Gas turbine stator blade and gas turbine

Abstract

This gas turbine stator blade is provided with: a passage that passes through the inside of a blade-shaped section so as to communicate an outer cavity formed on the outer side of an outer shroud in the height direction of the blade with an inner cavity formed on the inner side of an inner shroud in the height direction of the blade; a sealing tube disposed in the passage and configured to guide air in the outer cavity to the inner cavity; the fixing plate is arranged on the sealing pipe and is fixed on the outer side protective cover; and a heat insulation plate disposed on the outside of the fixed plate in the blade height direction and disposed so as to cover at least a portion of the outer shroud, the heat insulation plate satisfying B / A > = 0.40, where A is a projection area of the outer shroud projected on a plane orthogonal to the blade height direction, and B is a projection area of the heat insulation plate projected on a plane orthogonal to the blade height direction.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2022-114636 filed with the Japan Patent Office on July 19, 2022, and the contents of which are incorporated herein by reference. Background Art

[0003] The gas turbine described in Patent Document 1 describes the following: an outer cavity is formed between a gas turbine stator blade and a turbine casing, and cooling air guided to the outer cavity is guided to the inner peripheral side of the gas turbine stator blade (inner side in the radial direction of the gas turbine) through a pipe body arranged in a passage formed inside the gas turbine stator blade, and is used to cool the rotor shaft on the inner peripheral side of the gas turbine stator blade. In this structure, the cooling air is guided to the inner peripheral side of the gas turbine through the pipe body arranged in the inner passage of the gas turbine stator blade, so that the temperature rise of the cooling air due to convective heat transfer and radiation heat input from the wall surface of the inner passage of the gas turbine stator blade is suppressed by the pipe body, thereby suppressing the reduction of the cooling capacity of the cooling air.

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2017-187040 Summary of the invention

[0007] Technical issues to be solved by the invention

[0008] The gas turbine stator blade includes an outer shroud connected to the outer side of the blade profile in the blade height direction and an inner shroud connected to the inner side of the blade profile in the blade height direction. When the gas turbine is in operation, if the temperature of the cooling air in the outer cavity facing the outer shroud increases due to the heat input from the outer shroud, the cooling capacity of the cooling air will be reduced. Furthermore, when the gas turbine is in operation, if the temperature of the cooling air in the inner cavity facing the inner shroud increases due to the heat input from the inner shroud, the cooling capacity of the cooling air will be reduced. In this regard, Patent Document 1 does not disclose insights related to such a problem and its solution.

[0009] In view of the above circumstances, an object of at least one embodiment of the present invention is to provide a gas turbine stator blade and a gas turbine capable of suppressing a temperature increase of cooling air.

[0010] Means for solving technical problems

[0011] In order to achieve the above-mentioned object, a gas turbine stator blade according to at least one embodiment of the present invention includes:

[0012] Leaf type part;

[0013] An outer shroud connected to the outer side of the blade profile portion in the blade height direction;

[0014] An inner shroud connected to the inner side of the blade profile portion in a blade height direction;

[0015] a passage passing through the interior of the airfoil portion in a manner of communicating an outer cavity formed on the outer side of the outer shroud in the blade height direction with an inner cavity formed on the inner side of the inner shroud in the blade height direction;

[0016] a sealing tube disposed in the passage and configured to guide the air in the outer cavity to the inner cavity;

[0017] A fixing plate, mounted on the sealing tube and fixed to the outer shield; and

[0018] a heat shield plate arranged outside the fixing plate in the blade height direction and arranged to cover at least a portion of the outer shroud,

[0019] If the projection area of ​​the outer shroud on the plane perpendicular to the blade height direction is A, and the projection area of ​​the heat shield on the plane perpendicular to the blade height direction is B, then B / A≥0.40 is satisfied.

[0020] In order to achieve the above-mentioned object, a gas turbine stator blade according to at least one embodiment of the present invention includes:

[0021] Leaf type part;

[0022] An outer shroud connected to the outer end of the blade profile portion in the blade height direction;

[0023] An inner shroud connected to the inner end of the blade profile portion in the blade height direction;

[0024] a passage passing through the interior of the airfoil portion in a manner of communicating an outer cavity formed on the outer side of the outer shroud in the blade height direction with an inner cavity formed on the inner side of the inner shroud in the blade height direction;

[0025] a sealing tube disposed in the passage and configured to guide the air in the outer cavity to the inner cavity;

[0026] a fixing plate mounted on the sealing tube and fixed to the inner shield; and

[0027] The heat shield plate is disposed inside the fixing plate in the blade height direction and is disposed so as to cover at least a portion of the inner shroud.

[0028] In order to achieve the above-mentioned object, a gas turbine according to at least one embodiment of the present invention includes:

[0029] The above-mentioned gas turbine stator blades;

[0030] turbine rotor; and

[0031] The turbine housing accommodates the turbine rotor.

[0032] Effects of the Invention

[0033] According to at least one embodiment of the present invention, there are provided a gas turbine stator blade and a gas turbine capable of suppressing a temperature increase of cooling air. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a diagram showing a schematic configuration of a gas turbine 2 according to an embodiment.

[0035] Figure 2 This is a diagram showing an example of a cross section along the blade height direction in the turbine stator blade 12 of the gas turbine 2 .

[0036] Figure 3 It is magnified Figure 2 FIG. 1 is a diagram showing an outer end portion in a blade height direction in a cross section of a turbine stator blade 12 .

[0037] Figure 4 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0038] Figure 5 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0039] Figure 6 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0040] Figure 7 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0041] Figure 8 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0042] Fig. 9This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0043] Fig.10 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0044] Fig.11 This is a diagram of the outer shroud 22 of the turbine vane 12 as viewed from the outer side in the blade height direction in the blade height direction.

[0045] Fig.12 Yes means Figure 2 The diagram of the modified example of the turbine stationary blade 12 is a diagram showing another example of the cross section of the turbine stationary blade 12 along the blade height direction.

[0046] Fig.13 It is magnified Fig.12 The diagram shows an inner end portion of a turbine stator blade 12 in the blade height direction.

[0047] Fig.14 It is used to illustrate Fig.13 The diagram shows the structure of the inner end portion of the turbine stator blade 12 in the blade height direction. DETAILED DESCRIPTION

[0048] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described or illustrated in the embodiments are not intended to limit the scope of the invention, but are merely illustrative examples.

[0049] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" indicating relative or absolute configuration not only indicate such configuration in a strict sense, but also indicate a state of relative displacement at an angle or distance with a tolerance or a degree to which the same function can be achieved.

[0050] For example, expressions such as “identical”, “equal” and “homogeneous” that indicate that things are in the same state not only indicate the same state in a strict sense, but also indicate a state with tolerance or difference in the degree to which the same function can be obtained.

[0051] For example, expressions indicating shapes such as a quadrilateral and a cylinder not only indicate shapes such as a quadrilateral and a cylinder in a strict geometric sense, but also indicate shapes including concave and convex portions, chamfered portions, etc. within a range that can obtain the same effect.

[0052] On the other hand, the expression “have”, “complete”, “include”, “includes” or “has” a constituent element is not an exclusive expression that excludes the existence of other constituent elements.

[0053] Figure 1 This is a diagram showing a schematic configuration of a gas turbine 2 according to an embodiment.

[0054] like Figure 1 As shown, the gas turbine 2 includes a compressor 4 , a combustor 6 for mixing compressed air generated by the compressor 4 with fuel and burning the mixture, and a turbine 8 for obtaining power from the combustion gas generated by the combustor 6 .

[0055] like Figure 1 As shown, the turbine 8 includes a rotor 9 (turbine rotor), a turbine housing 10 accommodating the rotor 9, a plurality of turbine stator blades 12 (gas turbine stator blades) fixed to the inner surface of the turbine housing 10, and a plurality of turbine moving blades 16 implanted on the rotor 9 in a manner alternately arranged in the axial direction relative to the turbine stator blades 12. Hereinafter, unless otherwise specified, "circumferential direction" means the circumferential direction of the gas turbine 2, i.e., the circumferential direction of the rotor 9, "axial direction" means the axial direction of the gas turbine 2, i.e., the axial direction of the rotor 9, and "radial direction" means the radial direction of the gas turbine 2, i.e., the radial direction of the rotor 9.

[0056] Figure 2 This is a diagram showing an example of a cross section of the turbine stationary blade 12 along the blade height direction.

[0057] like Figure 2 As shown, the turbine stator blade 12 includes an airfoil portion 20, an outer shroud 22, an inner shroud 24, a passage 25, a sealing tube 26, a fixing plate 28, and a heat shield 30. In addition, in this specification, "blade height direction" refers to the blade height direction of the turbine stator blade 12, that is, the blade height direction of the airfoil portion 20, indicating the radial direction of the gas turbine 2.

[0058] The airfoil portion 20 has an airfoil cross-sectional shape defined by a pressure surface and a negative pressure surface, and a passage 25 is formed inside the airfoil portion 20 to connect an outer cavity 32 formed outside the outer shroud 22 in the blade height direction and an inner cavity 34 formed inside the inner shroud 24 in the blade height direction. The outer cavity 32 is formed between the outer shroud 22 and the turbine housing 10 (see Figure 1 ) between the inner and outer diaphragms, and the inner cavity 34 is a space formed between the inner shield 24 and the inner peripheral diaphragm 27.

[0059] The outer shroud 22 is connected to the outer end 20a of the airfoil portion 20 in the blade height direction, and is formed in a substantially plate shape along a surface intersecting the blade height direction. The outer shroud 22 forms the outer peripheral wall 33 of the flow path 31 of the combustion gas in the turbine 8 (the flow path of the main flow of the combustion gas in the turbine 8). The end surface 50 on the upstream side in the axial direction of the outer shroud 22 is formed with a hook 51 protruding toward the upstream side in the axial direction, and the end surface 52 on the downstream side in the axial direction of the outer shroud 22 is formed with a hook 53 protruding toward the downstream side in the axial direction. The turbine stator blade 12 is fixed to the turbine housing 10 by the hook 51 and the hook 53 respectively engaging with the groove (not shown) formed on the inner surface of the turbine housing 10. In addition, in this specification, "the upstream side in the axial direction" means the upstream side of the main flow of the combustion gas of the turbine 8 in the axial direction (the flow of the combustion gas flowing in the flow path 31), and "the downstream side in the axial direction" means the downstream side of the main flow of the combustion gas of the turbine 8 in the axial direction (the flow of the combustion gas flowing in the flow path 31).

[0060] The inner shroud 24 is connected to the inner end 20b of the airfoil 20 in the blade height direction, and is formed in a substantially plate-like shape along a surface intersecting the blade height direction. The inner shroud 24 forms an inner peripheral wall 35 of a flow path 31 (a flow path of the mainstream of the combustion gas in the turbine 8) of the combustion gas in the turbine 8. An annular inner peripheral side diaphragm 27 disposed on the inner peripheral side of the inner shroud 24 is fixed to the inner shroud 24.

[0061] The passage 25 passes through the interior of the airfoil portion 20 and communicates an outer cavity 32 formed on the outer side of the outer shroud 22 in the blade height direction with an inner cavity 34 formed on the inner side of the inner shroud 24 in the blade height direction. An inlet 36 of the passage 25 is formed on an outer wall surface 38 in the blade height direction of the outer shroud 22, and an outlet 40 of the passage 25 is formed on an inner wall surface 42 in the blade height direction of the inner shroud 24.

[0062] The sealing tube 26 is tubular and arranged in the direction in which the passage 25 extends (the axial direction of the passage 25) in the passage 25. The sealing tube 26 is configured to guide the air in the outer cavity 32 to the inner cavity 34 inside the inner shroud 24 in the blade height direction.

[0063] The compressed air from the compressor 4 is supplied to the outer cavity 32 as cooling air. The cooling air flowing from the outer cavity 32 into the sealing pipe 26 is supplied to the turbine stator blade 12 and the turbine moving blade 16 adjacent to the turbine stator blade 12 on the upstream side thereof (see FIG. Figure 1 ) between the stages 56 (wheel cavity) and acts as cooling air.

[0064] Figure 3It is magnified Figure 2 The diagram shows an outer end portion of a turbine stator blade 12 in the blade height direction.

[0065] like Figure 3 As shown in FIG. 1 , the fixing plate 28 is mounted on the outer peripheral surface 44 of the end portion 43 on the outer side in the blade height direction of the sealing tube 26 and fixed to the outer peripheral surface 44. The sealing tube 26 is provided to penetrate through the through hole 45 formed in the center of the fixing plate 28, and the outer peripheral surface 44 of the sealing tube 26 and the inner surface 46 of the through hole 45 are joined by welding or the like. The fixing plate 28 is arranged on the wall surface 38 on the outer side in the blade height direction of the outer shroud 22 and fixed to the wall surface 38 to close the portion on the outer side of the sealing tube 26 in the inlet 36 of the passage 25.

[0066] The heat shield 30 is arranged outside the fixed plate 28 in the blade height direction. The heat shield 30 is arranged with a gap between it and the fixed plate 28 in the blade height direction. In the example shown in the figure, the heat shield 30 includes: a plate-shaped top plate portion 60, which is arranged parallel to the wall surface 38 and the fixed plate 28 with gaps between it and the fixed plate 28 and the wall surface 38 in the blade height direction; and a side wall portion 62, which is connected to the peripheral edge 61 of the top plate portion 60 and is provided to surround the sealing tube 26 and the fixed plate 28. A gap g1 is provided between the heat shield 30 and the sealing tube 26. In the example shown in the figure, a through hole 64 is formed in the heat shield 30 for the sealing tube 26 to pass through, and a gap g1 is provided between the inner surface 65 of the through hole 64 and the outer peripheral surface 44 of the sealing tube 26 over the entire circumference of the sealing tube 26. Impingement cooling holes for impingement cooling the wall surface 38 of the outer shroud 22 are not formed in the heat shield 30. In addition, from the viewpoint of suppressing the temperature increase of the cooling air taken into the sealed tube 26, the outer end 26a of the sealed tube 26 in the blade height direction is preferably located at a position closer to the outside in the blade height direction than the insulation plate 30, but the outer end 26a of the sealed tube 26 may be located at the same position as the insulation plate 30 in the blade height direction or on the inner side of the insulation plate 30.

[0067] In the illustrated exemplary embodiment, a gap adjustment plate 66 is disposed on the heat insulating plate 30, and a through hole 67 is formed in the gap adjustment plate 66 for the sealing tube 26 to pass through. A gap g2 is provided over the entire circumference of the sealing tube 26 between the inner surface 68 of the through hole 67 and the outer peripheral surface 44 of the sealing tube 26. At each position on the outer peripheral surface 44 of the sealing tube 26, the gap g2 is smaller than the gap g1.

[0068] Figure 4 This is a diagram of a turbine stator blade 12 viewed from the outside in the blade height direction. Figure 4In the illustrated example, a pair of turbine blades 12 adjacent to each other in the circumferential direction share one outer shroud 22. That is, the airfoil portions 20 of a pair of turbine blades 12 adjacent to each other in the circumferential direction are connected to one outer shroud 22.

[0069] like Figure 3 and Figure 4 As shown in at least one of the foregoing, the outer shroud 22 includes a bottom plate portion 70 connected to the outer end 20a of the airfoil portion 20 in the blade height direction and a frame-shaped peripheral wall portion 72 formed along the peripheral edge 71 of the bottom plate portion 70 and protruding from the peripheral edge 71 to the outer side in the blade height direction. The bottom plate portion 70 is arranged to face the flow path 31 of the combustion gas in the turbine 8 (refer to Figure 2 ), and the outer peripheral wall 33 forms the flow path 31 of the combustion gas in the turbine 8 (the flow path of the mainstream of the combustion gas in the turbine 8). The peripheral wall portion 72 includes an upstream peripheral wall portion 72a extending in the circumferential direction along the end edge V1 on the upstream side in the axial direction of the peripheral edge 71 of the bottom plate portion 70, a downstream peripheral wall portion 72b extending in the circumferential direction along the end edge V2 on the downstream side in the axial direction of the peripheral edge 71 of the bottom plate portion 70, a one side peripheral wall portion 72c extending in a direction intersecting the circumferential direction along the end edge V3 on one side (pressure surface side) in the circumferential direction of the peripheral edge 71 of the bottom plate portion 70, and an other side peripheral wall portion 72d extending in a direction intersecting the circumferential direction along the end edge V4 on the other side (negative pressure surface side) in the circumferential direction of the peripheral edge 71 of the bottom plate portion 70. The hook 51 is provided to protrude from the axially upstream end surface 50 of the upstream peripheral wall portion 72a toward the axially upstream side, and the hook 53 is provided to protrude from the axially downstream end surface 52 of the downstream peripheral wall portion 72b toward the axially downstream side.

[0070] exist Figure 4 In the illustrated exemplary embodiment, the cross-sectional shape of each of the passage 25, the sealing tube 26 and the through hole 67 perpendicular to the blade height direction has a leaf shape, and the cross-sectional shape of each of the fixing plate 28 and the through hole 45 perpendicular to the blade height direction has a rounded rectangular (elliptical) shape. When viewed in the blade height direction, the peripheral edge 28a of the fixing plate 28 is located outside the passage 25, and the inner surface 45a of the through hole 45 of the fixing plate 28 is located inside the peripheral edge 66a of the gap adjustment plate 66 and outside the through hole 67 of the gap adjustment plate 66.

[0071] Figure 5 It is used to illustrate Figure 4 A diagram showing the relationship between the dimensions of the various parts.

[0072] exist Figure 5In the illustrated exemplary embodiment, the dimension L1 of the heat shield 30 in the axial direction is larger than the dimension C of the inlet 36 of the passage 25 in the axial direction. Furthermore, the dimension L1 of the heat shield 30 in the axial direction is larger than the dimension L2 of the fixing plate 28 in the axial direction. Furthermore, the distance d1 between the heat shield 30 in the axial direction and the upstream end 51a of the outer shroud 22 is smaller than the distance d2 between the inlet 36 of the passage 25 in the axial direction and the upstream end 51a of the outer shroud 22, and the distance d3 between the heat shield 30 in the axial direction and the downstream end 53a of the outer shroud 22 is smaller than the distance d4 between the inlet 36 in the axial direction and the downstream end 53a of the outer shroud 22. Furthermore, the axial distance d1 between the heat shield 30 and the upstream end 51a of the outer shield 22 is smaller than the axial distance d5 between the fixed plate 28 and the upstream end 51a of the outer shield 22, and the axial distance d3 between the heat shield 30 and the downstream end 53a of the outer shield 22 is smaller than the axial distance d6 between the fixed plate 28 and the downstream end 53a of the outer shield 22.

[0073] Here, regarding the use of Figure 2 to Figure 5 The turbine stator blade 12 to be described has a projection area (with the same Figure 6 The projection area corresponding to the shadow of the blade is set as A, and the projection area of ​​the heat insulation board 30 projected on the plane perpendicular to the blade height direction (corresponding to the shadow of the blade) is set as A. Figure 7 The projection area corresponding to the shadow of the image is set as B, then B / A≥0.40 is satisfied. The value of B divided by A can be greater than 0.40, preferably greater than 0.45, and more preferably greater than 0.50.

[0074] Next, the effects exerted by the turbine vane 12 will be described.

[0075] According to the turbine stator blade 12, the cooling air of the outer cavity 32 is guided to the inner cavity 34 through the inner side of the sealing tube 26 disposed in the passage 25 passing through the inside of the airfoil portion 20. Therefore, the sealing tube 26 suppresses the increase in the temperature of the cooling air passing through the inside of the sealing tube 26 due to convective heat transfer and radiation from the wall surface of the passage 25 inside the airfoil portion 20, thereby suppressing the reduction in the cooling capacity of the cooling air.

[0076] Furthermore, the heat shielding plate 30 disposed outside the fixing plate 28 in the blade height direction covers at least a portion of the outer shroud 22. If the projection area of ​​the outer shroud 22 projected on a plane perpendicular to the blade height direction is set to A, and the projection area of ​​the heat shielding plate 30 projected on a plane perpendicular to the blade height direction is set to B, then B / A ≥ 0.40 is satisfied. Therefore, the heat shielding plate 30 effectively suppresses the cooling air in the outer cavity 32 from rising due to the heat input from the outer shroud 22, thereby suppressing the temperature rise of the cooling air supplied to the turbine stator blade 12. As a result, compared with a structure without the heat shielding plate 30, a desired cooling effect can be obtained with a smaller amount of cooling air, or a higher cooling effect can be obtained with the same amount of cooling air.

[0077] Furthermore, according to the turbine vane 12, the space surrounded by the heat shield 30 and the outer shroud 22 communicates with the outer cavity 32 via the gap g1 provided between the heat shield 30 and the sealing tube 26, thereby suppressing the pressure difference between the two surfaces of the heat shield 30, thereby suppressing the heat shield 30 from falling off.

[0078] In some embodiments, for example, Figure 5 As shown, if the axial dimension of the inlet 36 of the passage 25 is set to C, the number of turbine vanes 12 connected to one outer shroud 22 is set to N, and the circumferential dimension in the outer shroud 22 is set to D, B ≥ C × D / N can be satisfied. That is, B can be a value greater than or equal to C multiplied by D divided by N. In addition, in the example shown in the figure, N is 2. Thus, the cooling air in the outer cavity 32 is effectively suppressed from rising due to the heat input from the outer shroud 22 by the heat insulation plate 30, so that the temperature rise of the cooling air supplied to the turbine vanes 12 can be suppressed.

[0079] In some embodiments, if the projected area of ​​the heat shield 30 on a plane perpendicular to the blade height direction ( Figure 7 The projection area corresponding to the shadow portion of the bottom plate portion 70 is set as B, and the portion 57 surrounded by the frame-shaped peripheral wall portion 72 in the bottom plate portion 70 (reference Figure 8 ) projected onto a plane perpendicular to the blade height direction (with Figure 8 The projection area corresponding to the shadow of the image is set to E, then B / E≥0.50. The value of B divided by E can be greater than 0.50, preferably greater than 0.55, and more preferably greater than 0.60.

[0080] The portion 57 of the bottom plate portion 70 surrounded by the peripheral wall portion 72 is thin and easily transfers heat, so it has a great influence on the amount of heat input of the cooling air from the outer shroud 22 to the outer cavity 32. Therefore, it is effective to provide the heat shield 30 in this portion. As described above, by satisfying B / E ≥ 0.50, the heat shield 30 effectively suppresses the cooling air in the outer cavity 32 from rising due to the heat input from the outer shroud 22, thereby suppressing the temperature rise of the cooling air supplied to the turbine stator blade 12.

[0081] In some embodiments, if the projected area of ​​the heat shield 30 on a plane perpendicular to the blade height direction ( Figure 7 The projection area corresponding to the shadow of the outer shield 22 is set as B, and the portion 58 (reference Fig. 9 In the example shown in the figure, the projection area (with the portion formed by the frame-shaped peripheral wall portion 72 and the bottom plate portion 70) projected onto a plane perpendicular to the blade height direction is Fig. 9 The area corresponding to the shaded portion of the image is set to F, then B / F≥0.45 is satisfied. The value of B divided by F can be greater than 0.45, preferably greater than 0.50, and more preferably greater than 0.55.

[0082] The hooks 51 and 53 in the outer shroud 22 for fixing the outer shroud 22 to the turbine housing 10 have little influence on the amount of heat input of the cooling air from the outer shroud 22 to the outer cavity 32. Therefore, as described above, by satisfying B / F ≥ 0.45, the heat shield 30 effectively suppresses the cooling air in the outer cavity 32 from rising due to the heat input from the outer shroud 22, thereby suppressing the temperature increase of the cooling air supplied to the turbine stator blades 12.

[0083] In some embodiments, for example, Fig.10As shown, in the peripheral edge 59 of the heat insulation plate 30, if the end edge on the upstream side in the axial direction is set as K1, the end edge on the downstream side in the axial direction is set as K2, the end edge on one side in the circumferential direction is set as K3, and the end edge on the other side in the circumferential direction is set as K4, then the turbine stator blade 12 may include a weld portion W1 along the end edge K1 to which the heat insulation plate 30 and the surface 38 of the outer shroud 22 are welded, a weld portion W2 along the end edge K2 to which the heat insulation plate 30 and the surface 38 of the outer shroud 22 are welded, a weld portion W3 along the end edge K3 to which the heat insulation plate 30 and the surface 38 of the outer shroud 22 are welded, and a weld portion W4 along the end edge K4 to which the heat insulation plate 30 and the surface 38 of the outer shroud 22 are welded. In the example shown in the figure, in the weld portion W1, the heat insulation board 30 and the surface 38 of the outer shield 22 are welded at multiple locations at intervals along the end edge K1, in the weld portion W2, the heat insulation board 30 and the surface 38 of the outer shield 22 are welded at multiple locations at intervals along the end edge K2, in the weld portion W3, the heat insulation board 30 and the surface 38 of the outer shield 22 are welded at multiple locations at intervals along the end edge K3, and in the weld portion W4, the heat insulation board 30 and the surface 38 of the outer shield 22 are welded at multiple locations at intervals along the end edge K4.

[0084] In this way, by providing the above-mentioned welding parts W1, W2, W3, and W4, not only can the insulation plate 30 be prevented from falling off, but also the cooling air in the outer cavity 32 can be prevented from passing between the peripheral edge 59 of the insulation plate 30 and the outer shield 22 and entering and exiting the gap between the insulation plate 30 and the outer shield 22, thereby preventing the temperature increase of the cooling air caused by the entry and exit.

[0085] In some embodiments, for example, Fig.11 As shown, in the peripheral edge 59 of the heat shield plate 30, if the upstream end edge in the axial direction is set as K1, the downstream end edge in the axial direction is set as K2, the one end edge in the circumferential direction is set as K3, and the other end edge in the circumferential direction is set as K4, the turbine stator blade 12 may not have a welded portion along the end edge K1 where the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded, and a welded portion along the end edge K2 where the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded. Fig.10 In the example shown, the turbine stator blade 12 includes a weld portion W3 where the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded along the edge K3, and a weld portion W4 where the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded along the edge K4. In the example shown, in the weld portion W3, the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded at multiple locations at intervals along the edge K3, and in the weld portion W4, the heat shield plate 30 and the surface 38 of the outer shroud 22 are welded at multiple locations at intervals along the edge K4.

[0086] The cooling air of the outer cavity 32 flows in the circumferential direction. Therefore, as described above, by providing a welding portion W3 at which the heat insulation plate 30 and the outer shield 22 are welded along one side end edge K3 of the circumferential direction of the peripheral edge 59 of the heat insulation plate 30 and a welding portion W4 at which the heat insulation plate 30 and the outer shield 22 are welded along the other side end edge K4 of the circumferential direction of the peripheral edge 59 of the heat insulation plate 30, the cooling air of the outer cavity 32 is prevented from passing between the peripheral edge 59 of the heat insulation plate 30 and the outer shield 22 and entering and exiting the gap between the heat insulation plate 30 and the outer shield, thereby suppressing the temperature increase of the cooling air caused by the entry and exit. Furthermore, there is no welding portion where the heat insulation plate 30 and the outer shroud 22 are welded at the end edge K1 on the upstream side in the axial direction along the peripheral edge 59 of the heat insulation plate 30, and there is no welding portion where the heat insulation plate 30 and the outer shroud 22 are welded at the end edge K2 on the downstream side in the axial direction along the peripheral edge 59 of the heat insulation plate 30, so that the labor and cost of welding can be reduced, and the temperature increase of the cooling air caused by the above-mentioned inflow and outflow can be suppressed.

[0087] Fig.12 Yes means Figure 2 The figure of the modification of the turbine stator blade 12 shown in FIG. 1 is a figure showing another example of the cross section of the turbine stator blade 12 along the blade height direction. In the turbine stator blade 12 described below, unless otherwise specified, Figure 2 The common symbols of the various structures of the turbine stator blade 12 are shown in FIG. Figure 2 The structures of the turbine stator blades 12 shown are the same structures, and the description thereof will be omitted.

[0088] exist Fig.12 In the exemplary embodiment of the present invention, the turbine stationary blade 12 includes a fixing plate 74 and a heat shield 76 fixed to the inner shroud 24. In addition, the turbine stationary blade 12 includes a cylindrical insert 48 inserted into the passage 25. The insert 48 includes an impingement cooling hole (not shown) penetrating the inner circumferential surface and the outer circumferential surface of the insert 48, and a gap is provided between the outer circumferential surface of the insert 48 and the inner surface of the airfoil portion 20 (the wall surface of the passage 25).

[0089] exist Fig.12 In the exemplary embodiment shown, the sealing tube 26 is arranged inside the insert 48 in the passage 25 along the direction in which the passage 25 extends (the axial direction of the passage 25). The sealing tube 26 is configured to guide the air of the outer cavity 32 to the inner cavity 34 inside the inner shroud 24 in the blade height direction.

[0090] The compressed air from the compressor 4 is supplied to the outer cavity 32 as cooling air. The cooling air flowing from the outer cavity 32 into the sealing pipe 26 is supplied to the turbine stator blade 12 and the turbine moving blade 16 adjacent to the turbine stator blade 12 on the upstream side thereof (see FIG. Figure 1) and functions as cooling air. The cooling air flowing from the outer cavity 32 into the inner side of the insert 48 is ejected onto the inner surface of the airfoil 20 from the impingement cooling holes (not shown) formed in the insert 48, and then flows out to the outer surface side of the airfoil 20 from the film cooling holes (not shown) formed in the airfoil 20.

[0091] Fig.13 It is magnified Fig.12 The diagram shows an inner end portion of a turbine stator blade 12 in the blade height direction.

[0092] like Fig.13 As shown in FIG. 1 , the fixing plate 74 is mounted on the outer peripheral surface 78 of the end portion 77 of the sealing tube 26 on the inner side in the blade height direction and fixed to the outer peripheral surface 78. The sealing tube 26 is provided to penetrate through a through hole 79 formed in the center of the fixing plate 74, and the outer peripheral surface 78 of the sealing tube 26 and the inner surface of the through hole 79 are joined by, for example, welding. The fixing plate 74 is arranged on the inner wall surface 80 of the inner shroud 24 on the inner side in the blade height direction and fixed to the wall surface 80 to close the outer portion of the sealing tube 26 in the outlet 40 of the passage 25.

[0093] The heat shield 76 is arranged inside the fixing plate 74 in the blade height direction (arranged inside the fixing plate 74 in the radial direction). The heat shield 76 is arranged to cover at least a portion of the fixing plate 74 with a gap therebetween in the blade height direction. In the illustrated example, the heat shield 76 is arranged parallel to the wall surface 80 and the fixing plate 74 with gaps therebetween in the blade height direction. A through hole 82 through which the sealing tube 26 passes is formed in the heat shield 76, and a gap g3 is provided over the entire circumference of the sealing tube 26 between the inner surface of the through hole 82 and the outer peripheral surface 78 of the sealing tube 26. In the illustrated exemplary embodiment, a step is formed in the blade height direction between the wall surface 80 to which the fixing plate 74 is fixed in the inner shroud 24 and the wall surface 81 to which the heat shield 76 is fixed in the inner shroud 24, and the wall surface 81 is located at a position further inside in the blade height direction than the wall surface 81.

[0094] In addition, no impingement cooling hole for impingement cooling the wall surface 80 of the inner shroud 24 is formed in the heat shield 76. In addition, in the illustrated structure, the inner end 26b of the sealing tube 26 in the blade height direction is located further inward in the blade height direction than the heat shield 76, but the inner end 26b of the sealing tube 26 may be located at the same position as the heat shield 76 in the blade height direction or outside the heat shield 76.

[0095] In the illustrated exemplary embodiment, a gap adjustment plate 83 is disposed on the heat insulating plate 76, and a through hole 84 is formed in the gap adjustment plate 83, through which the sealing tube 26 passes. A gap g4 is provided over the entire circumference of the sealing tube 26 between the inner surface of the through hole 84 and the outer peripheral surface 28 of the sealing tube 26. At each position on the outer peripheral surface 44 of the sealing tube 26, the gap g4 between the gap adjustment plate 83 and the outer peripheral surface 44 of the sealing tube 26 is smaller than the gap g3 between the heat insulating plate 76 and the outer peripheral surface 44 of the sealing tube 26.

[0096] Fig.14 It is used to illustrate Fig.13 The diagram shows the structure of the inner end portion of the turbine stator blade 12 in the blade height direction.

[0097] like Fig.14 As shown, the dimension L3 of the heat shield 76 in the axial direction is greater than the dimension E of the outlet 40 of the passage 25 in the axial direction. Furthermore, the dimension L3 of the heat shield 76 in the axial direction is greater than the dimension L4 of the fixing plate 28 in the axial direction. Furthermore, the distance d7 between the heat shield 76 in the axial direction and the upstream end 85a of the inner shroud 24 is smaller than the distance d8 between the outlet 40 of the passage 25 in the axial direction and the upstream end 85a of the inner shroud 24, and the distance d9 between the heat shield 76 in the axial direction and the downstream end 85b of the inner shroud 24 is smaller than the distance d10 between the outlet 40 in the axial direction and the downstream end 85b of the inner shroud 24. Furthermore, the axial distance d7 between the heat insulation plate 76 and the upstream end 85a of the inner shield 24 is smaller than the axial distance d11 between the fixed plate 74 and the upstream end 85a of the inner shield 24, and the axial distance d9 between the heat insulation plate 76 and the downstream end 85b of the inner shield 24 is smaller than the axial distance d12 between the fixed plate 74 and the downstream end 85b of the inner shield 24.

[0098] The following is the use of Figure 12 to Figure 14 The effects exerted by the turbine stator blade 12 described above will be described.

[0099] According to the turbine stator blade 12, the cooling air of the outer cavity 32 is guided to the inner cavity 34 through the inner side of the sealing tube 26 disposed in the passage 25 passing through the inside of the airfoil 20. Therefore, the temperature of the cooling air passing through the inner side of the sealing tube 26 is suppressed from rising due to convection heat transfer and radiation from the wall surface of the passage 25 inside the airfoil 20 and the inner surface of the insert 48, thereby suppressing the reduction in the cooling capacity of the cooling air. In addition, the fixing plate 74 can suppress the air used in cooling the airfoil 20 from leaking to the inner circumferential cavity 34 through the gap between the outer surface of the insert 48 and the inner surface of the airfoil 20.

[0100] Furthermore, the heat shielding plate 76 disposed inside the fixing plate 74 in the blade height direction (disposed inside the fixing plate 74 in the radial direction) covers at least a portion of the inner shroud 24, so that the cooling air in the inner cavity 34 is effectively suppressed from rising due to the heat input from the inner shroud 24 by the heat shielding plate 76, thereby suppressing the temperature rise of the cooling air supplied to the interstage space 56 (wheel cavity). As a result, compared with a structure without the heat shielding plate 76, a required cooling effect can be obtained with a smaller amount of cooling air, or a higher cooling effect can be obtained with the same amount of cooling air.

[0101] Furthermore, according to the above-mentioned turbine stator blade 12, the space surrounded by the heat insulation plate 76, the inner shroud 24 and the fixing plate 74 is connected to the inner cavity 34 via the gap g3 provided between the heat insulation plate 76 and the sealing tube 26, thereby suppressing the pressure difference between the two surfaces of the heat insulation plate 76, thereby suppressing the falling off of the heat insulation plate 76.

[0102] The present invention is not limited to the above-described embodiments, and includes modified embodiments of the above-described embodiments or appropriate combinations thereof.

[0103] The contents described in each of the above-mentioned embodiments can be understood, for example, as follows.

[0104] (1) A gas turbine stationary blade according to at least one embodiment of the present invention (for example, the above-mentioned turbine stationary blade 12) includes:

[0105] An airfoil portion (e.g., the airfoil portion 20 described above);

[0106] An outer shroud (e.g., the outer shroud 22 mentioned above), connected to the outer end of the blade profile portion in the blade height direction (e.g., the outer end 20a mentioned above);

[0107] An inner shroud (e.g., the inner shroud 24 mentioned above), connected to the inner end of the blade profile portion in the blade height direction (e.g., the inner end 20b mentioned above);

[0108] a passage (e.g., the passage 25) passing through the interior of the airfoil portion in a manner of communicating an outer cavity (e.g., the outer cavity 32) formed outside the outer shroud in the blade height direction with an inner cavity (e.g., the inner cavity 34) formed inside the inner shroud in the blade height direction;

[0109] a sealing tube (e.g., the sealing tube 26 described above), disposed in the passage and configured to guide the air in the outer cavity to the inner cavity;

[0110] A fixing plate (e.g., the fixing plate 28 mentioned above) mounted on the sealing tube and fixed to the outer shield; and

[0111] A heat shield (for example, the heat shield 30 described above) is arranged outside the fixing plate in the blade height direction and is arranged to cover at least a portion of the outer shroud.

[0112] When the projection area of ​​the outer shroud on the plane perpendicular to the blade height direction is set to A, and the projection area of ​​the heat shield on the plane perpendicular to the blade height direction is set to B, B / A≥0.40 is satisfied.

[0113] According to the gas turbine stator blade described in (1) above, the cooling air of the outer cavity is guided to the inner cavity through the inner side of the sealing tube arranged in the passage passing through the inner side of the blade profile, so that the temperature of the cooling air passing through the inner side of the sealing tube is suppressed by the sealing tube from rising due to convective heat transfer and radiation from the wall surface of the passage inside the blade profile, thereby suppressing the reduction of the cooling capacity of the cooling air. In addition, the heat shield plate arranged outside the fixing plate in the blade height direction covers at least a part of the outer shroud, and if the projected area of ​​the outer shroud projected on the plane orthogonal to the blade height direction is A, and the projected area of ​​the heat shield plate projected on the plane orthogonal to the blade height direction is B, then B / A≥0.40 is satisfied. Therefore, the cooling air of the outer cavity is effectively suppressed from rising due to the heat input from the outer shroud by the heat shield plate, thereby suppressing the temperature rise of the cooling air supplied to the gas turbine stator blade.

[0114] (2) In some embodiments, in the gas turbine stator blade described in (1) above, if the size of the entrance of the passage in the axial direction of the gas turbine is set to C, the number of gas turbine stator blades connected to the outer shroud is set to N, and the size of the outer shroud in the circumferential direction of the gas turbine is set to D, then B≥C×D / N is satisfied.

[0115] According to the gas turbine stator blade described in (2) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0116] (3) In some embodiments, in the gas turbine stator blade described in (1) or (2),

[0117] The outer shield comprises:

[0118] A bottom plate portion (e.g., the bottom plate portion 70 described above) connected to an outer end of the blade profile portion in a height direction of the blade; and

[0119] The peripheral wall portion (for example, the peripheral wall portion 72) is formed along the peripheral edge of the bottom plate portion (for example, the peripheral edge 71) and protrudes from the peripheral edge to the outside in the blade height direction.

[0120] The heat insulating plate is provided to cover at least a portion of the bottom plate portion surrounded by the peripheral wall portion (for example, the portion 57 described above),

[0121] If a projection area of ​​the portion of the bottom plate portion surrounded by the peripheral wall portion projected onto a plane orthogonal to the blade height direction is defined as E, B / E≥0.50 is satisfied.

[0122] The portion of the bottom plate surrounded by the peripheral wall portion is thin and easily transfers heat, so the heat input amount of the cooling air from the outer shroud to the outer cavity is greatly affected. Therefore, it is effective to provide a heat shield plate in the portion of the bottom plate surrounded by the peripheral wall portion. As described in (3) above, by satisfying B / E ≥ 0.50, the heat shield plate can effectively suppress the cooling air in the outer cavity from rising due to the heat input from the outer shroud, thereby suppressing the temperature rise of the cooling air supplied to the gas turbine stator blades.

[0123] (4) In some embodiments, in the gas turbine stator blade described in any one of (1) to (3),

[0124] If the projection area of ​​the portion of the outer shroud other than the hooks (for example, the hooks 51, 53) used to fix the outer shroud to the turbine casing (for example, the above-mentioned portion 58) projected onto a plane orthogonal to the blade height direction is set to F, B / F ≥ 0.45 is satisfied.

[0125] The hooks in the outer shroud for fixing the outer shroud to the turbine housing have little effect on the amount of heat input from the outer shroud to the cooling air in the outer cavity. Therefore, as described in (4) above, by satisfying B / F ≥ 0.45, the heat shield effectively suppresses the rise of the cooling air in the outer cavity due to the heat input from the outer shroud, thereby suppressing the temperature rise of the cooling air supplied to the gas turbine stator blades.

[0126] (5) In some embodiments, in the gas turbine stator blade described in any one of (1) to (4),

[0127] The dimension of the heat shield in the axial direction of the gas turbine (for example, the dimension L1 described above) is larger than the dimension of the inlet of the passage in the axial direction (for example, the dimension C described above).

[0128] According to the gas turbine stator blade described in (5) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0129] (6) In some embodiments, in the gas turbine stator blade described in any one of (1) to (5),

[0130] The dimension of the heat shield plate in the axial direction of the gas turbine (for example, the dimension L1 described above) is larger than the dimension of the fixing plate in the axial direction (for example, the dimension L2 described above).

[0131] According to the gas turbine stator blade described in (6) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0132] (7) In some embodiments, in the gas turbine stator blade described in any one of (1) to (6),

[0133] Regarding the heat shield, the distance between the heat shield and the upstream end of the outer shroud in the axial direction of the gas turbine (for example, the distance d1 mentioned above) is smaller than the distance between the entrance of the passage and the upstream end of the outer shroud in the axial direction (for example, the distance d2 mentioned above), and the distance between the heat shield and the downstream end of the outer shroud in the axial direction (for example, the distance d3 mentioned above) is smaller than the distance between the entrance and the downstream end of the outer shroud in the axial direction (for example, the distance d4 mentioned above).

[0134] According to the gas turbine stator blade described in (7) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0135] (8) In some embodiments, in the gas turbine stator blade described in any one of (1) to (7),

[0136] Regarding the heat shield, the distance between the heat shield and the upstream end of the outer shroud in the axial direction of the gas turbine (for example, the distance d1 mentioned above) is smaller than the distance between the fixed plate and the upstream end of the outer shroud in the axial direction (for example, the distance d5 mentioned above), and the distance between the heat shield and the downstream end of the outer shroud in the axial direction (for example, the distance d3 mentioned above) is smaller than the distance between the fixed plate and the downstream end of the outer shroud in the axial direction (for example, the distance d6 mentioned above).

[0137] According to the gas turbine stator blade described in (8) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0138] (9) In some embodiments, in the gas turbine stator blade described in any one of (1) to (8),

[0139] A gap (for example, the gap g1 described above) is provided between the heat insulating plate and the sealing tube.

[0140] According to the gas turbine stator blade described in (9) above, the space surrounded by the heat shield and the outer shroud communicates with the outer cavity via the gap provided between the heat shield and the sealing tube, thereby suppressing the pressure difference between the two surfaces of the heat shield, thereby suppressing the heat shield from falling off.

[0141] (10) In some embodiments, in the gas turbine stator blade described in any one of (1) to (9),

[0142] Impingement cooling holes for impingement cooling the outer shroud are not formed in the heat shield.

[0143] According to the gas turbine stator blade described in (10) above, the heat shield effectively suppresses the cooling air in the outer cavity from rising due to heat input from the outer shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0144] (11) In some embodiments, the gas turbine stator blade according to any one of (1) to (10) further comprises:

[0145] A welded portion (for example, the welded portion W1) is welded to the heat shield and the outer shroud along an end edge (for example, the end edge K1) on the upstream side in the axial direction of the gas turbine among the periphery (for example, the periphery 59) of the heat shield;

[0146] A welding portion (for example, the welding portion W2) is welded to the heat shield and the outer shield along the end edge (for example, the end edge K2) on the downstream side in the axial direction of the peripheral edge of the heat shield;

[0147] a welding portion (for example, the welding portion W3) to which the heat shield and the outer shroud are welded along one end edge (for example, the end edge K3) of the periphery of the heat shield in the circumferential direction of the gas turbine; and

[0148] The heat shield plate and the outer shield are welded at a welded portion (for example, the welded portion W4 described above) along the other end edge in the circumferential direction of the periphery of the heat shield plate (for example, the end edge K4 described above).

[0149] According to the gas turbine stator blade described in (11) above, by having the above-mentioned welding parts, it is not only possible to suppress the detachment of the heat insulation plate, but also possible to suppress the cooling air in the outer cavity from passing between the periphery of the heat insulation plate and the outer shroud and entering and exiting the gap between the heat insulation plate and the outer shroud, thereby suppressing the temperature increase of the cooling air caused by the entry and exit.

[0150] (12) In some embodiments, in the gas turbine stator blade described in any one of (1) to (10) above, the following is not included:

[0151] a welded portion (e.g., the welded portion W1) where the heat shield and the outer shroud are welded along an end edge (e.g., the end edge K1) on the upstream side in the axial direction of the gas turbine among the periphery (e.g., the periphery 59) of the heat shield; and

[0152] The heat shield and the outer shroud are welded to a welded portion (for example, the welded portion W2) along an end edge (for example, the end edge K2) on the downstream side in the axial direction of the peripheral edge of the heat shield,

[0153] The gas turbine stator blade further comprises:

[0154] a welding portion (for example, the welding portion W3) to which the heat shield and the outer shroud are welded along one end edge (for example, the end edge K3) of the periphery of the heat shield in the circumferential direction of the gas turbine; and

[0155] The heat shield plate and the outer shield are welded at a welded portion (for example, the welded portion W4 described above) along the other end edge in the circumferential direction of the periphery of the heat shield plate (for example, the end edge K4 described above).

[0156] Since the cooling air in the outer cavity flows in the circumferential direction, as described in (12), by providing a welded portion where the heat insulation board and the outer shroud are welded along one end edge in the circumferential direction of the heat insulation board and a welded portion where the heat insulation board and the outer shroud are welded along the other end edge in the circumferential direction of the heat insulation board, the cooling air in the outer cavity is prevented from passing through the circumferential edge of the heat insulation board and the outer shroud and entering and exiting the gap between the heat insulation board and the outer shroud, thereby suppressing the temperature rise of the cooling air caused by the entry and exit. In addition, by not providing a welded portion where the heat insulation board and the outer shroud are welded along the end edge in the axial direction of the gas turbine of the heat insulation board and a welded portion where the heat insulation board and the outer shroud are welded along the end edge in the axial direction of the heat insulation board, the labor and cost of welding can be reduced, and the temperature rise of the cooling air caused by the entry and exit can be suppressed.

[0157] (13) A gas turbine stationary blade according to at least one embodiment of the present invention (for example, the above-mentioned turbine stationary blade 12) includes:

[0158] An airfoil portion (e.g., the airfoil portion 20 described above);

[0159] An outer shroud (e.g., the outer shroud 22 mentioned above), connected to the outer end of the blade profile portion in the blade height direction (e.g., the outer end 20a mentioned above);

[0160] An inner shroud (e.g., the inner shroud 24 mentioned above) connected to the inner end of the blade profile portion in the blade height direction (e.g., the inner end 20b mentioned above);

[0161] a passage (e.g., the passage 25) passing through the interior of the airfoil portion in a manner of communicating an outer cavity (e.g., the outer cavity 32) formed outside the outer shroud in the blade height direction with an inner cavity (e.g., the inner cavity 34) formed inside the inner shroud in the blade height direction;

[0162] a sealing tube (e.g., the sealing tube 26 described above), disposed in the passage and configured to guide the air in the outer cavity to the inner cavity;

[0163] A fixing plate (e.g., the fixing plate 74 described above) mounted on the sealing tube and fixed to the inner shield; and

[0164] A heat shield plate (for example, the heat shield plate 76 described above) is disposed inside the fixing plate in the blade height direction and is disposed so as to cover at least a portion of the inner shroud.

[0165] According to the gas turbine stator blade described in (13) above, the cooling air of the outer cavity is guided to the inner cavity through the inner side of the sealing tube arranged in the passage passing through the inner part of the blade profile. Therefore, the sealing tube suppresses the increase in the temperature of the cooling air passing through the inner side of the sealing tube due to convective heat transfer and radiation from the wall surface of the passage inside the blade profile, etc., thereby suppressing the reduction in the cooling capacity of the cooling air. In addition, the heat shield plate arranged on the inner side of the fixing plate in the blade height direction (arranged on the inner side of the fixing plate in the radial direction of the gas turbine) covers at least a part of the inner shroud, so that the heat shield plate effectively suppresses the increase in the temperature of the cooling air in the inner cavity due to the heat input from the inner shroud, thereby suppressing the increase in the temperature of the cooling air supplied to the disk cavity. As a result, compared with a structure without a heat shield plate, a desired cooling effect can be obtained with a smaller amount of cooling air, or a higher cooling effect can be obtained with the same amount of cooling air.

[0166] (14) In some embodiments, in the gas turbine stator blade described in (13) above,

[0167] The dimension of the heat shield in the axial direction of the gas turbine (for example, the dimension L3 described above) is larger than the dimension of the outlet of the passage in the axial direction (for example, the dimension E described above).

[0168] According to the gas turbine stator blade described in (14) above, the heat shield effectively suppresses the cooling air in the inner cavity from rising due to heat input from the inner shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0169] (15) In some embodiments, in the gas turbine stator blade described in (13) or (14),

[0170] The dimension of the heat shield plate in the axial direction of the gas turbine (for example, the dimension L3 described above) is larger than the dimension of the fixing plate in the axial direction (for example, the dimension L4 described above).

[0171] According to the gas turbine stator blade described in (15) above, the heat shield effectively suppresses the cooling air in the inner cavity from rising due to heat input from the inner shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0172] (16) In some embodiments, in the gas turbine stator blade described in any one of (13) to (15),

[0173] Regarding the heat shield, the distance between the heat shield and the upstream end of the inner shroud in the axial direction of the gas turbine (for example, the distance d7 mentioned above) is smaller than the distance between the outlet of the passage and the upstream end of the inner shroud in the axial direction (for example, the distance d8 mentioned above), and the distance between the heat shield and the downstream end of the inner shroud in the axial direction (for example, the distance d9 mentioned above) is smaller than the distance between the outlet and the downstream end of the inner shroud in the axial direction (for example, the distance d10 mentioned above).

[0174] According to the gas turbine stator blade described in (16) above, the heat shield effectively suppresses the cooling air in the inner cavity from rising due to heat input from the inner shroud, thereby suppressing a temperature increase of the cooling air supplied to the gas turbine stator blade.

[0175] (17) In some embodiments, in the gas turbine stator blade described in any one of (13) to (16),

[0176] Regarding the heat shield plate, the distance between the heat shield plate and the upstream end of the inner shroud in the axial direction of the gas turbine (for example, the distance d7 mentioned above) is smaller than the distance between the fixed plate and the upstream end of the inner shroud in the axial direction (for example, the distance d11 mentioned above), and the distance between the heat shield plate and the downstream end of the inner shroud in the axial direction (for example, the distance d9 mentioned above) is smaller than the distance between the fixed plate and the downstream end of the inner shroud in the axial direction (for example, the distance d12 mentioned above).

[0177] (18) In some embodiments, in the gas turbine stator blade described in any one of (13) to (17),

[0178] A gap (for example, the gap g3 mentioned above) is provided between the heat insulating plate and the sealing pipe.

[0179] According to the gas turbine stator blade described in (18) above, the space surrounded by the heat shield and the inner shroud is connected to the inner cavity via the gap provided between the heat shield and the sealing tube, thereby suppressing the pressure difference between the two surfaces of the heat shield, thereby suppressing the heat shield from falling off.

[0180] (19) A gas turbine according to at least one embodiment of the present invention includes:

[0181] The gas turbine stator blade according to any one of (1) to (18) above;

[0182] turbine rotor; and

[0183] The turbine housing accommodates the turbine rotor.

[0184] According to the gas turbine described in (19) above, it is equipped with the gas turbine stator blades described in any one of (1) to (18) above, so that the rise of cooling air due to heat input from the outer shroud or the inner shroud is effectively suppressed by the heat insulation plate, thereby suppressing the temperature rise of the cooling air supplied to the gas turbine stator blades.

[0185] Explanation of symbols

[0186] 2-gas turbine, 4-compressor, 6-combustor, 8-turbine, 9-rotor (turbine rotor), 10-turbine housing, 12-turbine stator blades, 16-turbine moving blades, 20-blade profile, 20a-outer end, 20b-inner end, 22-outer shroud, 24-inner shroud, 25-channel, 26-sealing tube, 26a-outer end, 26b-inner end, 27-inner peripheral diaphragm, 28, 7 4-fixed plate, 28a, 59, 61, 66a, 71-periphery, 30, 6-insulation plate, 31-flow path, 32-outer cavity, 33-outer peripheral wall, 34-inner cavity, 35-inner peripheral wall, 36-inlet, 38, 42, 80, 81-wall surface, 40-outlet, 43, 77-end, 44, 78-outer peripheral surface, 45, 64, 67, 79, 82, 84-through hole, 45a , 46, 65, 68-inner surface, 50, 52-end surface, 51, 53-hook, 51a, 85a-upstream end, 53a, 85b-downstream end, 55-hole, 56-interstage space, 57, 58-part, 60-top plate, 62-side wall, 66, 83-gap adjustment plate, 70-bottom plate, 72-peripheral wall, 72a, 72b-upstream side peripheral wall, 72b-downstream side peripheral wall Part, 72c-one side peripheral wall portion, 72d-the other side peripheral wall portion, A, B, E, F-projection area, C, D-dimensions, K1, K2, K3, K4, V1, V2, V3, V4-end edges, W1, W2, W3, W4-welding portion, d1, d2, d3, d4, d5, d6, d7, d8, d9, d10, d11, d12-distances, g1, g2, g3, g4-gap.

Claims

1. A gas turbine stator blade, comprising: Leaf type part; An outer shroud connected to the outer end of the blade profile portion in the blade height direction; An inner shroud connected to the inner end of the blade profile portion in the blade height direction; a passage passing through the interior of the airfoil portion in a manner of communicating an outer cavity formed on the outer side of the outer shroud in the blade height direction with an inner cavity formed on the inner side of the inner shroud in the blade height direction; a sealing tube disposed in the passage and configured to guide the air in the outer cavity to the inner cavity; A fixing plate, mounted on the sealing tube and fixed to the outer shield; and a heat shield plate arranged outside the fixing plate in the blade height direction and arranged to cover at least a portion of the outer shroud, If the projection area of ​​the outer shroud on the plane perpendicular to the blade height direction is A, and the projection area of ​​the heat shield on the plane perpendicular to the blade height direction is B, then B / A≥0.40 is satisfied.

2. The gas turbine stator blade according to claim 1, wherein: If the size of the inlet of the passage in the axial direction of the gas turbine is set to C, the number of gas turbine stator blades connected to the outer shroud is set to N, and the size of the outer shroud in the circumferential direction of the gas turbine is set to D, then B≥C×D / N is satisfied.

3. The gas turbine stator blade according to claim 1, wherein: The outer shield comprises: a bottom plate portion connected to the outer side end of the blade profile portion in the blade height direction; and a peripheral wall portion formed along the peripheral edge of the bottom plate portion and protruding from the peripheral edge toward the outside in the blade height direction, The heat insulating plate is provided to cover at least a portion of the bottom plate portion surrounded by the peripheral wall portion. If a projection area of ​​the portion of the bottom plate portion surrounded by the peripheral wall portion projected onto a plane orthogonal to the blade height direction is defined as E, B / E≥0.50 is satisfied.

4. The gas turbine stator blade according to claim 1, wherein: If a projection area of ​​a portion of the outer shroud excluding hooks for fixing the outer shroud to the turbine housing, projected onto a plane perpendicular to the blade height direction, is denoted by F, B / F≥0.45 is satisfied.

5. The gas turbine stator blade according to claim 1, wherein: The size of the heat shield in the axial direction of the gas turbine is larger than the size of the inlet of the passage in the axial direction.

6. The gas turbine stator blade according to claim 1, wherein: The dimension of the heat shield plate in the axial direction of the gas turbine is larger than the dimension of the fixing plate in the axial direction.

7. The gas turbine stator blade according to claim 1, wherein: Regarding the heat shield, a distance between the heat shield and the upstream end of the outer shroud in the axial direction of the gas turbine is smaller than a distance between an inlet of the passage and the upstream end of the outer shroud in the axial direction, and a distance between the heat shield and the downstream end of the outer shroud in the axial direction is smaller than a distance between the inlet and the downstream end of the outer shroud in the axial direction.

8. The gas turbine stator blade according to claim 1, wherein: Regarding the heat shield plate, a distance between the heat shield plate and the upstream end of the outer shroud in the axial direction of the gas turbine is smaller than a distance between the fixed plate and the upstream end of the outer shroud in the axial direction, and a distance between the heat shield plate and the downstream end of the outer shroud in the axial direction is smaller than a distance between the fixed plate and the downstream end of the outer shroud in the axial direction.

9. The gas turbine stator blade according to claim 1, wherein: A gap is provided between the heat insulation plate and the sealing tube.

10. The gas turbine stator blade according to claim 1, wherein: Impingement cooling holes for impingement cooling the outer shroud are not formed in the heat shield.

11. The gas turbine stator blade according to claim 1, further comprising: a welding portion, wherein the heat shield plate and the outer shroud are welded along an end edge on an upstream side in the axial direction of the gas turbine among the peripheral edges of the heat shield plate; a welding portion, to which the heat shield and the outer shroud are welded along the downstream end edge of the peripheral edge of the heat shield in the axial direction; a welding portion, wherein the heat shield plate and the outer shroud are welded along one end edge of the periphery of the heat shield plate in the circumferential direction of the gas turbine; and The welding portion welds the heat shield and the outer shield along the other end edge in the circumferential direction of the peripheral edge of the heat shield.

12. The gas turbine stator blade according to claim 1, which does not include: a welding portion, wherein the heat shield plate and the outer shroud are welded along an end edge on an upstream side in the axial direction of the gas turbine among the peripheral edges of the heat shield plate; and a welding portion, wherein the heat shield and the outer shroud are welded along the downstream end edge in the axial direction of the peripheral edge of the heat shield, The gas turbine stator blade further comprises: a welding portion, wherein the heat shield plate and the outer shroud are welded along one end edge of the periphery of the heat shield plate in the circumferential direction of the gas turbine; and The welding portion welds the heat shield and the outer shield along the other end edge in the circumferential direction of the peripheral edge of the heat shield.

13. A gas turbine stator blade, comprising: Leaf type part; An outer shroud connected to the outer end of the blade profile portion in the blade height direction; An inner shroud connected to the inner end of the blade profile portion in the blade height direction; a passage passing through the interior of the airfoil portion in a manner of communicating an outer cavity formed on the outer side of the outer shroud in the blade height direction with an inner cavity formed on the inner side of the inner shroud in the blade height direction; a sealing tube disposed in the passage and configured to guide the air in the outer cavity to the inner cavity; a fixing plate mounted on the sealing tube and fixed to the inner shield; and The heat shield plate is disposed inside the fixing plate in the blade height direction and is disposed so as to cover at least a portion of the inner shroud.

14. The gas turbine stationary blade according to claim 13, wherein: The size of the heat shield in the axial direction of the gas turbine is larger than the size of the outlet of the passage in the axial direction.

15. The gas turbine stator blade according to claim 13, wherein: The dimension of the heat shield plate in the axial direction of the gas turbine is larger than the dimension of the fixing plate in the axial direction.

16. The gas turbine stationary blade according to claim 13, wherein: Regarding the heat shield, the distance between the heat shield and the upstream end of the inner shroud in the axial direction of the gas turbine is smaller than the distance between the outlet of the passage and the upstream end of the inner shroud in the axial direction, and the distance between the heat shield and the downstream end of the inner shroud in the axial direction is smaller than the distance between the outlet and the downstream end of the inner shroud in the axial direction.

17. The gas turbine stator blade according to claim 13, wherein: Regarding the heat shield plate, a distance between the heat shield plate and the upstream end of the inner shroud in the axial direction of the gas turbine is smaller than a distance between the fixed plate and the upstream end of the inner shroud in the axial direction, and a distance between the heat shield plate and the downstream end of the inner shroud in the axial direction is smaller than a distance between the fixed plate and the downstream end of the inner shroud in the axial direction.

18. The gas turbine stator blade according to claim 13, wherein: A gap is provided between the heat insulation plate and the sealing tube.

19. A gas turbine comprising: The gas turbine stator blade according to any one of claims 1 to 18; turbine rotor; and The turbine housing accommodates the turbine rotor.

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