Flow path forming plate, fixed blade, and gas turbine

Abstract

This flow path forming plate is provided with: a gas passage 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 channel is provided with a plurality of rear end spraying channels which are arranged in the side direction and open in the rear end face. And the plurality of rear-end injection channels comprise a plurality of small rear-end injection channels and a plurality of large rear-end injection channels. A part of the plurality of rear-end injection large channels among the plurality of rear-end injection large channels are disposed on the first-most side in the lateral direction and the second-most side in the lateral direction so as to be adjacent to each other in the lateral direction. And the channel sectional area of each channel in the plurality of rear-end injection large channels is larger than that of any channel in the plurality of rear-end injection small channels.

Description

Technical Field

[0001] This invention relates to a flow channel forming plate, fixed blades, and a gas turbine.

[0002] This application claims priority based on Japanese Patent Application No. 2023-197379, filed in Japan on November 21, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] A gas turbine includes a turbine rotor rotating around an axis, multiple fixed blades, multiple segmented rings, and a turbine casing covering these components. The rotor has a rotor shaft and multiple rows of rotating blades mounted on the rotor shaft. The multiple rows of rotating blades are arranged in an axial direction extending from the axis. Each row of rotating blades has multiple rotating blades arranged circumferentially relative to the axis. Furthermore, multiple rows of fixed blades are disposed inside the turbine casing. One of the multiple rows of fixed blades is positioned upstream of each row of rotating blades on its axial direction. Each row of fixed blades has multiple fixed blades arranged circumferentially. Multiple segmented rings are disposed in the portions between the multiple rows of fixed blades in the axial direction, i.e., in the portions where any one row of rotating blades exists in the axial direction.

[0004] The fixed blade has a blade body extending radially relative to its axis and shaped like a blade, an inner shroud disposed radially inward of the blade body, and an outer shroud disposed radially outward of the blade body. The blade body of the fixed blade is disposed within a combustion gas flow channel through which combustion gases pass. The inner shroud defines a portion of the radially inner edge of the combustion gas flow channel. The outer shroud defines a portion of the radially outer edge of the combustion gas flow channel. Furthermore, a dividing ring defines a portion of the radially outer edge of the combustion gas flow channel. Therefore, the inner shroud, the outer shroud, and the dividing ring of the fixed blade constitute a flow channel forming plate having a gas passage surface defining a portion of the combustion gas flow channel and a side surface connected to the edge of the gas passage surface.

[0005] The flow channel forming plate described above is exposed to high-temperature combustion gases. Therefore, the flow channel forming plate is typically cooled using air or the like.

[0006] For example, the flow channel forming plate of the gas turbine described in Patent Document 1 below has multiple cooling air passages that allow cooling air to circulate. A portion of the multiple cooling air passages are injection passages that open on the side of the flow channel forming plate.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2008-138666 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] The cooling air flowing through the cooling air passages typically contains small amounts of foreign matter such as metal powder or dust. Therefore, if the inner diameter of the multiple injection passages is reduced, any of the multiple injection passages may become blocked by foreign matter. In this case, the cooling effect near the blocked passage in the flow channel forming plate will decrease, which may lead to thermal damage to the flow channel forming plate in the short term. Conversely, if the inner diameter of the multiple injection passages is increased, the flow rate of cooling air supplied to the flow channel forming plate will increase, and the efficiency of the gas turbine will decrease.

[0012] Therefore, the object of the present invention is to provide a flow channel forming plate, fixed blades, and gas turbine that can suppress thermal damage and suppress the flow of cooling air.

[0013] Methods for solving problems

[0014] A flow channel forming plate according to one aspect of the invention for achieving the aforementioned objective comprises:

[0015] A gas passage surface defines a portion of a combustion gas flow channel for combustion gas flow; a side surface extends from the edge of the gas passage surface toward a reverse gas passage side away from the combustion gas flow channel; a cavity defining surface is recessed from the reverse gas passage side toward a gas passage side opposite to the reverse gas passage side, defining a cavity through which cooling air can flow; and a cooling air passage allows cooling air flowing into the cavity to circulate. The side surface has a rear end face facing downstream of the flow of fuel gas flowing within the combustion gas flow channel. The cooling air passage has a plurality of rear end injection channels arranged laterally along the gas passage surface and the rear end face and opening at the rear end face. The plurality of rear end injection channels have a plurality of small rear end injection channels and a plurality of large rear end injection channels. A portion of the plurality of large rear end injection channels are arranged adjacent to each other in the lateral direction at the position closest to said side on at least one of the first and second sides in the lateral direction. The cross-sectional area of ​​each of the plurality of large rear end injection channels is larger than the cross-sectional area of ​​any of the plurality of small rear end injection channels.

[0016] In this method, the multiple rear-end injection channels opening at the rear end face have multiple small rear-end injection channels and multiple large rear-end injection channels. Therefore, in this method, the possibility of all rear-end injection channels being blocked by foreign objects can be reduced, the reduction in cooling effect caused by foreign object blockage can be suppressed, and thermal damage to the flow channel forming plate can be suppressed. Furthermore, foreign objects can easily flow into the rear-end injection channels on the first and second sides. In this method, the multiple rear-end injection channels closest to one of the first and second sides are all large rear-end injection channels. Therefore, in this method, the possibility of multiple rear-end injection channels on at least one of the first and second sides being blocked by foreign objects can be reduced. Moreover, in this method, since not all of the multiple rear-end injection channels opening at the rear end face are large rear-end injection channels, the reduction in gas turbine efficiency caused by the increase in the flow rate of cooling air supplied to the flow channel forming plate can be suppressed.

[0017] The fixed blade in one aspect of the invention for achieving the aforementioned objective comprises:

[0018] The blade has a blade-shaped cross-section and extends along a blade height direction having a component perpendicular to the cross-section; an inner shield and an outer shield are connected to the blade and extend along a direction perpendicular to the blade height direction. The inner shield is connected to one end of the blade on one side and the other side of the blade in the blade height direction. The outer shield is connected to the other end of the blade. At least one of the inner shield and the outer shield is a flow channel forming plate in the first embodiment.

[0019] A gas turbine of one aspect of the invention for achieving the aforementioned objective comprises:

[0020] The embodiment includes a flow channel forming plate; a turbine rotor capable of rotating about an axis; and a turbine housing covering the flow channel forming plate and the turbine rotor. The turbine rotor has: a plurality of rotating blade rows arranged along an axial direction extending from the axis; and a rotor shaft on which the plurality of rotating blade rows are mounted and extends along the axial direction from the axis. The combustion gas flow channel is a space within the turbine housing that is annular on the outer periphery of the rotor shaft and extends along the axial direction from the axis.

[0021] Invention Effects

[0022] According to one aspect of the present invention, thermal damage can be suppressed while the flow rate of cooling air is also suppressed. Attached Figure Description

[0023] Figure 1 This is a schematic cross-sectional view of a gas turbine according to one embodiment of the present invention.

[0024] Figure 2 This is a cross-sectional view of the main part of a gas turbine in one embodiment of the present invention.

[0025] Figure 3 This is a perspective view of the fixed blade in the first embodiment of the present invention.

[0026] Figure 4 This is a perspective view of the inner protective cover of the fixed blade in the first embodiment of the present invention.

[0027] Figure 5 It is along Figure 3 A sectional view cut by the VV line.

[0028] Figure 6 It is along Figure 4 A sectional view cut along line VI-VI.

[0029] Figure 7 This is a cross-sectional view of the outer protective cover of the fixed blade in the second embodiment of the present invention.

[0030] Figure 8 This is a cross-sectional view of the outer protective cover of the fixed blade in the third embodiment of the present invention.

[0031] Figure 9 This is a perspective view of the dividing ring in one embodiment of the present invention. Detailed Implementation

[0032] Hereinafter, embodiments of the turbine assembly and the turbine having the turbine assembly according to the present invention will be described in detail with reference to the accompanying drawings.

[0033] "Implementation Methods of Gas Turbines"

[0034] refer to Figure 1 and Figure 2 The implementation method of the gas turbine is described.

[0035] like Figure 1 As shown, the gas turbine in this embodiment includes: a compressor 10 that compresses external 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.

[0036] The compressor 10 includes: a compressor rotor 11 that rotates about an axis Ar; a compressor housing 18 covering the compressor rotor 11; and a plurality of fixed blade rows 15. The turbine 30 includes: a turbine rotor 31 that rotates about an axis Ar; a turbine housing 38 covering the turbine rotor 31; and a plurality of fixed blade rows 35. Furthermore, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction centered on 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. Furthermore, one side of the axial direction Da is designated as the upstream side Dau, and the opposite side is designated as the downstream side Dad. Furthermore, in the radial direction Dr, the side closest to the axis Ar is designated as the radially inner side Dri, and the opposite side is designated as the radially outer side Dro.

[0037] The compressor 10 is positioned on the upstream side of the shaft relative to the turbine 30.

[0038] 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. For example, a generator rotor GEN is connected to this gas turbine rotor 1. The gas turbine also includes an intermediate housing 6. This intermediate housing 6 is disposed between the compressor housing 18 and the turbine housing 38 in the axial direction Da. The compressor housing 18, the intermediate housing 6, and the turbine housing 38 are connected to each other to form the gas turbine housing 8.

[0039] like Figure 1 and Figure 2 As shown, the compressor rotor 11 has a rotor shaft 12 extending along the axial direction Da with axis Ar as its center, and multiple rows of rotating blades 13 mounted on the rotor shaft 12. The multiple rows of rotating blades 13 are arranged along the axial direction Da. Each row of rotating blades 13 consists of multiple rotating blades arranged circumferentially Dc. One of multiple fixed blade rows 15 is disposed downstream of each of the multiple rows of rotating blades 13 on the axial direction Dad. Each fixed blade row 15 is located inside the compressor housing 18. Each fixed blade row 15 consists of multiple fixed blades arranged circumferentially Dc.

[0040] The turbine rotor 31 includes: a rotor shaft 32 extending along the axial direction Da with axis Ar as its center; and a plurality of rotating blade rows 33 mounted on the rotor shaft 32. The plurality of rotating blade rows 33 are arranged along the axial direction Da. Each rotating blade row 33 consists of a plurality of rotating blades arranged circumferentially Dc. One of a plurality of fixed blade rows 35 is disposed on the upstream side Dau of each of the plurality of rotating blade rows 33. Each fixed blade row 35 is located inside the turbine housing 38. Each fixed blade row 35 consists of a plurality of fixed blades 36 arranged circumferentially Dc.

[0041] The fixed blade 36 has a blade body 36b extending radially Dr, an outer shield 36o connected to the radially outer end Dro of the blade body 36b, and an inner shield 36i connected to the radially inner end Dri of the blade body 36b. The cross-section of the blade body 36b perpendicular to the direction of its extension is blade-shaped. Both the outer shield 36o and the inner shield 36i extend in a direction perpendicular to the direction of the blade body 36b.

[0042] An annular space between the outer periphery of the rotor shaft 32 and the inner periphery of the turbine housing 38, and arranged along the axial direction Da, forms a combustion gas flow path 39 for the combustion gas G from the combustor 20. This combustion gas flow path 39 is annular about the axis Ar and extends along the axial direction Da.

[0043] The outer shroud 36o of the fixed blade 36 defines a portion of the radially outer edge (Dro) of the combustion gas flow channel 39. The inner shroud 36i of the fixed blade 36 defines a portion of the radially inner edge (Dri) of the combustion gas flow channel 39. Therefore, both the outer shroud 36o and the inner shroud 36i are flow channel forming plates that define a portion of the combustion gas flow channel 39.

[0044] In addition to the multiple fixed blades 36, a plurality of dividing rings 37 are provided on the inner side of the turbine housing 38. The dividing rings 37 are located at positions where rotating blade rows 33 exist in the axial direction Da and are located radially outward of the rotating blade rows 33 (Dro). Therefore, the dividing rings 37 are located between the multiple fixed blade rows 35 arranged along the axial direction Da. The dividing rings 37 define a portion of the radially outward edge (Dro) of the combustion gas flow channel 39. Therefore, the dividing rings 37 are also flow channel forming plates defining a portion of the combustion gas flow channel 39.

[0045] The burner 20 is mounted on the intermediate housing 6. The burner 20 is as follows: Figure 2 As shown, it has: a tail tube (or combustion tube) 22, in which fuel F is burned; and a plurality of combustion furnaces 21, into which fuel is injected.

[0046] As described above, the outer shroud 36o and inner shroud 36i of the fixed blade 36, as well as the dividing ring 37, are all flow channel forming plates. Therefore, the embodiments of the fixed blade and the dividing ring will be described below.

[0047] "First Embodiment of Fixed Blades"

[0048] refer to Figures 3-6 The first embodiment of the fixed blade will be described.

[0049] like Figure 3 and Figure 4 As shown, the fixed blade 50 in this embodiment has a blade body 51, an outer protective cover 60o, and an inner protective cover 60i.

[0050] The blade 51 has a blade-shaped cross-section and extends along a blade height direction Dh that has a directional component perpendicular to the cross-section. An inner shield 60i is disposed at one end of the blade 51 along the blade height direction Dh. This inner shield 60i extends in a direction perpendicular to the blade height direction Dh. An outer shield 60o is disposed at the other end of the blade 51 along the blade height direction Dh. This outer shield 60o extends in a direction perpendicular to the blade height direction Dh.

[0051] With the fixed blade 50 installed on the turbine housing 38 (see reference) Figure 2 Under these conditions, the blade height direction Dh becomes radial Dr. Furthermore, one side of the blade height direction Dh becomes radially inner Dri, and the other side of the blade height direction Dh becomes radially outer Dro. Therefore, the inner shroud 60i is provided at the end of the radially inner Dri of the blade body 51, and the outer shroud 60o is provided at the end of the radially outer Dro of the blade body 51.

[0052] The blade 51 has a leading edge 52, a trailing edge 53, a negative pressure surface (dorsal side) 54 as a convex surface, and a positive pressure surface (ventral side) 55 as a concave surface. The leading edge 52 and trailing edge 53 are present at the junction of the negative pressure surface 54 and the positive pressure surface 55. The leading edge 52, trailing edge 53, negative pressure surface 54, and positive pressure surface 55 all extend in the blade height direction Dh. The blade 50 is mounted on the turbine housing 38 (see reference). Figure 2 With the leading edge 52 and trailing edge 53 aligned along the axial direction Da, the leading edge 52 is located upstream of the axial direction Dau, which is higher than the trailing edge 53. This is in the state where the fixed blade 50 is mounted on the turbine housing 38 (see reference). Figure 2 The negative pressure surface 54 and the positive pressure surface 55 are arranged circumferentially along the Dc direction.

[0053] The blade 51 is disposed within the combustion gas flow channel 39 through which the combustion gas G passes. As described above, the inner shroud 60i defines a portion of the radially inner edge Dri of the annular combustion gas flow channel 39. And, as described above, the outer shroud 60o defines a portion of the radially outer edge Dro of the annular combustion gas flow channel 39.

[0054] like Figure 3 and Figure 5 As shown, the outer protective cover 60o has a protective cover body 61, a front hook 68f and a rear hook 68r.

[0055] The main body 61 of the protective cover has a gas passage surface 61g, a reverse gas passage surface 61ag, a side surface 61s, and a cavity defining surface 62.

[0056] The gas passage surface 61g delineates a portion of the radially outer edge Dro of the annular combustion gas flow channel 39. The reverse gas passage surface 61ag faces the reverse gas passage side Dag, which is away from the combustion gas flow channel 39. The aforementioned gas passage surface 61g faces the gas passage side Dg, which is opposite to the reverse gas passage surface 61ag. Therefore, the gas passage surface 61g and the reverse gas passage surface 61ag are in a back-to-back relationship. In addition, in the state where the fixed blade 50 is mounted on the turbine housing 38 (refer to...), Figure 2 Under this condition, the gas passage side Dg in the outer shield 60o becomes the radially inner side Dri, and the reverse gas passage side Dag becomes the radially outer side Dro. When viewed from the gas passage side Dg or the reverse gas passage side Dag, the gas passage surface 61g and the reverse gas passage surface 61ag are parallelogram-shaped.

[0057] Side surface 61s is the surface connecting the edge of the gas passage surface 61g and the edge of the reverse gas passage surface 61ag. Therefore, side surface 61s extends from the edge of the gas passage surface 61g towards the reverse gas passage side Dag. This 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 within the combustion gas flow channel 39. In other words, the rear end surface 61sr faces the downstream side Dad of the axis. 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 upstream side Dau of the axis. The first side end surface 61s1 faces the first side Dc1 on the lateral Dc of the gas passage surface 61g and the rear end surface 61sr. This first side end surface 61s1 connects the edge of the first side Dc1 of the front end surface 61sf and the edge of the first side Dc1 of the rear end surface 61sr. The second side end face 61s2 faces the second side Dc2. This second side end face 61s2 connects the edge of the second side Dc2 of the front end face 61sf and the edge of the second side Dc2 of the rear end face 61sr. Additionally, in the state where the fixed blade 50 is mounted on the turbine housing 38 (see reference...) Figure 2 Under these conditions, the lateral DC becomes the circumferential DC.

[0058] The cavity defining surface 62 defines a cavity C through which cooling air Acl flows. This cavity C is a space recessed from the back gas passage surface 61ag towards the gas passage side Dg. 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 back gas passage side Dag and is located further towards the gas passage side Dg than the back gas passage surface 61ag. When viewed from the back gas passage side Dag, the bottom surface 62b, like the gas passage surface 61g, has a parallelogram shape. The front defining surface 62f faces the downstream side Dad and extends from the edge of the upstream side Dau of the bottom surface 62b towards the back gas passage 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 towards the back gas passage side Dag. A first side demarcation surface 62s1 faces the second side Dc2 and extends from the edge of the first side Dc1 on the bottom surface 62b towards the reverse gas passage side Dag. This first side demarcation surface 62s1 connects the edge of the first side Dc1 of the front demarcation surface 62f and the edge of the first side Dc1 of the rear demarcation surface 62r. ​​A second side demarcation surface 62s2 faces the first side Dc1 and extends from the edge of the second side Dc2 on the bottom surface 62b towards the reverse gas passage side Dag. This second side demarcation surface 62s2 connects the edge of the second side Dc2 of the front demarcation surface 62f and the edge of the second side Dc2 of the rear demarcation surface 62r.

[0059] The front hook 68f is formed to protrude from the anti-gas passage surface 61ag toward the anti-gas passage side Dag along the front end face 61sf. Furthermore, the rear hook 68r is formed to protrude from the anti-gas passage surface 61ag toward the anti-gas passage side Dag along the rear end face 61sr.

[0060] Both the front hook 68f and the rear hook 68r serve to install the fixed blade 50 onto the turbine housing 38.

[0061] like Figure 4 and Figure 6 As shown, the inner cover 60i has a cover body 61 and a retainer 69.

[0062] Similar to the outer shield 60o shield body 61, the shield body 61 has a gas passage surface 61g, a reverse gas passage surface 61ag, a side surface 61s, and a cavity defining surface 62.

[0063] The gas passage surface 61g delineates a portion of the radially inner edge Dri of the annular combustion gas flow channel 39. The reverse gas passage surface 61ag faces the reverse gas passage side Dag, which is away from the combustion gas flow channel 39. The aforementioned gas passage surface 61g faces the gas passage side Dg, which is opposite to the reverse gas passage surface 61ag. Furthermore, in the state where the fixed blade 50 is mounted on the turbine housing 38 (see reference...) Figure 2Under this condition, the gas passage side Dg in the inner shield 60i becomes the radially outer side Dro, and the reverse gas passage side Dag becomes the radially inner side Dri. When viewed from the gas passage side Dg or the reverse gas passage side Dag, the gas passage surface 61g and the reverse gas passage surface 61ag are parallelogram-shaped.

[0064] Side surface 61s is the surface connecting the edge of the gas passage surface 61g and the edge of the reverse gas passage surface 61ag. Therefore, side surface 61s extends from the edge of the gas passage surface 61g towards the reverse gas passage side Dag. Similar to the side surface 61s of the outer shield body 61 of the outer shield 60o, this 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 fuel gas flow within the combustion gas flow channel 39. In other words, the rear end surface 61sr faces the downstream side Dad of the axis. 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 upstream side Dau of the axis. The first side end surface 61s1 faces the first side Dc1 laterally on Dc. This first side end surface 61s1 connects the edge of the first side Dc1 of the front end surface 61sf and the edge of the first side Dc1 of the rear end surface 61sr. The second side end face 61s2 faces the second side Dc2 on the side of Dc. The second side end face 61s2 connects the edge of the second side Dc2 of the front end face 61sf and the edge of the second side Dc2 of the rear end face 61sr.

[0065] The cavity defining surface 62 defines the cavity C through which cooling air Acl flows. This cavity C is a space recessed from the reverse gas passage surface 61ag towards the gas passage side Dg. Similar to the cavity defining surface 62 of the outer casing 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 reverse gas passage side Dag and is located further towards the gas passage side Dg than the reverse gas passage surface 61ag. When viewed from the reverse gas passage side Dag, the bottom surface 62b, like the gas passage surface 61g, has a parallelogram shape. The front defining surface 62f faces the downstream side Dad and extends from the edge of the upstream side Dau of the bottom surface 62b towards the reverse gas passage side Dag. The rear demarcation surface 62r faces the upstream side Dau and extends from the edge of the downstream side Dad of the bottom surface 62b towards the reverse gas passage side Dag. The first side demarcation surface 62s1 faces the second side Dc2 and extends from the edge of the first side Dc1 of the bottom surface 62b towards the reverse gas passage side Dag. This first side demarcation surface 62s1 connects the edge of the first side Dc1 of the front demarcation surface 62f and the edge of the first side Dc1 of the rear demarcation surface 62r. ​​The second side demarcation surface 62s2 faces the first side Dc1 and extends from the edge of the second side Dc2 of the bottom surface 62b towards the reverse gas passage side Dag. This second side demarcation surface 62s2 connects the edge of the second side Dc2 of the front demarcation surface 62f and the edge of the second side Dc2 of the rear demarcation surface 62r.

[0066] The retainer 69 is located between the front end face 61sf and the rear end face 61sr, and extends from the first side end face 61s1 to the second side end face 61s2. This retainer 69 is connected to the inner cover 7 fixed to the gas turbine housing 8 (see reference). Figure 2 The radially outer end of the fixed blade 50, Dro, serves to support the radially inner portion of the fixed blade 50 on the inner cover 7.

[0067] like Figure 3 As shown, multiple blade air passages 56 extending radially Dr are formed on the blade body 51, the outer shroud 60o, and the inner shroud 60i. Each blade air passage 56 is continuously formed from the outer shroud 60o through the blade body 51 to the inner shroud 60i. The multiple blade air passages 56 are arranged along the arc CL of the blade body 51. A portion of adjacent blade air passages 56 communicates with each other in the radially outer Dro portion or the radially inner Dri portion. Furthermore, any one of the multiple blade air passages 56 opens on the bottom surface 62b of the cavity defining surface 62 in the outer shroud 60o. Alternatively, it is also possible for any one of the multiple blade air passages 56 to open on the bottom surface 62b of the cavity defining surface 62 in the inner shroud 60i.

[0068] Cooling air Acl flows into cavity C from the radially outer side Dro of outer shroud 60o. Additionally, cooling air Acl from the radially inner side Dri of cavity C of inner shroud 60i flows into cavity C. Alternatively, a portion of the cooling air Acl flowing into cavity C of outer shroud 60o may flow into cavity C of inner shroud 60i via any of the multiple blade air passages 56.

[0069] like Figure 5 As shown, the outer shield 60o has a cooling air passage 63 that allows cooling air Acl to flow into the cavity C of the outer shield 60o. 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 injection passages 65.

[0070] The first side channel 63a allows cooling air Acl to flow into the cavity C. This first side channel 63a has a front channel portion 63af and a first side channel portion 63a1. The front channel portion 63af opens onto the front defining surface 62f of the cavity defining surface 62. The front channel portion 63af extends from the opening of the front channel portion 63af towards the first side Dc1 between the front end face 61sf of the outer shield 60o and the front defining surface 62f of the cavity defining surface 62. The first side channel portion 63a1 extends along the first end face 61s1 between the first side end face 61s1 of the outer shield 60o and the first side defining surface 62s1 of the cavity defining surface 62. The upstream portion Dau of the first side channel portion 63a1 communicates with the front channel portion 63af. The first side channel portion 63a1 extends to the area between the rear end face 61sr of the outer shield 60o and the rear defining surface 62r of the cavity defining surface 62.

[0071] The second side channel 63b allows cooling air Acl to flow into the cavity C. This second side channel 63b has a front channel portion 63bf and a second side channel portion 63b2. The front channel portion 63bf opens onto the front defining surface 62f of the cavity defining surface 62. The front channel portion 63bf extends from the opening of the front channel portion 63bf towards the second side Dc2 between the front end face 61sf of the outer shield 60o and the front defining surface 62f of the cavity defining surface 62. The second side channel portion 63b2 extends along the second end face 61s2 between the second end face 61s2 of the outer shield 60o and the second side defining surface 62s2 of the cavity defining surface 62. A portion of the upstream side Dau of the second side channel portion 63b2 communicates with the front channel portion 63bf. The second side channel portion 63b2 extends between the rear end face 61sr of the outer protective cover 60o and the rear defining face 62r of the cavity defining face 62.

[0072] The rear end of the rear end channel 64 extends laterally Dc between the rear end face 61sr of the outer cover 60o and the rear defining face 62r of the cavity defining face 62. The first side Dc1 end of the rear end channel 64 communicates with the first side channel 63a. Furthermore, the second side Dc2 end of the rear end channel 64 communicates with the second side channel 63b.

[0073] Multiple rear-end injection channels 65 are connected to the rear-end channel 64 and open on the rear-end face 61sr of the outer shield 60o. The multiple rear-end injection channels 65 have multiple small rear-end injection channels 65s and multiple large rear-end injection channels 65l. The cross-sectional area of ​​each of the multiple large rear-end injection channels 65l is larger than the cross-sectional area of ​​any one of the multiple small rear-end injection channels 65s. Furthermore, the cross-sectional area here refers to the area on a section perpendicular to the direction of channel extension. The inner diameter of the small rear-end injection channels 65s is, for example, 1.0 mm, and the inner diameter of the large rear-end injection channels 65l is, for example, 2.0 mm.

[0074] The rear end face 61sr of the outer shield 60o has a central region A3 extending laterally to the center of Dc, a first side region A1 adjacent to the central region A3 and located on a first side Dc1 further than the central region A3, and a second side region A2 adjacent to the central region A3 and located on a second side Dc2 further than the central region A3. Each of the central region A3, the first side region A1, and the second side region A2 has a plurality of rear end injection channel openings 65.

[0075] In the central region A3 of the rear end face 61sr, the rear end injection small channel 65s and the rear end injection large channel 65l are alternately arranged and open on the lateral Dc. Therefore, in the outer shield 60o of this embodiment, the central region A3 is an alternating region A4.

[0076] Among the plurality of rear-end injection channels 65 opening in the first side region A1, the rear-end injection channel 65 located on the firstmost side Dc1, or the plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form the first-side rear-end injection channel 65c1. Furthermore, in this embodiment, the rear-end injection channel 65 located on the firstmost side Dc1 and the rear-end injection channel 65 adjacent to that rear-end injection channel 65, totaling two rear-end injection channels 65, form the first-side rear-end injection channel 65c1. Similarly, among the plurality of rear-end injection channels 65 opening in the second side region A2, the rear-end injection channel 65 located on the secondmost side Dc2, or the plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form the second-side rear-end injection channel 65c2. Furthermore, in this embodiment, the rear-end injection channel 65 located on the secondmost side Dc2 and the rear-end injection channel 65 adjacent to that rear-end injection channel 65, totaling two rear-end injection channels 65, form the second-side rear-end injection channel 65c2. Both the first rear-end injection channel 65c1 and the second rear-end injection channel 65c2 are large rear-end injection channels 65l.

[0077] Of the multiple rear-end injection channels 65 opening in the first side region A1, all of the rear-end injection channels 65 except for the first side rear-end injection channel 65c1 are rear-end injection sub-channels 65s. Furthermore, of the multiple rear-end injection channels 65 opening in the second side region A2, all of the rear-end injection channels 65 except for the second side rear-end injection channel 65c2 are rear-end injection sub-channels 65s.

[0078] The spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1 and the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2 are both narrower than the spacing P3 between adjacent channels in the lateral direction Dc of the plurality of rear-end injection channels 65s opening in the central region A3 (=alternating region A4) and the plurality of rear-end injection channels 65l. Furthermore, in this embodiment, the spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1 and the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2 are, for example, 10 times the inner diameter of the rear-end injection channels 65s (e.g., 1.0 mm), i.e., 10.0 mm. And the spacing P3 between the plurality of channels opening in the central region A3 (=alternating region A4) is, for example, 15 times the inner diameter of the rear-end injection channels 65s (e.g., 1.0 mm), i.e., 15.0 mm. Furthermore, the distance Pc between the two first-side rear-end injection channels 65c1 and the distance Pc between the two second-side rear-end injection channels 65c2 are, for example, 1.3 mm wider than the distances P1 and P2.

[0079] A portion of the cooling air Acl flowing into the cavity C of the outer shroud 60o flows into the first side channel 63a, and another portion flows into the second side channel 63b. The cooling air Acl flowing into the first side channel 63a flows within the first side channel 63a and into the rear end channel 64. The cooling air Acl flowing from the first side channel 63a into the rear end channel 64 flows towards the second side Dc2 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65. The cooling air Acl flowing into the second side channel 63b flows within the second side channel 63b and into the rear end channel 64. The cooling air Acl flowing from the second side channel 63b into the rear end channel 64 flows towards the first side Dc1 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65.

[0080] The cooling air Acl flowing within the cooling air passage 63 typically contains small amounts of foreign matter such as metal powder or dust. Therefore, if all the rear injection passages 65 are designed as small rear injection passages 65s, any of them is prone to blockage by foreign matter. If the rear injection passages 65 are blocked, the cooling effect near the blocked passage in the outer shroud 60o, which serves as the flow channel forming plate, is reduced, increasing the likelihood of thermal damage to the outer shroud 60o in the short term. Conversely, if all the rear injection passages 65 are designed as large rear injection passages 65l, the flow rate of cooling air Acl supplied to the outer shroud 60o, which serves as the flow channel forming plate, increases, reducing the efficiency of the gas turbine.

[0081] In this embodiment, the plurality of rear-end injection channels 65 opening at the rear end face 61sr have a plurality of small rear-end injection channels 65s and a plurality of large rear-end injection channels 65l. Therefore, in this embodiment, the possibility of all rear-end injection channels 65 being blocked by foreign objects can be reduced, the reduction in cooling effect caused by foreign object blockage can be suppressed, and thermal damage to the outer shroud 60o can be suppressed. In particular, in this embodiment, even if the small rear-end injection channels 65s in the alternating region A4 are blocked by foreign objects, the area including the area around the small rear-end injection channels 65s can be cooled by the cooling air Acl flowing in the large rear-end injection channel 65l adjacent to the small rear-end injection channel 65s. From this point of view, thermal damage to the outer shroud 60o can also be suppressed in this embodiment. Moreover, in this embodiment, since not all of the plurality of rear-end injection channels 65 opening at the rear end face 61sr are large rear-end injection channels 65l, the reduction in gas turbine efficiency caused by the increase in the flow rate of cooling air Acl supplied to the outer shroud 60o can be suppressed.

[0082] Foreign objects arriving at the first side Dc1 portion of the rear end channel 64 from the first side channel 63a will experience a greater inertial force towards the downstream side Dad compared to the cooling air Acl arriving at the first side Dc1 portion of the rear end channel 64 from the first side channel 63a. In this embodiment, the first side Dc1 portion of the rear end channel 64 is also connected to the rear end injection channel 65, so the possibility of foreign objects entering the rear end injection channel 65 is high. However, in this embodiment, among the multiple rear end injection channels 65 opening in the first side region A1, the two rear end injection channels 65 located at the first side Dc1 are the rear end injection large channels 65l, so even if foreign objects enter these rear end injection large channels 65l, the possibility of the foreign objects clogging the rear end injection large channels 65l is low. Furthermore, in this embodiment, the second side Dc2 portion of the rear end channel 64 is also connected to the rear end injection channel 65, so the possibility of foreign objects entering the rear end injection channel 65 is high. However, in this embodiment, among the multiple rear-end injection channels 65 that open in the second side region A2, the two rear-end injection channels 65 located on the secondmost side Dc2 are large rear-end injection channels 65l. Therefore, even if foreign objects enter these large rear-end injection channels 65l, the possibility of the foreign objects blocking the large rear-end injection channels 65l is low.

[0083] As described above, cooling air Acl flows from the first side channel 63a into the rear end channel 64 and flows toward the second side Dc2 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65. Therefore, the flow rate of cooling air Acl flowing from the first side channel 63a into the rear end channel 64 gradually decreases as it moves toward the second side Dc2. Consequently, the flow velocity of cooling air Acl flowing from the first side channel 63a into the rear end channel 64 gradually decreases as it moves toward the second side Dc2. Furthermore, as described above, cooling air Acl flows from the second side channel 63b into the rear end channel 64 and flows toward the first side Dc1 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65. Consequently, the flow rate of cooling air Acl flowing from the second side channel 63b into the rear end channel 64 gradually decreases as it moves toward the first side Dc1. Therefore, the flow velocity of cooling air Acl flowing from the second side channel 63b into the rear end channel 64 gradually decreases towards the first side Dc1. That is, in this embodiment, the flow velocity of cooling air Acl flowing from the rear end channel 64 into the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr is slower than the flow velocity of cooling air Acl flowing from the rear end channel 64 into the rear end injection channels 65 opening in the first side region A1 and the second side region A2 of the rear end face 61sr. Therefore, foreign objects are easily blocked in the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr. However, in this embodiment, since a portion of the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr is the rear end injection large channel 65l, the possibility of all the rear end injection channels 65 opening in the central region A3 of the rear end face 61sr being blocked by foreign objects is low.

[0084] As described above, in this embodiment, the rear-end injection channels 65 located in areas where foreign matter easily enters or in areas where foreign matter easily gets clogged are designated as large rear-end injection channels 65l. Therefore, in this embodiment, the possibility of the rear-end injection channels 65 located in areas where foreign matter easily enters or in areas where foreign matter easily gets clogged being blocked by foreign matter is low. Therefore, suppressing the reduction in cooling effect caused by foreign matter blockage in the rear-end injection channels 65 located in these areas can suppress thermal damage at the rear end of the outer shroud 60o. Conversely, in this embodiment, the rear-end injection channels 65 located in areas other than areas where foreign matter easily enters or gets clogged are designated as small rear-end injection channels 65s. Therefore, in this embodiment, the reduction in gas turbine efficiency caused by the increased flow rate of cooling air Acl supplied to the outer shroud 60o can be suppressed.

[0085] like Figure 6 As shown, similar to the outer shield 60o, the inner shield 60i also has a cooling air passage 63 that allows cooling air Acl to flow into the cavity C of the inner shield 60i. Similar to the cooling air passage 63 of the outer shield 60o, this cooling air passage 63 also has a first side passage 63a, a second side passage 63b, a rear end passage 64, and multiple rear end injection passages 65.

[0086] The first side channel 63a allows cooling air Acl to flow into the cavity C in the inner shield 60i. Similar to the first side channel 63a of the outer shield 60o, the first side channel 63a has a front channel portion 63af and a first side channel portion 63a1.

[0087] The second side channel 63b allows cooling air Acl to flow into the cavity C in the inner shield 60i. Similar to the second side channel 63b of the outer shield 60o, the second side channel 63b has a front channel portion 63bf and a second side channel portion 63b2.

[0088] The rear end of the rear end channel 64 extends laterally Dc between the rear end face 61sr of the inner protective cover 60i and the rear defining face 62r of the cavity defining face 62. The end of the first side Dc1 of the rear end channel 64 communicates with the first side channel 63a. Furthermore, the end of the second side Dc2 of the rear end channel 64 communicates with the second side channel 63b.

[0089] Similar to the multiple rear-end injection channels 65 of the outer shield 60o, the multiple rear-end injection channels 65 of the inner shield 60i also have multiple small rear-end injection channels 65s and multiple large rear-end injection channels 65l. Furthermore, similar to the inner diameter of the small rear-end injection channels 65s in the outer shield 60o, the inner diameter of the small rear-end injection channels 65s in the inner shield 60i is, for example, 1.0 mm. And similarly, similar to the inner diameter of the large rear-end injection channels 65l in the outer shield 60o, the inner diameter of the large rear-end injection channels 65l in the inner shield 60i is, for example, 2.0 mm.

[0090] In the central region A3 of the rear end face 61sr, the rear end injection small channel 65s and the rear end injection large channel 65l are alternately arranged and open on the lateral Dc. Therefore, in the inner shield 60i of this embodiment, the central region A3 is also an alternating region A4.

[0091] Among the plurality of rear-end injection channels 65 opening in the first side region A1, the rear-end injection channel 65 located on the firstmost side Dc1, or the plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form the first-side rear-end injection channel 65c1. Furthermore, in this embodiment, the rear-end injection channel 65 located on the firstmost side Dc1 and the rear-end injection channel 65 adjacent to that rear-end injection channel 65, totaling two rear-end injection channels 65, form the first-side rear-end injection channel 65c1. Similarly, among the plurality of rear-end injection channels 65 opening in the second side region A2, the rear-end injection channel 65 located on the secondmost side Dc2, or the plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form the second-side rear-end injection channel 65c2. Furthermore, in this embodiment, the rear-end injection channel 65 located on the secondmost side Dc2 and the rear-end injection channel 65 adjacent to that rear-end injection channel 65, totaling two rear-end injection channels 65, form the second-side rear-end injection channel 65c2. Both the first rear-end injection channel 65c1 and the second rear-end injection channel 65c2 are large rear-end injection channels 65l.

[0092] Of the multiple rear-end injection channels 65 opening in the first side region A1, all of the rear-end injection channels 65 except for the first side rear-end injection channel 65c1 are rear-end injection sub-channels 65s. Furthermore, of the multiple rear-end injection channels 65 opening in the second side region A2, all of the rear-end injection channels 65 except for the second side rear-end injection channel 65c2 are rear-end injection sub-channels 65s.

[0093] As described above, the arrangement of the plurality of rear-end injection small channels 65s and the plurality of rear-end injection large channels 65l in the inner shield 60i is basically the same as the arrangement of the plurality of rear-end injection small channels 65s and the plurality of rear-end injection large channels 65l in the aforementioned outer shield 60o.

[0094] Therefore, even in the inner shield 60i of this embodiment, similarly to the outer shield 60o described above, the possibility of all rear-end injection channels 65 being blocked by foreign objects can be reduced, the reduction in cooling effect caused by blockage by foreign objects can be suppressed, and thermal damage to the inner shield 60i can be suppressed. Moreover, even in the inner shield 60i of this embodiment, similarly to the outer shield 60o described above, since not all of the multiple rear-end injection channels 65 opening at the rear end face 61sr are large rear-end injection channels 65l, the reduction in gas turbine efficiency caused by the increase in the flow rate of cooling air Acl supplied to the inner shield 60i can be suppressed.

[0095] Furthermore, even in the inner shield 60i of this embodiment, similarly to the outer shield 60o described above, the rear-end injection channels 65 located in areas where foreign objects easily enter or in areas where foreign objects easily become clogged are designated as large rear-end injection channels 65l. Therefore, even in the inner shield 60i of this embodiment, similarly to the outer shield 60o described above, the rear-end injection channels 65 located in areas where foreign objects easily enter or in areas where foreign objects easily become clogged are less likely to be blocked by foreign objects. Therefore, the reduction in cooling effect caused by foreign object blockage in the rear-end injection channels 65 located in these areas is suppressed, thereby suppressing thermal damage at the rear end of the inner shield 60i.

[0096] In the inner shield 60i of this embodiment, the spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1, the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2, and the spacing P3 between adjacent channels in the lateral direction Dc of the plurality of rear-end injection channels 65s and the plurality of rear-end injection channels 65l opening in the central region A3 (=alternating region A4) are all the same. These spacings P1, P2, and Pc are all, for example, 7 times the inner diameter of the rear-end injection channel 65s (e.g., 1.0 mm), i.e., 7.0 mm. Furthermore, the spacing Pc between the two first-side rear-end injection channels 65c1 and the spacing Pc between the two second-side rear-end injection channels 65c2 are, for example, 1.3 mm wider than the spacings P1, P2, and P3. Therefore, in this embodiment, the minimum spacing between the plurality of rear-end injection channels 65 in the inner shield 60i is less than the minimum spacing between the plurality of rear-end injection channels 65 in the outer shield 60o, and the average spacing between the plurality of rear-end injection channels 65 in the inner shield 60i is less than the average spacing between the plurality of rear-end injection channels 65 in the outer shield 60o.

[0097] Furthermore, the size relationship of the spacings P1, P2, and P3 in the inner shield 60i can be the same as that in the aforementioned outer shield 60o. Conversely, the size relationship of the spacings P1, P2, and P3 in the aforementioned outer shield 60o can be the same as that in the inner shield 60i. Moreover, the minimum spacing between the plurality of rear-end injection channels 65 in the inner shield 60i is the same as the minimum spacing between the plurality of rear-end injection channels 65 in the outer shield 60o, and the average spacing between the plurality of rear-end injection channels 65 in the inner shield 60i is the same as the average spacing between the plurality of rear-end injection channels 65 in the outer shield 60o.

[0098] "Second Embodiment of Fixed Blades"

[0099] The second embodiment of the fixed blade will be described.

[0100] Similar to the fixed blade in the first embodiment, the fixed blade in this embodiment also has a blade body, an outer protective cover, and an inner protective cover.

[0101] like Figure 7 As shown, similar to the outer shield 60o in the first embodiment, the outer shield 60o of the fixed blade in this embodiment also has a cooling air passage 63A that allows cooling air Acl to flow into the cavity C of the outer shield 60o. This cooling air passage 63A has multiple rear-end injection passages 65A.

[0102] Similar to the plurality of rear-end injection channels 65 in the first embodiment, the plurality of rear-end injection channels 65A in this embodiment also have openings on the rear end face 61sr of the outer shroud 60o. Furthermore, similar to the plurality of rear-end injection channels 65 in the first embodiment, the plurality of rear-end injection channels 65A in this embodiment also have a plurality of small rear-end injection channels 65As and a plurality of large rear-end injection channels 65A1. However, each of the plurality of rear-end injection channels 65A in this embodiment also has an opening at the corner of the rear defining surface 62r in the cavity defining surface 62 or the bottom surface 62b in the cavity defining surface 62 and the rear defining surface 62r. ​​Therefore, unlike the plurality of rear-end injection channels 65 in the first embodiment, in the plurality of rear-end injection channels 65A in this embodiment, a portion of the cooling air Acl inside the cavity C flows in directly without passing through other cooling air channels.

[0103] Similar to the rear end face 61sr of the outer shield 60o in the first embodiment, the rear end face 61sr of the outer shield 60o has a central region A3, a first side region A1, and a second side region A2. In each of the central region A3, the first side region A1, and the second side region A2, there are a plurality of rear end injection channel 65A openings.

[0104] In the first side region A1 of the rear end face 61sr, there are two rear end injection channels 65A openings. Both of these rear end injection channels 65A are large rear end injection channels 65A1. In the second side region A2 of the rear end face 61sr, there are also two rear end injection channels 65A openings. Both of these rear end injection channels 65A are large rear end injection channels 65A1. Furthermore, in the central region A3 of the rear end face 61sr, there are also multiple rear end injection channels 65A openings. In this central region A3, the small rear end injection channels 65As and the large rear end injection channels 65A1 are alternately arranged and open in the lateral direction Dc. Therefore, in the outer shield 60o of this embodiment, the central region A3 of the rear end face 61sr is an alternating region A4. In addition, the number of rear end injection channels 65A opening in the first side region A1 and the number of rear end injection channels 65A opening in the second side region A2 can be more than three.

[0105] Furthermore, the spacing between the plurality of rear-end injection channels 65A opening in the central region A3 of the rear-end face 61sr, the spacing between the plurality of rear-end injection channels 65A opening in the first side region A1 of the rear-end face 61sr, and the spacing between the plurality of rear-end injection channels 65A opening in the second side region A2 of the rear-end face 61sr are all the same. However, in the outer shield 60o of this embodiment, similarly to the outer shield 60o of the first embodiment, the spacing between the plurality of rear-end injection channels 65A opening in the first side region A1 and the spacing between the plurality of rear-end injection channels 65A opening in the second side region A2 can be narrower than the spacing between the plurality of rear-end injection channels 65A opening in the central region A3.

[0106] In the outer shield 60o of this embodiment, the multiple rear injection channels 65A opening at the rear end face 61sr also have multiple small rear injection channels 65As and multiple large rear injection channels 65A1. Therefore, in this embodiment, the possibility of all rear injection channels 65A being blocked by foreign objects can be reduced, and the reduction in cooling effect caused by foreign object blockage can be suppressed, thereby suppressing thermal damage to the outer shield 60o. Moreover, in this embodiment, since not all of the multiple rear injection channels 65A opening at the rear end face 61sr are large rear injection channels 65A1, the reduction in gas turbine efficiency caused by the increase in the flow rate of cooling air Acl supplied to the outer shield 60o can be suppressed.

[0107] In this embodiment, even if a portion of the cooling air Acl within the cavity C flows directly into the multiple rear-end injection channels 65A without passing through other cooling air channels, foreign matter can easily flow into the multiple rear-end injection channels 65A located on the first side Dc1 and the second side Dc2 on the lateral Dc. This is because foreign matter tends to accumulate in the first side Dc1 portion and the second side Dc2 portion within the cavity C. In this embodiment, the multiple rear-end injection channels 65A on the first side Dc1 and the multiple rear-end injection channels 65A on the second side Dc2 are both large rear-end injection channels 65A1. Therefore, in this embodiment, the possibility of foreign matter easily flowing into the multiple rear-end injection channels 65A on the first side Dc1 and the multiple rear-end injection channels 65A on the second side Dc2 being blocked by foreign matter can be reduced.

[0108] Furthermore, while the structure of the outer shield 60o of the fixed blade in this embodiment has been described above, the inner shield of the fixed blade in this embodiment may also adopt the same structure as the outer shield 60o of the fixed blade in this embodiment. In this case, similarly to the fixed blade in the first embodiment, the minimum spacing between the plurality of rear-end injection channels in the inner shield is less than the minimum spacing between the plurality of rear-end injection channels 65A in the outer shield 60o, and the average spacing between the plurality of rear-end injection channels in the inner shield is less than the average spacing between the plurality of rear-end injection channels 65A in the outer shield 60o.

[0109] "Third Implementation Method of Fixed Blades"

[0110] A third embodiment of the fixed blade will be described.

[0111] Similar to the fixed blade in the first embodiment, the fixed blade in this embodiment also has a blade body, an outer protective cover, and an inner protective cover.

[0112] like Figure 8 As shown, similar to the outer shield 60o in the first embodiment, the outer shield 60o of the fixed blade in this embodiment also has a cooling air passage 63 that allows cooling air Acl to flow into the cavity C of the outer shield 60o. Similar to 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 injection passages 65.

[0113] The first side channel 63a allows cooling air Acl to flow into the cavity C. Similar to the first side channel 63a in the first embodiment, this first side channel 63a has a front channel portion 63af and a first side channel portion 63a1. The channel defining surface of the first side channel portion 63a1 of the first side channel 63a has a downstream defining surface 63a3 that defines the edge of the most downstream side Dad in the first side channel portion 63a1.

[0114] The second side channel 63b allows cooling air Acl to flow into the cavity C. Similar to the second side channel 63b in the first embodiment, this second side channel 63b has a front channel portion 63bf and a second side channel portion 63b2. The channel defining surface of the second side channel portion 63b2 of the second side channel 63b has a downstream defining surface 63b3 that defines the edge of the most downstream side Dad in the second side channel portion 63b2.

[0115] The rear end of the rear channel 64 extends laterally Dc between the rear end face 61sr of the outer cover 60o and the rear defining face 62r of the cavity defining face 62. The end of the first side Dc1 of the rear channel 64 communicates with the first side channel 63a. Furthermore, the end of the second side Dc2 of the rear channel 64 communicates with the second side channel 63b. The channel defining face of the rear channel 64 has a downstream defining face 64d3 that defines the edge of the most downstream side Dad of the rear channel 64.

[0116] In this embodiment, the downstream defining surface 63a3 of the first side channel 63a and the downstream defining surface 63b3 of the second side channel 63b are located further downstream than the downstream defining surface 64d3 of the rear channel 64. Therefore, in the first side channel 63a, a pocket portion 63a4 is formed further downstream than the position where it communicates with the rear channel 64. Similarly, in the second side channel 63b, a pocket portion 63b4 is formed further downstream than the position where it communicates with the rear channel 64.

[0117] In this embodiment, similarly to the first embodiment, the plurality of rear-end injection channels 65 have a plurality of small rear-end injection channels 65s and a plurality of large rear-end injection channels 65l. The cross-sectional area of ​​each of the plurality of large rear-end injection channels 65l is larger than the cross-sectional area of ​​any one of the plurality of small rear-end injection channels 65s.

[0118] In this embodiment, similarly to the first embodiment, the rear end face 61sr of the outer shield 60o has a central region A3 extending laterally to the center of Dc, a first side region A1 adjacent to the central region A3 and located further to the first side Dc1 than the central region A3, and a second side region A2 adjacent to the central region A3 and located further to the second side Dc2 than the central region A3. Each of the central region A3, the first side region A1, and the second side region A2 has a plurality of rear end injection channel 65 openings.

[0119] Multiple rear-end injection channels 65, which open in the central region A3 of the rear-end face 61sr, are all connected to the rear-end channel 64. In this central region A3, the small rear-end injection channels 65s and the large rear-end injection channels 65l are alternately arranged and open in the lateral direction Dc. Therefore, in the outer shield 60o of this embodiment, the central region A3 is also an alternating region A4.

[0120] Among the plurality of rear-end injection channels 65 opening in the first side region A1, the rear-end injection channel 65 located on the firstmost side Dc1, or a plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form a first-side rear-end injection channel 65c1. Furthermore, in this embodiment, the rear-end injection channel 65 located on the firstmost side Dc1 and the rear-end injection channel 65 adjacent to that rear-end injection channel 65, totaling two rear-end injection channels 65, also form a first-side rear-end injection channel 65c1. These first-side rear-end injection channels 65c1 open on the downstream side demarcation surface 63a3 of the first side channel 63a. And, among the plurality of rear-end injection channels 65 opening in the second side region A2, the rear-end injection channel 65 located on the secondmost side Dc2, or a plurality of rear-end injection channels 65 including one rear-end injection channel 65 and adjacent to each other, all form a second-side rear-end injection channel 65c2. Furthermore, in this embodiment, a rear-end injection channel 65 located on the second-most side Dc2 and a rear-end injection channel 65 adjacent to it, totaling two rear-end injection channels 65, also form a second-side rear-end injection channel 65c2. The second-side rear-end injection channel 65c2 opens on the downstream side defining surface 63b3 of the second-side channel 63b. Both the first-side rear-end injection channel 65c1 and the second-side rear-end injection channel 65c2 are large rear-end injection channels 65l.

[0121] Of the plurality of rear-end injection channels 65 opening in the first side region A1, all of the rear-end injection channels 65 except for the first side rear-end injection channel 65c1 are rear-end injection sub-channels 65s and are connected to the rear-end channel 64. Furthermore, of the plurality of rear-end injection channels 65 opening in the second side region A2, all of the rear-end injection channels 65 except for the second side rear-end injection channel 65c2 are rear-end injection sub-channels 65s and are connected to the rear-end channel 64.

[0122] The spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1 and the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2 are both narrower than the spacing P3 between adjacent channels in the lateral direction Dc of the plurality of rear-end injection channels 65s opening in the central region A3 (=alternating region A4) and the plurality of rear-end injection channels 65l. Furthermore, in this embodiment, the spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1 and the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2 are, for example, 10 times the inner diameter of the rear-end injection channels 65s (e.g., 1.0 mm), i.e., 10.0 mm. And the spacing P3 between the plurality of channels opening in the central region A3 (=alternating region A4) is, for example, 15 times the inner diameter of the rear-end injection channels 65s (e.g., 1.0 mm), i.e., 15.0 mm.

[0123] Similar to the first embodiment, a portion of the cooling air Acl flowing into the cavity C of the outer shroud 60o flows into the first side channel 63a, and another portion flows into the second side channel 63b.

[0124] Cooling air Acl flowing into the first side channel 63a flows downstream towards Dad within the first side channel portion 63a1 of the first side channel 63aa, then flows into the rear end channel 64, and flows towards the second side Dc2 within the rear end channel 64. Some foreign matter in the cooling air Acl flowing downstream towards Dad within the first side channel portion 63a1 does not flow into the rear end channel 64 with the cooling air Acl, but instead travels straight due to inertia and is captured by the pocket portion 63a4 of the first side channel portion 63a1. A portion of the foreign matter captured by the pocket portion 63a4 of the first side channel portion 63a1, along with the cooling air Acl, is ejected from the rear end face 61sr through the first side rear end injection channel 65c1, which opens at the downstream side demarcation surface 63a3 of the first side channel portion 63a1. This first side rear end injection channel 65c1 is a large rear end injection channel 65l, therefore the possibility of this channel being blocked by foreign matter is low.

[0125] As described above, in this embodiment, a portion of the foreign matter in the cooling air Acl flowing within the first side channel portion 63a1 is captured by the pocket portion 63a4 of the first side channel portion 63a1, thereby reducing the amount of foreign matter contained in the cooling air Acl flowing from the first side channel portion 63a1 into the rear end channel 64. Therefore, in this embodiment, the possibility of the plurality of rear end injection channels 65 communicating with the rear end channel 64 being blocked by foreign matter can be reduced.

[0126] Cooling air Acl flowing into the second side channel 63b flows downstream towards Dad within the second side channel portion 63b2 of the second side channel 63b, and then flows into the rear end channel 64, where it flows towards the second side Dc2. Some foreign matter in the cooling air Acl flowing downstream towards Dad within the second side channel portion 63b2 does not flow into the rear end channel 64 with the cooling air Acl, but instead travels straight due to inertia and is captured by the pocket portion 63b4 of the second side channel portion 63b2. A portion of the foreign matter captured by the pocket portion 63b4 of the second side channel portion 63b2, along with the cooling air Acl, is ejected from the rear end face 61sr via the second side rear end injection channel 65c2, which opens at the downstream side demarcation surface 63b3 of the second side rear end injection channel 63b2. This second side rear end injection channel 65c2 is a large rear end injection channel 65l, therefore the possibility of this channel being blocked by foreign matter is low.

[0127] As described above, in this embodiment, a portion of the foreign matter in the cooling air Acl flowing within the second side channel portion 63b2 is captured by the pocket portion 63b4 of the second side channel portion 63b2, thereby reducing the amount of foreign matter contained in the cooling air Acl flowing from the second side channel portion 63b2 into the rear end channel 64. Therefore, in this embodiment, the possibility of the plurality of rear end injection channels 65 communicating with the rear end channel 64 being blocked by foreign matter can be reduced.

[0128] Furthermore, the structure of the outer protective cover 60o of the fixed blade in this embodiment has been described above, but the inner protective cover of the fixed blade in this embodiment may also adopt the same structure as the outer protective cover 60o of the fixed blade in this embodiment.

[0129] "Implementation Method of the Segmentation Ring"

[0130] refer to Figure 9 An embodiment of the segmentation ring will be described.

[0131] The dividing ring 80 has a dividing ring body 81, a front hook 88f and a rear hook 88r.

[0132] Similar to the protective cover body 61 described above, the dividing ring body 81 has a gas passage surface 81g, a reverse gas passage surface 81ag, a side surface 81s, a cavity defining surface 82, and a cooling air passage 83.

[0133] The gas passage surface 81g is a portion of the edge of the radially outer Dro of the annular combustion gas flow channel 39, facing the gas passage side Dg. When viewed from the gas passage side Dg, this gas passage surface 81g has a quadrilateral shape. The reverse gas passage surface 81ag is back-to-back with the gas passage surface 81g and faces the reverse gas passage side Dag. Additionally, in the state where the dividing ring 80 is installed in the turbine housing 38 (see reference...). Figure 2 Under these conditions, the gas passage side Dg becomes the radially inner side Dri, and the reverse gas passage side Dag becomes the radially outer side Dro.

[0134] Side surface 81s is the surface connecting the edge of the gas passage surface 81g and the edge of the reverse gas passage surface 81ag. Therefore, side surface 81s extends from the edge of the gas passage surface 81g towards the reverse gas passage side Dag. This 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 within the combustion gas flow channel 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 the first side Dc1 along the lateral Dc of the gas passage surface 81g and the rear end surface 81sr. This first side end surface 81s1 connects the edge of the first side Dc1 of the front end surface 81sf and the 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 face 81s2 connects the edge of the second side Dc2 of the front end face 81sf and the edge of the second side Dc2 of the rear end face 81sr. Additionally, in the state where the dividing ring 80 is installed in the turbine housing 38 (see reference...). Figure 2 Under these conditions, the lateral DC becomes the circumferential DC.

[0135] The cavity defining surface 82 defines a cavity C through which cooling air Acl flows. This cavity C is a space recessed from the back gas passage surface 81ag towards the gas passage side Dg. The cavity defining surface 82 has 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 back gas passage side Dag and is located further towards the gas passage side Dg than the back gas passage surface 81ag. When viewed from the back gas passage side Dag, the bottom surface 82b, like the gas passage surface 81g, has a quadrilateral shape. The front defining surface 82f faces the downstream side Dad and extends from the edge of the upstream side Dau of the bottom surface 82b towards the back gas passage 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 towards the back gas passage side Dag. The first side demarcation surface 82s1 faces the second side Dc2 and extends from the edge of the first side Dc1 on the bottom surface 82b towards the reverse gas passage side Dag. This first side demarcation surface 82s1 connects the edge of the first side Dc1 of the front demarcation surface 82f and the edge of the first side Dc1 of the rear demarcation surface 82r. The second side demarcation surface 82s2 faces the first side Dc1 and extends from the edge of the second side Dc2 on the bottom surface 82b towards the reverse gas passage side Dag. This second side demarcation surface 82s2 connects the edge of the second side Dc2 of the front demarcation surface 82f and the edge of the second side Dc2 of the rear demarcation surface 82r.

[0136] The front hook 88f is formed to protrude along the front end face 81sf and from the reverse gas passage face 81ag toward the reverse gas passage side Dag. The rear hook 88r is formed to protrude along the rear end face 81sr and from the reverse gas passage face 81ag toward the reverse gas passage side Dag. Both the front hook 88f and the rear hook 88r serve to mount the dividing ring 80 onto the turbine housing.

[0137] The cooling air passage 83 has multiple rear-end injection passages 85. Each of the multiple rear-end injection 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 towards the gas passage side Dg from this opening towards the upstream side Dau. The main passage portion 85m starts from the end of the upstream side Dau of the front passage portion 85f, extends downstream towards the rear end surface 81sr of the dividing ring 80 between the gas passage surface 81g of the dividing ring 80 and the bottom surface 82b of the cavity defining surface 82, and opens at the rear end surface 81sr.

[0138] The multiple rear-end injection channels 85 have multiple small rear-end injection channels 85s and multiple large rear-end injection channels 85l. The cross-sectional area of ​​each of the multiple large rear-end injection channels 85l is larger than the cross-sectional area of ​​any one of the multiple small rear-end injection channels 85s.

[0139] In the first side region A1 of the rear end face 81sr, there are two rear end injection channels 85 openings. Both of these rear end injection channels 85 are large rear end injection channels 85l. In the second side region A2 of the rear end face 81sr, there are also two rear end injection channels 85 openings. Both of these rear end injection channels 85 are large rear end injection channels 85l. Furthermore, in the central region A3 of the rear end face 81sr, there are multiple rear end injection channels 85 openings. In this central region A3, small rear end injection channels 85s and large rear end injection channels 85l are alternately arranged and open in the lateral direction Dc. Therefore, in the segmented ring body 81 of this embodiment, the central region A3 of the rear end face 81sr is an alternating region A4. In addition, the number of rear end injection channels 85 opening in the first side region A1 and the number of rear end injection channels 85 opening in the second side region A2 can be 3 or more.

[0140] In the segmented ring 80 of this embodiment, the plurality of rear-end injection channels 85 opening at the rear end face 81sr also have a plurality of small rear-end injection channels 85s and a plurality of large rear-end injection channels 85l. Therefore, in this embodiment, the possibility of all rear-end injection channels 85 being blocked by foreign objects can be reduced, and the reduction in cooling effect caused by foreign object blockage can be suppressed, thereby suppressing thermal damage to the segmented ring 80. Moreover, in this embodiment, since not all of the plurality of rear-end injection channels 85 opening at the rear end face 81sr are large rear-end injection channels 85l, the reduction in gas turbine efficiency caused by the increase in the flow rate of cooling air Acl supplied to the segmented ring 80 can be suppressed.

[0141] Furthermore, in this embodiment, similar to the outer shield 60o in the second embodiment, the possibility of foreign objects easily flowing into the multiple rear-end injection channels 85 of the first side Dc1 and the multiple rear-end injection channels 85 of the second side Dc2 being blocked by foreign objects can be reduced.

[0142] "Variations"

[0143] This invention is not limited to the embodiments and variations described above. Various additions, modifications, substitutions, and partial deletions can be made without departing from the conceptual idea and spirit of the invention derived from the content specified in the patent claim and its equivalents.

[0144] "appendix"

[0145] The flow channel forming plate in the above embodiments can be understood as follows, for example.

[0146] (1) The flow channel forming plate in the first method has:

[0147] Gas passage surfaces 61g and 81g define a portion of the combustion gas flow channel 39 through which combustion gas G flows; side surfaces 61s and 81s extend from the edges of the gas passage surfaces 61g and 81g toward the reverse gas passage side Dag, away from the combustion gas flow channel 39; cavity defining surfaces 62 and 82 are recessed from the reverse gas passage side Dag toward the gas passage side Dg on the opposite side of the reverse gas passage side Dag, defining a cavity C through which cooling air Acl can flow; and cooling air channels 63, 63A, and 83 allow cooling air Acl to circulate within the cavity C. The side surfaces 61s and 81s have rear end surfaces 61sr and 81sr of the downstream side Dad of the fuel gas flowing within the combustion gas flow channel 39. The cooling air passages 63, 63A, and 83 have a plurality of rear-end injection passages 65, 65A, and 85 arranged laterally along the gas passage surfaces 61g and 81g and the rear-end surfaces 61sr and 81sr, and opening on the rear-end surfaces 61sr and 81sr. The plurality of rear-end injection passages 65, 65A, and 85 have a plurality of small rear-end injection passages 65s, 65As, and 85s and a plurality of large rear-end injection passages 65l, 65A1, and 85l. A portion of the large rear-end injection passages 65l, 65A1, and 85l are arranged adjacent to each other on the lateral Dc at the position closest to at least one of the first side Dc1 and the second side Dc2 on the lateral Dc. The cross-sectional area of ​​each of the plurality of large rear-end injection passages 65l, 65A1, and 85l is larger than the cross-sectional area of ​​any one of the plurality of small rear-end injection passages 65s, 65As, and 85s.

[0148] In this method, the multiple rear-end injection channels 65, 65A, 85 with openings on the rear end faces 61sr and 81sr have multiple small rear-end injection channels 65s, 65As, 85s and multiple large rear-end injection channels 65l, 65A1, 85l. Therefore, in this method, the possibility of all rear-end injection channels 65, 65A, 85 being blocked by foreign objects can be reduced, and the reduction in cooling effect caused by foreign object blockage can be suppressed, thereby suppressing thermal damage to the flow channel forming plate. Furthermore, foreign objects can easily flow into the rear-end injection channels 65, 65A, 85 on the first side Dc1 and the second side Dc2 of the lateral Dc. In this method, the multiple rear-end injection channels 65, 65A, 85 located closest to one side of at least one of the first side Dc1 and the second side Dc2 are all large rear-end injection channels 65l, 65A1, 85l. Therefore, in this method, the possibility of the multiple rear-end injection channels 65, 65A, 85 on at least one side of the first side Dc1 and the second side Dc2 being blocked by foreign objects can be reduced. Furthermore, in this method, since not all of the multiple rear-end injection channels 65, 65A, 85 with openings on the rear end faces 61sr, 81sr are large rear-end injection channels 65l, 65A1, 85l, it is possible to suppress the decrease in gas turbine efficiency caused by the increase in the flow rate of cooling air Acl supplied to the flow channel forming plate.

[0149] (2) Flow channel forming plate in the second method

[0150] In the flow channel forming plate of the first method, in at least a portion of the lateral Dc region, namely the alternating region A4, the rear-end injection small channels 65s, 65As, 85s and the rear-end injection large channels 65l, 65A1, 85l are alternately arranged and open on the lateral Dc.

[0151] In this method, even if the rear-end injection channels 65s, 65As, and 85s of the alternating region A4 are blocked by foreign objects, the area surrounding the rear-end injection channels 65s, 65As, and 85s can be cooled by the cooling air Acl flowing in the rear-end injection channels 65l, 65Al, and 85l adjacent to the rear-end injection channels 65s, 65As, and 85s. From this perspective, thermal damage to the flow channel forming plate can also be suppressed in this method. Furthermore, since not all of the multiple rear-end injection channels 65, 65A, and 85 opening at the rear-end faces 61sr and 81sr are rear-end injection channels 65l, 65Al, and 85l, the decrease in gas turbine efficiency caused by the increased flow rate of cooling air Acl supplied to the flow channel forming plate can be suppressed in this method.

[0152] (3) Flow channel forming plate in the third method

[0153] In the flow channel forming plate of the second method, the side surface 61s has: a first side end face 61s1 facing the first side Dc1, and the end of the downstream side Dad is connected to the rear end face 61sr; and a second side end face 61s2 facing the second side Dc2, and the end of the downstream side Dad is connected to the rear end face 61sr. The cooling air passage 63 includes: a first side passage 63a, allowing cooling air Acl to flow in from the cavity C, and having a portion extending between the cavity C and the first side end face 61s1 in a direction along the gas passage surface 61g and the first side end face 61s1; a second side passage 63b, allowing cooling air Acl to flow in from the cavity C, and having a portion extending between the cavity C and the second side end face 61s2 in a direction along the gas passage surface 61g and the second side end face 61s2; and a rear end passage 64, extending laterally Dc between the cavity C and the rear end face 61sr, communicating with the first side passage 63a at the first side Dc1 and with the second side passage 63b at the second side Dc2. At least a portion of the plurality of rear end injection passages 65 communicates with the rear end passage 64.

[0154] (4) Flow channel forming plate in the fourth method

[0155] In the flow channel forming plate of the third embodiment, the channel defining surface of the first side channel 63a has a downstream defining surface 63a3 that defines the edge of the most downstream side Dad in the first side channel 63a. The channel defining surface of the second side channel 63b has a downstream defining surface 63b3 that defines the edge of the most downstream side Dad in the second side channel 63b. The channel defining surface of the rear end channel 64 has a downstream defining surface 64d3 that defines the edge of the most downstream side Dad in the rear end channel 64. The downstream defining surface 63a3 of the first side channel 63a and the downstream defining surface 63b3 of the second side channel 63b are located closer to the downstream side Dad than the downstream defining surface 64d3 of the rear end channel 64.

[0156] In this configuration, a portion of the first side channel 63a further downstream of its connection point with the rear end channel 64 (Dad) forms a pocket portion 63a4. Similarly, a portion of the second side channel 63b further downstream of its connection point with the rear end channel 64 (Dad) forms a pocket portion 63b4. Therefore, in this configuration, a portion of the foreign matter in the cooling air Acl flowing within the first side channel 63a is captured by the pocket portion 63a4 of the first side channel 63a. Furthermore, in this configuration, a portion of the foreign matter in the cooling air Acl flowing within the second side channel 63b is captured by the pocket portion 63b4 of the second side channel 63b. Thus, in this configuration, the amount of foreign matter contained in the cooling air Acl flowing into the rear end channel 64 from both the first side channel 63a and the second side channel 63b can be reduced.

[0157] (5) Flow channel forming plate in the fifth method

[0158] In the flow channel forming plate of the fourth embodiment, a portion of the plurality of rear-end injection channels 65l opens at the downstream side defining surface 63a3 of the first side channel 63a. Another portion of the plurality of rear-end injection channels 65l opens at the downstream side defining surface 63b3 of the second side channel 63b.

[0159] In this method, a portion of the foreign matter captured by the pocket portion 63a4 of the first side channel 63a can be ejected to the outside along with the cooling air Acl via the rear large injection channel 65l. Furthermore, a portion of the foreign matter captured by the pocket portion 63b4 of the second side channel 63b can be ejected to the outside along with the cooling air Acl via the rear large injection channel 65l. The cross-sectional area of ​​these rear large injection channels 65l is larger than that of the rear small injection channels 65s, thus suppressing the possibility of these rear large injection channels 65l being blocked by foreign matter.

[0160] (6) Flow channel forming plate in the sixth method

[0161] In the flow channel forming plate of any of the third to fifth embodiments, the rear end face 61sr has a central region A3 including the center of the lateral Dc, a first side region A1 adjacent to the central region A3 and located further to the first side Dc1 than the central region A3, and a second side region A2 adjacent to the central region A3 and located further to the second side Dc2 than the central region A3. A portion of the plurality of rear end injection channels 65 opens into the central region A3 of the rear end face 61sr. Another portion of the plurality of rear end injection channels 65 opens into the first side region A1 of the rear end face 61sr. Yet another portion of the plurality of rear end injection channels 65 opens into the second side region A2 of the rear end face 61sr.

[0162] (7) Flow channel forming plate in the seventh method

[0163] In the flow channel forming plate of the sixth method, the alternating region A4 is the region that includes the central region A3.

[0164] In this configuration, cooling air Acl flows from the first side channel 63a into the rear end channel 64 and flows toward the second side Dc2 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65. Therefore, the flow rate of cooling air Acl flowing from the first side channel 63a into the rear end channel 64 gradually decreases as it moves toward the second side Dc2. Consequently, the flow velocity of cooling air Acl flowing from the first side channel 63a into the rear end channel 64 gradually decreases as it moves toward the second side Dc2. Furthermore, in this configuration, cooling air Acl flows from the second side channel 63b into the rear end channel 64 and flows toward the first side Dc1 within the rear end channel 64. During this process, the cooling air Acl is ejected from the rear end face 61sr via multiple rear end injection channels 65. Consequently, the flow rate of cooling air Acl flowing from the second side channel 63b into the rear end channel 64 gradually decreases as it moves toward the first side Dc1. Therefore, the flow velocity of cooling air Acl flowing from the second side channel 63b into the rear end channel 64 gradually decreases as it moves towards the first side Dc1. That is, in this configuration, the flow velocity of cooling air Acl flowing from the rear end channel 64 into the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr is slower than the flow velocity of cooling air Acl flowing from the rear end channel 64 into the rear end injection channels 65 opening in the first side region A1 and the second side region A2 of the rear end face 61sr. Therefore, foreign objects are easily blocked in the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr. However, in this configuration, since a portion of the rear end injection channel 65 opening in the central region A3 of the rear end face 61sr is the rear end injection large channel 65l, the possibility of all rear end injection channels 65 opening in the central region A3 of the rear end face 61sr being blocked by foreign objects can be reduced.

[0165] (8) Flow channel forming plate in the eighth method

[0166] In the flow channel forming plate of the sixth or seventh embodiment, one of the plurality of rear-end injection channels 65 opening in the first side region A1, located on the first side Dc1, or a plurality of rear-end injection channels 65 including the first rear-end injection channel 65 and adjacent to each other, forms a first-side rear-end injection channel 65c1. In the plurality of rear-end injection channels 65 opening in the second side region A2, one of the rear-end injection channels 65 located on the second side Dc2, or a plurality of rear-end injection channels 65 including the first rear-end injection channel 65 and adjacent to each other, forms a second-side rear-end injection channel 65c2. Both the first-side rear-end injection channel 65c1 and the second-side rear-end injection channel 65c2 are the rear-end injection large channel 65l.

[0167] Foreign objects arriving at the first side Dc1 portion of the rear end channel 64 from the first side channel 63a will experience a greater inertial force towards the downstream side Dad compared to the cooling air Acl arriving at the first side Dc1 portion of the rear end channel 64 from the first side channel 63a. In this configuration, the first side Dc1 portion of the rear end channel 64 is also connected to the rear end injection channel 65, thus increasing the likelihood of foreign objects entering the rear end injection channel 65. However, in this configuration, since one or more of the rear end injection channels 65 located at the firstmost side Dc1 among the multiple rear end injection channels 65 opening in the first side region A1 constitute the rear end injection large channel 65l, even if foreign objects enter one or more of the rear end injection channels 65 located at the firstmost side Dc1, the likelihood of one or more rear end injection channels 65 being blocked by foreign objects can be reduced. Furthermore, in this configuration, since the second side Dc2 portion of the rear end channel 64 is also connected to the rear end injection channel 65, the likelihood of foreign objects entering the rear end injection channel 65 is also high. However, in this method, since one or more of the rear-end injection channels located on the secondmost side Dc2 among the multiple rear-end injection channels that open in the second side region A2 are large rear-end injection channels 65l, even if foreign objects enter one or more of the rear-end injection channels 65 located on the firstmost side Dc1, the possibility of one or more rear-end injection channels 65 being blocked by foreign objects can be reduced.

[0168] (9) Flow channel forming plate in the ninth method

[0169] In the flow channel forming plate of the eighth embodiment, all rear-end injection channels 65 opening in the first side region A1, except for the first-side rear-end injection channel 65c1, are the rear-end injection sub-channels 65s. All rear-end injection channels 65 opening in the second side region A2, except for the second-side rear-end injection channel 65c2, are the rear-end injection sub-channels 65s.

[0170] In this method, the flow rate of cooling air Acl supplied to the flow channel forming plate can be suppressed.

[0171] (10) Flow channel forming plate in the tenth method

[0172] In the flow channel forming plate of the ninth embodiment, the spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1 and the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2 are narrower than the spacing P3 between the plurality of rear-end injection channels 65 opening in the central region A3.

[0173] (11) Flow channel forming plate in the eleventh method

[0174] In the flow channel forming plate of the ninth embodiment, the spacing P1 between the plurality of rear-end injection channels 65s opening in the first side region A1, the spacing P2 between the plurality of rear-end injection channels 65s opening in the second side region A2, and the spacing P3 between the plurality of rear-end injection channels 65 opening in the central region A3 are the same.

[0175] (12) Flow channel forming plate in the twelfth method

[0176] In the flow channel forming plate of the first method, the plurality of rear-end injection channels 65A and 85 are all opened on the cavity defining surfaces 62 and 82.

[0177] (13) Flow channel forming plate in the thirteenth method

[0178] In the flow channel forming plate of the twelfth embodiment, the area of ​​the rear end faces 61sr and 81sr, excluding the area where the plurality of rear end injection channels 65A and 85 open at the position closest to the at least one side, is an alternating region A4. In the alternating region A4, the small rear end injection channels 65As and 85s and the large rear end injection channels 65A1 and 85l are alternately arranged and open on the lateral Dc.

[0179] The fixed blades in the above embodiments can be understood as follows, for example.

[0180] (14) The fixed blade in the fourteenth method has:

[0181] The blade body 51 has a blade-shaped cross-section and extends along a blade height direction Dh having a directional component perpendicular to the cross-section; and an inner shield 60i and an outer shield 60o are connected to the blade body 51 and extend along a direction perpendicular to the blade height direction Dh. The inner shield 60i is connected to one side end of the blade body on one side and the other side on the blade height direction Dh. The outer shield 60o is connected to the other side end of the blade body. At least one of the inner shield 60i and the outer shield 60o is a flow channel forming plate of any of the first to the thirteenth embodiments.

[0182] In this method, thermal damage to at least one of the inner shield 60i and the outer shield 60o can be suppressed, while the flow rate of cooling air Acl supplied to the shield can be suppressed.

[0183] (15) The flow channel forming plate in the fifteenth method has:

[0184] The blade body 51 has a blade-shaped cross-section and extends along a blade height direction Dh having a directional component perpendicular to the cross-section; and an inner shield 60i and an outer shield 60o are connected to the blade body 51 and extend along a direction perpendicular to the blade height direction Dh. The inner shield 60i is connected to one side end of the blade body on one side and the other side on the blade height direction Dh. The outer shield 60o is connected to the other side end of the blade body. Both the inner shield 60i and the outer shield 60o are flow channel forming plates of any of the first to the thirteenth embodiments. The minimum spacing between the plurality of rear-end injection channels 65, 65A of the inner shield 60i is less than the minimum spacing between the plurality of rear-end injection channels 65, 65A of the outer shield 60o, and the average spacing between the plurality of rear-end injection channels 65, 65A of the inner shield 60i is less than the average spacing between the plurality of rear-end injection channels 65, 65A of the outer shield 60o.

[0185] In this method, thermal damage to the inner shield 60i and the outer shield 60o can be suppressed, and the flow rate of cooling air Acl supplied to these shields can be suppressed. Moreover, in this method, the cooling effect of the inner shield 60i is higher than that of the outer shield 60o.

[0186] The gas turbine in the above embodiments can be understood as follows, for example.

[0187] (16) The gas turbine in the sixteenth embodiment has

[0188] The turbine includes a flow channel forming plate, a turbine rotor 31 capable of rotating about an axis Ar, and a turbine housing 38 covering the flow channel forming plate and the turbine rotor 31. The turbine rotor 31 has: a plurality of rotating blade rows 33 arranged in an axial direction Da extending along the axis Ar; and a rotor shaft 32 on which the plurality of rotating blade rows 33 are mounted and extends along the axial direction Da about the axis Ar. The combustion gas flow channel 39 is a space within the turbine housing 38 that is annular on the outer periphery of the rotor shaft 32 and extends along the axial direction Da, about the axis Ar.

[0189] Industrial availability

[0190] According to one aspect of the present invention, thermal damage can be suppressed while the flow rate of cooling air is also suppressed.

[0191] Symbol Explanation

[0192] 1-Gas turbine rotor; 6-Intermediate casing; 7-Inner shroud; 8-Gas turbine casing; 10-Compressor; 11-Compressor rotor; 12-Rotor shaft; 13-Rotating blade row; 15-Fixed blade row; 18-Compressor casing; 20-Burner; 21-Burner injector; 22-Tail stack (or combustion chamber); 30-Turbine; 31-Turbine rotor; 32-Rotor shaft; 33-Rotating blade row; 35-Fixed blade row; 36-Fixed blade; 36b-Blade body; 36i-Inner shroud; 36o-Outer shroud; 37-Divider ring; 38-Turbine casing; 39-Combustion gas flow path; 50-Fixed blade; 51-Blade body; 52-Leading edge; 53-Trailback edge; 54-Negative pressure surface; 55-Positive pressure surface. 56-Blade air passage, 60i-Inner shroud, 60o-Outer shroud, 61-Shroud body, 61g-Gas passage surface, 61ag-Reverse gas passage surface, 61s-Side surface, 61sf-Front end face, 61sr-Rear end face, 61s1-First side end face, 61s2-Second side end face, 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 63b2 - Second side channel section, 63b3 - Downstream side defining surface, 63b4 - Pocket section, 64 - Rear end channel, 64d3 - Downstream side defining surface, 65, 65A - Rear end injection channel, 65s, 65As - Rear end injection small channel, 65l, 65Al - Rear end injection large channel, 65c1 - First side rear end injection channel, 65c2 - Second side rear end injection channel, 68f - Front hook, 68r - Rear hook, 69 - Cage, 80 - Dividing ring, 81 - Dividing ring body, 81g - Gas passage surface, 81ag - Reverse gas passage 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 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 injection passage, 85f-front side passage section, 85m-main passage section, 85s-rear end injection small passage, 85l-rear end injection large passage, 88f-front hook, 88r-rear hook, A-external 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-axis direction, Dau-upstream or upstream side of axis, Dad-downstream or downstream side of axisDc - circumferential or lateral, Dc1 - first side, Dc2 - second side, Dg - gas passage side, Dga - reverse gas passage side, Dh - blade height direction, Dr - radial, Dri - radially inward, Dro - radially outward.

Claims

1. A flow channel forming plate, comprising: Gas passage surface, which defines a portion of the combustion gas flow path; From the edge of the gas passage surface, it extends toward the reverse gas passage side away from the combustion gas flow channel; The cavity defining surface is recessed from the anti-gas passage side towards the gas passage side opposite to the anti-gas passage side, defining a cavity that allows cooling air to flow in; and The cooling air channel allows cooling air flowing into the cavity to circulate. The side has a rear end face facing downstream of the flow of fuel gas flowing within the combustion gas flow channel. The cooling air passage has multiple rear injection channels arranged laterally along the gas passage surface and the rear end surface, and opening at the rear end surface. The multiple rear-end injection channels have multiple small rear-end injection channels and multiple large rear-end injection channels. A portion of the plurality of rear-end injection channels are arranged adjacent to each other in the lateral direction at a position closest to said side on at least one of the first and second sides in the lateral direction. The cross-sectional area of ​​each of the multiple large rear-end injection channels is greater than the cross-sectional area of ​​any one of the multiple small rear-end injection channels.

2. The flow channel forming plate according to claim 1, wherein, In the rear end face, in at least a portion of the lateral region, i.e., the alternating region, the rear end injection small channel and the rear end injection large channel are alternately arranged and open in the lateral direction.

3. The flow channel forming plate according to claim 2, wherein, The side has: A first side end face, facing the first side, and the downstream end face connected to the rear end face; and The second side end face faces the second side, and the downstream end face is connected to the rear end face. The cooling air passage has: The first side channel allows cooling air to flow in from the cavity and has a portion extending between the cavity and the first side end face in a direction along the gas passage surface and the first side end face; The second side channel allows cooling air to flow in from the cavity and has a portion extending between the cavity and the second side end face in the direction along the gas passage surface and the second side end face; and A rear end channel extends laterally between the cavity and the rear end face, and communicates with a first side channel on the first side and a second side channel on the second side. At least a portion of the plurality of rear-end injection channels are connected to the rear-end channel.

4. The flow channel forming plate according to claim 3, wherein, The channel delineation surface defining the first side channel has a downstream delineation surface defining the edge of the most downstream side of the first side channel. The channel delineation surface defining the second side channel has a downstream delineation surface defining the edge of the most downstream side of the second side channel. The channel delineation surface defining the rear-end channel has a downstream delineation surface defining the most downstream edge of the rear-end channel. The downstream demarcation surface of the first side channel and the downstream demarcation surface of the second side channel are located further downstream than the downstream demarcation surface of the rear channel.

5. The flow channel forming plate according to claim 4, wherein, A portion of the multiple rear-end injection channels have an opening on the downstream side of the first side channel. Another portion of the multiple rear-end injection channels has an opening on the downstream side of the second side channel.

6. The flow channel forming plate according to claim 3, wherein, The rear end face has a central region including the lateral center, a first side region adjacent to the central region and located further to the first side than the central region, and a second side region adjacent to the central region and located further to the second side than the central region. A portion of the plurality of rear-end injection channels opens into the central region of the rear-end face. Another portion of the plurality of rear-end injection channels opens into the first side region of the rear-end face. Another portion of the plurality of rear-end injection channels opens in the second side region of the rear-end face.

7. The flow channel forming plate according to claim 6, wherein, The alternating region is the area that includes the central region.

8. The flow channel forming plate according to claim 6, wherein, In the plurality of rear-end injection channels that open in the first side region, the rear-end injection channel located on the far first side, or a plurality of rear-end injection channels including the first rear-end injection channel and adjacent to each other, all form the first-side rear-end injection channel. In the plurality of rear-end injection channels that open in the second side region, the rear-end injection channel located on the second-most side, or a plurality of rear-end injection channels including the aforementioned rear-end injection channel and adjacent to each other, all form the second-side rear-end injection channel. Both the first side rear-end injection channel and the second side rear-end injection channel are the rear-end injection large channels.

9. The flow channel forming plate according to claim 8, wherein, Of the plurality of rear-end injection channels that open in the first side region, all rear-end injection channels other than the first-side rear-end injection channel are the rear-end injection mini-channels. Of the plurality of rear-end injection channels that open in the second side region, all of the rear-end injection channels other than the second-side rear-end injection channels are the rear-end injection sub-channels.

10. The flow channel forming plate according to claim 9, wherein, The spacing between the plurality of rear-end injection channels opening in the first side region and the spacing between the plurality of rear-end injection channels opening in the second side region are narrower than the spacing between the plurality of rear-end injection channels opening in the central region.

11. The flow channel forming plate according to claim 9, wherein, The spacing between the plurality of rear-end injection channels opening in the first side region, the spacing between the plurality of rear-end injection channels opening in the second side region, and the spacing between the plurality of rear-end injection channels opening in the central region are all the same.

12. The flow channel forming plate according to claim 1, wherein, All of the multiple rear-end injection channels open on the cavity's defined surface.

13. The flow channel forming plate according to claim 12, wherein, In the rear end face, the area other than the area of ​​the plurality of rear end injection channel openings located closest to one side is an alternating area. In the alternating region, the small rear-end injection channel and the large rear-end injection channel are alternately arranged and open in the lateral direction.

14. A fixed blade, comprising: The blade has a blade-shaped cross-section and extends along a blade height direction having a component perpendicular to the cross-section; and The inner and outer protective covers are connected to the blade body and extend in a direction perpendicular to the height of the blade. The inner protective cover is connected to one end of the blade body on one side and the other side in the height direction of the blade. The outer protective cover is connected to the other end of the blade. At least one of the inner and outer shields is a flow channel forming plate as described in any one of claims 1 to 13.

15. A fixed blade, comprising: The blade has a blade-shaped cross-section and extends along a blade height direction having a component perpendicular to the cross-section; and The inner and outer protective covers are connected to the blade body and extend in a direction perpendicular to the height of the blade. The inner protective cover is connected to one end of the blade body on one side and the other side in the height direction of the blade. The outer protective cover is connected to the other end of the blade. Both the inner and outer protective covers are flow channel forming plates as described in any one of claims 1 to 13. The minimum spacing between the plurality of rear-end injection channels of the inner shield is less than the minimum spacing between the plurality of rear-end injection channels of the outer shield, and the average spacing between the plurality of rear-end injection channels of the inner shield is less than the average spacing between the plurality of rear-end injection channels of the outer shield.

16. A gas turbine comprising: The flow channel forming plate according to any one of claims 1 to 13; The turbine rotor is capable of rotating about its axis; and The turbine housing covers the flow channel forming plate and the turbine rotor. The turbine rotor has: Multiple rows of rotating blades are arranged along the axial direction extending from the said axis; and The rotor shaft is equipped with the plurality of rotating blade rows and extends along the axial direction with the axial axis as the center. The combustion gas flow channel is a space within the turbine housing that is annular on the outer periphery of the rotor shaft with the axis as the center and extends along the direction of the axis.

Images