Stationary blade and gas turbine equipped with same

Abstract

To provide a stationary blade which can be efficiently cooled.SOLUTION: A stationary blade has a blade body, a plurality of blade air passages, and a plurality of rear-end air passages. The plurality of blade air passages are aligned toward a trailing-edge side from a forward-edge side of the blade body. Each of the plurality of rear-end air passages has a trailing-edge opening extending toward a trailing-edge from a rear-side air passage at side nearest the trailing-edge out of the plurality of blade air passage, and opened at the trailing-edges. When a region including a blade-height first side, and not including a blade-height second side out of the trailing-edges extending in a blade height direction is denoted as a first side region, a region separated from the first side region to the blade-height second side, and including the blade-height second side is denoted as a second side region, and opening areas of the trailing-edges per unit length in the blade height direction of the trailing-edge openings in the plurality of rear-end air passages are denoted as opening ratios, the opening ratio of the first side region is higher than that of the second side region.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a stator vane and a gas turbine equipped with the same. [Background technology]

[0002] A gas turbine includes a compressor that compresses air to generate compressed air, a combustor that burns fuel in the compressed air to generate combustion gas, and a turbine that is driven by the combustion gas. The turbine includes a turbine rotor that rotates around an axis line, and a turbine rotor that rotates around the axis line. Turbine Ro The turbine rotor has a rotor shaft centered on the axis and a plurality of rows of moving blades attached to the rotor shaft. The plurality of rows of moving blades are aligned in the axial direction along which the axis extends. Each row of moving blades has a plurality of moving blades aligned in the circumferential direction about the axis. The plurality of rows of moving blades are aligned in the axial direction and attached to the inner peripheral side of the turbine casing. Each of the plurality of rows of moving blades is aligned on the axis of any one of the plurality of rows of moving blades. Distributed to the downstream side Each stator blade row has a plurality of stator blades arranged in the circumferential direction about the axis.

[0003] The stator vane has a blade body that has an airfoil-shaped cross section perpendicular to the radial direction relative to the axis and extends radially, an inner shroud that is provided radially inside the blade body, and an outer shroud that is provided radially outside the blade body. The blade body of the stator vane is disposed in a combustion gas flow path through which combustion gas passes. The inner shroud defines the radially inner edge of the combustion gas flow path, and the outer shroud defines the radially outer edge of the combustion gas flow path.

[0004] The stationary blades of a gas turbine are exposed to high-temperature combustion gases, and therefore are generally cooled by air or the like.

[0005] For example, the blade body of a vane described in Patent Document 1 below is formed with multiple blade air passages and multiple trailing edge air passages through which cooling air can flow. All of the multiple blade air passages extend radially. The multiple blade air passages are aligned from the leading edge side to the trailing edge side of the blade body. The forward blade air passage, which is the blade air passage closest to the leading edge among the multiple blade air passages, has an inlet opening at its radially outer end. The rear cooling passage, which is the blade air passage adjacent to the forward blade air passage on the trailing edge side among the multiple blade air passages, communicates with the forward blade air passage at their radially inner portions. The multiple trailing edge air passages are aligned radially. All of the multiple trailing edge air passages extend from the rear blade air passage toward the trailing edge and open at the trailing edge. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 8-319852 Summary of the Invention [Problem to be solved by the invention]

[0007] With respect to the stator vanes of gas turbines, it is desirable to cool the stator vanes to improve their durability while reducing the amount of air used to cool the stator vanes.

[0008] Therefore, an object of the present disclosure is to provide a stator vane that can be effectively cooled by cooling air to improve durability while reducing the amount of cooling air used, and a gas turbine equipped with this stator vane. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the invention relates to a stator blade, A gas turbine includes a stator vane having a blade body whose cross section is airfoil-shaped and extending in a blade height direction having a directional component perpendicular to the cross section, an outer shroud provided on the first blade height side of a first blade height side and a second blade height side of the blade body in the blade height direction and configured to be attachable to a turbine casing, a plurality of blade air passages extending in the blade height direction within the blade body, and a plurality of aft end air passages aligned in the blade height direction. The aforementioned The blade has a leading edge and a trailing edge extending in the blade height direction. The multiple blade air passages are aligned from the leading edge side toward the trailing edge side. Of the multiple blade air passages, the front blade air passage, which is the blade air passage closest to the leading edge, has an inlet opening at its end on the first blade height side, through which cooling air can flow. The multiple blade air passages communicate with each other at one of their ends on the first blade height side and the second blade height side, so that the multiple blade air passages form a single serpentine passage that undulates in the blade height direction. The multiple aft end air passages extend from the aft blade air passage, which is the blade air passage closest to the trailing edge among the multiple blade air passages, toward the trailing edge and have trailing edge openings that open at the trailing edge. A first side region is a region of the trailing edge extending in the blade height direction that includes the end on the first blade height side but does not include the end on the second blade height side. A region of the trailing edge that is separated from the first side region toward the second blade height side and includes an end of the second blade height side is defined as a second side region. An opening area of ​​the trailing edge openings in the plurality of trailing end air passages per unit length of the trailing edge in the blade height direction is defined as an opening ratio. In this case, The aforementioned In the multiple rear end air passages The aforementioned The opening ratio of the trailing edge opening is higher in the first side region than in the second side region. The opening ratio of an intermediate region in the trailing edge between the first side region and the second side region in the wing height direction is higher than the opening ratio of the second side region and lower than the opening ratio of the first side region.

[0010] In recent years, methods have been studied to increase the blade height of the blade body, in other words, to increase the radial length of the blade body, in order to improve the performance of gas turbines. Increasing the radial length of the blade body increases the force that the blade body receives from the combustion gas, and also increases the moment that tends to rotate the radially inner end of the blade body downstream of the axis around the radially outer end of the blade body. This increase in moment requires increasing the strength of the radially outer portion around the trailing edge of the blade body. However, even if the moment increases, there is no need to increase the strength of the radially inner portion of the blade body, since this portion is located on the free end side of the stator vane.

[0011] Therefore, in this aspect, the opening ratio of the second side region is reduced to reduce the amount of cooling air used, while the opening ratio of the first side region is increased to improve the cooling performance of the first side region and prevent a decrease in strength around the first side region. Therefore, in this aspect, the stator blade can be effectively cooled, improving the durability of the stator blade while reducing the amount of cooling air used.

[0012] In order to achieve the above object, a gas turbine according to one aspect of the invention comprises: The turbine turbine includes a turbine rotor rotatable about an axis, a turbine casing covering an outer periphery of the turbine rotor, and a plurality of stator vane rows arranged in an axial direction along which the axis extends and attached to an inner periphery of the turbine casing. Each of the plurality of stator vane rows has a plurality of stator vanes arranged in a circumferential direction about the axis. Of the plurality of stator vane rows, a final stage stator vane row that is the stator vane row furthest downstream of the axial upstream and downstream sides in the axial direction has each of the plurality of stator vanes that are the stator vanes according to the one aspect. Each of the plurality of stator vanes that the final stage stator vane row has is attached to the turbine casing so that the blade height direction is radial with respect to the axis, the first blade height side is the radially outer side of the radially inner side and the radially outer side in the radial direction, and the side on which the trailing edge is located relative to the leading edge is the axially downstream side. [Effects of the Invention]

[0013] According to one aspect of the present disclosure, the stator blades can be effectively cooled with cooling air, thereby improving the durability of the stator blades while reducing the amount of cooling air used. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a schematic cross-sectional view of a gas turbine in one embodiment according to the present disclosure. [Figure 2] 1 is a cross-sectional view of a main portion of a gas turbine in an embodiment according to the present disclosure. FIG. [Figure 3] FIG. 2 is a cross-sectional view of a vane in an embodiment according to the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] Various embodiments of the present invention and modifications thereof will be described in detail below with reference to the drawings.

[0016] Gas Turbine Embodiment An embodiment of the gas turbine will be described with reference to FIGS.

[0017] As shown in FIG. 1, the gas turbine 1 in this embodiment includes a compressor 10 that compresses outside air A to generate compressed air Acom, a combustor 20 that burns fuel F from a fuel supply source in the compressed air Acom to generate combustion gas G, and a turbine 30 that is driven by the combustion gas G.

[0018] The compressor 10 has a compressor rotor 11 that rotates about an axis Ar, a compressor casing 15 that covers the compressor rotor 11, and multiple stator vane rows 18. The turbine 30 has a turbine rotor 31 that rotates about the axis Ar, a turbine casing 35 that covers the turbine rotor 31, and multiple stator vane rows 38. Note that, hereinafter, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction about the axis Ar is simply referred to as the circumferential direction Dc, and the direction perpendicular to the axis Ar is referred to as the radial direction Dr. One side of the axial direction Da is referred to as the axial upstream side Dau, and the opposite side is referred to as the axial downstream side Dad. Furthermore, the side of the radial direction Dr that approaches the axis Ar is referred to as the radially inner side Dri, and the opposite side is referred to as the radially outer side Dro.

[0019] The compressor 10 is disposed on the axial upstream side Dau with respect to the turbine 30 .

[0020] The compressor rotor 11 and the turbine rotor 31 are located on the same axis Ar and are connected to each other to form the gas turbine rotor 2. To this gas turbine rotor 2, for example, a rotor of a generator GEN is connected. The gas turbine 1 further includes an intermediate casing 6. This intermediate casing 6 is arranged between the compressor casing 15 and the turbine casing 35 in the axial direction Da. The compressor casing 15, the intermediate casing 6, and the turbine casing 35 are connected to each other to form the gas turbine casing 5.

[0021] As shown in FIGS. 1 and 2 , the compressor rotor 11 has a rotor shaft 12 extending in an axial direction Da about an axis Ar, and a plurality of rotor blade rows 13 attached to the rotor shaft 12. The plurality of rotor blade rows 13 are aligned in the axial direction Da. Each rotor blade row 13 is made up of a plurality of rotor blades aligned in a circumferential direction Dc. One of a plurality of stator blade rows 18 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 13. Each stator blade row 18 is provided inside a compressor casing 15. Each stator blade row 18 is made up of a plurality of stator blades aligned in the circumferential direction Dc.

[0022] The turbine rotor 31 has a rotor shaft 32 extending in the axial direction Da centered on the axis Ar, and a plurality of rotor blade rows 33 attached to the rotor shaft 32. The plurality of rotor blade rows 33 are aligned in the axial direction Da. Each rotor blade row 33 is made up of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 38 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 33. Each stator blade row 38 is provided inside the turbine casing 35. Each stator blade row 38 is made up of a plurality of stator blades aligned in the circumferential direction Dc.

[0023] The annular space between the outer circumferential side of the rotor shaft 32 and the inner circumferential side of the turbine casing 35, in which the rotor blade row 33 and the stator blade row 38 are arranged in the axial direction Da, forms a combustion gas flow path 39 through which the combustion gas G from the combustor 20 flows.

[0024] As shown in Fig. 2, the turbine casing 35 has a turbine casing main body 36 and a plurality of ring segments 37. The ring segments 37 are located on the radially outer side Dro of the rotor blade row 33 and face the rotor blade row 33 in the radial direction Dr. The ring segments 37 define the edge of the radially outer side Dro of the combustion gas flow path 39 at the position in the axial direction Da where the rotor blade row 33 is located. The turbine casing main body 36 is cylindrical and centered on the axis Ar so as to surround the outer periphery of the turbine rotor 31. A plurality of stator blade rows 38 and a plurality of ring segments 37 are attached to the inner peripheral portion of the turbine casing main body 36.

[0025] The combustor 20 is attached to the intermediate casing 6. The combustor 20 has a transition piece (or combustion piece) 22 in which fuel F is burned, and a plurality of burners 21 that inject fuel into the transition piece 22.

[0026] As shown in FIG. 1 , the compressor 10 compresses outside air A to generate compressed air Acom. This compressed air Acom flows into the combustor 20. Fuel F is supplied to the combustor 20. A burner 21 of the combustor 20 injects the compressed air Acom together with the fuel F into the transition piece 22. Inside the transition piece 22, the fuel F is combusted in the compressed air Acom, generating high-temperature, high-pressure combustion gas G. This combustion gas G is sent from the transition piece 22 to a combustion gas flow path 39 in the turbine 30. As the combustion gas G flows through the combustion gas flow path 39 toward the axial downstream side Dad, it rotates the turbine rotor 31. This rotation of the turbine rotor 31 rotates the rotor of the generator GEN connected to the gas turbine rotor 2. As a result, the generator GEN generates electricity.

[0027] Hereinafter, the stator blades constituting the stator blade row 38 on the most axially downstream side Dad among the plurality of stator blade rows 38 will be described.

[0028] "Embodiment of Stator Blade" Hereinafter, an embodiment of the stationary blade will be described with reference to FIGS.

[0029] As shown in FIG. 3, the stator vane 40 of this embodiment includes a blade body 41, an outer shroud 45o, an inner shroud 45i, and a sealing device 49. The blade body 41 has a blade-shaped cross section and extends in a blade height direction Dh having a component perpendicular to the cross section. The outer shroud 45o is provided at an end of a first blade height side Dh1, which is one side of the blade body 41 in the blade height direction Dh. The inner shroud 45i is provided at an end of a second blade height side Dh2, which is the other side of the blade body 41 in the blade height direction Dh. The blade body 41, the inner shroud 45i, and the outer shroud 45o are integrally formed by casting or the like. The sealing device 49 is provided on the second blade height side Dh2 of the inner shroud 45i.

[0030] When the stator vane 40 is attached to the turbine casing 35 (see FIG. 2), the blade height direction Dh becomes the radial direction Dr. Also, a first blade height side Dh1, which is one side of the blade height direction Dh, becomes the radial outside Dro, and a second blade height side Dh2, which is the other side of the blade height direction Dh, becomes the radial outside Dro. Inside Therefore, the inner shroud 45i is provided on the radially inner side Dri of the blade body 41, and the outer shroud 45o is provided on the radially outer side Dro of the blade body 41. Therefore, in this embodiment, the blade height direction Dh is the radial direction Dr, and the blade height first side Dh1 is the radial direction Outside Dro , the second blade height Dh2 in the radial direction Inside Dri This is sometimes the case.

[0031] The sealing device 49 provides a seal between the stator vane 40 and the rotor shaft 32 in the radial direction Dr. The outer shroud 45o, together with the ring segment 37, defines a portion of the edge of the radially outer side Dro of the annular combustion gas flow path 39. The inner shroud 45i defines a portion of the edge of the radially inner side Dri of the annular combustion gas flow path 39.

[0032] The outer shroud 45o has an outer shroud main body 46o and a hook portion 48o. The outer shroud main body 46o is a plate-shaped member that extends in a direction including a directional component perpendicular to the radial direction Dr, which is the blade height direction Dh. The outer shroud main body 46o has a gas path surface 47op and a counter-gas path surface 47oo. The gas path surface 47op faces the radially inner side Dri, which is the blade height second side Dh2, and the counter-gas path surface 47oo faces the radially outer side Dro, which is the blade height first side Dh1. The counter-gas path surface 47oo is back-to-back with the gas path surface 47op. The hook portion 48o is provided on the counter-gas path surface 47oo of the outer shroud main body 46o. The hook portion 48o is configured to be attachable to the turbine casing main body 36.

[0033] The inner shroud 45i includes an inner shroud main body 46i and a seal mounting portion 48i. The inner shroud main body 46i is a plate-shaped member extending in a direction including a directional component perpendicular to the radial direction Dr, which is the blade height direction Dh. The inner shroud main body 46i includes a gas path surface 47ip and a counter-gas path surface 47io. The gas path surface 47ip faces the radially outer side Dro, which is the blade height first side Dh1, and is the surface that comes into contact with the combustion gas G. The counter-gas path surface 47io faces the radially inner side Dri, which is the blade height second side Dh2. The counter-gas path surface 47io is back-to-back with the gas path surface 47ip. The seal mounting portion 48i is provided on the counter-gas path surface 47io of the inner shroud main body 46i. The seal mounting portion 48i is configured to hold a sealing device 49.

[0034] As shown in Fig. 4, the blade surface, which is the outer surface of the blade body 41, has a leading edge 42f, a trailing edge 42b, a suction surface 43n which is a convex surface, and a pressure surface 43p which is a concave surface. The leading edge 42f and the trailing edge 42b are located at the connection between the suction surface 43n and the pressure surface 43p. The leading edge 42f, the trailing edge 42b, the suction surface 43n, and the pressure surface 43p all extend in the radial direction Dr, which is the blade height direction Dh. When the stator vane 40 is attached to the turbine casing 35, the leading edge 42f is located on the axial upstream side Dau of the trailing edge 42b.

[0035] The blade body 41 is disposed in a combustion gas flow path 39 through which the combustion gas G passes. The blade body 41 has a plurality of blade air passages 50 extending in the blade height direction Dh within the blade body 41, and a plurality of trailing end air passages 55 aligned in the blade height direction Dh within the blade body 41.

[0036] The multiple blade air passages 50 formed in the blade body 41 are aligned along the camber line CL of the blade body 41. Of the multiple blade air passages 50, the blade air passage 50 located furthest upstream along the axial direction (Dau), in other words, the blade air passage 50 closest to the leading edge 42f, is referred to as the front blade air passage 51, and the blade air passage 50 located furthest downstream along the axial direction (Dad) is referred to as the rear blade air passage 52. The multiple blade air passages 50 are connected to each other at either the end of the first blade height side (Dh1) or the end of the second blade height side (Dh2) so as to form a serpentine passage in which the passage undulates in the blade height direction (Dh). The stator vane 40 of this embodiment has two blade air passages 50, which is an even number. Therefore, in this embodiment, the front blade air passage 51 and the rear blade air passage 52 are adjacent to each other.

[0037] The forward blade air passage 51 has an inlet opening 51o that opens on the anti-gas path surface 47oo of the outer shroud 45o. The forward blade air passage 51 extends from this inlet opening 51o toward the second blade height side Dh2. The turbine casing body 36 is formed with a casing air passage 36p through which the cooling air Acool can flow. The cooling air Acool flowing out of the casing air passage 36p of the turbine casing body 36 flows into the forward blade air passage 51 from the inlet opening 51o of the forward blade air passage 51. As the cooling air Acool flows through the forward blade air passage 51, it convectively cools the area around the forward blade air passage 51 within the blade body 41. The forward blade air passage 51 and the aft blade air passage 52 communicate with each other at their ends on the second blade height side Dh2. Therefore, the cooling air Acool that has passed through the front blade air passage 51 flows into the rear blade air passage 52 from the end of the rear blade air passage 52 on the second blade height side Dh2, and flows to the first blade height side Dh1 within this rear blade air passage 52. In the process of flowing through this rear blade air passage 52, the cooling air Acool convectively cools the area around the rear blade air passage 52 within the blade body 41.

[0038] The multiple trailing end air passages 55 extend from the rear blade air passage 52 toward the trailing edge 42b. The multiple trailing end air passages 55 have trailing edge openings 55o that open at the trailing edge 42b. The cooling air Acool flowing through the rear blade air passage 52 flows into the multiple trailing end air passages 55. As the cooling air Acool flows through these trailing end air passages 55, it convectively cools the area around the trailing end air passages 55 within the blade body 41. The cooling air Acool that has passed through the trailing end air passage 55 is ejected into the combustion gas flow path 39 from the trailing edge openings 55o.

[0039] Here, the region of the trailing edge 42b extending from the end of the blade height first side Dh1 of the trailing edge 42b toward the blade height second side Dh2, within 25% of the length of the trailing edge 42b in the blade height direction Dh, is referred to as the first side region R1. The region of the trailing edge 42b extending from the end of the blade height second side Dh2 of the trailing edge 42b toward the blade height first side Dh1, within 25% of the length of the trailing edge 42b in the blade height direction Dh, is referred to as the second side region R2. Furthermore, the region of the trailing edge 42b between the first side region R1 and the second side region R2 in the blade height direction Dh is referred to as the intermediate region RM. The opening area of ​​the trailing edge openings 55o of the multiple trailing end air passages 55 per unit length of the trailing edge 42b in the blade height direction Dh is referred to as the opening ratio.

[0040] In this embodiment, the opening area of ​​the trailing edge openings 55o is higher in the first side region R1 than in the second side region R2. In this embodiment, the opening areas of the trailing edge openings 55o in each of the multiple trailing end air passages 55 are the same. Therefore, in this embodiment, the number of trailing edge openings 55o is greater in the first side region R1 than in the second side region R2. Specifically, the number of trailing edge openings 55o in the second side region R2 is 0; in other words, the opening area ratio of the second side region R2 is 0. On the other hand, multiple trailing edge openings 55o are formed in the intermediate region RM and the first side region R1. The number of trailing edge openings 55o in the first side region R1 is three or more times the number of trailing edge openings 55o in the intermediate region RM; in other words, the opening area ratio of the trailing edge openings 55o in the first side region R1 is three or more times the opening area ratio of the trailing edge openings 55o in the intermediate region RM.

[0041] In recent years, methods have been considered to increase the blade height of the blade body 41, in other words, to increase the length of the radial direction Dr of the blade body 41, in order to improve the performance of gas turbines. Increasing the length of the radial direction Dr of the blade body 41 increases the force that the blade body 41 receives from the combustion gas G, and also increases the moment that tends to rotate the end of the radially inner direction Dri of the blade body 41 toward the axial downstream side Dad around the end of the radially outer direction Dro of the blade body 41. When the moment increases in this way, it is necessary to increase the strength of the radially outer portion Dro around the trailing edge 42b of the blade body 41. On the other hand, even if the moment increases, there is no need to increase the strength of the radially inner portion Dri of the blade body 41, because this portion is on the free end side of the stator vane 40.

[0042] Therefore, in this embodiment, the opening rate of the second side region R2 is reduced to reduce the amount of cooling air Acool used, while the opening rate of the first side region R1 is increased to improve the cooling performance of the first side region R1 and prevent a decrease in strength around the first side region R1. Therefore, in this embodiment, the stator blade 40 can be effectively cooled, improving the durability of the stator blade 40 while reducing the amount of cooling air Acool used. In particular, in this embodiment, the opening rate of the second side region R2 is set to 0 to reduce the amount of cooling air Acool used, and the opening rate of the first side region R1 is set to three or more times the opening rate of the intermediate region RM to improve the cooling performance of the first side region R1, so that the stator blade 40 can be cooled extremely effectively.

[0043] Here, methods for increasing the opening ratio include increasing the opening area of ​​the trailing edge openings 55o and increasing the number of the trailing edge openings 55o. Increasing the number of the trailing edge openings 55o in the first side region R1 and narrowing the pitch between the trailing edge openings 55o in the first side region R1 as in the present embodiment allows for more uniform cooling around the first side region R1 than by increasing the opening area of ​​the trailing edge openings 55o.

[0044] When the number of blade air passages 50 is an even number as in the present embodiment, the cooling air Acool flows toward the blade height first side Dh1 in the aft blade air passage 52, which is the blade air passage 50 closest to the trailing edge 42b. Therefore, in the aft blade air passage 52, the temperature of the cooling air Acool flowing in the blade height first side Dh1 is higher than the temperature of the cooling air Acool flowing in the blade height second side Dh2. When the area around the first side region R1 is cooled with high-temperature cooling air Acool, the opening ratio of the trailing edge openings 55o must be higher than when the area around the first side region R1 is cooled with low-temperature cooling air Acool. From this perspective, when the number of blade air passages 50 is even, the opening ratio of the trailing edge openings 55o in the multiple aft end air passages 55 should be higher in the first side region R1 than in the second side region R2.

[0045] "Modified Stator Blade" The stator vane 40 in the above embodiment is a stator vane 40 that constitutes the stator vane row 38 that is located most downstream along the axis Dad among the multiple stator vane rows 38. However, the stator vane according to the present disclosure may also be a stator vane that constitutes a stator vane row 38 other than the stator vane row 38 that is located most downstream along the axis Dad among the multiple stator vane rows 38. For example, the stator vane according to the present disclosure may also be a stator vane that constitutes a stator vane row 38 that is located one row upstream along the axis Dau from the stator vane row 38 that is located most downstream along the axis Dad among the multiple stator vane rows 38.

[0046] The stator vane 40 in the above embodiment has an even number of two blade air passages 50. However, the stator vane according to the present disclosure may have three or more blade air passages 50. However, it is preferable that the number of blade air passages 50 is an even number.

[0047] In the above embodiment, the aperture ratio of the second side region R2 is 0. However, as long as the aperture ratio of the first side region R1 is higher than the aperture ratio of the second side region R2, the aperture ratio of the second side region R2 does not have to be 0.

[0048] In the above embodiment, the number of the trailing edge openings 55o is increased in order to increase the opening ratio. However, the opening area of ​​the trailing edge openings 55o may be increased in order to increase the opening ratio. And openWhen increasing the opening ratio, it is preferable to increase the number of trailing edge openings 55o from the viewpoint of uniform cooling, as described above.

[0049] In the above embodiment, the first side region R1 is a region within the trailing edge 42b that extends from the end of the blade height first side Dh1 of the trailing edge 42b to the blade height second side Dh2, and that is within 25% of the length of the trailing edge 42b in the blade height direction Dh. Also, in the above embodiment, the second side region R2 is a region within the trailing edge 42b that extends from the end of the blade height second side Dh2 of the trailing edge 42b to the blade height first side Dh1, and that is within 25% of the length of the trailing edge 42b in the blade height direction Dh. However, the value of 25% may be changed as appropriate within a range from 15% to 40% depending on the temperature of the combustion gas G around the stator vane 40, the temperature of the cooling air Acool flowing into the stator vane 40, the number of blade air passages 50 that the stator vane 40 has, and the position of the stator vane row 38 formed by this stator vane 40. For example, within the trailing edge 42b, the region from the end of the first blade height side Dh1 of the trailing edge 42b to the second blade height side Dh2, within 30% of the length of the trailing edge 42b in the blade height direction Dh, may be defined as the first side region R1, and within the trailing edge 42b, the region from the end of the second blade height side Dh2 of the trailing edge 42b to the first blade height side Dh1, within 20% of the length of the trailing edge 42b in the blade height direction Dh, may be defined as the second side region R2.

[0050] The present disclosure is not limited to the embodiments described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents.

[0051] "Addendum" The stationary blades in the above-described embodiment and modified examples can be understood, for example, as follows.

[0052] (1) The stationary blade in the first aspect is A gas turbine includes a stator vane 40 having a blade-shaped cross section and extending in a blade height direction Dh having a component perpendicular to the cross section, a blade body 41, an outer shroud 45o provided on the first blade height side Dh1 of a first blade height side Dh1 and a second blade height side Dh2 in the blade height direction Dh of the blade body 41 and configured to be attachable to a turbine casing 35, a plurality of blade air passages 50 extending in the blade height direction Dh within the blade body 41, and a plurality of trailing end air passages 55 aligned in the blade height direction Dh. The blade body 41 has a leading edge 42f and a trailing edge 42b extending in the blade height direction Dh. The plurality of blade air passages 50 are aligned from the leading edge 42f side toward the trailing edge 42b side. Of the plurality of blade air passages 50, the front blade air passage 51, which is the blade air passage 50 closest to the leading edge 42f, has an inlet opening 51o at its end on the blade height first side Dh1, through which cooling air Acool can flow. Adjacent blade air passages 50 communicate with each other at one of their ends on the blade height first side Dh1 and the blade height second side Dh2, so that the plurality of blade air passages 50 form a serpentine passage that undulates in the blade height direction Dh. The plurality of trailing end air passages 55 extend from the rear blade air passage 52, which is the blade air passage 50 closest to the trailing edge 42b, toward the trailing edge 42b and have a trailing edge opening 55o that opens at the trailing edge 42b. A first side region R1 is a region of the trailing edge 42b extending in the blade height direction Dh that includes an end of the blade height first side Dh1 but does not include an end of the blade height second side Dh2. A second side region R2 is a region of the trailing edge 42b that is separated from the first side region R1 toward the blade height second side Dh2 and includes the end of the blade height second side Dh2. The opening area of ​​the trailing edge openings 55o in the multiple trailing end air passages 55 per unit length of the trailing edge 42b in the blade height direction Dh is referred to as the aperture ratio. In this case, the aperture ratio of the trailing edge openings 55o in the multiple trailing end air passages 55 is higher in the first side region R1 than in the second side region R2.

[0053] In recent years, methods have been considered to increase the blade height of the blade body 41, in other words, to increase the length of the radial direction Dr of the blade body 41, in order to improve the performance of gas turbines. Increasing the length of the radial direction Dr of the blade body 41 increases the force that the blade body 41 receives from the combustion gas G, and also increases the moment that tends to rotate the end of the radially inner direction Dri of the blade body 41 toward the axial downstream side Dad around the end of the radially outer direction Dro of the blade body 41. When the moment increases in this way, it is necessary to increase the strength of the radially outer portion Dro around the trailing edge 42b of the blade body 41. On the other hand, even if the moment increases, there is no need to increase the strength of the radially inner portion Dri of the blade body 41, because this portion is on the free end side of the stator vane 40.

[0054] Therefore, in this embodiment, the opening rate of the second side region R2 is reduced to reduce the amount of cooling air Acool used, while the opening rate of the first side region R1 is increased to improve the cooling performance of the first side region R1 and reduce the decrease in strength around the first side region R1. Therefore, in this embodiment, the stator blade 40 can be effectively cooled, improving the durability of the stator blade 40 while reducing the amount of cooling air Acool used.

[0055] (2) The stationary blade in the second aspect is In the vane 40 of the first embodiment, the number of the plurality of trailing edge openings 55o is greater than that of the second side region R2. The above There is more of it in one area, R1.

[0056] Methods for increasing the opening ratio include increasing the opening area of ​​the trailing edge openings 55o and increasing the number of the trailing edge openings 55o. Increasing the number of the trailing edge openings 55o in the first side region R1 and narrowing the pitch between the trailing edge openings 55o in the first side region R1 as in this embodiment allows for more uniform cooling around the first side region R1 than with a method that increases the opening area of ​​the trailing edge openings 55o.

[0057] (3) The stationary blade in the third aspect is In the vane 40 in the first or second embodiment, the opening ratio of the intermediate region RM between the first side region R1 and the second side region R2 in the blade height direction Dh within the trailing edge 42b is higher than the opening ratio of the second side region R2 and lower than the opening ratio of the first side region R1.

[0058] (4) The stationary blade in the fourth aspect is In the vane 40 according to the third aspect, the opening ratio of the first side region R1 is three times or more higher than the opening ratio of the intermediate region RM.

[0059] In this embodiment, the cooling performance around the first side region R1 in the blade body 41 can be improved.

[0060] (5) The stationary blade in the fifth aspect is In the vane 40 according to any one of the first to fourth aspects, the opening ratio of the second side region R2 is 0. Stator blade 40.

[0061] In this embodiment, the amount of cooling air Acool used can be reduced.

[0062] (6) The stator blade in the sixth aspect is In the stator vane 40 according to any one of the first to fifth aspects, the first side region R1 is a region in the trailing edge 42b that is within 25% of the length of the trailing edge 42b in the blade height direction Dh from an end of the trailing edge 42b on the first blade height side Dh1 toward the second blade height side Dh2. The second side region R2 is a region in the trailing edge 42b that is within 25% of the length of the trailing edge 42b in the blade height direction Dh from an end of the trailing edge 42b on the second blade height side Dh2 toward the first blade height side Dh1.

[0063] (7) The stationary blade in the seventh aspect is In the vane 40 according to any one of the first to sixth aspects, the number of the plurality of blade air passages 50 is an even number.

[0064] The cooling air Acool that flows into the front blade air passage 51 from the inlet opening 51o of the front blade air passage 51, which is the blade air passage 50 closest to the leading edge 42f among the multiple blade air passages 50, flows through this front blade air passage 51 to the blade height second side Dh2. When the number of multiple blade air passages 50 is even, the cooling air Acool flows to the blade height first side Dh1 in the rear blade air passage 52, which is the blade air passage 50 closest to the trailing edge 42b. Therefore, in the rear blade air passage 52, the temperature of the cooling air Acool flowing in the blade height first side Dh1 is higher than the temperature of the cooling air Acool flowing in the blade height second side Dh2. When the area around the first side region R1 is cooled with high-temperature cooling air Acool, the opening ratio of the trailing edge opening 55o needs to be larger than when the area around the first side region R1 is cooled with low-temperature cooling air Acool. Therefore, from this point of view, especially when there is an even number of blade air passages 50, the opening rate of the trailing edge openings 55o in the trailing end air passages 55 should be higher in the first side region R1 than in the second side region R2.

[0065] (8) In the eighth aspect, the stator blade is In the vane 40 according to any one of the first to sixth embodiments, the number of the plurality of blade air passages 50 is two.

[0066] The gas turbine in the above embodiment can be understood as follows, for example. (9) A gas turbine according to a ninth aspect includes: The turbine turbine includes a turbine rotor 31 that can rotate about an axis Ar, a turbine casing 35 that covers the outer periphery of the turbine rotor 31, and a plurality of stator blade rows 38 that are aligned in the axial direction Da along which the axis Ar extends and that are attached to the inner periphery of the turbine casing 35. On line ArAmong the plurality of stator vane rows 38, the final stage stator vane row 38, which is the stator vane row 38 on the most axially downstream side Dad out of the axially upstream side Dau and the axially downstream side Dad in the axial direction Da, has a plurality of stator vanes 40 arranged in the circumferential direction Dc relative to the axial direction Da. Each of the plurality of stator vanes 40 included in the final stage stator vane row 38 is the stator vane 40 according to any one of the first to eighth embodiments. On line Ar Each of the plurality of stator blades 40 of the final stage stator blade row 38 is attached to the turbine casing 35 so that the first blade height side Dh1 is the radially outer side Dro of the radially inner side Dri and the radially outer side Dro in the radial direction Dr, and the side where the trailing edge 42b is located relative to the leading edge 42f is the axial downstream side Dad. [Explanation of symbols]

[0067] 1: Gas turbine 2: Gas turbine rotor 5: Gas turbine casing 6: Intermediate casing 10: Compressor 11: Compressor rotor 12: Rotor shaft 13: Moving blade row 15: Compressor casing 18: Stator blade row 20: Combustor 21: Burner 22: Transition tube (or combustion tube) 30: Turbine 31: Turbine rotor 32: Rotor shaft 33: Moving blade row 35: Turbine casing 36: Turbine casing body 36p: Casing air passage 37: Split ring 38: Stator blade row 39: Combustion gas flow path 40: Stator blade 41: Wing body 42f: leading edge 42b: Trailing edge 43n: Negative pressure side 43p: Positive pressure side 45o: Outer shroud 46o: Outer shroud body 47op: Gas Pass Surface 47oo: Anti-gas pass surface 48o: Hook part 45i: Inner shroud 46i: Inner shroud body 47ip: Gas pass surface 47io: Anti-gas pass surface 48i: Seal mounting part 49: Sealing device 50: Wing air passage 51: Forward wing air passage 51o: Entrance opening 52: Rear wing air passage 55: Rear air passage 55o: Trailing edge opening A: Outside air Acom: Compressed air Acool: Cooling air G: Combustion gas F:Fuel CL: Camber line Ar: Axis line Da: Axial direction Dau: Axis upstream side Dad: Downstream of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner direction Dro: Radial outer side Dh: Wing height direction Dh1: First wing height Dh2: Wing height second side R1: First side area R2: Second side area RM: intermediate area

Claims

1. A stationary blade provided in a gas turbine, A wing body having a cross-sectional shape that forms an airfoil and extending in a wing height direction having a directional component perpendicular to the cross section; an outer shroud provided on the first blade height side of a first blade height side and a second blade height side in the blade height direction of the blade body, the outer shroud being configured to be attachable to a turbine casing; a plurality of blade air passages extending in the blade height direction within the blade body; a plurality of trailing edge air passages arranged in the wing height direction; and The wing body has a leading edge and a trailing edge extending in the wing height direction, the plurality of blade air passages are aligned from the leading edge side toward the trailing edge side, a front blade air passage, which is the blade air passage closest to the leading edge among the plurality of blade air passages, has an inlet opening at an end of the front blade air passage on the first blade height side, through which cooling air can flow, the plurality of blade air passages are configured to form a single serpentine passage undulating in the blade height direction, and adjacent blade air passages among the plurality of blade air passages communicate with each other at one of an end on the first blade height side and an end on the second blade height side; the plurality of trailing end air passages extend from a rear wing air passage, which is the blade air passage closest to the trailing edge among the plurality of blade air passages, toward the trailing edge and have trailing edge openings that open at the trailing edge, When a region of the trailing edge extending in the blade height direction that includes the end on the first blade height side and does not include the end on the second blade height side is defined as a first side region, and a region of the trailing edge that is separated from the first side region to the second blade height side and includes the end on the second blade height side is defined as a second side region, and the opening area of ​​the trailing edge openings in the plurality of trailing end air passages per unit length of the trailing edge in the blade height direction is defined as an opening ratio, an opening ratio of the trailing edge openings in the plurality of rear end air passages is higher in the first side region than in the second side region; an opening ratio of an intermediate region between the first side region and the second side region in the blade height direction at the trailing edge is higher than the opening ratio of the second side region and lower than the opening ratio of the first side region; Static wing.

2. The vane according to claim 1, the number of the trailing edge openings is greater in the first side region than in the second side region; Static wing.

3. In the vane described in claim 1, the aperture ratio of the first side region is three times or more higher than the aperture ratio of the intermediate region; Static wing.

4. The vane according to any one of claims 1 to 3, the aperture ratio of the second side region is 0; Static wing.

5. The vane according to any one of claims 1 to 3, the first side region is a region of the trailing edge extending from an end of the trailing edge on the first blade height side to the second blade height side within 25% of a length of the trailing edge in the blade height direction, The second side region is a region in the trailing edge that is within 25% of the length of the trailing edge in the blade height direction from the end of the trailing edge on the second blade height side to the first blade height side. Static wing.

6. The vane according to any one of claims 1 to 3, the number of the plurality of blade air passages is an even number; Static wing.

7. The vane according to any one of claims 1 to 3, The number of the plurality of blade air passages is two. Static wing.

8. a turbine rotor rotatable about an axis; a turbine casing that covers an outer periphery of the turbine rotor; a plurality of stator blade rows arranged in an axial direction in which the axis extends and attached to an inner peripheral side of the turbine casing; Equipped with Each of the plurality of stator blade rows has a plurality of stator blades arranged in a circumferential direction with respect to the axis, each of the plurality of stator vanes included in a final stage stator vane row that is the stator vane row located furthest downstream in the axial direction among the plurality of stator vane rows on the upstream side and the downstream side in the axial direction is the stator vane according to any one of claims 1 to 3, each of the plurality of stator vanes included in the stator vane row of the final stage is attached to the turbine casing so that the blade height direction is a radial direction with respect to the axis, the first blade height side is the radially outer side of a radially inner side and a radially outer side in the radial direction, and a side where the trailing edge is present with respect to the leading edge is a downstream side of the axis; Gas turbine.

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