Turbine stator blade, gas turbine, method for manufacturing turbine stator blade, and method for repairing turbine stator blade

Abstract

The invention provides a turbine stator blade, a gas turbine, a method for manufacturing the turbine stator blade, and a method for repairing the turbine stator blade. A turbine stator blade according to at least one embodiment of the present invention is provided with: an insert disposed in an inner space of a blade main body with a gap therebetween from an inner surface of the blade main body; an insert cover that blocks a gap between the inner surface of the blade body and the insert at one end of the insert, and that has an opening that communicates with the inner space of the insert; a closing plate extending in a direction orthogonal to the blade height direction on the opposite side of the insert cover in the blade height direction from the blade main body, and defining a first space communicating with the inner space of the insert via the opening of the insert cover; and an impact plate which fixes the outer side edge to the shield and the inner side edge to the insert cover so as to extend along the shield in the first space.

Description

Technical Field

[0001] This invention relates to turbine stationary blades, gas turbines, methods for manufacturing turbine stationary blades, and methods for repairing turbine stationary blades. Background Technology

[0002] A gas turbine includes a compressor that compresses atmosphere to generate compressed air, a combustor that burns fuel in the compressed air to generate combustion gases, and a turbine driven by the combustion gases. The turbine has a turbine rotor that rotates about an axis, multiple stationary blade stages arranged in an axial direction extending from the axis, and a turbine housing that rotatably covers the turbine rotor. The turbine rotor has a rotor shaft extending in an axial direction about the axis and multiple moving blade stages fixed to the rotor shaft. Each moving blade stage has multiple moving blades arranged circumferentially about the axis. One of multiple stationary blade stages is disposed upstream of the multiple moving blade stages. Each stationary blade stage has multiple stationary blades arranged circumferentially about the axis.

[0003] As a stationary blade, there is, for example, the stationary blade described in Patent Document 1. This stationary blade has a blade body extending radially relative to an axis, an outer shield formed on the radially outer side of the blade body, and an inner shield formed on the radially inner side of the blade body.

[0004] For example, in the stationary blade described in Patent Document 1, the cooling air for cooling the stationary blade is configured to be supplied to the stationary blade from both the inner shroud side and the outer shroud side. The cooling configuration of the inner shroud is to perform impact cooling by the cooling air supplied from the inner shroud side, and the cooling configuration of the outer shroud is to perform impact cooling by the cooling air supplied from the outer shroud side.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2010 / 131385 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, there are cases where, for certain reasons, it is necessary to limit the supply of cooling air for cooling the stationary blades to either the inner shroud side or the outer shroud side. In this case, in order to perform impact cooling on the shroud of the other side, it is necessary to be able to supply cooling air from either the inner or outer shroud side to the other side.

[0010] In view of the above, at least one embodiment of the present invention aims to provide a turbine stator blade, a gas turbine, a method for manufacturing a turbine stator blade, and a method for repairing a turbine stator blade capable of supplying cooling air from either the inner shroud side or the outer shroud side to the shroud of the other of the inner shroud side and the outer shroud side.

[0011] Solution for solving the problem

[0012] (1) The turbine stationary blade of at least one embodiment of the present invention comprises:

[0013] The hollow blade body extends along the height of the blade;

[0014] A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction;

[0015] An insert is disposed in the internal space of the blade body with a gap between it and the inner surface of the blade body;

[0016] An insert cover that seals the gap between the inner surface of the blade body and the insert at one end of the insert, and has an opening communicating with the inner space of the insert;

[0017] A sealing plate, which, on the side opposite to the blade body in the blade height direction, clamps the insert cover and extends in a direction orthogonal to the blade height direction, defining a first space communicating with the inner space of the insert through the opening of the insert cover; and

[0018] An impact plate, which secures its outer edge to the shield and its inner edge to the insert cover in such a manner that it extends along the shield within the first space.

[0019] (2) The gas turbine of at least one embodiment of the present invention comprises:

[0020] Compressor; and

[0021] A turbine having multiple turbine stationary blades of the structure described above (1).

[0022] (3) In the method for manufacturing turbine stationary blades according to at least one embodiment of the present invention,

[0023] The turbine stationary blades have:

[0024] The hollow blade body extends along the height of the blade;

[0025] A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction;

[0026] An insert is disposed in the internal space of the blade body with a gap between it and the inner surface of the blade body;

[0027] An insert cover that seals the gap between the inner surface of the blade body and the insert at one end of the insert, and has an opening communicating with the inner space of the insert;

[0028] A sealing plate, which, on the side opposite to the blade body in the blade height direction, clamps the insert cover and extends in a direction orthogonal to the blade height direction, defining a first space communicating with the inner space of the insert through the opening of the insert cover; and

[0029] An impact plate, which extends along the shield within the first space, secures its outer edge to the shield and its inner edge to the insert cover.

[0030] The method for manufacturing the turbine stationary blade includes:

[0031] The first assembly step involves fixing the insert cover to the blade body;

[0032] In the second assembly step, after performing the first assembly step, the outer edge of the impact plate is fixed to the protective cover, and the inner edge of the impact plate is fixed to the insert cover; and

[0033] The third assembly step involves setting up the enclosure plate in a manner that defines the first space after the second assembly step.

[0034] (4) In the method for repairing turbine stationary blades according to at least one embodiment of the present invention,

[0035] The turbine stationary blades have:

[0036] The hollow blade body extends along the height of the blade;

[0037] A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction;

[0038] An insert, which is spaced apart from the inner surface of the blade body and disposed within the internal space of the blade body; and

[0039] An insert cover, which is fixed to the blade body, seals the gap between the inner surface of the blade body and the insert at one end of the insert.

[0040] The repair method for the turbine stationary blades includes:

[0041] The first repair step involves providing a new insert cover with an opening communicating with the inner space of the insert;

[0042] The second repair step involves, after performing the first repair step, fixing the outer edge of the impact plate to the protective cover and fixing the inner edge of the impact plate to the new insert cover; and

[0043] In the third repair step, after the second repair step, a sealing plate is installed such that a first space is defined on the side opposite to the blade body, which is sandwiched between the new insert cover in the blade height direction, extending in a direction orthogonal to the blade height direction, and communicating with the inner space of the insert through the opening of the new insert cover.

[0044] In the first repair process, any of the following is performed:

[0045] The new insert cover is provided by forming the opening in the insert cover before repair, while the insert cover is fixed to the blade body.

[0046] The new insert cover is provided by fixing the insert cover to the blade body after the opening is formed in the insert cover before repair; and

[0047] The new insert cover is provided by fixing an insert cover with the opening, which is a component other than the insert cover before repair, to the blade body.

[0048] Invention Effects

[0049] According to at least one embodiment of the present invention, cooling air from either the inner shroud side or the outer shroud side can be supplied to the other shroud side of the turbine stationary blades. Attached Figure Description

[0050] Figure 1 This is a schematic diagram showing the overall structure of a gas turbine.

[0051] Figure 2 This is a cross-sectional view showing the gas flow path of the turbine.

[0052] Figure 3 This is a schematic front view showing several embodiments of the stationary blade.

[0053] Figure 4A This is a schematic diagram showing the inner shroud of several embodiments of the stationary blade viewed from the radial inside to the outside.

[0054] Figure 4B This is a schematic diagram showing the inner shroud of several embodiments of the stationary blade viewed from the radial inside to the outside, and showing the state with the shroud removed.

[0055] Figure 5 yes Figure 4A A schematic VV-direction sectional view, showing a cross section around the inner shroud of a stationary blade according to one embodiment.

[0056] Figure 6A This is a schematic cross-sectional view of the periphery of the inner shroud of a stator blade according to another embodiment, and is equivalent to... Figure 4A A schematic VV-direction sectional view.

[0057] Figure 6B This is a schematic cross-sectional view of the periphery of the inner shroud of a stator blade according to another embodiment, and is equivalent to... Figure 4A A schematic VV-direction sectional view.

[0058] Figure 7 It is used for explanation Figure 4B as well as Figure 5 The diagram shows the flow of cooling air in the stationary blades.

[0059] Figure 8 It is a schematic cross-sectional view of the stationary blades before the installation of the insert cover, impact plate, and closure plate.

[0060] Figure 9 It is a schematic cross-sectional view of the stationary blades before the installation of the impact plate and the sealing plate.

[0061] Figure 10 This is a schematic cross-sectional view of the stationary blades before the sealing plate is installed.

[0062] Figure 11 This is a schematic cross-sectional view of the previous stationary blades before repair.

[0063] Figure 12 This is a schematic cross-sectional view of the stationary blades during repairs before the installation of the impact plate and the sealing plate.

[0064] Explanation of reference numerals in the attached figures

[0065] 10 Gas turbine

[0066] 11 Compressor

[0067] 13 Turbo

[0068] 14 Rotors

[0069] 21. Turbine stationary blade (stationary blade)

[0070] 23. Blade body (blade shape)

[0071] 23i inner side

[0072] 23p end face

[0073] 24 Interior Space

[0074] 25 Inner Shield

[0075] 25b Inner surface

[0076] 27. Outer protective shield

[0077] 250 Inner protective cover main body

[0078] 310 Embedded component

[0079] 320 Insert Cover

[0080] 320X Previous insert cover

[0081] 321b end face

[0082] 323 Opening

[0083] 324 First end face

[0084] 325 Second end face

[0085] 331 First Space

[0086] 332 Second Space

[0087] 333 Third Space

[0088] 340 impact plate

[0089] 341 First Impact Plate

[0090] 342 Second Impact Plate

[0091] 344 Impact Hole

[0092] 345 Outer edge

[0093] 346 Inner edge

[0094] 346A First inner edge

[0095] 346B Second inner edge

[0096] 350 Closed panel. Detailed Implementation

[0097] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. The dimensions, materials, shapes, and relative arrangements of the constituent components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0098] For example, expressions such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" indicate not only a strict configuration, but also a state of relative displacement by angle or distance with tolerance or to the extent that the same function can be obtained.

[0099] For example, terms like "same," "equal," and "homogeneous" indicate that things are equal, not only in a strictly equal state, but also in a state where there is a tolerance or a difference in the degree to which they can achieve the same function.

[0100] For example, the representation of shapes such as quadrilaterals and cylinders not only refers to quadrilaterals and cylinders in a strict geometric sense, but also includes shapes with concave and convex parts, chamfered parts, etc., within the range where the same effect can be achieved.

[0101] On the other hand, expressions such as "possessing," "equipped with," "containing," "including," or "having" a constituent element are not exclusive expressions that exclude the existence of other constituent elements.

[0102] Figure 1 This is a schematic diagram showing the overall structure of the gas turbine. Figure 2 This is a cross-sectional view showing the gas flow path of the turbine.

[0103] In this embodiment, such as Figure 1 As shown, the gas turbine 10 is constructed by coaxially mounting a compressor 11, a burner 12, and a turbine 13 on a rotor 14, with a generator 15 connected to one end of the rotor 14. It should be noted that in the following description, as... Figure 2 As shown, the direction in which the axis Ax of the rotor 14 extends is defined as the axial direction Da, the circumferential direction centered on the axis Ax of the rotor 14 is defined as the circumferential direction Dc, and the direction perpendicular to the axis Ax of the rotor 14 is defined as the radial direction Dr. It should be noted that the radial direction Dr is also referred to as the blade height direction h.

[0104] Compressor 11 compresses air AI introduced from the air inlet through multiple stationary and moving blades to generate high-temperature, high-pressure compressed air AC. Combustor 12 supplies the compressed air AC with a specified amount of fuel FL and burns it to generate high-temperature, high-pressure combustion gas FG. Turbine 13 drives rotor 14 to rotate, thereby driving generator 15 connected to rotor 14, through multiple stationary and moving blades.

[0105] In addition, such as Figure 2 As shown, in the turbine 13, the turbine stationary blade (stationary blade) 21 is constructed by fixing the hub side (radially inner Dr) of the blade body (blade shape) 23 to the inner shroud 25 and the leading edge side (radially outer Dr) to the outer shroud 27. The turbine moving blade (moving blade) 41 is constructed by fixing the base end of the blade shape 43 to the flange 45. Furthermore, the outer shroud 27 and the dividing ring 51 disposed on the leading edge side of the moving blade 41 are supported in the turbine housing 30 via the heat insulation ring 53, and the inner shroud 25 is supported by the support ring 31. Therefore, the combustion gas flow path 32 through which the combustion gas FG passes is formed along the axial direction Da as a space surrounded by the inner shroud 25, the outer shroud 27, the flange 45, and the dividing ring 51.

[0106] It should be noted that the inner shield 25 and the outer shield 27 function as gas passage surface forming components. A gas passage surface forming component refers to a component that divides the combustion gas flow path 32 and has a gas passage surface in contact with the combustion gas FG.

[0107] The structure of the stationary blade 21, particularly the inner shield 25 and the parts near the inner shield 25, in several embodiments will be described below.

[0108] Figure 3 This is a schematic front view showing several embodiments of the stationary blade.

[0109] Figure 4A This is a schematic diagram showing the inner shroud of several embodiments of the stationary blades viewed from the inner side of the radial Dr towards the outer side.

[0110] Figure 4B This is a schematic diagram showing the inner shroud of the stationary blade in several embodiments viewed from the inner side of the radial Dr towards the outer side, and showing the state with the closure plate removed (described later).

[0111] Figure 5 yes Figure 4A A schematic VV-direction sectional view, showing a cross section around the inner shroud of a stationary blade according to one embodiment.

[0112] Figure 6A This is a schematic cross-sectional view of the periphery of the inner shroud of a stator blade according to another embodiment, and is equivalent to... Figure 4A A schematic VV-direction sectional view.

[0113] Figure 6B This is a schematic cross-sectional view of the periphery of the inner shroud of a stator blade according to another embodiment, and is equivalent to... Figure 4A A schematic VV-direction sectional view.

[0114] like Figure 3 As shown, in one embodiment, the stationary blade 21 is provided with an inner shield 25 at the end 23h (inner end of radial Dr) on the hub side of the blade-shaped portion 23, that is, on the side of the blade height direction h, and an outer shield 27 at the end 23c (outer end of radial Dr) on the front end side, that is, on the other side of the blade height direction h.

[0115] like Figure 3 , Figure 4A as well as Figure 4B As shown, in several embodiments of the stationary blade 21, the inner shield 25 has a plate-shaped inner shield body 250 extending along the circumferential direction Dc and the axial direction Da.

[0116] Several embodiments of the inner shield 25 have a pair of peripheral wall portions 251, the ends 25c of the pair of peripheral wall portions 251 on one side of the circumferential direction Dc in the inner shield body 250 extending along the extension direction of the end 25c and protruding from the inner surface 25b of the inner shield body 250 on the side opposite to the blade-shaped portion 23 in the blade height direction h (inner side of the radial Dr).

[0117] In one embodiment of the stationary blade 21, the inner shroud 25 includes a leading-edge retainer 61 and a trailing-edge retainer 63 extending radially inward in a direction opposite to the blade-shaped portion 23, sandwiching the gas passing surface 25a. The leading-edge retainer 61 is formed on the leading edge 23a side of the blade-shaped portion 23, and the trailing-edge retainer 63 is formed at a position closer to the trailing edge 23b side of the blade-shaped portion 23 than the leading-edge retainer 61. The leading-edge retainer 61 and the trailing-edge retainer 63 are connected by a support ring 31 (see reference 23). Figure 2 It is installed in the machine room 30.

[0118] The leading edge retainer 61 and the trailing edge retainer 63 extend circumferentially Dc and are connected to a pair of peripheral wall portions 251. They protrude from the inner shroud body 250 on the side opposite to the blade-shaped portion 23 (inner side of radial Dr) in the blade height direction h, and protrude beyond the pair of peripheral wall portions 251 on the opposite side (inner side of radial Dr) in the blade height direction h.

[0119] (Internal space 24 and insert 310)

[0120] In several embodiments, the blade-shaped portion 23 of the stationary blade 21 is provided with an internal space 24 extending along the blade height direction h. The internal space 24 is a through hole that penetrates the blade-shaped portion 23 along the blade height direction h. In several embodiments, the blade-shaped portion 23 of the stationary blade 21 is provided with multiple internal spaces 24.

[0121] In several embodiments, the stationary blade 21 has an insert 310 disposed in multiple internal spaces 24, spaced apart from the inner surface 23i of the blade-shaped portion 23. The insert 310 has a cylindrical shape with openings at both ends and is formed with multiple impact holes 311 extending along the thickness direction of the plate.

[0122] Although not illustrated, in several embodiments of the stationary blade 21, the insert 310 fixes the outer end of the radial Dr to the blade-shaped portion 23.

[0123] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, in several embodiments of the stationary blade 21, a plurality of film cooling holes 23f are formed in the blade-shaped portion 23, extending from the inner surface 23i to the outer surface 23s of the blade-shaped portion 23 and penetrating the blade-shaped portion 23 along the plate thickness direction.

[0124] Furthermore, in several embodiments of the stationary blade 21, the inner surface 23i of the blade-shaped portion 23 extends to a position closer to the inner side of the radially inner surface 25b of the inner shield body 250 than the radially inner surface 25b of the inner shield body 250. That is, the end face 23p of the inner side of the radially inner surface 23 of the blade-shaped portion 23 is located closer to the inner side of the radially inner surface 25b of the inner shield body 250 than the radially inner surface 25b of the inner shield body 250.

[0125] (Inset cover 320)

[0126] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, in several embodiments of the stationary blade 21, the insert 310 of the internal space 24L, which is disposed in a plurality of internal spaces 24 and is disposed at least on the side of the leading edge 23a of the blade-shaped portion 23, has an insert cover 320 fitted into the insert 310 at the end on the inner side of the radial Dr.

[0127] In several embodiments of the stationary blade 21, the insert cover 320 has: a plate-shaped flange portion 321; a protrusion 322 that protrudes from the flange portion 321 along the thickness direction of the flange portion 321 and is fitted into the insert 310 as described above; and an opening 323 that passes through the flange portion 321 and the protrusion 322 along the thickness direction of the flange portion 321.

[0128] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, the insert cover 320 is formed such that the protrusion 322 is fitted into the insert 310 when the outer end face 321a of the flange portion 321 in the radial direction Dr abuts the inner end face 23p of the blade-shaped portion 23 in the radial direction Dr. The flange portion 321 is fixed to the inner end face 23p of the blade-shaped portion 23 in the radial direction Dr, for example, by welding.

[0129] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, the insert cover 320 seals the gap between the inner surface 23i of the blade-shaped portion 23 and the insert 310 (the internal space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310) at the end of the insert 310 on the inner side of the radial Dr.

[0130] In addition, the opening 323 of the insert cover 320 is connected to the inner space 312 of the insert 310.

[0131] (Closed panel 350)

[0132] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, in several embodiments, the stationary blade 21 has an insert cover 320 sandwiched in the blade height direction h, and on the side opposite to the blade shape 23 (inner side of radial Dr), there is a closing plate 350 extending in a direction orthogonal to the blade height direction h. The closing plate 350 defines a first space 331 that communicates with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320.

[0133] The circumferential Dc end of the closure plate 350 is fixed to a pair of peripheral wall portions 251, for example by welding; the upstream end of the axial Da of the closure plate 350 is fixed to the leading edge retainer 61, for example by welding; and the downstream end of the axial Da is fixed to the trailing edge retainer 63, for example by welding.

[0134] exist Figure 5 as well as Figure 6A In the stationary blade 21 shown, the closing plate 350 is a plate component with a flat plate shape.

[0135] exist Figure 6B In the stationary blade 21 shown, a portion of the sealing plate 350A protrudes in the blade height direction h at a position opposite to the opening 323 of the insert cover 320, more than a pair of peripheral wall portions 251 toward one side of the blade height direction h (inner side of radial Dr).

[0136] It should be noted that the radial extension range of the first space 331 to the outer side of Dr is defined by the inner surface 25b of the inner shield body 250 to the inner side of Dr, and the radial extension range of the first space 331 to the inner side of Dr is defined by the closing plate 350. The circumferential extension range of the first space 331 to Dc is defined by a pair of peripheral wall portions 251, and the axial extension range of the first space 331 to the upstream side of Da is defined by the leading edge retainer 61.

[0137] The enclosure 350 separates the first space 331 from the space on the inner side of the enclosure 350, which is radially Dr.

[0138] (Impact plate 340)

[0139] like Figure 5 , Figure 6A ,as well as Figure 6B As shown, the stationary blade 21 in several embodiments includes an impact plate 340 that has an outer edge 345 fixed to the inner shield 25 and an inner edge 346 fixed to the insert cover 320 in a manner that extends along the inner shield body 250 within the first space 331.

[0140] exist Figure 5 , Figure 6A ,as well as Figure 6B In the stationary blade 21 shown, the outer edge 345 of the impact plate 340 is fixed to a pair of peripheral wall portions 251 and leading edge retainers 61, for example, by welding.

[0141] exist Figure 5 , Figure 6A ,as well as Figure 6B In the stationary blade 21 shown, the inner edge 346 of the impact plate 340 is fixed, for example, by welding to the end of the blade height direction h (inner side of radial Dr) in the insert cover 320, that is, the end face 321b of the flange portion 321 in the insert cover 320 on the inner side of radial Dr.

[0142] The impact plate 340 has a plurality of impact holes 344 that penetrate the impact plate 340 along the thickness direction of the impact plate 340.

[0143] It should be noted that, in Figure 4B In the design, impact holes 344 are described only in a portion of the impact plate 340, but impact holes 344 are provided throughout the entire impact plate 340.

[0144] Therefore, when cooling air is supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr) as described later, the cooling air from the inner space 312 of the insert 310 can flow into the first space 331 from the opening 323 of the insert cover 320. Thus, the cooling air supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr) can reach the inner shield 25.

[0145] The impact plate 340 is disposed between a second space 332 on one side (inner side of radial Dr) of the first space 331 in the blade height direction h and a third space 333 on the other side (outer side of radial Dr) of the first space 331 in the blade height direction h. The second space 332 communicates with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320. The third space 333 communicates with the second space 332 through a plurality of impact holes 344.

[0146] exist Figure 4B as well as Figure 5 In the stationary blade 21 shown, the impact plate 340 includes, for example, a first impact plate 341 disposed on the leading edge 23a side and a second impact plate 342 disposed on the trailing edge 23b side. The first impact plate 341 and the second impact plate 342 are joined together by welding.

[0147] exist Figure 6A as well as Figure 6B In the example shown, the impact plate 340 is a plate-shaped component.

[0148] It should be noted that, in Figure 6B In the stationary blade 21 shown, the impact plate 340 can also be as follows: Figure 4B as well as Figure 5 The stationary blade 21 shown includes a first impact plate 341 disposed on the leading edge 23a side and a second impact plate 342 disposed on the trailing edge 23b side.

[0149] exist Figure 5 , Figure 6A ,as well as Figure 6B In the stationary blade 21 shown, the inner edge 346 of the impact plate 340 is formed in a ring shape such that it surrounds the opening 323 of the insert cover 320 around the entire circumference when viewed from the blade height direction h.

[0150] It should be noted that, in Figure 4B as well as Figure 5 In the example shown, the first impact plate 341 has a first inner edge 346A, which includes a portion of an inner edge 346 formed in an annular shape. Figure 4B as well as Figure 5In the example shown, the second impact plate 342 has a second inner edge 346B, which includes the remaining portion of the inner edge 346 formed in an annular shape.

[0151] exist Figure 4B as well as Figure 5 In the stationary blade 21 shown, the first impact plate 341 and the second impact plate 342 are preferably arranged at different positions in the blade height direction h such that a portion of the first inner edge 346A and a portion of the second inner edge 346B overlap in the blade height direction h.

[0152] Therefore, it is difficult to generate a gap between the first inner edge 346A and the second inner edge 346B, thus reducing the possibility that cooling air will leak through the gap between the first impact plate 341 and the second impact plate 342 without passing through the multiple impact holes 344.

[0153] It should be noted that, in Figure 4B as well as Figure 5 In the stationary blade 21 shown, the downstream end 341a of the first impact plate 341 on the axial direction Da sandwiches the first inner edge 346A in the middle and extends from one side of the circumferential Dc of a pair of peripheral wall portions 251 to the other side. Figure 4B as well as Figure 5 In the illustrated stationary blade 21, the upstream end 342a of the second impact plate 342, along the axial direction Da, sandwiches the second inner edge 346B and extends from one side of the circumferential direction Dc of the pair of peripheral wall portions 251 to the other side. Furthermore, the downstream end 341a of the first impact plate 341, along the axial direction Da, is located downstream of the upstream end 342a of the second impact plate 342 within the entire circumferential direction Dc region, excluding the first inner edge 346A.

[0154] This further reduces the possibility that cooling air may leak through the gap between the first impact plate 341 and the second impact plate 342 without passing through the multiple impact holes 344.

[0155] exist Figure 4B as well as Figure 5 In the stationary blade 21 shown, the inner end face 321b of the insert cover 320 on the radial Dr side preferably includes a first end face 324 for fixing the first inner edge 346A and a second end face 325 for fixing the second inner edge 346B. The first end face 324 and the second end face 325 are preferably located at different positions in the blade height direction h.

[0156] Therefore, even if the blade height direction h is different in the first inner edge 346A and the second inner edge 346B, the gaps between the first inner edge 346A and the first end face 324, and between the second inner edge 346B and the second end face 325, can be minimized. Consequently, the possibility of cooling air leaking through these gaps can be reduced.

[0157] In the stationary blades 21 configured in this way, cooling air flows as follows.

[0158] Figure 7 It is used for explanation Figure 4B as well as Figure 5 A diagram showing the flow of cooling air in the stationary blade 21.

[0159] Cooling air supplied to the stationary blade 21 from a position radially outside the outer shield 27 flows into the inner space 312 from the radially outside end of the insert 310 and flows radially inside the inner space 312 as indicated by arrow a.

[0160] A portion of the cooling air flowing into the inner space 312 is ejected from the multiple impact holes 311 of the insert 310 into the inner space 24 of the blade-shaped portion 23, as shown by arrow b, thereby performing impact cooling on the inner surface 23i of the blade-shaped portion 23. The cooling air that has cooled the inner surface 23i of the blade-shaped portion 23 flows out from the multiple film cooling holes 23f that penetrate the blade-shaped portion 23 along the thickness direction, as shown by arrow c, and performs film cooling on the outer surface 23s of the blade-shaped portion 23.

[0161] The remaining portion of the cooling air flowing into the inner space 312, as shown by arrows d and e, flows into the second space 332 through the opening 323 of the insert cover 320 and the inner side of the annular inner edge 346 of the impact plate 340.

[0162] Cooling air flowing into the second space 332 is ejected from multiple impact holes 344 of the impact plate 340 into the third space 333 as indicated by arrow f, thereby impact cooling the inner surface 25b of the inner shield body 250 on the radial side Dr.

[0163] Thus, in several embodiments of the stationary blade 21, when cooling air is supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr), the cooling air from the inner space 312 of the insert 310 can flow into the first space 331 from the opening 323 of the insert cover 320. Therefore, the cooling air supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr) can reach the inner shield 25.

[0164] It should be noted that, as Figure 6B As shown in the stationary blade 21, a portion of the sealing plate 350A may also protrude from one side (inner side of radial Dr) of the pair of peripheral wall portions 251 in the blade height direction h at a position opposite to the opening 323 of the insert cover 320.

[0165] Therefore, even when the protrusion distance of the pair of peripheral wall portions 251 protruding to one side (inner side of radial Dr) in the blade height direction h is relatively short, the distance between the opening 323 of the insert cover 320 and the closing plate 350A can be ensured. Thus, the pressure loss of the cooling air flowing between the impact plate 340 and the closing plate 350A after passing through the opening 323 of the insert cover 320 and the inner side of the annular inner edge 346 of the impact plate 340 can be reduced.

[0166] In several embodiments of the stationary blade 21, as described above, the impact plate 340 is disposed between a second space 332 on one side (inner side of radial Dr) of the blade height direction h within the first space 331 and a third space 333 on the other side (outer side of radial Dr) of the blade height direction h within the first space 331.

[0167] Therefore, when cooling air is supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr), the cooling air from the inner space 312 of the insert 310 can flow into the second space 332. Furthermore, the cooling air flowing into the second space 332 can flow into the third space 333 through the plurality of impact holes 344 of the impact plate 340. Thus, in the stationary blade 21 of several embodiments, cooling air supplied from the other side of the blade height direction h (outer side of radial Dr) to the inner space 312 of the insert 310 can be supplied to the third space 333.

[0168] In several embodiments of the stationary blade 21, the inner edge 346 of the impact plate 340 is fixed to the end of the insert cover 320 on one side of the blade height direction h (inner side of radial Dr), that is, the end face 321b of the flange portion 321 in the insert cover 320 on the inner side of radial Dr.

[0169] The inner end face 321b of the insert cover 320 in the radial direction Dr easily ensures a relatively large area when viewed from the blade height direction h. Therefore, according to the stationary blade 21 of several embodiments, the inner edge 346 of the impact plate 340 can be easily fixed to the inner end face 321b of the insert cover 320 in the radial direction Dr.

[0170] exist Figure 5 , Figure 6A ,as well as Figure 6B In the stationary blade 21 shown, the inner edge 346 of the impact plate 340 is formed in a ring shape such that it surrounds the opening 323 of the insert cover 320 around the entire circumference when viewed from the blade height direction h.

[0171] Thus, the opening 323 of the insert cover 320 is located within the opening formed by the inner edge 346 which is formed in an annular shape. Therefore, when the cooling air from the inner space 312 of the insert 310 flows into the first space 331 (second space 332) from the opening 323 of the insert cover 320, the impact plate 340 will not become an obstruction and can flow in smoothly.

[0172] (The distance L between the inner end face 321b of the radial Dr of the insert cover 320 and the closing plate 350)

[0173] In several embodiments of the stationary blade 21, the distance L between the inner end face 321b of the insert cover 320 in the radial direction Dr and the closing plate 350 is preferably more than 20% of the equivalent diameter of the area S of the opening 323 of the insert cover 320 when viewed from the blade height direction h.

[0174] The inventors' in-depth research has led them to determine that when cooling air from the inner space 312 of the insert 310 flows from the opening 323 of the insert cover 320 into the first space 331 (second space 332), the amount of cooling air required for cooling the inner shield 25 is obtained if the distance L is more than 20% of the equivalent diameter of the area S.

[0175] Therefore, by setting the distance L to 20% or more of the equivalent diameter of the area S, the inner shield 25 can be adequately cooled.

[0176] (Manufacturing method of stationary blade 21)

[0177] The manufacturing methods of the stationary blade 21 in several embodiments will be described below.

[0178] Figure 8 It is a schematic cross-sectional view of the stationary blade 21 before the installation of the insert cover 320, the impact plate 340, and the closing plate 350.

[0179] Figure 9 This is a schematic cross-sectional view of the stationary blade 21 before the installation of the impact plate 340 and the sealing plate 350.

[0180] Figure 10 This is a schematic cross-sectional view of the stationary blade 21 before the installation of the sealing plate 350.

[0181] The manufacturing method of the stationary blade 21 in several embodiments includes a first assembly step S11, a second assembly step S12, and a third assembly step S13.

[0182] The first assembly step S11 is the process of fixing the insert cover 320 to the blade-shaped part 23. In the first assembly step S11, the operator... Figure 8 The stationary blade 21 with the insert 310 installed as shown is... Figure 9 Install the insert cover 320 as shown. That is, the operator installs it as shown. Figure 8 The stationary blade 21 shown has the protrusion 322 of the insert cover 320 fitted into the insert 310, and the flange 321 of the insert cover 320 is fixed to the end face 23p on the inner side of the radial Dr of the blade-shaped part 23, for example by welding.

[0183] It should be noted that in the first assembly step S11, the operator can also install the insert cover 320 on the stationary blade 21 before installing the insert 310. That is, the operator can also fix the flange portion 321 of the insert cover 320 to the inner end face 23p of the radial Dr of the blade-shaped portion 23, for example, by welding. Then, the operator can also insert the insert 310 into the internal space 24 of the blade-shaped portion 23 from the outer side of the radial Dr of the blade-shaped portion 23, so that the protrusion 322 of the insert cover 320 is fitted into the inner end of the radial Dr of the insert 310.

[0184] The second assembly step S12 is the process of fixing the outer edge 345 of the impact plate 340 to the inner protective cover 25 and fixing the inner edge 346 of the impact plate 340 to the insert cover 320 after performing the first assembly step S11. In the second assembly step S12, the operator performs the following steps: Figure 9 The stationary blade 21 after the insert cover 320 is installed as shown. Figure 10 Install the impact plate 340 as shown. That is, the operator... Figure 9 The stationary blade 21 shown fixes the outer edge 345 of the impact plate 340 to a pair of peripheral wall portions 251 and the leading edge retainer 61 by welding, for example, and fixes the inner edge 346 of the impact plate 340 to the inner end face 321b of the flange portion 321 in the insert cover 320 by welding, for example, the inner side of the flange portion 321 in the radial direction Dr.

[0185] The third assembly process S13 is the process of setting up the enclosure plate 350 by defining the first space 331 after the second assembly process S12. In the third assembly process S13, the operator... Figure 10 The stationary blade 21 with the impact plate 340 installed as shown, for example Figure 5As shown, the circumferential end of the closing plate 350, Dc, is fixed to a pair of peripheral wall portions 251 by welding, for example; the upstream end of the axial Da is fixed to the leading edge retainer 61 by welding, for example; and the downstream end of the axial Da is fixed to the trailing edge retainer 63 by welding, for example.

[0186] According to the manufacturing method of the stationary blade 21 according to several embodiments, it is possible to manufacture a stationary blade 21 that can supply cooling air from the other side (outer side of radial Dr) of the blade height direction h to the inner space 312 of the insert 310 to the inner shield 25.

[0187] (Repair method for static blade 21)

[0188] The following describes the repair methods for the stationary blade 21 in several embodiments.

[0189] Figure 11 This is a schematic cross-sectional view of the previous stationary blade 21X before repair.

[0190] Figure 12 This is a schematic cross-sectional view of the stationary blade 21 during repair before the installation of the impact plate 340 and the sealing plate 350.

[0191] The repair method for the stationary blade 21 in several embodiments includes a first repair step S21, a second repair step S22, and a third repair step S23.

[0192] (First repair procedure S21)

[0193] The first repair step S21 is the process of setting a new insert cover 320 having an opening 323 communicating with the inner space 312 of the insert 310. In the first repair step S21, a new insert cover 320 having an opening 323 can be set by implementing any one of the three repair methods described below.

[0194] (First repair method)

[0195] In the first repair method of the first repair step S21, a new insert cover 320 is installed by forming an opening 323 in the previous insert cover 320X before repair, which is fixed to the blade-shaped portion 23 of the previous stationary blade 21X. Therefore, in the first repair method, the operator... Figure 11 The conventional stationary blade 21X is shown with the conventional impact plate 340X and insert base plate 315 removed.

[0196] It should be noted that, in the first repair method, when removing the insert base plate 315, the operator preferably removes the insert base plate 315 from the insert 310 after pulling the insert 310 out of the internal space 24 of the blade-shaped portion 23.

[0197] It should be noted that, in Figure 11 In the conventional stationary blade 21X shown, an opening 323 is not formed in the conventional insert cover 320X. In addition, in the conventional stationary blade 21X, near the end of the insert 310 on the radial inner side Dr, an insert base plate 315 that separates the inner space 312 of the insert 310 into one side of the radial Dr and the other side is fixed to the inner circumferential surface of the insert 310, for example by welding.

[0198] In addition, Figure 11 The conventional stationary blade 21X shown includes, for example, a first impact plate 341X disposed on the leading edge 23a side and a second impact plate 342X disposed on the trailing edge 23b side, but the inner edge 346 of the impact plate 340 in several embodiments of the stationary blade 21 is absent.

[0199] Therefore, in Figure 11 In the conventional stationary blade 21X shown, cooling air supplied to the stationary blade 21X from a position radially outside the outer shroud (not shown) flows into the inner space 312 from the radially outside end of the insert 310 and flows radially inside the inner space 312.

[0200] All the cooling air flowing into the inner space 312 is ejected from the multiple impact holes 311 of the insert 310 into the inner space 24 of the blade-shaped portion 23, thereby performing impact cooling on the inner surface 23i of the blade-shaped portion 23. The cooling air that has cooled the inner surface 23i of the blade-shaped portion 23 flows out from the multiple film cooling holes 23f that penetrate the blade-shaped portion 23 along the thickness direction to the outside of the blade-shaped portion 23, thereby performing film cooling on the outer surface 23s of the blade-shaped portion 23.

[0201] exist Figure 11 In the conventional stationary blade 21X shown, the sealing plate 350 in the stationary blade 21 of the above-described embodiments is absent. When cooling air is supplied to the stationary blade 21X from a position that is radially inner to the inner side of the inner shield 25, the supplied cooling air is ejected from the multiple impact holes 344 of the impact plate 340X to the radially outer side of the inner side of the inner shield body 250 by impact cooling.

[0202] In the first repair method of the first repair step S21, the operator, as described above, from Figure 11 After removing the conventional impact plate 340X and the insert base plate 315 from the conventional stationary blade 21X shown, an opening 323 is formed in the conventional insert cover 320X fixed to the blade-shaped part 23.

[0203] In addition, in the first repair method, the operator installs the insert 310, after removing the insert base plate 315, onto the blade-shaped part 23.

[0204] Figure 12 This is a schematic cross-sectional view showing the conventional stationary blade 21X after the opening 323 is formed.

[0205] Previous insert cover 320X such Figure 11 As shown, the flange 321 is separated from the conventional impact plate 340X in the radial direction Dr, so the thickness of the flange 321 (the dimension of the radial direction Dr) is smaller than that of the flange 321 in the insert cover 320 of the stator blade 21 in several embodiments. Therefore, when the conventional insert cover 320X is reused in the first repair method and the second repair method described later, as Figure 12 As shown, the plate member 326 for thickness adjustment is fixed to the flange portion 321 by welding or the like. It should be noted that the plate member 326 has an opening 323 formed in the same way as the conventional insert cover 320X.

[0206] In addition, in the first repair method and the second repair method, instead of fixing the plate member 326 to the flange portion 321 of the conventional insert cover 320X by welding or the like, the thickness (radial Dr dimension) of the flange portion 321 can be adjusted by overlaying welding on the flange portion 321 of the conventional insert cover 320X.

[0207] It should be noted that the adjustment of the thickness (radial Dr dimension) of the flange portion 321 made by the plate member 326 and the above-mentioned overlay welding can be carried out not only when repairing the conventional stationary blade 21X as described above, but also when manufacturing a new stationary blade 21 in the third repair method described later.

[0208] (Second repair method)

[0209] In the second repair method of the first repair step S21, after the existing insert cover 320X has an opening 323 formed, a new insert cover 320 is installed by fixing the insert cover 320X to the blade-shaped portion 23. Therefore, in the second repair method, the operator... Figure 11 The conventional stationary blade 21X shown here has the conventional impact plate 340X, conventional insert cover 320X, and insert base plate 315 removed.

[0210] It should be noted that in the second repair method, the conventional insert cover 320X is removed, so the operator can remove the insert base plate 315 from the insert 310 while the insert 310 is still inserted into the internal space 24 of the blade-shaped portion 23. Alternatively, in the second repair method, when removing the insert base plate 315, the operator can remove the insert base plate 315 from the insert 310 after pulling the insert 310 out of the internal space 24 of the blade-shaped portion 23, just as in the first repair method.

[0211] In the second repair method, the operator proceeds as described above from... Figure 11 The conventional stationary blade 21X has its conventional impact plate 340X, conventional insert cover 320X, and insert base plate 315 removed, and an opening 323 is formed in the removed conventional insert cover 320X.

[0212] Then, the operator fixes the plate component 326 for thickness adjustment to the flange portion 321 by welding or the same method as the first repair method, or performs welding on the flange portion 321 of the conventional insert cover 320X, thereby adjusting the thickness (radial Dr dimension) of the flange portion 321.

[0213] Afterwards, the operator fixes the repaired conventional insert cover 320X, which has had the opening 323 formed and the thickness of the flange portion 321 adjusted, onto the blade-shaped portion 23. At this time, similar to the first assembly step S11 in the manufacturing method of the stationary blade 21 described above, the operator can also perform either the installation of the insert 310 or the fixing of the repaired conventional insert cover 320X to the blade-shaped portion 23.

[0214] (Third repair method)

[0215] In the third repair method of the first repair step S21, a new insert cover 320 is provided by fixing an insert cover 320 with an opening 323, which is a component other than the previous insert cover 320X before repair, to the blade-shaped portion 23. Therefore, in the third repair method, the operator from Figure 11 The conventional stationary blade 21X is shown with the conventional impact plate 340X, conventional insert cover 320X, and insert base plate 315 removed.

[0216] It should be noted that in the third repair method, the conventional insert cover 320X is removed, so the operator can remove the insert base plate 315 from the insert 310 while the insert 310 is still inserted into the internal space 24 of the blade-shaped portion 23. Alternatively, in the third repair method, when removing the insert base plate 315, the operator can remove the insert base plate 315 from the insert 310 after pulling the insert 310 out of the internal space 24 of the blade-shaped portion 23, just as in the first repair method.

[0217] In the third repair method, the operator, as described above, from... Figure 11 After removing the conventional impact plate 340X, conventional insert cover 320X, and insert base plate 315 from the conventional stationary blade 21X shown, a new insert cover 320 with an opening 323, which is a component other than the conventional insert cover 320X before repair, is fixed to the blade-shaped portion 23. At this time, similar to the first assembly step S11 in the manufacturing method of the stationary blade 21 described above, the operator can also perform either the installation of the insert 310 or the fixing of the new insert cover 320 to the blade-shaped portion 23.

[0218] In the first repair process S21, the operator processes the conventional insert cover 320X as described in the first and second repair methods above, or installs a new insert cover 320 of several embodiments onto the conventional stationary blade 21X as described in the third repair method.

[0219] Therefore, the conventional stationary blade 21X, after being processed as described above with the conventional insert cover 320X, becomes... Figure 12 The state shown, when the new insert cover 320 of several embodiments is installed, becomes Figure 9 The state shown.

[0220] In the following second repair step S22 and third repair step S23, the case in which a new insert cover 320 of several embodiments is installed in the first repair step S21 as in the third repair method will be described.

[0221] (Second repair procedure S22)

[0222] The second repair step S22 is the step of fixing the outer edge 345 of the impact plate 340 to the inner protective cover 25 and fixing the inner edge 346 of the impact plate 340 to the insert cover 320 after performing the first repair step S21. In the second repair step S22, the operator performs the repair on the impact plate 340 as follows: Figure 9 The stationary blade 21 is installed as shown after installing the new insert cover 320. Figure 10 Install the impact plate 340 as shown. That is, the operator... Figure 9The stationary blade 21 shown fixes the outer edge 345 of the impact plate 340 to a pair of peripheral wall portions 251 and the leading edge retainer 61 by welding, for example, and fixes the inner edge 346 of the impact plate 340 to the inner end face 321b of the flange portion 321 in the insert cover 320 by welding, for example, the inner side of the flange portion 321 in the radial direction Dr.

[0223] (Third repair procedure S23)

[0224] The third repair step S23 is a step performed after the second repair step S22, in which a sealing plate 350 is installed such that the insert cover 320 is sandwiched in the blade height direction h, and the first space 331 is defined on the side opposite to the blade-shaped portion 23, extending in a direction orthogonal to the blade height direction h, and communicating with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320. In the third repair step S23, the operator repairs the insert cover 350 as follows: Figure 10 The stationary blade 21 with the impact plate 340 installed as shown, for example Figure 5 As shown, the circumferential end of the closing plate 350, Dc, is fixed to a pair of peripheral wall portions 251 by welding, for example; the upstream end of the axial Da is fixed to the leading edge retainer 61 by welding, for example; and the downstream end of the axial Da is fixed to the trailing edge retainer 63 by welding, for example.

[0225] According to the repair method of the stationary blade 21 according to several embodiments, by repairing the conventional stationary blade 21X, cooling air supplied from the other side of the blade height direction h (outer side of radial Dr) to the inner space 312 of the insert 310 can be supplied to the inner shield 25.

[0226] The present invention is not limited to the above-described embodiments, but also includes modifications to the above-described embodiments and methods obtained by appropriately combining these methods.

[0227] For example, in the embodiments described above, the stationary blade 21 is configured such that cooling air supplied from the other side of the blade height direction h (outer side of radial Dr) to the inner space 312 of the insert 310 can reach the inner shroud 25. However, the stationary blade 21 may also be configured such that cooling air supplied from one side of the blade height direction h (inner side of radial Dr) to the inner space 312 of the insert 310 can reach the outer shroud 27.

[0228] The contents described in the above embodiments are as follows, for example.

[0229] (1) The turbine stationary blade 21 of at least one embodiment of the present invention comprises: a hollow blade body (blade-shaped portion 23) extending along the blade height direction h; a shroud (inner shroud 25) disposed at an end 23h on one side (inner side of radial Dr) of the blade body (blade-shaped portion 23) in the blade height direction h, and extending along a direction orthogonal to the blade height direction h; an insert 310 disposed in the inner space 24 of the blade body (blade-shaped portion 23) separated from the inner surface 23i of the blade body (blade-shaped portion 23) by a gap (the inner space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310); and an insert cover 320 covering the gap between the inner surface 23i of the blade body (blade-shaped portion 23) and the insert 310 (the inner space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310). The inner space 24) between the inner surface 23i of 3 and the outer peripheral surface 310s of the insert 310 is sealed at the end of one side (inner side of radial Dr) of the insert 310 and has an opening 323 communicating with the inner space 312 of the insert 310; a sealing plate 350, which clamps the insert cover 320 in the blade height direction h and extends along a direction orthogonal to the blade height direction h on the side opposite to the blade body (blade shape 23) and defines a first space 331 communicating with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320; and an impact plate 340, which fixes the outer edge 345 to the cover (inner cover 25) and the inner edge 346 to the insert cover 320 in such a way that it extends along the cover (inner cover 25) in the first space 331.

[0230] According to the structure described in (1) above, when cooling air is supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr), the cooling air from the inner space 312 of the insert 310 can flow into the first space 331 from the opening 323 of the insert cover 320. Thus, the cooling air supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outer side of radial Dr) can reach the shield (inner shield 25).

[0231] Therefore, in the turbine stationary blade 21, cooling air from either the inner shroud 25 side or the outer shroud 27 side can be supplied to the other shroud side of the inner shroud 25 side or the outer shroud 27 side.

[0232] (2) In several embodiments, in the structure described in (1) above, it is preferable that the impact plate 340 has a plurality of impact holes 344 extending through the impact plate 340 along its thickness direction. Preferably, the impact plate 340 is disposed between a second space 332 on one side (inner side of radial Dr) of the first space 331 in the blade height direction h and a third space 333 on the other side (outer side of radial Dr) of the first space 331 in the blade height direction h. Preferably, the second space 332 communicates with the inner space 312 of the insert 310 via the opening 323 of the insert cover 320. Preferably, the third space 333 communicates with the second space 332 via the plurality of impact holes 344.

[0233] According to the structure described in (2) above, when cooling air is supplied to the inner space 312 of the insert 310 from the other side of the blade height direction h (outside the radial Dr), the cooling air from the inner space 312 of the insert 310 can flow into the second space 332. Furthermore, the cooling air flowing into the second space 332 can flow into the third space 333 through a plurality of impact holes 344. Thus, in the turbine stationary blade 21, cooling air from either the inner shroud 25 side or the outer shroud 27 side can be supplied to the third space 333 in the shroud of the other side of the inner shroud 25 side or the outer shroud 27 side.

[0234] (3) In several embodiments, in the structure of (1) or (2) above, it is preferable that the inner edge 346 of the impact plate 340 is fixed to the end (end face 321b) of the blade height direction h (inner side of radial Dr) in the insert cover 320.

[0235] The end face 321b of the blade height direction h side (inner side of radial Dr) of the insert cover 320 can easily ensure a relatively large area when viewed from the blade height direction h. Therefore, according to the structure described in (3) above, it is easy to fix the inner edge 346 of the impact plate 340 to the end face 321b of the blade height direction h side (inner side of radial Dr) of the insert cover 320.

[0236] (4) In several embodiments, in the structure of (3) above, it is preferable that the inner edge 346 of the impact plate 340 is formed in a ring shape so as to surround the opening 323 of the insert cover 320 around the entire circumference when viewed from the blade height direction h.

[0237] According to the structure described in (4) above, the opening 323 of the insert cover 320 is located in the opening formed by the inner edge 346 which is formed in an annular shape. Therefore, when the cooling air from the inner space 312 of the insert 310 flows into the first space 331 from the opening 323 of the insert cover 320, the impact plate 340 will not become an obstacle and can flow in smoothly.

[0238] (5) In several embodiments, in the structure of (4) above, preferably, the impact plate 340 includes: a first impact plate 341 having a first inner edge 346A, the first inner edge 346A including a portion of an inner edge 346 formed in an annular shape; and a second impact plate 342 having a second inner edge 346B, the second inner edge 346B including the remaining portion of the inner edge 346 formed in an annular shape.

[0239] According to the structure described in (5) above, even if it is difficult to install the impact plate 340 on the cover (inner cover 25) when the impact plate 340 is made of a single plate component, the impact plate 340 can be easily installed on the cover (inner cover 25).

[0240] (6) In several embodiments, in the structure of (5) above, it is preferable that the first impact plate 341 and the second impact plate 342 are arranged at different positions in the blade height direction h such that a portion of the first inner edge 346A and a portion of the second inner edge 346B overlap in the blade height direction h.

[0241] According to the structure of (6) above, it is difficult to generate a gap between the first inner edge 346A and the second inner edge 346B, so the possibility of cooling air leaking from the gap between the first impact plate 341 and the second impact plate 342 without passing through the multiple impact holes 344 can be reduced.

[0242] (7) In several embodiments, in any of the structures described in (1) to (6) above, it is preferable that the distance L between the end face (end face 321b) of the blade height direction h side (inner side of radial Dr) of the insert cover 320 and the closing plate 350 is more than 20% of the equivalent diameter of the area S of the opening 323 of the insert cover 320 when viewed from the blade height direction h.

[0243] The inventors' in-depth research has shown that when cooling air from the inner space 312 of the insert 310 flows into the first space 331 through the opening 323 of the insert cover 320, if the distance L between the end face 321b of the blade height direction h (inner side of radial Dr) of the insert cover 320 and the closing plate 350 is more than 20% of the equivalent diameter of the area S of the opening 323 of the insert cover 320 when viewed from the blade height direction h, then the amount of cooling air required for cooling the shield (inner shield 25) is obtained.

[0244] According to the structure described in (7), the shield (inner shield 25) can be adequately cooled.

[0245] (8) In several embodiments, in any of the structures described in (1) to (7) above, preferably, the shroud (inner shroud 25) comprises: a plate-shaped shroud body (inner shroud body 250) extending along the circumferential Dc and axial Da of the turbine rotor (rotor 14) of the turbine 13 when the turbine stationary blade 21 is mounted on the turbine 13; and a pair of peripheral wall portions 251, the ends 25c of which extend along the extending direction of the end 25c on one side of the circumferential Dc and the other side of the shroud body (inner shroud body 250) and protrude toward one side (inner side of radial Dr) in the blade height direction h. A portion of the sealing plate 350A may also protrude toward one side (inner side of radial Dr) in the blade height direction h opposite the opening 323 of the insert cover 320 than the pair of peripheral wall portions 251.

[0246] According to the structure described above (8), even if the protrusion distance of the pair of peripheral wall portions 251 protruding to one side (inner side of radial Dr) in the blade height direction h is relatively short, the distance between the opening 323 of the insert cover 320 and the closing plate 350A can be ensured, thereby reducing the pressure loss of cooling air.

[0247] (9) In several embodiments, in any of the structures described in (1) to (8) above, it is preferred that the shield (inner shield 25) is an inner shield 25 located radially inside the turbine rotor (rotor 14) of the turbine 13 relative to the blade body (blade shape 23) when the turbine stationary blade 21 is mounted on the turbine 13.

[0248] According to the structure described above (9), cooling air from the side opposite to the inner shield 25 in the blade height direction h can be supplied to the inner shield 25.

[0249] (10) The gas turbine 10 of at least one embodiment of the present invention includes: a compressor 11; and a turbine 13 having a plurality of turbine stationary blades 21 of any one of the structures described in (1) to (9) above.

[0250] According to the structure described above (10), in the gas turbine 10, cooling air from either the inner shroud 25 side or the outer shroud 27 side of the turbine stationary blade 21 can be supplied to the other shroud side of the inner shroud 25 side or the outer shroud 27 side.

[0251] (11) In a method for manufacturing a turbine stationary blade 21 according to at least one embodiment of the present invention, the turbine stationary blade 21 comprises: a hollow blade body (blade-shaped portion 23) extending along the blade height direction h; a shroud (inner shroud 25) disposed at an end 23h of the blade body (blade-shaped portion 23) on one side (inner side of radial Dr) of the blade height direction h, and extending along a direction orthogonal to the blade height direction h; an insert 310 disposed in the inner space 24 of the blade body (blade-shaped portion 23) with a gap (an internal space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310) separated from the inner surface 23i of the blade body (blade-shaped portion 23); and an insert cover 320 covering the space between the inner surface 23i of the blade body (blade-shaped portion 23) and the insert 310. The gap (the internal space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310) is sealed at one end of the insert 310 (inner side of the radial Dr) and has an opening 323 communicating with the inner space 312 of the insert 310; a sealing plate 350, which clamps the insert cover 320 in the blade height direction h and extends along a direction orthogonal to the blade height direction h on the side opposite to the blade body (blade-shaped portion 23) and defines a first space 331 communicating with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320; and an impact plate 340, which fixes the outer edge 345 to the cover (inner cover 25) and the inner edge 346 to the insert cover 320 in such a way that it extends along the cover (inner cover 25) in the first space 331. A method for manufacturing a turbine stator blade 21 according to at least one embodiment of the present invention includes: a first assembly step S11, in which an insert cover 320 is fixed to a blade body (blade-shaped portion 23); a second assembly step S12, in which, after performing the first assembly step S11, the outer edge 345 of an impact plate 340 is fixed to a protective cover (inner protective cover 25), and the inner edge 346 of an impact plate 340 is fixed to the insert cover 320; and a third assembly step S13, in which, after performing the second assembly step S12, a sealing plate 350 is provided in a manner that defines a first space 331.

[0252] According to the method described in (11) above, it is possible to manufacture a turbine stator blade 21 that can supply cooling air from either the inner shield 25 side or the outer shield 27 side to the other shield of the inner shield 25 side or the outer shield 27 side.

[0253] (12) In the repair method of turbine stationary blade 21 according to at least one embodiment of the present invention, turbine stationary blade 21 includes: a hollow blade body (blade-shaped portion 23) extending along the blade height direction h; a shield (inner shield 25) disposed at the end 23h of the blade body (blade-shaped portion 23) on one side (inner side of radial Dr) of the blade height direction h, and extending along a direction orthogonal to the blade height direction h; and an insert 310 spaced apart from the inner surface 23i of the blade body (blade-shaped portion 23) by a gap (blade-shaped portion). The inner surface 23i of the blade body (blade-shaped portion 23) and the inner space 24 between the inner surface 23i of the blade body (blade-shaped portion 23) and the outer peripheral surface 310s of the insert 310 are disposed in the inner space 24 of the blade body (blade-shaped portion 23); and the insert cover 320 is fixed to the blade body (blade-shaped portion 23) and seals the gap between the inner surface 23i of the blade body (blade-shaped portion 23) and the insert 310 (the inner space 24 between the inner surface 23i of the blade-shaped portion 23 and the outer peripheral surface 310s of the insert 310) at one end of the insert 310 (inner side of radial Dr). The method for repairing a turbine stator blade 21 according to at least one embodiment of the present invention includes: a first repair step S21, providing a new insert cover 320 having an opening 323 communicating with the inner space 312 of the insert 310; a second repair step S22, after performing the first repair step S21, fixing the outer edge 345 of the impact plate 340 to the cover (inner cover 25) and fixing the inner edge 346 of the impact plate 340 to the insert cover 320; and a third repair step S23, after performing the second repair step S22, providing a sealing plate 350 such that it sandwiches the insert cover 320 in the blade height direction h and extends along a direction orthogonal to the blade height direction h on the side opposite to the blade body (blade-shaped part 23) and defines a first space 331 communicating with the inner space 312 of the insert 310 through the opening 323 of the insert cover 320. In the first repair step S21, any of the following is performed: a new insert cover 320 is provided by forming an opening 323 in the insert cover (previous insert cover 320X) before repair, which is fixed to the blade body (blade-shaped part 23) (first repair method); a new insert cover 320 is provided by fixing the insert cover 320X to the blade body (blade-shaped part 23) after forming an opening 323 in the insert cover (previous insert cover 320X) before repair (second repair method); and a new insert cover 320 is provided by fixing the insert cover 320 with an opening 323, which is a component other than the insert cover (previous insert cover 320X) before repair, to the blade body (blade-shaped part 23) (third repair method).

[0254] According to the method described in (12), by repairing the conventional turbine stator blades 21X, cooling air from either the inner shield 25 side or the outer shield 27 side can be supplied to the other shield of the inner shield 25 side or the outer shield 27 side.

Claims

1. A turbine stator blade, wherein, The turbine stationary blades have: The hollow blade body extends along the height of the blade; A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction; An insert is disposed in the internal space of the blade body with a gap between it and the inner surface of the blade body; An insert cover that seals the gap between the inner surface of the blade body and the insert at one end of the insert, and has an opening communicating with the inner space of the insert; A closing plate, which extends along a direction orthogonal to the blade height direction on the side opposite to the blade body, clamping the insert cover in the blade height direction, and defines a first space communicating with the inner space of the insert through the opening of the insert cover; as well as An impact plate, which secures its outer edge to the shield and its inner edge to the insert cover in such a manner that it extends along the shield within the first space.

2. The turbine stationary blade according to claim 1, wherein, The impact plate has a plurality of impact holes that penetrate the impact plate along its thickness direction. The impact plate is disposed between a second space on one side of the blade height direction within the first space and a third space on the other side of the blade height direction within the first space. The second space communicates with the inner space of the insert via the opening of the insert cover. The third space is connected to the second space via the plurality of impact holes.

3. The turbine stationary blade according to claim 1 or 2, wherein, The inner edge of the impact plate is fixed to the end of the blade in the height direction of the insert cover.

4. The turbine stationary blade according to claim 3, wherein, The inner edge of the impact plate is formed in a ring shape such that it surrounds the opening of the insert cover over the entire circumference when viewed from the height direction of the blade.

5. The turbine stationary blade according to claim 4, wherein, The impact plate includes: A first impact plate having a first inner edge, the first inner edge including a portion of the inner edge formed in an annular shape; and The second impact plate has a second inner edge, the second inner edge including the remaining portion of the inner edge formed in an annular shape.

6. The turbine stationary blade according to claim 5, wherein, The first impact plate and the second impact plate are configured at different positions in the blade height direction such that a portion of the first inner edge and a portion of the second inner edge overlap in the blade height direction.

7. The turbine stationary blade according to claim 1 or 2, wherein, The distance between the end of the insert cover on one side in the blade height direction and the closure plate is more than 20% of the equivalent diameter of the area of ​​the opening of the insert cover when viewed from the blade height direction.

8. The turbine stationary blade according to claim 1 or 2, wherein, The protective cover has the following features: A plate-shaped shroud body extending circumferentially and axially along the turbine rotor when the turbine stationary blades are mounted on the turbine; and A pair of peripheral wall portions, the ends of which extend along the extension direction of one side and the other side in the circumferential direction of the shield body and protrude toward the one side in the blade height direction. A portion of the sealing plate, positioned opposite the opening of the insert cover in the blade height direction, protrudes towards one side of the blade height direction compared to the pair of peripheral wall portions.

9. The turbine stationary blade according to claim 1 or 2, wherein, The shield is an inner shield located radially inside the turbine rotor of the turbine relative to the blade body when the turbine stationary blade is installed on the turbine.

10. A gas turbine, wherein, The gas turbine includes: Compressor; and A turbine having a plurality of turbine stationary blades as described in claim 1 or 2.

11. A method for manufacturing a turbine stator blade, wherein, The turbine stationary blades have: The hollow blade body extends along the height of the blade; A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction; An insert is disposed in the internal space of the blade body with a gap between it and the inner surface of the blade body; An insert cover that seals the gap between the inner surface of the blade body and the insert at one end of the insert, and has an opening communicating with the inner space of the insert; A sealing plate, which, on the side opposite to the blade body in the blade height direction, clamps the insert cover and extends in a direction orthogonal to the blade height direction, and defines a first space communicating with the inner space of the insert through the opening of the insert cover; as well as An impact plate, which extends along the shield within the first space, secures its outer edge to the shield and its inner edge to the insert cover. The method for manufacturing the turbine stationary blade includes: The first assembly step involves fixing the insert cover to the blade body; In the second assembly step, after performing the first assembly step, the outer edge of the impact plate is fixed to the protective cover, and the inner edge of the impact plate is fixed to the insert cover; and The third assembly step involves setting up the enclosure plate in a manner that defines the first space after the second assembly step.

12. A method for repairing turbine stator blades, wherein, The turbine stationary blades have: The hollow blade body extends along the height of the blade; A protective cover is disposed at one end of the blade body on one side of the blade height direction and extends in a direction orthogonal to the blade height direction; An insert is disposed in the internal space of the blade body with a gap between it and the inner surface of the blade body; as well as An insert cover, which is fixed to the blade body, seals the gap between the inner surface of the blade body and the insert at one end of the insert. The repair method for the turbine stationary blades includes: The first repair step involves providing a new insert cover with an opening communicating with the inner space of the insert; The second repair step involves, after performing the first repair step, fixing the outer edge of the impact plate to the protective cover and fixing the inner edge of the impact plate to the new insert cover; and In the third repair step, after the second repair step, a sealing plate is installed such that a first space is defined on the side opposite to the blade body, which is sandwiched between the new insert cover in the blade height direction, extending in a direction orthogonal to the blade height direction, and communicating with the inner space of the insert through the opening of the new insert cover. In the first repair process, any of the following is performed: The new insert cover is provided by forming the opening in the insert cover before repair, while the insert cover is fixed to the blade body. The new insert cover is provided by fixing the insert cover to the blade body after the opening is formed in the insert cover before repair; and The new insert cover is provided by fixing an insert cover with the opening, which is a component other than the insert cover before repair, to the blade body.

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