Gas turbine stator blade and gas turbine

Abstract

This gas turbine stator blade is provided with: a leading edge partition wall that divides a blade inner cavity into a leading edge-side cavity and a trailing edge-side cavity; a negative pressure surface-side partition wall integrally formed with the blade main body, dividing the leading edge-side cavity into a negative pressure surface-side cavity and a pressure surface-side cavity, and in which a negative pressure surface-side impingement cooling hole is formed; and a tubular pressure surface-side insert which is inserted into the pressure surface-side cavity so that a first gap is provided between the tubular pressure surface-side insert and the pressure surface-forming wall and a second gap is provided between the tubular pressure surface-side insert and the negative pressure surface-side partition wall, and in which a pressure surface-side impingement cooling hole is formed. At least a portion of the cooling air passing through the pressure surface side impingement cooling hole passes through the first gap, the second gap, and the negative pressure surface side impingement cooling hole to cool the negative pressure surface forming wall.

Description

Technical Field

[0001] The invention relates to a gas turbine stationary blade and a gas turbine.

[0002] This application claims priority based on Japanese Patent Application No. 2022-106933 filed with the Japan Patent Office on July 1, 2022, and the contents of which are incorporated herein by reference. Background Art

[0003] Patent document 1 discloses a structure for reducing the amount of cooling air used to cool a gas turbine stator blade. In the blade body of the gas turbine stator blade, a blade inner cavity is formed between a negative pressure surface forming wall and a pressure surface forming wall, and the blade inner cavity is divided into a leading edge side cavity and a leading edge partition wall of a trailing edge side cavity extending from the inner surface of the negative pressure surface forming wall to the inner surface of the pressure surface forming wall. A hollow insert is arranged on the pressure surface side and the negative pressure surface side of the leading edge side cavity, respectively. A portion of the cooling air ejected from the impact cooling hole of the insert arranged on the pressure surface side toward the inner surface of the pressure surface forming wall of the blade body flows along the inner surface of the blade body and once introduced into the inside of the insert arranged on the negative pressure surface side, ejected from the impact cooling hole of the insert arranged on the negative pressure surface side toward the inner surface of the negative pressure surface forming wall, and then discharged to the outside of the blade body from the film cooling hole formed in the negative pressure surface forming wall.

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 5022097 Summary of the invention

[0007] Technical issues to be solved by the invention

[0008] In the gas turbine stator blade described in Patent Document 1, in order to prevent a portion of the cooling air ejected from the impact cooling holes of the insert arranged on the pressure surface side toward the inner surface of the pressure surface forming wall of the blade body from flowing into the film cooling holes of the negative pressure surface instead of flowing into the insert on the negative pressure surface side, in the leading edge side cavity, a rib-like wall protruding from the inner surface of the blade body toward the insert on the negative pressure surface side and a rib-like wall protruding from the leading edge partition wall toward the insert on the negative pressure surface side are arranged on both sides with the insert on the negative pressure surface side sandwiched therebetween.

[0009] However, since the rib-shaped wall and the insert on the negative pressure surface side are formed of different parts, cooling air leaks from the gap between the rib-shaped wall and the insert on the negative pressure surface side, thereby reducing the effect of impingement cooling on the inner surface of the negative pressure surface forming wall. Therefore, in the gas turbine stator blade described in Patent Document 1, the effect of reducing cooling air is limited.

[0010] In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a gas turbine stator blade and a gas turbine capable of reducing the amount of cooling air for cooling the gas turbine stator blade.

[0011] Means for solving technical problems

[0012] In order to achieve the above-mentioned object, a gas turbine stator blade according to at least one embodiment of the present invention includes:

[0013] The blade body includes a negative pressure surface forming wall forming a negative pressure surface, and a pressure surface forming wall forming a pressure surface and forming a cavity in the blade between the negative pressure surface forming wall and the pressure surface forming wall;

[0014] A leading edge partition wall is formed integrally with the blade body, extends from the inner surface of the negative pressure surface forming wall to the inner surface of the pressure surface forming wall, and divides the inner cavity of the blade into a leading edge side cavity and a trailing edge side cavity;

[0015] A negative pressure surface side bulkhead is formed integrally with the blade body, extends from the inner surface of the blade body to the leading edge bulkhead in the leading edge side cavity, and divides the leading edge side cavity into a negative pressure surface side cavity and a pressure surface side cavity, and is formed with a negative pressure surface side impact cooling hole for cooling the negative pressure surface forming wall; and

[0016] a tubular pressure surface side insert, which is inserted into the pressure surface side cavity in such a manner that a first gap is provided between the pressure surface forming wall and a second gap is provided between the negative pressure surface side partition wall, and is formed with a pressure surface side impact cooling hole for cooling the pressure surface forming wall,

[0017] The gas turbine stator blade is configured such that at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole of the pressure surface side insert cools the negative pressure surface forming wall through the first gap, the second gap, and the negative pressure surface side impact cooling hole.

[0018] In order to achieve the above-mentioned object, a gas turbine according to at least one embodiment of the present invention includes:

[0019] The above-mentioned gas turbine stator blades;

[0020] turbine rotor; and

[0021] A casing accommodates the turbine rotor.

[0022] Effects of the Invention

[0023] According to at least one embodiment of the present invention, there are provided a gas turbine stator blade and a gas turbine capable of reducing the amount of cooling air used to cool the gas turbine stator blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a diagram showing a schematic configuration of a gas turbine 2 according to an embodiment.

[0025] Figure 2 This is a diagram showing an example of a cross section of a center portion in the blade height direction (a cross section orthogonal to the blade height direction) in a second-stage turbine stator blade 12A of the turbine 8 .

[0026] Figure 3 Yes Figure 2 The vicinity of the leading edge 30 in the cross section shown is shown in an enlarged view.

[0027] Figure 4 It is indicated by arrows Figure 2 Diagram of the flow of cooling air in the cross section shown.

[0028] Figure 5 This is a diagram showing another example of a cross section of a center portion in the blade height direction (a cross section orthogonal to the blade height direction) of a second-stage turbine stator blade 12A of the turbine 8 . DETAILED DESCRIPTION

[0029] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described or illustrated in the embodiments are not intended to limit the scope of the invention, but are merely illustrative examples.

[0030] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configuration not only indicate such configuration in a strict sense, but also indicate a state of relative displacement with a tolerance or an angle or distance that can achieve the same degree of functionality.

[0031] For example, expressions such as “same”, “equal” and “homogeneous” that indicate that things are in the same state not only indicate the same state in a strict sense, but also indicate a state in which there is a tolerance or a difference in the degree to which the same function can be obtained.

[0032] For example, expressions indicating shapes such as a quadrilateral or a cylinder not only indicate shapes such as a quadrilateral or a cylinder in a strict geometric sense, but also indicate shapes including concave-convex portions or chamfered portions as long as the same effect can be obtained.

[0033] On the other hand, the expression “having”, “set”, “equipped with”, “including” or “having” a constituent element is not an exclusive expression that excludes the existence of other constituent elements.

[0034] Figure 1This is a diagram showing a schematic configuration of a gas turbine 2 according to an embodiment.

[0035] like Figure 1 As shown, the gas turbine 2 includes a compressor 4 , a combustor 6 for mixing compressed air generated by the compressor 4 with fuel and burning the mixture, and a turbine 8 for obtaining power from the combustion gas generated by the combustor 6 .

[0036] like Figure 1 As shown, the turbine 8 includes: a rotor 9 (turbine rotor); a turbine casing 10 that accommodates the rotor 9; a plurality of turbine stationary blades 12 (gas turbine stationary blades) fixed to the inner surface of the turbine casing 10; and a plurality of turbine moving blades 16 implanted in the rotor 9 in an axially alternating arrangement relative to the turbine stationary blades 12.

[0037] Figure 2 The diagram is an example of a cross section of a center portion in the blade height direction (a cross section orthogonal to the blade height direction) of a turbine stator blade 12A of the second stage of the turbine 8, for example.

[0038] like Figure 2 As shown, the turbine stationary blade 12A includes a blade body 20 , a leading edge partition wall 22 , a suction surface side partition wall 24 , and a pressure surface side insert 26 .

[0039] The blade body 20 includes: a leading edge 30; a trailing edge 32; a negative pressure surface forming wall 36, which forms a negative pressure surface 34 connecting the leading edge 30 and the trailing edge 32; and a pressure surface forming wall 42, which forms a pressure surface 38 connecting the leading edge 30 and the trailing edge 32 and forms an inner blade cavity 40 between the negative pressure surface forming wall 36. The negative pressure surface forming wall 36 and the pressure surface forming wall 42 can each have a curved plate shape with a substantially constant thickness. The inner blade cavity 40 is formed on the inner side of the blade body 20 from one end to the other end of the blade body 20 along the blade height direction. In addition, in this specification, the "blade height direction" refers to the blade height direction of the turbine stator blade 12A, that is, it represents the blade height direction of the blade body 20.

[0040] The leading edge bulkhead 22 is provided in the blade inner cavity 40 and is formed integrally with the blade body 20 by casting. The leading edge bulkhead 22 is configured to extend from the inner surface 44 of the negative pressure surface forming wall 36 to the inner surface 45 of the pressure surface forming wall 42, and divides the blade inner cavity 40 into a leading edge side cavity 46 and a trailing edge side cavity 48. The leading edge bulkhead 22 may have a plate shape with a substantially constant thickness.

[0041] The negative pressure surface side bulkhead 24 is provided in the leading edge side cavity 46 and is formed integrally with the blade body 20 by casting. The negative pressure surface side bulkhead 24 is configured to extend from the inner surface of the blade body 20 (in the illustrated example, the inner surface 44 of the negative pressure surface forming wall 36) to the leading edge bulkhead 22 in the leading edge side cavity 46, and divide the leading edge side cavity 46 into a negative pressure surface side cavity 50 and a pressure surface side cavity 52. ​​A plurality of negative pressure surface side impact cooling holes 54 for impact cooling the negative pressure surface forming wall 36 are formed on the negative pressure surface side bulkhead 24. In the leading edge side cavity 46, only the negative pressure surface side bulkhead 24 is provided as a bulkhead formed by casting, and no other bulkhead formed by casting is provided. The negative pressure surface side bulkhead 24 may have a curved plate shape with a substantially constant thickness.

[0042] In the example shown in the figure, the negative pressure surface side partition wall 24 is bent into an S-shape in a cross section orthogonal to the blade height direction, and includes: a first bent portion 24a, which is bent in a manner extending along the negative pressure surface forming wall 36 and convex toward the negative pressure surface 34 side; and a second bent portion 24b, which is bent in a manner convex toward the pressure surface 38 side. One end of the first bent portion 24a is connected to a position on the negative pressure surface forming wall 36 side of the leading edge partition wall 22, and the other end of the first bent portion 24a is connected to one end of the second bent portion 24b. The other end of the second bent portion 24b is connected to a position near the leading edge 30 in the negative pressure surface forming wall 36.

[0043] The pressure surface side insert 26 is formed of sheet metal into a tubular shape so as to extend from one end to the other end of the blade body 20 along the blade height direction, and is inserted into the pressure surface side cavity 52. ​​The internal space 28 of the pressure surface side insert 26 is aligned with the internal space 28 of the turbine housing 10 (refer to FIG. Figure 1 ) is connected to an outer cavity (not shown) formed between the turbine stator blades 12A, and the compressed air supplied from the compressor 4 to the outer cavity is supplied from the outer cavity to the internal space 28 of the pressure surface side insert 26 as cooling air.

[0044] The pressure surface side insert 26 has gaps that serve as passages for cooling air between the wall surfaces that face the outer peripheral surface 27 of the pressure surface side insert 26. In the example shown in the figure, a gap 60a that serves as an air passage is provided between the pressure surface side insert 26 and the pressure surface forming wall 42, a gap 60b is provided between the pressure surface side insert 26 and the portion of the negative pressure surface forming wall 36 that faces the pressure surface side cavity 52, a gap 60c is provided between the pressure surface side insert 26 and the negative pressure surface side partition wall 24, and a gap 60d is provided between the pressure surface side insert 26 and the leading edge partition wall 22.

[0045] A plurality of pressure surface side impingement cooling holes 64 for impingement cooling the inner surface 45 of the pressure surface forming wall 42 are formed in the pressure surface side insert 26. The plurality of pressure surface side impingement cooling holes 64 are formed as through holes penetrating the wall surface of the pressure surface side insert 26 in a portion 26a of the pressure surface side insert 26 that is opposed to the pressure surface forming wall 42, and connect the internal space 28 of the pressure surface side insert 26 and the gap 60a.

[0046] In the example shown in the figure, a plurality of impingement cooling holes 65 for impingement cooling the inner surface 44 facing the pressure surface side cavity 52 in the negative pressure surface forming wall 36 are formed in the pressure surface side insert 26. The impingement cooling holes 65 arranged in the blade height direction are formed as through holes penetrating the wall surface of the pressure surface side insert 26 in a portion 26b of the pressure surface side insert 26 facing the negative pressure surface forming wall 36 (a portion of the negative pressure surface forming wall 36 facing the pressure surface side cavity 52). Impingement cooling holes are not formed in a portion 26c of the pressure surface side insert 26 facing the negative pressure surface side bulkhead 24 and a portion 26d of the pressure surface side insert 26 facing the leading edge bulkhead 22.

[0047] In the example shown in the figure, on a cross section orthogonal to the blade height direction, a portion 26c of the pressure side insert 26 that is opposite to the negative pressure side partition wall 24 is formed into an S shape along the negative pressure side partition wall 24, including: a third bent portion 26c1, which is bent in a manner extending along the first bent portion 24a of the negative pressure side partition wall 24 and convex toward the negative pressure surface 34 side; and a fourth bent portion 26c2, which is bent in a manner extending along the second bent portion 24b of the negative pressure side partition wall 24 and convex toward the pressure surface 38 side.

[0048] In the example shown in the figure, only the pressure-side insert 26 is provided as a tubular insert in the pressure-side cavity 52, and no tubular insert is provided in the pressure-side cavity 52 except the pressure-side insert 26. Furthermore, no tubular insert is provided in the negative-pressure-side cavity 50.

[0049] The pressure surface forming wall 42 does not have a film cooling hole that connects the pressure surface side cavity 52 with the outside of the blade body 20, but the negative pressure surface forming wall 36 has a plurality of film cooling holes 58 that connect the negative pressure surface side cavity 50 with the outside of the blade body 20. In the example shown in the figure, a plurality of film cooling holes 58 are arranged in the blade height direction at a position close to the leading edge partition wall 22 in the negative pressure surface forming wall 36. The film cooling holes 58 extend in a direction inclined to the direction orthogonal to the negative pressure surface 34 at the position of the outlet of the film cooling hole 58 so as to face the downstream side in the flow direction of the combustion gas along the negative pressure surface 34 as they approach the negative pressure surface 34.

[0050] Furthermore, in the example shown in the figure, a plurality of film cooling holes 59 are formed in the connection portion 25 connecting the negative pressure surface forming wall 36 and the negative pressure surface side partition wall 24, which are arranged along the blade height direction and communicate the pressure surface side cavity 52 with the outside of the blade body 20. The plurality of film cooling holes 59 are provided to cool the negative pressure surface forming wall 36 at the connection portion 25 where it is difficult to obtain a cooling effect based on impingement cooling, and are arranged along the blade height direction. The film cooling holes 59 each extend in a direction inclined in a direction perpendicular to the negative pressure surface 34 relative to the position of the outlet of the film cooling hole 59 so as to face the downstream side in the flow direction of the combustion gas along the negative pressure surface 34 as they approach the negative pressure surface 34.

[0051] Figure 3 Yes Figure 2 The vicinity of the leading edge 30 in the cross section shown is shown in an enlarged view.

[0052] like Figure 3 As shown, on a cross section orthogonal to the blade height direction, the blade surface 37 of the blade body 20 (the surface formed by the outer surface of the blade body 20, i.e., the negative pressure surface 34 and the pressure surface 38) includes: an arc 70 passing through the leading edge 30 and having a constant radius of curvature; and a curved portion 72 connected to the arc 70 on the negative pressure surface 34 side of the blade body 20 and having a radius of curvature greater than the arc 70. Here, if the position where the negative pressure surface side partition 24 is connected to the inner surface of the negative pressure surface forming wall 36 is set to P1, the position of the boundary between the arc 70 and the curved portion 72 is set to P2, the distance between the leading edge 30 and the position P1 is set to A1, and the distance between the leading edge 30 and the position P2 is set to A2, then A1>A2 is satisfied. In the example shown in the figure, the position P1 is located outside the circle Cl including the arc 70. In the example shown in the figure, position P1 more specifically indicates the center of the wall thickness of the suction surface side partition wall 24 at the position where the inner surface 44 of the suction surface forming wall 36 connects to the suction surface side partition wall 24 on the cross section perpendicular to the blade height direction.

[0053] like Figure 3As shown, in a cross section orthogonal to the blade height direction, if the position of the back side of the leading edge 30 corresponding to the leading edge 30 in the inner surface 39 of the blade body 20 (the surface formed by the inner surface 44 of the negative pressure surface forming wall 36 and the inner surface 45 of the pressure surface forming wall 42) is set to P3, the inner surface 39 of the blade body 20 includes: an arc 74 passing through the position P3 and having a constant radius of curvature; and a curved portion 76 connected to the arc 74 on the negative pressure surface 34 side of the blade body 20 and having a radius of curvature greater than the arc 74. Here, if the position of the boundary between the arc 74 and the curved portion 76 is set to P4, the distance between the position P1 and the position P3 is set to A3, and the distance between the position P3 and the position P4 is set to A4, then A3>A4 is satisfied. In the example shown in the figure, the position P1 is located outside the circle C2 including the arc 74.

[0054] Below, use Figure 4 The flow of cooling air in the turbine vane 12A will be described. Figure 4 It is indicated by arrows Figure 2 A cross-sectional view of the flow of cooling air in the cross section shown.

[0055] like Figure 4 As shown, cooling air supplied from an outer cavity (not shown) to the internal space 28 of the pressure surface side insert 26 is sprayed onto the inner surface 45 of the pressure surface forming wall 42 through a plurality of impingement cooling holes 64 formed in the pressure surface side insert 26, thereby impingement cooling the inner surface 45 of the pressure surface forming wall 42.

[0056] A portion of the cooling air that has passed through the plurality of impingement cooling holes 64 and has been impingement cooled by the pressure surface forming wall 42 sequentially passes through the gap 60a between the pressure surface side insert 26 and the pressure surface forming wall 42, the gap 60b between the pressure surface side insert 26 and the negative pressure surface forming wall 36, and the gap 60c between the pressure surface side insert 26 and the negative pressure surface side partition wall 24, and is supplied to the plurality of impingement cooling holes 54 of the negative pressure surface side partition wall 24. That is, the gap 60a, the gap 60b, and the gap 60c constitute a passage for the cooling air from the impingement cooling hole 64 to the impingement cooling hole 54.

[0057] Another part of the cooling air that has passed through the plurality of impingement cooling holes 64 and impingement-cooled the inner surface 45 of the pressure surface forming wall 42 sequentially passes through the gap 60a between the pressure surface side insert 26 and the pressure surface forming wall 42, the gap 60d between the pressure surface side insert 26 and the leading edge bulkhead 22, and the gap 60c between the pressure surface side insert 26 and the negative pressure surface bulkhead 24, and is supplied to the plurality of impingement cooling holes 54 of the negative pressure surface bulkhead 24. That is, the gap 60a, the gap 60d, and the gap 60c constitute a passage for the cooling air from the impingement cooling hole 64 to the impingement cooling hole 54.

[0058] The cooling air supplied from the gap 60c to the plurality of impingement cooling holes 54 is sequentially blown to the inner surface 44 of the negative pressure surface forming wall 36 through the plurality of impingement cooling holes 54 and the negative pressure surface side cavity 50, and impingement cools the inner surface 44 of the negative pressure surface forming wall 36. The cooling air that has impingement-cooled the negative pressure surface forming wall 36 through the plurality of impingement cooling holes 54 is discharged to the outside of the blade body 20 through the plurality of film cooling holes 58 formed in the negative pressure surface forming wall 36, and film cooling of the negative pressure surface 34 is performed on the downstream side of the film cooling holes 58 in the flow direction of the combustion gas.

[0059] Next, the effects exerted by the turbine vane 12A will be described.

[0060] In the turbine stator blade 12A, at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole 64 of the pressure surface side insert 26 sequentially passes through the gap 60a, the gap 60b, the gap 60c, and the negative pressure surface side impact cooling hole 54 to impact and cool the inner surface 44 of the negative pressure surface forming wall 36, and at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole 64 of the pressure surface side insert 26 sequentially passes through the gap 60a, the gap 60d, the gap 60c, and the negative pressure surface side impact cooling hole 54 to impact and cool the inner surface 44 of the negative pressure surface forming wall 36. In this way, the cooling air that has passed through the pressure surface side impact cooling hole 64 of the pressure surface side insert 26 impacts and cools the inner surface 45 of the pressure surface forming wall 42, and then further passes through the negative pressure surface side impact cooling hole 54 of the negative pressure surface side partition wall 24 to impact and cool the inner surface 44 of the negative pressure surface forming wall 36.

[0061] In this way, the cooling air used for the impact cooling of the inner surface 45 of the pressure surface forming wall 42 can be repeatedly used for the impact cooling of the inner surface 44 of the negative pressure surface side partition wall, so the amount of cooling air used to cool the turbine stator blade 12A (the amount of cooling air) can be reduced. In addition, since the negative pressure surface side partition wall 24 and the blade body 20 are formed integrally by casting, the problem of cooling air leaking from the gap between the rib-shaped wall and the insert on the negative pressure surface side in the structure described in Patent Document 1 does not occur, so the impact cooling of the inner surface 44 of the negative pressure surface forming wall 36 can be effectively performed with a small amount of cooling air. As a result, the amount of cooling air used to cool the turbine stator blade 12A (the amount of cooling air) can be effectively reduced.

[0062] Furthermore, in the turbine stator blade 12A, the film cooling holes that communicate the pressure surface side cavity 52 with the outside of the blade body 20 are not formed in the pressure surface forming wall 42, and the film cooling holes 58 that communicate the negative pressure surface side cavity 50 with the outside of the blade body 20 are formed in the negative pressure surface 34. Thus, the cooling air used for the impingement cooling of the inner surface 45 of the pressure surface forming wall 42 can be effectively repeatedly used for the impingement cooling of the inner surface 44 of the negative pressure surface forming wall 36. Furthermore, even if the pressure of the cooling air is reduced by performing two-stage impingement cooling including impingement cooling of the inner surface 45 of the pressure surface forming wall 42 and impingement cooling of the inner surface 44 of the negative pressure surface forming wall 36, the pressure of the combustion gas around the blade body 20 is lower on the negative pressure surface side than on the pressure surface side, so that the pressure of the cooling air supplied to the pressure surface side insert 26 is not excessively increased, and the cooling air is discharged to the outside of the blade body 20 from the film cooling holes 58 formed in the negative pressure surface forming wall 36, so that the film cooling of the negative pressure surface 34 can be performed. As a result, the pressure surface forming wall 42 and the negative pressure surface forming wall 36 can be effectively cooled with a small amount of cooling air.

[0063] Furthermore, normally, the pressure of the combustion gas tends to be high at the leading edge 30 of the blade body 20 and its vicinity. However, in the turbine stator blade 12A, since the negative pressure side bulkhead 24 extends from the inner surface 44 of the negative pressure surface forming wall 36 to the leading edge bulkhead 22, the pressure of the space on the back side of the leading edge 30 in the blade body 20 (the pressure near the position P3) can be set to the relatively high pressure of the cooling air before the second stage of impingement cooling is performed. Therefore, compared with the case where the negative pressure side bulkhead 24 extends from the inner surface 45 of the pressure surface forming wall 42 to the leading edge bulkhead 22 (for example, refer to Figure 5 ) can increase the pressure on the back side of the leading edge 30 of the blade body 20. Therefore, even if a hole is opened at the leading edge 30 of the blade body 20 due to heat damage or the like, the high pressure of the cooling air before the second stage of impingement cooling can suppress the high-temperature combustion gas from flowing into the interior of the blade body 20, thereby suppressing damage to the interior of the turbine stator blade 12A.

[0064] And, when using Figure 3 In the structure being described, since the pressure of the combustion gas is particularly likely to become high in the portion of the above-mentioned arc 70 passing through the leading edge 30 of the blade body 20, by satisfying A1>A2 (and / or satisfying A3>A4) as described above, even if a hole is opened at the position of the above-mentioned arc 70 of the blade body 20 due to heat damage, the high pressure of the cooling air before the second stage impact cooling can suppress the high-temperature combustion gas from flowing into the interior of the blade body 20, thereby suppressing damage to the interior of the turbine stator blade 12A.

[0065] The present invention is not limited to the above-described embodiments, and includes modified embodiments of the above-described embodiments or embodiments in which these embodiments are appropriately combined.

[0066] In several embodiments, for example, Figure 5 As shown, one end of the suction side partition wall 24 may be connected to the inner surface 45 of the pressure surface forming wall 42. In this case, the suction side partition wall 24 may be composed of only the curved portion 24c convex toward the suction side in the cross section perpendicular to the blade height direction.

[0067] The contents described in the above-mentioned embodiments can be understood, for example, as follows.

[0068] (1) A gas turbine stationary blade according to at least one embodiment of the present invention (for example, the above-mentioned turbine stationary blade 12A) includes:

[0069] A blade body (e.g., the blade body 20 described above), including a negative pressure surface forming wall (e.g., the negative pressure surface forming wall 36 described above) that forms a negative pressure surface (e.g., the negative pressure surface 34 described above), and a pressure surface forming wall (e.g., the pressure surface 38 described above) that forms a blade inner cavity (e.g., the blade inner cavity 40 described above) between the negative pressure surface forming wall and the pressure surface forming wall;

[0070] A leading edge bulkhead (e.g., the leading edge bulkhead 22) is formed integrally with the blade body, extends from the inner surface of the negative pressure surface forming wall (e.g., the inner surface 44) to the inner surface of the pressure surface forming wall (e.g., the inner surface 45), and divides the blade inner cavity into a leading edge side cavity (e.g., the leading edge side cavity 46) and a trailing edge side cavity (e.g., the trailing edge side cavity 48);

[0071] A negative pressure surface side bulkhead (e.g., the negative pressure surface side bulkhead 24 described above) is formed integrally with the blade body, extends from the inner surface of the blade body to the leading edge bulkhead in the leading edge side cavity, and divides the leading edge side cavity into a negative pressure surface side cavity (e.g., the negative pressure surface side cavity 50 described above) and a pressure surface side cavity (e.g., the pressure surface side cavity 52 described above), and is formed with a negative pressure surface side impact cooling hole (e.g., the negative pressure surface side impact cooling hole 54 described above) for cooling the negative pressure surface forming wall; and

[0072] A tubular pressure surface side insert (e.g., the pressure surface side insert 26) is inserted into the pressure surface side cavity in such a manner that a first gap (e.g., the gap 60a) is provided between the pressure surface forming wall and a second gap (e.g., the gap 60c) is provided between the negative pressure surface side partition wall, and a pressure surface side impact cooling hole (e.g., the pressure surface side impact cooling hole 64) for cooling the pressure surface forming wall is formed.

[0073] The gas turbine stator blade is configured such that at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole of the pressure surface side insert cools the negative pressure surface forming wall through the first gap, the second gap, and the negative pressure surface side impact cooling hole.

[0074] According to the gas turbine stator blade described in (1) above, the cooling air used for the impingement cooling of the inner surface of the pressure surface forming wall can be repeatedly used for the impingement cooling of the inner surface of the negative pressure surface side partition wall, thereby reducing the amount of cooling air used to cool the gas turbine stator blade (the amount of cooling air). Furthermore, since the negative pressure surface side partition wall and the blade body are formed integrally, the problem of cooling air leaking from the gap between the rib-shaped wall and the insert on the negative pressure surface side in the structure described in Patent Document 1 does not occur, so the inner surface of the negative pressure surface forming wall can be effectively impinged cooled with a small amount of cooling air. As a result, the amount of cooling air used to cool the gas turbine stator blade (the amount of cooling air) can be effectively reduced.

[0075] (2) In some embodiments, in the gas turbine stator blade described in (1) above,

[0076] No film cooling hole is formed on the pressure surface forming wall to connect the pressure surface side cavity with the outside of the blade body, and a film cooling hole (for example, the above-mentioned film cooling hole 58) is formed on the negative pressure surface forming wall to connect the negative pressure surface side cavity with the outside of the blade body.

[0077] According to the gas turbine stator blade described in (2) above, the cooling air used for the impingement cooling of the inner surface of the pressure surface forming wall can be effectively and repeatedly used for the impingement cooling of the inner surface of the negative pressure surface forming wall. Furthermore, even if the pressure of the cooling air decreases due to the two-stage impingement cooling including the impingement cooling of the inner surface of the pressure surface forming wall and the impingement cooling of the inner surface of the negative pressure surface forming wall, since the pressure of the combustion gas around the blade body is lower on the negative pressure side than on the pressure side, the pressure of the cooling air supplied to the pressure surface side insert will not be excessively increased, and the cooling air can be discharged from the film cooling holes formed in the negative pressure surface forming wall to the outside of the blade body, thereby enabling film cooling of the negative pressure surface. As a result, the pressure surface forming wall and the negative pressure surface forming wall can be effectively cooled with a small amount of cooling air.

[0078] (3) In some embodiments, in the gas turbine stator blade described in (1) or (2),

[0079] The blade body and the suction surface side partition wall are integrally formed by casting, and the pressure surface side insert is formed of sheet metal.

[0080] According to the gas turbine stator blade described in (3), since the blade body and the negative pressure side partition wall are formed integrally, there is no problem of cooling air leaking from the gap between the rib-shaped wall and the insert on the negative pressure side in the structure described in Patent Document 1, so that the inner surface of the negative pressure surface forming wall can be effectively impinged and cooled with a small amount of cooling air. In addition, by forming the pressure side insert with sheet metal, the gas turbine stator blade described in (1) or (2) can be easily manufactured.

[0081] (4) In some embodiments, in the gas turbine stator blade described in any one of (1) to (3) above,

[0082] The suction surface side partition wall extends from the inner surface of the suction surface forming wall to the leading edge portion partition wall.

[0083] The pressure of the combustion gas tends to be high at the leading edge of the blade body and its vicinity, but in the gas turbine stator blade described in (4) above (for example, see Figure 4 ), the pressure of the space on the back side of the leading edge in the blade body can be set to the pressure of the cooling air before the second stage of impact cooling, so that the negative pressure side partition extends from the inner surface of the pressure surface forming wall to the leading edge partition (for example, refer to Figure 5) can increase the pressure on the back side of the leading edge of the blade body. Therefore, even if a hole is formed at the leading edge of the blade body due to thermal damage, the high pressure of the cooling air before the second stage of impingement cooling can suppress the high temperature combustion gas from flowing into the interior of the blade body, thereby suppressing damage to the interior of the gas turbine stator blade.

[0084] (5) In some embodiments, in the gas turbine stator blade described in (4) above,

[0085] On a cross section orthogonal to the blade height direction, the blade surface of the blade body (e.g., the blade surface 37) includes: an arc (e.g., the arc 70) passing through the leading edge (e.g., the leading edge 30) of the blade body and having a constant radius of curvature; and a curved portion (e.g., the curved portion 72) connected to the arc on the negative pressure surface side of the blade body and having a radius of curvature greater than the arc,

[0086] On a cross section perpendicular to the blade height direction, if the position where the negative pressure surface side partition wall is connected to the inner surface of the negative pressure surface forming wall is set to P1, the position of the boundary between the arc and the curved portion is set to P2, the distance between the leading edge and the position P1 is set to A1, and the distance between the leading edge and the position P2 is set to A2, then A1>A2 is satisfied.

[0087] Since the pressure of the combustion gas is particularly likely to become high in the portion of the above-mentioned arc passing through the leading edge of the blade body, by satisfying A1>A2 as described in (5) above, even if a hole is opened at the position of the above-mentioned arc of the blade body due to heat damage, the high pressure of the cooling air before the second-stage impact cooling can suppress the high-temperature combustion gas from flowing into the interior of the blade body, thereby suppressing damage to the interior of the gas turbine stationary blade.

[0088] (6) In some embodiments, in the gas turbine stator blade described in (4) or (5),

[0089] On a cross section orthogonal to the blade height direction, if the position on the back side of the leading edge corresponding to the leading edge of the blade body (for example, the above-mentioned leading edge) in the inner surface of the blade body is set to P3, the inner surface of the blade body includes: an arc (for example, the above-mentioned arc 74), which passes through the position P3 and has a constant radius of curvature; and a curved portion (for example, the above-mentioned curved portion 76), which is connected to the arc on the wall side of the negative pressure surface of the blade body and has a radius of curvature greater than the arc,

[0090] On a cross section perpendicular to the blade height direction, if the position of the boundary between the arc and the curved portion is set to P4, the distance between the position P1 and the position P3 is set to A3, and the distance between the position P3 and the position P4 is set to A4, then A3>A4 is satisfied.

[0091] Since the pressure of the combustion gas is particularly likely to become high in the portion of the above-mentioned arc passing through the leading edge of the blade body, by satisfying A3>A4 as described in (6) above, even if a hole is opened at the position of the above-mentioned arc of the blade body due to heat damage, the high pressure of the cooling air before the second stage impact cooling can suppress the high-temperature combustion gas from flowing into the interior of the blade body, thereby suppressing damage to the interior of the gas turbine stationary blade.

[0092] (7) In some embodiments, in the gas turbine stator blade described in any one of (4) to (6),

[0093] On a cross section perpendicular to the blade height direction, the negative pressure surface side partition wall is bent into an S shape, including: a first bent portion (for example, the first bent portion 24a mentioned above), which is bent in a manner extending along the negative pressure surface forming wall and convex toward the negative pressure surface side; and a second bent portion (for example, the second bent portion 24b mentioned above), which is bent in a manner convex toward the pressure surface side, the first bent portion is connected to a position on the negative pressure surface forming wall side in the leading edge partition wall, and the second bent portion is connected to an inner surface of the negative pressure surface forming wall.

[0094] According to the gas turbine stator blade described in (7) above, the effect exerted by the gas turbine stator blade described in any one of (4) to (6) above can be obtained, and the distance between the negative pressure surface forming wall and the negative pressure surface side partition wall can be kept constant over a wide range, thereby effectively impact cooling the inner surface of the negative pressure surface forming wall.

[0095] (8) In some embodiments, in the gas turbine stator blade described in (7) above,

[0096] On a cross section orthogonal to the blade height direction, a portion of the pressure side insert that is opposite to the negative pressure side partition wall (for example, the above-mentioned portion 26c) is formed into an S-shape along the negative pressure side partition wall, including: a third bend portion (for example, the above-mentioned third bend portion 26c1), which is bent in a manner extending along the first bend portion of the negative pressure side partition wall and convex toward the negative pressure side; and a fourth bend portion (for example, the above-mentioned fourth bend portion 26c2), which is bent in a manner extending along the second bend portion of the negative pressure side partition wall and convex toward the pressure side.

[0097] According to the gas turbine stator blade described in (8) above, by setting the portion of the pressure side insert opposite to the negative pressure side partition wall into an S shape along the negative pressure side partition wall, the increase in pressure loss in the pressure side cavity can be suppressed and the effect exerted by the gas turbine stator blade described in (7) above can be obtained.

[0098] (9) In some embodiments, in the gas turbine stator blade described in any one of (1) to (8),

[0099] A third gap (for example, the gap 60d) is provided between the pressure surface side insert and the front edge partition wall.

[0100] The gas turbine stator blade is configured such that at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole of the pressure surface side insert cools the negative pressure surface forming wall through the first gap, the third gap, the second gap, and the negative pressure surface side impact cooling hole.

[0101] According to the gas turbine stator blade described in (9) above, it is possible to suppress an increase in pressure loss in the cavity on the pressure surface side and obtain the effects exerted by the gas turbine stator blade described in any one of (1) to (8) above.

[0102] (10) In some embodiments, in the gas turbine stator blade described in any one of (1) to (9),

[0103] A film cooling hole that connects the pressure surface side cavity with the outside of the blade body is formed at a connection portion (for example, the connection portion 25 ) between the suction surface forming wall and the suction surface side partition wall.

[0104] According to the gas turbine stator blade described in (10) above, the connection portion, at which the cooling effect by impingement cooling is difficult to obtain, can be effectively cooled by air passing through the film cooling holes.

[0105] (11) A gas turbine according to at least one embodiment of the present invention includes:

[0106] The gas turbine stator blade according to any one of (1) to (10) above;

[0107] turbine rotor; and

[0108] A casing accommodates the turbine rotor.

[0109] According to the gas turbine described in (11) above, it is possible to reduce the amount of cooling air used for cooling the gas turbine stator blades.

[0110] Explanation of symbols

[0111] 2-gas turbine, 4-compressor, 6-combustor, 8-turbine, 9-rotor, 10-turbine housing, 12, 12A-turbine stator blades (gas turbine stator blades), 16-turbine moving blades, 20-blade body, 22-front edge bulkhead, 24-negative pressure side bulkhead, 24a-first curved portion, 24b-second curved portion, 24c-curved portion, 26-pressure side insert, 26a, 26b, 26c, 26d-part, 26c1-third curved portion, 26c2-fourth curved portion, 27-outer peripheral surface, 28-inner space, 30- Leading edge, 32-trailing edge, 34-negative pressure surface, 36-negative pressure surface forming wall, 37-blade surface, 38-pressure surface, 39, 44, 45-inner surface, 40-blade inner cavity, 42-pressure surface forming wall, 46-leading edge side cavity, 48-trailing edge side cavity, 50-negative pressure surface side cavity, 52-pressure surface side cavity, 54-negative pressure surface side impact cooling hole, 58, 59-film cooling hole, 64-pressure surface side impact cooling hole, 65-impact cooling hole, 60a, 60b, 60c, 60d-gap, 70, 74-arc, 72, 76-curved portion.

Claims

1. A gas turbine stator blade, comprising: The blade body includes a negative pressure surface forming wall forming a negative pressure surface, and a pressure surface forming wall forming a pressure surface and forming a cavity in the blade between the negative pressure surface forming wall and the pressure surface forming wall; A leading edge partition wall is formed integrally with the blade body, extends from the inner surface of the negative pressure surface forming wall to the inner surface of the pressure surface forming wall, and divides the inner cavity of the blade into a leading edge side cavity and a trailing edge side cavity; A negative pressure surface side bulkhead is formed integrally with the blade body, extends from the inner surface of the blade body to the leading edge bulkhead in the leading edge side cavity, and divides the leading edge side cavity into a negative pressure surface side cavity and a pressure surface side cavity, and is formed with a negative pressure surface side impact cooling hole for cooling the negative pressure surface forming wall; and a tubular pressure surface side insert, which is inserted into the pressure surface side cavity in such a manner that a first gap is provided between the pressure surface forming wall and a second gap is provided between the negative pressure surface side partition wall, and is formed with a pressure surface side impact cooling hole for cooling the pressure surface forming wall, The gas turbine stator blade is configured such that at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole of the pressure surface side insert cools the suction surface forming wall through the first gap, the second gap, and the suction surface side impact cooling hole.

2. The gas turbine stator blade according to claim 1, wherein: The pressure surface forming wall does not have a film cooling hole connecting the pressure surface side cavity with the outside of the blade body, and the negative pressure surface forming wall has a film cooling hole connecting the negative pressure surface side cavity with the outside of the blade body.

3. The gas turbine stator blade according to claim 1, wherein: The blade body and the suction surface side partition wall are integrally formed by casting, and the pressure surface side insert is formed of sheet metal.

4. The gas turbine stator blade according to claim 1, wherein: The suction surface side partition wall extends from the inner surface of the suction surface forming wall to the leading edge portion partition wall.

5. The gas turbine stator blade according to claim 4, wherein: On a cross section orthogonal to the blade height direction, the blade surface of the blade body includes: an arc passing through the leading edge of the blade body and having a constant curvature radius; and a curved portion connected to the arc on the negative pressure surface side of the blade body and having a curvature radius greater than the arc, On a cross section perpendicular to the blade height direction, if the position where the negative pressure surface side partition wall is connected to the inner surface of the negative pressure surface forming wall is set to P1, the position of the boundary between the arc and the curved portion is set to P2, the distance between the leading edge and the position P1 is set to A1, and the distance between the leading edge and the position P2 is set to A2, then A1>A2 is satisfied.

6. The gas turbine stator blade according to claim 4, wherein: On a cross section orthogonal to the blade height direction, if the position on the back side of the leading edge corresponding to the leading edge of the blade body in the inner surface of the blade body is set to P3, the inner surface of the blade body includes: an arc passing through the position P3 and having a constant curvature radius; and a curved portion connected to the arc on the negative pressure surface forming wall side of the blade body and having a curvature radius greater than the arc, On a cross section perpendicular to the blade height direction, if the position of the boundary between the arc and the curved portion is set to P4, the distance between the position P1 and the position P3 is set to A3, and the distance between the position P3 and the position P4 is set to A4, then A3>A4 is satisfied.

7. The gas turbine stator blade according to claim 4, wherein: On a cross section perpendicular to the blade height direction, the negative pressure surface side partition is bent into an S shape, including: a first bent portion, which is bent in a manner extending along the negative pressure surface forming wall and convex toward the negative pressure surface side; and a second bent portion, which is bent in a manner convex toward the pressure surface side, the first bent portion is connected to a position on the negative pressure surface forming wall side in the leading edge partition, and the second bent portion is connected to an inner surface of the negative pressure surface forming wall.

8. The gas turbine stator blade according to claim 7, wherein: On a cross section orthogonal to the blade height direction, a portion of the pressure side insert that is opposite to the negative pressure side partition wall is formed in an S shape along the negative pressure side partition wall, including: a third bent portion that is bent along the first bent portion of the negative pressure side partition wall and convexly extends toward the negative pressure side; and a fourth bent portion that is bent along the second bent portion of the negative pressure side partition wall and convexly extends toward the pressure side.

9. The gas turbine stator blade according to claim 1, wherein: A third gap is provided between the pressure surface side insert and the front edge partition wall. The gas turbine stator blade is configured such that at least a portion of the cooling air that has passed through the pressure surface side impact cooling hole of the pressure surface side insert cools the inner surface of the negative pressure surface forming wall through the first gap, the third gap, the second gap, and the negative pressure surface side impact cooling hole.

10. The gas turbine stator blade according to claim 1, wherein: A film cooling hole that connects the pressure surface side cavity with the outside of the blade body is formed at a connection portion between the suction surface forming wall and the suction surface side partition wall.

11. A gas turbine comprising: The gas turbine stator blade according to any one of claims 1 to 10; turbine rotor; and A casing accommodates the turbine rotor.

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