Flow passage forming plate, stationary blade, and gas turbine

Abstract

This flow passage forming plate includes a gas path surface, a rear end surface, a cavity into which cooling air can flow, and a cooling air passage through which the cooling air flowing into the cavity can flow. The cooling air passage has a plurality of rear end jetting passages arranged in the lateral direction and opening on the rear-end face. The plurality of rear end jetting passages have a plurality of rear-end jetting small passages and a plurality of rear-end jetting large passages. Some of the plurality of rear-end jetting large passages are positioned adjacent to each other in the lateral direction on the first-most side in the lateral direction and the second-most side in the lateral direction. The passage cross-sectional area of each of the plurality of rear-end jetting large passages is greater than the passage cross-sectional area of any of the plurality of rear-end jetting small passages.

Description

Flow path forming plate, stationary blade, and gas turbine

[0001] This application claims priority to Japanese Patent Application No. 2023-197379, filed on November 21, 2023, the contents of which are incorporated herein by reference.

[0002] A gas turbine includes a turbine rotor that rotates about an axis, a plurality of stator vanes, a plurality of ring segments, and a turbine casing that covers them. The rotor has a rotor shaft and a plurality of blade rows attached to the rotor shaft. The blade rows are aligned in the axial direction along which the axis extends. Each of the blade rows has a plurality of blades aligned in the circumferential direction about the axis. Furthermore, a plurality of stator vane rows are provided inside the turbine casing. One of the blade rows is arranged axially upstream of each of the blade rows. Each of the blade rows has a plurality of blades aligned in the circumferential direction. A plurality of ring segments are arranged in the portions between the blade rows in the axial direction, i.e., in the portions where one of the blade rows is present in the axial direction.

[0003] The stator vane has a blade body that extends radially relative to the axis and forms an airfoil shape, 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 a portion of the radially inner edge of the combustion gas flow path. The outer shroud defines a portion of the radially outer edge of the combustion gas flow path. Furthermore, the segmented ring defines a portion of the radially outer edge of the combustion gas flow path. Therefore, the inner shroud of the stator vane, the outer shroud of the stator vane, and the segmented ring are flow path forming plates that have gas path surfaces that define a portion of the combustion gas flow path and side surfaces that are connected to the edges of the gas path surfaces.

[0004] The flow passage forming plate described above is exposed to high-temperature combustion gas, and therefore is generally cooled by air or the like.

[0005] For example, a gas turbine passage forming plate described in Patent Document 1 below has a plurality of cooling air passages through which cooling air can flow. Some of the plurality of cooling air passages are ejection passages that open on a side surface of the passage forming plate.

[0006] Japanese Patent Application Laid-Open No. 2008-138666

[0007] The cooling air flowing through the cooling air passage generally contains small amounts of foreign matter, such as metal powder and dust. Therefore, if the inner diameter of the multiple jet passages is reduced, foreign matter may become lodged in one of the multiple jet passages. In this case, the cooling effect of the passage-forming plate near the passage with the lodged foreign matter may decrease, potentially causing thermal damage to the passage-forming plate within a short period of time. Conversely, if the inner diameter of the multiple jet passages is increased, the flow rate of cooling air supplied to the passage-forming plate increases, resulting in a decrease in gas turbine efficiency.

[0008] Therefore, an object of the present disclosure is to provide a flow passage forming plate, a stator blade, and a gas turbine that can reduce the flow rate of cooling air while suppressing thermal damage.

[0009] To achieve the above object, one embodiment of a flow path forming plate according to the invention comprises: a gas path surface that defines a portion of a combustion gas flow path through which combustion gas flows; a side surface that extends from the edge of the gas path surface toward the opposite gas path side, away from the combustion gas flow path; a cavity defining surface that is recessed from the opposite gas path side toward the gas path side opposite the opposite gas path side and defines a cavity through which cooling air can flow; and a cooling air passage through which the cooling air that has flowed into the cavity can flow. The side surface has a rear end surface that faces downstream of the flow of fuel gas flowing through the combustion gas flow path. The cooling air passage has a plurality of rear end ejection passages that are aligned laterally along the gas path surface and the rear end surface and open at the rear end surface. The plurality of rear end ejection passages include a plurality of small rear end ejection passages and a plurality of large rear end ejection passages. Among the plurality of rear-end ejection large passages, some of the rear-end ejection large passages are arranged closest to at least one of a first side and a second side in the lateral direction, adjacent to each other in the lateral direction. The passage cross-sectional area of ​​each of the plurality of rear-end ejection large passages is larger than the passage cross-sectional area of ​​any of the plurality of rear-end ejection small passages.

[0010] In this aspect, the multiple rear end jet passages opening at the rear end surface include multiple rear end jet small passages and multiple rear end jet large passages. Therefore, in this aspect, the possibility that all of the rear end jet passages will be clogged with foreign matter is reduced, reducing a decrease in cooling effect due to clogging with foreign matter and suppressing thermal damage to the passage forming plate. Furthermore, foreign matter is likely to flow into the rear end jet passages on the first and second lateral sides. In this aspect, the multiple rear end jet passages closest to at least one of the first and second sides are all rear end jet large passages. Therefore, in this aspect, the possibility that the multiple rear end jet passages on at least one of the first and second sides will be clogged with foreign matter is reduced. Furthermore, in this aspect, since not all of the multiple rear end jet passages opening at the rear end surface are rear end jet large passages, a decrease in gas turbine efficiency due to an increase in the flow rate of cooling air supplied to the passage forming plate is suppressed.

[0011] To achieve the above object, one aspect of the invention provides a stator vane comprising: a blade body having an airfoil-shaped cross section and extending in a blade height direction having a component perpendicular to the cross section; and an inner shroud and an outer shroud connected to the blade body and extending in a direction perpendicular to the blade height direction. The inner shroud is connected to one end of the blade body on one side of both sides in the blade height direction. The outer shroud is connected to the other end of the blade body. At least one of the inner shroud and the outer shroud is the flow passage forming plate according to the above aspect.

[0012] According to one aspect of the present invention, there is provided a gas turbine comprising: a flow passage forming plate according to the above aspect; a turbine rotor rotatable about an axis; and a turbine casing covering the flow passage forming plate and the turbine rotor. The turbine rotor has a plurality of rows of moving blades arranged in an axial direction along the axis, and a rotor shaft to which the plurality of rows of moving blades are attached, the rotor shaft extending in the axial direction around the axis. The combustion gas flow passage is a space within the turbine casing that forms an annular shape around the axis, is located on the outer periphery of the rotor shaft, and extends in the axial direction.

[0013] According to one aspect of the present disclosure, the flow rate of cooling air can be reduced while suppressing thermal damage.

[0014] Fig. 1 is a schematic cross-sectional view of a gas turbine in an embodiment according to the present disclosure. Fig. 2 is a cross-sectional view of a main portion of a gas turbine in an embodiment according to the present disclosure. Fig. 3 is a perspective view of a stator vane in a first embodiment according to the present disclosure. Fig. 4 is a cross-sectional view taken along line V-V in Fig. 3. Fig. 5 is a cross-sectional view taken along line VI-VI in Fig. 4. Fig. 5 is a cross-sectional view of an outer shroud of a stator vane in a second embodiment according to the present disclosure. Fig. 6 is a cross-sectional view of an outer shroud of a stator vane in a third embodiment according to the present disclosure. Fig. 6 is a perspective view of a ring segment in an embodiment according to the present disclosure.

[0015] Hereinafter, embodiments of a turbine component according to the present disclosure and a turbine including the turbine component will be described in detail with reference to the drawings.

[0016] Gas Turbine Embodiment An embodiment of a gas turbine will be described with reference to FIGS. 1 and 2. FIG.

[0017] As shown in FIG. 1 , the gas turbine 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 includes a compressor rotor 11 that rotates about an axis Ar, a compressor casing 18 that covers the compressor rotor 11, and a plurality of stator vane rows 15. The turbine 30 includes a turbine rotor 31 that rotates about the axis Ar, a turbine casing 38 that covers the turbine rotor 31, and a plurality of stator vane rows 35. In the following, 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. 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 relative 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 1. To this gas turbine rotor 1, for example, a rotor of a generator GEN is connected. The gas turbine further includes an intermediate casing 6. This intermediate casing 6 is arranged between the compressor casing 18 and the turbine casing 38 in the axial direction Da. The compressor casing 18, the intermediate casing 6, and the turbine casing 38 are connected to each other to form the gas turbine casing 8.

[0021] As shown in Figures 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 the plurality of stator blade rows 15 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 13. Each stator blade row 15 is provided inside a compressor casing 18. Each stator blade row 15 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 composed of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 35 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 33. Each stator blade row 35 is provided inside a turbine casing 38. Each stator blade row 35 is composed of a plurality of stator blades 36 aligned in the circumferential direction Dc.

[0023] The stator vane 36 has a blade body 36b extending in the radial direction Dr, an outer shroud 36o connected to an end of the blade body 36b on the radially outer side Dro, and an inner shroud 36i connected to an end of the blade body 36b on the radially inner side Dri. The blade body 36b has an airfoil-shaped cross section perpendicular to the direction in which the blade body 36b extends. Both the outer shroud 36o and the inner shroud 36i extend in a direction perpendicular to the direction in which the blade body 36b extends.

[0024] The annular space between the outer circumferential side of the rotor shaft 32 and the inner circumferential side of the turbine casing 38, in which the rotor blade row 33 and the stator blade row 35 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. This combustion gas flow path 39 forms an annular shape centered on the axis Ar and extends in the axial direction Da.

[0025] The outer shroud 36o of the stator vane 36 defines a portion of the edge of the radially outer side Dro of the combustion gas flow path 39. The inner shroud 36i of the stator vane 36 defines a portion of the edge of the radially inner side Dri of the combustion gas flow path 39. Thus, both the outer shroud 36o and the inner shroud 36i are flow path forming plates that define a portion of the combustion gas flow path 39.

[0026] In addition to the plurality of stator vanes 36, a plurality of ring segments 37 are provided inside the turbine casing 38. The ring segments 37 are located at positions where the rotor blade row 33 exists in the axial direction Da, on the radially outer side Dro of the rotor blade row 33. Therefore, the ring segments 37 are located between the plurality of stator blade rows 35 lined up in the axial direction Da. The ring segments 37 define part of the edge of the radially outer side Dro of the combustion gas flow path 39. Therefore, the ring segments 37 are also flow path forming plates that define part of the combustion gas flow path 39.

[0027] The combustor 20 is attached to the intermediate casing 6. As shown in Fig. 2 , 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.

[0028] As described above, the outer shroud 36o and the inner shroud 36i of the stator blade 36, and further the ring segment 37 are all flow passage forming plates. Therefore, hereinafter, an embodiment of the stator blade and an embodiment of the ring segment will be described.

[0029] First Embodiment of Stator Vane A first embodiment of the stator vane will be described with reference to FIGS.

[0030] As shown in FIGS. 3 and 4, the stator blade 50 in this embodiment includes a blade body 51, an outer shroud 60o, and an inner shroud 60i.

[0031] The blade body 51 has an airfoil-shaped cross section and extends in a blade height direction Dh having a directional component perpendicular to the cross section. The inner shroud 60i is provided at one end of the blade body 51 in the blade height direction Dh. The inner shroud 60i extends in a direction perpendicular to the blade height direction Dh. The outer shroud 60o is provided at the other end of the blade body 51 in the blade height direction Dh. The outer shroud 60o extends in a direction perpendicular to the blade height direction Dh.

[0032] When the stator vane 50 is attached to the turbine casing 38 (see FIG. 2 ), the blade height direction Dh becomes the radial direction Dr. One side of the blade height direction Dh becomes the radially inner side Dri, and the other side of the blade height direction Dh becomes the radially outer side Dro. Therefore, the inner shroud 60i is provided at the end of the radially inner side Dri of the blade body 51, and the outer shroud 60o is provided at the end of the radially outer side Dro of the blade body 51.

[0033] The blade body 51 has a leading edge 52, a trailing edge 53, a suction surface (suction side) 54 which is a convex surface, and a pressure surface (ventral side) 55 which is a concave surface. The leading edge 52 and the trailing edge 53 are located at the connection between the suction surface 54 and the pressure surface 55. The leading edge 52, the trailing edge 53, the suction surface 54, and the pressure surface 55 all extend in the blade height direction Dh. When the stator vane 50 is attached to the turbine casing 38 (see FIG. 2), the leading edge 52 and the trailing edge 53 are aligned in the axial direction Da. The leading edge 52 is located axially upstream Dau of the trailing edge 53. When the stator vane 50 is attached to the turbine casing 38 (see FIG. 2), the suction surface 54 and the pressure surface 55 are aligned in the circumferential direction Dc.

[0034] The blade body 51 is disposed in the combustion gas flow path 39 through which the combustion gas G passes. As described above, the inner shroud 60i defines a portion of the edge of the radially inner side Dri of the annular combustion gas flow path 39. Also, as described above, the outer shroud 60o defines a portion of the edge of the radially outer side Dro of the annular combustion gas flow path 39.

[0035] As shown in FIGS. 3 and 5, the outer shroud 60o has a shroud body 61, a front hook 68f, and a rear hook 68r.

[0036] The shroud body 61 has a gas path surface 61 g , an anti-gas path surface 61 ag , a side surface 61 s , and a cavity-defining surface 62 .

[0037] The gas path surface 61g defines a portion of the edge of the radially outer side Dro of the annular combustion gas flow path 39. The counter-gas path surface 61ag faces the counter-gas path side Dag, which is away from the combustion gas flow path 39. The gas path surface 61g faces the gas path side Dg, which is opposite the counter-gas path surface 61ag. Therefore, the gas path surface 61g and the counter-gas path surface 61ag are back-to-back. Note that, when the stator vane 50 is attached to the turbine casing 38 (see FIG. 2), the gas path side Dg of the outer shroud 60o becomes the radially inner side Dri, and the counter-gas path side Dag becomes the radially outer side Dro. The gas path surface 61g and the counter-gas path surface 61ag form a parallelogram when viewed from the gas path side Dg or the counter-gas path side Dag.

[0038] The side surface 61s connects the edge of the gas path surface 61g and the edge of the opposite gas path surface 61ag. Therefore, the side surface 61s extends from the edge of the gas path surface 61g toward the opposite gas path side Dag. The side surface 61s has a front end surface 61sf, a rear end surface 61sr, a first side end surface 61s1, and a second side end surface 61s2. The rear end surface 61sr faces the downstream side Dad of the flow of combustion gas G flowing through the combustion gas flow path 39. In other words, the rear end surface 61sr faces the axial downstream side Dad. On the other hand, the front end surface 61sf faces the upstream side Dau of the flow of combustion gas G. In other words, the front end surface 61sf faces the axial upstream side Dau. The first side end surface 61s1 faces a first side Dc1 in the lateral direction Dc along the gas path surface 61g and the rear end surface 61sr. This first side end surface 61s1 connects an edge of the first side Dc1 of the leading end surface 61sf to an edge of the first side Dc1 of the rear end surface 61sr. The second side end surface 61s2 faces a second side Dc2. This second side end surface 61s2 connects an edge of the second side Dc2 of the leading end surface 61sf to an edge of the second side Dc2 of the rear end surface 61sr. Note that when the stator vane 50 is attached to the turbine casing 38 (see FIG. 2 ), the lateral direction Dc becomes the circumferential direction Dc.

[0039] The cavity defining surface 62 defines a cavity C into which the cooling air Ac1 can flow. The cavity C is a space recessed from the opposite gas path surface 61ag toward the gas path side Dg. The cavity defining surface 62 includes a bottom surface 62b, a front defining surface 62f, a rear defining surface 62r, a first side defining surface 62s1, and a second side defining surface 62s2. The bottom surface 62b faces the opposite gas path side Dag and is located closer to the gas path side Dg than the opposite gas path surface 61ag. When viewed from the opposite gas path side Dag, the bottom surface 62b has a parallelogram shape, similar to the gas path surface 61g. The front defining surface 62f faces the downstream side Dad and extends from the edge of the bottom surface 62b on the upstream side Dau toward the opposite gas path side Dag. The rear defining surface 62r faces the upstream side Dau and extends from the edge of the downstream side Dad of the bottom surface 62b to the opposite gas path side Dag. The first side defining surface 62s1 faces the second side Dc2 and extends from the edge of the first side Dc1 of the bottom surface 62b to the opposite gas path side Dag. This first side defining surface 62s1 connects the edge of the first side Dc1 of the front defining surface 62f to the edge of the first side Dc1 of the rear defining surface 62r. ​​The second side defining surface 62s2 faces the first side Dc1 and extends from the edge of the second side Dc2 of the bottom surface 62b to the opposite gas path side Dag. This second side defining surface 62s2 connects the edge of the second side Dc2 of the front defining surface 62f to the edge of the second side Dc2 of the rear defining surface 62r.

[0040] The front hook 68f is formed to protrude from the opposite gas path surface 61ag to the opposite gas path side Dag along the front end surface 61sf. The rear hook 68r is formed to protrude from the opposite gas path surface 61ag to the opposite gas path side Dag along the rear end surface 61sr. Both the front hook 68f and the rear hook 68r serve to attach the stator vane 50 to the turbine casing 38.

[0041] As shown in FIGS. 4 and 6 , the inner shroud 60 i includes a shroud body 61 and a retainer 69 .

[0042] The shroud body 61 has a gas path surface 61g, an anti-gas path surface 61ag, a side surface 61s, and a cavity-defining surface 62, similar to the shroud body 61 of the outer shroud 60o.

[0043] The gas path surface 61g defines a part of the edge of the radially inner side Dri of the annular combustion gas flow path 39. The counter-gas path surface 61ag faces the counter-gas path side Dag away from the combustion gas flow path 39. The gas path surface 61g faces the gas path side Dg opposite to the counter-gas path surface 61ag. Note that when the stator vane 50 is attached to the turbine casing 38 (see FIG. 2 ), the gas path side Dg of the inner shroud 60i becomes the radially outer side Dro, and the counter-gas path side Dag becomes the radially inner side Dri. The gas path surface 61g and the counter-gas path surface 61ag form a parallelogram when viewed from the gas path side Dg or the counter-gas path side Dag.

[0044] The side surface 61s connects the edge of the gas path surface 61g and the edge of the opposite gas path surface 61ag. Therefore, the side surface 61s extends from the edge of the gas path surface 61g to the opposite gas path side Dag. Like the side surface 61s of the shroud body 61 of the outer shroud 60o, the side surface 61s has a front end surface 61sf, a rear end surface 61sr, a first side end surface 61s1, and a second side end surface 61s2. The rear end surface 61sr faces the downstream side Dad of the flow of fuel gas flowing through the combustion gas flow passage 39. In other words, the rear end surface 61sr faces the axial downstream side Dad. On the other hand, the front end surface 61sf faces the upstream side Dau of the combustion gas flow. In other words, the front end surface 61sf faces the axial upstream side Dau. The first side end face 61s1 faces a first side Dc1 in the lateral direction Dc. This first side end face 61s1 connects an edge of the first side Dc1 of the front end face 61sf to an edge of the first side Dc1 of the rear end face 61sr. The second side end face 61s2 faces a second side Dc2 in the lateral direction Dc. This second side end face 61s2 connects an edge of the second side Dc2 of the front end face 61sf to an edge of the second side Dc2 of the rear end face 61sr.

[0045] The cavity-defining surface 62 is a surface that defines a cavity C into which the cooling air Ac1 can flow. This cavity C is a space recessed from the opposite-gas path surface 61ag toward the gas path side Dg. Like the cavity-defining surface 62 of the outer shroud 60o, the cavity-defining surface 62 has a bottom surface 62b, a front defining surface 62f, a rear defining surface 62r, a first side defining surface 62s1, and a second side defining surface 62s2. The bottom surface 62b faces the opposite-gas path side Dag and is located closer to the gas path side Dg than the opposite-gas path surface 61ag. Like the gas path surface 61g, the bottom surface 62b has a parallelogram shape when viewed from the opposite-gas path side Dag. The front defining surface 62f faces the downstream side Dad and extends from the edge of the bottom surface 62b on the upstream side Dau to the opposite side of the gas path Dag. The rear defining surface 62r faces the upstream side Dau and extends from the edge of the bottom surface 62b on the downstream side Dad to the opposite side of the gas path Dag. The first side defining surface 62s1 faces the second side Dc2 and extends from the edge of the first side Dc1 of the bottom surface 62b to the opposite side of the gas path Dag. This first side defining surface 62s1 connects the edge of the first side Dc1 of the front defining surface 62f and the edge of the first side Dc1 of the rear defining surface 62r. ​​The second side defining surface 62s2 faces the first side Dc1 and extends from the edge of the second side Dc2 of the bottom surface 62b to the opposite side of the gas path Dag. This second side defining surface 62s2 connects the edge of the second side Dc2 of the front defining surface 62f and the edge of the second side Dc2 of the rear defining surface 62r.

[0046] The retainer 69 is located between the front end surface 61sf and the rear end surface 61sr, and is formed from the first side end surface 61s1 to the second side end surface 61s2. The retainer 69 is connected to the end of the radially outer side Dro of the inner cover 7 (see FIG. 2 ) fixed to the gas turbine casing 8, and serves to support the radially inner side Dri portion of the stator blade 50 on the inner cover 7.

[0047] As shown in FIG. 3 , a plurality of blade air passages 56 extending in the radial direction Dr are formed in the blade body 51, the outer shroud 60o, and the inner shroud 60i. Each blade air passage 56 is formed continuously from the outer shroud 60o through the blade body 51 to the inner shroud 60i. The plurality of blade air passages 56 are aligned along the camber line CL of the blade body 51. Some of the adjacent blade air passages 56 communicate with each other at the radially outer portion Dro or the radially inner portion Dri. In addition, any of the plurality of blade air passages 56 opens at the bottom surface 62b of the cavity-defining surface 62 of the outer shroud 60o. Note that any of the plurality of blade air passages 56 may also open at the bottom surface 62b of the cavity-defining surface 62 of the inner shroud 60i.

[0048] The cooling air Ac1 flows into the cavity C of the outer shroud 60o from the radially outer side Dro of this cavity C. Also, the cooling air Ac1 flows into the cavity C of the inner shroud 60i from the radially inner side Dri of this cavity C. Note that part of the cooling air Ac1 that has flowed into the cavity C of the outer shroud 60o may also flow into the cavity C of the inner shroud 60i via any one of the multiple blade air passages 56.

[0049] 5 , the outer shroud 60o has a cooling air passage 63 through which the cooling air Ac1 that has flowed into the cavity C of the outer shroud 60o can flow. The cooling air passage 63 has a first side passage 63a, a second side passage 63b, a rear end passage 64, and a plurality of rear end ejection passages 65.

[0050] The first side passage 63a allows the cooling air Ac1 within the cavity C to flow in. The first side passage 63a has a front side passage portion 63af and a first side passage portion 63a1. The front side passage portion 63af opens at the front defining surface 62f of the cavity defining surface 62. The front side passage portion 63af extends from the opening of the front side passage portion 63af to the first side Dc1 between the front end surface 61sf of the outer shroud 60o and the front defining surface 62f of the cavity defining surface 62. The first side passage portion 63a1 extends in a direction along the first side end surface 61s1 between the first side end surface 61s1 of the outer shroud 60o and the first side defining surface 62s1 of the cavity defining surface 62. An upstream side Dau portion of the first side passage portion 63a1 communicates with the front side passage portion 63af. The first side passage portion 63 a 1 extends between a rear end surface 61 sr of the outer shroud 60 o and a rear defining surface 62 r of the cavity defining surface 62 .

[0051] The second side passage 63b allows the cooling air Ac1 within the cavity C to flow into the second side passage 63b. The second side passage 63b has a front side passage portion 63bf and a second side passage portion 63b2. The front side passage portion 63bf opens at the front defining surface 62f of the cavity defining surface 62. The front side passage portion 63bf extends from the opening of the front side passage portion 63bf to the second side Dc2 between the front end surface 61sf of the outer shroud 60o and the front defining surface 62f of the cavity defining surface 62. The second side passage portion 63b2 extends in a direction along the second side end surface 61s2 between the second side end surface 61s2 of the outer shroud 60o and the second side defining surface 62s2 of the cavity defining surface 62. An upstream side Dau portion of the second side passage portion 63b2 communicates with the front side passage portion 63bf. The second side passage portion 63b2 extends between the rear end surface 61sr of the outer shroud 60o and the rear defining surface 62r of the cavity defining surface 62.

[0052] The rear end passage 64 extends in the lateral direction Dc at a rear end portion between the rear end surface 61sr of the outer shroud 60o and the rear defining surface 62r of the cavity defining surface 62. A first side Dc1 end of the rear end passage 64 communicates with the first side passage 63a. A second side Dc2 end of the rear end passage 64 communicates with the second side passage 63b.

[0053] Each of the multiple rear-end jet passages 65 communicates with the rear-end passage 64 and opens at the rear end surface 61sr of the outer shroud 60o. The multiple rear-end jet passages 65 include multiple rear-end jet small passages 65s and multiple rear-end jet large passages 65l. The cross-sectional area of ​​each of the multiple rear-end jet large passages 65l is larger than the cross-sectional area of ​​any of the multiple rear-end jet small passages 65s. Note that the cross-sectional area here refers to the area of ​​a cross section perpendicular to the direction in which the passage extends. The inner diameter of the rear-end jet small passage 65s is, for example, 1.0 mm, and the inner diameter of the rear-end jet large passage 65l is, for example, 2.0 mm.

[0054] The rear end surface 61sr of the outer shroud 60o has a central region A3 including the center in the lateral direction Dc, a first side region A1 adjacent to the central region A3 and positioned on a first side Dc1 from the central region A3, and a second side region A2 adjacent to the central region A3 and positioned on a second side Dc2 from the central region A3. A plurality of rear end jet passages 65 open in each of the central region A3, the first side region A1, and the second side region A2.

[0055] In the central region A3 of the rear end surface 61sr, the small rear-end jet passages 65s and the large rear-end jet passages 65l open alternately in the lateral direction Dc. Therefore, in the outer shroud 60o of this embodiment, this central region A3 is an alternating region A4.

[0056] Of the multiple rear end jet passages 65 that open in the first side region A1, the one rear end jet passage 65 that is located closest to the first side Dc1, or multiple rear end jet passages 65 that include one rear end jet passage 65 and are adjacent to each other, all form a first side rear end jet passage 65c1. In this embodiment, a total of two rear end jet passages 65, the one rear end jet passage 65 that is located closest to the first side Dc1 and the one rear end jet passage 65 adjacent to that one rear end jet passage 65, form the first side rear end jet passage 65c1. Furthermore, of the multiple rear end jet passages 65 that open in the second side region A2, the one rear end jet passage 65 that is located closest to the second side Dc2, or multiple rear end jet passages 65 that include one rear end jet passage 65 and are adjacent to each other, all form second side rear end jet passages 65c2. In this embodiment, the second-side rear-end jet passage 65c2 is made up of a total of two rear-end jet passages 65: one rear-end jet passage 65 located closest to the second side Dc2 and one rear-end jet passage 65 adjacent to this one rear-end jet passage 65. The first-side rear-end jet passage 65c1 and the second-side rear-end jet passage 65c2 are both large rear-end jet passages 65l.

[0057] Of the multiple rear end jet passages 65 that open in the first side region A1, all of them except for the first side rear end jet passage 65c1 are small rear end jet passages 65s. Also, of the multiple rear end jet passages 65 that open in the second side region A2, all of them except for the second side rear end jet passage 65c2 are small rear end jet passages 65s.

[0058] The pitch P1 between the plurality of rear-end jet small passages 65s opening in the first side region A1 and the pitch P2 between the plurality of rear-end jet small passages 65s opening in the second side region A2 are narrower than the pitch P3 between the plurality of rear-end jet small passages 65s opening in the central region A3 (=alternate region A4) and the plurality of rear-end jet large passages 651 adjacent in the lateral direction Dc. In this embodiment, the pitch P1 between the plurality of rear-end jet small passages 65s opening in the first side region A1 and the pitch P2 between the plurality of rear-end jet small passages 65s opening in the second side region A2 are, for example, 10.0 mm, which is 10 times the inner diameter (e.g., 1.0 mm) of the rear-end jet small passages 65s. The pitch P3 between the multiple passages opening in the central region A3 (=alternating region A4) is, for example, 15.0 mm, which is 15 times the inner diameter (for example, 1.0 mm) of the small rear-end jet passage 65s. The spacing Pc between the two first-side rear-end jet passages 65c1 and the spacing Pc between the two second-side rear-end jet passages 65c2 are, for example, 1.3 mm, which is wider than the pitches P1 and P2.

[0059] A portion of the cooling air Ac1 that flows into the cavity C of the outer shroud 60o flows into the first side passage 63a, and another portion flows into the second side passage 63b. The cooling air Ac1 that flows into the first side passage 63a flows through the first side passage 63a and into the rear end passage 64. The cooling air Ac1 that flows from the first side passage 63a into the rear end passage 64 flows through the rear end passage 64 toward the second side Dc2. During this process, the cooling air Ac1 is ejected from the rear end surface 61sr via the multiple rear end ejection passages 65. The cooling air Ac1 that flows into the second side passage 63b flows through the second side passage 63b and into the rear end passage 64. The cooling air Ac1 that flows from the second side passage 63b into the rear end passage 64 flows through the rear end passage 64 toward the first side Dc1. During this process, the cooling air Ac1 passes through the multiple rear end ejection passages 65 and is ejected from the rear end surface 61sr.

[0060] The cooling air Ac1 flowing through the cooling air passage 63 generally contains small amounts of foreign matter such as metal powder and dust. Therefore, if all rear-end ejection passages 65 were configured as small rear-end ejection passages 65s, each of the rear-end ejection passages 65 would be prone to clogging with foreign matter. If foreign matter were to clog the rear-end ejection passages 65, the cooling effect of the portion of the outer shroud 60o, which serves as a passage forming plate, near the passage clogged with foreign matter would decrease, increasing the likelihood of thermal damage to the outer shroud 60o within a short period of time. Conversely, if all rear-end ejection passages 65 were configured as large rear-end ejection passages 65l, the flow rate of the cooling air Ac1 supplied to the outer shroud 60o, which serves as a passage forming plate, would increase, resulting in a decrease in gas turbine efficiency.

[0061] In this embodiment, the multiple rear-end jet passages 65 opening in the rear end surface 61sr include multiple rear-end jet small passages 65s and multiple rear-end jet large passages 65l. This reduces the possibility that all of the rear-end jet passages 65 will be clogged with foreign matter, thereby preventing a decrease in cooling effectiveness due to clogging with foreign matter and reducing thermal damage to the outer shroud 60o. In particular, in this embodiment, even if foreign matter clogs a rear-end jet small passage 65s in the alternating region A4, the cooling air Ac1 flowing through the rear-end jet large passage 65l adjacent to the rear-end jet small passage 65s can cool the area including the area around the rear-end jet small passage 65s. From this perspective, this embodiment also reduces thermal damage to the outer shroud 60o. Furthermore, in this embodiment, since not all of the multiple rear-end ejection passages 65 opening at the rear end surface 61sr are large rear-end ejection passages 65l, it is possible to suppress a decrease in gas turbine efficiency due to an increase in the flow rate of the cooling air Ac1 supplied to the outer shroud 60o.

[0062] Foreign matter that reaches the portion of the rear end passage 64 on the first side Dc1 from the first side passage 63a is subjected to a larger inertial force toward the downstream side Dad than the cooling air Acl that reaches the portion of the rear end passage 64 on the first side Dc1 from the first side passage 63a. In this embodiment, the rear end ejection passages 65 are also connected to the portion of the rear end passage 64 on the first side Dc1, so there is a high possibility that foreign matter will enter these rear end ejection passages 65. However, in this embodiment, of the multiple rear end ejection passages 65 that open in the first side region A1, the two rear end ejection passages 65 that are located furthest to the first side Dc1 are large rear end ejection passages 65l. Therefore, even if foreign matter enters these large rear end ejection passages 65l, there is a low possibility that the foreign matter will clog the rear end ejection passages 65l. Furthermore, in this embodiment, the rear end jet passages 65 are also connected to the portion of the rear end passage 64 on the second side Dc2, and therefore there is a high possibility that foreign matter will enter these rear end jet passages 65. However, in this embodiment, of the multiple rear end jet passages 65 that open in the second side area A2, the two rear end jet passages 65 that are located furthest on the second side Dc2 are large rear end jet passages 65l, and therefore even if foreign matter enters these large rear end jet passages 65l, there is a low possibility that this foreign matter will clog the large rear end jet passages 65l.

[0063] As described above, the cooling air Acl that flows from the first side passage 63a into the rear end passage 64 flows through this rear end passage 64 toward the second side Dc2. During this process, the cooling air Acl is ejected from the rear end surface 61sr via the multiple rear end ejection passages 65. Therefore, the flow rate of the cooling air Acl that flows from the first side passage 63a into the rear end passage 64 gradually decreases as it flows toward the second side Dc2. Therefore, the flow velocity of the cooling air Acl that flows from the first side passage 63a into the rear end passage 64 gradually decreases as it flows toward the second side Dc2. Also, as described above, the cooling air Acl that flows from the second side passage 63b into the rear end passage 64 flows through this rear end passage 64 toward the first side Dc1. During this process, the cooling air Acl is ejected from the rear end surface 61sr via the multiple rear end ejection passages 65. For this reason, the flow rate of the cooling air Ac1 flowing from the second side passage 63b into the rear end passage 64 gradually decreases toward the first side Dc1. Therefore, the flow velocity of the cooling air Ac1 flowing from the second side passage 63b into the rear end passage 64 gradually decreases toward the first side Dc1. That is, in this embodiment, the flow velocity of the cooling air Ac1 flowing from the rear end passage 64 into the rear end ejection passage 65 opening in the central region A3 in the rear end surface 61sr is slower than the flow velocity of the cooling air Ac1 flowing from the rear end passage 64 into the rear end ejection passage 65 opening in the first side region A1 and the second side region A2 in the rear end surface 61sr. For this reason, foreign matter is likely to clog the rear end ejection passage 65 opening in the central region A3 in the rear end surface 61sr. However, in this embodiment, since a portion of the rear end ejection passage 65 that opens in the central region A3 in the rear end face 61sr is the large rear end ejection passage 65l, there is a low possibility that foreign matter will become clogged in all of the rear end ejection passages 65 that open in the central region A3 in the rear end face 61sr.

[0064] As described above, in this embodiment, of the multiple rear end jet passages 65, the rear end jet passages 65 located in areas where foreign matter is likely to enter or where foreign matter is likely to clog are configured as large rear end jet passages 65l. Therefore, in this embodiment, the rear end jet passages 65 located in areas where foreign matter is likely to enter or where foreign matter is likely to clog are less likely to be clogged with foreign matter. This prevents a decrease in the cooling effect due to clogging of the rear end jet passages 65 located in these areas, thereby preventing thermal damage to the rear end of the outer shroud 60o. Conversely, in this embodiment, the rear end jet passages 65 located in areas other than the areas where foreign matter is likely to enter or where foreign matter is likely to clog are configured as small rear end jet passages 65s. Therefore, in this embodiment, it is possible to suppress a decrease in gas turbine efficiency due to an increase in the flow rate of the cooling air Ac1 supplied to the outer shroud 60o.

[0065] 6, the inner shroud 60i, like the outer shroud 60o, has a cooling air passage 63 through which the cooling air Ac1 that has flowed into the cavity C of the inner shroud 60i can flow. Like the cooling air passage 63 of the outer shroud 60o, this cooling air passage 63 also has a first side passage 63a, a second side passage 63b, a rear end passage 64, and a plurality of rear end ejection passages 65.

[0066] The first side passage 63a allows the cooling air Ac1 within the cavity C in the inner shroud 60i to flow in. Similar to the first side passage 63a of the outer shroud 60o, the first side passage 63a has a front side passage portion 63af and a first side passage portion 63a1.

[0067] The second side passage 63b allows the cooling air Ac1 within the cavity C in the inner shroud 60i to flow in. Similar to the second side passage 63b of the outer shroud 60o, the second side passage 63b has a front side passage portion 63bf and a second side passage portion 63b2.

[0068] The rear end passage 64 extends in the lateral direction Dc at a rear end portion between the rear end surface 61sr of the inner shroud 60i and the rear defining surface 62r of the cavity defining surface 62. A first side Dc1 end of the rear end passage 64 communicates with the first side passage 63a. A second side Dc2 end of the rear end passage 64 communicates with the second side passage 63b.

[0069] Like the multiple rear-end jet passages 65 of the outer shroud 60o, the multiple rear-end jet passages 65 of the inner shroud 60i also have multiple rear-end jet small passages 65s and multiple rear-end jet large passages 65l. The inner diameter of the rear-end jet small passages 65s of the inner shroud 60i is also the same as the inner diameter of the rear-end jet small passages 65s of the outer shroud 60o, e.g., 1.0 mm. The inner diameter of the rear-end jet large passages 65l of the inner shroud 60i is also the same as the inner diameter of the rear-end jet large passages 65l of the outer shroud 60o, e.g., 2.0 mm.

[0070] In the central region A3 in the rear end surface 61sr, the small rear-end jet passages 65s and the large rear-end jet passages 65l open alternately in the lateral direction Dc. Therefore, in the inner shroud 60i of this embodiment, the central region A3 also serves as the alternating region A4.

[0071] Of the multiple rear end jet passages 65 that open in the first side region A1, the one rear end jet passage 65 that is located closest to the first side Dc1, or multiple rear end jet passages 65 that include one rear end jet passage 65 and are adjacent to each other, all form a first side rear end jet passage 65c1. In this embodiment, a total of two rear end jet passages 65, the one rear end jet passage 65 that is located closest to the first side Dc1 and the one rear end jet passage 65 adjacent to that one rear end jet passage 65, form the first side rear end jet passage 65c1. Furthermore, of the multiple rear end jet passages 65 that open in the second side region A2, the one rear end jet passage 65 that is located closest to the second side Dc2, or multiple rear end jet passages 65 that include one rear end jet passage 65 and are adjacent to each other, all form second side rear end jet passages 65c2. In this embodiment, the second-side rear-end jet passage 65c2 is made up of a total of two rear-end jet passages 65: one rear-end jet passage 65 located closest to the second side Dc2 and one rear-end jet passage 65 adjacent to this one rear-end jet passage 65. The first-side rear-end jet passage 65c1 and the second-side rear-end jet passage 65c2 are both large rear-end jet passages 65l.

[0072] Of the multiple rear end jet passages 65 that open in the first side region A1, all of them except for the first side rear end jet passage 65c1 are small rear end jet passages 65s. Also, of the multiple rear end jet passages 65 that open in the second side region A2, all of them except for the second side rear end jet passage 65c2 are small rear end jet passages 65s.

[0073] As described above, the arrangement of the multiple rear end ejection small passages 65s and the multiple rear end ejection large passages 65l in the inner shroud 60i is basically the same as the arrangement of the multiple rear end ejection small passages 65s and the multiple rear end ejection large passages 65l in the outer shroud 60o described above.

[0074] Therefore, in the inner shroud 60i of the present embodiment, as in the outer shroud 60o described above, the possibility that all of the rear-end jet passages 65 will be clogged with foreign matter can be reduced, a decrease in the cooling effect due to clogging with foreign matter can be suppressed, and thermal damage to the inner shroud 60i can be suppressed. Furthermore, in the inner shroud 60i of the present embodiment, as in the outer shroud 60o described above, not all of the multiple rear-end jet passages 65 opening at the rear end surface 61sr are the large rear-end jet passages 65l, and therefore it is possible to suppress a decrease in gas turbine efficiency due to an increase in the flow rate of the cooling air Ac1 supplied to the inner shroud 60i.

[0075] Furthermore, in the inner shroud 60i of this embodiment, as in the outer shroud 60o described above, of the multiple rear end jet passages 65, the rear end jet passages 65 located in areas where foreign matter is likely to enter and the rear end jet passages 65 located in areas where foreign matter is likely to clog are configured as large rear end jet passages 65l. Therefore, in the inner shroud 60i of this embodiment, as in the outer shroud 60o described above, the rear end jet passages 65 located in areas where foreign matter is likely to enter and the rear end jet passages 65 located in areas where foreign matter is likely to clog are less likely to be clogged with foreign matter. Therefore, a decrease in the cooling effect due to clogging by foreign matter in the rear end jet passages 65 located in these areas is suppressed, and thermal damage to the rear end of the inner shroud 60i can be suppressed.

[0076] In the inner shroud 60i of this embodiment, the pitch P1 between the multiple rear-end jet small passages 65s opening in the first-side region A1, the pitch P2 between the multiple rear-end jet small passages 65s opening in the second-side region A2, and the pitch P3 between the multiple rear-end jet small passages 65s and the multiple rear-end jet large passages 65l opening in the central region A3 (=alternating region A4) that are adjacent in the lateral direction Dc are all the same. These pitches P1, P2, and Pc are all, for example, 7.0 mm, which is seven times the inner diameter (e.g., 1.0 mm) of the rear-end jet small passages 65s. Furthermore, the spacing Pc between the two first-side rear-end jet passages 65c1 and the spacing Pc between the two second-side rear-end jet passages 65c2 are, for example, 1.3 mm, which is wider than the pitches P1, P2, and P3. Therefore, in this embodiment, the minimum pitch between the multiple rear end jet passages 65 in the inner shroud 60i is smaller than the minimum pitch between the multiple rear end jet passages 65 in the outer shroud 60o, and the average pitch between the multiple rear end jet passages 65 in the inner shroud 60i is smaller than the average pitch between the multiple rear end jet passages 65 in the outer shroud 60o.

[0077] The magnitude relationship between the pitches P1, P2, and P3 in the inner shroud 60i may be the same as the magnitude relationship between the pitches P1, P2, and P3 in the outer shroud 60o described above. Conversely, the magnitude relationship between the pitches P1, P2, and P3 in the outer shroud 60o may be the same as the magnitude relationship between the pitches P1, P2, and P3 in the inner shroud 60i. Furthermore, the minimum pitch between the multiple rear end jet passages 65 in the inner shroud 60i may be the same as the minimum pitch between the multiple rear end jet passages 65 in the outer shroud 60o, and the average pitch between the multiple rear end jet passages 65 in the inner shroud 60i may be the same as the average pitch between the multiple rear end jet passages 65 in the outer shroud 60o.

[0078] Second Embodiment of Stator Blade A second embodiment of the stator blade will be described.

[0079] Like the stator vane of the first embodiment, the stator vane of this embodiment also has a blade body, an outer shroud, and an inner shroud.

[0080] 7, like the outer shroud 60o in the first embodiment, the outer shroud 60o of the vane in this embodiment also has a cooling air passage 63A through which the cooling air Ac1 that has flowed into the cavity C of the outer shroud 60o can flow. This cooling air passage 63A has a plurality of rear-end jet passages 65A.

[0081] Like the multiple rear end jet passages 65 in the first embodiment, the multiple rear end jet passages 65A in the present embodiment also open at the rear end surface 61sr of the outer shroud 60o. Furthermore, like the multiple rear end jet passages 65 in the first embodiment, the multiple rear end jet passages 65A in the present embodiment also have multiple small rear end jet passages 65As and multiple large rear end jet passages 65Al. However, each of the multiple rear end jet passages 65A in the present embodiment also opens at the rear defining surface 62r of the cavity defining surface 62 or at a corner between the bottom surface 62b of the cavity defining surface 62 and the rear defining surface 62r. ​​Therefore, unlike the multiple rear end jet passages 65 in the first embodiment, a portion of the cooling air Ac1 in the cavity C flows directly into the multiple rear end jet passages 65A in the present embodiment without passing through other cooling air passages.

[0082] The rear end surface 61sr of the outer shroud 60o has a central region A3, a first side region A1, and a second side region A2, similar to the rear end surface 61sr of the outer shroud 60o in the first embodiment. A plurality of rear-end jet passages 65A open in each of the central region A3, the first side region A1, and the second side region A2.

[0083] Two rear end jet passages 65A open in the first side region A1 of the rear end surface 61sr. These two rear end jet passages 65A are both large rear end jet passages 65Al. Two rear end jet passages 65A also open in the second side region A2 of the rear end surface 61sr. These two rear end jet passages 65A are both large rear end jet passages 65Al. Furthermore, multiple rear end jet passages 65A open in the central region A3 of the rear end surface 61sr. In this central region A3, the small rear end jet passages 65As and the large rear end jet passages 65Al open alternately in the lateral direction Dc. Therefore, in the outer shroud 60o of this embodiment, the central region A3 of the rear end surface 61sr is an alternating region A4. The number of rear end jet passages 65A opening in the first side region A1 and the number of rear end jet passages 65A opening in the second side region A2 may be three or more.

[0084] Furthermore, the pitch between the plurality of rear end jet passages 65A that open in the central region A3 in the rear end surface 61sr, the pitch between the plurality of rear end jet passages 65A that open in the first-side region A1 in the rear end surface 61sr, and the pitch between the plurality of rear end jet passages 65A that open in the second-side region A2 in the rear end surface 61sr are the same. However, in the outer shroud 60o of the present embodiment, as in the outer shroud 60o of the first embodiment, the pitch between the plurality of rear end jet passages 65A that open in the first-side region A1 and the pitch between the plurality of rear end jet passages 65A that open in the second-side region A2 may be narrower than the pitch between the plurality of rear end jet passages 65A that open in the central region A3.

[0085] As described above, in the outer shroud 60o of the present embodiment, the multiple rear end jet passages 65A opening at the rear end surface 61sr include the multiple small rear end jet passages 65As and the multiple large rear end jet passages 65Al. Therefore, in the present embodiment as well, the possibility that all of the rear end jet passages 65A will be clogged with foreign matter can be reduced, a reduction in the cooling effect due to clogging by foreign matter can be suppressed, and thermal damage to the outer shroud 60o can be suppressed. Furthermore, in the present embodiment as well, because not all of the multiple rear end jet passages 65A opening at the rear end surface 61sr are the large rear end jet passages 65Al, a reduction in gas turbine efficiency due to an increase in the flow rate of cooling air AcI supplied to the outer shroud 60o can be suppressed.

[0086] Even in the present embodiment, where a portion of the cooling air Ac1 in the cavity C flows directly into the multiple rear end jet passages 65A without passing through other cooling air passages, foreign matter is likely to flow into the multiple rear end jet passages 65A arranged on the first side Dc1 and the second side Dc2 in the lateral direction Dc. This is because foreign matter is likely to collect in the first side Dc1 and the second side Dc2 in the cavity C. In the present embodiment, the multiple rear end jet passages 65A on the first side Dc1 and the multiple rear end jet passages 65A on the second side Dc2 are both large rear end jet passages 65Al. Therefore, in the present embodiment, it is possible to reduce the possibility that the multiple rear end jet passages 65A on the first side Dc1 and the multiple rear end jet passages 65A on the second side Dc2, into which foreign matter is likely to flow, will be clogged with foreign matter.

[0087] While the configuration of the outer shroud 60o of the stator vane in this embodiment has been described above, the inner shroud of the stator vane in this embodiment may also be configured in the same manner as the outer shroud 60o of the stator vane in this embodiment. In this case, as with the stator vane in the first embodiment, the minimum pitch between the multiple aft end jet passages in the inner shroud may be smaller than the minimum pitch between the multiple aft end jet passages 65A in the outer shroud 60o, and the average pitch between the multiple aft end jet passages in the inner shroud may be smaller than the average pitch between the multiple aft end jet passages 65A in the outer shroud 60o.

[0088] Third Embodiment of Stator Vanes A third embodiment of the stator vanes will be described.

[0089] Like the stator vane of the first embodiment, the stator vane of this embodiment also has a blade body, an outer shroud, and an inner shroud.

[0090] 8 , like the outer shroud 60o in the first embodiment, the outer shroud 60o of the vane in this embodiment also has a cooling air passage 63 through which the cooling air Ac1 that has flowed into the cavity C of the outer shroud 60o can flow. Like the cooling air passage 63 in the first embodiment, this cooling air passage 63 has a first side passage 63a, a second side passage 63b, a rear end passage 64, and a plurality of rear end ejection passages 65.

[0091] The first side passage 63a allows the cooling air Ac1 in the cavity C to flow in. Like the first side passage 63a in the first embodiment, this first side passage 63a has a front side passage portion 63af and a first side passage portion 63a1. A passage defining surface that defines the first side passage portion 63a1 of the first side passage 63a has a downstream side defining surface 63a3 that defines the edge of the most downstream side Dad in the first side passage portion 63a1.

[0092] The second side passage 63b allows the cooling air Ac1 in the cavity C to flow in. Similar to the second side passage 63b in the first embodiment, the second side passage 63b has a front side passage portion 63bf and a second side passage portion 63b2. A passage defining surface defining the second side passage portion 63b2 of the second side passage 63b has a downstream side defining surface 63b3 defining the edge of the most downstream side Dad of the second side passage portion 63b2.

[0093] The rear end passage 64 extends in the lateral direction Dc at a rear end portion between the rear end surface 61sr of the outer shroud 60o and the rear defining surface 62r of the cavity defining surface 62. A first side Dc1 end of the rear end passage 64 communicates with the first side passage 63a. A second side Dc2 end of the rear end passage 64 communicates with the second side passage 63b. The passage defining surface that defines the rear end passage 64 has a downstream side defining surface 64d3 that defines the edge of the rear end passage 64 on the most downstream side Dad.

[0094] In this embodiment, a downstream defining surface 63a3 of the first side passage 63a and a downstream defining surface 63b3 of the second side passage 63b are located downstream of a downstream defining surface 64d3 of the rear end passage 64. Therefore, in the first side passage 63a, a portion Dad downstream of the position where the first side passage 63a communicates with the rear end passage 64 forms a pocket portion 63a4. In addition, in the second side passage 63b, a portion Dad downstream of the position where the second side passage 63b communicates with the rear end passage 64 forms a pocket portion 63b4.

[0095] In this embodiment, as in the first embodiment, the multiple rear-end jet passages 65 include multiple small rear-end jet passages 65s and multiple large rear-end jet passages 65l. The cross-sectional area of ​​each of the multiple large rear-end jet passages 65l is larger than the cross-sectional area of ​​any of the multiple small rear-end jet passages 65s.

[0096] In the present embodiment, as in the first embodiment, the rear end surface 61sr of the outer shroud 60o has a central region A3 including the center in the lateral direction Dc, a first side region A1 adjacent to the central region A3 and positioned on the first side Dc1 from the central region A3, and a second side region A2 adjacent to the central region A3 and positioned on the second side Dc2 from the central region A3. A plurality of rear end jet passages 65 open in each of the central region A3, the first side region A1, and the second side region A2.

[0097] The multiple rear-end jet passages 65 opening in the central region A3 in the rear end surface 61sr are all connected to the rear-end passage 64. In this central region A3, the small rear-end jet passages 65s and the large rear-end jet passages 65l open alternately in the lateral direction Dc. Therefore, in the outer shroud 60o of this embodiment, the central region A3 also serves as the alternating region A4.

[0098] Of the multiple rear end jet passages 65 that open in the first side region A1, the one rear end jet passage 65 located closest to the first side Dc1, or multiple rear end jet passages 65 adjacent to one rear end jet passage 65, all form a first side rear end jet passage 65c1. In this embodiment, too, a total of two rear end jet passages 65, consisting of the one rear end jet passage 65 located closest to the first side Dc1 and the one rear end jet passage 65 adjacent to that one rear end jet passage 65, form the first side rear end jet passage 65c1. These first side rear end jet passages 65c1 open at the downstream defining surface 63a3 of the first side passage 63a. Furthermore, among the multiple rear end jet passages 65 that open in the second side region A2, the one rear end jet passage 65 located closest to the second side Dc2, or multiple adjacent rear end jet passages 65 including one rear end jet passage 65, all form the second side rear end jet passage 65c2. In this embodiment, too, a total of two rear end jet passages 65, consisting of the one rear end jet passage 65 located closest to the second side Dc2 and the one rear end jet passage 65 adjacent to that one rear end jet passage 65, form the second side rear end jet passage 65c2. The second side rear end jet passage 65c2 opens at the downstream defining surface 63b3 of the second side passage 63b. The first side rear end jet passage 65c1 and the second side rear end jet passage 65c2 are both large rear end jet passages 65l.

[0099] Of the multiple rear end jet passages 65 that open in the first side region A1, all of the rear end jet passages 65 except for the first side rear end jet passage 65c1 are small rear end jet passages 65s, and all of them are connected to the rear end passage 64. Also, of the multiple rear end jet passages 65 that open in the second side region A2, all of the rear end jet passages 65 except for the second side rear end jet passage 65c2 are small rear end jet passages 65s, and all of them are connected to the rear end passage 64.

[0100] The pitch P1 between the plurality of rear-end jet small passages 65s opening in the first side region A1 and the pitch P2 between the plurality of rear-end jet small passages 65s opening in the second side region A2 are narrower than the pitch P3 between the plurality of rear-end jet small passages 65s opening in the central region A3 (=alternate region A4) and the plurality of rear-end jet large passages 651 adjacent in the lateral direction Dc. In this embodiment, the pitch P1 between the plurality of rear-end jet small passages 65s opening in the first side region A1 and the pitch P2 between the plurality of rear-end jet small passages 65s opening in the second side region A2 are, for example, 10.0 mm, which is 10 times the inner diameter (e.g., 1.0 mm) of the rear-end jet small passages 65s. The pitch P3 between the multiple passages opening in the central region A3 (=alternating region A4) is, for example, 15.0 mm, which is 15 times the inner diameter (for example, 1.0 mm) of the rear end jet small passage 65s.

[0101] As in the first embodiment, a portion of the cooling air Ac1 that flows into the cavity C of the outer shroud 60o flows into the first side passage 63a, and another portion flows into the second side passage 63b.

[0102] The cooling air Ac1 that has flowed into the first-side passage 63a flows through the first-side passage portion 63a1 of the first-side passage 63a toward the downstream side Dad, then flows into the rear-end passage 64, and flows through the rear-end passage 64 toward the second side Dc2. Some of the foreign matter in the cooling air Ac1 flowing through the first-side passage portion 63a1 toward the downstream side Dad does not flow into the rear-end passage 64 together with the cooling air Ac1, but instead travels straight due to inertial force and is collected in the pocket portion 63a4 of the first-side passage portion 63a1. Some of the foreign matter collected in the pocket portion 63a4 of the first-side passage portion 63a1 is ejected from the rear end surface 61sr together with the cooling air Ac1 through a first-side rear-end ejection passage 65c1 that opens at the downstream-side defining surface 63a3 of the first-side passage portion 63a1. This first rear end jet passage 65c1 is the large rear end jet passage 65l, and therefore there is a low possibility that foreign matter will become clogged therein.

[0103] As described above, in the present embodiment, some of the foreign matter in the cooling air Ac1 flowing through the first side passage portion 63a1 is collected in the pocket portion 63a4 of the first side passage portion 63a1, thereby reducing the amount of foreign matter contained in the cooling air Ac1 flowing from the first side passage portion 63a1 into the rear end passage 64. Therefore, in the present embodiment, the possibility of foreign matter clogging the multiple rear end ejection passages 65 communicating with the rear end passage 64 can be reduced.

[0104] The cooling air Ac1 that has flowed into the second-side passage 63b flows through the second-side passage portion 63b2 of the second-side passage 63b toward the downstream side Dad, then flows into the rear-end passage 64, and flows through the rear-end passage 64 toward the second side Dc2. Some of the foreign matter in the cooling air Ac1 flowing through the second-side passage portion 63b2 toward the downstream side Dad does not flow into the rear-end passage 64 together with the cooling air Ac1, but instead travels straight due to inertial force and is collected in the pocket portion 63b4 of the second-side passage portion 63b2. Some of the foreign matter collected in the pocket portion 63b4 of the second-side passage portion 63b2 is ejected from the rear end surface 61sr together with the cooling air Ac1 through the second-side rear-end ejection passage 65c2 that opens at the downstream-side defining surface 63b3 of the second-side passage portion 63b2. This second rear end jet passage 65c2 is the large rear end jet passage 65l, and therefore there is a low possibility that foreign matter will become clogged therein.

[0105] As described above, in the present embodiment, some of the foreign matter in the cooling air Ac1 flowing through the second side passage portion 63b2 is collected in the pocket portion 63b4 of the second side passage portion 63b2, thereby reducing the amount of foreign matter contained in the cooling air Ac1 flowing from the second side passage portion 63b2 into the rear end passage 64. Therefore, in the present embodiment, the possibility of foreign matter clogging the multiple rear end ejection passages 65 communicating with the rear end passage 64 can be reduced.

[0106] Although the configuration of the outer shroud 60o of the stator vane in this embodiment has been described above, the inner shroud of the stator vane in this embodiment may also be configured in the same manner as the outer shroud 60o of the stator vane in this embodiment.

[0107] Embodiment of Split Ring One embodiment of the split ring will be described with reference to FIG.

[0108] The split ring 80 has a split ring main body 81, a front hook 88f, and a rear hook 88r.

[0109] Similar to the shroud body 61 described above, the split ring body 81 has a gas path surface 81g, an anti-gas path surface 81ag, a side surface 81s, a cavity defining surface 82, and a cooling air passage 83.

[0110] The gas path surface 81g faces the gas path side Dg and defines a portion of the edge of the radially outer side Dro of the annular combustion gas flow path 39. This gas path surface 81g has a rectangular shape when viewed from the gas path side Dg. The anti-gas path surface 81ag is back-to-back with the gas path surface 81g and faces the anti-gas path side Dag. When the split ring 80 is attached to the turbine casing 38 (see FIG. 2), the gas path side Dg becomes the radially inner side Dri, and the anti-gas path side Dag becomes the radially outer side Dro.

[0111] The side surface 81s connects the edge of the gas path surface 81g and the edge of the opposite gas path surface 81ag. Therefore, the side surface 81s extends from the edge of the gas path surface 81g toward the opposite gas path side Dag. The side surface 81s has a front end surface 81sf, a rear end surface 81sr, a first side end surface 81s1, and a second side end surface 81s2. The rear end surface 81sr faces the downstream side Dad of the flow of combustion gas G flowing through the combustion gas flow path 39. On the other hand, the front end surface 81sf faces the upstream side Dau of the flow of combustion gas G. The first side end surface 81s1 faces a first side Dc1 in the lateral direction Dc along the gas path surface 81g and the rear end surface 81sr. The first side end surface 81s1 connects an edge of the first side Dc1 of the front end surface 81sf to an edge of the first side Dc1 of the rear end surface 81sr. The second side end surface 81s2 faces the second side Dc2. The second side end surface 81s2 connects an edge of the second side Dc2 of the front end surface 81sf to an edge of the second side Dc2 of the rear end surface 81sr. When the ring segment 80 is attached to the turbine casing 38 (see FIG. 2), the lateral direction Dc becomes the circumferential direction Dc.

[0112] The cavity defining surface 82 defines a cavity C into which the cooling air Ac1 can flow. The cavity C is a space recessed from the opposite gas path surface 81ag toward the gas path side Dg. The cavity defining surface 82 includes a bottom surface 82b, a front defining surface 82f, a rear defining surface 82r, a first side defining surface 82s1, and a second side defining surface 82s2. The bottom surface 82b faces the opposite gas path side Dag and is located closer to the gas path side Dg than the opposite gas path surface 81ag. When viewed from the opposite gas path side Dag, the bottom surface 82b has a rectangular shape, similar to the gas path surface 81g. The front defining surface 82f faces the downstream side Dad and extends from the edge of the bottom surface 82b on the upstream side Dau toward the opposite gas path side Dag. The rear defining surface 82r faces the upstream side Dau and extends from the edge of the downstream side Dad of the bottom surface 82b toward the opposite gas path side Dag. The first side defining surface 82s1 faces the second side Dc2 and extends from the edge of the first side Dc1 of the bottom surface 82b toward the opposite gas path side Dag. This first side defining surface 82s1 connects the edge of the first side Dc1 of the front defining surface 82f to the edge of the first side Dc1 of the rear defining surface 82r. The second side defining surface 82s2 faces the first side Dc1 and extends from the edge of the second side Dc2 of the bottom surface 82b toward the opposite gas path side Dag. This second side defining surface 82s2 connects the edge of the second side Dc2 of the front defining surface 82f to the edge of the second side Dc2 of the rear defining surface 82r.

[0113] The front hook 88f is formed to protrude from the opposite gas path surface 81ag toward the opposite gas path side Dag along the front end face 81sf. The rear hook 88r is formed to protrude from the opposite gas path surface 81ag toward the opposite gas path side Dag along the rear end face 81sr. Both the front hook 88f and the rear hook 88r serve to attach the split ring 80 to the turbine casing.

[0114] The cooling air passage 83 has a plurality of rear-end ejection passages 85. Each of the plurality of rear-end ejection passages 85 has a front passage portion 85f and a main passage portion 85m. The front passage portion 85f opens at the corner between the front defining surface 82f and the bottom surface 82b of the cavity defining surface 82. The front passage portion 85f gradually extends from this opening toward the gas path side Dg as it moves toward the upstream side Dau. The main passage portion 85m extends downstream from the end of the upstream side Dau of the front passage portion 85f between the gas path surface 81g of the split ring 80 and the bottom surface 82b of the cavity defining surface 82 to the rear end surface 81sr of the split ring 80, and opens at this rear end surface 81sr.

[0115] The rear end jet passages 85 include a plurality of small rear end jet passages 85s and a plurality of large rear end jet passages 851. The cross-sectional area of ​​each of the large rear end jet passages 851 is larger than the cross-sectional area of ​​any of the small rear end jet passages 85s.

[0116] Two rear end jet passages 85 open in the first side region A1 of the rear end surface 81sr. These two rear end jet passages 85 are both large rear end jet passages 85l. Two rear end jet passages 85 also open in the second side region A2 of the rear end surface 81sr. These two rear end jet passages 85 are both large rear end jet passages 85l. Furthermore, multiple rear end jet passages 85 open in the central region A3 of the rear end surface 81sr. In this central region A3, the small rear end jet passages 85s and the large rear end jet passages 85l open alternately in the lateral direction Dc. Therefore, in the segment ring body 81 of this embodiment, the central region A3 of the rear end surface 81sr is the alternating region A4. Note that the number of rear end jet passages 85 open in the first side region A1 and the number of rear end jet passages 85 open in the second side region A2 may be three or more.

[0117] As described above, in the ring segment 80 of this embodiment, the multiple rear end jet passages 85 opening at the rear end surface 81sr include multiple rear end jet small passages 85s and multiple rear end jet large passages 85l. Therefore, in this embodiment as well, the possibility that all of the rear end jet passages 85 will be clogged with foreign matter can be reduced, reducing the reduction in cooling effect due to clogging by foreign matter and reducing thermal damage to the ring segment 80. Furthermore, in this embodiment as well, because not all of the multiple rear end jet passages 85 opening at the rear end surface 81sr are rear end jet large passages 85l, it is possible to reduce the reduction in gas turbine efficiency due to an increase in the flow rate of cooling air Ac1 supplied to the ring segment 80.

[0118] Furthermore, in this embodiment, as with the outer shroud 60o in the second embodiment, the possibility of the multiple rear end ejection passages 85 on the first side Dc1 and the multiple rear end ejection passages 85 on the second side Dc2, into which foreign matter is likely to flow, becoming clogged with foreign matter can be reduced.

[0119] The present disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention derived from the content defined in the claims and their equivalents.

[0120] "Additional Notes" The flow path forming plate in the above embodiments can be understood, for example, as follows. (1) A flow path forming plate in a first aspect includes: a gas path surface 61g, 81g that defines a part of a combustion gas flow path 39 through which combustion gas G flows; a side surface 61s, 81s that extends from an edge of the gas path surface 61g, 81g to an opposite gas path side Dag that is away from the combustion gas flow path 39; a cavity defining surface 62, 82 that is recessed from the opposite gas path side Dg to a gas path side Dg opposite to the opposite gas path side Dg and defines a cavity C through which cooling air AcI can flow; and a cooling air passage 63, 63A, 83 through which the cooling air AcI that has flowed into the cavity C can flow. The side surface 61s, 81s has a rear end surface 61sr, 81sr that faces the downstream side Dad of the flow of fuel gas flowing in the combustion gas flow path 39. The cooling air passage 63, 63A, 83 has a plurality of rear-end ejection passages 65, 65A, 85 that are aligned in the lateral direction Dc along the gas path surface 61g, 81g and the rear end face 61sr, 81sr and open at the rear end face 61sr, 81sr. The plurality of rear-end ejection passages 65, 65A, 85 have a plurality of small rear-end ejection passages 65s, 65As, 85s and a plurality of large rear-end ejection passages 65l, 65Al, 85l. Some of the plurality of large rear-end ejection passages 65l, 65Al, 85l are arranged closest to at least one of a first side Dc1 and a second side Dc2 in the lateral direction Dc, and are adjacent to each other in the lateral direction Dc. The cross-sectional area of ​​each of the plurality of rear-end ejection large passages 65l, 65Al, 85l is larger than the cross-sectional area of ​​any of the plurality of rear-end ejection small passages 65s, 65As, 85s.

[0121] In this embodiment, the multiple rear-end jet passages 65, 65A, 85 opening at the rear end faces 61sr, 81sr include multiple small rear-end jet passages 65s, 65As, 85s and multiple large rear-end jet passages 65l, 65Al, 85l. This reduces the likelihood of all of the rear-end jet passages 65, 65A, 85 becoming clogged with foreign matter, thereby preventing a decrease in cooling effectiveness due to clogging and reducing thermal damage to the flow passage forming plate. Furthermore, foreign matter is likely to flow into the rear-end jet passages 65, 65A, 85 on the first side Dc1 and the second side Dc2 in the lateral direction Dc. In this embodiment, the multiple rear-end jet passages 65, 65A, 85 on at least one of the first side Dc1 and the second side Dc2 are all large rear-end jet passages 65l, 65Al, 85l. Therefore, in this aspect, it is possible to reduce the possibility that the multiple rear-end jet passages 65, 65A, 85 on at least one of the first side Dc1 and the second side Dc2 will be clogged with foreign matter. Furthermore, in this aspect, since not all of the multiple rear-end jet passages 65, 65A, 85 opening on the rear end faces 61sr, 81sr are the large rear-end jet passages 65l, 65Al, 85l, it is possible to suppress a decrease in gas turbine efficiency due to an increase in the flow rate of the cooling air Ac1 supplied to the passage forming plate.

[0122] (2) In the second embodiment, the flow path forming plate is such that in the flow path forming plate of the first embodiment, in the rear end surfaces 61sr, 81sr, in an alternating region A4 which is at least a portion of the region in the lateral direction Dc, the small rear end ejection passages 65s, 65As, 85s and the large rear end ejection passages 65l, 65Al, 85l are opened alternately in the lateral direction Dc.

[0123] In this embodiment, even if foreign matter clogs the rear-end ejection small passages 65s, 65As, and 85s in the alternating region A4, the cooling air Ac1 flowing through the rear-end ejection large passages 65l, 65Al, and 85l adjacent to the rear-end ejection small passages 65s, 65As, and 85s can cool the area including the periphery of the rear-end ejection small passages 65s, 65As, and 85s. From this perspective, this embodiment can also suppress thermal damage to the passage-forming plate. Furthermore, in this embodiment, since not all of the multiple rear-end ejection passages 65, 65A, and 85 opening at the rear end faces 61sr and 81sr are the rear-end ejection large passages 65l, 65Al, and 85l, a decrease in gas turbine efficiency due to an increase in the flow rate of the cooling air Ac1 supplied to the passage-forming plate can be suppressed.

[0124] (3) The flow path forming plate in the third aspect is the flow path forming plate in the second aspect, wherein the side surface 61s has a first side end surface 61s1 facing the first side Dc1 and an end of the downstream side Dad connected to the rear end surface 61sr, and a second side end surface 61s2 facing the second side Dc2 and an end of the downstream side Dad connected to the rear end surface 61sr. The cooling air passage 63 includes a first side passage 63a through which the cooling air Ac1 can flow from the cavity C and which has a portion extending in a direction along the gas path surface 61g and the first side end surface 61s1 between the cavity C and the first side end surface 61s1, a second side passage 63b through which the cooling air Ac1 can flow from the cavity C and which has a portion extending in a direction along the gas path surface 61g and the second side end surface 61s2 between the cavity C and the second side end surface 61s2, and a rear end passage 64 which extends in the lateral direction Dc between the cavity C and the rear end surface 61sr, and which communicates with the first side passage 63a on the first side Dc1 and with the second side passage 63b on the second side Dc2. At least some of the multiple rear end jet passages 65 are in communication with the rear end passage 64.

[0125] (4) A flow path forming plate according to a fourth aspect is the flow path forming plate according to the third aspect, wherein the passage defining surface defining the first side passage 63a has a downstream side defining surface 63a3 that defines the edge of the most downstream Dad in the first side passage 63a. The passage defining surface defining the second side passage 63b has a downstream side defining surface 63b3 that defines the edge of the most downstream Dad in the second side passage 63b. The passage defining surface defining the rear end passage 64 has a downstream side defining surface 64d3 that defines the edge of the most downstream Dad in the rear end passage 64. The downstream side defining surface 63a3 of the first side passage 63a and the downstream side defining surface 63b3 of the second side passage 63b are positioned closer to the downstream Dad than the downstream side defining surface 64d3 of the rear end passage 64.

[0126] In this embodiment, a portion of the first side passage 63a downstream of the communication position with the rear end passage 64 forms a pocket portion 63a4. Furthermore, a portion of the second side passage 63b downstream of the communication position with the rear end passage 64 forms a pocket portion 63b4. Therefore, in this embodiment, some of the foreign matter in the cooling air Ac1 flowing through the first side passage 63a is collected in the pocket portion 63a4 of the first side passage 63a. Furthermore, in this embodiment, some of the foreign matter in the cooling air Ac1 flowing through the second side passage 63b is collected in the pocket portion 63b4 of the second side passage 63b. Therefore, in this embodiment, the amount of foreign matter contained in the cooling air Ac1 flowing from the first side passage 63a and the second side passage 63b into the rear end passage 64 can be reduced.

[0127] (5) A flow path forming plate in a fifth aspect is the flow path forming plate in the fourth aspect, wherein some of the plurality of rear-end jet large passages 65l open at the downstream defining surface 63a3 of the first side passages 63a, and some of the plurality of rear-end jet large passages 65l open at the downstream defining surface 63b3 of the second side passages 63b.

[0128] In this embodiment, some of the foreign matter collected in the pockets 63a4 of the first side passages 63a can be ejected to the outside together with the cooling air AcI through the rear-end ejection large passages 65l. Also, some of the foreign matter collected in the pockets 63b4 of the second side passages 63b can be ejected to the outside together with the cooling air AcI through the rear-end ejection large passages 65l. Because the rear-end ejection large passages 65l have a larger passage cross-sectional area than the rear-end ejection small passages 65s, the possibility of these rear-end ejection large passages 65l being clogged with foreign matter can be reduced.

[0129] (6) A sixth aspect of the flow path forming plate is the flow path forming plate of any one of the third to fifth aspects, wherein the rear end surface 61sr has a central region A3 including the center in the lateral direction Dc, a first side region A1 adjacent to the central region A3 and positioned closer to the first side Dc1 than the central region A3, and a second side region A2 adjacent to the central region A3 and positioned closer to the second side Dc2 than the central region A3. Some of the rear end jet passages 65 open in the central region A3 in the rear end surface 61sr. Another part of the rear end jet passages 65 open in the first side region A1 in the rear end surface 61sr. Yet another part of the rear end jet passages 65 open in the second side region A2 in the rear end surface 61sr.

[0130] (7) A seventh aspect of the flow path forming plate is the flow path forming plate of the sixth aspect, wherein the alternating region A4 is a region including the central region A3.

[0131] In this embodiment, the cooling air Ac1 that flows from the first side passage 63a into the rear end passage 64 flows through this rear end passage 64 toward the second side Dc2. During this process, the cooling air Ac1 is ejected from the rear end surface 61sr via the multiple rear end ejection passages 65. Therefore, the flow rate of the cooling air Ac1 that flows from the first side passage 63a into the rear end passage 64 gradually decreases as it flows toward the second side Dc2. Therefore, the flow velocity of the cooling air Ac1 that flows from the first side passage 63a into the rear end passage 64 gradually decreases as it flows toward the second side Dc2. Furthermore, in this embodiment, the cooling air Ac1 that flows from the second side passage 63b into the rear end passage 64 flows through this rear end passage 64 toward the first side Dc1. During this process, the cooling air Ac1 is ejected from the rear end surface 61sr via the multiple rear end ejection passages 65. For this reason, the flow rate of the cooling air Ac1 flowing from the second side passage 63b into the rear end passage 64 gradually decreases toward the first side Dc1. Therefore, the flow velocity of the cooling air Ac1 flowing from the second side passage 63b into the rear end passage 64 gradually decreases toward the first side Dc1. That is, in this embodiment, the flow velocity of the cooling air Ac1 flowing from the rear end passage 64 into the rear end ejection passage 65 opening in the central region A3 in the rear end surface 61sr is slower than the flow velocity of the cooling air Ac1 flowing from the rear end passage 64 into the rear end ejection passage 65 opening in the first side region A1 and the second side region A2 in the rear end surface 61sr. For this reason, foreign matter is likely to clog the rear end ejection passage 65 opening in the central region A3 in the rear end surface 61sr. However, in this embodiment, since a portion of the rear end ejection passage 65 that opens in the central region A3 in the rear end face 61sr is the large rear end ejection passage 65l, the possibility of foreign matter clogging all of the rear end ejection passages 65 that open in the central region A3 in the rear end face 61sr can be reduced.

[0132] (8) In an eighth aspect, in the flow path forming plate of the sixth or seventh aspect, of the plurality of rear end jet passages 65 opening in the first side region A1, one rear end jet passage 65 located closest to the first side Dc1, or a plurality of adjacent rear end jet passages 65 including the one rear end jet passage 65, all form a first side rear end jet passage 65c1. Of the plurality of rear end jet passages 65 opening in the second side region A2, one rear end jet passage 65 located closest to the second side Dc2, or a plurality of adjacent rear end jet passages 65 including the one rear end jet passage 65, all form a second side rear end jet passage 65c2. The first side rear end jet passage 65c1 and the second side rear end jet passage 65c2 are both the large rear end jet passage 65l.

[0133] Foreign matter that reaches the portion of the rear end passage 64 on the first side Dc1 from the first side passage 63a is subjected to a larger inertial force toward the downstream side Dad than the cooling air Acl that reaches the portion of the rear end passage 64 on the first side Dc1 from the first side passage 63a. In this aspect, the rear end ejection passage 65 is also connected to the portion of the rear end passage 64 on the first side Dc1, so there is a high possibility that foreign matter will enter this rear end ejection passage 65. However, in this aspect, among the multiple rear end ejection passages 65 that open in the first side region A1, one or more rear end ejection passages 65 located furthest on the first side Dc1 are large rear end ejection passages 65l. Therefore, even if foreign matter enters one or more rear end ejection passages 65 located furthest on the first side Dc1, the possibility that the foreign matter will clog the one or more rear end ejection passages 65 can be reduced. Furthermore, in this aspect, the rear end jet passage 65 also communicates with the portion of the rear end passage 64 on the second side Dc2, and therefore there is a high possibility that foreign matter will enter this rear end jet passage 65. However, in this aspect, of the multiple rear end jet passages that open in the second side area A2, the one or more rear end jet passages that are located furthest on the second side Dc2 are the large rear end jet passage 651, and therefore even if foreign matter enters the one or more rear end jet passages 65 that are located furthest on the first side Dc1, it is possible to reduce the possibility that the one or more rear end jet passages 65 will become clogged with foreign matter.

[0134] (9) A flow path forming plate according to a ninth aspect is the flow path forming plate according to the eighth aspect, wherein, of the plurality of rear end jet passages 65 opening in the first side region A1, all of the rear end jet passages 65 except for the first side rear end jet passage 65c1 are the small rear end jet passages 65s, and of the plurality of rear end jet passages 65 opening in the second side region A2, all of the rear end jet passages 65 except for the second side rear end jet passage 65c2 are the small rear end jet passages 65s.

[0135] In this embodiment, the flow rate of the cooling air Ac1 supplied to the flow passage forming plate can be reduced.

[0136] (10) In the tenth aspect, the flow path forming plate is such that, in the flow path forming plate of the ninth aspect, the pitch P1 between the plurality of rear end ejection small passages 65s opening in the first side region A1 and the pitch P2 between the plurality of rear end ejection small passages 65s opening in the second side region A2 are narrower than the pitch P3 between the plurality of rear end ejection passages 65 opening in the central region A3.

[0137] (11) In the eleventh aspect, the flow path forming plate is such that, in the flow path forming plate of the ninth aspect, the pitch P1 between the plurality of rear end ejection small passages 65s opening in the first side region A1, the pitch P2 between the plurality of rear end ejection small passages 65s opening in the second side region A2, and the pitch P3 between the plurality of rear end ejection passages 65 opening in the central region A3 are the same.

[0138] (12) A flow path forming plate according to a twelfth aspect is the flow path forming plate according to the first aspect, wherein the plurality of rear end ejection passages (65A, 85) all open at the cavity defining surfaces (62, 82).

[0139] (13) In a thirteenth aspect, the flow path forming plate of the twelfth aspect is such that the rear end surfaces (61sr, 81sr) excluding the areas where the rear end jet passages (65A, 85) located furthest to one side of the rear end surfaces (61sr, 81sr) are open are an alternating area (A4). In the alternating area (A4), the small rear end jet passages (65As, 85s) and the large rear end jet passages (65Al, 85l) are open and alternately arranged in the lateral direction (Dc).

[0140] The stator vanes in the above embodiments can be understood, for example, as follows. (14) A stator vane in a fourteenth aspect comprises a blade body 51 having an airfoil-shaped cross section and extending in a blade height direction Dh having a directional component perpendicular to the cross section, and an inner shroud 60i and an outer shroud 60o connected to the blade body 51 and extending in a direction perpendicular to the blade height direction Dh. The inner shroud 60i is connected to one end of the blade body on one side of both sides in the blade height direction Dh. The outer shroud 60o is connected to the other end of the blade body. At least one of the inner shroud 60i and the outer shroud 60o is the flow passage forming plate in any one of the first to thirteenth aspects.

[0141] In this embodiment, it is possible to suppress the flow rate of the cooling air Ac1 supplied to at least one of the inner shroud 60i and the outer shroud 60o while suppressing thermal damage to this shroud.

[0142] (15) A flow passage forming plate in a fifteenth aspect includes a blade body 51 having an airfoil-shaped cross section and extending in a blade height direction Dh having a directional component perpendicular to the cross section, and an inner shroud 60i and an outer shroud 60o connected to the blade body 51 and extending in a direction perpendicular to the blade height direction Dh. The inner shroud 60i is connected to one end of the blade body on one side of both sides in the blade height direction Dh. The outer shroud 60o is connected to the other end of the blade body. The inner shroud 60i and the outer shroud 60o are both flow passage forming plates in any one of the first to thirteenth aspects. The minimum pitch between the multiple rear end jet passages 65, 65A of the inner shroud 60i is smaller than the minimum pitch between the multiple rear end jet passages 65, 65A of the outer shroud 60o, and the average pitch between the multiple rear end jet passages 65, 65A of the inner shroud 60i is smaller than the average pitch between the multiple rear end jet passages 65, 65A of the outer shroud 60o.

[0143] In this embodiment, the flow rate of the cooling air Ac1 supplied to the inner shroud 60i and the outer shroud 60o can be reduced while suppressing thermal damage to these shrouds. Furthermore, in this embodiment, the cooling effect of the inner shroud 60i can be made greater than the cooling effect of the outer shroud 60o.

[0144] The gas turbines in the above embodiments can be understood as follows, for example. (16) A gas turbine in a sixteenth aspect includes: a flow passage forming plate according to any one of the first to thirteenth aspects; a turbine rotor 31 rotatable about an axis Ar; and a turbine casing 38 covering the flow passage forming plate and the turbine rotor 31. The turbine rotor 31 has a plurality of moving blade rows 33 arranged in an axial direction Da along which the axis Ar extends, and a rotor shaft 32 to which the plurality of moving blade rows 33 are attached, the rotor shaft 32 extending in the axial direction Da around the axis Ar. The combustion gas flow passage 39 is a space within the turbine casing 38 that forms an annular shape around the axis Ar on the outer periphery of the rotor shaft 32 and extends in the axial direction Da.

[0145] According to one aspect of the present disclosure, the flow rate of cooling air can be reduced while suppressing thermal damage.

[0146] 1: Gas turbine rotor 6: Intermediate casing 7: Inner cover 8: Gas turbine casing 10: Compressor 11: Compressor rotor 12: Rotor shaft 13: Row of moving blades 15: Row of stator blades 18: Compressor casing 20: Combustor 21: Burner 22: Transition piece (or combustion duct) 30: Turbine 31: Turbine rotor 32: Rotor shaft 33: Row of moving blades 35: Row of stator blades 36: Stator blade 36b: Blade body 36i: Inner shroud 36o: Outer shroud 37: Ring segment 38: Turbine casing 39: Combustion gas flow path 50: Stator blade 51: Blade body 52: Leading edge 53: Trailing edge 54: Suction surface 55: Pressure surface 56: Blade air passage 60i: Inner shroud 60o: Outer shroud 61: Shroud body 61g: Gas path surface 61ag: Anti-gas path surface 61s: Side surface 61sf: Front end surface 61sr: Rear end surface 61s1: First side end surface 61s2: Second side end surface 62: Cavity defining surface 62b: Bottom surface 62f: Front defining surface 62r: Rear defining surface 62s1: First side defining surface 62s2: Second side defining surface 63, 63A: Cooling air passage 63a: First side passage 63af: Front side passage section 63a1: First side passage section 63a3: Downstream side defining surface 63a4: Pocket section 63b: Second side passage 63bf: Front side passage section 63b2: Second side passage section 63b3: Downstream side defining surface 63b4: Pocket section 64: Rear end passage 64d3: Downstream side defining surface 65, 65A: Rear end jet passage 65s, 65As: Rear end jet small passage 65l,65Al: large rear end jet passage 65c1: first side rear end jet passage 65c2: second side rear end jet passage 68f: front hook 68r: rear hook 69: retainer 80: split ring 81: split ring body 81g: gas path surface 81ag: anti-gas path surface 81s: side surface 81sf: front end surface 81sr: rear end surface 81s1: first side end surface 81s2: second side end surface 82: cavity defining surface 82b: bottom surface 82f: front defining surface 82r: rear defining surface 82s1: first side defining surface 82s2: second side defining surface 83: cooling air passage 85: rear end jet passage 85f: front side passage section 85m: main passage section 85s: small rear end jet passage 85l: large rear end jet passage 88f: Front hook 88r: Rear hook A: Outside air Acom: Compressed air Acl: Cooling air G: Combustion gas F: Fuel C: Cavity A1: First side region A2: Second side region A3: Central region A4: Alternating region Ar: Axis Da: Axial direction Dau: Axial upstream side or upstream side Dad: Axial downstream side or downstream side Dc: Circumferential direction or lateral direction Dc1: First side Dc2: Second side Dg: Gas path side Dga: Counter gas path side Dh: Blade height direction Dr: Radial direction Dri: Radial inner side Dro: Radial outer side

Claims

a gas path surface defining a portion of a combustion gas flow path through which combustion gas flows; a side surface extending from an edge of the gas path surface toward the opposite gas path side away from the combustion gas flow path; a cavity defining surface recessed from the opposite gas path side toward the gas path side opposite the opposite gas path side and defining a cavity through which cooling air can flow; and a cooling air passage through which the cooling air that has flowed into the cavity can flow, wherein the side surface has a rear end surface facing the downstream side of the flow of fuel gas flowing within the combustion gas flow path, and the cooling air passage has a plurality of rear end ejection passages aligned in a lateral direction along the gas path surface and the rear end surface and opening at the rear end surface, the plurality of rear end ejection passages having a plurality of small rear end ejection passages and a plurality of large rear end ejection passages, and among the plurality of large rear end ejection passages, a portion of the plurality of large rear end ejection passages are arranged adjacent to each other in the lateral direction, at least on one of a first side and a second side in the lateral direction, a passage cross-sectional area of ​​each of the plurality of rear-end ejection large passages is larger than a passage cross-sectional area of ​​any of the plurality of rear-end ejection small passages.

2. A flow path forming plate as described in claim 1, wherein in an alternating region which is at least a portion of the rear end surface in the lateral direction, the small rear end ejection passages and the large rear end ejection passages are open and alternately arranged in the lateral direction.

3. A flow passage forming plate as described in claim 2, wherein the side surface has: a first side end face facing the first side, the downstream end being connected to the rear end face; and a second side end face facing the second side, the downstream end being connected to the rear end face, and the cooling air passage has: a first side passage into which cooling air can flow from the cavity and having a portion extending in a direction along the gas path surface and the first side end face between the cavity and the first side end face; a second side passage into which cooling air can flow from the cavity and having a portion extending in a direction along the gas path surface and the second side end face between the cavity and the second side end face; and a rear end passage extending in the lateral direction between the cavity and the rear end face, communicating with the first side passage on the first side and communicating with the second side passage on the second side, and at least a portion of the multiple rear end ejection passages are communicating with the rear end passage.

4. A flow path forming plate as described in claim 3, wherein the passage defining surface defining the first side passage has a downstream defining surface defining the most downstream edge of the first side passage, the passage defining surface defining the second side passage has a downstream defining surface defining the most downstream edge of the second side passage, and the passage defining surface defining the rear end passage has a downstream defining surface defining the most downstream edge of the rear end passage, and the downstream defining surface of the first side passage and the downstream defining surface of the second side passage are located downstream of the downstream defining surface of the rear end passage.

5. A flow path forming plate as described in claim 4, wherein among the plurality of rear-end jet large passages, some of the rear-end jet large passages open at the downstream defining surface of the first side passage, and among the plurality of rear-end jet large passages, some of the other rear-end jet large passages open at the downstream defining surface of the second side passage.

6. A flow path forming plate as described in claim 3, wherein the rear end surface has a central region including the center in the lateral direction, a first side region adjacent to the central region and located on the first side of the central region, and a second side region adjacent to the central region and located on the second side of the central region, a portion of the plurality of rear end jet passages opening in the central region in the rear end surface, a remaining portion of the plurality of rear end jet passages opening in the first side region in the rear end surface, and a further remaining portion of the plurality of rear end jet passages opening in the second side region in the rear end surface.

7. A flow path forming plate according to claim 6, wherein the alternating regions are regions including the central region.

8. A flow path forming plate as described in claim 6, wherein, of the plurality of rear end jet passages opening in the first side region, one rear end jet passage located furthest on the first side, or a plurality of adjacent rear end jet passages including the one rear end jet passage, all form a first side rear end jet passage, and, of the plurality of rear end jet passages opening in the second side region, one rear end jet passage located furthest on the second side, or a plurality of adjacent rear end jet passages including the one rear end jet passage, all form a second side rear end jet passage, and the first side rear end jet passage and the second side rear end jet passage are both the large rear end jet passage.

9. A flow path forming plate as described in claim 8, wherein, of the plurality of rear end jet passages opening in the first side region, all of the rear end jet passages except the first side rear end jet passage are the rear end jet small passages, and, of the plurality of rear end jet passages opening in the second side region, all of the rear end jet passages except the second side rear end jet passage are the rear end jet small passages.

10. A flow path forming plate as described in claim 9, wherein the pitch between the plurality of rear end ejection small passages opening in the first side region and the pitch between the plurality of rear end ejection small passages opening in the second side region are narrower than the pitch between the plurality of rear end ejection passages opening in the central region.

11. A flow path forming plate as described in claim 9, wherein the pitch between the multiple rear end ejection small passages opening in the first side region, the pitch between the multiple rear end ejection small passages opening in the second side region, and the pitch between the multiple rear end ejection passages opening in the central region are the same as each other.

12. A flow passage forming plate as claimed in claim 1, wherein all of the plurality of rear end ejection passages open at the cavity defining surface.

13. A flow path forming plate as described in claim 12, wherein the rear end face, except for the area in which the plurality of rear end ejection passages located furthest to said at least one side are open, is an alternating area, and in said alternating area, the small rear end ejection passages and the large rear end ejection passages are open and alternately arranged in the lateral direction.

14. A stator vane comprising: a blade body having an airfoil-shaped cross section and extending in a blade height direction having a directional component perpendicular to the cross section; and an inner shroud and an outer shroud connected to the blade body and extending in a direction perpendicular to the blade height direction, wherein the inner shroud is connected to an end of the blade body on one side of both sides in the blade height direction, and the outer shroud is connected to an end of the blade body on the other side, and at least one of the inner shroud and the outer shroud is a flow passage forming plate as defined in any one of claims 1 to 13.

15. A vane comprising: a blade body having an airfoil-shaped cross section and extending in a blade height direction having a directional component perpendicular to the cross section; and an inner shroud and an outer shroud connected to the blade body and expanding in a direction perpendicular to the blade height direction, wherein the inner shroud is connected to an end of the blade body on one side of both sides in the blade height direction, and the outer shroud is connected to an end of the blade body on the other side, both of the inner shroud and the outer shroud being flow passage forming plates as defined in any one of claims 1 to 13, and a minimum pitch between the multiple rear end jet passages of the inner shroud is smaller than the minimum pitch between the multiple rear end jet passages of the outer shroud, and an average pitch between the multiple rear end jet passages of the inner shroud is smaller than the average pitch between the multiple rear end jet passages of the outer shroud.

16. A gas turbine comprising: a flow passage forming plate according to any one of claims 1 to 13; a turbine rotor rotatable about an axis; and a turbine casing covering said flow passage forming plate and said turbine rotor, wherein said turbine rotor has a plurality of moving blade rows arranged in the axial direction along which said axis extends, and a rotor shaft to which said plurality of moving blade rows are attached and extending in the axial direction around said axis, and wherein said combustion gas flow passage is a space within said turbine casing that is centered on said axis, forms a ring on the outer periphery of said rotor shaft, and extends in the axial direction.

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