Blade segment and gas turbine

Abstract

A blade segment according to at least one embodiment of the present invention has a bolted first segment and a bolted second segment. A region of a first blade profile on a first side of a first outer shroud of the first segment on a leading edge side is provided with at least one first cooling hole that opens to a space enclosed by the first outer shroud and a first inner shroud and through which cooling air can flow. A region of a second blade profile on a second side of a second outer shroud of the second segment on a leading edge side is provided with at least one second cooling hole that opens to a space enclosed by the second outer shroud and a second inner shroud and through which cooling air can flow.

Description

Technical Field

[0001] This invention relates to a blade segment and a gas turbine.

[0002] This application claims priority based on Japanese Patent No. 2023-202521, filed with the Japan Patent Office on November 30, 2023, the contents of which are incorporated herein by reference. Background Technology

[0003] For example, in a gas turbine, which is an example of rotating machinery, the stationary blade of the turbine is known to be a stationary blade segment formed by connecting two stationary blades (segments) that have one airfoil, one outer shroud and one inner shroud (for example, see Patent Document 1).

[0004] Previous technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2022-183695 Summary of the Invention

[0007] The technical problem to be solved by the invention

[0008] In this type of stationary blade segment, the outer shrouds of two adjacent stationary blades in the circumferential direction abut against each other on the circumferential side surface of the outer shroud. In the leading edge region of this circumferential side surface, the temperature of the combustion gas passing through the gas path surface of the outer shroud is higher than that in the trailing edge region. Therefore, cooling based on the cooling channels provided in the outer shroud is prone to become insufficient, which can easily lead to thinning of the wall thickness.

[0009] In view of the above, at least one embodiment of the present invention aims to reduce the wall thickness of the outer shroud of the blade segment including two adjacent stationary blades in the circumferential direction.

[0010] means for solving technical problems

[0011] (1) The blade segment according to at least one embodiment of the present invention comprises:

[0012] The first segment includes a first airfoil portion, a first outer protective cover disposed on the outer side of the first airfoil portion in the blade height direction, and a first inner protective cover disposed on the inner side of the first airfoil portion in the blade height direction; and

[0013] The second segment includes a second airfoil, a second outer protective cover disposed on the outer side of the second airfoil in the blade height direction, and a second inner protective cover disposed on the inner side of the second airfoil in the blade height direction.

[0014] The first outer protective cover is bolted to the second outer protective cover.

[0015] The first inner protective cover is bolted to the second inner protective cover.

[0016] The first outer protective cover has a first side portion formed with a first side surface opposite to the second outer protective cover.

[0017] The second outer protective cover has a second side portion having a second side portion formed opposite to the first outer protective cover.

[0018] The region on the leading edge side of the first blade portion in the first side portion is provided with at least one first cooling hole, which faces the space opening sandwiched by the first outer shield and the first inner shield and allows cooling air to flow.

[0019] The region on the leading edge side of the second leaf-shaped portion in the second side portion is provided with at least one second cooling hole that faces the space opening sandwiched by the second outer shield and the second inner shield and allows cooling air to flow.

[0020] (2) The gas turbine according to at least one embodiment of the present invention comprises:

[0021] Rotor; and

[0022] The stationary blade ring is formed by arranging multiple blade segments of the above (1) structure along the circumference of the rotor.

[0023] Invention Effects

[0024] According to at least one embodiment of the present invention, it is possible to reduce the wall thickness of the outer shroud of the blade segment including two adjacent stationary blades in the circumferential direction. Attached Figure Description

[0025] Figure 1 This is a schematic diagram showing the overall structure of a gas turbine.

[0026] Figure 2 This is a cross-sectional view showing the gas flow path of the turbine.

[0027] Figure 3 This is a diagram showing the turbine stationary blades involved in several embodiments viewed from the radial outer side.

[0028] Figure 4 yes Figure 3 IV-IV view.

[0029] Figure 5 This is a schematic diagram showing the first outer shield and the second outer shield viewed from the inside to the outside in the blade height direction, relating to the blade segment of the first embodiment.

[0030] Figure 6 This is a partial perspective view of the blade segment involved in the second embodiment.

[0031] Figure 7 This is a schematic diagram of the first side view of the back side first side end of the first outer shield when viewed circumferentially in the blade segment according to the third embodiment.

[0032] Figure 8 This is a schematic diagram of the first side view of the second ventral end of the second outer shield in the blade segment according to the third embodiment, viewed circumferentially.

[0033] Figure 9 yes Figure 7 A schematic sectional view of the IX-IX direction.

[0034] Figure 10 This diagram illustrates the supply of cooling air to the first and second cooling holes.

[0035] Figure 11 This diagram illustrates the supply of cooling air to the first and second cooling holes.

[0036] Figure 12 This diagram illustrates the supply of cooling air to the first and second cooling holes.

[0037] Figure 13 This diagram illustrates the supply of cooling air to the first and second cooling holes. Detailed Implementation

[0038] 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 constituent parts described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0039] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configuration not only indicate such configuration in a strict sense, but also indicate a state of relative displacement by angle or distance with tolerance or to the extent that the same function can be obtained.

[0040] For example, expressions such as "same," "equal," and "homogeneous" that indicate that things are in the same state not only indicate that they are the same in a strict sense, but also that there are differences in the degree to which they can achieve the same function.

[0041] For example, the descriptions of shapes such as quadrilaterals and cylinders not only refer to quadrilaterals and cylinders in a strict geometric sense, but also include shapes with concave and convex parts, chamfers, etc., within the range where the same effect can be obtained.

[0042] On the other hand, the expression "possessing," "having," "including," "containing," or "having" a constituent element is not an exclusive expression that excludes the existence of other constituent elements.

[0043] Figure 1 This is a schematic diagram showing the overall structure of a gas turbine. Figure 2 This is a cross-sectional view showing the gas flow path of the turbine.

[0044] In this embodiment, such as Figure 1 As shown, the gas turbine 10 is configured such that a compressor 11, a burner 12, and a turbine 13 are arranged coaxially on a rotor 14, and a generator 15 is connected to one end of the rotor 14. In the following description, 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. The radial direction Dr is also referred to as the blade height direction.

[0045] In compressor 11, air AI drawn in from the intake port is compressed by multiple stationary and moving blades, thereby generating high-temperature / high-pressure compressed air AC. Combustor 12 supplies a specified amount of fuel FL to the compressed air AC and combusts it, thereby generating high-temperature / high-pressure combustion gas FG. Turbine 13 drives rotor 14 to rotate by the high-temperature / high-pressure combustion gas FG generated by combustor 12 through multiple stationary and moving blades, and drives generator 15 connected to rotor 14.

[0046] And, as Figure 2 As shown, in the turbine 13, the turbine stationary blade (stationary blade) 21 is configured such that the hub side of the blade portion 23 is fixed to the inner shroud 25, and the front end side is fixed to the outer shroud 27. The turbine moving blade (moving blade) 41 is configured such that the base end of the blade portion 43 is fixed to the platform 45. Furthermore, the outer shroud 27 and the dividing ring 51 disposed on the front end side of the moving blade 41 are supported in the turbine housing 30 via a heat insulation ring 53, and the inner shroud 25 is supported by a 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 platform 45, and the dividing ring 51.

[0047] Figure 3 This is a diagram showing the turbine stationary blade 21 of several embodiments viewed from the radial outside of Dr.

[0048] Figure 4 yes Figure 3 IV-IV view.

[0049] In several embodiments, the turbine stationary blade 21 is configured as a single blade segment 100 formed by bolting together two segments 101, each having a blade-shaped portion 23 disposed opposite to an outer shroud 27 and an inner shroud 25. Furthermore, the turbine 13 of this embodiment includes a stationary blade ring 20 formed by arranging multiple blade segments 100 along the circumferential direction Dc of the rotor 14.

[0050] Details regarding the blade segment 100 in one embodiment will be described in detail later.

[0051] In addition, such as Figure 3 As shown, the blade section 23 is formed by an ventral blade surface 23c formed by a concave surface as a pressure surface and a dorsal blade surface 23d formed by a convex surface as a negative pressure surface. The ventral blade surface 23c and the dorsal blade surface 23d are connected by a leading edge 23a on the upstream side and a trailing edge 23b on the downstream side in the axial direction to form an integrated blade section 23.

[0052] In addition, the inner shield 25 and the outer shield 27 function as gas path surface forming components. The gas path surface forming components have gas path surfaces that delineate the combustion gas flow path 32 and are in contact with the combustion gas FG. When there is no need to specifically distinguish between the inner shield 25 and the outer shield 27, the inner shield 25 and the outer shield 27 are sometimes simply referred to as shield 2.

[0053] (Regarding blade segment 100)

[0054] As described above, the blade segment 100 involved in several embodiments includes two bolted segments 101. In the following description, for ease of explanation, the segment 101 with its dorsal blade surface 23d positioned opposite the ventral blade surface 23c of the opposite segment 101 is designated as the first segment 101A, and the segment 101 with its ventral blade surface 23c positioned opposite the dorsal blade surface 23d of the opposite segment 101 is designated as the second segment 101B. Figure 3 In the diagram, segment 101 on the right is segment 101A, and segment 101B on the left is segment 2.

[0055] The first segment 101A includes a first blade portion 23A, a first outer protective cover 27A disposed on the outer side of the first blade portion 23A in the blade height direction, and a first inner protective cover 25A disposed on the inner side of the first blade portion 23A in the blade height direction.

[0056] Similarly, the second segment 101B includes a second airfoil 23B, a second outer shield 27B disposed on the outer side of the second airfoil 23B in the blade height direction, and a second inner shield 25B disposed on the inner side of the second airfoil 23B in the blade height direction (see below). Figure 8 ).

[0057] In the first segment 101A of the blade segment 100 involved in several embodiments, the first outer shield 27A has an outer region 155 on the side opposite to the gas path surface, i.e., the first gas path surface 27a1, i.e., the radially outer side of the first outer shield 27A, which is capable of storing cooling air supplied from the outside. The outer region 155 of the first segment 101A is a region surrounded by the first side end 151A (ventral first side end 151Ap) on the ventral blade surface 23c side, the first side end 151A (dorsal first side end 151As) on the dorsal blade surface 23d side, the first leading edge end 153A on the axial leading edge 23a side and the first trailing edge end 154A on the trailing edge 23b side of the axial Da, and forms a space portion 157 that is recessed in the radially inward direction of Dr. The bottom surface 155a of the outer region 155 of the first outer outer shield 27A forms a radially outer surface on the side opposite to the first gas path surface 27a1 in the radial direction Dr.

[0058] In several embodiments of the gas turbine 10, cooling air CA is supplied from the outside to the space 157 of the first section 101A.

[0059] In the first segment 101A of the blade segment 100 involved in several embodiments, the first inner shield 25A has a first side end 158A on the back side of the blade surface 23d side that forms the circumferential end of the first inner shield 25A.

[0060] Similarly, in the second segment 101B of the blade segment 100 involved in several embodiments, the second outer shield 27B has an outer region 155 on the side opposite to the gas path surface, i.e., the radially outer side of the second outer shield 27B, which is the side opposite to the gas path surface, i.e., the second gas path surface 27a2. The outer region 155 of the second segment 101B is a region surrounded by the second side end 151B (ventral second side end 151Bp) on the ventral blade surface 23c side, the second side end 151B (rear second side end 151Bs) on the dorsal blade surface 23d side, the second leading edge end 153B on the axial leading edge 23a side, and the second trailing edge end 154B on the trailing edge 23b side of the axial Da, and forms a space portion 157 that is recessed in the radially inward direction of Dr. The bottom surface 155a of the outer region 155 forming the second outer outer shield 27B forms a radially outer surface on the side opposite to the gas path surface 27a in the radial direction Dr.

[0061] In several embodiments of the gas turbine 10, cooling air CA is supplied from the outside to the space 157 of the second section 101B.

[0062] In the second segment 101B of the blade segment 100 involved in several embodiments, the second inner shroud 25B (see below) Figure 8 The second side end 158B has a ventral leaf surface 23c side on the end of the circumferential Dc that forms the second inner shroud 25B.

[0063] (Regarding the bolt connection between section 101A and section 201B)

[0064] In the first segment 101A of the blade segment 100 involved in several embodiments, a bolt hole 161 is formed that passes through the first side end 151As of the back side of the first outer shield 27A and the first side end 158A of the back side blade surface 23d side of the first inner shield 25A along the circumferential direction Dc.

[0065] In the first segment 101A of the blade segment 100 involved in several embodiments, a plurality of bolt holes 161 are formed at intervals along the axial direction Da at the first side end 151As on the back side of the first outer shroud 27A. Figure 3 and Figure 4 In the example shown, there are two bolt holes 161, but it can be one or more than three.

[0066] exist Figure 4In the example shown, a bolt hole 161 is formed at the first side end 158A of the first inner cover 25A, but multiple bolt holes 161 may also be formed at intervals along the axial direction Da.

[0067] In the second segment 101B of the blade segment 100 according to one embodiment, a bolt hole 162 is formed that passes through the second ventral end 151Bp of the second outer shield 27B and the second ventral end 158B of the second inner shield 25B on the ventral blade surface 23c side along the circumferential direction Dc.

[0068] In one embodiment, in the second segment 101B of the blade segment 100, a plurality of bolt holes 162 are formed at intervals along the axial direction Da at the second side end 151Bp on the ventral side of the second outer shroud 27B. Figure 3 In the example shown, there are two bolt holes 162, but there could be one or more than three.

[0069] exist Figure 8 In the example shown, a bolt hole 161 is formed at the second end 158B on the ventral blade 23c side of the second inner shield 25B, but multiple bolt holes 161 may also be formed at intervals along the axial direction Da.

[0070] The bolt hole 161 of the first section 101A and the bolt hole 162 of the second section 101B are respectively provided with positions that allow the bolt 171 to be inserted into the bolt hole 161 and the bolt hole 162.

[0071] In several embodiments of the blade segment 100, the first segment 101A and the second segment 101B are bolted together by inserting bolts 171 through bolt holes 161 and 162 and installing nuts 172.

[0072] Furthermore, in the turbine 13 of the gas turbine 10 according to several embodiments, a plurality of blade segments 100 are arranged along the circumferential direction Dc. Adjacent blade segments 100 on the circumferential direction Dc are not bolted together. A sealing plate (not shown) is arranged between adjacent blade segments 100 on the circumferential direction Dc to prevent cooling air CA from leaking between adjacent blade segments 100 on the circumferential direction Dc.

[0073] (Regarding the cooling structure of the outer shield 27)

[0074] The cooling structure of the outer shield 27 will be described below.

[0075] A collision plate (not shown) with multiple through holes is disposed in the outer region 155 of segments 101A and 101B to cover the entire bottom surface 155a of the outer region. Additionally, the collision plate (not shown) covers... Figure 3 The area shown in the image is shaded.

[0076] The outer region 155 of the space 157 is divided by a collision plate (not shown) into a space 157 on the outer radial side (Dr) and a space 157 on the inner radial side (Dr). The space 157 on the outer radial side (Dr) and the space 157 on the inner radial side (Dr) are connected by a through hole in the collision plate (not shown).

[0077] Cooling air supplied to the space 157 is supplied to the space 157 radially inward via a through hole in the collision plate (not shown), and performs impact cooling (impact cooling) on ​​the bottom surface 155a of the outer region. By performing impact cooling on the bottom surface 155a of the outer region, overheating caused by combustion gas FG on the first gas path surface 27a1 and the second gas path surface 27a2 is suppressed. The cooling air after impact cooling of the bottom surface 155a of the outer region is supplied to the first circumferential channel 121, the second circumferential channel 122, the first ventral side channel 131p, the first dorsal side channel 131s, the second ventral side channel 132p, and the second dorsal side channel 132s, which will be described later.

[0078] In the first segment 101A of several embodiments, a first opening 111 is formed on the wall surface of the space portion 157 facing the radially inner side of the first leading edge end 153A toward the trailing edge 23b side.

[0079] In the first segment 101A of several embodiments, a first circumferential channel 121 extending along the circumferential direction Dc is formed at the first leading edge end 153A.

[0080] In the first segment 101A of several embodiments, a ventral first side passage 131p extending along the axial direction Da is formed at the ventral first side end 151Ap, and a dorsal first side passage 131s extending along the axial direction Da is formed at the dorsal first side end 151As.

[0081] In the first segment 101A of several embodiments, the first circumferential channel 121 is a channel that connects the first opening 111 with the ventral first side channel 131p and the first opening 111 with the dorsal first side channel 131s.

[0082] In the first segment 101A involved in several embodiments, the ventral first side channel 131p is a channel formed from the front edge 23a side to the rear edge 23b side in the ventral first side end 151Ap, the upstream end is connected to the first circumferential channel 121, and the downstream end opens to the rear edge end 27d of the first outer cover 27A.

[0083] In the first segment 101A involved in several embodiments, the back side first side channel 131s is a channel formed from the front edge 23a side to the rear edge 23b side in the back side first side end 151As, the upstream end is connected to the first circumferential channel 121, and the downstream end opens to the rear edge end 27d of the first outer cover 27A.

[0084] In the first segment 101A of several embodiments, cooling air that has been subjected to impact cooling of the bottom surface 155a of the outer region flows from the first opening 111 into the first circumferential channel 121 in the first leading edge end 153A and flows through the first circumferential channel 121 to cool the first leading edge end 153A.

[0085] After the cooling air flowing in the first circumferential channel 121 flows in the first ventral side channel 131p and the first dorsal side channel 131s to cool the first ventral side end 151Ap and the first dorsal side end 151As, it is discharged to the outside of the first outer outer shield 27A from the rear edge end 27d.

[0086] In the second segment 101B of several embodiments, a second opening 112 is formed on the wall surface of the space portion 157 facing the radially inner side of the second leading edge end 153B toward the trailing edge 23b.

[0087] In the second segment 101B of several embodiments, a second circumferential channel 122 extending along the circumferential direction Dc is formed at the second leading edge end 153B.

[0088] In the second segment 101B of several embodiments, a ventral second side passage 132p extending along the axial direction Da is formed at the ventral second side end 151Bp, and a dorsal second side passage 132s extending along the axial direction Da is formed at the dorsal second side end 151Bs.

[0089] In the second segment 101B involved in several embodiments, the second circumferential channel 122 is a channel that connects the second opening 112 with the dorsal second side channel 132s and the second opening 112 with the ventral second side channel 132p.

[0090] In the second segment 101B involved in several embodiments, the ventral second side channel 132p is a channel formed from the front edge 23a side to the rear edge 23b side in the ventral second side end 151Bp, the upstream end is connected to the second circumferential channel 122, and the downstream end opens to the rear edge end 27d of the second outer cover 27B.

[0091] In the second segment 101B involved in several embodiments, the second side channel 132s on the back side is a channel formed from the front edge 23a side to the rear edge 23b side in the second side end 151Bs on the back side. The upstream end is connected to the second circumferential channel 122, and the downstream end opens to the rear edge end 27d of the second outer cover 27B.

[0092] In the second segment 101B of several embodiments, cooling air that has been subjected to impact cooling of the bottom surface 155a of the outer region flows from the second opening 112 into the second circumferential channel 122 in the second leading edge end 153B and flows through the second circumferential channel 122 to cool the second leading edge end 153B.

[0093] After the cooling air flowing in the second circumferential channel 122 flows in the second ventral side channel 132p and the second dorsal side channel 132s to cool the second ventral side end 151Bp and the second dorsal side end 151Bs, it is discharged from the rear edge end 27d of the second outer outer shield 27B to the outside of the second outer outer shield 27B.

[0094] (Regarding the first embodiment: the first cooling hole 181 and the second cooling hole 182)

[0095] Figure 5 This is a schematic diagram showing the first outer shield 27A and the second outer shield 27B viewed from the inside to the outside in the blade height direction of the blade segment 100 according to the first embodiment.

[0096] In the blade segment 100 involved in several embodiments, including the first embodiment and other embodiments described below, a first side surface 191 opposite to the second outer outer shield 27B is formed on the back side first side end 151As of the first outer outer shield 27A.

[0097] In several embodiments of the blade segment 100, a second side surface 192 opposite to the first outer shield 27A is formed on the ventral second side end 151Bp of the second outer shield 27B.

[0098] In several embodiments of the blade segment 100, a third side surface 193 is formed on the ventral first side end 151Ap of the first outer shroud 27A, on the side opposite to the first side surface 191, separated from the first leaf-shaped portion 23A.

[0099] In several embodiments of the blade segment 100, a fourth side surface 194 is formed on the back side of the second side end 151Bs of the second outer shroud 27B, on the side opposite to the second side surface 192, separated from the second blade portion 23B.

[0100] In the blade segment 100 according to the first embodiment, at least one first cooling hole 181 is provided in the region R1 on the leading edge 23a side of the first blade portion 23A in the first side end 151As on the back side, facing the space opening held by the first outer shield 27A and the first inner shield 25A, and through which cooling air can flow. Figure 5 In the example shown, multiple first cooling holes 181 are provided.

[0101] In the blade segment 100 according to the first embodiment, at least one second cooling hole 182 is provided in the region R2 on the leading edge 23a side of the second blade portion 23B in the second side end 151Bp on the ventral side, facing the space opening held by the second outer shield 27B and the second inner shield 25B, allowing cooling air to flow through. Figure 5 In the example shown, multiple second cooling holes 182 are provided.

[0102] In the blade segment 100 according to the first embodiment, at least one third cooling hole 183 is provided in the region R3 on the leading edge 23a side of the first blade portion 23A in the first ventral end portion 151Ap, facing the space opening held by the first outer shield 27A and the first inner shield 25A, allowing cooling air to flow through. Figure 5 In the example shown, multiple third cooling holes 183 are provided.

[0103] In the blade segment 100 according to the first embodiment, at least one fourth cooling hole 184 is provided in the region R4 on the leading edge 23a side of the second blade portion 23B in the second side end 151Bs on the back side, facing the space opening held by the second outer shield 27B and the second inner shield 25B, allowing cooling air to flow through. Figure 5 In the example shown, multiple fourth cooling holes 184 are provided.

[0104] As described later, cooling air can be supplied to the first cooling hole 181 from the first supply channel 241, which opens into the space portion 157 further radially inside the collision plate (not shown). Furthermore, as described later, cooling air can be supplied to the first cooling hole 181 from the first circumferential channel 121.

[0105] As described later, cooling air can be supplied to the third cooling hole 183 from the third supply channel 243, which opens into the space portion 157 further radially inside the collision plate (not shown). Furthermore, as described later, cooling air can be supplied to the third cooling hole 183 from the first circumferential channel 121.

[0106] Therefore, cooling air from the space portion 157, which is radially inner to the collision plate (not shown), can flow through the first cooling hole 181 or the third cooling hole 183 and be discharged from the opening facing the space sandwiched between the first outer shield 27A and the first inner shield 25A.

[0107] As described later, cooling air can be supplied to the second cooling hole 182 from the second supply channel 242, which opens into the space portion 157 further radially inside the collision plate (not shown). Furthermore, as described later, cooling air can be supplied to the second cooling hole 182 from the second circumferential channel 122.

[0108] As described later, cooling air can be supplied to the fourth cooling hole 184 from the fourth supply channel 244, which opens into the space portion 157 further radially inside the collision plate (not shown). Furthermore, as described later, cooling air can be supplied to the fourth cooling hole 184 from the second circumferential channel 122.

[0109] Therefore, cooling air from the space portion 157, which is radially inner to the collision plate (not shown), can flow through the second cooling hole 182 or the fourth cooling hole 184 and be discharged from the opening facing the space sandwiched between the first outer shield 27A and the first inner shield 25A.

[0110] In the blade segment 100 formed by bolting together the first segment 101A and the second segment 101B, the temperature in the regions R1 and R2 on the leading edge 23a side of the dorsal first side end 151As and the ventral second side end 151Bp is more likely to be higher than that on the trailing edge 23b side. Therefore, the wall thickness is more likely to be thinned in the regions on the leading edge 23a side of the first side 191 and the second side 192.

[0111] According to the blade segment 100 of the first embodiment, by providing a first cooling hole 181 and a second cooling hole 182 in regions R1 and R2 on the leading edge 23a side of the first back-side end 151As and the second ventral side end 151Bp, regions R1 and R2 on the leading edge 23a side of the first back-side end 151As and the second ventral side end 151Bp can be effectively cooled. This reduces the wall thickness reduction in the regions on the leading edge 23a side of the first side surface 191 and the second side surface 192.

[0112] In the gas turbine 10 of this embodiment, the turbine 13 includes a stationary blade ring 20 formed by arranging multiple blade segments 100 of several embodiments along the circumferential direction Dc of the rotor 14.

[0113] This reduces the wall thickness reduction in the region on the leading edge 23a side of the first side 191 and the second side 192 of the blade segment 100, thereby reducing the replacement frequency of the blade segment 100 and thus reducing the maintenance cost of the gas turbine 10.

[0114] (Regarding the second embodiment: the first chamfered portion 221 and the second chamfered portion 222)

[0115] Figure 6 This is a perspective view of the area near the aforementioned regions R1 and R2 of the blade segment 100 involved in the second embodiment.

[0116] In the blade segment 100 according to the second embodiment, the first outer shield 27A has a first leading edge side 211 facing the leading edge 23a side of the first blade portion 23A and the first gas path surface 27a1 facing the space sandwiched between the first outer shield 27A and the first inner shield 25A, and a corner 201 (see reference) where the first side 191, the first side 191, the first outer shield 27A, the first outer shield 27A, the first inner shield 25A, the first outer shield 27 ... Figure 5 The first chamfered part 221 is formed by chamfering.

[0117] In the blade segment 100 according to the second embodiment, the second outer shield 27B has a second leading edge side 212 facing the leading edge 23a side of the second blade portion 23B and the second side surface 192 of the second outer shield 27B, and a corner 202 that intersects the second gas path surface 27a2 facing the space sandwiched between the second outer shield 27B and the second inner shield 25B (see reference). Figure 5 The second chamfered part 222 is formed by chamfering.

[0118] In the blade segment 100 according to the second embodiment, the first chamfered portion 221 and the second chamfered portion 222 are provided with thermal barrier coatings, similar to the first gas path surface 27a1 or the second gas path surface 27a2.

[0119] The aforementioned corner 201 of the first outer shield 27A and the aforementioned corner 202 of the second outer shield 27B are areas that are difficult to cool and are relatively prone to thinning.

[0120] According to the blade segment 100 of the second embodiment, since the corners 201 and 202, which are relatively prone to wall thinning, are chamfered, wall thinning can be effectively suppressed.

[0121] In the blade segment 100 according to the second embodiment, when viewed from the blade height direction of the first blade section 23A, the intersection angle θ1 of the first side surface 191 and the leading edge side first side surface 211 (reference) Figure 5The angle is acute. At least one of the first cooling holes 181 may open at the first chamfer 221.

[0122] If the intersection angle θ1 of the first side 191 and the first side 211 of the leading edge is an acute angle, it is difficult to machine the opening of the cooling hole (first cooling hole 181) near the corner where the first side 191 and the first side 211 of the leading edge intersect, compared with the case where the intersection angle θ1 is an obtuse angle. Therefore, it is difficult to set the cooling hole (first cooling hole 181).

[0123] According to the blade segment 100 of the second embodiment, it is easy to machine the opening of the cooling hole (first cooling hole 181) in the chamfered portion such as the first chamfered portion 221, so it is easy to provide the first cooling hole 181. As a result, the first cooling hole 181 can be provided in the part that is difficult to cool and is relatively easy to become thinner, so it is possible to effectively suppress the thinning of the wall thickness.

[0124] (Regarding the third embodiment: the first coating region 231 and the second coating region 232)

[0125] Figure 7 This is a schematic diagram of the first side surface 191 of the back side first side end 151As of the first outer outer shield 27A when viewed from the circumferential direction Dc in the blade segment 100 according to the third embodiment.

[0126] Figure 8 This is a schematic diagram of the first side 191 of the ventral second side end 151Bp of the second outer shield 27B as viewed from the circumferential direction Dc in the blade segment 100 according to the third embodiment.

[0127] Figure 9 yes Figure 7 A schematic sectional view of the IX-IX direction.

[0128] In the blade segment 100 of the third embodiment, the first side surface 191 includes a first coating region 231 in which at least a portion of the region on the leading edge 23a side of the first blade portion 23A in the first side surface 191 is provided with an antioxidant coating.

[0129] In the blade segment 100 of the third embodiment, the second side surface 192 includes a second coating region 232 in which at least a portion of the region on the leading edge 23a side of the second blade portion 23B in the second side surface 192 is provided with an antioxidant coating.

[0130] The first coating region 231 and the second coating region 232 are opposite each other in the circumferential direction Dc, which is the direction in which the first outer shield and the second outer shield are arranged.

[0131] This reduces the wall thickness thinning in the first coating region 231 and the second coating region 232.

[0132] The anti-oxidation coating layer formed in the first coating region 231 and the second coating region 232 can be composed of CoNiCrAlY, NiCrAlY, CoCrAlY or MCrAlX (where M is Ni, Co or Ni and Co alloy, and X is Hf, Si or Ta).

[0133] In the blade segment 100 according to the third embodiment, the first side 191 need to have no height difference at the boundary between the first coating area 231 and the area that is not the first coating area 231.

[0134] That is, when the first coating region 231 is formed on the first side 191, the region corresponding to the first coating region 231 can be set to a shape that is more circumferentially inside the other regions Dc.

[0135] Similarly, the second side 192 need to have no height difference at the boundary between the second coating area 232 and the area that is not the second coating area 232.

[0136] That is, when the second coating region 232 is formed on the second side 192, the region corresponding to the second coating region 232 can be set to a shape that is more circumferentially inside the other regions Dc.

[0137] Therefore, when the first segment 101A and the second segment 101B are bolted together, the first coating region 231 and the second coating region 232 can be placed opposite each other without gap, so that the anti-oxidation coating formed on the first coating region 231 and the second coating region 232 will not be damaged.

[0138] In the blade segment 100 according to the third embodiment, the first coating region 231 is a region on the first side surface 191 from the end 191a on the leading edge 23a side of the first blade portion 23A to a position further toward the trailing edge 23b side of the first blade portion 23A than the end 191a by a predetermined distance a1, and is formed on the first side surface 191 from the end 191b on the inner side of the first blade portion 23A in the blade height direction to a position further toward the outer side of the first blade portion 23A in the blade height direction than the end 191b by a predetermined distance a2.

[0139] As described above, the region that forms the first coating region 231 is the region in the first side 191 where wall thickness thinning is relatively easy to occur.

[0140] According to the blade segment 100 of the third embodiment, a first coating region 231 is formed in the area of ​​the first side 191 where wall thickness thinning is relatively easy to occur, thereby effectively reducing the wall thickness thinning of the first side 191.

[0141] In the blade segment 100 according to the third embodiment, the second coating region 232 is a region on the second side surface 192 extending from the end 192a on the leading edge 23a side of the second blade portion 23B to a position further toward the trailing edge 23b side of the second blade portion 23B than the end 192a by a predetermined distance a3, and is formed on the second side surface 192 extending from the end 192b on the inner side of the blade height direction of the second blade portion 23B to a position further toward the outer side of the blade height direction of the second blade portion 23B than the end 192b by a predetermined distance a4.

[0142] As described above, the area that forms the second coating region 232 is the area in the second side 192 where wall thickness thinning is relatively easy to occur.

[0143] According to the blade segment 100 of the third embodiment, a second coating region 232 is formed in the area of ​​the second side 192 where wall thickness thinning is relatively easy to occur, thereby effectively reducing the wall thickness thinning of the second side 192.

[0144] (Regarding the fourth embodiment: Regarding the supply of cooling air to the first cooling hole 181 and the second cooling hole 182)

[0145] Figure 10 This diagram illustrates the supply of cooling air to the first cooling hole 181 and the second cooling hole 182 of the blade segment 100 according to the fourth embodiment. It is a schematic diagram of the outer shield 27 viewed from the outside to the inside in the blade height direction.

[0146] Figure 11 This diagram illustrates the supply of cooling air to the first cooling hole 181 and the second cooling hole 182 of the blade segment 100 according to the fourth embodiment. It is a schematic diagram of the outer shield 27 viewed from the inside to the outside in the blade height direction.

[0147] In addition, Figure 10 and Figure 11 The first outer shield 27A and the second outer shield 27B are described in the text, and the symbol for the second outer shield 27B is recorded in parentheses.

[0148] (First supply channel 241)

[0149] In the blade segment 100 according to the fourth embodiment, the first outer shield 27A has a first supply channel 241, which is configured to supply cooling air from the space portion 157, which is opposite to the space sandwiched between the first outer shield 27A and the first inner shield 25A, to the first cooling hole 181, and is different from the first circumferential channel 121 and the back side first side channel 131s.

[0150] In the blade segment 100 of the fourth embodiment, the first circumferential channel 121 and the back side first side channel 131s are connected by the first back side connecting channel 141s near the area where the first leading edge end 153A and the back side first side end 151As of the first outer outer shield 27A intersect.

[0151] The first supply channel 241 is formed, for example, to pass outside the blade height direction further than the first back-side connecting channel 141s, and is not connected to the first circumferential channel 121, the first back-side channel 131s, or the first back-side connecting channel 141s. Furthermore, when viewed from the blade height direction, the first supply channel 241 and the first back-side connecting channel 141s may or may not overlap.

[0152] The inlet opening 241a of the cooling air inlet side of the first supply channel 241 is an opening in the wall of the space portion 157 facing the rear edge 23b side in the first leading edge end 153A of the first outer cover 27A, i.e., facing the radially inner side of the space portion 157.

[0153] The opening on the cooling air outlet side of the first supply channel 241 is connected to the first dorsal chamber 251s near the area where the first leading edge end 153A of the first outer shroud 27A intersects with the first dorsal side end 151As.

[0154] In the blade segment 100 of the fourth embodiment, a plurality of first cooling holes 181 are connected to the first back side chamber 251s.

[0155] That is, in the first segment 101A according to the fourth embodiment, the cooling air after impact cooling of the bottom surface 155a of the outer region flows into the first supply channel 241 from the inlet opening 241a and is supplied to the first back chamber 251s. After the cooling air supplied to the first back chamber 251s flows into each of the first cooling holes 181 and flows in each of the first cooling holes 181 to cool the aforementioned region R1, it is discharged from the opening facing the space sandwiched by the first outer shield 27A and the first inner shield 25A.

[0156] According to the blade segment 100 of the fourth embodiment, by supplying cooling air from the first supply channel 241 to the first cooling hole 181, the flow rate of the cooling air supplied to the first cooling hole 181 can be easily ensured, thereby effectively cooling the region R1 on the leading edge 23a side of the back side first side end 151As. As a result, the wall thickness reduction of the region on the leading edge 23a side of the first side surface 191 can be effectively reduced.

[0157] (Second supply channel 242)

[0158] In the blade segment 100 according to the fourth embodiment, the second outer shield 27B has a second supply channel 242, which is configured to supply cooling air from the space portion 157, which is opposite to the space sandwiched between the second outer shield 27B and the second inner shield 25B, to the second cooling hole 182, and is different from the second circumferential channel 122 and the ventral second side channel 132p.

[0159] In the blade segment 100 of the fourth embodiment, the second circumferential channel 122 and the second ventral side channel 132p are connected by the second ventral connecting channel 142p near the area where the second leading edge end 153B and the second ventral side end 151Bp of the second outer shroud 27B intersect.

[0160] The second supply channel 242 is formed, for example, to extend further outward in the blade height direction than the second ventral connecting channel 142p, and is not connected to the second circumferential channel 122, the ventral second side channel 132p, or the second ventral connecting channel 142p. Furthermore, when viewed from the blade height direction, the second supply channel 242 and the second ventral connecting channel 142p may or may not overlap.

[0161] The inlet opening 242a of the cooling air inlet side of the second supply channel 242 is an opening in the wall of the space portion 157 facing the rear edge 23b side in the second leading edge end 153B of the second outer cover 27B.

[0162] The opening on the cooling air outlet side of the second supply channel 242 is connected to the second ventral chamber 252p near the area where the second leading edge end 153B of the second outer shield 27B intersects with the second ventral end 151Bp.

[0163] In the blade segment 100 of the fourth embodiment, a plurality of second cooling holes 182 are connected to the second ventral chamber 252p.

[0164] That is, in the second segment 101B according to the fourth embodiment, the cooling air after impact cooling of the bottom surface 155a of the outer region flows into the second supply channel 242 from the inlet opening 242a and is supplied to the second ventral chamber 252p. After the cooling air supplied to the second ventral chamber 252p flows into each of the second cooling holes 182 and flows in each of the second cooling holes 182 to cool the aforementioned region R2, it is discharged from the opening facing the space sandwiched by the second outer shield 27B and the second inner shield 25B.

[0165] According to the blade segment 100 of the fourth embodiment, by supplying cooling air from the second supply channel 242 to the second cooling hole 182, the flow rate of the cooling air supplied to the second cooling hole 182 can be easily ensured, thereby effectively cooling the region R2 on the leading edge 23a side of the second side end 151Bp on the ventral side. As a result, the wall thickness reduction of the region on the leading edge 23a side of the second side surface 192 can be effectively reduced.

[0166] (Third supply channel 243)

[0167] In the blade segment 100 of the fourth embodiment, the first outer shroud 27A has a third supply channel 243, which is configured to supply cooling air supplied from the space portion 157 to the third cooling hole 183, and is different from the first circumferential channel 121 and the ventral first side channel 131p.

[0168] In the blade segment 100 of the fourth embodiment, the first circumferential channel 121 and the ventral first side channel 131p are connected by the first ventral connecting channel 141p near the area where the first leading edge end 153A and the ventral first side end 151Ap of the first outer shroud 27A intersect.

[0169] The third supply channel 243 is formed, for example, to pass on the outer side of the blade height direction, which is further than the first ventral connecting channel 141p, and is not connected to the first circumferential channel 121, the ventral first lateral channel 131p, or the first ventral connecting channel 141p. Furthermore, when viewed from the blade height direction, the third supply channel 243 may or may not overlap with the first ventral connecting channel 141p.

[0170] The inlet opening 243a of the cooling air inlet side of the third supply channel 243 is an opening in the wall of the space portion 157 facing the rear edge 23b side in the first leading edge end 153A of the first outer cover 27A, i.e., facing the radially inner side of Dr.

[0171] The opening on the cooling air outlet side of the third supply channel 243 is connected to the first ventral chamber 251p near the area where the first leading edge end 153A of the first outer shroud 27A intersects with the first ventral end 151Ap.

[0172] In the blade segment 100 of the fourth embodiment, a plurality of third cooling holes 183 are connected to the first ventral chamber 251p.

[0173] That is, in the first segment 101A according to the fourth embodiment, the cooling air after impact cooling of the bottom surface 155a of the outer region flows into the third supply channel 243 from the inlet opening 243a and is supplied to the first ventral chamber 251p. After the cooling air supplied to the first ventral chamber 251p flows into each of the third cooling holes 183 and flows in each of the third cooling holes 183 to cool the aforementioned region R3, it is discharged from the opening facing the space sandwiched by the first outer shield 27A and the first inner shield 25A.

[0174] (4th supply channel 244)

[0175] In the blade segment 100 of the fourth embodiment, the second outer shield 27B has a fourth supply channel 244, which is configured to supply cooling air supplied from the space 157 to the fourth cooling hole 184, and is different from the second circumferential channel 122 and the second side channel 132s on the back side.

[0176] In the blade segment 100 of the fourth embodiment, the second circumferential channel 122 and the second back side channel 132s are connected by the second back side connecting channel 142s near the area where the second leading edge end 153B and the second back side end 151Bs of the second outer shroud 27B intersect.

[0177] The fourth supply channel 244 is formed, for example, to pass outside the blade height direction further than the second back-side connecting channel 142s, and is not connected to the second circumferential channel 122, the second back-side channel 132s, or the second back-side connecting channel 142s. Furthermore, when viewed from the blade height direction, the fourth supply channel 244 and the second back-side connecting channel 142s may or may not overlap.

[0178] The inlet opening 244a of the cooling air inlet side of the fourth supply channel 244 is an opening in the wall of the space portion 157 facing the rear edge 23b side in the second leading edge end 153B of the second outer cover 27B.

[0179] The opening on the cooling air outlet side of the fourth supply channel 244 is connected to the second dorsal chamber 252s near the area where the second leading edge end 153B of the second outer shroud 27B intersects with the second dorsal end 151Bs.

[0180] In the blade segment 100 of the fourth embodiment, a plurality of fourth cooling holes 184 are connected to the second back side chamber 252s.

[0181] That is, in the second segment 101B according to the fourth embodiment, the cooling air after impact cooling of the bottom surface 155a of the outer region flows into the fourth supply channel 244 from the inlet opening 244a and is supplied to the second back chamber 252s. The cooling air supplied to the second back chamber 252s flows into each of the fourth cooling holes 184 and flows in each of the fourth cooling holes 184 to cool the aforementioned region R4, and then is discharged from the opening facing the space sandwiched by the second outer shield 27B and the second inner shield 25B.

[0182] (Regarding the fifth embodiment: Regarding the supply of cooling air to the first cooling hole 181 and the second cooling hole 182)

[0183] Figure 12 This diagram illustrates the supply of cooling air to the first cooling hole 181 and the second cooling hole 182 of the blade segment 100 according to the fifth embodiment. It is a schematic diagram of the outer shield 27 viewed from the outside to the inside in the blade height direction.

[0184] Figure 13 This diagram illustrates the supply of cooling air to the first cooling hole 181 and the second cooling hole 182 of the blade segment 100 according to the fifth embodiment. It is a schematic diagram of the outer shield 27 viewed from the inside to the outside in the blade height direction.

[0185] In addition, Figure 12 and Figure 13 The first outer shield 27A and the second outer shield 27B are described in the text, and the symbol for the second outer shield 27B is recorded in parentheses.

[0186] In the blade segment 100 of the fifth embodiment, at least a portion of the plurality of first cooling holes 181 are connected to the first circumferential channel 121.

[0187] Therefore, cooling air can be supplied from the first ring to the first cooling hole 181 through the channel 121.

[0188] Furthermore, in the blade segment 100 according to the fifth embodiment, at least a portion of the plurality of first cooling holes 181 are connected to the back side first side channel 131s.

[0189] Therefore, cooling air from the first circumferential channel 121 can be supplied to the first cooling hole 181 via the first side channel 131s on the back side.

[0190] In addition, all of the plurality of first cooling holes 181 can be connected to the first circumferential channel 121, and all of the plurality of first cooling holes 181 can be connected to the back side first side channel 131s.

[0191] In the blade segment 100 of the fifth embodiment, at least a portion of the plurality of second cooling holes 182 are connected to the second circumferential channel 122.

[0192] Therefore, cooling air can be supplied from the second ring to the second cooling hole 182 through the channel 122.

[0193] Furthermore, at least a portion of the plurality of second cooling holes 182 are connected to the ventral second side channel 132p.

[0194] Therefore, cooling air from the second circumferential channel 122 can be supplied to the second cooling hole 182 via the second ventral side channel 132p.

[0195] In addition, all of the plurality of second cooling holes 182 can be connected to the second circumferential channel 122, and all of the plurality of second cooling holes 182 can be connected to the ventral second side channel 132p.

[0196] In the blade segment 100 of the fifth embodiment, at least a portion of the plurality of third cooling holes 183 are connected to the first circumferential channel 121.

[0197] Therefore, cooling air can be supplied from the first ring to the third cooling hole 183 through channel 121.

[0198] Furthermore, at least a portion of the plurality of third cooling holes 183 are connected to the ventral first side channel 131p.

[0199] Therefore, cooling air from the first circumferential channel 121 can be supplied to the third cooling hole 183 via the first lateral channel 131p on the ventral side.

[0200] In addition, all of the plurality of third cooling holes 183 can be connected to the first circumferential channel 121, and all of the plurality of third cooling holes 183 can be connected to the first ventral side channel 131p.

[0201] In the blade segment 100 of the fifth embodiment, at least a portion of the plurality of fourth cooling holes 184 are connected to the second circumferential channel 122.

[0202] Therefore, cooling air can be supplied from the second ring to the fourth cooling hole 184 in channel 122.

[0203] Furthermore, in the blade segment 100 according to the fifth embodiment, at least a portion of the plurality of fourth cooling holes 184 are connected to the back side second side channel 132s.

[0204] Therefore, cooling air from the second circumferential channel 122 can be supplied to the fourth cooling hole 184 via the second side channel 132s on the back side.

[0205] In addition, all of the plurality of fourth cooling holes 184 can be connected to the second circumferential channel 122, and all of the plurality of fourth cooling holes 184 can be connected to the second side channel 132s on the back side.

[0206] The present invention is not limited to the above embodiments, but also includes modifications or appropriate combinations thereof to the above embodiments.

[0207] For example, one or more of the above embodiments can be implemented in one blade segment 100, or different embodiments can be implemented for each blade segment 100.

[0208] Furthermore, for example, in embodiments 4 and 5 where the applicable parts are the same but different, different embodiments may be implemented depending on the applicable parts, such as the fourth embodiment for supplying cooling air to the first cooling hole 181 and the fourth cooling hole 184, and the fifth embodiment for supplying cooling air to the second cooling hole 182 and the third cooling hole 183.

[0209] The present invention is not limited to the above embodiments, but also includes modifications or appropriate combinations thereof to the above embodiments.

[0210] The contents described in the above embodiments can be understood as follows, for example.

[0211] (1) In at least one embodiment of the present invention, the blade segment 100 includes a first segment 101A, which includes a first blade portion 23A, a first outer protective cover 27A disposed on the outer side of the first blade portion 23A in the blade height direction, and a first inner protective cover 25A disposed on the inner side of the first blade portion 23A in the blade height direction. In at least one embodiment of the present invention, the blade segment 100 includes a second segment 101B, which includes a second blade portion 23B, a second outer protective cover 27B disposed on the outer side of the second blade portion 23B in the blade height direction, and a second inner protective cover 25B disposed on the inner side of the second blade portion 23B in the blade height direction. The first outer protective cover 27A and the second outer protective cover 27B are bolted together. The first inner shield 25A and the second inner shield 25B are bolted together. The first outer shield 27A has a first side portion (back side first side end 151As) with a first side surface 191 opposite to the second outer shield 27B. The second outer shield 27B has a second side portion (ventral side second side end 151Bp) with a second side surface 192 opposite to the first outer shield 27A. The region R1 on the leading edge 23a side of the first leaf-shaped portion 23A in the first side portion (back side first side end 151As) is provided with at least one first cooling hole 181 facing the space opening sandwiched by the first outer shield 27A and the first inner shield 25A, through which cooling air can flow. The region R2 on the leading edge 23a side of the second leaf-shaped portion 23B in the second side portion (the second side end 151Bp on the ventral side) is provided with at least one second cooling hole 182 facing the space opening held by the second outer shield 27B and the second inner shield 25B, and through which cooling air can flow.

[0212] In the blade segment 100 formed by bolting together the first segment 101A and the second segment 101B, the regions R1 and R2 on the leading edge 23a side of the first side (back side first side end 151As) and the second side (ventral side second side end 151Bp) are more prone to higher temperatures than the region on the trailing edge 23b side. Therefore, the region on the leading edge 23a side of the first side 191 and the second side 192 is prone to thinning of the wall thickness.

[0213] According to the structure described in (1) above, by providing a first cooling hole 181 and a second cooling hole 182 in regions R1 and R2 on the leading edge 23a side of the first side (back side first end 151As) and the second side (ventral side second end 151Bp), regions R1 and R2 on the leading edge 23a side of the first side (back side first end 151As) and the second side (ventral side second end 151Bp) can be effectively cooled. As a result, the wall thickness reduction of the regions on the leading edge 23a side of the first side 191 and the second side 192 can be reduced.

[0214] (2) In several embodiments, in the structure described in (1) above, the first side surface 191 may include a first coating region 231 on at least a portion of the region on the leading edge 23a side of the first blade portion 23A in the first side surface 191, which is covered with an antioxidant coating. The second side surface 192 may include a second coating region 232 on at least a portion of the region on the leading edge 23a side of the second blade portion 23B in the second side surface 192, which is covered with an antioxidant coating. The first coating region 231 and the second coating region 232 may be opposite each other in the direction (circumferential Dc) in which the first outer shield 27A and the second outer shield 27B are arranged.

[0215] According to the structure described in (2) above, the wall thickness reduction in the first coating region 231 and the second coating region 232 can be reduced.

[0216] (3) In several embodiments, in the structure described in (2) above, the first coating region 231 is the region in the first side surface 191 from the end 191a on the leading edge 23a side of the first blade portion 23A to the position on the trailing edge 23b side of the first blade portion 23A further away from the end 191a by a predetermined distance a1, and is formed in the region in the first side surface 191 from the end 191b on the inner side in the blade height direction of the first blade portion 23A to the position on the outer side in the blade height direction of the first blade portion 23A further away from the end 191b by a predetermined distance a2.

[0217] In the structure described above (3), the area where the first coating region 231 is formed is the area in the first side 191 where the wall thickness is relatively easy to be thinned.

[0218] According to the structure described in (3) above, a first coating region 231 is formed in the area of ​​the first side 191 where wall thickness thinning is relatively easy to occur, thereby effectively reducing wall thickness thinning in the first side 191.

[0219] (4) In several embodiments, in the structure of (2) or (3) above, the second coating region 232 is the region in the second side surface 192 from the end 192a on the leading edge 23a side of the second blade portion 23B to the position on the trailing edge 23b side of the second blade portion 23B further away from the end 192a by a predetermined distance a3, and is formed in the region in the second side surface 192 from the end 192b on the inner side in the blade height direction of the second blade portion 23B to the position on the outer side in the blade height direction of the second blade portion 23B further away from the end 192b by a predetermined distance a4.

[0220] In the structure described above (4), the area where the second coating region 232 is formed is the area in the second side 192 where the wall thickness is relatively easy to be thinned.

[0221] According to the structure of (4) above, a second coating region 232 is formed in the area of ​​the second side 192 where wall thickness thinning is relatively easy to occur, thus effectively reducing wall thickness thinning in the second side 192.

[0222] (5) In several embodiments, in any of the structures described in (1) to (4) above, the first outer shield 27A may have a first chamfered portion 221 formed by chamfering the first side surface 191, the first side surface 211 facing the leading edge 23a side of the first blade portion 23A, and the corner 201 facing the intersection of the first gas path surface 27a1 of the space sandwiched by the first outer shield 27A and the first inner shield 25A. The second outer shield 27B may have a second chamfered portion 222 formed by chamfering the second side surface 192, the second side surface 212 facing the leading edge 23a side of the second blade portion 23B, and the corner 202 facing the intersection of the second gas path surface 27a2 of the space sandwiched by the second outer shield 27B and the second inner shield 25B.

[0223] In the structure described above (5), the corner 201 of the first outer shield 27A and the corner 202 of the second outer shield 27B are parts that are difficult to cool and are relatively easy to become thinner.

[0224] According to the structure described in (5), since the corners 201 and 202, which are relatively prone to thinning, are chamfered, the thinning of the wall thickness can be effectively suppressed.

[0225] (6) In several embodiments, in the structure described in (5) above, the angle θ1 between the first side surface 191 and the leading edge side first side surface 211 when viewed from the blade height direction of the first blade portion 23A is an acute angle. At least one of the first cooling holes 181 is opened in the first chamfered portion 221.

[0226] If the intersection angle θ1 of the first side 191 and the first side 211 of the leading edge is an acute angle, it is difficult to machine the opening of the cooling hole (first cooling hole 181) near the corner where the first side 191 and the first side 211 of the leading edge intersect, compared with the case where the intersection angle θ1 is an obtuse angle. Therefore, it is difficult to set the cooling hole (first cooling hole 181).

[0227] According to the structure described in (6) above, it is easy to machine the opening of the cooling hole (first cooling hole 181) in the chamfered portion such as the first chamfered portion 221, so it is easy to provide the first cooling hole 181. As a result, the first cooling hole 181 can be provided in the part that is difficult to cool and is relatively easy to become thinner, so it is possible to effectively suppress the thinning of the wall thickness.

[0228] (7) In several embodiments, in any of the structures described in (1) to (6) above, the first outer shield 27A may have a leading edge side first air passage (first circumferential passage 121), which extends along the direction (circumferential Dc) in which the first outer shield 27A and the second outer shield 27B are arranged on the leading edge 23a side of the first blade portion 23A, and allows cooling air supplied from the outer first space (space portion 157) on the side opposite to the space sandwiched between the first outer shield 27A and the first inner shield 25A. The first outer shield 27A may have a first supply passage 241, which is configured to supply cooling air supplied from the outer first space (space portion 157) to the first cooling hole 181, and is different from the leading edge side first air passage (first circumferential passage 121).

[0229] According to the structure described in (7) above, by supplying cooling air from the first supply channel 241 to the first cooling hole 181, the flow rate of the cooling air supplied to the first cooling hole 181 can be easily ensured, thereby effectively cooling the region R1 on the leading edge 23a side of the first side portion (back side first side end 151As). As a result, the wall thickness reduction of the region on the leading edge 23a side of the first side surface 191 can be effectively reduced.

[0230] (8) In several embodiments, in any of the structures described in (1) to (7) above, the second outer shield 27B may have a leading edge side second air passage (second circumferential passage 122), which extends along the direction (circumferential Dc) in which the first outer shield 27A and the second outer shield 27B are arranged on the leading edge 23a side of the second leaf-shaped portion 23B, and allows cooling air supplied from the outer second space (space portion 157) on the side opposite to the space sandwiched between the second outer shield 27B and the second inner shield 25B. The second outer shield 27B may have a second supply passage 242, which is configured to supply cooling air supplied from the outer second space (space portion 157) to the second cooling hole 182, and is different from the leading edge side second air passage (second circumferential passage 122).

[0231] According to the structure described in (8) above, by supplying cooling air from the second supply channel 242 to the second cooling hole 182, the flow rate of the cooling air supplied to the second cooling hole 182 can be easily ensured, thereby effectively cooling the region R2 on the leading edge 23a side of the second side portion (ventral second side end 151Bp). As a result, the wall thickness reduction of the region on the leading edge 23a side of the second side portion 192 can be effectively reduced.

[0232] (9) In several embodiments, in any of the structures described in (1) to (6) above, the first outer shield 27A may have a leading edge side first air passage (first circumferential passage 121), which extends along the direction (circumferential Dc) in which the first outer shield 27A and the second outer shield 27B are arranged on the leading edge 23a side of the first blade portion 23A, and allows cooling air supplied from the outer first space (space portion 157) on the side opposite to the space sandwiched between the first outer shield 27A and the first inner shield 25A. The first cooling hole 181 may be connected to the leading edge side first air passage (first circumferential passage 121).

[0233] According to the structure described above (9), cooling air can be supplied to the first cooling hole 181 from the first air passage (first circumferential passage 121) on the leading edge side.

[0234] (10) In several embodiments, in any of the structures described in (1) to (6) or (9) above, the second outer shield 27B may have a leading-edge side second air passage (second circumferential passage 122), which extends along the direction (circumferential Dc) in which the first outer shield 27A and the second outer shield 27B are arranged on the leading edge 23a side of the second leaf-shaped portion 23B, and allows cooling air supplied from the outer second space (space portion 157) on the side opposite to the space sandwiched between the second outer shield 27B and the second inner shield 25B. The second cooling hole 182 may be connected to the leading-edge side second air passage (second circumferential passage 122).

[0235] According to the structure described above (10), cooling air can be supplied to the second cooling hole 182 from the second air passage (second circumferential passage 122) on the leading edge side.

[0236] (11) In several embodiments, in any of the structures described in (1) to (10) above, the first outer shield 27A may have a third side portion (ventral first side end 151Ap) having a third side 193 formed on the side opposite to the first side 191 across the first leaf-shaped portion 23A. The second outer shield 27B may have a fourth side portion (dorsal second side end 151Bs) having a fourth side 194 formed on the side opposite to the second side 192 across the second leaf-shaped portion 23B. The region R3 on the leading edge 23a side of the first leaf-shaped portion 23A in the third side portion (ventral first side end 151Ap) may have at least one third cooling hole 183 facing the space opening sandwiched between the first outer shield 27A and the first inner shield 25A, through which cooling air can flow. The region R4 on the leading edge 23a side of the second leaf-shaped portion 23B in the fourth side (second side end 151Bs on the back side) is provided with at least one fourth cooling hole 184 that faces the space opening held by the second outer shield 27B and the second inner shield 25B and allows cooling air to flow.

[0237] According to the structure described in (11) above, by providing a third cooling hole 183 and a fourth cooling hole 184 in regions R3 and R4 on the leading edge 23a side of the third side (ventral first side end 151Ap) and the fourth side (dorsal second side end 151Bs), the regions R3 and R4 on the leading edge 23a side of the third side (ventral first side end 151Ap) and the fourth side (dorsal second side end 151Bs) can be effectively cooled. As a result, the wall thickness reduction of the regions on the leading edge 23a side of the third side 193 and the fourth side 194 can be reduced.

[0238] (12) The gas turbine 10 according to at least one embodiment of the present invention includes: a rotor 14; and a stationary blade ring 20, which is formed by arranging a plurality of blade segments 100 of any of the structures in (1) to (11) along the circumferential direction Dc of the rotor 14.

[0239] According to the structure described above (12), the wall thickness of the region on the leading edge 23a side of the first side 191 and the second side 192 in the blade segment 100 can be reduced, thereby reducing the replacement frequency of the blade segment 100 and thus reducing the maintenance cost of the gas turbine 10.

[0240] Symbol Explanation

[0241] 2-Shield, 10-Gas turbine, 11-Compressor, 12-Burner, 13-Turbine, 14-Rotor, 15-Generator, 20-Stationary blade ring, 21-Turbine stationary blade (stationary blade), 23-Airfoil section, 23A-First airfoil section, 23B-Second airfoil section, 23a-Leading edge, 23b-Leading edge, 23c-Ventral blade surface, 23d-Dorsal blade surface, 25-Inner shield, 25A-First inner shield, 25B-Second inner shield, 27-Outer shield, 27A-First outer shield, 27a1-First gas path surface, 27a2-Second gas path surface, 27B-Second outer shield, 32-Combustion gas flow path, 100-Blade Segment, 101-Segment, 101A-Segment 1, 101B-Segment 2, 111-First opening, 112-Opening, 121-First circumferential channel, 122-Second circumferential channel, 131p-Ventral first lateral channel, 131s-Dorsal first lateral channel, 132p-Ventral second lateral channel, 132s-Dorsal second lateral channel, 141p-First ventral connecting channel, 141s-First dorsal connecting channel, 142p-Second ventral connecting channel, 142s-Second dorsal connecting channel, 151A-First lateral end, 151Ap-Ventral first lateral end, 151As-Dorsal first lateral end, 151B-Segment 1 2. End portions, 151Bp - ventral second end portion, 151Bs - dorsal second end portion, 153A - first leading edge end portion, 153B - second leading edge end portion, 154A - first trailing edge end portion, 154B - second trailing edge end portion, 155 - outer region, 155a - bottom surface of outer region, 157 - space portion, 158A - first end portion, 158B - second end portion, 181 - first cooling hole, 182 - second cooling hole, 183 - third cooling hole, 184 - fourth cooling hole, 191 - first side portion, 191a - end portion, 191b - end portion, 192 - second side portion, 192a - end portion, 192b - end portion, 193 - third... Side, 194-4th side, 201-corner, 202-corner, 211-first side of leading edge, 212-second side of leading edge, 221-first chamfer, 222-second chamfer, 231-first coating area, 232-second coating area, 241-first supply channel, 241a-inlet opening, 242-second supply channel, 242a-inlet opening, 234-3rd supply channel, 243a-inlet opening, 244-4th supply channel, 244a-inlet opening, 251p-1st ventral chamber, 251s-1st dorsal chamber, 252p-2nd ventral chamber, 252s-2nd dorsal chamber.

Claims

1. A leaf segment comprising: The first segment includes a first airfoil portion, a first outer protective cover disposed on the outer side of the first airfoil portion in the blade height direction, and a first inner protective cover disposed on the inner side of the first airfoil portion in the blade height direction; and The second segment includes a second airfoil, a second outer protective cover disposed on the outer side of the second airfoil in the blade height direction, and a second inner protective cover disposed on the inner side of the second airfoil in the blade height direction. The first outer protective cover is bolted to the second outer protective cover. The first inner protective cover is bolted to the second inner protective cover. The first outer protective cover has a first side portion formed with a first side surface opposite to the second outer protective cover. The second outer protective cover has a second side portion having a second side portion formed opposite to the first outer protective cover. The region on the leading edge side of the first blade portion in the first side portion is provided with at least one first cooling hole, which faces the space opening sandwiched by the first outer shield and the first inner shield and allows cooling air to flow. The region on the leading edge side of the second leaf-shaped portion in the second side portion is provided with at least one second cooling hole that faces the space opening sandwiched by the second outer shield and the second inner shield and allows cooling air to flow.

2. The blade segment according to claim 1, wherein, The first side surface includes a first coating region in which at least a portion of the region on the leading edge side of the first airfoil portion is provided with an antioxidant coating. The second side surface includes a second coating region in which at least a portion of the region on the leading edge side of the second airfoil portion is provided with an antioxidant coating. The first coating region and the second coating region are opposite each other in the direction in which the first outer shield and the second outer shield are arranged.

3. The blade segment according to claim 2, wherein, The first coating area is the region on the first side surface extending from the end of the leading edge of the first blade to the position further toward the trailing edge of the first blade than that end by a predetermined distance, and is formed on the first side surface extending from the end of the first blade in the blade height direction to the position further toward the outer side of the first blade in the blade height direction than that end by a predetermined distance.

4. The blade segment according to claim 2 or 3, wherein, The second coating region is the area on the second side surface extending from the end of the leading edge of the second blade to the position further toward the trailing edge of the second blade by a predetermined distance from that end, and is formed on the second side surface extending from the end of the second blade in the blade height direction to the position further toward the outer side of the second blade in the blade height direction by a predetermined distance from that end.

5. The blade segment according to any one of claims 1 to 3, wherein, The first outer shield has a first chamfered portion formed by chamfering the first side surface, the leading edge side of the first side surface of the first outer shield facing the leading edge side of the first blade portion, and the corner where the first gas path surface intersects the space sandwiched by the first outer shield and the first inner shield. The second outer shield has a second chamfered portion formed by chamfering the second side surface, the leading edge side of the second side surface of the second outer shield facing the leading edge side of the second blade portion, and the corner where the second gas path surface intersects the space sandwiched by the second outer shield and the second inner shield.

6. The blade segment according to claim 5, wherein, When viewed from the height direction of the first leaf-shaped portion, the angle between the first side surface and the first side surface on the leading edge is an acute angle. At least one of the first cooling holes opens at the first chamfer.

7. The blade segment according to any one of claims 1 to 3, wherein, The first outer protective cover has: A first air passage on the leading edge side extends along the direction in which the first outer shield and the second outer shield are arranged on the leading edge side of the first airfoil, and allows cooling air to flow from the outer first space on the side opposite to the space sandwiched between the first outer shield and the first inner shield; and The first supply channel, unlike the first air channel on the leading edge side, is configured to supply cooling air supplied from the outer first space to the first cooling hole.

8. The blade segment according to any one of claims 1 to 3, wherein, The second outer protective cover has: A second air passage on the leading edge side extends along the direction in which the first outer shield and the second outer shield are arranged on the leading edge side of the second airfoil, and allows cooling air to flow from the outer second space on the side opposite to the space sandwiched between the second outer shield and the second inner shield; and The second supply channel, unlike the second air channel on the leading edge side, is configured to supply cooling air supplied from the outer second space to the second cooling hole.

9. The blade segment according to any one of claims 1 to 3, wherein, The first outer shield has a first air passage on the leading edge side of the first blade portion, extending along the direction in which the first outer shield and the second outer shield are arranged, and through which cooling air supplied from an outer first space opposite to the space sandwiched between the first outer shield and the first inner shield can flow. The first cooling hole is connected to the first air channel on the leading edge side.

10. The blade segment according to any one of claims 1 to 3, wherein, The second outer shield has a leading-edge side second air passage extending along the direction in which the first outer shield and the second outer shield are arranged on the leading-edge side of the second blade portion, and through which cooling air supplied from an outer second space opposite to the space sandwiched between the second outer shield and the second inner shield can flow. The second cooling hole is connected to the second air channel on the leading edge side.

11. The blade segment according to any one of claims 1 to 3, wherein, The first outer protective cover has a third side portion formed on a third side portion that is opposite to the first side portion and separated from the first leaf-shaped portion. The second outer protective cover has a fourth side portion formed on a fourth side portion that is opposite to the second side portion and separated from the second leaf-shaped portion. The region on the leading edge side of the first blade portion in the third side portion is provided with at least one third cooling hole, which faces the space opening sandwiched by the first outer shield and the first inner shield and allows cooling air to flow. The region on the leading edge side of the second leaf-shaped portion in the fourth side is provided with at least one fourth cooling hole, which faces the space opening sandwiched by the second outer shield and the second inner shield and allows cooling air to flow.

12. A gas turbine comprising: Rotor; and The stationary blade ring is formed by arranging multiple blade segments as described in any one of claims 1 to 3 along the circumference of the rotor.

Images