Wall member and manufacturing method therefor

Abstract

To manufacture, using the AM method, a wall member of a combustor for a gas turbine and the like, which comprises a cooling hole inclined to a lamination direction of metal by the AM method.SOLUTION: An end wall 102 is provided with a cooling hole 108 extending from a first surface 102A to a second surface 102B different from the first surface 102A. The cooling hole 108 is inclined at a predetermined inclination angle α in a predetermined inclination direction relative to a direction perpendicular to the first surface 102A. When the inclination direction is defined as a vertical direction, a cross-sectional shape of a portion of the cooling hole 108 on the second surface 102B side includes a portion 108F that forms a crest shape that is sharper than a semicircular shape toward a side away from the first surface 102A.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a wall member and a method for manufacturing the same. [Background technology]

[0002] In a combustor for generating combustion gas in a gas turbine engine, cooling holes are provided that penetrate the wall of a liner (housing) that defines the combustion chamber, and the cooling air ejected from the cooling holes into the combustion chamber flows along the wall surface of the liner on the combustion chamber side, thereby enabling the liner to be cooled effectively.

[0003] In order to effectively cool the liner with the cooling air ejected from the cooling holes into the combustion chamber, it is preferable that the cooling air flows in a layer along the wall surface of the liner on the combustion chamber side.

[0004] If the flow velocity of the cooling air ejected from the cooling holes into the combustion chamber is high and the turbulent component is large, the cooling air tends to separate from the liner wall surface, hindering cooling of the liner wall. Therefore, it is preferable to reduce the flow velocity of the cooling air as much as possible as it flows through the cooling holes. To achieve this, it is preferable that the cross-sectional area of the cooling holes gradually increases from the inlet to the outlet, thereby promoting the deceleration of the cooling air flowing through the cooling holes. This allows the liner to be cooled effectively. It is known to form the cooling holes at an angle with respect to the thickness direction of the liner wall in order to cause the cooling air to flow along the liner wall surface (e.g., Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-17497 [Patent Document 2] Japanese Patent Publication No. 2022-150946 Summary of the Invention [Problem to be solved by the invention]

[0006] To enhance the cooling effect in such structures, it is desirable to form cooling holes with complex shapes. Therefore, additive manufacturing (AM) methods, which involve laminating metal layers, have been considered for manufacturing combustor liners. If the cooling holes penetrate the wall thickness, they can be formed without any problems by sequentially laminating metal layers from bottom to top in the wall thickness direction. However, if the cooling holes are inclined relative to the metal lamination direction, there is a risk that the unhardened metal forming the upper side of the cooling hole will drip due to gravity, limiting the possible inclination angle of the cooling holes. In particular, if the cooling holes have a horizontally elongated cross-sectional shape, such as an oval, or if the cooling holes have a large cross-sectional area, the surface forming the upper side of the cooling hole will have a small curvature and be horizontally elongated, further increasing the tendency for metal to drip, making it difficult to manufacture liners using AM.

[0007] In view of the above background, an object of the present invention is to enable suitable manufacturing, by an AM method, of wall members for gas turbine combustors and the like, which have through holes inclined with respect to the thickness direction of the wall. [Means for solving the problem]

[0008] In order to solve the above problem, one aspect of the present invention is a wall member having a through hole (108) extending from a first surface (102A) of a wall (102) to a second surface (102B) different from the first surface, wherein the through hole is inclined at a predetermined inclination angle (α) in a predetermined inclination direction with respect to a direction perpendicular to the first surface, and when the inclination direction is taken as the vertical direction, the cross-sectional shape of the through hole on the second surface side includes a portion (108F) that forms a mountain shape that is sharper than a semicircle toward the side away from the first surface.

[0009] According to this aspect, when the combustor wall is formed by laminating layers using the AM method with the first surface facing downward, the upper surface of the through hole has a sharper mountain shape than a semicircle, and the through hole can be formed suitably even when the inclination angle of the through hole is relatively large.

[0010] In the above aspect, the portion of the through hole on the second surface side may be wider than the portion of the through hole on the first surface side.

[0011] According to this aspect, even if there is a restriction on the dimension in the thickness direction, it is possible to form a through hole with a relatively large cross-sectional area.

[0012] In the above aspect, the through holes may be cooling holes that allow a cooling medium to flow from the first surface side toward the second surface side.

[0013] According to this aspect, by making the through-holes have a flat cross-sectional shape, it is possible to form a laminar flow of the cooling medium.

[0014] In the above aspect, the cooling hole may be a shaped hole that widens toward the second surface side.

[0015] According to this aspect, the laminated structure can be suitably formed by AM. In particular, the shaped holes can reduce the inflow speed of the cooling medium, enabling suitable cooling.

[0016] In the above aspect, the downstream side of the cooling hole may have a larger inclination angle (β) on the second surface side than on the first surface side in a vertical cross-sectional view.

[0017] According to this aspect, the cooling medium tends to flow more easily along the second surface, enabling suitable cooling.

[0018] In the above aspect, the through hole may have a cross-sectional shape such that the width in the lateral direction of the through hole on the first surface side gradually increases toward the second surface side.

[0019] According to this aspect, even if there is a restriction on the dimension in the thickness direction, it is possible to form a through hole with a particularly large cross-sectional area.

[0020] In the above aspect, the cross-sectional shape of the through-hole may include a pair of straight line portions that form an included angle (δ) of 90 degrees or less at the upper part of the through-hole.

[0021] This embodiment particularly effectively reduces the tendency of the unhardened metal forming the upper side of the through hole to drip down due to gravity.

[0022] In the above aspect, the wall member may be a member forming a liner of a combustor for a gas turbine.

[0023] According to this aspect, a gas turbine combustor having through-holes inclined with respect to the thickness direction of the liner wall can be suitably manufactured by the AM method.

[0024] In order to solve the above problem, one aspect of the present invention provides a method for manufacturing the wall member described above, in which an AM method is carried out with the first surface side facing downward.

[0025] According to this aspect, a wall member having through holes inclined with respect to the direction in which metal is stacked by the AM method can be suitably manufactured by the AM method. [Effects of the Invention]

[0026] According to the above aspect, a wall member having through holes inclined with respect to the thickness direction of the wall can be suitably manufactured by the AM method. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a longitudinal cross-sectional view showing a power-generating gas turbine engine to which a gas turbine combustor according to the present invention is applied. [Figure 2] FIG. 1 is a vertical cross-sectional perspective view showing a portion of a gas turbine combustor according to an embodiment of the present invention. [Figure 3] FIG. 1 is an enlarged vertical cross-sectional view of a cooling hole of a gas turbine combustor according to an embodiment of the present invention. [Figure 4] 4 is a cross-sectional view taken along line IV-IV of FIG. [Figure 5]Cross-sectional view along line VV in Figure 3 [Figure 6] 3. A cross-sectional view taken along line VI-VI of FIG. [Figure 7] FIG. 1 is an enlarged perspective view of a cooling hole of a combustor for a gas turbine according to an embodiment of the present invention; [Figure 8] FIG. 1 is an enlarged perspective view of an end wall and a connecting portion of a combustor for a gas turbine according to an embodiment of the present invention, as viewed from the combustion chamber side. DETAILED DESCRIPTION OF THE INVENTION

[0028] Fig. 1 is a cross-sectional view of a power-generating gas turbine system 10 to which a gas turbine combustor according to this embodiment is applied. As shown in Fig. 1, the power-generating gas turbine system 10 has a radial compressor 14 and a radial turbine 16 that are coaxially connected to each other by a rotating shaft 12. An input shaft of a generator 20 is connected to the rotating shaft 12.

[0029] The power generating gas turbine system 10 includes a front end plate 22 located on the side of the generator 20, a front housing 24, a middle housing 26, and a rear housing 28, arranged in this order in the axial direction.

[0030] The radial compressor 14 has a compressor liner 32 attached to the front housing 24 and defining a compressor chamber 30, a diffuser fixing member 36 that fixes a diffuser 34, and an air intake guide member 38 attached to the front end plate 22. The air intake guide member 38 cooperates with the compressor liner 32 to define an air intake port 40. A compressor rotor 42 attached to the rotary shaft 12 is rotatably disposed in the compressor chamber 30. The compressor rotor 42 is rotationally driven by the rotary shaft 12, which is the output shaft of the radial turbine 16.

[0031] The radial compressor 14 takes in air (outside air) from an air intake 40, compresses and pressurizes the air by the rotation of a compressor rotor 42, and ejects the compressed and pressurized air (compressed air) into the diffuser 34.

[0032] The combustor 18 is disposed within the rear housing 28 and arranged around the central axis of the rotary shaft 12. The rear housing 28 includes a portion that defines a compressed air chamber 44 that directs compressed air from the diffuser 34 to the combustor 18. The combustor 18 defines a combustion chamber 46. Fuel injection nozzles 48 are attached to various portions of the combustor 18. The fuel injection nozzles 48 inject fuel into the combustion chamber 46.

[0033] In the combustion chamber 46, a mixture of fuel injected into the combustion chamber 46 by a fuel injection nozzle 48 and compressed air from the radial compressor 14 is combusted, generating high-temperature combustion gas (compressed fluid). A turbine nozzle 50 is provided at the combustion gas outlet 112 of the combustor 18.

[0034] The radial turbine 16 has a turbine chamber 52 that is defined by the inner portion of the rear housing 28 and communicates with the combustion gas outlet 112 of the combustor 18. The turbine chamber 52 is separated from the compressor chamber 30 by a partition member 54. The side of the turbine chamber 52 that is away from the partition member 54 is defined by a shroud 56. A radial turbine impeller 58 that is integrally formed with the rotary shaft 12 is rotatably disposed in the turbine chamber 52.

[0035] The turbine nozzle 50 is annular in shape so as to surround the radial turbine impeller 58, and injects combustion gas radially inward and circumferentially toward the radial turbine impeller 58. The radial turbine impeller 58 is rotationally driven by the combustion gas injected from the turbine nozzle 50. The combustion gas that has rotationally driven the radial turbine impeller 58 is discharged as exhaust gas into the atmosphere from an exhaust gas passage 60 defined by a tubular member connected to the rear end of the rear housing 28.

[0036] A rotor shaft 62 of the generator 20 is connected to the rotary shaft 12. As a result, the generator 20 is rotationally driven by the rotary shaft 12 of the radial turbine 16 to generate electricity.

[0037] The combustor 18 will be described in detail with reference to FIGS.

[0038] The combustor 18 is an annular combustor and, as shown in Fig. 1, has a liner (housing) 100 arranged approximately concentrically within the cylindrical compressed air chamber 44. The liner 100 constitutes a wall member and, as shown in Fig. 2, includes an annular end wall 102 extending in a direction approximately perpendicular to the axial direction, an outer peripheral wall 104 extending in the axial direction and having a substantially cylindrical shape, the outer peripheral wall 104 being connected to the outer peripheral edge of the end wall 102 at a first end 104A so as to be continuous with the outer peripheral edge of the end wall 102, and an inner peripheral wall 106 also extending in the axial direction and having a substantially cylindrical shape, the inner peripheral wall 106 being connected to the inner peripheral edge of the end wall 102 at a first end 106A so as to be continuous with the inner peripheral edge of the end wall 102, thereby defining the donut-shaped combustion chamber 46 around the central axis.

[0039] The liner 100 is manufactured by AM, which builds up metal layers from bottom to top, with the end walls 102 facing downward and the central axis of the liner 100 extending vertically. In this embodiment, the liner 100 is integrally formed as a whole by layering layers, but it is also possible to form the outer peripheral wall 104, the inner peripheral wall 106, and the end walls 102 separately and then join the respective parts together.

[0040] The outer surface of the liner 100 is exposed to the flow of compressed air in the compressed air chamber 44 and is cooled using the compressed air as a cooling medium.

[0041] Mounting portions 110 for the fuel injection nozzles 48 are formed at predetermined intervals in the circumferential direction on the end wall 102. Each fuel injection nozzle 48 mixes air and fuel from the compressed air chamber 44 and injects the resulting mixture into the combustion chamber 46. In the combustion chamber 46, the mixture combusts, generating high-temperature combustion gases.

[0042] The outer peripheral wall 104 and the inner peripheral wall 106 have first ends 104A, 106A that are continuous with the end wall 102, and second ends 104B, 106B that are opposite in the axial direction to the first ends 104A, 106A. These second ends 104B, 106B cooperate with each other to define an annular combustion gas outlet 112 that opens radially inward. The combustion gas outlet 112 is connected to the turbine nozzle 50 (see FIG. 1) of the radial turbine 16 to supply fuel gas to the radial turbine 16.

[0043] The combustion gases flow through the combustion chamber 46 in a flow direction F indicated by the arrows in FIG. 2 from the end wall 102 toward the combustion gas outlet 112 .

[0044] Each of the outer peripheral wall 104 and the inner peripheral wall 106 has a plurality of upright wall portions 114 extending circumferentially and spaced apart at predetermined intervals in the axial direction, and an inclined wall portion 116 extending between adjacent upright wall portions 114 in the axial direction and continuing to the corresponding upright wall portion 114. In detail, as shown in Fig. 2, each inclined wall portion 116 extends in an annular shape around the central axis between an outer edge portion 114A (side away from the combustion chamber 46) in the radial direction of the adjacent upright wall portion 114 on the upstream side with respect to the flow direction F of the combustion gas, and an inner edge portion 114B (side close to the combustion chamber 46) in the radial direction of the adjacent upright wall portion 114 on the downstream side.

[0045] A plurality of cooling holes 120 are formed at predetermined intervals in the circumferential direction through each upright wall portion 114. Each cooling hole 120 has a substantially constant cross section in the longitudinal direction on the upstream side, but forms a shaped hole that gradually expands along the flow direction on the downstream side.

[0046] 2 to 8, a plurality of cooling holes (through-holes) 108 are formed penetrating the end wall 102. FIG. 3 is a vertical cross-sectional view perpendicular to the wall surface of the end wall 102 and along the inclination direction of the cooling holes 120. In this embodiment, a wall surface 102A of the end wall 102 facing the compressed air chamber 44 (hereinafter, this may be referred to as a first surface 102A) and a wall surface 102B of the end wall 102 facing the combustion chamber 46 (hereinafter, this may be referred to as a second surface 102B) are substantially parallel to each other.

[0047] Each cooling hole 108 is a through hole that extends from a first surface 102A of the end wall 102 to a second surface 102B different from the first surface 102A, and compressed air, which serves as a cooling medium, flows from the first surface 102A side toward the second surface 102B side as cooling air.

[0048] Each cooling hole 108 has a passage shape including an upstream portion 108A on the compressed air chamber 44 side, i.e., on the first surface 102A side, which has a substantially constant inner diameter along the longitudinal direction of the cooling hole 108, and a downstream portion 108B on the combustion chamber 46 side, i.e., on the second surface 102B side, which widens in the front-to-rear and left-to-right directions (lateral direction) from the compressed air chamber 44 side toward the combustion chamber 46, i.e., toward the downstream side, and constitutes a shaped hole similar to the cooling hole 120. The upstream portion 108A of the cooling hole 108 is set to an inner diameter that prevents unhardened metal from dripping due to gravity when the liner 100 is manufactured by the AM method.

[0049] 3, in the longitudinal cross-sectional view, the downstream portion 108B of the cooling hole 108 has an upper edge 108C (second surface side) that is coextensive with the upper edge 108C of the upstream portion 108A, but a lower edge 108E (first surface side) that is more inclined than the lower edge 108D of the upstream portion 108A. Specifically, the inclination angle α of the central axis C of the upstream portion 108A relative to the normal (thickness direction) of the first surface 102A may be 35 to 75 degrees, and preferably is approximately 60 degrees. The inclination angle β of the lower edge 108E of the downstream portion 108B relative to the normal to the first surface 102A is larger than the inclination angle α of the upstream portion 108A and may be 40 to 85 degrees, and preferably is approximately 70 degrees.

[0050] As shown in FIGS. 4 to 7, the downstream portion 108B of the cooling hole 108 has a substantially flat surface on the side of the lower edge 108E that is generally flared laterally. When viewed from a direction perpendicular to the longitudinal direction of the cooling hole 108, the lateral divergence angle δ (see FIG. 6) of the downstream portion 108B on the side of the lower edge 108E may be 5 to 45 degrees, and is preferably approximately 20 degrees. The upper edge 108C of the downstream portion 108B of the cooling hole 108 has a shape that includes a substantially rectangular portion 108G that is rounded on the side of the lower edge 108E and a mountain-shaped portion 108F that has a sharper mountain shape (pent roof shape) than a semicircular shape toward the side away from the lower edge 108E. The mountain-shaped portion 108F has a substantially isosceles triangle shape with the substantially rectangular portion 108G as its base and a pair of oblique sides (straight portions) on the side of the upper edge 108C. The angle γ (see FIG. 5) of the oblique side of the angled portion 108F may be 70 degrees to 110 degrees, and preferably approximately 90 degrees.

[0051] The portion of cooling hole 108 on the first surface 102A side is wider than the portion on the second surface 102B side, so that even if there is a constraint on the dimension in the thickness direction, it is possible to form cooling hole 108 with a relatively large cross-sectional area. In particular, in the cross-sectional shape of cooling hole 108, the lateral width of cooling hole 108 on the first surface 102A side gradually increases toward the second surface 102B side, so that even if there is a constraint on the dimension in the thickness direction, it is possible to form cooling hole 108 with an especially large cross-sectional area.

[0052] Because cooling hole 108 has a flat cross-sectional shape on the side of lower edge 108E of downstream portion 108B, when compressed air serving as a cooling medium flows as cooling air from first surface 102A toward second surface 102B, it is possible to suitably form a layered flow of cooling air along second surface 102B of end wall 102. Because cooling hole 108 is a shaped hole having the above-described shape, it is possible to reduce the inflow speed of cooling air into combustion chamber 46, enabling suitable cooling.

[0053] Each cooling hole 108 may be formed through the end wall 102 so as to be inclined in a direction intermediate between the circumferential direction and the radial direction when viewed in the direction shown in Fig. 8. In this embodiment, the cooling holes 108 are arranged so that cooling air is ejected in a substantially counterclockwise direction on the outer edge side of the end wall 102 and in a substantially clockwise direction on the inner edge side of the end wall 102. The arrangement of the cooling holes 108 may be set so as to prevent hot spots from occurring in the end wall 102.

[0054] As described above, the cooling holes 108 provided in the end wall 102 have a relatively complex shape, and therefore, it is difficult to manufacture them using conventional manufacturing methods such as cutting, casting, laser drilling, electrical discharge machining, etc. Therefore, in this embodiment, the liner 100 of the combustor 18 is manufactured by an AM method, which forms a shape by laminating metal.

[0055] 3, the metal is layered from bottom to top with the end wall 102 serving as the bottom wall. Although the cooling holes 108 are inclined relative to the vertical direction, the upper sides of the cooling holes 108 have a mountain-shaped configuration due to the mountain-shaped portions 108F, as described above, so there is no risk of the molten metal dripping. In this case, the outer peripheral wall 104 and the inner peripheral wall 106 can be manufactured separately from the end wall 102 by the same or another method and then integrated with each other, or the outer peripheral wall 104 and the inner peripheral wall 106 can be formed integrally with the end wall 102.

[0056] If the liner 100 is formed by laminating layers using the AM method with the first surface 102A of the end wall 102 facing downward, the upper side surface (the surface on the side of the upper edge 108C) of the cooling hole 108 of this embodiment described above has a sharper peak shape than a semicircular shape, so that the cooling hole 108 can be suitably formed even when the inclination angle is relatively large. The cooling hole 108 of the above shape can increase the passage cross-sectional area while avoiding the difficulty of molding when manufacturing the liner 100 using the AM method.

[0057] Although the description of the specific embodiment has been completed above, the present invention is not limited to the above embodiment and can be implemented in a wide variety of modifications. For example, the cooling holes 108 are not limited to through-holes that penetrate the end wall 102 of the combustor 18, but may be through-holes that are provided in passage members for various purposes and in various applications, with the end wall 102 serving as a passage member.

[0058] Furthermore, the combustor 18 is not limited to an annular type, but may be a can type. Furthermore, the combustor 18 is not limited to a combustor for a gas turbine engine for power generation, but may be applied to combustors for various gas turbine engines, such as combustors for aircraft gas turbine engines.

[0059] The wall member according to the present invention is not limited to the liner 100 of the combustor 18, but may be any type of wall member having through holes inclined with respect to the direction of the wall thickness, such as a turbine nozzle or a turbine blade. [Explanation of symbols]

[0060] 16: Radial turbine 100: Liner (wall material) 102: End wall 102A: 1st surface (wall surface) 102B: Second floor (wall) 108: Cooling hole (through hole) 108F: Mountain section (sharp mountain-shaped section) α: Inclination angle β: Inclination angle δ: Including angle

Claims

1. A wall member having a through hole provided from a first surface to a second surface different from the first surface, the through hole is inclined at a predetermined inclination angle in a predetermined inclination direction with respect to a direction perpendicular to the first surface, A wall member in which, when the inclination direction is vertical, the cross-sectional shape of the through hole includes a portion on the second surface side of the through hole that forms a sharper mountain shape than a semicircle toward the side away from the first surface.

2. The wall member according to claim 1 , wherein a portion of the through hole on the first surface side is wider than a portion of the through hole on the second surface side.

3. The wall member according to claim 2 , wherein the through-hole is a cooling hole through which a cooling medium flows from the first surface side to the second surface side.

4. The wall member according to claim 3 , wherein the cooling holes are shaped holes that are enlarged toward the second surface side.

5. The wall member according to claim 4 , wherein the downstream side of the cooling hole has a larger inclination angle on the second surface side than on the first surface side in a vertical cross-sectional view.

6. The wall member according to claim 1 or 2, wherein the cross-sectional shape of the through hole is such that the lateral width of the through hole on the first surface side gradually increases toward the second surface side.

7. 3. The wall member according to claim 1, wherein the cross-sectional shape of the through hole includes a pair of straight line portions at an upper portion of the through hole that form an angle of 90 degrees or less.

8. 3. A wall member according to claim 1, wherein the wall member is a member forming a liner of a combustor for a gas turbine.

9. A method for manufacturing a wall member according to any one of claims 1 to 7, comprising the steps of: A manufacturing method in which the AM method is performed with the first surface side facing downward.

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