;
Including,
A heat exchange core, wherein each of the radial flow passages has a flow passage area at a second position radially inward from the first position that is smaller than the flow passage area at the first position. The heat exchange core of claim 1 , wherein each of the radial flow passages has a smaller circumferential dimension at the second location than at the first location. The heat exchange core according to claim 1 or 2, wherein the axial dimension of each of the radial flow passages at the second position is smaller than the axial dimension at the first position. The heat exchange core according to claim 1 , wherein the flow passage area gradually decreases toward the inside in the radial direction. At least one opening is formed in the outer peripheral surface of the heat exchange core in the header portion by the at least one radial flow passage,
5 . The heat exchange core according to claim 1 , wherein a total area of opening areas of the openings is equal to or less than a total area of the plurality of circumferential flow paths when viewed in the axial direction. At least one opening is formed in the outer peripheral surface of the heat exchange core in the header portion by the at least one radial flow passage,
The heat exchange core according to claim 1 , wherein an opening dimension of each of the openings along the axial direction is at least one time a opening dimension of each of the openings along the circumferential direction. A heat exchange core as described in any one of claims 1 to 6, wherein at least one of the two ends along the axial direction is formed so that its circumferential dimension decreases toward the outside of the radial flow path along the axial direction at at least one of the two ends along the axial direction. the header portion includes a first header portion adjacent to the one end of the core body portion in the axial direction, and a second header portion adjacent to the other end of the core body portion in the axial direction,
A heat exchange core as described in any one of claims 1 to 7, wherein the area increase rate of the flow path area that increases from the inside to the outside in the radial direction in the at least one radial flow path is different between the at least one radial flow path in the first header section and the at least one radial flow path in the second header section. a core body including a plurality of axial flow passages extending along an axial direction;
a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages,
The header flow path is
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from each of the radial flow paths and each communicating with one or more of the axial flow paths;
Including,
At least one opening is formed in the outer circumferential surface of the heat exchange core in the header portion by the at least one radial flow passage,
A heat exchange core, wherein an opening dimension of each of the openings along the axial direction is greater than or equal to one time a opening dimension of each of the openings along the circumferential direction. The heat exchange core according to claim 9 , wherein a total area of the openings is equal to or smaller than a total area of the plurality of circumferential flow paths when viewed in the axial direction. A heat exchange core as described in claim 9 or 10, wherein the at least one radial flow passage is formed so that its circumferential dimension decreases toward the outside of the radial flow passage along the axial direction at at least one of the two ends along the axial direction. The heat exchange core according to claim 1 , wherein the plurality of axial flow passages are arranged in an annular shape when viewed from the axial direction. The heat exchange core according to claim 1 , wherein each of the axial flow passages is divided into a plurality of sections in the circumferential direction. The plurality of axial flow passages are configured such that the flow passage diameters of the plurality of compartments are uniform.
The heat exchange core of claim 13. A heat exchange core according to any one of claims 1 to 14;
a casing that houses the heat exchange core;
A heat exchanger comprising: 1. A method for manufacturing a heat exchange core, comprising the steps of:
forming a core body portion including a plurality of axial flow passages extending along an axial direction by additive manufacturing;
and forming a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages by additive manufacturing.
The step of forming the header portion includes:
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from any one of the radial flow paths and each communicating with one or more of the axial flow paths;
forming the header flow passage so as to include
A manufacturing method for a heat exchange core in which the process of forming the header portion forms each of the radial flow paths so that the flow path area at a second position radially inward from the first position is smaller than the flow path area at the first position. 1. A method for manufacturing a heat exchange core, comprising the steps of:
forming a core body portion including a plurality of axial flow paths extending along an axial direction and including a side wall disposed on an outermost periphery by additive manufacturing;
and forming a header portion adjacent to at least one end of the core body portion in the axial direction and having a header flow passage communicating with the plurality of axial flow passages by additive manufacturing.
The step of forming the header portion includes:
At least one radial flow passage extending along a radial direction;
a plurality of circumferential flow paths branching from any one of the radial flow paths and each communicating with one or more of the axial flow paths;
forming the header flow passage so as to include
The step of forming the header portion includes:
The header portion is formed such that at least one opening is formed in the side wall of the heat exchange core in the header portion by the at least one radial flow path;
A manufacturing method for a heat exchange core, in which the header portion is formed so that an opening dimension of each of the openings along the axial direction is at least one time the opening dimension of each of the openings along the circumferential direction.

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