Stator blade and gas turbine provided with same

Abstract

The stator blade is provided with a blade body having a blade-shaped cross-section. The blade body has an aft space and an adjacent space between the leading edge and the trailing edge, and a plurality of aft cooling channels penetrating from the aft space to the trailing edge. The adjacent space is located closer to the front edge side than the rear end space. The edge of the leading edge side of the rear end space is open and communicates with the rear end space. A plurality of partition ribs and a plurality of pins for partitioning the interior of the rear end space in the height direction of the blade are arranged in the rear end space in the height direction of the blade. Each of the plurality of pins is engaged with a positive-pressure-side inner wall surface and a negative-pressure-side inner wall surface that define the rear-end space. At least one of the plurality of partition ribs forms an extended partition rib that extends into the adjacent space and is joined to an inner wall surface defining the adjacent space.

Description

Technical Field

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

[0002] This application claims priority based on patent application No. 2022-089017 filed in Japan on May 31, 2022, and the contents are incorporated herein by reference. Background Art

[0003] The gas turbine comprises a compressor for compressing air to generate compressed air, a burner for burning fuel in the compressed air to generate combustion gas, and a turbine driven by the combustion gas. The turbine comprises a turbine rotor rotating about an axis, a turbine casing covering the rotor, and a plurality of rows of stationary blades. The turbine rotor comprises a rotor shaft centered about the axis and a plurality of rows of moving blades mounted on the rotor shaft. The plurality of rows of moving blades are arranged in the axial direction along which the axis extends. Each row of moving blades comprises a plurality of moving blades arranged in the circumferential direction relative to the axis. The plurality of rows of stationary blades are arranged in the axial direction and mounted on the inner circumference of the turbine casing. The plurality of rows of stationary blades are respectively arranged on the axial upstream side of any one of the plurality of rows of moving blades. Each row of stationary blades comprises a plurality of stationary blades arranged in the circumferential direction relative to the axis.

[0004] The stationary blade has a blade body extending in a radial direction relative to the axis and having a blade shape, an inner shroud provided radially inward of the blade body, and an outer shroud provided radially outward of the blade body. The blade body of the stationary blade is arranged in a combustion gas flow path through which the combustion gas passes. The inner shroud defines a radially inner edge of the combustion gas flow path. The outer shroud defines a radially outer edge of the combustion gas flow path.

[0005] The stationary blades of the gas turbine are exposed to high-temperature combustion gas, and therefore, are usually cooled by air or the like.

[0006] For example, a plurality of cooling air spaces through which cooling air passes are formed in the blade body of the stationary blade described in the following patent document 1. The plurality of cooling air spaces all extend in a radial direction relative to the axis, that is, in the blade height direction. A plurality of rear end cooling channels extending to the trailing edge of the blade body are formed from the rear end space closest to the trailing edge side among the plurality of cooling air spaces. A plurality of pins and a plurality of ribs that separate the rear end space in the blade height direction are arranged in the rear end space. A plurality of pins protrude from the inner surface of the positive pressure side or the inner surface of the negative pressure side that defines the rear end space. Furthermore, a plurality of ribs also protrude from the inner surface of the positive pressure side or the inner surface of the negative pressure side that defines the rear end space. Furthermore, a cylindrical insert is inserted into an adjacent space connected to the edge of the leading edge side of the rear end space among the plurality of cooling air spaces. The cylindrical insert is formed with a through hole that can eject cooling air from the inner peripheral side toward the outer peripheral side.

[0007] Furthermore, for example, a plurality of cooling air spaces through which cooling air passes are also formed in the blade body of the stationary blade described in the following patent document 2. The plurality of cooling air spaces all extend in a radial direction relative to the axis, that is, in the blade height direction. A plurality of pins are arranged in the rear end space closest to the trailing edge side of the plurality of cooling air spaces. The plurality of pins are engaged with the inner surface of the positive pressure side and the inner surface of the negative pressure side that define the rear end space. Furthermore, a cylindrical insert is inserted into an adjacent space connected to the edge of the leading edge side of the rear end space in the plurality of cooling air spaces. The cylindrical insert is formed with a through hole that can eject cooling air from the inner peripheral side toward the outer peripheral side.

[0008] Previous technical literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 10-306705, Figure 5

[0011] Patent Document 2: Japanese Patent No. 6353131 Summary of the invention

[0012] Technical issues to be solved by the invention

[0013] In the technologies described in Patent Documents 1 and 2, heat exchange between the wall defining the rear end space and the cooling air in the rear end space can be effectively performed by providing a plurality of pins in the rear end space. In addition, as in the technology described in Patent Document 2, if the inner surface on the positive pressure side and the inner surface on the negative pressure side defining the rear end space are connected by a plurality of pins in the rear end space, the rigidity of the portion including the rear end space in the stationary blade can be improved.

[0014] Furthermore, in the techniques described in Patent Documents 1 and 2, a cylindrical insert is inserted into the adjacent space connected to the edge of the front edge side of the rear end space, and therefore the inner surface on the positive pressure side and the inner surface on the negative pressure side defining the adjacent space are not connected by a pin or the like. Therefore, the rigidity of the portion around the adjacent space in the stationary blade is lower than the rigidity of the portion around the rear end space in the stationary blade.

[0015] During the operation of a gas turbine, the pressure in the cooling air space of the blade body is higher than the pressure outside the blade body. Therefore, during the operation of a gas turbine, the pressure difference between the inside and outside of the blade body exerts a force on the blade body that causes the blade surface of the blade body to expand outward. The phenomenon in which the blade surface expands due to this force causes creep deformation is called expansion.

[0016] In the blade body of the stationary blade, a portion with low rigidity is prone to swelling. If swelling occurs, not only the aerodynamic performance of the stationary blade is degraded, but also the durability of the stationary blade is degraded.

[0017] Therefore, an object of the present invention is to provide a technology capable of improving the expansion strength of a stationary blade and suppressing a decrease in the aerodynamic performance or durability of the stationary blade.

[0018] Means for solving technical problems

[0019] A stator blade according to one aspect of the invention for achieving the above object is provided in a gas turbine, and includes a blade body having a blade-shaped cross section and extending in a blade height direction having a directional component perpendicular to the cross section.

[0020] The blade body has a leading edge and a trailing edge extending in the blade height direction, a positive pressure surface and a negative pressure surface extending in the blade height direction and connecting the leading edge and the trailing edge, a rear end space and an adjacent space located between the leading edge and the trailing edge and between the positive pressure surface and the negative pressure surface, and a plurality of rear end cooling channels penetrating from the rear end space to the trailing edge. The adjacent space is located closer to the leading edge side than the rear end space. The edge of the leading edge side of the rear end space is open and communicates with the rear end space. The adjacent space and the rear end space are both defined by an inner wall surface. The inner wall surface of the adjacent space and the inner wall surface of the rear end space both have a positive pressure side inner wall surface extending along the positive pressure surface and a negative pressure side inner wall surface extending along the negative pressure surface and separated from the positive pressure side inner wall surface to the negative pressure side. The positive pressure side inner wall surface of the adjacent space is connected to the positive pressure side inner wall surface of the rear end space. The negative pressure side inner wall surface of the adjacent space is connected to the negative pressure side inner wall surface of the rear end space. A plurality of partition ribs and a plurality of pins for partitioning the rear end space in the blade height direction are arranged in the rear end space along the blade height direction.

[0021] The plurality of pins are all engaged with the inner wall surface of the positive pressure side of the rear space and the inner wall surface of the negative pressure side of the rear space. At least one of the plurality of ribs is formed as an extended rib extending into the adjacent space and engaged with the inner wall surface defining the adjacent space.

[0022] In this embodiment, the inner wall surface on the positive pressure side and the inner wall surface on the negative pressure side that define the rear end space are connected by multiple pins. Therefore, the rigidity around the rear end space in the blade body is higher than the rigidity around the adjacent space in the blade body. In other words, the rigidity around the adjacent space in the blade body is lower than the rigidity around the rear end space in the blade body. The portion with low rigidity in the blade body is prone to expansion. If this expansion phenomenon occurs, not only the aerodynamic performance of the stationary blade is reduced, but also the durability of the stationary blade is reduced. In particular, high stress is generated near the boundary between the portion with low rigidity in the blade body and the portion with high rigidity in the blade body due to deformation caused by the expansion phenomenon. That is, high stress is generated near the boundary between the adjacent space and the rear end space due to deformation caused by the expansion phenomenon.

[0023] Therefore, in this embodiment, at least one of the plurality of partition ribs disposed in the rear end space is extended into the adjacent space to increase the rigidity near the boundary between the adjacent space and the rear end space. As a result, in this embodiment, the expansion phenomenon is suppressed, thereby suppressing deformation near the boundary between the adjacent space and the rear end space.

[0024] Therefore, in this embodiment, the expansion strength of the stationary blade is improved, and it is possible to suppress a decrease in the aerodynamic performance or durability of the stationary blade due to the occurrence of the expansion phenomenon.

[0025] A gas turbine according to one aspect of the invention for achieving the above-mentioned object includes the stator blades according to the above-mentioned aspect, a rotor that rotates about an axis, and a casing that covers the outer circumference of the rotor.

[0026] The stationary blades are fixed to the inner circumferential surface of the casing.

[0027] Effects of the Invention

[0028] According to one aspect of the present invention, it is possible to improve the expansion strength of the stationary blade and suppress a decrease in the aerodynamic performance or durability of the stationary blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic cross-sectional view of a gas turbine in one embodiment according to the present invention.

[0030] Figure 2 It is a perspective view of a stationary blade in one embodiment according to the present invention.

[0031] Figure 3 is along Figure 2 Cross-sectional view taken along line ii i-iiI (longitudinal cross-sectional view of the main part of the stationary blade).

[0032] Figure 4 is along Figure 3 Cross-sectional view taken along line iV-iV in FIG. 1 (cross-sectional view of the blade body).

[0033] Figure 5 yes Figure 4 Enlarged view of the V section in (cross-sectional view of the main part of the blade body).

[0034] Figure 6 It is a longitudinal sectional view of a main part of a stationary blade in a modified example of one embodiment according to the present invention.

[0035] Figure 7 This is a cross-sectional view of a main part of a blade body in another modified example of the one embodiment according to the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of a stator blade and a gas turbine including the stator blade according to the present invention will be described in detail with reference to the drawings.

[0037] "Gas Turbine Implementation Methods"

[0038] refer to Figure 1 An embodiment of a gas turbine will be described.

[0039] like Figure 1 As shown, the gas turbine 10 of the present embodiment includes a compressor 20 for compressing air A, a combustor 30 for burning fuel F in the air A compressed by the compressor 20 to generate a combustion gas G, and a turbine 40 driven by the combustion gas G.

[0040] The compressor 20 has a compressor rotor 21 that rotates around the axis Ar, a compressor housing 25 that covers the compressor rotor 21, and a plurality of stationary blade rows 26. The turbine 40 has a turbine rotor 41 that rotates around the axis Ar, a turbine housing 45 that covers the turbine rotor 41, and a plurality of stationary blade rows 46. In addition, hereinafter, the direction in which the axis Ar extends is set as the axial direction Da, the circumferential direction centered on the axis Ar is simply set as the circumferential direction Dc, and the direction perpendicular to the axis Ar is set as the radial direction Dr. Furthermore, one side in the axial direction Da is set as the axial upstream side Dau, and the side opposite thereto is set as the axial downstream side Dad. Furthermore, in the radial direction Dr, the side close to the axis Ar is set as the radial inner side Dri, and the side opposite thereto is set as the radial outer side Dro.

[0041] The compressor 20 is arranged on the axial upstream side Dau with respect to the turbine 40 .

[0042] The compressor rotor 21 and the turbine rotor 41 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 11. For example, a rotor of a generator GEN is connected to the gas turbine rotor 11. The gas turbine 10 further includes an intermediate casing 16. The intermediate casing 16 is arranged between the compressor casing 25 and the turbine casing 45 in the axial direction Da. The compressor casing 25, the intermediate casing 16, and the turbine casing 45 are connected to each other to form a gas turbine casing 15.

[0043] The compressor rotor 21 has a rotor shaft 22 extending along the axial direction Da with the axis Ar as the center, and a plurality of moving blade rows 23 mounted on the rotor shaft 22. The plurality of moving blade rows 23 are arranged along the axial direction Da. Each moving blade row 23 is composed of a plurality of moving blades arranged along the circumferential direction Dc. Any one of the plurality of stationary blade rows 26 is arranged on the axial downstream side Dad of each of the plurality of moving blade rows 23. Each stationary blade row 26 is provided on the inner side of the compressor housing 25. Each stationary blade row 26 is composed of a plurality of stationary blades arranged along the circumferential direction Dc.

[0044] The turbine rotor 41 has a rotor shaft 42 extending along the axial direction Da with the axis Ar as the center, and a plurality of moving blade rows 43 mounted on the rotor shaft 42. The plurality of moving blade rows 43 are arranged along the axial direction Da. Each moving blade row 43 is composed of a plurality of moving blades arranged along the circumferential direction Dc. Any one of the plurality of stationary blade rows 46 is arranged on the axial upstream side Dau of each of the plurality of moving blade rows. Each stationary blade row 46 is arranged on the inner side of the turbine housing 45. Each stationary blade row 46 is composed of a plurality of stationary blades arranged along the circumferential direction Dc.

[0045] The combustor 30 is mounted on the center casing 16 .

[0046] The compressor 20 compresses air A to generate compressed air. The compressed air flows into the combustor 30. Fuel F is supplied to the combustor 30. In the combustor 30, the fuel F burns in the compressed air to generate high-temperature and high-pressure combustion gas G. The combustion gas G is delivered from the combustor 30 to the annular combustion gas flow path 49 in the turbine casing 45. The combustion gas G rotates the turbine rotor 41 while flowing toward the axial downstream side Dad in the combustion gas flow path 49. The rotation of the turbine rotor 41 rotates the rotor of the generator GEN connected to the gas turbine rotor 11. As a result, the generator GEN generates electricity.

[0047] Hereinafter, an embodiment and its modified examples related to the stationary blades constituting the primary stationary blade row 46 in the turbine 40 will be described.

[0048] "Methods of implementing stationary blades"

[0049] refer to Figure 2 to Figure 5, the implementation method of the stationary blade is described. In addition, Figure 2 It is a perspective view of the stationary blade in this embodiment. Figure 3 is along Figure 2 Cross-sectional view taken along line ii i-iiI (longitudinal cross-sectional view of the main part of the stationary blade). Figure 4 is along Figure 3 Cross-sectional view taken along line IV-IV in FIG. 1 (cross-sectional view of the blade body). Figure 5 yes Figure 4 Enlarged view of the V section in (cross-sectional view of the main part of the blade body).

[0050] like Figure 2 to Figure 4 As shown, the stationary blade 50 of the present embodiment includes a blade body 51, an inner shroud 80i, an outer shroud 80o, an inner impact plate 88i, an outer impact plate 88o, a first insert member 68A, a second insert member 68B, and a third insert member 68C.

[0051] The cross-sectional shape of the blade body 51 is a blade shape, and extends along the blade height direction Dh having a directional component perpendicular to the cross-sectional shape. The outer shroud 80o is provided at one end of the blade body 51 in the blade height direction Dh. The inner shroud 80i is provided at the other end of the blade body 51 in the blade height direction Dh. The blade body 51, the inner shroud 80i, and the outer shroud 80o are integrally formed by casting or the like.

[0052] When the stationary blade 50 is mounted on the turbine housing 45, the blade height direction Dh becomes the radial direction Dr. And one side in the blade height direction Dh, that is, the blade height first side Dh1, becomes the radial outer side Dro, and the other side in the blade height direction Dh, that is, the blade height second side Dh2, becomes the radial inner side Dri. Therefore, the outer shroud 80o is provided on the radial outer side Dro of the blade body 51, and the inner shroud 80i is provided on the radial inner side Dri of the blade body 51. Therefore, in the present embodiment, the blade height direction Dh is sometimes referred to as the radial direction Dr, the blade height first side Dh1 is referred to as the radial outer side Dro, and the blade height second side Dh2 is referred to as the radial inner side Dri.

[0053] like Figure 2 to Figure 4As shown, the outer surface of the blade body 51, i.e., the blade surface, has a leading edge 52, a trailing edge 53, a convex surface, i.e., a negative pressure surface 54, and a concave surface, i.e., a positive pressure surface 55. The negative pressure surface 54 and the positive pressure surface 55 are surfaces connecting the leading edge 52 and the trailing edge 53. The leading edge 52, the trailing edge 53, the negative pressure surface 54, and the positive pressure surface 55 all extend in the blade height direction Dh, i.e., in the radial direction Dr. When the stationary blade 50 is mounted on the turbine housing 45, the leading edge 52 is located on the axial upstream side Dau relative to the trailing edge 53. Furthermore, when the stationary blade 50 is mounted on the turbine housing 45, the negative pressure surface 54 faces one side in the circumferential direction Dc, and the positive pressure surface 55 faces the other side in the circumferential direction Dc. The blade body 51 is configured to utilize Figure 1 The combustion gas flow path 49 of the turbine 40 to be described.

[0054] The blade body 51 has a plurality of cooling air spaces 60 extending in the blade height direction Dh (radial direction Dr) inside the blade body 51. The plurality of cooling air spaces 60 are arranged from the axial upstream side Dau toward the axial downstream side Dad along the arc line CL of the blade body 51. Here, the cooling air space 60 closest to the axial upstream side Dau among the plurality of cooling air spaces 60 is set as the first space 60A, the cooling air space 60 adjacent to the axial downstream side Dad of the first space 60A is set as the second space 60B, the cooling air space 60 adjacent to the axial downstream side Dad of the second space 60B is set as the third space 60C, and the cooling air space 60 adjacent to the axial downstream side Dad of the third space 60C is set as the fourth space 60D. The first space 60A and the second space 60B are separated by a first partition wall 57 extending in a direction substantially perpendicular to the arc line CL. Furthermore, the second space 60B and the third space 60C are separated by a second partition wall 58 extending in a direction substantially perpendicular to the arc line CL. A first insert member 68A is disposed in the first space 60A, a second insert member 68B is disposed in the second space 60B, and a third insert member 68C is disposed in the third space 60C.

[0055] The inner shroud 80i defines an edge of the annular combustion gas flow path 49 on the radial inner side Dri. Also, the outer shroud 80o defines an edge of the annular combustion gas flow path 49 on the radial outer side Dro.

[0056] The inner shield 80i includes a shield body 81i, a peripheral wall 84i, and a retainer 86i.

[0057] The shield body 81i is a square plate-shaped member extending in a direction including a directional component of a direction perpendicular to the blade height direction Dh, i.e., the radial direction Dr. The shield body 81i has a gas path surface 82i and a gas path opposite surface 83i. The gas path surface 82i is a surface facing the first side Dh1 of the blade height, i.e., the radial outer side Dro, and in contact with the combustion gas G. The gas path opposite surface 83i is a surface facing the second side Dh2 of the blade height, i.e., the radial inner side Dri. The gas path opposite surface 83i and the gas path surface 82i are in a back-to-back relationship.

[0058] The peripheral wall 84i is a wall protruding from the shield body 81i toward the radial inner side Dri along the outer peripheral edge of the shield body 81i. In the inner shield 80i, a cavity 85i recessed toward the radial outer side Dro is formed by the shield body 81i and the peripheral wall 84i.

[0059] The retainer 86i is formed on the radially inner side Dri of the peripheral wall 84i. The retainer 86i is connected to the radially outer side Dro end of the inner cover (not shown) fixed to the gas turbine casing 15, and plays a role in supporting the radially inner side Dri portion of the stationary blade 50 on the inner cover.

[0060] The outer shroud 80o has basically the same structure as the inner shroud 80i. Therefore, similarly to the inner shroud 80i, the outer shroud 80o also has a shroud body 81o and a peripheral wall 84o. However, the outer shroud 80o does not have a portion corresponding to the retaining frame 86i of the inner shroud 80i. Similar to the shroud body 81i of the inner shroud 80i, the shroud body 81o of the outer shroud 80o is also a square plate-shaped component and has a gas path surface 82o and a gas path opposite surface 83o. The gas path surface 82o of the outer shroud 80o is a surface facing the second side Dh2 of the blade height, that is, the radial inner side Dri, and in contact with the combustion gas G. The gas path opposite surface 83o of the outer shroud 80o is a surface facing the first side Dh1 of the blade height, that is, the radial outer side Dro.

[0061] The peripheral wall 84o is a wall protruding from the shroud body 81o toward the radially outer side Dro along the outer peripheral edge of the shroud body 81o. In the outer shroud 80o, a cavity 85o recessed toward the radially inner side Dri is formed by the shroud body 81o and the peripheral wall 84o. A part of the peripheral wall 84o plays the role of mounting the stationary blades 50 on the inner peripheral side of the turbine housing 45.

[0062] The inner impact plate 88i partitions the cavity 85i of the inner shroud 80i into two spaces in the blade height direction Dh. A plurality of impact holes 89 penetrating in the blade height direction Dh are formed in the inner impact plate 88i.

[0063] The cooling air Ac flowing into the cavity 85i of the inner shroud 80i is ejected from the plurality of impact holes 89 of the inner impact plate 88i to the radially outer side Dro, collides with the gas path opposite surface 83i of the inner shroud 80i, and performs impact cooling on the gas path opposite surface 83i. The cooling air Ac that has performed impact cooling on the gas path opposite surface 83i is ejected into the combustion gas flow path 49 through a passage not shown, for example, to perform film cooling on the gas path surface 82i and the like.

[0064] The outer impact plate 88o divides the cavity 85o of the outer shroud 80o into two spaces in the blade height direction Dh. A plurality of impact holes 89 penetrating in the blade height direction Dh are formed in the outer impact plate 88o.

[0065] The cooling air Ac flowing into the cavity 85o of the outer shroud 80o is ejected from the plurality of impact holes 89 of the outer impact plate 88o to the radially inner side Dri and collides with the gas path opposite surface 83o of the outer shroud 80o, and is impact-cooled. The cooling air Ac that has impact-cooled the gas path opposite surface 83o is ejected to the combustion gas flow path 49 through a passage (not shown), for example, and performs film cooling on the gas path surface 82o and the like.

[0066] like Figure 3 and Figure 4 As shown, in the third space 60C, the end of the second side Dh2 of the blade height, i.e., the radial inner side Dri, is closed, and the end of the first side Dh1 of the blade height, i.e., the radial outer side Dro, is open. In addition, the end of the radial inner side Dri of the blade body 51 forms a part of the gas path opposite surface 83i of the inner shroud 80i, and the end of the radial outer side Dro of the blade body 51 forms a part of the gas path opposite surface 83o of the outer shroud 80o. Therefore, the opening 61C of the third space 60C opens on the gas path opposite surface 83o of the outer shroud 80o. A plurality of third blade surface cooling channels 67C are formed in the blade body 51, extending from the inner wall surface 62C defining the third space 60C to the blade surface of the blade body 51.

[0067] and use Figure 3 and Figure 4Similarly to the third space 60C described, the first space 60A and the second space 60B are also closed at the second side Dh2 of the blade height, i.e., the radially inner side Dri, and open at the first side Dh1 of the blade height, i.e., the radially outer side Dro. Similar to the opening 61C of the third space 60C, the opening of the first space 60A and the opening of the second space 60B are open on the opposite side 83o of the gas path of the outer shroud 80o. A plurality of first blade surface cooling passages 67A are formed in the blade body 51, penetrating from the inner wall surface 62A defining the first space 60A to the blade surface of the blade body 51. Furthermore, a plurality of second blade surface cooling passages 67B are formed in the blade body 51, penetrating from the inner wall surface 62B defining the second space 60B to the blade surface of the blade body 51.

[0068] like Figure 3 and Figure 4 As shown, the third insert 68C disposed in the third space 60C is cylindrical and extends in the radial direction Dr. The end of the third insert 68C on the radial inner side Dri is closed, and the end of the third insert 68C on the radial outer side Dro is open. The third insert 68C is substantially entirely located in the third space 60C, but the portion of the third insert 68C on the radial outer side Dro protrudes from the third space 60C to the radial outer side Dro, and the end of the third insert 68C on the radial outer side Dro is located at a position closer to the radial outer side Dro than the outer impact plate 88o. Therefore, cooling air Ac can flow into the third insert 68C from the opening of the third insert 68C. A plurality of impact holes 69 penetrating from the inner circumference to the outer circumference is formed in the cylindrical third insert 68C. Therefore, the cooling air Ac flowing into the third insert 68C is ejected from the plurality of impact holes 69 and collides with the inner wall surface 62C defining the third space 60C, and is impact-cooled. A portion of the cooling air Ac that has impingement-cooled the inner wall surface 62C defining the third space 60C is ejected toward the combustion gas flow path 49 through the aforementioned plurality of third blade surface cooling passages 67C to film-cool the blade surface.

[0069] The first insert 68A disposed in the first space 60A and the second insert 68B disposed in the second space 60B are connected to the first space 60A. Figure 3 and Figure 4The structure of the third insert 68C described is substantially the same structure. That is, similarly to the third insert 68C, the first insert 68A and the second insert 68B are cylindrical and extend in the radial direction Dr. The ends of the radial inner side Dri of the first insert 68A and the second insert 68B are closed, and the ends of the radial outer side Dro of the first insert 68A and the second insert 68B are open. The first insert 68A is substantially entirely located in the first space 60A, but the portion of the radial outer side Dro of the first insert 68A protrudes from the third space 60C to the radial outer side Dro, and the end of the radial outer side Dro of the first insert 68A is located at a position closer to the radial outer side Dro than the outer impact plate 88o. Therefore, cooling air Ac can flow into the first insert 68A from the opening of the first insert 68A. A plurality of impact holes 69 penetrating from the inner circumference to the outer circumference are also formed in the cylindrical first insert 68A. Therefore, the cooling air Ac flowing into the first insert 68A is ejected from the plurality of impact holes 69 and collides with the inner wall surface 62A defining the first space 60A, and is impact-cooled. The cooling air Ac that has impact-cooled the inner wall surface 62A defining the first space 60A is ejected toward the combustion gas flow path 49 through the plurality of first blade surface cooling passages 67A described above, and performs film cooling on the blade surface. In addition, the second insert 68B is substantially entirely located in the second space 60B, but the radially outer side Dro portion of the second insert 68B protrudes from the second space 60B to the radially outer side Dro, and the end of the radially outer side Dro of the second insert 68B is located at a position closer to the radially outer side Dro than the outer impact plate 88o. Therefore, the cooling air Ac can flow into the second insert 68B from the opening of the second insert 68B. A plurality of impact holes 69 penetrating from the inner circumference to the outer circumference are also formed in the cylindrical second insert 68B. Therefore, the cooling air Ac flowing into the second insert 68B is ejected from the plurality of impact holes 69 and collides with the inner wall surface 62B defining the second space 60B, thereby performing impact cooling on the inner wall surface 62B defining the second space 60B. The cooling air Ac that has performed impact cooling on the inner wall surface 62B defining the second space 60B is ejected toward the combustion gas flow path 49 through the plurality of second blade surface cooling passages 67B described above, thereby performing film cooling on the blade surface.

[0070] Among the plurality of cooling air spaces 60, the fourth space 60D is located closest to the downstream side Dad of the axis. Therefore, hereinafter, the fourth space 60D is referred to as the rear end space 60D. Furthermore, the third space 60C is adjacent to the upstream side Dau of the axis of the rear end space 60D. Therefore, hereinafter, the third space 60C is referred to as the adjacent space 60C.

[0071] The end of the second side Dh2 at the blade height, i.e., the radially inner side Dri, and the end of the first side Dh1 at the blade height, i.e., the radially outer side Dro of the rear end space 60D are closed. Furthermore, the edge of the axial upstream side Dau of the rear end space 60D (the edge on the leading edge 52 side) is open and connected to the adjacent space 60C. The inner wall surface 62D defining the rear end space 60D has an inner wall surface 64D at the first side at the blade height, an inner wall surface 65D at the second side at the blade height, an inner wall surface 63Dp at the positive pressure side, and an inner wall surface 63Dn at the negative pressure side. The inner wall surface 64D at the first side at the blade height faces the second side Dh2 at the blade height, and defines the edge of the first side Dh1 at the blade height of the rear end space 60D. The inner wall surface 65D at the second side at the blade height faces the first side Dh1 at the blade height, and defines the edge of the second side Dh2 at the blade height of the rear end space 60D. The positive pressure side inner wall surface 63Dp faces the negative pressure surface 54 side, and extends along the positive pressure surface 55 to define the edge of the positive pressure surface 55 side of the rear end space 60D. The edge of the positive pressure side inner wall surface 63Dp on the blade height first side Dh1 is connected to the blade height first side inner wall surface 64D. In addition, the edge of the positive pressure side inner wall surface 63Dp on the blade height second side Dh2 is connected to the blade height second side inner wall surface 65D. The negative pressure side inner wall surface 63Dn faces the positive pressure surface 55 side, and extends along the negative pressure surface 54 and separates from the positive pressure side inner wall surface 63Dp to the negative pressure surface 54 side to define the edge of the negative pressure surface 54 side of the rear end space 60D. The edge of the negative pressure side inner wall surface 63Dn on the blade height first side Dh1 is connected to the blade height first side inner wall surface 64D. In addition, the edge of the negative pressure side inner wall surface 63Dn on the blade height second side Dh2 is connected to the blade height second side inner wall surface 65D. Furthermore, an edge of the negative-pressure inner wall surface 63Dn on the downstream side Dad of the axis line is connected to an edge of the positive-pressure inner wall surface 63Dp on the downstream side Dad of the axis line.

[0072] A plurality of rear cooling passages 67D penetrating from the rear end space 60D to the combustion gas flow path are formed in the blade body 51. The rear cooling passages 67D penetrate from the boundary line between the edge of the negative pressure side inner wall surface 63Dn on the axial downstream side Dad and the edge of the positive pressure side inner wall surface 63Dp on the axial downstream side Dad to the trailing edge 53 of the blade body 51. The plurality of rear cooling passages 67D are arranged along the blade height direction Dh.

[0073] Arranged in the rear end space 60D are a plurality of partition ribs 71 and a plurality of cylindrical or polygonal pins 72 which are arranged in the blade height direction Dh and partition the rear end space 60D in the blade height direction Dh.

[0074] The plurality of partition ribs 71 extend in a direction substantially perpendicular to the blade height direction Dh and engage with the positive pressure side inner wall surface 63Dp and the negative pressure side inner wall surface 63Dn. The plurality of pins 72 extend in a direction substantially perpendicular to the arc line CL and engage with the positive pressure side inner wall surface 63Dp and the negative pressure side inner wall surface 63Dn.

[0075] At least one of the plurality of partition ribs 71 forms an extended partition rib 71a extending into the adjacent space 60C. Specifically, the extended partition rib 71a is disposed at a position that is 30 to 70% of the dimension of the rear end space 60D in the blade height direction Dh from the blade height second side inner wall surface 65D that defines the rear end space 60D. That is, the extended partition rib 71a is disposed near the center of the blade body 51 in the blade height direction Dh.

[0076] The inner wall surface 62C defining the third space 60C, i.e., the adjacent space 60C, includes a second-side inner wall surface 65C at blade height, a positive-pressure inner wall surface 63Cp, a negative-pressure inner wall surface 63Cn, and a surface facing the axial downstream side Dad of the second partition wall 58, i.e., the second partition wall surface 66C. The second-side inner wall surface 65C at blade height faces the first side Dh1 at blade height, and defines an edge at the second-side Dh2 at blade height of the adjacent space 60C. The edge at the axial downstream side Dad of the second-side inner wall surface 65C at blade height is connected to the edge at the axial upstream side Dau of the second-side inner wall surface 65D at blade height that defines the rear end space 60D. The positive-pressure inner wall surface 63Cp faces the negative-pressure surface 54 side, and extends along the positive-pressure surface 55 to define an edge at the positive-pressure surface 55 side of the rear end space 60D. The edge at the second-side Dh2 at blade height of the positive-pressure inner wall surface 63Cp at blade height is connected to the second-side inner wall surface 65C at blade height. The edge of the axial upstream side Dau of the positive pressure side inner wall surface 63Cp is connected to the second partition wall surface 66C. The edge of the axial downstream side Dad of the positive pressure side inner wall surface 63Cp is connected to the edge of the axial upstream side Dau of the positive pressure side inner wall surface 63Dp that defines the rear end space 60D. The negative pressure side inner wall surface 63Cn faces the positive pressure surface 55 side, and extends along the negative pressure surface 54 surface and separates from the positive pressure side inner wall surface 63Cp to the negative pressure surface 54 side to define the edge of the negative pressure surface 54 side of the adjacent space 60C. The edge of the blade height second side Dh2 of the negative pressure side inner wall surface 63Cn is connected to the blade height second side inner wall surface 65C. The edge of the axial upstream side Dau of the negative pressure side inner wall surface 63Cn is connected to the second partition wall surface 66C. The edge of the negative pressure side inner wall surface 63Cn on the downstream side of the axis Dad is connected to the edge of the negative pressure side inner wall surface 63Dn on the upstream side of the axis Dau that defines the rear end space 60D.

[0077] The portion of the extended rib 71a existing in the adjacent space 60C is joined to the positive pressure side inner wall surface 63Dp and the negative pressure side inner wall surface 63Cn of the inner wall surface 62C defining the adjacent space 60C. Figure 5 As shown, the extension dimension L of the extended partition rib 71a extending from the edge (edge ​​on the front edge 52 side) on the axial upstream side Dau of the rear end space 60D in the adjacent space 60C is less than twice the interval between the positive pressure side inner wall surface 63Dp and the negative pressure side inner wall surface 63Dn in the edge on the front edge 52 side in the rear end space 60D, that is, the boundary width W. In addition, the edge on the front edge 52 side in the rear end space 60D is the boundary between the adjacent space 60C and the rear end space 60D, and is the opening 61D on the front edge 52 side in the rear end space 60D. And, in the present embodiment, the edge on the front edge 52 side in the rear end space 60D is the position of the edge on the front edge 52 side of the pin 72 closest to the front edge 52 side among the plurality of pins 72.

[0078] The other part of the cooling air Ac ejected from the third insert 68C disposed in the third space 60C, i.e., the adjacent space 60C, and subjected to impact cooling on the inner wall surface 62C defining the adjacent space 60C, flows into the rear end space 60D from the opening 61D of the rear end space 60D. The cooling air Ac that flows into the rear end space 60D performs convection cooling on the plurality of partition ribs 71, the plurality of pins 72, and the inner wall surface 62D defining the rear end space 60D while flowing in the rear end space 60D. The cooling air Ac flows into the plurality of rear end cooling passages 67D. The cooling air Ac that flows into the rear end cooling passage 67D performs convection cooling on the surface defining the rear end space 60D while flowing in the rear end space 60D. The cooling air Ac ejected from the trailing edge 53 of the blade body 51 toward the combustion gas flow path 49.

[0079] As described above, the positive-pressure side inner wall surface 63Dp and the negative-pressure side inner wall surface 63Dn that define the rear end space 60D are joined by a plurality of pins 72 and partition ribs 71. On the other hand, a third insert 68C is inserted into the adjacent space 60C adjacent to the rear end space 60D, and therefore the positive-pressure side inner wall surface 63Cp and the negative-pressure side inner wall surface 63Cn that define the adjacent space 60C are not joined by pins or the like. Therefore, the rigidity around the adjacent space 60C in the blade body 51 is lower than the rigidity around the rear end space 60D in the blade body 51. As described in the "Technical Issues to be Solved by the Invention" column, during the operation of the gas turbine, a portion of the blade body 51 with low rigidity is prone to creep deformation in the form of blade surface expansion due to the pressure difference between the inside and outside of the blade body 51. If an expansion phenomenon occurs, the blade surface of the portion with low rigidity will be deformed as follows. Figure 4The stator blade 50 is deformed as shown by the double-dotted dashed line in the figure. If this expansion phenomenon occurs, not only the aerodynamic performance of the stator blade 50 is reduced, but also the durability of the stator blade 50 is reduced. In particular, high stress is generated near the boundary between the portion with low rigidity in the blade body 51 and the portion with high rigidity in the blade body 51 due to the deformation caused by the expansion phenomenon. That is, high stress is generated near the boundary between the adjacent space 60C and the rear end space 60D due to the deformation caused by the expansion phenomenon. Moreover, the amount of deformation caused by the expansion phenomenon becomes larger around the adjacent space 60C in the blade body 51 and near the central portion of the blade body 51 in the blade height direction Dh.

[0080] Therefore, in the present embodiment, among the plurality of partition ribs 71 disposed in the rear end space 60D, the plurality of partition ribs 71 disposed near the central portion in the blade height direction Dh of the blade body 51 are extended into the adjacent space 60C to increase the rigidity near the boundary between the adjacent space 60C and the rear end space 60D and near the central portion in the blade height direction Dh of the blade body 51. As a result, in the present embodiment, the expansion phenomenon is suppressed, thereby suppressing deformation near the boundary between the adjacent space 60C and the rear end space 60D and near the central portion in the blade height direction Dh of the blade body 51.

[0081] Therefore, in the present embodiment, the expansion strength of the stationary blade 50 is improved, and it is possible to suppress a decrease in the aerodynamic performance or durability of the stationary blade 50 due to the occurrence of the expansion phenomenon.

[0082] In the present embodiment, as described above, the extension dimension L of the extended partition rib 71a extending from the edge on the front edge 52 side of the rear end space 60D in the adjacent space 60C is smaller than the interval between the inner wall surface 63Dp on the positive pressure side of the rear end space 60D and the inner wall surface 63Dn on the negative pressure side of the rear end space 60D at the edge on the front edge 52 side of the rear end space 60D, that is, twice the boundary width W. However, the extension dimension L of the extended partition rib 71a may be larger than twice the boundary width W. In this case, compared with the case where the extension dimension L of the extended partition rib 71a is set to twice the boundary width W, although the expansion strength of the blade body 51 is increased, the increase in expansion strength is small compared to the increase in the extension dimension L. In addition, the stationary blade 50 is formed by casting, so if the extension dimension L of the extended partition rib 71a is increased, casting becomes difficult accordingly. Therefore, in the present embodiment, the extension dimension L of the extended partition rib 71a is set to be smaller than twice the boundary width W.

[0083] "First Modification of Stationary Blades"

[0084] refer to Figure 6 , a first modified example of the implementation of the stationary blade is described.

[0085] If using Figure 3As described above, in the stationary blade 50 in the embodiment, the plurality of partition ribs 71 arranged at a position of 30 to 70% of the dimension of the rear end space 60D in the blade height direction Dh from the second side inner wall surface 65D that defines the rear end space 60D form an extended partition rib 71a.

[0086] like Figure 6 As shown, in the stationary blade 50a of this modification, the plurality of partition ribs 71 are all formed as extended partition ribs 71a. Therefore, in this modification, the overall rigidity of the blade body 51 in the blade height direction Dh near the boundary between the adjacent space 60C and the rear end space 60D can be improved.

[0087] "Second modification of stationary blade"

[0088] refer to Figure 7 , a second modified example of the implementation of the stationary blade is described.

[0089] If using Figure 5 As described above, in the stationary blade 50 in the above embodiment, the portion of the extended partition rib 71 a that is present in the adjacent space 60C is joined to the pressure-side inner wall surface 63Cp and the suction-side inner wall surface 63Cn of the inner wall surface 62C that defines the adjacent space 60C.

[0090] like Figure 7 As shown, in the stationary blade 50b in this modified example, the portion of the extended partition rib 71b that exists in the adjacent space 60C is connected only to the negative pressure side inner wall surface 63Cn of the inner wall surface 62C that defines the adjacent space 60C, and is not connected to the positive pressure side inner wall surface 63Cp.

[0091] The static pressure received by the positive pressure side inner wall surface 63Cp defining the adjacent space 60C from the adjacent space 60C and the static pressure received by the negative pressure side inner wall surface 63Cn defining the adjacent space 60C from the adjacent space 60C are the same value. On the other hand, the flow velocity of the combustion gas G flowing along the negative pressure surface 54 outside the blade body 51 is higher than the flow velocity of the combustion gas G flowing along the positive pressure surface 55 outside the blade body 51, so the static pressure received by the negative pressure surface 54 from the outside of the blade body 51 is lower than the static pressure received by the positive pressure surface 55 from the outside of the blade body 51. Therefore, the pressure difference between the pressure in the adjacent space 60C and the pressure in the area outside the blade body 51 along the negative pressure surface 54 becomes larger than the pressure difference between the pressure in the adjacent space 60C and the pressure in the area outside the blade body 51 along the positive pressure surface 55. Therefore, even if an expansion phenomenon occurs around the adjacent space 60C, the amount of deformation caused by the expansion phenomenon is larger on the negative pressure surface 54 side than on the positive pressure surface 55 side.

[0092] Therefore, in this variation, the portion of the extended partition rib 71b that exists in the adjacent space 60C is joined only to the negative pressure side inner wall surface 63Cn of the inner wall surface 62C that defines the adjacent space 60C, thereby increasing the rigidity near the boundary line between the adjacent space 60C and the rear end space 60D and only on the negative pressure surface 54 side.

[0093] In this modification, since the space occupied by the extended rib 71b in the adjacent space 60C is smaller than that in the above embodiment, the insertability of the third insert member 68C into the adjacent space 60C and the degree of freedom in the layout of the third insert member 68C in the adjacent space 60C can be improved.

[0094] In addition, this modification is a modification of the stationary blade 50 in the above-mentioned embodiment. However, this modification can be applied to the stationary blade 50a in the above-mentioned first modification.

[0095] "Other modification examples of stationary blades"

[0096] The stationary blades 50, 50a, 50b in the above embodiment and each modified example all have four spaces from the first space 60A to the fourth space 60D. However, the stationary blades may also have more spaces. In addition, the stationary blades 50, 50a, 50b in the above embodiment and each modified example all have inserts in all spaces except the fourth space 60D, i.e., the rear end space 60D. However, the inserts may not be arranged in all spaces except the rear end space 60D.

[0097] The stationary blades 50, 50a, 50b in the above embodiment and each modified example are stationary blades constituting the primary stationary blade row 46. However, the stationary blades may be stationary blades constituting the stationary blade row 46 on the axial downstream side Dad of the primary stationary blade row 46.

[0098] Furthermore, the present invention is not limited to the above-described embodiment and modifications.

[0099] Various additions, changes, substitutions, partial deletions, etc. may be made without departing from the conceptual idea and gist of the present invention derived from the contents specified in the claims and their equivalents.

[0100] "P.S."

[0101] The stationary blades in the above-mentioned embodiment and each modified example can be understood, for example, as follows.

[0102] (1) The stator blades in the first embodiment are provided in the gas turbine 10. The stator blades 50, 50a, 50b include a blade body 51 having a blade-shaped cross section and extending in a blade height direction Dh having a directional component perpendicular to the cross section.

[0103] The blade body 51 has a leading edge 52 and a trailing edge 53 extending in the blade height direction Dh, a positive pressure surface 55 and a negative pressure surface 54 extending in the blade height direction Dh and connecting the leading edge 52 and the trailing edge 53, a rear end space 60D and an adjacent space 60C located between the leading edge 52 and the trailing edge 53 and between the positive pressure surface 55 and the negative pressure surface 54, and a plurality of rear end cooling passages 67D penetrating from the rear end space 60D to the trailing edge 53. The adjacent space 60C is located closer to the leading edge 52 than the rear end space 60D. The edge of the rear end space 60D on the leading edge 52 side is open and communicates with the rear end space 60D. The adjacent space 60C and the rear end space 60D are both defined by inner wall surfaces 62C and 62D. The inner wall surface 62C of the adjacent space 60C and the inner wall surface 62D of the rear end space 60D both have positive pressure side inner wall surfaces 63Cp and 63Dp extending along the positive pressure surface 55 and negative pressure side inner wall surfaces 63Cn and 63Dn extending along the negative pressure surface 54 and separated from the positive pressure side inner wall surfaces 63Cp and 63Dp toward the negative pressure surface 54. The positive pressure side inner wall surface 63Cp of the adjacent space 60C is connected to the positive pressure side inner wall surface 63Dp of the rear end space 60D. The negative pressure side inner wall surface 63Cn of the adjacent space 60C is connected to the negative pressure side inner wall surface 63Dn of the rear end space 60D. A plurality of partition ribs 71 and a plurality of pins 72 are arranged in the rear end space 60D along the blade height direction Dh to partition the rear end space 60D in the blade height direction Dh. The plurality of pins 72 are all engaged with the positive pressure side inner wall surface 63Dp of the rear end space 60D and the negative pressure side inner wall surface 63Dn of the rear end space 60D. At least one of the plurality of partition ribs 71 forms an extended partition rib 71a, 71b extending into the adjacent space 60C and engaging with the inner wall surface 62C defining the adjacent space 60C.

[0104] In this embodiment, the inner wall surface 63Dp on the positive pressure side and the inner wall surface 63Dn on the negative pressure side that define the rear end space 60D are joined by a plurality of pins 72. Therefore, the rigidity around the rear end space 60D in the blade body 51 is higher than the rigidity around the adjacent space 60C in the blade body 51. In other words, the rigidity around the adjacent space 60C in the blade body 51 is lower than the rigidity around the rear end space 60D in the blade body 51. The portion with low rigidity in the blade body 51 is prone to expansion. If this expansion occurs, not only the aerodynamic performance of the stationary blade 50 is reduced, but also the durability of the stationary blade 50 is reduced. In particular, high stress is generated near the boundary between the portion with low rigidity in the blade body 51 and the portion with high rigidity in the blade body 51 due to deformation caused by the expansion phenomenon. That is, high stress is generated near the boundary between the adjacent space 60C and the rear end space 60D due to deformation caused by the expansion phenomenon.

[0105] Therefore, in this embodiment, at least one of the plurality of partition ribs 71 disposed in the rear end space 60D is extended into the adjacent space 60C to increase the rigidity near the boundary between the adjacent space 60C and the rear end space 60D. As a result, in this embodiment, the expansion phenomenon is suppressed, thereby suppressing deformation near the boundary between the adjacent space 60C and the rear end space 60D.

[0106] Therefore, in this embodiment, the expansion strength of the stationary blades 50, 50a, 50b is improved, and it is possible to suppress a decrease in the aerodynamic performance or durability of the stationary blades 50, 50a, 50b due to the occurrence of the expansion phenomenon.

[0107] (2) Stationary blade in second aspect In the stationary blade 50 described in the first aspect, the extended partition rib 71a is arranged at a position that is 30 to 70% of the dimension of the rear end space 60D in the blade height direction Dh from one end of the rear end space 60D in the blade height direction Dh.

[0108] The amount of deformation caused by the expansion phenomenon increases around the adjacent space 60C in the blade body 51 and near the central portion of the blade body 51 in the blade height direction Dh. Therefore, in this embodiment, the partition ribs 71 arranged at a position of 30 to 70% of the dimension of the rear end space 60D in the blade height direction Dh from one end of the rear end space 60D in the blade height direction Dh among the plurality of partition ribs 71, in other words, the partition ribs 71 arranged in the central portion in the blade height direction Dh in the blade body 51 are set as extended partition ribs 71a. As a result, in this embodiment, deformation near the boundary between the adjacent space 60C and the rear end space 60D and near the central portion in the blade height direction Dh of the blade body 51 can be suppressed.

[0109] (3) Stationary Blade in Third Aspect In the stationary blade 50a in the first aspect or the second aspect, the plurality of partition ribs 71 are all the extended partition ribs 71a, 71b.

[0110] In this embodiment, the overall rigidity of the blade body 51 in the blade height direction Dh near the boundary between the adjacent space 60C and the rear end space 60D can be improved.

[0111] (4) In the stationary blades 50, 50a, 50b in any one of the first to third modes, the extension dimension L of the extended partition ribs 71a, 71b extending from the edge on the side of the leading edge 52 of the rear end space 60D in the adjacent space 60C is smaller than the interval between the positive pressure side inner wall surface 63Dp and the negative pressure side inner wall surface 63Dn in the edge on the side of the leading edge 52 in the rear end space 60D, that is, twice the boundary width W.

[0112] The extension dimension L of the extended partition ribs 71a and 71b may be greater than twice the boundary width W. In this case, compared with the case where the extension dimension L of the extended partition ribs 71a and 71b is set to twice the boundary width W, although the expansion strength of the blade body 51 increases, the increase in expansion strength is small compared to the increase in the extension dimension L. In addition, the stationary blades 50, 50a, and 50b are formed by casting, so if the extension dimension L of the extended partition ribs 71a and 71b is increased, casting becomes difficult accordingly. Therefore, in this method, the increase in expansion strength and the difficulty of casting are compared and considered, and the extension dimension L of the extended partition ribs 71a and 71b is made less than twice the boundary width W.

[0113] (5) Stationary blade in fifth aspect In the stationary blade 50b in any one of the first to fourth aspects, the extended partition rib 71b is joined to the negative pressure side inner wall surface 63Dn of the adjacent space 60C, but is not joined to the positive pressure side inner wall surface 63Dp of the adjacent space 60C.

[0114] The static pressure received by the positive pressure side inner wall surface 63Cp defining the adjacent space 60C from the adjacent space 60C and the static pressure received by the negative pressure side inner wall surface 63Cn defining the adjacent space 60C from the adjacent space 60C are the same value. On the other hand, the flow velocity of the combustion gas G flowing along the negative pressure surface 54 outside the blade body 51 is higher than the flow velocity of the combustion gas G flowing along the positive pressure surface 55 outside the blade body 51, so the static pressure received by the negative pressure surface 54 from the outside of the blade body 51 is lower than the static pressure received by the positive pressure surface 55 from the outside of the blade body 51. Therefore, the pressure difference between the pressure in the adjacent space 60C and the pressure in the area outside the blade body 51 along the negative pressure surface 54 becomes larger than the pressure difference between the pressure in the adjacent space 60C and the pressure in the area outside the blade body 51 along the positive pressure surface 55. Therefore, even if an expansion phenomenon occurs around the adjacent space 60C, the amount of deformation caused by the expansion phenomenon is larger on the negative pressure surface 54 side than on the positive pressure surface 55 side.

[0115] Therefore, in the present embodiment, the portion of the extended partition rib 71b that exists in the adjacent space 60C is joined only to the negative pressure side inner wall surface 63Cn of the inner wall surface 62C that defines the adjacent space 60C, thereby increasing the rigidity near the boundary line between the adjacent space 60C and the rear end space 60D and only on the negative pressure surface 54 side.

[0116] (6) A stationary blade in a sixth aspect is the stationary blade 50 , 50 a , 50 b in any one of the first to fifth aspects, further comprising a cylindrical insert 68C disposed in the adjacent space 60C.

[0117] A plurality of impact holes 69 penetrating from the inner peripheral side to the outer peripheral side are formed in the insert member 68C.

[0118] In this embodiment, the cooling air Ac that has flowed into the insert member 68C is ejected from the impact holes 69 and collides with the inner wall surface 62C that defines the adjacent space 60C, thereby performing impact cooling.

[0119] Therefore, in this embodiment, the blade surface along the inner wall surface 62C that defines the adjacent space 60C can be cooled effectively.

[0120] The gas turbine in the above embodiment can be understood, for example, as follows.

[0121] (7) A gas turbine according to a seventh aspect comprises:

[0122] The stationary blades 50, 50a, 50b in any one of the first to sixth aspects include a rotor 41 that rotates around the axis Ar and a casing 45 that covers the outer circumference of the rotor 41. The stationary blades 50, 50a, 50b are fixed to the inner circumference of the casing 45.

[0123] Industrial Applicability

[0124] According to one aspect of the present invention, it is possible to improve the expansion strength of the stationary blade and suppress a decrease in the aerodynamic performance or durability of the stationary blade.

[0125] Explanation of symbols

[0126] 10-gas turbine, 11-gas turbine rotor, 15-gas turbine casing, 16-intermediate casing, 20-compressor, 21-compressor rotor, 22-rotor shaft, 23-moving blade row, 25-compressor casing, 26-stationary blade row, 30-combustor, 40-turbine, 41-turbine rotor, 42-rotor shaft, 43-moving blade row, 45-turbine casing, 46-stationary blade row, 49-combustion gas flow path, 50, 50a, 50b-stationary blade, 51-blade body, 52-leading edge, 53-trailing edge, 54-negative pressure surface, 55-positive pressure surface, 57- First partition wall, 58-second partition wall, 60-cooling air space, 60A-first space, 62A-inner wall, 67A-first blade cooling channel, 68A-first insert, 69-impact hole, 60B-second space, 62B-inner wall, 67B-second blade cooling channel, 68B-second insert, 60C-third space (adjacent space), 61C-opening, 62C-inner wall, 63Cp-positive pressure side inner wall, 63Cn-negative pressure side inner wall, 65C-blade height second side inner wall, 66C-second partition wall, 67C-third blade Surface cooling channel, 68C-third insert, 60D-fourth space (rear end space), 61D-opening, 62D-inner wall surface, 63Dp-positive pressure side inner wall surface, 63Dn-negative pressure side inner wall surface, 64D-blade height first side inner wall surface, 65D-blade height second side inner wall surface, 67D-rear end cooling channel, 71-partition rib, 71a, 71b-extended partition rib, 72-pin, 80i-inner shroud, 80o-outer shroud, 81i, 81o-shroud body, 82i, 82o-gas path surface, 83i, 83o-gas path opposite surface, 8 4i, 84o- circumferential wall, 85i, 85o- cavity, 86i- retaining frame, 88i- inner impact plate, 88o- outer impact plate, 89- impact hole, A- air, Ac- cooling air, F- fuel, G- combustion gas, Ar- axis, CL- arc line, Da- axial direction, Dau- upstream side of the axis, Dad- downstream side of the axis, Dc- circumferential direction, Dr- radial direction, Dri- radial inner side, Dro- radial outer side, Dh- blade height direction, Dh1- first side of blade height, Dh2- second side of blade height, L- extension dimension, W- boundary width.

Claims

1. A stationary blade provided in a gas turbine, the stationary blade comprising: The blade body has a blade-shaped cross section and extends in a blade height direction having a directional component perpendicular to the cross section. The blade body comprises a leading edge and a trailing edge extending in the blade height direction, a positive pressure surface and a negative pressure surface extending in the blade height direction and connecting the leading edge and the trailing edge, a rear end space and an adjacent space located between the leading edge and the trailing edge and between the positive pressure surface and the negative pressure surface, and a plurality of rear end cooling channels penetrating from the rear end space to the trailing edge, The adjacent space is located closer to the front edge than the rear end space. The edge of the front edge side of the rear end space is open and communicates with the rear end space. The adjacent space and the rear space are both defined by the inner wall surface. The inner wall surface of the adjacent space and the inner wall surface of the rear end space both have a positive pressure side inner wall surface extending along the positive pressure surface and a negative pressure side inner wall surface extending along the negative pressure surface and separated from the positive pressure side inner wall surface toward the negative pressure side. The inner wall surface of the positive pressure side of the adjacent space is connected to the inner wall surface of the positive pressure side of the rear end space, The negative pressure side inner wall surface of the adjacent space is connected to the negative pressure side inner wall surface of the rear end space, In the rear end space, a plurality of partition ribs and a plurality of pins are arranged along the blade height direction to partition the rear end space in the blade height direction. The plurality of pins are engaged with the inner wall surface on the positive pressure side of the rear end space and the inner wall surface on the negative pressure side of the rear end space, At least one of the plurality of ribs is formed as an extended rib extending into the adjacent space and engaging with the inner wall surface defining the adjacent space.

2. The stationary blade according to claim 1, in, The extended rib is disposed at a position that is 30 to 70% of a dimension of the rear end space in the blade height direction from one end of the rear end space in the blade height direction.

3. The stationary blade according to claim 1 or 2, in, The plurality of ribs are all the extended ribs.

4. The stationary blade according to claim 1 or 2, in, The extended dimension of the extended partition rib extending from the edge of the leading edge side of the rear end space in the adjacent space is smaller than twice the distance between the positive pressure side inner wall surface and the negative pressure side inner wall surface in the edge of the leading edge side in the rear end space, i.e., the boundary width.

5. The stationary blade according to claim 1 or 2, in, The extended rib is joined to the negative pressure side inner wall surface of the adjacent space, but is not joined to the positive pressure side inner wall surface of the adjacent space.

6. The stationary blade according to claim 1 or 2, further comprising: A cylindrical insert is disposed in the adjacent space. A plurality of impact holes penetrating from the inner peripheral side to the outer peripheral side are formed in the insert member.

7. A gas turbine comprising: The stationary blade according to claim 1 or 2; a rotor, which rotates about an axis; and a housing covering an outer peripheral side of the rotor, The stationary blades are fixed to the inner circumferential surface of the casing.

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