Gas turbine stator vane and gas turbine

Abstract

This gas turbine stator blade is provided with: a leading edge part partition that divides a cavity inside the blade into a leading edge side cavity and a trailing edge side cavity; a negative pressure surface side partition wall that is integrally formed with a blade body, divides the leading edge side cavity into a negative pressure surface side cavity and a pressure surface side cavity, and has a negative pressure surface side impingement cooling hole formed therein; and a tube-shaped pressure surface side insert that is inserted into the pressure surface side cavity so as to provide a first gap with respect to a pressure surface forming wall and provide a second gap with respect to the negative pressure surface side partition wall, and has a pressure surface side impingement cooling hole formed therein. At least a part of cooling air having passed through the pressure surface side impingement cooling hole is configured to cool the negative pressure surface forming wall via the first gap, the second gap, and the negative pressure surface side impingement cooling hole.

Description

[Technical Field]

[0001] The present disclosure relates to a gas turbine vane and a gas turbine. This application claims priority based on Japanese Patent Application No. 2022-106933, filed with the Japan Patent Office on July 1, 2022, the contents of which are incorporated herein by reference. [Background technology]

[0002] Patent Document 1 discloses a structure for reducing the amount of cooling air required to cool a gas turbine stator vane. The gas turbine stator vane includes a blade body having an intra-blade cavity formed between a suction surface wall and a pressure surface wall. A leading-edge partition wall extends from the inner surface of the suction surface wall to the inner surface of the pressure surface wall, dividing the intra-blade cavity into a leading-edge cavity and a trailing-edge cavity. A hollow insert is disposed on each of the pressure surface and suction surface sides of the leading-edge cavity. A portion of the cooling air blown from the impingement cooling holes in the insert disposed on the pressure surface side toward the inner surface of the pressure surface wall of the blade body flows along the inner surface of the blade body and is introduced into the insert disposed on the suction surface side. Then, the cooling air is blown out from the impingement cooling holes in the insert disposed on the suction surface side toward the inner surface of the suction surface wall, and is then discharged to the outside of the blade body through film cooling holes formed in the suction surface wall. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5022097 Summary of the Invention [Problem to be solved by the invention]

[0004] In the gas turbine vane described in Patent Document 1, in order to prevent a portion of the cooling air blown from the impingement 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 on the suction surface without flowing into the insert on the suction surface side, the leading edge side cavity is provided with a rib-like wall protruding from the inner surface of the blade body toward the insert on the suction surface side and a rib-like wall protruding from the leading edge bulkhead toward the insert on the suction surface side, on both sides of the insert on the suction surface side.

[0005] However, because the rib-like wall and the suction surface insert are formed of separate members, cooling air leaks from the gap between the rib-like wall and the suction surface insert, reducing the effectiveness of impingement cooling on the inner surface of the suction surface forming wall. For this reason, the gas turbine vane described in Patent Document 1 has only a limited effect in reducing the amount of cooling air.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure has an object to provide a gas turbine vane and a gas turbine that can reduce the amount of cooling air for cooling the gas turbine vane. [Means for solving the problem]

[0007] In order to achieve the above object, a gas turbine stator vane according to at least one embodiment of the present disclosure comprises: a blade body including a suction surface forming wall that forms a suction surface, and a pressure surface forming wall that forms a pressure surface and forms an intra-blade cavity between itself and the suction surface forming wall; a leading edge partition wall formed integrally with the blade body, extending from the inner surface of the suction surface forming wall to the inner surface of the pressure surface forming wall, and dividing the blade cavity into a leading edge side cavity and a trailing edge side cavity; a suction surface side bulkhead formed integrally with the blade body, extending from the inner surface of the blade body to the leading edge bulkhead in the leading edge side cavity to divide the leading edge side cavity into a suction surface side cavity and a pressure surface side cavity, and having suction surface side impingement cooling holes formed therein for cooling the suction surface forming wall; a tubular pressure surface side insert inserted into the pressure surface side cavity so as to provide a first gap between itself and the pressure surface forming wall and a second gap between itself and the suction surface side partition wall, the pressure surface side insert having pressure surface side impingement cooling holes formed therein for cooling the pressure surface forming wall; Equipped with At least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes of the pressure surface side insert is configured to pass through the first gap, the second gap, and the suction surface side impingement cooling holes to cool the suction surface forming wall.

[0008] In order to achieve the above object, a gas turbine according to at least one embodiment of the present disclosure comprises: The gas turbine stator blade; A turbine rotor; a casing that houses the turbine rotor; Equipped with. [Effects of the Invention]

[0009] According to at least one embodiment of the present disclosure, a gas turbine vane and a gas turbine are provided that can reduce the amount of cooling air used to cool the gas turbine vane. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a schematic configuration of a gas turbine 2 according to an embodiment. [Figure 2] 1 is a diagram showing an example of a cross section (cross section perpendicular to the blade height direction) of a central portion in the blade height direction of a second-stage turbine stator blade 12A of a turbine 8. FIG. [Figure 3] 3 is an enlarged view showing the vicinity of the leading edge 30 in the cross section shown in FIG. 2. FIG. [Figure 4] 3 is a diagram showing the flow of cooling air in the cross section shown in FIG. 2 by arrows. [Figure 5] 10 is a diagram showing another example of a cross section (cross section perpendicular to the blade height direction) of the center part in the blade height direction of the second stage turbine stator blade 12A of the turbine 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the invention. For example, expressions expressing relative or absolute arrangement such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" not only express such an arrangement exactly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions such as "identical," "equal," and "homogeneous" that indicate that something is in an equal state not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. For example, expressions representing shapes such as a square shape or a cylindrical shape not only represent shapes such as a square shape or a cylindrical shape in the strict geometric sense, but also represent shapes including uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. On the other hand, the expressions "comprise," "include," "have," "includes," or "have" of one element are not exclusive expressions that exclude the presence of other elements.

[0012] FIG. 1 is a diagram showing a schematic configuration of a gas turbine 2 according to one embodiment. As shown in FIG. 1, 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.

[0013] As shown in FIG. 1, the turbine 8 includes a rotor 9 (turbine rotor), a turbine casing 10 that houses the rotor 9, a plurality of turbine vanes 12 (gas turbine vanes) fixed to the inner surface of the turbine casing 10, and a plurality of turbine blades 16 that are implanted in the rotor 9 so as to be arranged alternately with respect to the turbine vanes 12 in the axial direction.

[0014] FIG. 2 is a diagram showing an example of a cross section (cross section perpendicular to the blade height direction) of the center part in the blade height direction of, for example, a second-stage turbine stator blade 12A of the turbine 8.

[0015] As shown in FIG. 2, the turbine vane 12A includes a vane body 20, a leading edge bulkhead 22, a suction side bulkhead 24, and a pressure side insert 26.

[0016] The blade body 20 includes a leading edge 30, a trailing edge 32, a suction surface forming wall 36 that forms a suction surface 34 connecting the leading edge 30 and the trailing edge 32, and a pressure surface forming wall 42 that forms a pressure surface 38 connecting the leading edge 30 and the trailing edge 32 and that forms an intra-blade cavity 40 between the suction surface forming wall 36 and the pressure surface forming wall 42. Each of the suction surface forming wall 36 and the pressure surface forming wall 42 may have a curved plate shape with a substantially constant thickness. The intra-blade cavity 40 is formed inside the blade body 20 along the blade height direction from one end to the other end of the blade body 20. Note that in this specification, the "blade height direction" means the blade height direction of the turbine stator vane 12A, i.e., the blade height direction of the blade body 20.

[0017] The leading-edge partition wall 22 is provided in the blade intra-cavity 40 and is formed integrally with the blade body 20 by casting. The leading-edge partition wall 22 extends from the inner surface 44 of the suction surface forming wall 36 to the inner surface 45 of the pressure surface forming wall 42 and is configured to divide the blade intra-cavity 40 into a leading-edge side cavity 46 and a trailing-edge side cavity 48. The leading-edge partition wall 22 may have a plate shape with a substantially constant thickness.

[0018] The suction surface side bulkhead 24 is provided in the leading edge side cavity 46 and is integrally formed with the blade body 20 by casting. The suction surface side bulkhead 24 extends from the inner surface of the blade body 20 (in the illustrated example, the inner surface 44 of the suction surface forming wall 36) to the leading edge partition 22 in the leading edge side cavity 46 and is configured to divide the leading edge side cavity 46 into a suction surface side cavity 50 and a pressure surface side cavity 52. ​​The suction surface side bulkhead 24 is formed with a plurality of suction surface side impingement cooling holes 54 for impingement cooling the suction surface forming wall 36. The leading edge side cavity 46 is provided with only the suction surface side bulkhead 24 as a bulkhead formed by casting, and no other bulkheads formed by casting are provided. The suction surface side bulkhead 24 may have a curved plate shape with a substantially constant thickness.

[0019] In the illustrated example, in a cross section perpendicular to the blade height direction, the suction surface side partition wall 24 is curved in an S-shape and includes a first curved portion 24a that extends along the suction surface forming wall 36 and curves convexly toward the suction surface 34, and a second curved portion 24b that curves convexly toward the pressure surface 38. One end of the first curved portion 24a is connected to a position on the leading edge partition wall 22 on the suction surface forming wall 36 side, and the other end of the first curved portion 24a is connected to one end of the second curved portion 24b. The other end of the second curved portion 24b is connected to a position on the suction surface forming wall 36 near the leading edge 30.

[0020] The pressure surface side insert 26 is formed from sheet metal into a tubular shape extending from one end to the other end of the blade body 20 in the blade height direction, and is inserted into the pressure surface side cavity 52. ​​An internal space 28 of the pressure surface side insert 26 communicates with an external cavity (not shown) formed between the turbine casing 10 (see FIG. 1) and the turbine stator blade 12A, and compressed air supplied from the compressor 4 to the external cavity is supplied from the external cavity to the internal space 28 of the pressure surface side insert 26 as cooling air.

[0021] A gap serving as a passage for cooling air is formed between the pressure surface side insert 26 and the wall surface facing the outer peripheral surface 27 of the pressure surface side insert 26. In the example shown, a gap 60a serving 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 a portion of the suction surface forming wall 36 facing the pressure surface side cavity 52, a gap 60c is provided between the pressure surface side insert 26 and the suction 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.

[0022] A plurality of pressure surface side impingement cooling holes 64 are formed in the pressure surface side insert 26 for impingement cooling the inner surface 45 of the pressure surface forming wall 42. The plurality of pressure surface side impingement cooling holes 64 are formed as through holes that penetrate the wall surface of the pressure surface side insert 26 in a portion 26a of the pressure surface side insert 26 that faces the pressure surface forming wall 42, and communicate the internal space 28 of the pressure surface side insert 26 with the gap 60a.

[0023] In the illustrated example, the pressure surface side insert 26 is formed with a plurality of impingement cooling holes 65 for impingement cooling the inner surface 44 of the suction surface forming wall 36 that faces the pressure surface side cavity 52. ​​The plurality of impingement cooling holes 65 arranged along the blade height direction are formed as through holes that penetrate the wall surface of the pressure surface side insert 26 in a portion 26b of the pressure surface side insert 26 that faces the suction surface forming wall 36 (a portion of the suction surface forming wall 36 that faces the pressure surface side cavity 52). No impingement cooling holes are formed in a portion 26c of the pressure surface side insert 26 that faces the suction surface side partition wall 24 and a portion 26d of the pressure surface side insert 26 that faces the leading edge partition wall 22.

[0024] In the illustrated example, in a cross section perpendicular to the blade height direction, the portion 26c of the pressure surface side insert 26 facing the suction surface side partition wall 24 is formed in an S-shape along the suction surface side partition wall 24, and includes a third curved portion 26c1 extending along the first curved portion 24a of the suction surface side partition wall 24 and curved convexly toward the suction surface 34 side, and a fourth curved portion 26c2 extending along the second curved portion 24b of the suction surface side partition wall 24 and curved convexly toward the pressure surface 38 side.

[0025] In the illustrated example, the pressure surface side cavity 52 is provided with only the pressure surface side insert 26 as a tubular insert, and no other tubular inserts are provided in the pressure surface side cavity 52 other than the pressure surface side insert 26. In addition, no tubular inserts are provided in the suction surface side cavity 50.

[0026] No film cooling hole connecting the pressure surface cavity 52 to the outside of the blade body 20 is formed in the pressure surface forming wall 42, but a plurality of film cooling holes 58 connecting the suction surface cavity 50 to the outside of the blade body 20 is formed in the suction surface forming wall 36. In the illustrated example, the plurality of film cooling holes 58 are arranged along the blade height direction at positions in the suction surface forming wall 36 near the leading edge partition 22. Each of the film cooling holes 58 extends in a direction inclined with respect to the direction perpendicular to the suction surface 34 at the exit position of the film cooling hole 58, so as to move toward the downstream side in the flow direction of the combustion gas along the suction surface 34 as it approaches the suction surface 34.

[0027] In the illustrated example, a plurality of film cooling holes 59 are formed in the connection portion 25 where the suction surface forming wall 36 and the suction surface side bulkhead 24 are connected, the film cooling holes 59 being arranged along the blade height direction and communicating between the pressure surface side cavity 52 and the outside of the blade body 20. The film cooling holes 59 are provided to cool the suction surface forming wall 36 at the connection portion 25 where the cooling effect of impingement cooling is difficult to obtain, and are arranged along the blade height direction. Each of the film cooling holes 59 extends in a direction inclined with respect to the direction perpendicular to the suction surface 34 at the outlet of the film cooling hole 59, so as to move toward the downstream side in the flow direction of the combustion gas along the suction surface 34 as it approaches the suction surface 34.

[0028] FIG. 3 is an enlarged view of the vicinity of the leading edge 30 in the cross section shown in FIG. As shown in FIG. 3 , in a cross section perpendicular to the blade height direction, the blade surface 37 of the blade body 20 (the outer surface of the blade body 20, i.e., the surface composed of the suction surface 34 and the pressure surface 38) includes a circular arc 70 that passes through the leading edge 30 and has a constant radius of curvature, and a curved portion 72 that connects to the arc 70 on the suction surface 34 side of the blade body 20 and has a larger radius of curvature than the arc 70. Here, if the position where the suction surface-side bulkhead 24 connects to the inner surface of the suction surface-forming wall 36 is P1, the position of the boundary between the arc 70 and the curved portion 72 is P2, the distance between the leading edge 30 and position P1 is A1, and the distance between the leading edge 30 and position P2 is A2, then A1 > A2. In the example shown, position P1 is located outside a circle C1 that includes the circular arc 70. In the illustrated example, in a cross section perpendicular to the blade height direction, position P1 more specifically refers to the center position of the thickness of the negative pressure surface side partition wall 24 at the position where the inner surface 44 of the negative pressure surface forming wall 36 and the negative pressure surface side partition wall 24 are connected.

[0029] As shown in FIG. 3 , in a cross section perpendicular to the blade height direction, if a position on the back side of the leading edge 30 corresponding to the leading edge 30 on the inner surface 39 of the blade main body 20 (a surface formed by the inner surface 44 of the suction surface forming wall 36 and the inner surface 45 of the pressure surface forming wall 42) (the intersection point between the inner surface 39 and a straight line passing through the leading edge 30 and perpendicular to the blade surface 37) is denoted as P3, the inner surface 39 of the blade main body 20 includes a circular arc 74 with a constant radius of curvature that passes through position P3, and a curved portion 76 that connects to the arc 74 on the suction surface 34 side of the blade main body 20 and has a larger radius of curvature than the arc 74. Here, if the position of the boundary between the arc 74 and the curved portion 76 is denoted as P4, the distance between position P1 and position P3 is denoted as A3, and the distance between position P3 and position P4 is denoted as A4, then A3 > A4 is satisfied. In the example shown, position P1 is located outside a circle C2 that includes the arc 74.

[0030] The flow of cooling air in the turbine stator blade 12A will be described below with reference to Fig. 4. Fig. 4 is a cross-sectional view in which the flow of cooling air in the cross section shown in Fig. 2 is indicated by arrows.

[0031] As shown in FIG. 4 , cooling air supplied from an outer cavity (not shown) to the internal space 28 of the pressure surface side insert 26 passes through a plurality of impingement cooling holes 64 formed in the pressure surface side insert 26 and is blown onto the inner surface 45 of the pressure surface forming wall 42, thereby impingement cooling the inner surface 45 of the pressure surface forming wall 42.

[0032] A portion of the cooling air that has passed through the multiple impingement cooling holes 64 to perform impingement cooling on the pressure surface forming wall 42 passes sequentially through a gap 60a between the pressure surface side insert 26 and the pressure surface forming wall 42, a gap 60b between the pressure surface side insert 26 and the suction surface forming wall 36, and a gap 60c between the pressure surface side insert 26 and the suction surface side partition wall 24, and is supplied to the multiple impingement cooling holes 54 in the suction surface side partition wall 24. In other words, the gaps 60a, 60b, and 60c form a passage for cooling air from the impingement cooling hole 64 to the impingement cooling hole 54.

[0033] Another portion of the cooling air that has passed through the multiple impingement cooling holes 64 to perform impingement cooling on the inner surface 45 of the pressure surface forming wall 42 passes sequentially through a gap 60a between the pressure surface side insert 26 and the pressure surface forming wall 42, a gap 60d between the pressure surface side insert 26 and the leading edge partition wall 22, and a gap 60c between the pressure surface side insert 26 and the suction surface side partition wall 24, and is supplied to the multiple impingement cooling holes 54 in the suction surface side partition wall 24. In other words, the gaps 60a, 60d, and 60c form a passage for cooling air from the impingement cooling hole 64 to the impingement cooling hole 54.

[0034] The cooling air supplied from gap 60c to the plurality of impingement cooling holes 54 passes through the plurality of impingement cooling holes 54 and suction surface cavity 50 in this order, and is blown onto the inner surface 44 of the suction surface forming wall 36, thereby impingement cooling the inner surface 44 of the suction surface forming wall 36. The cooling air that has passed through the plurality of impingement cooling holes 54 and performed impingement cooling on the suction surface forming wall 36 is discharged to the outside of the blade main body 20 through the above-mentioned plurality of film cooling holes 58 formed in the suction surface forming wall 36, and performs film cooling on the suction surface 34 downstream of the film cooling holes 58 in the flow direction of the combustion gas.

[0035] The effects achieved by the turbine vane 12A will be described below. In the above-described turbine vane 12A, at least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes 64 of the pressure surface side insert 26 passes through the gaps 60a, 60b, 60c and the suction surface side impingement cooling holes 54 in this order to impinge cool the inner surface 44 of the suction surface forming wall 36, and at least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes 64 of the pressure surface side insert 26 passes through the gaps 60a, 60d, 60c and the suction surface side impingement cooling holes 54 in this order to impinge cool the inner surface 44 of the suction surface forming wall 36. In this way, the cooling air that has passed through the pressure surface side impingement cooling holes 64 of the pressure surface side insert 26 impingement cools the inner surface 45 of the pressure surface forming wall 42, and then passes through the suction surface side impingement cooling holes 54 of the suction surface side partition wall 24 to impingement cool the inner surface 44 of the suction surface forming wall 36.

[0036] In this way, by reusing the cooling air used for impingement cooling of the inner surface 45 of the pressure surface forming wall 42 for impingement cooling of the inner surface 44 of the suction surface side bulkhead, the amount of cooling air used to cool the turbine stator vane 12A (cooling air volume) can be reduced. Furthermore, because the suction surface side bulkhead 24 and the blade body 20 are integrally formed by casting, the problem of cooling air leakage from the gap between the rib-like wall and the suction surface side insert in the configuration described in Patent Document 1 does not occur, and therefore impingement cooling of the inner surface 44 of the suction surface forming wall 36 can be effectively performed with a small amount of cooling air. This allows the amount of cooling air used to cool the turbine stator vane 12A (cooling air volume) to be effectively reduced.

[0037] Furthermore, in the above-described turbine vane 12A, the pressure surface forming wall 42 does not have a film cooling hole that communicates the pressure surface side cavity 52 with the outside of the blade body 20, and the suction surface 34 has a film cooling hole 58 that communicates the suction surface side cavity 50 with the outside of the blade body 20. This allows the cooling air that has been used for impingement cooling of the inner surface 45 of the pressure surface forming wall 42 to be efficiently reused for impingement cooling of the inner surface 44 of the suction surface forming wall 36. Furthermore, even if the pressure of the cooling air drops 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 suction surface forming wall 36, the pressure of the combustion gas around the blade main body 20 is lower on the suction surface side than on the pressure surface side, so that film cooling of the suction surface 34 can be performed by discharging the cooling air to the outside of the blade main body 20 from the film cooling holes 58 formed in the suction surface forming wall 36 without excessively increasing the pressure of the cooling air supplied to the pressure surface-side insert 26. This makes it possible to effectively cool the pressure surface forming wall 42 and the suction surface forming wall 36 with a small amount of cooling air.

[0038] Generally, the leading edge 30 of the blade main body 20 and its vicinity are prone to high combustion gas pressure. However, in the turbine stator vane 12A, the suction surface side partition wall 24 extends from the inner surface 44 of the suction surface forming wall 36 to the leading edge partition wall 22. This allows the pressure in the space behind the leading edge 30 of the blade main body 20 (the pressure near position P3) to be set to the relatively high pressure of the cooling air before second-stage impingement cooling. Therefore, compared to a case in which the suction surface side partition wall 24 extends from the inner surface 45 of the pressure surface forming wall 42 to the leading edge partition wall 22 (see FIG. 5, for example), the pressure behind the leading edge 30 of the blade main body 20 can be made higher. Therefore, even if a hole is formed at the leading edge 30 of the blade main body 20 due to thermal damage or the like, the high pressure of the cooling air before second-stage impingement cooling can prevent high-temperature combustion gas from flowing into the interior of the blade main body 20, thereby preventing damage to the interior of the turbine stator vane 12A.

[0039] Furthermore, in the configuration described using Figure 3, the pressure of the combustion gas is likely to be particularly high in the portion of the arc 70 that passes through the leading edge 30 of the blade body 20. Therefore, by satisfying A1>A2 as described above (and / or by satisfying A3>A4), even if a hole is opened at the position of the arc 70 of the blade body 20 due to thermal damage, the high pressure of the cooling air before the second stage impingement cooling is performed can prevent the inflow of high-temperature combustion gas into the interior of the blade body 20, and damage to the interior of the turbine stator vane 12A can be suppressed.

[0040] The present disclosure is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0041] 5, one end of the suction surface side partition wall 24 may be connected to the inner surface 45 of the pressure surface forming wall 42. In this case, in a cross section perpendicular to the blade height direction, the suction surface side partition wall 24 may be formed only by a curved portion 24c that is convex toward the suction surface side.

[0042] The contents described in each of the above embodiments can be understood, for example, as follows.

[0043] (1) A gas turbine vane (e.g., the above-described turbine vane 12A) according to at least one embodiment of the present disclosure has: a blade body (e.g., the above-mentioned blade body 20) including a suction surface forming wall (e.g., the above-mentioned suction surface forming wall 36) that forms a suction surface (e.g., the above-mentioned suction surface 34), and a pressure surface forming wall (e.g., the above-mentioned pressure surface forming wall 42) that forms a pressure surface (e.g., the above-mentioned pressure surface 38) and forms an intra-blade cavity (e.g., the above-mentioned intra-blade cavity 40) between the suction surface forming wall and the blade body (e.g., the above-mentioned blade body 20); a leading edge partition wall (e.g., the above-mentioned leading edge partition wall 22) that is formed integrally with the blade body and extends from the inner surface of the suction surface forming wall (e.g., the above-mentioned inner surface 44) to the inner surface of the pressure surface forming wall (e.g., the above-mentioned inner surface 45) and divides the blade cavity into a leading edge side cavity (e.g., the above-mentioned leading edge side cavity 46) and a trailing edge side cavity (e.g., the above-mentioned trailing edge side cavity 48); a suction surface side bulkhead (e.g., the above-mentioned suction surface side bulkhead 24) formed integrally with the blade body, extending in the leading edge side cavity from the inner surface of the blade body to the leading edge bulkhead to divide the leading edge side cavity into a suction surface side cavity (e.g., the above-mentioned suction surface side cavity 50) and a pressure surface side cavity (e.g., the above-mentioned pressure surface side cavity 52), and having formed therein suction surface side impingement cooling holes (e.g., the above-mentioned suction surface side impingement cooling holes 54) for cooling the suction surface forming wall; a tubular pressure surface side insert (e.g., the above-mentioned pressure surface side insert 26) inserted into the pressure surface side cavity so as to provide a first gap (e.g., the above-mentioned gap 60a) between the pressure surface side insert and the pressure surface forming wall and a second gap (e.g., the above-mentioned gap 60c) between the pressure surface side insert and the suction surface side partition wall, the pressure surface side insert having a pressure surface side impingement cooling hole (e.g., the above-mentioned pressure surface side impingement cooling hole 64) for cooling the pressure surface side wall; Equipped with At least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes of the pressure surface side insert is configured to pass through the first gap, the second gap, and the suction surface side impingement cooling holes to cool the suction surface forming wall.

[0044] According to the gas turbine stator vane described in (1) above, the cooling air used for impingement cooling of the inner surface of the pressure surface forming wall can be reused for impingement cooling of the inner surface of the suction surface side bulkhead, thereby reducing the amount of cooling air used to cool the gas turbine stator vane (cooling air volume). Furthermore, since the suction surface side bulkhead and the blade body are integrally formed, the problem of cooling air leakage from the gap between the rib-like wall and the suction surface side insert in the configuration described in Patent Document 1 does not occur, and therefore impingement cooling of the inner surface of the suction surface forming wall can be effectively performed with a small amount of cooling air. This effectively reduces the amount of cooling air used to cool the gas turbine stator vane (cooling air volume).

[0045] (2) In some embodiments, in the gas turbine vane described in (1), No film cooling holes that connect the pressure surface side cavity with the outside of the blade body are formed in the pressure surface forming wall, and film cooling holes (for example, the above-mentioned film cooling holes 58) that connect the suction surface side cavity with the outside of the blade body are formed in the suction surface forming wall.

[0046] According to the gas turbine vane described in (2) above, the cooling air used for impingement cooling of the inner surface of the pressure surface wall can be efficiently reused for impingement cooling of the inner surface of the suction surface wall. Furthermore, even if the pressure of the cooling air is reduced by performing two-stage impingement cooling, including impingement cooling of the inner surface of the pressure surface wall and impingement cooling of the inner surface of the suction surface forming liquid, the pressure of the combustion gas around the blade body is lower on the suction surface side than on the pressure surface side. Therefore, film cooling of the suction surface can be performed by discharging the cooling air to the outside of the blade body through the film cooling holes formed in the suction surface wall without excessively increasing the pressure of the cooling air supplied to the pressure surface insert. This allows the pressure surface wall and the suction surface wall to be effectively cooled with a small amount of cooling air.

[0047] (3) In some embodiments, in the gas turbine vane described in (1) or (2), The blade body and the suction side bulkhead are integrally formed by casting, and the pressure side insert is formed from sheet metal.

[0048] According to the gas turbine vane described in (3) above, the blade body and the suction surface side bulkhead are integrally formed, which eliminates the problem of cooling air leaking from the gap between the rib-like wall and the suction surface side insert in the configuration described in Patent Document 1, and therefore impingement cooling of the inner surface of the suction surface forming wall can be effectively performed with a small amount of cooling air. Also, by forming the pressure surface side insert from sheet metal, the gas turbine vane described in (1) or (2) above can be easily manufactured.

[0049] (4) In some embodiments, in the gas turbine vane according to any one of (1) to (3), The suction surface side partition wall extends from the inner surface of the suction surface forming wall to the leading edge partition wall.

[0050] The leading edge of the blade body and its vicinity are prone to high combustion gas pressure, but in the gas turbine vane described in (4) above (see, for example, FIG. 4), the pressure in the space behind the leading edge of the blade body can be set to the pressure of the cooling air before second-stage impingement cooling, so the pressure behind the leading edge of the blade body can be made higher compared to a case where the suction surface side bulkhead extends from the inner surface of the pressure surface forming wall to the leading edge bulkhead (see, for example, FIG. 5). Therefore, even if a hole is created at the leading edge of the blade body due to thermal damage, the high pressure of the cooling air before second-stage impingement cooling can prevent high-temperature combustion gas from flowing into the interior of the blade body, and damage to the interior of the gas turbine vane can be suppressed.

[0051] (5) In some embodiments, in the gas turbine vane described in (4), In a cross section perpendicular to the blade height direction, the blade surface of the blade body (for example, the above-mentioned blade surface 37) includes an arc (for example, the above-mentioned arc 70) that passes through the leading edge of the blade body (for example, the above-mentioned leading edge 30) and has a constant radius of curvature, and a curved portion (for example, the above-mentioned curved portion 72) that is connected to the arc on the suction surface side of the blade body and has a larger radius of curvature than the arc, In a cross section perpendicular to the blade height direction, if the position where the suction surface side bulkhead and the inner surface of the suction surface forming wall are connected is P1, the position of the boundary between the arc and the curved portion is P2, the distance between the leading edge and position P1 is A1, and the distance between the leading edge and position P2 is A2, then A1 > A2 is satisfied.

[0052] The pressure of the combustion gas is likely to be particularly high in the arc portion passing through the leading edge of the blade body. Therefore, by satisfying A1>A2 as described in (5) above, even if a hole is created at the position of the arc of the blade body due to thermal damage, the high pressure of the cooling air before the second stage impingement cooling can prevent the high-temperature combustion gas from flowing into the interior of the blade body, thereby preventing damage to the interior of the gas turbine stator vane.

[0053] (6) In some embodiments, in the gas turbine vane described in (4) or (5), In a cross section perpendicular to the blade height direction, if a position P3 is defined as a back side of the leading edge of the blade body (for example, the above-mentioned leading edge) on the inner surface of the blade body, the inner surface of the blade body includes an arc (for example, the above-mentioned arc 74) that passes through the position P3 and has a constant radius of curvature, and a curved portion (for example, the above-mentioned curved portion 76) that is connected to the arc on the side of the blade body forming the suction surface and has a larger radius of curvature than the arc, In a cross section perpendicular to the wing height direction, if the position of the boundary between the arc and the curved portion is P4, the distance between the position P1 and the position P3 is A3, and the distance between the position P3 and the position P4 is A4, then A3 > A4 is satisfied.

[0054] The pressure of the combustion gas is likely to be particularly high in the arc portion passing through the leading edge of the blade body. Therefore, by satisfying A3>A4 as described in (6) above, even if a hole is created at the position of the arc of the blade body due to thermal damage, the high pressure of the cooling air before the second stage impingement cooling can prevent the high-temperature combustion gas from flowing into the interior of the blade body, thereby preventing damage to the interior of the gas turbine stator vane.

[0055] (7) In some embodiments, in the gas turbine vane according to any one of (4) to (6), In a cross section perpendicular to the blade height direction, the suction surface side partition wall is curved in an S-shape and includes a first curved portion (for example, the above-mentioned first curved portion 24a) that extends along the suction surface forming wall and curves convexly toward the suction surface side, and a second curved portion (for example, the above-mentioned second curved portion 24b) that curves convexly toward the pressure surface side, the first curved portion being connected to a position on the leading edge partition wall on the suction surface forming wall side, and the second curved portion being connected to the inner surface of the suction surface forming wall.

[0056] According to the gas turbine vane described in (7) above, the effects achieved by the gas turbine vane described in any one of (4) to (6) above can be obtained, and the distance between the suction surface forming wall and the suction surface side bulkhead can be kept constant over a wide range, so that the inner surface of the suction surface forming wall can be effectively impingement cooled.

[0057] (8) In some embodiments, in the gas turbine stator vane described in (7), In a cross section perpendicular to the blade height direction, a portion of the pressure surface side insert facing the suction surface side partition wall (for example, the above-mentioned portion 26c) is formed in an S-shape along the suction surface side partition wall, and includes a third curved portion (for example, the above-mentioned third curved portion 26c1) that extends along the first curved portion of the suction surface side partition wall and curves convexly toward the suction surface side, and a fourth curved portion (for example, the above-mentioned fourth curved portion 26c2) that extends along the second curved portion of the suction surface side partition wall and curves convexly toward the pressure surface side.

[0058] According to the gas turbine vane described in (8) above, by forming the portion of the pressure surface insert facing the suction surface side bulkhead into an S-shape so as to fit along the suction surface side bulkhead, it is possible to obtain the effects of the gas turbine vane described in (7) above while suppressing an increase in pressure loss in the pressure surface side cavity.

[0059] (9) In some embodiments, in the gas turbine vane according to any one of (1) to (8), a third gap (for example, the above-mentioned gap 60d) is provided between the pressure surface side insert and the leading edge partition; At least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes of the pressure surface side insert is configured to pass through the first gap, the third gap, the second gap and the suction surface side impingement cooling holes to cool the suction surface forming wall.

[0060] According to the gas turbine vane described in (9) above, it is possible to obtain the effects achieved by the gas turbine vane described in any one of (1) to (8) above while suppressing an increase in pressure loss in the pressure surface side cavity.

[0061] (10) In some embodiments, in the gas turbine stator vane according to any one of (1) to (9), A film cooling hole communicating the pressure surface cavity with the outside of the blade body is formed at a connection portion (for example, the above-mentioned connection portion 25) where the suction surface forming wall and the suction surface side bulkhead are connected.

[0062] According to the gas turbine vane described above in (10), the connecting portion, which is difficult to achieve the cooling effect of impingement cooling, can be effectively cooled by using air passing through the film cooling holes.

[0063] (11) A gas turbine according to at least one embodiment of the present disclosure includes: A gas turbine vane according to any one of (1) to (10) above; A turbine rotor; a casing that houses the turbine rotor; Equipped with.

[0064] According to the gas turbine described in (11) above, the amount of cooling air used to cool the gas turbine stator blades can be reduced. [Explanation of symbols]

[0065] 2. Gas turbine 4 Compressor 6 Combustor 8 Turbine 9 rotor 10 Turbine casing 12, 12A Turbine stator blade (gas turbine stator blade) 16 Turbine blades 20 Wing body 22 Leading edge bulkhead 24 Suction side bulkhead 24a First curved section 24b Second curved section 24c curved section 26 Pressure side insert 26a,26b,26c,26d part 26c1 Third curved section 26c2 Fourth curve 27 Outer surface 28 Interior Space 30 leading edge 32 Trailing edge 34 Suction surface 36 Negative pressure surface forming wall 37 Wing surface 38 Pressure Surface 39, 44, 45 Interior 40 Wing cavity 42 Pressure surface forming wall 46 Leading edge cavity 48 Trailing edge cavity 50 Suction side cavity 52 Pressure side cavity 54 Suction side impingement cooling holes 58,59 Film cooling holes 64 Pressure surface side impingement cooling holes 65 impingement cooling holes 60a,60b,60c,60d Gap 70,74 arc 72,76 Curve section

Claims

1. A gas turbine stator vane, a blade body including a suction surface forming wall that forms a suction surface, and a pressure surface forming wall that forms a pressure surface and forms an intra-blade cavity between itself and the suction surface forming wall; a leading edge partition wall formed integrally with the blade body, extending from the inner surface of the suction surface forming wall to the inner surface of the pressure surface forming wall, and dividing the blade cavity into a leading edge side cavity and a trailing edge side cavity; a suction surface side bulkhead formed integrally with the blade body, extending from the inner surface of the blade body to the leading edge bulkhead in the leading edge side cavity to divide the leading edge side cavity into a suction surface side cavity and a pressure surface side cavity, and having suction surface side impingement cooling holes formed therein for cooling the suction surface forming wall; a tubular pressure surface side insert inserted into the pressure surface side cavity so as to define a first gap between itself and the pressure surface forming wall and a second gap between itself and the suction surface side partition wall, the pressure surface side insert having pressure surface side impingement cooling holes formed therein for cooling the pressure surface forming wall; Equipped with a gas turbine stator vane configured such that at least a portion of cooling air having passed through the pressure surface side impingement cooling holes of the pressure surface side insert passes through the first gap, the second gap, and the suction surface side impingement cooling holes to cool the suction surface forming wall.

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

3. 2. The gas turbine vane according to claim 1, wherein said blade body and said suction side bulkhead are integrally formed by casting, and said pressure side insert is formed of sheet metal.

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

5. In a cross section perpendicular to the blade height direction, the blade surface of the blade body includes a circular arc that passes through the leading edge of the blade body and has a constant radius of curvature, and a curved portion that is connected to the circular arc on the suction surface side of the blade body and has a larger radius of curvature than the circular arc, 5. The gas turbine vane according to claim 4, wherein, in a cross section orthogonal to the blade height direction, a position where the suction surface side bulkhead and an inner surface of the suction surface forming wall are connected is defined as P1, a position of a boundary between the arc and the curved portion is defined as P2, a distance between the leading edge and position P1 is defined as A1, and a distance between the leading edge and position P2 is defined as A2, where A1 > A2.

6. In a cross section perpendicular to the blade height direction, when a position P3 is defined as a back side of the leading edge of the inner surface of the blade body corresponding to the leading edge of the blade body, the inner surface of the blade body includes a circular arc that passes through the position P3 and has a constant radius of curvature, and a curved portion that is connected to the circular arc on the side of the blade body forming the suction surface and has a larger radius of curvature than the circular arc, 5. The gas turbine vane according to claim 4, wherein, in a cross section orthogonal to the blade height direction, a position where the suction surface side bulkhead and an inner surface of the suction surface forming wall are connected is defined as P1, a position of a boundary between the arc and the curved portion is defined as P4, a distance between the position P1 and the position P3 is defined as A3, and a distance between the position P3 and the position P4 is defined as A4, where A3 > A4 is satisfied.

7. A gas turbine vane as described in claim 4, wherein in a cross section perpendicular to the blade height direction, the negative pressure surface side bulkhead is curved in an S-shape and includes a first curved portion extending along the negative pressure surface forming wall and curved convexly toward the negative pressure surface side, and a second curved portion curved convexly toward the pressure surface side, the first curved portion being connected to a position on the negative pressure surface forming wall side of the leading edge bulkhead, and the second curved portion being connected to the inner surface of the negative pressure surface forming wall.

8. 8. The gas turbine vane according to claim 7, wherein in a cross section perpendicular to the blade height direction, a portion of the pressure surface side insert facing the suction surface side partition wall is formed in an S-shape along the suction surface side partition wall, and includes: a third curved portion extending along the first curved portion of the suction surface side partition wall and curved so as to be convex toward the suction surface side; and a fourth curved portion extending along the second curved portion of the suction surface side partition wall and curved so as to be convex toward the pressure surface side.

9. a third gap is provided between the pressure surface side insert and the leading edge partition; 2. The gas turbine vane according to claim 1, wherein at least a portion of the cooling air that has passed through the pressure surface side impingement cooling holes of the pressure surface side insert is configured to pass through the first gap, the third gap, the second gap, and the suction surface side impingement cooling holes to cool an inner surface of the suction surface forming wall.

10. 2. The gas turbine vane according to claim 1, wherein a film cooling hole communicating the pressure surface side cavity with the outside of the blade body is formed in a connection portion where the suction surface forming wall and the suction surface side bulkhead are connected.

11. A gas turbine vane according to any one of claims 1 to 10; A turbine rotor; a casing that houses the turbine rotor; A gas turbine comprising:

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