Cooling wall part structure, high-temperature component provided with the same, and method for manufacturing cooling wall part structure

Abstract

To provide a cooling wall part structure that has high cooling efficiency, and that is easy to process and excellent in durability.SOLUTION: A cooling wall part structure is provided with: an inner surface that faces a high-temperature space in which combustion gas flows; and a cooling flow path 15 that is inclined at a first angle with respect to the inner surface, guides cooling air from an opening formed in the inner surface in a direction in which the combustion gas flows, and cools the inner surface on the downstream side of the opening. The cooling flow path 15 is provided with: a main flow path 17; and branch flow paths 18, 19 that are branched from a branch position D1 in the middle of the main flow path 17 and are provided on both sides of the main flow path 17 when the inner surface is seen in a plan view. At the branch position D1, there is formed a branch position wall surface 22 that is formed from the inner surface to the main flow path 17 and has a second angle greater than the first angle.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a cooling wall structure suitable for use in, for example, a combustor or a turbine blade, a high-temperature component including the cooling wall structure, and a method for manufacturing the cooling wall structure. [Background technology]

[0002] 2. Description of the Related Art For high-temperature components such as the combustor and turbine blades of an aircraft engine, various proposals have been made to perform film cooling by flowing a portion of compressed air over the surfaces of the components in order to improve their durability.

[0003] Patent Document 1 listed below discloses a cooling flow path in which a cylindrical hole, which is a simple cylindrical cooling hole, is curved so that it has a crescent-shaped cross section, and three branches are added downstream. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 8,850,828 Summary of the Invention [Problem to be solved by the invention]

[0005] The shape of the cooling flow passage disclosed in Patent Document 1 is expected to have high cooling efficiency, but the cross-sectional shape must be curved into a crescent shape and a branch flow passage must be formed downstream. This makes the flow passage shape complex and difficult to manufacture, especially by laser processing. For example, when applied to the combustor or turbine blade of an aircraft engine, the size is smaller than that of an industrial gas turbine, making processing even more difficult.

[0006] As shown in FIG. 4 of Patent Document 1, an overhanging part (position indicated by reference numeral 120 in the figure) with a thin wall is formed upstream of the opening of the cooling flow path. The overhanging part is easily damaged because of its thin thickness and small heat capacity. In addition, when a topcoat layer is formed on the surface of the wall to improve heat resistance, delamination is likely to occur due to differences in the linear expansion coefficients of the topcoat layer, the base material, and the bond layer formed between them.

[0007] The present disclosure has been made in consideration of the above circumstances, and aims to provide a cooling wall structure that has high cooling efficiency, is easy to process, and has excellent durability, as well as a high-temperature component including the same, and a method for manufacturing the cooling wall structure. [Means for solving the problem]

[0008] A cooling wall structure according to one embodiment of the present disclosure comprises a first wall surface facing a high-temperature space through which a high-temperature fluid flows, and a cooling flow path inclined at a first angle relative to the first wall surface and guiding a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows to cool the first wall surface downstream of the opening, wherein the cooling flow path comprises a first flow path and a branch flow path branched from a branching position midway through the first flow path and provided on each side of the first flow path when the first wall surface is viewed in a plane, and at the branching position, a branching position wall surface is formed extending from the first wall surface to the first flow path and having a second angle greater than the first angle.

[0009] A high-temperature component according to one aspect of the present disclosure includes the above-described cooling wall structure.

[0010] A manufacturing method for a cooling wall structure according to one embodiment of the present disclosure includes a first wall surface facing a high-temperature space through which a high-temperature fluid flows, and a cooling flow path inclined at a first angle with respect to the first wall surface and guiding a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows to cool the first wall surface downstream of the opening, wherein the cooling flow path includes a first flow path and a branch flow path branched from a branching position midway through the first flow path and provided on each side of the first flow path when the first wall surface is viewed in a plane, and at the branching position, a branching position wall surface is formed that is formed from the first wall surface to the first flow path and has a second angle greater than the first angle, the manufacturing method for a cooling wall structure includes a first step of forming each of the branching flow paths together with the branching position wall surface by laser processing, and a second step of forming the first flow path by laser processing. Effect of the Invention

[0011] It has high cooling efficiency, is easy to process, and improves durability. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a longitudinal cross-sectional view of a combustor according to one embodiment of the present disclosure. [Diagram 2] 2 is an enlarged vertical cross-sectional view of the cooling wall structure of FIG. 1. [Diagram 3] FIG. 3 is a perspective view showing the cooling passage of FIG. 2. [Figure 4] FIG. 4 is an enlarged perspective view of the outlet opening of FIG. 3. [Diagram 5] 10 is a vertical cross-sectional view of a wall portion showing a state in which a branch position wall surface is formed up to the boundary position between the top coat layer and the bond layer. FIG. [Figure 6] FIG. 3 is a vertical cross-sectional view corresponding to FIG. 2 and showing an overhang portion. [Figure 7] 10 is a vertical cross-sectional view of a wall portion showing a state in which a branch position wall surface is formed up to the boundary position between the bond layer and the base material. FIG. [Figure 8] FIG. 11 is a vertical cross-sectional view of a wall portion showing a state in which a branch position wall surface is formed up to the inside of the base material. [Figure 9] FIG. 11 is a perspective view showing a cooling passage of a cooling wall structure according to Modification 1. [Figure 10] FIG. 10 is a vertical sectional view showing the cooling wall structure of FIG. [Figure 11] FIG. 11 is a perspective view showing a cooling flow passage of a cooling wall structure according to Modification 2. [Figure 12] FIG. 12 is a perspective view showing only the main flow path in FIG. [Figure 13] FIG. 11 is a plan view showing a cooling passage of a cooling wall structure according to Modification 3. [Figure 14] FIG. 11 is a vertical cross-sectional view showing a cooling wall structure according to a fourth modified example. [Figure 15] FIG. 15 is a vertical sectional view showing a modified example of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. FIG. 1 shows a combustor (high-temperature component) 1 of an aircraft engine. As shown in FIG. 1, the combustor 1 has a combustor liner 5 provided in a main casing 3. Fuel F and compressed air A are supplied into the combustor liner 5, and a flame FL is formed. A cooling flow passage is formed in the wall of the combustor liner 5, and a part of the compressed air A is supplied as cooling air A1 from the outer periphery to the inner periphery of the combustor liner 5. The cooling air A1 flows in a film shape on the inner surface of the wall of the combustor liner 5, thereby performing film cooling. In this manner, the combustor liner 5 has a cooling wall structure 10 that protects the wall from high-temperature combustion gas G.

[0014] Fig. 2 shows a cooling wall structure 10. The cooling wall structure 10 in Fig. 2 is a partially enlarged view of the wall 9 of the combustor liner 5 in Fig. 1. In the figure, the direction x is the longitudinal direction of the combustor liner 5 (the mainstream direction of the combustion gas G), and the direction y is the thickness direction of the wall 9.

[0015] The cooling wall structure 10 has a cooling passage 15 formed so as to penetrate a wall 9 of a predetermined thickness. The wall 9 has an inner surface (first wall surface) 11 facing a high-temperature space S through which the combustion gas G flows, and an outer surface 12 facing the inner surface 11 and located upstream of the flow of cooling air A1 (see FIG. 1).

[0016] The cooling flow passage 15 is formed linearly between the inner surface 11 and the outer surface 12 with the first axis C1 as the central axis. The cooling flow passage 15 has an inlet opening 15a that opens to the outer surface 12 and an outlet opening 15b that opens to the inner surface 11. The cooling air A1 that flows in from the inlet opening 15a flows out from the outlet opening 15b into the high-temperature space S and flows along the inner surface 11 downstream of the outlet opening 15b, thereby performing film cooling. The cooling flow passage 15 is inclined at a first angle α1 formed by the first axis C1 with respect to the inner surface 11. The first angle α1 is, for example, 15° or more and 45° or less.

[0017] 3 shows a three-dimensional view of the shape of the cooling flow passage 15. The cooling flow passage 15 is composed of a main flow passage 17, a first branch flow passage 18, and a second branch flow passage 19. When the main flow passage 17 is viewed from above (when viewed from the inner surface 11), the first branch flow passage 18 is located on the left side of the flow direction of the cooling air A1 flowing through the main flow passage 17, and the second branch flow passage 19 is located on the right side of the flow direction of the cooling air A1 flowing through the main flow passage 17, when the main flow passage 17 is viewed from above. The first branch flow passage 18 and the second branch flow passage 19 are preferably provided symmetrically with respect to the main flow passage 17.

[0018] The main flow passage 17 has a circular cross section (flow passage cross section), has an inlet opening 15a on the outer surface 12, and has a main flow passage outlet opening 15b1 on the inner surface 11.

[0019] The first branch flow passage 18 branches leftward from a branch position D1 including a branch point P1. The branch point P1 is provided at a position corresponding to the midpoint of the first axis C1 of the main flow passage 17. The first branch flow passage 18 is formed along the second axis C2 direction, with the upper surface of the first branch flow passage 18 opening as a first branch opening 15b2 on the inner surface 11. The branch point P1 is the intersection of the first axis C1 and the second axis C2 passing through the bottom 18a. The first branch angle α3 formed by the second axis C2 and the first axis C1 of the main flow passage 17 is set to be 15° or more and 90° or less. This first branch angle α3 represents the angle when the first axis C1 and the second axis C2 are viewed from the direction V1 (perpendicular to the first axis C1) in the vertical cross section of FIG. 2.

[0020] 2, the first branch flow passage 18 is a bottomed groove portion that is dug to a certain depth in the thickness direction from the inner surface 11 toward the outer surface 12. That is, the first branch flow passage 18 has a so-called crater shape. A bottom 18a of the first branch flow passage 18 is a flat surface that extends approximately parallel to the inner surface 11, for example.

[0021] The second branch flow passage 19 branches off to the right from a branch position D1 including a branch point P1. The second branch flow passage 19 is formed along the third axis C3 direction, with the upper surface of the inner surface 11 opening as a second branch opening 15b3. The branch point P1 is the intersection of the first axis C1 and the third axis C3 passing through the bottom 19a. The second branch angle α4 formed by the third axis C3 and the first axis C1 of the main flow passage 17 is set to be 15° or more and 90° or less. This second branch angle α4 represents the angle when the first axis C1 and the third axis C3 are viewed from the direction V1 (perpendicular to the first axis C1) in the vertical cross section of FIG. 2. Preferably, the second branch angle α4 is equal to the first branch angle α3 (α3=α4).

[0022] 2, the second branch flow passage 19 is a bottomed groove portion that is dug to a certain depth in the thickness direction from the inner surface 11 toward the outer surface 12. That is, the second branch flow passage 19 has a so-called crater shape similar to the first branch flow passage 18. A bottom 19a of the second branch flow passage 19 is a flat surface that extends approximately parallel to the inner surface 11, for example.

[0023] A branch position wall surface 22 is formed on the upstream side of the branch point P1 on the first axis C1. The branch position wall surface 22 is formed from the inner surface 11 to the main flow path 17, and constitutes a wall surface at the upstream ends of the first branch flow path 18 and the second branch flow path 19. The branch position wall surface 22 is erected so as to be approximately perpendicular to the inner surface 11 as shown in Fig. 2. In other words, the second angle α2 that the branch position wall surface 22 makes with the inner surface 11 is approximately 90°.

[0024] The branch position wall surface 22 has a curved shape such as a circular arc shape when viewed in plan from the inner surface 11. Specifically, the branch position wall surface 22 is formed based on a circular arc with the branch point P1 located on the inside. In other words, the branch position wall surface 22 is a part of a cylindrical surface with an axis passing through the branch point P1 located on the inside.

[0025] The second angle α2 of the branch position wall surface 22 is not limited to approximately 90°, but may be any angle larger than the first angle α1 of the main flow path 17, for example, 45° to 90°.

[0026] Fig. 4 shows an enlarged view of the outlet opening 15b of the cooling passage 15 shown in Fig. 3. As shown in Fig. 4, preferably, the radius of curvature R1 of the branch position wall surface 22, the radius of curvature R2 of the downstream end of the first branch opening 15b2 of the first branch passage 18, and the radius of curvature R3 of the downstream end of the second branch opening 15b3 of the second branch passage 19 are the same. As a result, for example, when laser processing is used to form the first branch passage 18 and the second branch passage 19, a common laser spot diameter can be used at the branch position wall surface 22 and the downstream ends of both branch openings 15b2 and 15b3, making it unnecessary to adjust the spot diameter.

[0027] Also, preferably, a chamfered portion CR is provided at the position where the first branch opening 15b2 and the main flow passage outlet opening 15b1 intersect and at the position where the second branch opening 15b3 and the main flow passage outlet opening 15b1 intersect. The chamfered portion CR may be an R chamfer or a C chamfer. This relieves stress concentration and prevents cracks from occurring.

[0028] Fig. 5 shows a vertical cross section of the wall portion 9 corresponding to Fig. 2. As shown in Fig. 5, the wall portion 9 has a top coat layer 9c formed on the inner surface 11 side of a base material 9a via a bond layer 9b. The base material 9a is made of a heat-resistant alloy in general (e.g., Waspaloy, Inconel, etc.), the bond layer 9b is made of a metallic coating material (e.g., NiCrAlY, etc.), and the top coat layer 9c is made of a ceramic coating material (e.g., YSZ: yttrium stabilized zirconia, etc.).

[0029] The branch position wall surface 22 is formed up to the boundary position between the topcoat layer 9c and the bond layer 9b. As a result, the bottom 18a of the first branch flow path 18 and the bottom 19a of the second branch flow path 19 coincide with the boundary position between the topcoat layer 9c and the bond layer 9b. The base material 9a, the bond layer 9b, and the topcoat layer 9c are made of different materials, and therefore have different linear expansion coefficients. This may cause delamination. Therefore, as shown in FIG. 5, the branch position wall surface 22 is formed up to the boundary position between the topcoat layer 9c and the bond layer 9b. As a result, delamination between the topcoat layer 9c and the bond layer 9b at the branch position wall surface 22 can be suppressed.

[0030] Next, a method for processing the cooling flow passage 15 having the above configuration will be described. The processing method used is laser processing in which a high energy density laser is irradiated onto the wall portion 9 to melt and evaporate it.

[0031] First, the first branch flow channel 18 and the second branch flow channel 19 are formed (first step), and then the main flow channel 17 is formed (second step).

[0032] When forming the first branch flow passage 18 and the second branch flow passage 19, the laser light is irradiated in a direction having a second angle α2 (see FIG. 2) with respect to the inner surface 11. The processing with the laser light is limited to a predetermined position in the thickness direction of the wall portion 9, and the laser light is scanned in the directions of the second axis C2 and the third axis C3 (see FIG. 3) to form the first branch flow passage 18 and the second branch flow passage 19 in a crater shape that is a bottomed groove portion. The shape of the laser light at this time is made circular matching the radius of curvature R1 of the branch position wall surface 22. This allows the radius of curvature R1 of the branch position wall surface 22 to match the radius of curvature R2 of the downstream end of the first branch opening 15b2 of the first branch flow passage 18 and the radius of curvature R3 of the downstream end of the second branch opening 15b3 of the second branch flow passage 19 (see FIG. 4).

[0033] When forming the main flow channel 17, a laser beam is irradiated in a direction having a first angle α1 (see FIG. 2) with respect to the inner surface 11 of the wall portion 9 to form the main flow channel 17. The cross-sectional shape of the laser beam coincides with the cross-sectional shape of the main flow channel 17, and is, for example, circular.

[0034] In the first step of forming the first branch flow passage 18 and the second branch flow passage 19 as described above, the second angle α2 (approximately 90° in this embodiment) is made larger than the first angle α1 to form a branch position wall surface 22 having a cylindrical cross section with the branch point P1 (see FIG. 3) located on the inside. This results in removing the overhang portion 30 (see FIG. 6). As shown in FIG. 6, the overhang portion 30 is a thin portion that remains between the main flow passage 17 and the inner surface 11 after the main flow passage 17 is formed in the first step. By removing the overhang portion 30, damage during the processing of the cooling flow passage 15 and during the operation of the cooling wall structure 10 is prevented as much as possible.

[0035] The effects of the present embodiment described above are as follows. Film cooling of the cooling wall structure 10 is performed by flowing cooling air A1 through the cooling wall structure 10 whose inner surface 11 faces the high-temperature space S through which the combustion gas G flows.

[0036] The cooling passage 15 through which the cooling air A1 flows is inclined at a first angle α1 with respect to the inner surface 11, and the cooling air A1 flows along the inner surface 11 in the direction in which the combustion gas G flows from an outlet opening 15b formed in the inner surface 11, thereby film-cooling the inner surface 11 downstream of the outlet opening 15b.

[0037] The cooling flow passage 15 includes a main flow passage 17 and two branch flow passages 18, 19 that are branched from a midway position of the main flow passage 17 and provided on both sides of the main flow passage 17. The cooling air A1 flowing out from the main flow passage 17 to the high-temperature space S forms a counter rotating vortex pair (CRVP: a pair of positive and negative vorticity that reduces the wall adhesion of the cooling air A1). In response to this, an anti-CRVP is generated by the cooling air A1 flowing out from the branch flow passages 18, 19 on both sides of the main flow passage 17, suppressing the CRVP of the cooling air A1 flowing out from the main flow passage 17 and promoting adhesion of the cooling air A1 to the inner surface 11. This improves the cooling performance of the inner surface 11.

[0038] At the branch point P1, a branch position wall surface 22 is formed from the inner surface 11 to the main flow passage 17. The branch position wall surface 22 has a second angle α2 larger than the first angle α1, which is the inclination angle of the main flow passage 17, so that the outlet opening 15b formed by the main flow passage 17 is enlarged upstream. This diffuses the flow from the leading edge and further induces a wall-attached flow.

[0039] Since the second angle α2, which is the inclination angle of the branch position wall surface 22, is made larger than the first angle α1 of the main flow passage 17, the overhang portion 30, which is the wall portion in the vicinity of the upstream of the outlet opening 15b, can be removed. That is, if an opening is formed on the extension of the main flow passage 17 with the inclination of the first angle α1, the overhang portion 30, which has a thin wall thickness, will remain on the upstream side of the opening. In contrast, by forming the branch position wall surface 22 having the second angle α2 larger than the first angle α1, the thin overhang portion 30 can be removed. In this way, by removing the thin overhang portion 30, damage during the processing of the cooling flow passage 15 and during the operation of the cooling wall structure 10 can be prevented as much as possible, and durability can be improved.

[0040] By setting the second angle α2 to approximately 90°, the thin overhang portion can be effectively removed.

[0041] By forming the branch position wall surface 22 in a cylindrical shape, stress concentration can be alleviated, and the occurrence of cracks can be prevented.

[0042] A chamfered portion CR (see FIG. 4) is provided at the position where the outlet opening 15b formed by the main flow path 17 intersects with the first branch opening 15b2 and the second branch opening 15b3 formed by the branch flow paths 18 and 19. This makes it possible to reduce stress concentration and prevent cracks from occurring.

[0043] The branch flow paths 18, 19 are formed as bottomed grooves that are connected to the branch position wall surface 22 and are formed to the same depth as the branch position wall surface 22. This makes it possible to form the branch flow paths 18, 19 simultaneously with the formation of the branch position wall surface 22 by laser processing (first step), facilitating processing.

[0044] The arcuate shape of the branch position wall surface 22 and the arcuate shapes of the downstream ends of the branch flow paths 18 and 19 have the same radii of curvature R1, R2, and R3 (see FIG. 4). This makes processing easier. That is, when performing laser processing, a common laser spot diameter can be used, and adjustment of the spot diameter is not required.

[0045] The base material 9a, the bond layer 9b, and the topcoat layer 9c constituting the wall portion 9 are made of different materials, and therefore have different linear expansion coefficients. This may cause delamination. Therefore, the branch position wall surface 22 is formed up to the boundary between the topcoat layer 9c and the bond layer 9b. This makes it possible to suppress delamination between the topcoat layer 9c and the bond layer 9b at the branch position wall surface 22.

[0046] 7, the branch position wall surface 22 may be formed up to the boundary between the bond layer 9b and the base material 9a. This makes it possible to suppress delamination between the topcoat layer 9c and the bond layer 9b, and between the bond layer 9b and the base material 9a at the branch position wall surface 22.

[0047] 8, the branch position wall surface 22 may be formed to the inside of the base material 9a. This makes it possible to suppress delamination between the topcoat layer 9c and the bond layer 9b, and between the bond layer 9b and the base material 9a at the branch position wall surface 22.

[0048] <Variation 1> This embodiment can be modified as follows. In the cooling wall structure 10 of the present embodiment described above, the first branch passage 18 and the second branch passage 19 are crater-shaped with bottomed grooves. In contrast, in the cooling passage 15' of the cooling wall structure according to this modification, as shown in Fig. 9, the first branch passage 18' and the second branch passage 19' are shaped to have cylindrical bottoms 18a', 19a' like the main passage 17. The first branch passage 18' has a second axis C2' and extends from the branch point P1. The second branch passage 19' has a third axis C3' and extends from the branch point P1.

[0049] The first branch flow passage 18' and the second branch flow passage 19' have a first branch angle α3 and a second branch angle α4 that are the same magnitude when the inner surface 11 is viewed in a plan view. The first branch flow passage 18' and the second branch flow passage 19' are inclined at a first angle α1 that is the same as the first axis C1 of the main flow passage 17, as shown in Fig. 10.

[0050] The first branch flow path 18' and the second branch flow path 19' are formed by irradiating the laser light in a direction having a first angle α1 with respect to the inner surface 11. By using a laser light with a circular cross section, cylindrical bottoms 18a', 19a' are formed.

[0051] However, in the cooling wall structure 10' shown in Fig. 10, a branch position wall surface 22 having the second angle α2 is formed as in the first embodiment. The step of forming the branch position wall surface 22 is performed by irradiating the laser light in a direction having the second angle α2 with respect to the inner surface 11 at any timing before or after the step of forming the first branch flow passage 18' and the second branch flow passage 19'.

[0052] <Variation 2> This embodiment can be modified as follows. As shown in Figure 11, a cooling flow passage 15" of this modified example, the main flow passage 17" may be in a fan shape in which the flow passage cross-sectional area gradually increases toward the downstream side. The main flow passage 17" has a circular cross-section from the upstream side to a midpoint P2, and the flow passage cross-sectional area gradually increases from the midpoint P2 toward the downstream side. For ease of understanding, only the main flow passage 17" is shown in Figure 12.

[0053] Since the main flow passage 17'' has a shape in which the flow passage cross-sectional area gradually increases toward the downstream side, the flow is more diffused downstream and a wall-attached flow is formed, as compared with the case in which the main flow passage 17 has a circular hole shape with a constant diameter as shown in FIG. 2, and the film cooling efficiency can be further improved.

[0054] <Variation 3> The branch position wall surface 22" may have a shape as shown in FIG. 13. That is, in FIG. 3, the branch position wall surface 22 has a cylindrical cross section (see the dashed line in FIG. 13), but is not limited to such a cylindrical cross section, and may have a shape close to a flat surface, for example, as shown in FIG. 13. In this case, the first branch flow path 18" and the second branch flow path 19" have a larger width than the flow paths shown in FIG. 3 (see the dashed line in FIG. 13). Alternatively, the branch position wall surface may be a combination of a flat surface and a curved surface.

[0055] <Modification 4> As shown in Fig. 14, the overhang portion 30 may be removed from the topcoat layer 9c and the bond layer 9b, and the overhang portion 30 may be left only on the base material 9a. Also, as shown in Fig. 15, the overhang portion 30 may be removed from the topcoat layer 9c, and the overhang portion 30 may be left on the base material 9a and the bond layer 9b. The base material 9a and the bond layer 9b have a larger heat capacity than the topcoat layer 9c, and therefore have a lower risk of damage due to delamination or thermal stress concentration, so it is preferable to at least not leave the overhang portion 30 on the topcoat layer 9c.

[0056] In the above-described embodiment and each modified example, the cooling wall structure 10 is described on the assumption that it is used in a combustor, but the present disclosure is not limited to this and can be applied to high-temperature parts that come into contact with high-temperature gas, such as turbine blades.

[0057] The cooling wall structure, the high-temperature component including the cooling wall structure, and the method for manufacturing the cooling wall structure described in each of the above-described embodiments can be understood, for example, as follows.

[0058] A cooling wall structure (10) according to a first aspect of the present disclosure comprises a first wall surface (11) facing a high-temperature space (S) through which a high-temperature fluid (G) flows, and a cooling flow passage (15) inclined at a first angle with respect to the first wall surface and guiding a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows to cool the first wall surface downstream of the opening, wherein the cooling flow passage comprises a first flow passage (17) and branch flow passages (18, 19) branched from a branch position (P1) midway through the first flow passage and provided on each side of the first flow passage when the first wall surface is viewed in a plane, and at the branch position, a branch position wall surface is formed which is formed from the first wall surface to the first flow passage and has a second angle (α2) greater than the first angle (α1).

[0059] The cooling wall structure is cooled by flowing a cooling fluid such as air through the cooling wall structure, the first wall of which faces a high-temperature space through which a high-temperature fluid such as combustion gas flows. The cooling flow passage through which the cooling fluid flows is inclined at a first angle with respect to the first wall surface, and the cooling fluid flows along the first wall surface in the direction in which the high-temperature fluid flows from an opening formed in the first wall surface, thereby film-cooling the first wall surface downstream of the opening. The cooling flow path includes a first flow path and branch flow paths that branch off from a midway position of the first flow path and are provided on both sides of the first flow path. The cooling fluid flowing out of the first flow path into the high-temperature space forms a Counter Rotating Vortex Pair (CRVP: a pair of positive and negative vorticity that reduces the adhesion of the cooling fluid to the wall surface). In response to this, an Anti-CRVP is generated by the cooling fluid flowing out of the branch flow paths on both sides of the first flow path, suppressing the CRVP of the cooling fluid flowing out of the first flow path and promoting the adhesion of the cooling fluid to the first wall surface. This improves the cooling performance at the first wall surface. At the branching position, a branching position wall surface is formed from the first wall surface to the first flow path. The branching position wall surface has a second angle larger than the first angle, which is the inclination angle of the first flow path, so that the opening formed by the first flow path is enlarged upstream. This diffuses the flow from the leading edge and further induces a wall-attached flow. Since the second angle, which is the inclination angle of the branch position wall surface, is made larger than the first angle, it is possible to remove the wall portion between the first wall surface and the opening near the upstream side. In other words, if the opening is formed on the extension of the first flow path with the inclination at the first angle, an overhang portion with a thin wall thickness will remain on the upstream side of the opening. In contrast, by forming the branch position wall surface with the second angle larger than the first angle, it is possible to remove the thin overhang portion. In this way, by removing the thin overhang portion, it is possible to prevent damage during processing of the cooling flow path and operation of the cooling wall structure as much as possible, and it is possible to improve durability. The wall surface at the branching position is not limited to a surface where the entire upper surface of the flow path is open.

[0060] In a cooling wall structure according to a second aspect of the present disclosure, in the first aspect, the second angle is set to be equal to or greater than 45° and equal to or less than 90°.

[0061] By setting the second angle to 45° or more and 90° or less, the thin overhang portion can be effectively removed. The second angle is preferably as close to 90° as possible, and is, for example, set to 60° or more, more preferably 80° or more.

[0062] A cooling wall structure according to a third aspect of the present disclosure is such that in the first or second aspect, the branching position wall surface is formed in an arc shape when viewed in plan from the first wall surface.

[0063] By forming the wall surface at the branching position in an arc shape, stress concentration can be alleviated, thereby preventing the occurrence of cracks.

[0064] The cooling wall structure according to the fourth aspect of the present disclosure, in any one of the first to third aspects, has a chamfered portion (CR) at a position where an opening formed in the first wall surface by extension of the first flow path intersects with an opening formed in the first wall surface by extension of the branch flow path.

[0065] A chamfer (R or C surface) is provided at the position where the opening formed by the first flow path intersects with the opening formed by the branch flow path, which reduces stress concentration and prevents cracks from occurring.

[0066] The cooling wall structure according to the fifth aspect of the present disclosure, in any one of the first to fourth aspects, is such that the branch position wall surface is arc-shaped when viewed in a plane from the first wall surface, and the arc shape of the branch position wall surface has the same radius of curvature (R1, R2, R3) as the arc shape formed at the downstream end of the branch flow path.

[0067] The radius of curvature of the arc shape of the wall surface at the branch position and the arc shape of the downstream end of the branch flow path are the same. This makes processing easier. For example, when forming the branch flow path by laser processing, a common laser spot diameter can be used for the wall surface at the branch position and the downstream end of the branch flow path, making it unnecessary to adjust the spot diameter.

[0068] A cooling wall structure according to a sixth aspect of the present disclosure, in any one of the first to fifth aspects, comprises a base material (9a), a bond layer (9b) formed on a surface of the base material, and a top coat layer (9c) formed on the surface of the bond layer, wherein the first wall surface is the surface of the top coat layer, and the branch position wall surface is formed up to a boundary position between the top coat layer and the bond layer.

[0069] The base material, the bond layer, and the topcoat layer are made of different materials, and therefore have different linear expansion coefficients. This can lead to delamination. Therefore, the branching wall is formed up to the boundary between the topcoat layer and the bond layer. This makes it possible to suppress delamination between the topcoat layer and the bond layer at the branching wall.

[0070] A cooling wall structure according to a seventh aspect of the present disclosure, in any one of the first to sixth aspects, comprises a base material, a bond layer formed on a surface of the base material, and a top coat layer formed on the surface of the bond layer, wherein the first wall surface is the surface of the top coat layer, and the branch position wall surface is formed up to a boundary position between the bond layer and the base material.

[0071] Since the branching position wall surface is formed up to the boundary position between the bond layer and the base material, it is possible to suppress interlayer delamination between the top coat layer and the bond layer, and between the bond layer and the base material, at the branching position wall surface.

[0072] The cooling wall structure according to the eighth aspect of the present disclosure, in any one of the first to sixth aspects, comprises a base material, a bond layer formed on a surface of the base material, and a top coat layer formed on the surface of the bond layer, wherein the first wall surface is the surface of the top coat layer, and the branch position wall surface is formed up to the base material.

[0073] Since the wall surface at the branching position is formed up to the base material, it is possible to suppress delamination between the topcoat layer and the bond layer, and between the bond layer and the base material, at the wall surface at the branching position.

[0074] The cooling wall structure according to a ninth aspect of the present disclosure is, in any one of the first to eighth aspects, such that each of the branch flow paths is a bottomed groove portion that is connected to the branch position wall surface and is formed at the same depth as the branch position wall surface.

[0075] The branch flow path is a bottomed groove that is connected to the branch position wall surface and is formed to the same depth as the branch position wall surface. This makes it possible to form the branch flow path at the same time as forming the branch position wall surface, making processing easier.

[0076] A cooling wall structure according to a tenth aspect of the present disclosure is based on any one of the first to ninth aspects, wherein each of the branch flow paths is a cylindrical bottomed groove.

[0077] A cooling wall structure (15") according to an eleventh aspect of the present disclosure is configured such that in any one of the first to ninth aspects, the first flow path (17") has a shape in which the flow path cross-sectional area gradually widens toward the downstream side.

[0078] The first flow passage is shaped so that the cross-sectional area gradually widens toward the downstream side (for example, a fan shape). This allows the flow to be diffused further downstream and a wall-attached flow to be formed, further improving the film cooling efficiency, compared to when the first flow passage is shaped like a round hole.

[0079] A high-temperature component (1) according to a first aspect of the present disclosure includes the cooling wall structure according to any one of the first to eleventh aspects.

[0080] The high-temperature parts are, for example, parts that come into contact with high-temperature gases such as combustion gases, and more specifically, combustors and turbine blades used in aircraft engines are included.

[0081] A manufacturing method for a cooling wall structure according to a first aspect of the present disclosure includes a first wall surface facing a high-temperature space through which a high-temperature fluid flows, and a cooling flow path inclined at a first angle with respect to the first wall surface and guiding a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows to cool the first wall surface downstream of the opening, wherein the cooling flow path includes a first flow path and branch flow paths branched from a branching position midway through the first flow path and provided on each side of the first flow path when the first wall surface is viewed in a plane, and at the branching position, a branching position wall surface is formed that is formed from the first wall surface to the first flow path and has a second angle larger than the first angle, the manufacturing method for a cooling wall structure includes a first step of forming each of the branching flow paths together with the branching position wall surface by laser processing, and a second step of forming the first flow path by laser processing.

[0082] After forming each branch flow path by laser processing, the first flow path is formed by laser processing. Since the wall surface at the branch position is also processed in the first process, the manufacturing process can be simplified. [Explanation of symbols]

[0083] 1 Combustor (high temperature parts) 3 Main casing 5 Combustor liner 9 Wall 9a Base material 9b Bond layer 9c Topcoat layer 10 Cooling wall structure 11 Inner surface (first wall) 12 Outer surface 15,15',15” Cooling Channels 15a Inlet opening 15b,15b' Exit opening 15b1 Main channel outlet opening 15b2 First branch opening 15b3 Second branch opening 17,17” Main channel 18,18' First branch channel (branch channel) 18a,18a',18” bottom 19,19',19” Second branch channel (branch channel) 19a,19a' bottom 22,22” Branching point wall 30 Overhang A. Compressed air A1 Cooling air C1 1st axis C2,C2' 2nd axis C3,C3' 3rd axis D1 Branch position F fuel FL flame S High temperature space P1 Junction R1,R2,R3 Radius of curvature CR Chamfer x Longitudinal direction of the combustor liner (main flow direction of combustion gas) y Wall thickness direction α1 1st angle α2 2nd angle α3 First branch angle α4 Second branch angle

Claims

1. a first wall surface facing a high-temperature space through which a high-temperature fluid flows; a cooling flow passage that is inclined at a first angle with respect to the first wall surface and that guides a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows, thereby cooling the first wall surface downstream of the opening; Equipped with the cooling flow path includes a first flow path and branch flow paths branched from a branch position midway through the first flow path and provided on both sides of the first flow path when the first wall surface is viewed in a plan view, A cooling wall structure in which a branch position wall surface is formed at the branch position from the first wall surface to the first flow path and has a second angle larger than the first angle.

2. The cooling wall structure according to claim 1 , wherein the second angle is greater than or equal to 45° and less than or equal to 90°.

3. The cooling wall structure according to claim 1 , wherein the branch position wall surface has an arc shape when viewed from above from the first wall surface.

4. 2. The cooling wall structure according to claim 1, wherein a chamfer is provided at a position where an opening formed in the first wall surface by extending the first flow path intersects with an opening formed in the first wall surface by extending the branch flow path.

5. The branch position wall surface has an arc shape when viewed in a plan view from the first wall surface, 5. The cooling wall structure according to claim 1, wherein the arc shape of the branch position wall surface has the same radius of curvature as the arc shape formed at the downstream end of the branch flow passage.

6. A base material; a bond layer formed on a surface of the base material; a topcoat layer formed on the surface of the bond layer; Equipped with The first wall surface is a surface of the top coat layer, 5. The cooling wall structure according to claim 1, wherein the branching position wall surface is formed up to a boundary position between the top coat layer and the bond layer.

7. A base material; a bond layer formed on a surface of the base material; a topcoat layer formed on the surface of the bond layer; Equipped with The first wall surface is a surface of the top coat layer, 5. The cooling wall structure according to claim 1, wherein the branching position wall surface is formed up to a boundary position between the bond layer and the base material.

8. A base material; a bond layer formed on a surface of the base material; a topcoat layer formed on the surface of the bond layer; Equipped with The first wall surface is a surface of the top coat layer, The cooling wall structure according to claim 1 , wherein the branching position wall surface is formed up to the base material.

9. 5. The cooling wall structure according to claim 1, wherein each of the branch passages is a bottomed groove that is connected to the branch position wall surface and has the same depth as the branch position wall surface.

10. 5. The cooling wall structure according to claim 1, wherein each of the branch passages is a cylindrical groove with a bottom.

11. 5. The cooling wall structure according to claim 1, wherein the first flow passage has a cross-sectional area that gradually increases toward the downstream side.

12. A high-temperature component comprising the cooling wall structure according to any one of claims 1 to 4.

13. a first wall surface facing a high-temperature space through which a high-temperature fluid flows; a cooling flow passage that is inclined at a first angle with respect to the first wall surface and that guides a cooling fluid from an opening formed in the first wall surface in a direction in which the high-temperature fluid flows, thereby cooling the first wall surface downstream of the opening; Equipped with the cooling flow path includes a first flow path and branch flow paths branched from a branch position midway through the first flow path and provided on both sides of the first flow path when the first wall surface is viewed in a plan view, a branch position wall surface is formed at the branch position, the branch position wall surface being formed from the first wall surface to the first flow path and having a second angle larger than the first angle, a first step of forming each of the branch flow paths together with the branch position wall surface by laser processing; A second step of forming the first flow path by laser processing; A method for manufacturing a cooling wall structure having the above structure.

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