Compressor stator blade, compressor provided with same, and gas turbine facility

Abstract

This compressor stator blade comprises a blade body having a blade shape in cross section, and a first shroud provided at an end on the first blade-height side of the blade body. A cavity is formed in the blade body and the first shroud, said cavity being continuous within the blade body and the first shroud, and opening at the first counter-gas path surface or the first-side circumferential surface. A plurality of suction holes are formed in the blade body, said suction holes having an inlet opening that opens at the negative pressure surface and an outlet opening that opens at an inner surface defining the cavity. In the negative pressure surface, an opening formation region is constituted of a region of predetermined width in the front-rear direction along which the front edge and the rear edge are aligned, said region extending from the end of the negative pressure surface on the first blade-height side to the end on the second blade-height side. In the opening formation region, an inlet opening is formed for each of the plurality of suction holes arranged in the blade height direction and the front-rear direction.

Description

Compressor stator vane, compressor equipped with same, and gas turbine equipment

[0001] This disclosure relates to a compressor stator vane, a compressor including the same, and a gas turbine facility including the compressor. This application claims priority to Japanese Patent Application No. 2024-030021, filed on February 29, 2024, the contents of which are incorporated herein by reference.

[0002] A gas turbine includes a compressor capable of compressing air to generate compressed air, a combustor capable of burning fuel in the compressed air to generate combustion gas, and a turbine capable of being driven by the combustion gas. The compressor includes a rotor rotating about an axis, a casing covering the rotor, and multiple stator blade rows. The rotor has a rotor shaft extending in an axial direction about the axis, and multiple rotor blade rows attached to the rotor shaft. The multiple rotor blade rows are arranged at intervals from each other in the axial direction. Each of the multiple rotor blade rows has a plurality of rotor blades arranged in a circumferential direction about the axis. Multiple stator blade rows are provided inside the casing. Each of the multiple stator blade rows is arranged axially downstream of one of the multiple rotor blade rows. Each of the multiple stator blade rows has a plurality of stator blades arranged in a circumferential direction about the axis.

[0003] The following Patent Documents 1 and 2 disclose compressor stator vanes.

[0004] The stator vane disclosed in Patent Document 1 has a hollow portion (cavity) formed therein that penetrates in the radial direction relative to the axis. A cooling medium such as cooling air is supplied to the rotor shaft from outside the casing through the hollow portion (cavity) of the stator vane and the casing. The technology disclosed in Patent Document 1 suppresses a decrease in creep strength of the stator vane and the rotor shaft by supplying cooling air to the stator vane and the rotor shaft.

[0005] The stator vane disclosed in Patent Document 2 has a gap formed through the stator vane, penetrating from the pressure surface to the suction surface. During compressor operation, air leaks from the pressure surface to the suction surface through the gap. The technology disclosed in Patent Document 2 suppresses boundary layer separation along the suction surface by causing air to leak from the pressure surface to the suction surface, thereby improving compression efficiency.

[0006] JP 11-315800 A JP 2013-100784 A

[0007] The present disclosure aims to provide a technology that can suppress the development of a boundary layer formed along the suction surface of a compressor stator vane, thereby expanding the operating range of the compressor and improving the efficiency of the compressor.

[0008] To achieve the above object, one aspect of the invention provides a compressor stator vane comprising: a blade body having an airfoil-shaped cross section and extending in a blade height direction including a directional component perpendicular to the cross section; a first shroud provided at an end of the blade body on the first blade height side among a first blade height side and a second blade height side in the blade height direction; and a second shroud provided at an end of the blade body on the second blade height side. The blade body has a leading edge, a trailing edge, a pressure side connecting the leading edge and the trailing edge, and a suction side connecting the leading edge and the trailing edge and in a back-to-back relationship with the pressure side. The first shroud has a first gas path surface facing the second blade height side and extending from the end of the blade body on the first blade height side in a direction including a directional component perpendicular to the blade height direction, a first counter-gas path surface facing the first blade height side and in a back-to-back relationship with the first gas path surface, and a first side peripheral surface connecting an edge of the first gas path surface to an edge of the first counter-gas path surface. The second shroud has a second gas path surface facing the first blade height side and extending from the end of the blade body on the second blade height side in a direction including a directional component perpendicular to the blade height direction, and a second counter-gas path surface facing the second blade height side and back-to-back with the second gas path surface. A cavity is formed in the blade body and the first shroud, connecting within the blade body and the first shroud and opening at the first counter-gas path surface or the first peripheral surface. The blade body is formed with a plurality of suction holes, each having an inlet opening at the suction surface and an outlet opening at an inner surface defining the cavity, penetrating from the suction surface to the inner surface defining the cavity. An opening formation region is formed in the suction surface, the region having a predetermined width in the fore-aft direction where the leading edge and the trailing edge are aligned, and extending from the end of the suction surface on the first blade height side to the end of the second blade height side. The opening formation region has an inlet opening for each of the plurality of suction holes aligned in the blade height direction and the fore-aft direction.

[0009] To achieve the above object, one aspect of the invention provides a compressor comprising: a compressor rotor rotatable about an axis; a compressor casing covering the compressor rotor; and a plurality of stator vane rows arranged in an axial direction along which the axis extends. The compressor rotor has a rotor shaft extending in the axial direction about the axis; and a plurality of moving blade rows arranged in the axial direction and attached to the rotor shaft. Each of the plurality of stator vane rows is disposed downstream in the axial direction of any one of the plurality of moving blade rows and attached to the compressor casing. Each of the plurality of stator vane rows has a plurality of stator vanes arranged in a circumferential direction about the axis. Each of the plurality of stator vane rows has a plurality of stator vanes arranged in a circumferential direction about the axis. The longitudinal direction is the axial direction. The blade height direction is a radial direction about the axis. The first blade height side is the radially outer side of the radially inner side and the radially outer side in the radial direction, and the second blade height side is the radially inner side.

[0010] A gas turbine facility according to one aspect of the invention for achieving the above object includes a gas turbine having the compressor, a combustor capable of generating combustion gas by burning fuel in air compressed by the compressor, and a turbine capable of being driven by the combustion gas, and a cooling device. The compressor casing is cylindrical about the axis and includes one or more blade rings that hold some of the multiple stator vane rows, and a casing body arranged outer circumferentially of the one or more blade rings and to which the one or more blade rings are attached. The blade ring that holds at least one stator vane row among the one or more blade rings has a blade ring bleed passage that penetrates from an inner circumferential side to an outer circumferential side and communicates with the cavities of each of the multiple stator vanes in the at least one stator vane row, and allows air from the cavities to flow in. The casing body has a body bleed passage that penetrates from an inner circumferential side to an outer circumferential side, and allows air to flow in from the blade ring bleed passage and be discharged to the outer circumferential side of the casing body. The turbine includes a turbine rotor rotatable about the axis, a turbine casing covering the turbine rotor, and a plurality of stator vane rows arranged in the axial direction and disposed on the inner periphery of the turbine casing. The cooling device includes a bleed air line connected to the main bleed air flow passage of the compressor casing, a cooler capable of cooling air from the bleed air line, a boost compressor capable of compressing the air cooled by the cooler, and a cooling air line capable of guiding the air cooled by the cooler and compressed by the boost compressor to at least one of the plurality of stator vane rows of the turbine.

[0011] According to one aspect of the present disclosure, it is possible to suppress the development of a boundary layer formed along the suction surface of a compressor stator vane, thereby expanding the operating range of the compressor and improving the efficiency of the compressor.

[0012] FIG. 1 is a schematic cross-sectional view of a gas turbine facility according to an embodiment of the present disclosure. FIG. 1 is a cross-sectional view of a main portion of a gas turbine according to an embodiment of the present disclosure. FIG. 2 is a side view of a stator vane according to a first embodiment of the present disclosure. FIG. 3 is a cross-sectional view taken along line IV-IV in FIG. 3. FIG. 3 is a cross-sectional view taken along line V-V in FIG. 3. FIG. 4 is a cross-sectional view of a main portion of a blade body according to a first embodiment of the present disclosure. FIG. 5 is a graph showing the relationship between the incidence angle and pressure loss when the axial central position of the opening formation region is changed. FIG. 6 is a graph showing the relationship between the incidence angle and pressure loss when the axial central position of the opening formation region and the opening density of the inner region are changed. FIG. 7 is a side view of a stator vane according to a second embodiment of the present disclosure. FIG. 8 is a graph showing the relationship between the incidence angle and pressure loss when the axial central position of the opening formation region and the opening density of the inner region are changed. FIG. 9 is a side view of a stator vane according to a third embodiment of the present disclosure. FIG. 10 is a side view of a stator vane according to a fourth embodiment of the present disclosure. FIG. 11 is a graph showing the relationship between the incidence angle and pressure loss when the shape of each region in the opening formation region and the opening density of each region are changed. FIG. 12 is a side view of a stator vane according to a fifth embodiment of the present disclosure. Fig. 15 is a cross-sectional view taken along line XV-XV in Fig. 14. Fig. 16 is a cross-sectional view taken along line XVI-XVI in Fig. 14. Fig. 17 is a graph showing the relationship between the incidence angle and pressure loss when the presence or absence of suction holes in the outer shroud and the inner shroud is changed.

[0013] Various embodiments and modifications of the present disclosure will be described in detail below with reference to the drawings.

[0014] [Embodiment of Gas Turbine Facility] An embodiment of a gas turbine facility will be described with reference to Figs. 1 and 2 .

[0015] 1 , the gas turbine facility includes a gas turbine 10 and a cooling device 16. The gas turbine 10 includes a compressor 40 capable of compressing air A to generate compressed air, a plurality of combustors 20 capable of burning fuel F in the compressed air to generate combustion gas G, and a turbine 30 capable of being driven by the combustion gas G.

[0016] The compressor 40 is a multi-stage axial flow compressor. The compressor 40 includes a compressor rotor 41 rotatable about an axis Ar, a compressor casing 45 that covers the compressor rotor 41, and multiple stator vane rows 48. The turbine 30 includes a turbine rotor 31 rotatable about the axis Ar, a turbine casing 35 that covers the turbine rotor 31, and multiple stator vane rows 38. Hereinafter, the direction in which the axis Ar extends is referred to as the axial direction Da, one side of the axial direction Da is referred to as the axial upstream side Dau, and the other side is referred to as the axial downstream side Dad. The radial direction relative to the axis Ar is simply referred to as the radial direction Dr, and the side of the radial direction Dr that approaches the axis Ar is referred to as the radial inner side Dri, and the side that moves away from the axis Ar is referred to as the radial outer side Dro. Furthermore, the circumferential direction centered on the axis Ar is simply referred to as the circumferential direction Dc.

[0017] The compressor 40 is disposed on the axial upstream side Dau with respect to the turbine 30. The compressor rotor 41 and the turbine rotor 31 are located on the same axis Ar and are connected to each other to form the gas turbine rotor 11. For example, a rotor of a generator GEN is connected to this gas turbine rotor 11. The gas turbine 10 further includes an intermediate casing 14 disposed between the compressor casing 45 and the turbine casing 35. Compressed air from the compressor 40 flows into this intermediate casing 14. The multiple combustors 20 are attached to the intermediate casing 14 and aligned in the circumferential direction Dc. The compressor casing 45, the intermediate casing 14, and the turbine casing 35 are connected to each other to form the gas turbine casing 15.

[0018] The compressor rotor 41 has a rotor shaft 42 that extends in the axial direction Da around the axis Ar, and a plurality of rotor blade rows 43 attached to the rotor shaft 42. The plurality of rotor blade rows 43 are aligned in the axial direction Da. Each rotor blade row 43 is composed of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 48 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 43. Each stator blade row 48 is provided inside the compressor casing 45. Each stator blade row 48 is composed of a plurality of stator blades aligned in the circumferential direction Dc.

[0019] The turbine rotor 31 has a rotor shaft 32 extending in the axial direction Da centered on the axis Ar, and a plurality of rotor blade rows 33 attached to the rotor shaft 32. The plurality of rotor blade rows 33 are aligned in the axial direction Da. Each rotor blade row 33 is composed of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 38 is arranged on the axial upstream side Dau of each of the plurality of rotor blade rows 33. Each stator blade row 38 is provided inside the turbine casing 35. Each stator blade row 38 is composed of a plurality of stator blades aligned in the circumferential direction Dc.

[0020] The cooling device 16 has an extraction line 17 a, a cooler 18, a cooling air line 17 b, and a boost compressor 19. One end of the extraction line 17 a is connected to the compressor casing 45. Air inside the compressor casing 45 can flow into this extraction line 17 a. The cooler 18 can cool the air from the extraction line 17 a. The cooling air line 17 b is connected to a discharge port of the boost compressor 19. This cooling air line 17 b can guide the air cooled by the cooler 18 and compressed by the boost compressor 19 to at least one of the multiple stator blade rows 38 of the turbine 30.

[0021] As shown in Fig. 2, the compressor casing 45 has a plurality of blade rings 47, 47a and a casing main body 46. The plurality of blade rings 47, 47a are cylindrical and centered on the axis Ar. The plurality of blade rings 47, 47a are aligned in the axial direction Da. Each of the plurality of blade rings 47, 47a holds one or more stator blade rows 48, 48a.

[0022] Each of the multiple stator vanes 50, 50a constituting the stator vane rows 48, 48a includes a blade body 51, a first shroud 61o, and a second shroud 61i. The blade body 51 has an airfoil-shaped cross section and extends in a blade height direction Dr, which includes a directional component perpendicular to the cross section. The blade body 51 includes a leading edge 51L, a trailing edge 51T, a pressure surface 52p connecting the leading edge 51L and the trailing edge 51T, and a suction surface 52n connecting the leading edge 51L and the trailing edge 51T and facing back-to-back with the pressure surface 52p. The first shroud 61o is provided at the end of the first blade height side Dro of the blade body 51 in the blade height direction Dr. The second shroud 61i is provided at the end of the second blade height side Dri of the blade body 51. The first shroud 61o has a first gas path surface 62o facing the blade height second side Dri and extending in a direction including a directional component perpendicular to the blade height direction Dr from an end of the blade height first side Dro of the blade body 51, a first counter-gas path surface 63o facing the blade height first side Dro and being back-to-back with the first gas path surface 62o, and a first side peripheral surface 64o connecting an edge of the first gas path surface 62o and an edge of the first counter-gas path surface 63o. The second shroud 61i has a second gas path surface 62i facing the blade height first side Dro and extending in a direction including a directional component perpendicular to the blade height direction Dr from an end of the blade height second side Dri of the blade body 51, and a second counter-gas path surface 63i facing the blade height second side Dri and being back-to-back with the second gas path surface 62i.

[0023] The blade rings 47, 47a have gas path surfaces 47p facing the radially inward direction Dri and defining the outer edge of the annular compressed air flow path through which air flows, and blade grooves 47g recessed from the gas path surfaces 47p toward the radially outward direction Dro. The first shrouds 61o of the stator vanes 50, 50a are fitted into the blade grooves 47g. Therefore, when the stator vanes 50, 50a are attached to the compressor casing 45, the blade height direction Dr is the radial direction Dro. Furthermore, the blade height first side Dro is the radially outward side Dro, and the blade height second side Dri is the radially inward side Dri. Furthermore, the fore-and-aft direction Da in which the leading edge 51L and trailing edge 51T of the blade body 51 are aligned is the axial direction Da. Furthermore, the side in the fore-aft direction Da where the leading edge 51L is located relative to the trailing edge 51T is the axial upstream side Dau, and the side in the fore-aft direction Da where the trailing edge 51T is located relative to the leading edge 51L is the axial downstream side Dad. Therefore, hereinafter, the blade height direction Dr is referred to as the radial direction Dr, the blade height first side Dro is referred to as the radially outer side Dro, the blade height second side Dri is referred to as the radially inner side Dri, the fore-aft direction Da is referred to as the axial direction Da, the side of the leading edge 51L in the fore-aft direction Da is referred to as the axial upstream side Dau, and the side of the trailing edge 51T in the fore-aft direction Da is referred to as the axial downstream side Dad. Furthermore, the side in the circumferential direction Dc where the pressure surface 52p is located relative to the suction surface 52n is referred to as the circumferential pressure side Dcp, and the side in the circumferential direction Dc where the suction surface 52n is located relative to the pressure surface 52p is referred to as the circumferential suction side Dcn. Furthermore, the first shroud 61o is referred to as the outer shroud 61o, the first gas path surface 62o of the first shroud 61o is referred to as the outer gas path surface 62o, and the first counter-gas path surface 63o of the first shroud 61o is referred to as the outer counter-gas path surface 63o. Furthermore, the second shroud 61i is referred to as the inner shroud 61i, the second gas path surface 62i of the second shroud 61i is referred to as the inner gas path surface 62i, and the second counter-gas path surface 63i of the second shroud 61i is referred to as the inner counter-gas path surface 63i.

[0024] First Embodiment of Compressor Stator Vanes Hereinafter, a first embodiment of a compressor stator vane will be described.

[0025] As shown in FIG. 2, the compressor stator vane 50a in this embodiment is a stator vane that constitutes one of the stator vane rows 48a among the plurality of stator vane rows 48, 48a.

[0026] As shown in Figures 3 to 5, the stator vane 50a has a cavity 70 that is continuous within the inner shroud 61i, the blade body 51, and the outer shroud 61o. A side peripheral surface (first side peripheral surface) 64o of the outer shroud 61o has a leading end surface 64f facing the axial upstream side Dau, a trailing end surface 64b facing the axial downstream side Dad and in a back-to-back relationship with the leading end surface 64f, and a pair of side end surfaces 64s facing the circumferential direction Dc. The cavity 70 includes an inner cavity 73 within the inner shroud 61i, a blade-body cavity 72 within the blade body 51, and an outer cavity 71 within the outer shroud 61o. The inner cavity 73 is connected to the blade-body cavity 72. The blade-body cavity 72 is connected to the outer cavity 71. The outer cavity 71 opens at the leading end surface 64f of the outer shroud 61o.

[0027] As shown in Figures 3 and 4, the blade body 51 is formed with a plurality of suction holes 55. Each suction hole 55 has an inlet opening 55i that opens on the suction surface 52n of the blade body 51 and an outlet opening 55o that opens on a suction-side inner surface 72p, which is a surface of the inner surface of the blade-body cavity 72 that is back-to-back with the suction surface 52n. Thus, each suction hole 55 penetrates from the suction surface 52n to the suction-side inner surface 72p. A portion of the air flowing along the suction surface 52n of the blade body 51 flows into the cavity 70 through the plurality of suction holes 55. As shown in Figure 2, the blade ring 47a that holds the stator vane row 48a has a blade ring bleed passage 47e that penetrates from the inner periphery to the outer periphery and communicates with the cavity 70 for each of the plurality of stator vanes 50a in the stator vane row 48a. The blade ring bleed air passage 47e is connected to the openings of the cavities 70 of each of the multiple stator vanes 50a in the stator vane row 48a, allowing air to flow in from the cavities 70. The casing main body 46, which is arranged on the outer circumferential side of the multiple blade rings 47, 47a, has a main bleed air passage 46e that penetrates from the inner circumferential side to the outer circumferential side. Air flows in from the blade ring bleed air passage 47a into this main bleed air passage 46e, and this air can be exhausted to the outer circumferential side of the casing main body 46. The bleed line 17a described with reference to Figure 1 is connected to this main bleed air passage 46e. Therefore, a portion of the air flowing along the negative pressure surface 52n of the blade body 51 flows into the cooling device 16 via the cavity 70 of the stator vane 50a, the blade ring bleed air passage 47e of the blade ring 47a, and the main body bleed air passage 46e of the casing main body 46, and is cooled and pressurized in this cooling device 16, after which it is sent to one of the multiple stator vane rows 38 of the turbine 30, and cools that stator vane row 38.

[0028] An area of ​​the negative pressure surface 52n with a predetermined width in the axial direction Da from the end of the radially outer side Dro of the negative pressure surface 52n to the end of the radially inner side Dri is an opening formation area 53. In this embodiment, the width in the axial direction Da of this opening formation area 53 is the same at any position in the radial direction Dr. In this opening formation area 53, inlet openings 55i are formed for each of the plurality of suction holes 55 aligned in the radial direction Dr and the axial direction Da.

[0029] As shown in FIG. 6 , the suction holes 55 are inclined with respect to the suction surface 52n so as to gradually extend toward the axial downstream side Dad from the inlet opening 55i toward the outlet opening 55o. The angle α of the direction in which the suction holes 55 having the inlet opening 55i extend relative to the suction surface 52n is preferably 20° or greater and 70° or less. In this embodiment, this angle α is 30°. The cross-sectional shape of the suction holes 55 on a plane perpendicular to the direction in which the suction holes 55 extend is circular. Therefore, the shapes of the inlet opening 55i and the outlet opening 55o are elliptical. Air flows along the suction surface 52n from the leading edge 51L to the trailing edge 51T. As described above, the extension direction of the suction holes 55 in this embodiment is inclined with respect to the plane in which the inlet opening 55i is formed. Therefore, in this embodiment, a portion of the air flowing along the suction surface 52n is more likely to flow into the cavity 70 through the suction holes 55.

[0030] The suction hole 55 has a minimum inner diameter d between the inlet opening 55i and the outlet opening 55o, and gradually increases in diameter from the minimum inner diameter d portion toward the inlet opening 55i, and also gradually increases in diameter from the minimum inner diameter d portion toward the outlet opening 55o. In this embodiment, some of the air flowing along the negative pressure surface 52n is likely to flow into the suction hole 55 via the inlet opening 55i. Furthermore, in this embodiment, the air that has flowed into the suction hole 55 is likely to flow into the cavity 70 from the outlet opening 55o.

[0031] The ratio (d / L) of the hole length L of the suction hole 55 to the minimum inner diameter d of the suction hole 55 is preferably 2 or less. Furthermore, the ratio (A2 / A1) of the area (A2) of the outlet opening 55o to the cross-sectional area A1 of the suction hole 55 at the position of the minimum inner diameter d is preferably 1.5 or less. Note that the area (A2) of the outlet opening 55o here is the area of ​​the outlet opening 55o in a direction perpendicular to the direction in which the suction hole 55 extends.

[0032] Here, as shown in Figure 4, the dimension of the blade body 51 in the axial direction (front-rear direction) Da is defined as Cx. The dimension of a% of this Cx is defined as a%Cx. The minimum inner diameter d of the suction hole 55 is preferably 0.8%Cx or more and 3.0%Cx or less. In this embodiment, the minimum inner diameter d of the suction hole 55 is, for example, 1.0%Cx. Furthermore, the central axis distance in the axial direction Da between two inlet openings 55i adjacent to each other in the axial direction Da, and the central axis distance in the radial direction Dr between two inlet openings 55i adjacent to each other in the radial direction Dr, are preferably, for example, 1.5% or more and 7.0% or less.

[0033] As described above, when the suction holes 55 are formed, part of the air flowing along the negative pressure surface 52 n is more likely to flow into the cavity 70 through the suction holes 55 .

[0034] An air boundary layer is formed along the suction surface 52n of the stator vane 50a. When this boundary layer develops, air resistance to the suction surface 52n increases, reducing the efficiency of the compressor 40. In this embodiment, a portion of the air flowing along the suction surface 52n flows into the cavity 70 of the stator vane 50a through the multiple suction holes 55 and is exhausted from the opening of this cavity 70. Therefore, in this embodiment, the development of the boundary layer is suppressed, the operating range of the compressor 40 is expanded, and the efficiency of the compressor 40 is improved.

[0035] As shown in Fig. 7 , the inventors performed a CFD (Computational Fluid Dynamics) analysis to determine the relationship between the incidence angle θ and pressure loss when the center position RC of the opening formation region 53 in the axial direction Da is set to the following position. Here, the incidence angle θ is the difference between the flow angle β and the blade angle κ at the leading edge 51L, as shown in the following equation: θ = β - κ As shown in Fig. 4 , the flow angle β here is the angle between a tangent line TL to the camber line CaL at the leading edge 51L and the air flow direction. Furthermore, the blade angle κ at the leading edge 51L is the angle between a tangent line TL to the camber line CaL at the leading edge 51L and a chord line ChL.

[0036] The center position RC of the opening formation region 53 is located at 30% Cx from the leading edge 51L (short dashed line in FIG. 7 ). The center position RC of the opening formation region 53 is located at 40% Cx from the leading edge 51L (two-dot chain line in FIG. 7 ). The center position RC of the opening formation region 53 is located at 50% Cx from the leading edge 51L (first embodiment, dashed line in FIG. 7 ). The center position RC of the opening formation region 53 is located at 60% Cx from the leading edge 51L (long dashed line in FIG. 7 ). In all of the above cases, the width of the opening formation region 53 in the axial direction Da is 20% Cx. For reference, FIG. 7 also shows a case where no suction hole 55 is formed in the negative pressure surface 52n (thick solid line in FIG. 7 ).

[0037] The CFD analysis revealed that when suction holes 55 are formed on suction surface 52n, the pressure loss is reduced compared to when suction holes 55 are not formed on suction surface 52n (thick solid line in FIG. 7), regardless of the incidence angle θ. This is because the thickness of the boundary layer formed along suction surface 52n is reduced.

[0038] In particular, it was found that the pressure loss was lower than in other examples when the center position RC of the opening formation region 53 in the axial direction Da was located 50% Cx from the leading edge 51L (dash-dotted line in FIG. 7 ) and when the center position RC of the opening formation region 53 in the axial direction Da was located 60% Cx from the leading edge 51L (long dashed line in FIG. 7 ). From this, it was found that the center position RC of the opening formation region 53 in the axial direction Da is preferably located within a range of 45% Cx to 65% Cx from the leading edge 51L, which range includes the positions 50% Cx from the leading edge 51L and 60% Cx from the leading edge 51L. Note that in this embodiment, the center position RC of the opening formation region 53 in the axial direction Da is located 50% Cx from the leading edge 51L.

[0039] When the center position RC of the opening formation region 53 in the axial direction Da is located at 50% Cx from the leading edge 51L, and when the center position RC of the opening formation region 53 in the axial direction Da is located at 60% Cx from the leading edge 51L, there is an incidence angle θ1 at which the pressure loss begins to increase sharply. This is thought to be because when the incidence angle θ is on the (+) side of this incidence angle θ1, a separation phenomenon occurs in which air separates from the suction surface 52n.

[0040] In the above example, the width of the opening formation region 53 in the axial direction Da is 20% Cx, but it has been found that the same tendency occurs when this width is set to 30% Cx or 40% Cx. From this, it can be seen that the position of the end of the opening formation region 53 on the axial upstream side Dau is at a position Dad on the axial downstream side of the position 30% Cx from the leading edge 51L.

[0041] Furthermore, the inventors have determined by CFD analysis the relationship between the incidence angle θ and pressure loss when the width of the blade-body cavity 72 in the axial direction Da is set to the following widths, as shown in Fig. 8: - The width W of the blade-body cavity 72 is 35% Cx (dashed line in Fig. 8) - The width W of the blade-body cavity 72 is 65% Cx (first embodiment, dashed line in Fig. 8) When the width W of the blade-body cavity 72 is 35% Cx, the position of the end of the axial upstream side Dau of the blade-body cavity 72 is 30% Cx from the leading edge 51L, and the position of the end of the axial downstream side Dad of the blade-body cavity 72 is 65% Cx from the leading edge 51L. Furthermore, when the width W of the blade-body cavity 72 is 65% Cx, the position of the end Dau on the axial upstream side of the blade-body cavity 72 is 15% Cx from the leading edge 51L, and the position of the end Dad on the axial downstream side of the blade-body cavity 72 is 80% Cx from the leading edge 51L.

[0042] As a result of the CFD analysis, it was found that the pressure loss is lower when the width of the blade-body cavity 72 in the axial direction Da is 65% Cx (dash-dotted line in FIG. 8 ) than when it is 35% Cx (dashed line in FIG. 8 ). This is thought to be because the resistance to the air flowing through the cavity 70 is reduced by increasing the width of the blade-body cavity 72 in the axial direction Da. It was also found that the incidence angle θ1 at which the pressure loss begins to increase sharply is shifted to the (+) side when the width of the blade-body cavity 72 in the axial direction Da is 65% Cx (dash-dotted line in FIG. 8 ) compared to when it is 35% Cx (dashed line in FIG. 8 ). This is also thought to be because the resistance to the air flowing through the blade-body cavity 72 is reduced by increasing the width of the blade-body cavity 72 in the axial direction Da. In this way, when the incidence angle θ1 at which the pressure loss begins to increase rapidly shifts to the (+) side, the range of operating conditions of the compressor 40 can be widened.

[0043] Based on the above findings, in this embodiment, the width of the blade-body cavity 72 in the axial direction Da is set to 65% Cx (indicated by the dashed line in FIG. 8). The width of the blade-body cavity 72 in the axial direction Da is preferably 60% Cx or more. Preferably, the position of the axial upstream end Dau of the blade-body cavity 72 is axially upstream Dau of the blade body 51 at a distance of 20% Cx from the leading edge 51L, and the position of the axial downstream end Dad of the blade-body cavity 72 is axially downstream Dad of the blade body 51 at a distance of 70% Cw from the leading edge 51L.

[0044] 5, the inner surface defining the cavity 70 has a plurality of partial inner surfaces that are connected to one another. Among the plurality of partial inner surfaces, the surfaces 76 at the corners of two adjacent partial inner surfaces are curved surfaces with a radius r of 3.5% Cx or more.

[0045] When air flowing along one partial inner surface passes through a corner and flows along another partial inner surface adjacent to the partial inner surface, turbulence such as a vortex occurs in the region along the other partial inner surface. When turbulence occurs, the resistance of the air flowing through the cavity 70 increases. Therefore, in this embodiment, the surface 76 of the corner is curved with a radius r of 3.5% Cx or more, thereby reducing turbulence and lowering the resistance of the air flowing through the cavity 70.

[0046] As described above, in this embodiment, the resistance of the air flowing through the cavity 70 is reduced, so that the air flows more easily through the cavity 70 .

[0047] Furthermore, in this embodiment, the air in the cavity 70 of the stator vane 50a is forcibly sucked in by the boost compressor 19 of the cooling device 16, so that some of the air flowing along the negative pressure surface 52n is more likely to flow into the cavity 70.

[0048] Therefore, in this embodiment, from the above viewpoint, the development of the boundary layer can be suppressed, and the efficiency of the compressor 40 can be improved.

[0049] Second Embodiment of Compressor Stator Vanes Hereinafter, a second embodiment of a compressor stator vane will be described.

[0050] 9, the configuration of the stator vane 50b in this embodiment is basically the same as the configuration of the stator vane 50a in the first embodiment. However, in this embodiment, the total areas of the inlet openings 55i differ between the multiple regions in the opening formation region 53.

[0051] In this embodiment, as in the first embodiment, an area having a predetermined width in the axial direction Da from the end of the radially outer side Dro of the negative pressure surface 52n to the end of the radially inner side Dri is the opening formation area 53. In this embodiment, the width in the axial direction Da of this opening formation area 53 is the same at any position in the radial direction Dr. In this opening formation area 53, inlet openings 55i are formed for each of the plurality of suction holes 55 aligned in the radial direction Dr and the axial direction Da.

[0052] The opening formation region 53 includes a first side region RO, an intermediate region RM, and a second side region RI. The length of the first side region RO in the blade height direction (radial direction) Dr, the length of the intermediate region RM in the blade height direction Dr, and the length of the second side region RI in the blade height direction Dr are all the same. The first side region RO is a region that includes the end of the first blade height side (radial outer side) Dro of the suction surface 52n, and will be referred to as the outer region RO hereinafter. The intermediate region RM is a region that includes a middle position in the blade height direction (radial direction) Dr on the suction surface 52n, and extends from the end of the second blade height side (radial inner side) Dri of the first side region (outer region) RO to the second blade height side (radial inner side) Dri. The second side region RI is a region extending from the end of the second blade height side (radially inner) Dri of the intermediate region RM to the end of the second blade height side (radially inner) Dri of the negative pressure surface 52n, and will be referred to as the inner region RI below.

[0053] In this embodiment, the density of the inlet openings 55i in the middle region RM is the same as the density of the inlet openings 55i in the outer region RO. In this embodiment, the density of the inlet openings 55i in the inner region RI is higher than the density of the inlet openings 55i in the middle region RM and the density of the inlet openings 55i in the outer region RO. Thus, in this embodiment, the total area of ​​the inlet openings 55i in the inner region RI is larger than the total area of ​​the inlet openings 55i in the middle region RM.

[0054] The inventors performed CFD analysis to determine the relationship between the incidence angle θ and pressure loss when the center position RC of the opening formation region 53 in the axial direction Da and the opening density of the inner region RI are set as follows, as shown in FIG. 10 : The center position RC of the opening formation region 53 is located 50% Cx from the leading edge 51L, and the opening density of the inner region RI is not high (first embodiment, dashed line in FIG. 10 ). The center position RC of the opening formation region 53 is located 50% Cx from the leading edge 51L, and the opening density of the inner region RI is high (Ih) (second embodiment, dashed line in FIG. 10 ). Note that, in the above, "the opening density of the inner region RI is not high" means that the density of the inlet openings 55i in the inner region RI is the same as the density of the inlet openings 55i in the middle region RM and the density of the inlet openings 55i in the outer region RO. In both of the above cases, the width of the opening formation region 53 in the axial direction Da is 20% Cx. Furthermore, the pressure loss for the incidence angle θ indicated by the dashed dotted line in FIG. 10 is the pressure loss under the same conditions as when the pressure loss for the incidence angle θ indicated by the dashed dotted line in FIG. 7 was determined, and is therefore the same as the pressure loss for the incidence angle θ indicated by the dashed dotted line in FIG. 7.

[0055] As a result of the CFD analysis, it was found that when the density of the inlet openings 55i of the inner region RI is increased (dashed line in Figure 10), the pressure loss decreases and the incidence angle θ1' at which the pressure loss begins to increase rapidly shifts to the (+) side compared to when the density of the inlet openings 55i of the inner region RI is not increased (dashed line in Figure 10).

[0056] In the case where a boundary layer is likely to develop around the inner region RI in the negative pressure surface 52n, by increasing the density of the inlet opening 55i of the inner region RI as described above, the development of the boundary layer can be suppressed, the pressure loss can be kept low, and the efficiency of the compressor 40 can be improved.

[0057] Depending on the operating conditions of the compressor 40 and the number of stages of the stator vane row 48a, a boundary layer may be likely to develop around the outer region RO of the suction surface 52n. In this case, by increasing the density of the inlet openings 55i of the outer region RO, the development of the boundary layer can be suppressed, pressure loss can be kept low, and the efficiency of the compressor 40 can be improved. Depending on the operating conditions of the compressor 40 and the number of stages of the stator vane row 48a, a boundary layer may be likely to develop around the inner region RI and outer region RO of the suction surface 52n. In this case, by increasing the density of the inlet openings 55i of the inner region RI and outer region RO, the development of the boundary layer can be suppressed, pressure loss can be kept low, and the efficiency of the compressor 40 can be improved.

[0058] Third and Fourth Embodiments of Compressor Stator Vanes Hereinafter, third and fourth embodiments of the compressor stator vanes will be described.

[0059] 11 and 12 , the configurations of the stator vanes 50 c, 50 d in the third and fourth embodiments are basically the same as the configuration of the stator vane 50 a in the first embodiment. However, in the third and fourth embodiments, the shape of the opening formation region 53 and the total area of ​​the inlet openings 55 i among the multiple regions in the opening formation region 53 are different.

[0060] 11 , in the stator vane 50c of the third embodiment, as in the first embodiment, a region of a predetermined width in the axial direction Da from the end of the radially outer side Dro of the suction surface 52n to the end of the radially inner side Dri is an opening formation region 53. A center position RC of this opening formation region 53 is located at a distance of 50% Cx from the leading edge 51L.

[0061] The opening formation region 53 in the third embodiment includes a first side region RO (outer region RO), a middle region RM, and a second side region RI (inner region RI), similar to the second embodiment.

[0062] In the third embodiment, the width in the axial direction Da in the outer region RO and the width in the axial direction Da in the region on the first blade height side (radially outer side) Dro of the intermediate region RM are the same at any position in the radial direction Dr, for example, 10% Cx. On the other hand, the width in the axial direction Da in the region on the second blade height side (radially inner side) Dri of the intermediate region RM increases toward the radially inner side Dri. The width in the axial direction Da in the inner region RI also increases toward the radially inner side Dri. Therefore, the shape of the inner region RI is an isosceles trapezoid, in other words, a pyramidal shape. The width in the axial direction Da at the edge on the radially outer side Dro of the inner region RI is the same as the width in the axial direction Da at the edge on the radially inner side Dri of the intermediate region RM. The width in the axial direction Da at the edge on the radially inner side Dri of the inner region RI is, for example, 40% Cx. The position of the end of the axial upstream side Dau in this opening formation region 53 is on the radially inner side Dri of the inner region RI and at the edge of the axial upstream side Dau, 30% Cx from the leading edge 51L.

[0063] In the third embodiment, the density of the inlet openings 55i in the middle region RM is the same as the density of the inlet openings 55i in the outer region RO. In the third embodiment, the density of the inlet openings 55i in the inner region RI is higher than the density of the inlet openings 55i in the middle region RM and the density of the inlet openings 55i in the outer region RO. Furthermore, in the inner region RI, the number of inlet openings 55i gradually increases toward the radially inner side Dri. Therefore, the number of inlet openings 55i in the inner region RI is greater than the number of inlet openings 55i in the middle region RM and the number of inlet openings 55i in the outer region RO. Therefore, in the third embodiment, the total area of ​​the inlet openings 55i in the inner region RI is greater than the total area of ​​the inlet openings 55i in the middle region RM and the total area of ​​the inlet openings 55i in the outer region RO.

[0064] 12 , in the stator vane 50d of the fourth embodiment, as in the first embodiment, a region of a predetermined width in the axial direction Da from the end of the radially outer side Dro of the suction surface 52n to the end of the radially inner side Dri is an opening formation region 53. A center position RC of this opening formation region 53 is located at a position 50% Cx from the leading edge 51L.

[0065] The opening formation region 53 in the fourth embodiment includes a first side region RO (outer region RO), a middle region RM, and a second side region RI (inner region RI), similar to the second and third embodiments.

[0066] In the fourth embodiment, the width in the axial direction Da of the intermediate region RM is the same at any position in the radial direction Dr, for example, 10% Cx. Meanwhile, the width in the axial direction Da of the outer region RO gradually increases toward the radially outer side Dro. Therefore, the shape of the outer region RO is an isosceles trapezoid, in other words, an inverted pyramid. The width in the axial direction Da of the outer region RO at the radially inner edge Dri is the same as the width in the axial direction Da of the intermediate region RM. Meanwhile, the width in the axial direction Da of the outer region RO at the radially outer edge Dro is, for example, 40% Cx. Furthermore, the width in the axial direction Da of the inner region RI increases toward the radially inner side Dri. Therefore, the shape of the inner region RI is an isosceles trapezoid, in other words, a pyramid. The width in the axial direction Da of the inner region RI at the radially outer edge Dro is the same as the width in the axial direction Da of the intermediate region RM. Meanwhile, the width in the axial direction Da at the edge of the radially inner side Dri of the inner region RI is, for example, 40% Cx. The position of the end of the axial upstream side Dau in the opening formation region 53 is the position of the edge of the axially upstream side Dau on the radially inner side Dri of the inner region RI, and also the position of the edge of the axially upstream side Dau on the radially outer side Dro of the outer region RO. This position is 30% Cx from the leading edge 51L.

[0067] In the fourth embodiment, the density of the inlet openings 55i in the outer region RO is higher than the density of the inlet openings 55i in the middle region RM. Furthermore, in the outer region RO, the number of inlet openings 55i gradually increases toward the radially outer side Dro. Therefore, the number of inlet openings 55i in the outer region RO is greater than the number of inlet openings 55i in the middle region RM. Also, in the fourth embodiment, the density of the inlet openings 55i in the inner region RI is higher than the density of the inlet openings 55i in the middle region RM. Furthermore, in the inner region RI, the number of inlet openings 55i gradually increases toward the radially inner side Dri. Therefore, the number of inlet openings 55i in the inner region RI is greater than the number of inlet openings 55i in the middle region RM. Therefore, in the fourth embodiment, the total area of ​​the inlet openings 55i in the inner region RI and the total area of ​​the inlet openings 55i in the outer region RO are greater than the total area of ​​the inlet openings 55i in the middle region RM.

[0068] 13 , the inventors have used CFD analysis to determine the relationship between the incidence angle θ and pressure loss when the shape of each region in the opening formation region 53 and the opening density of each region are as follows: - The center position RC of the opening formation region 53 is 50% Cx from the leading edge 51L, and the opening density of each region is the same (first embodiment, dashed line in FIG. 13 ); - The center position RC of the opening formation region 53 is 50% Cx from the leading edge 51L, the shape of the inner region RI is pyramidal, and the opening density of this inner region RI is not high (Ip) (short dashed line in FIG. 13 ); - The center position RC of the opening formation region 53 is 50% Cx from the leading edge 51L, the shape of the inner region RI is pyramidal, and the opening density of this inner region RI is high (Iph) (third embodiment, dashed line in FIG. 13 ). - The center position RC of the opening formation region 53 is 50% Cx from the leading edge 51L, the shapes of the inner region RI and outer region RO are pyramidal, and the opening density of the inner region RI and outer region RO is not high (Ip-Op) (thin solid line in Figure 13). - The center position RC of the opening formation region 53 is 50% Cx from the leading edge 51L, the shapes of the inner region RI and outer region RO are pyramidal, and the opening density of the inner region RI and outer region RO is high (Iph-Oph) (fourth embodiment, long dashed line in Figure 13). Note that in the above, "the opening density of the aa region is not high" means that the density of the inlet openings 55i in the aa region is the same as the density of the inlet openings 55i in the intermediate region RM.

[0069] As a result of the CFD analysis, it was found that when the shape of the inner region RI and / or the outer region RO is made pyramidal and the number of inlet openings 55i in these regions is increased (short dashed line, two-dot chain line, thin solid line, long dashed line in Figure 13), the incidence angles θ1', θ" at which pressure loss begins to increase rapidly are shifted to the (+) side compared to when the width of the opening formation region 53 in the axial direction Da is the same at any position in the radial direction Dr (dash-dotted line in Figure 13). In particular, it was found that when the shape of the inner region RI and the outer region RO is made pyramidal and the density of the inlet openings 55i in these regions is increased (long dashed line in Figure 13c), the incidence angle θ" at which pressure loss begins to increase rapidly is shifted to the (+) side compared to when the shape of the inner region RI and the outer region RO is made pyramidal and the density of the inlet openings 55i in these regions is not high (thin solid line).

[0070] When a boundary layer is likely to develop around the inner region RI in the suction surface 52n, by making the number of inlet openings 55i in the inner region RI greater than the number of inlet openings 55i in the intermediate region RM as in the third embodiment, it is possible to suppress the development of the boundary layer, keep pressure loss low, and improve the efficiency of the compressor 40. In particular, by making the number of inlet openings 55i in the inner region RI greater than the number of inlet openings 55i in the intermediate region RM and increasing the density of the inlet openings 55i in the inner region RI greater than the density of the inlet openings 55i in the intermediate region RM as in the third embodiment, it is possible to further suppress the development of the boundary layer, keep pressure loss low, and improve the efficiency of the compressor 40.

[0071] In addition, when a boundary layer is likely to develop around the inner region RI in the negative pressure surface 52n, it is sufficient to make the number of inlet openings 55i in the inner region RI greater than the number of inlet openings 55i in the intermediate region RM, and it is not necessary to increase the density of the inlet openings 55i in the inner region RI greater than the density of the inlet openings 55i in the intermediate region RM, as in the third embodiment.

[0072] In addition, when a boundary layer is likely to develop around the outer region RO in the suction surface 52 n, the outer region RO may be formed in a pyramidal shape, and the number of inlet openings 55 i in the outer region RO may be made greater than the number of inlet openings 55 i in the intermediate region RM. In this case, too, the density of the inlet openings 55 i in the outer region RO may be made higher than the density of the inlet openings 55 i in the intermediate region RM.

[0073] When a boundary layer is likely to develop around the inner region RI and the outer region RO on the negative pressure surface 52n, it is sufficient to make the number of inlet openings 55i in the inner region RI and the outer region RO greater than the number of inlet openings 55i in the intermediate region RM, and it is not necessary to increase the density of the inlet openings 55i in the inner region RI and the outer region RO greater than the density of the inlet openings 55i in the intermediate region RM, as in the fourth embodiment.

[0074] Fifth Embodiment of Compressor Stator Vanes Hereinafter, a fifth embodiment of a compressor stator vane will be described.

[0075] 14 to 16, the configuration of the stator vane 50e in the fifth embodiment is basically the same as the configuration of the stator vane 50a in the first embodiment. However, in the fifth embodiment, a plurality of suction holes 66 are formed in the outer shroud 61o and the inner shroud 61i.

[0076] The suction holes 66 of the outer shroud 61o have an inlet opening 66i that opens in the gas path surface 62o of the outer shroud 61o and an outlet opening 66o that opens on an outer inner surface 71p that is back-to-back with the gas path surface 62o among the inner surfaces that define the outer cavity 71. Thus, the suction holes 66 penetrate from the gas path surface 62o to the outer inner surface 71p that defines a portion of the outer cavity 71. The suction holes 66 of the inner shroud 61i have an inlet opening 66i that opens in the gas path surface 62i of the inner shroud 61i and an outlet opening 66o that opens on an inner inner surface 73p that is back-to-back with the gas path surface 62i among the inner surfaces that define the inner cavity 73. Thus, the suction holes 66 penetrate from the gas path surface 62i to the inner inner surface 73p that defines a portion of the inner cavity 73.

[0077] In this embodiment, an opening formation region 65o is formed in the gas path surface 62o of the outer shroud 61o by a region along the suction surface 52n on the circumferential suction side Dcn with respect to the blade body 51. In the opening formation region 65o, inlet openings 66i are formed for each of the plurality of suction holes 66 aligned in the circumferential direction Dc and the axial direction Da.

[0078] In the present embodiment, an opening formation region 65i is formed in the gas path surface 62i of the inner shroud 61i by a region along the suction surface 52n on the circumferential suction side Dcn with respect to the blade body 51. In the opening formation region 65i, inlet openings 66i are formed for each of the plurality of suction holes 66 aligned in the circumferential direction Dc and the axial direction Da.

[0079] The axial upstream end Dau of the opening formation region 65o in the gas path surface 62o of the outer shroud 61o and the axial upstream end Dau of the opening formation region 65i in the gas path surface 62i of the inner shroud 61i are preferably located closer to the trailing edge 51T than a position that is 30% Cx from the leading edge 51L. In the present embodiment, the axial upstream end Dau of the opening formation region 65o in the gas path surface 62o of the outer shroud 61o and the axial upstream end Dau of the opening formation region 65i in the gas path surface 62i of the inner shroud 61i are located at a position that is 40% Cx from the leading edge 51L, similar to the opening formation region 53 in the suction surface 52n in the first embodiment.

[0080] The suction holes 66 of the outer shroud 61o and the suction holes 66 of the inner shroud 61i are inclined with respect to the gas path surfaces 62o, 62i so as to gradually extend from their inlet openings 66i toward their outlet openings 66o toward the axial downstream side Dad, similar to the suction holes 55 of the blade body 51 described with reference to Fig. 6. The angle α of the direction in which the suction holes 66 having the inlet openings 66i extend with respect to the gas path surfaces 62o, 62i is preferably 20° or more and 70° or less. In this embodiment, this angle α is 30°.

[0081] Like the suction holes 55 of the blade body 51, the suction holes 66 of the outer shroud 61o and the suction holes 66 of the inner shroud 61i have a minimum inner diameter d in the portion between the inlet opening 66i and the outlet opening 66o, and gradually increase in diameter from the portion of minimum inner diameter d toward the inlet opening 66i, and also gradually increase in diameter from the portion of minimum inner diameter d toward the outlet opening 66o.

[0082] As with the suction hole 55 of the blade body 51, the suction hole 66 of the outer shroud 61o and the suction hole 66 of the inner shroud 61i preferably have a ratio (d / L) of the hole length L of the suction hole 66 to the minimum inner diameter d of 2 or less. Also, the ratio (A2 / A1) of the area (A2) of the outlet opening 66o to the cross-sectional area A1 of the suction hole 66 at the position of the minimum inner diameter d is preferably 1.5 or less.

[0083] 17 , the inventors have performed CFD analysis to determine the relationship between the incidence angle θ and pressure loss when the presence or absence of suction holes 66 in the outer shroud 61o and the inner shroud 61i is determined as follows: - The center position RC of the opening formation region 53 in the suction surface 52n is located at 50% Cx from the leading edge 51L, and no suction holes 66 are formed in the outer shroud 61o and the inner shroud 61i (first embodiment, dashed line in FIG. 17 ). - The center position RC of the opening formation region 53 is located at 50% Cx from the leading edge 51L, and the suction holes 66 are formed in the outer shroud 61o and the inner shroud 61i (+IE+OE) (fifth embodiment, dashed line in FIG. 17 ).

[0084] As a result of the CFD analysis, it was found that when the suction holes 66 are formed in the outer shroud 61 o and the inner shroud 61 i (dashed line in FIG. 17 ), the incidence angle θ1′ at which the pressure loss begins to increase rapidly shifts to the negative side compared to when the suction holes 66 are not formed in the outer shroud 61 o and the inner shroud 61 i (chain line in FIG. 17 ).

[0085] Therefore, in this embodiment, within a wide range of the incidence angle θ, it is possible to suppress the development of the boundary layer and keep the pressure loss low, thereby improving the efficiency of the compressor 40.

[0086] Although this embodiment is an example in which the suction holes 66 are formed in the outer shroud 61 o and the inner shroud 61 i of the stator vane 50 a in the first embodiment, the suction holes 66 may be formed in the outer shroud 61 o and the inner shroud 61 i of the stator vanes 50 b, 50 c, and 50 d in all of the examples described above. In this case, too, the same effects as those of this embodiment can be obtained.

[0087] In addition, in the present embodiment, the suction holes 66 are formed in both the outer shroud 61o and the inner shroud 61i of the stator vane 50e. However, if a boundary layer is likely to develop around the radially inner region Dri on the suction surface 52n, the suction holes 66 may be formed only in the inner shroud 61i of the inner shroud 61i and the outer shroud 61o of the stator vanes 50a, 50b, 50c, 50d, and 50e in all the examples described above, including this embodiment. Also, if a boundary layer is likely to develop around the radially outer region Dro on the suction surface 52n, the suction holes 66 may be formed only in the outer shroud 61o of the inner shroud 61i and the outer shroud 61o of the stator vanes 50a, 50b, 50c, 50d, and 50e in all the examples described above, including this embodiment.

[0088] "Modifications" In the above examples, the shapes of the inlet openings 55i, 66i and the outlet openings 55o, 66o are elliptical. However, the shapes of the inlet openings 55i, 66i and the outlet openings 55o, 66o are not limited to elliptical and may be, for example, rectangular.

[0089] In the above example, the cavity 70 opens at the front end surface 64f of the outer shroud 61o. However, the cavity 70 may open at any surface other than the gas path surface 62o of the outer shroud 61o, for example, at the outer opposite gas path surface 63o of the outer shroud 61o.

[0090] In the above example, the suction holes 55, 66 are formed in the plurality of stator vanes 50a, 50b, 50c, 50d, and 50e that constitute some of the stator vane rows 48a out of the plurality of stator vane rows 48, 48a. However, for example, the suction holes 55, 66 may be formed not only in one stator vane row 48a but also in the plurality of stator vanes that constitute all of the stator vane rows 48 downstream of this one stator vane row 48a. Furthermore, the suction holes 55, 66 may be formed in the plurality of stator vanes that constitute all of the stator vane rows 48, 48a.

[0091] The compressor 40 in the above example is the compressor of the gas turbine 10. However, the compressor does not have to be the compressor 40 of the gas turbine 10 as long as the compressor is a multi-stage axial compressor.

[0092] Furthermore, the present disclosure is not limited to the embodiment and modifications described above, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention derived from the content defined in the claims and their equivalents.

[0093] "Additional Notes" The compressor stator vanes 50a, 50b, 50c, 50d, and 50e in the above embodiments and modified examples can be understood, for example, as follows: (1) The compressor stator vanes 50a, 50b, 50c, 50d, and 50e in a first aspect include a blade body 51 having an airfoil-shaped cross section and extending in a blade height direction Dr including a directional component perpendicular to the cross section, a first shroud 61o provided at an end of the blade height first side Dro of a blade height first side Dro and a blade height second side Dri of the blade body 51 in the blade height direction Dr, and a second shroud 61i provided at an end of the blade height second side Dri of the blade body 51. The blade body 51 has a leading edge 51L, a trailing edge 51T, a pressure surface 52p connecting the leading edge 51L and the trailing edge 51T, and a suction surface 52n connecting the leading edge 51L and the trailing edge 51T and in a back-to-back relationship with the pressure surface 52p. The first shroud 61o has a first gas path surface 62o facing the blade height second side Dri and extending in a direction including a directional component perpendicular to the blade height direction Dr from an end of the blade height first side Dro of the blade body 51, a first counter-gas path surface 63o facing the blade height first side Dro and in a back-to-back relationship with the first gas path surface 62o, and a first side peripheral surface 64o connecting an edge of the first gas path surface 62o and an edge of the first counter-gas path surface 63o. The second shroud 61i has a second gas path surface 62i facing the blade height first side Dro and extending in a direction including a directional component perpendicular to the blade height direction Dr from an end of the blade height second side Dri of the blade body 51, and a second counter-gas path surface 63i facing the blade height second side Dri and facing back-to-back with the second gas path surface 62i. A cavity 70 is formed in the blade body 51 and the first shroud 61o, the cavity 70 being continuous within the blade body 51 and the first shroud 61o and opening at the first counter-gas path surface 63o or the first side peripheral surface 64o. The blade body 51 has an inlet opening 55i opening at the suction surface 52n and an outlet opening 55o opening at an inner surface defining the cavity 70, and a plurality of suction holes 55 penetrating from the suction surface 52n to the inner surface defining the cavity 70.An area of ​​a predetermined width in the suction surface 52n in the longitudinal direction Da where the leading edge 51L and the trailing edge 51T are aligned and which extends from the end of the first blade height side Dro to the end of the second blade height side Dri on the suction surface 52n forms an opening formation area 53. In the opening formation area 53, the inlet openings 55i are formed for each of the plurality of suction holes 55 aligned in the blade height direction Dr and the longitudinal direction Da.

[0094] An air boundary layer is formed along the suction surface 52n of each of the stator vanes 50a, 50b, 50c, 50d, and 50e. When this boundary layer develops, air resistance to the suction surface 52n increases, reducing the efficiency of the compressor 40. In this configuration, a portion of the air flowing along the suction surface 52n flows into the cavity 70 of each of the stator vanes 50a, 50b, 50c, 50d, and 50e through the multiple suction holes 55 and is exhausted from the opening of the cavity 70. This configuration therefore suppresses the development of the boundary layer, thereby expanding the operating range of the compressor and improving the compressor efficiency. In particular, in this configuration, the inlet openings 55i are formed for each of the multiple suction holes 55 aligned in the blade height direction Dr and the longitudinal direction Da throughout the entire opening formation region 53, where the boundary layer is likely to develop. This effectively suppresses the development of the boundary layer while limiting the number of suction holes 55.

[0095] (2) In a second aspect, the compressor stator vane 50b, 50c, 50d of the compressor stator vane 50b, 50c, 50d of the first aspect has the opening formation region 53 including a first side region RO including an end of the blade height first side Dro of the suction surface 52n, an intermediate region RM including an intermediate position in the blade height direction Dr on the suction surface 52n and extending from the end of the blade height second side Dri of the first side region RO to the blade height second side Dri, and a second side region RI extending from the end of the blade height second side Dri of the intermediate region RM to the end of the blade height second side Dri of the suction surface 52n. A total area of ​​the inlet openings 55i in at least one of the first side region RO and the second side region RI is larger than a total area of ​​the inlet openings 55i in the intermediate region RM.

[0096] Depending on the position of the stator vane in the compressor and the operating conditions of the compressor, a boundary layer may be likely to develop around the first region RO of the suction surface 52n, a boundary layer may be likely to develop around the second region RI of the suction surface 52n, or a boundary layer may be likely to develop around the first region RO and the second region RI of the suction surface 52n. Therefore, when a boundary layer is likely to develop around the first region RO of the suction surface 52n, the total area of ​​the inlet openings 55i in the first region RO can be made larger than the total area of ​​the inlet openings 55i in the intermediate region RM, thereby effectively suppressing the development of the boundary layer and keeping pressure loss low. Furthermore, when a boundary layer is likely to develop around the second region RI of the suction surface 52n, the total area of ​​the inlet openings 55i in the second region RI can be made larger than the total area of ​​the inlet openings 55i in the intermediate region RM, thereby effectively suppressing the development of the boundary layer and keeping pressure loss low. In addition, when a boundary layer is likely to develop around the first side region RO and the second side region RI on the negative pressure surface 52n, the development of the boundary layer can be effectively suppressed and pressure loss can be kept low by making the total area of ​​the inlet openings 55i in the first side region RO and the total area of ​​the inlet openings 55i in the second side region RI larger than the total area of ​​the inlet openings 55i in the intermediate region RM.

[0097] (3) In the compressor stator vanes 50b, 50c, and 50d of the third aspect, in the compressor stator vanes 50b, 50c, and 50d of the second aspect, the number of the inlet openings 55i in the at least one side region is greater than the number of the inlet openings 55i in the intermediate region RM, and the density of the inlet openings 55i in the at least one side region is higher than the density of the inlet openings 55i in the intermediate region RM.

[0098] By making the number of inlet openings 55i in at least one side region greater than the number of inlet openings 55i in the intermediate region RM, the total area of ​​the inlet openings 55i in at least one side region can be made greater than the total area of ​​the inlet openings 55i in the intermediate region RM. Also, by making the density of the inlet openings 55i in at least one side region greater than the density of the inlet openings 55i in the intermediate region RM, the total area of ​​the inlet openings 55i in at least one side region can be made greater than the total area of ​​the inlet openings 55i in the intermediate region RM.

[0099] (4) In the compressor stator vane 50c, 50d of the fourth aspect, in the compressor stator vane 50c, 50d of the second aspect, the width in the front-rear direction Da in the at least one side region gradually increases with increasing distance from the intermediate region RM in the blade height direction Dr. The maximum width in the front-rear direction Da in the at least one side region is wider than the maximum width in the front-rear direction Da in the intermediate region RM. The number of the inlet openings 55i in the at least one side region gradually increases with increasing distance from the intermediate region RM in the blade height direction Dr and is greater than the number of the inlet openings 55i in the intermediate region RM. The density of the inlet openings 55i in the at least one side region is higher than the density of the inlet openings 55i in the intermediate region RM.

[0100] By making the maximum width in the front-rear direction Da in at least one side region wider than the maximum width in the front-rear direction Da in the intermediate region RM and by making the number of inlet openings 55i in at least one side region greater than the number of inlet openings 55i in the intermediate region RM, in this aspect, the total area of ​​the inlet openings 55i in at least one side region can be made greater than the total area of ​​the inlet openings 55i in the intermediate region RM. Therefore, in this aspect, when a boundary layer is likely to develop in at least one of the portions on the first blade height side Dro and the second blade height side Dri of the suction surface 52n, the development of the boundary layer in at least one of the portions on the first blade height side Dro and the second blade height side Dri can be effectively suppressed.

[0101] (5) A compressor stator vane 50d in a fifth aspect is the compressor stator vane 50d in any one of the second to fourth aspects, wherein the at least one side region includes the first side region RO and the second side region RI.

[0102] (6) Compressor stator vanes 50a, 50b, 50c, 50d, and 50e in a sixth aspect: In the compressor stator vanes 50a, 50b, 50c, 50d, and 50e in any one of the first to fifth aspects, a center position RC in the longitudinal direction Da of the opening formation region 53 is a position within a range of 45% to 65% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L.

[0103] On the suction surface 52n, the center position RC in the longitudinal direction Da of the region where the boundary layer is likely to develop is a position within a range from the leading edge 51L of 45% to 65% of the width in the longitudinal direction Da of the blade body 51. In this embodiment, the center position RC of the opening formation region 53 is at the center position RC of the region where the boundary layer is likely to develop, so that the development of the boundary layer can be effectively suppressed while keeping the number of suction holes 55 small.

[0104] (7) Compressor stator vanes 50a, 50b, 50c, 50d, and 50e in a seventh aspect are as follows: In the compressor stator vanes 50a, 50b, 50c, 50d, and 50e in the sixth aspect, the position of the end of the opening formation region 53 on the side of the leading edge 51L in the longitudinal direction Da is closer to the trailing edge 51T than a position that is 30% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L.

[0105] The position of the end of the suction surface 52n on the leading edge 51L side in the longitudinal direction Da of the region where the boundary layer is likely to develop is closer to the trailing edge 51T than a position that is 30% of the width of the wing body 51 in the longitudinal direction Da from the leading edge 51L. In this embodiment, the position of the end of the opening formation region 53 on the leading edge 51L side is closer to the trailing edge 51T than a position that is 30% of the width of the wing body 51 in the longitudinal direction Da from the leading edge 51L, so that the development of the boundary layer can be effectively suppressed while keeping the number of suction holes 55 small.

[0106] (8) A compressor stator vane 50e according to an eighth aspect is the compressor stator vane 50e according to any one of the first to seventh aspects, wherein at least one of the first shroud 61o and the second shroud 61i has an inlet opening 66i opening in a gas path surface 62o, 62i of the at least one shroud and an outlet opening 55o opening on the inner surface that defines the cavity 70. A plurality of suction holes 66 are formed penetrating from the gas path surface 62o, 62i to the inner surface that defines the cavity 70. A side of the pressure surface 52p on which the suction surface 52n exists is a suction side Dcn. In the gas path surface 62o, 62i of the at least one shroud, a region on the suction side Dcn and along the suction surface 52n with respect to the blade body 51 forms an opening formation region 65o, 65i. The inlet openings 66i are formed in the opening formation regions 65o, 65i in the gas path surfaces 62o, 62i of the at least one shroud, for each of the plurality of suction holes 66 formed in the at least one shroud.

[0107] In this aspect, when a boundary layer is likely to develop in at least one of the blade height first side Dro portion and the blade height second side Dri portion of the negative pressure surface 52n, the development of the boundary layer in at least one of the blade height first side Dro portion and the blade height second side Dri portion can be effectively suppressed.

[0108] (9) A ninth aspect of the compressor stator vane 50e is the compressor stator vane 50e of the eighth aspect, wherein the end of the opening formation region 65o, 65i in the gas path surface 62o, 62i of the at least one shroud on the side of the leading edge 51L in the longitudinal direction Da is located closer to the trailing edge 51T than a position that is 30% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L.

[0109] On the suction surface 52n, the position of the end on the leading edge 51L side in the longitudinal direction Da of the region where the boundary layer is likely to develop is closer to the trailing edge 51T than a position that is 30% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L. In this aspect, the positions of the ends of the opening formation regions 65o, 65i on the leading edge 51L side are closer to the trailing edge 51T than a position that is 30% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L. Therefore, in this aspect, the development of the boundary layer can be effectively suppressed while keeping the number of suction holes 66 small.

[0110] (10) In a tenth aspect, in the compressor stator vane 50a, 50b, 50c, 50d, 50e of the compressor stator vane 50a, 50b, 50c, 50d, 50e of any one of the first to ninth aspects, each of the plurality of suction holes 55, 66 is inclined with respect to a plane on which the inlet openings 55i, 66i are formed so as to gradually extend from the leading edge 51L side toward the trailing edge 51T side in the longitudinal direction Da as it moves from the inlet openings 55i, 66i toward the outlet openings 55o, 66o. The angle of the direction in which the plurality of suction holes 55, 66 extend with respect to the plane on which the inlet openings 55i, 66i are formed is 20° or more and 70° or less. Each of the plurality of suction holes 55, 66 has a minimum inner diameter d in the portion between the inlet opening 55i, 66i and the outlet opening 55o, 66o, and gradually increases in diameter from the portion with the minimum inner diameter d toward the inlet opening 55i, 66i, and also gradually increases in diameter from the portion with the minimum inner diameter d toward the outlet opening 55o, 66o.

[0111] Air flows from the leading edge 51L side to the trailing edge 51T side along the surface on which the inlet openings 55i, 66i are formed. The suction holes 55, 66 in this embodiment are inclined with respect to the surface on which the inlet openings 55i, 66i are formed so as to gradually extend from the leading edge 51L side to the trailing edge 51T side as they move from the inlet openings 55i, 66i toward the outlet openings 55o, 66o. Therefore, in this embodiment, some of the air flowing along the surface on which the inlet openings 55i, 66i are formed is easily introduced into the cavity 70 through the suction holes 55, 66. Furthermore, in this embodiment, the diameter gradually increases from the portion of the minimum inner diameter d toward the inlet openings 55i, 66i, so that some of the air flowing along the surface on which the inlet openings 55i, 66i are formed is easily introduced into the suction holes 55, 66 through the inlet openings 55i, 66i. In addition, in this embodiment, the diameter gradually increases from the portion with the smallest inner diameter d toward the outlet openings 55o, 66o, so that air that flows into the suction holes 55, 66 can easily flow into the cavity 70 from the outlet openings 55o, 66o.

[0112] (11) In the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of an eleventh aspect, in the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of the tenth aspect, the ratio of the hole length of each of the plurality of suction holes 55, 66 to the minimum inner diameter d of each of the plurality of suction holes 55, 66 is 2 or less.

[0113] In this embodiment, air flows easily through the suction holes 55 and 66 .

[0114] (12) In a twelfth aspect, in the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of the tenth or eleventh aspect, a ratio (A2 / A1) of an area A2 of the outlet openings 55o, 66o to a cross-sectional area A1 of the suction holes 55, 66 at the position of the minimum inner diameter d is 1.5 or less. The area of ​​the outlet openings 55o, 66o is an area in a direction perpendicular to a direction in which the suction holes 55, 66 having the outlet openings 55o, 66o extend.

[0115] (13) The compressor stator vanes 50a, 50b, 50c, 50d, and 50e in a thirteenth aspect are the compressor stator vanes 50a, 50b, 50c, 50d, and 50e in any one of the first to twelfth aspects, wherein the minimum inner diameter d of each of the plurality of suction holes 55, 66 is 0.8% or more and 3.0% or less of the width of the blade body 51 in the fore-and-aft direction Da.

[0116] (14) In the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of a fourteenth aspect, in the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of any one of the first to thirteenth aspects, the central axis distance between two adjacent suction holes 55, 66 among the plurality of suction holes 55, 66 is 1.5% or more and 7.0% or less of the width of the blade body 51 in the fore-and-aft direction Da.

[0117] (15) In the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of a fifteenth aspect, in the compressor stator vanes 50a, 50b, 50c, 50d, and 50e of any one of the first to fourteenth aspects, the inner surface defining the cavity 70 has a plurality of partial inner surfaces that are connected to each other. Among the plurality of partial inner surfaces, surfaces 76 at corners of two adjacent partial inner surfaces are curved surfaces with a radius r that is 3.5% or more of the width of the blade body 51 in the longitudinal direction Da.

[0118] When air flowing along one partial inner surface passes through a corner and flows along another partial inner surface adjacent to the partial inner surface, turbulence such as a vortex occurs in the region along the other partial surface. When turbulence occurs, the resistance of the air flowing through the cavity 70 increases. Therefore, in this embodiment, the surface 76 of the corner is curved with a radius r that is 3.5% or more of the width of the wing body 51 in the longitudinal direction Da, thereby reducing turbulence and lowering the resistance of the air flowing through the cavity 70.

[0119] (16) The compressor stator vane 50a, 50b, 50c, 50d, 50e in a sixteenth aspect is the compressor stator vane 50a, 50b, 50c, 50d, 50e in any one of the first to fifteenth aspects, wherein the width in the longitudinal direction Da of a blade-body cavity 72, which is a portion of the cavity 70 formed in the blade body 51, is 60% or more of the width of the blade body 51 in the longitudinal direction Da. The position of the end of the blade-body cavity 72 on the leading edge 51L side is closer to the leading edge 51L than a position that is 20% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L. The position of the end of the blade-body cavity 72 on the trailing edge 51T side is closer to the trailing edge 51T than a position that is 70% of the width of the blade body 51 in the longitudinal direction Da from the leading edge 51L.

[0120] The resistance of the air flowing through the cavity 70 can be reduced.

[0121] The compressor 40 in the above embodiments and modified examples can be understood as follows, for example. (17) A compressor 40 in a seventeenth aspect includes a compressor rotor 41 rotatable about an axis Ar, a compressor casing 45 covering the compressor rotor 41, and a plurality of stator vane rows 48, 48a arranged in an axial direction Da in which the axis Ar extends. The compressor rotor 41 includes a rotor shaft 42 extending in the axial direction Da around the axis Ar, and a plurality of moving blade rows 43 attached to the rotor shaft 42 and arranged in the axial direction Da. Each of the plurality of stator vane rows 48, 48a is disposed on the axial downstream side Dad in the axial direction Da of any one of the plurality of moving blade rows 43, and attached to the compressor casing 45. Each of the plurality of stator vane rows 48, 48a has a plurality of stator vanes arranged in the circumferential direction Dc relative to the axis Ar. Of the plurality of stator vane rows 48, 48a, at least one stator vane row 48a has each of the plurality of stator vanes which are the compressor stator vanes 50a, 50b, 50c, 50d, 50e according to any one of the first to sixteenth aspects. The fore-and-aft direction Da is the axial direction Da. The blade height direction Dr is the radial direction Dr relative to the axis Ar. The blade height first side Dro is the radially outer side Dro of the radially inner side Dri and the radially outer side Dro in the radial direction Dr. The blade height second side Dri is the radially inner side Dri.

[0122] (18) An eighteenth aspect of the compressor 40 is the compressor 40 of the seventeenth aspect, wherein the compressor casing 45 is cylindrical about the axis Ar and includes one or more blade rings 47, 47 a that hold a portion of the plurality of stator vane rows 48, 48 a, and a casing body 46 that is disposed on the outer circumferential side of the one or more blade rings 47, 47 a and to which the one or more blade rings 47, 47 a are attached. Of the one or more blade rings 47, 47 a, the blade ring 47 a that holds at least one stator vane row 48 a has a blade ring bleed flow passage 47 e that penetrates from an inner circumferential side to an outer circumferential side and communicates with the cavity 70 of each of the plurality of stator vanes 50 a, 50 b, 50 c, 50 d, 50 e that the at least one stator vane row 48 a has, and into which air from the cavity 70 can flow. The casing body 46 has a body bleed air passage 46e that penetrates from the inner peripheral side to the outer peripheral side, into which air from the blade ring bleed air passage 47e flows and which can be exhausted to the outer peripheral side of the casing body 46.

[0123] The gas turbine facilities in the above embodiments and modified examples can be understood as follows, for example. (19) A gas turbine facility in a nineteenth aspect includes: a gas turbine 10 having the compressor 40 of the eighteenth aspect, a combustor 20 capable of generating combustion gas by burning fuel in air compressed by the compressor 40, and a turbine 30 capable of being driven by the combustion gas, and a cooling device 16. The turbine 30 has a turbine rotor 31 rotatable about the axis Ar, a turbine casing 35 covering the turbine rotor 31, and a plurality of stator vane rows 38 arranged in the axial direction Da and on the inner peripheral side of the turbine casing 35. The cooling device 16 includes an bleed line 17 a connected to the main bleed air flow path 46 e of the compressor casing 45, a cooler 18 capable of cooling the air from the bleed line 17 a, a boost compressor 19 capable of compressing the air cooled by the cooler 18, and a cooling air line 17 b capable of guiding the air cooled by the cooler and compressed by the boost compressor 19 to at least one of the plurality of stator blade rows 38 of the turbine 30.

[0124] In this embodiment, the air in the cavity 70 of the stator vanes 50a, 50b, 50c, 50d, and 50e is forcibly sucked in by the boost compressor 19 of the cooling device 16, so that some of the air flowing along the negative pressure surface 52n is more likely to flow into the cavity 70.

[0125] According to one aspect of the present disclosure, it is possible to suppress the development of a boundary layer formed along the suction surface of a compressor stator vane, thereby expanding the operating range of the compressor and improving the efficiency of the compressor.

[0126] 10: Gas turbine 11: Gas turbine rotor 14: Intermediate casing 15: Gas turbine casing 16: Cooling device 17a: Bleed line 17b: Cooling air line 18: Cooler 19: Boost compressor 20: Combustor 30: Turbine 31: Turbine rotor 32: Rotor shaft 33: Row of moving blades 35: Turbine casing 38: Row of stator blades 40: Compressor 41: Compressor rotor 42: Rotor shaft 43: Row of moving blades 45: Compressor casing 46: Casing body 46e: Main body bleed air passage 47, 47a: Blade ring 47e: Blade ring bleed air passage 47p: Gas path surface 47g: Blade groove 48, 48a: Row of stator blades 50, 50a, 50b, 50c, 50d, 50e: Stator blades (compressor stator blades) 51: Blade body 51L: leading edge 51T: trailing edge 52p: pressure surface 52n: suction surface 53: opening forming region 55: suction hole 55i: inlet opening 55o: outlet opening 61o: outer shroud (first shroud) 62o: outer gas path surface (first gas path surface, or simply gas path surface) 63o: outer counter-gas path surface (first counter-gas path surface) 64o: side circumferential surface (first side circumferential surface) 64f: front end surface 64b: rear end surface 64s: side end surface 65o: opening forming region 66: suction hole 66i: inlet opening 66o: outlet opening 61i: inner shroud (second shroud) 62i: inner gas path surface (second gas path surface, or simply gas path surface) 63i: inner counter-gas path surface (second counter-gas path surface) 64i: side circumferential surface (second side circumferential surface) 65i: opening formation region 70: cavity 71: outer cavity 71p: outer inner surface 72: blade body cavity 72p: suction side inner surface 73: inner cavity 73p: inner inner surface 76: corner surface A: air G: combustion gas F: fuel CaL: camber line ChL: chord line TL: tangent β: flow angle κ: blade angle θ: incidence angle RO: outer region (first side region) RM: middle region RI: inner region (second side region) Ar: axis Da: axial direction (front-rear direction) Dau: axial upstream side (leading edge side) Dad: axial downstream side (trailing edge side) Dc: circumferential direction Dcn: circumferential suction side Dcp: circumferential pressure side Dr: radial direction (blade height direction) Dro: radial outer side (blade height first side) Dri: radially inner side (second blade height side)

Claims

1. A blade body having an airfoil-shaped cross section and extending in a blade height direction including a directional component perpendicular to the cross section; a first shroud provided at the end of the blade body on the first blade height side of a first blade height side and a second blade height side in the blade height direction; and a second shroud provided at the end of the blade body on the second blade height side, wherein the blade body has a leading edge, a trailing edge, a pressure side connecting the leading edge and the trailing edge, and a suction side connecting the leading edge and the trailing edge and in a back-to-back relationship with the pressure side, and the first shroud has a first gas path surface facing the second blade height side and extending from the end of the blade body on the first blade height side in a direction including a directional component perpendicular to the blade height direction, a first counter-gas path surface facing the first blade height side and in a back-to-back relationship with the first gas path surface, and a first side peripheral surface connecting the edge of the first gas path surface and the edge of the first counter-gas path surface, the second shroud has a second gas path surface facing the first blade height side and extending from an end of the blade body on the second blade height side in a direction including a directional component perpendicular to the blade height direction, and a second counter-gas path surface facing the second blade height side and back-to-back with the second gas path surface; the blade body and the first shroud have cavities that are continuous within the blade body and the first shroud and open on the first counter-gas path surface or the first peripheral surface; the blade body has a plurality of suction holes that have inlet openings that open on the suction surface and outlet openings that open on an inner surface that defines the cavity, and that penetrate from the suction surface to the inner surface that defines the cavity; an area on the suction surface of a predetermined width in the fore-aft direction where the leading edge and the trailing edge are aligned and that extends from the end of the suction surface on the first blade height side to the end of the second blade height side forms an opening formation area; and the opening formation area has the inlet openings formed for each of the plurality of suction holes that are aligned in the blade height direction and the fore-aft direction. Compressor stator vanes.

2. A compressor stator vane according to claim 1, wherein the opening formation region has: a first side region including the end of the suction surface on the first blade height side; a middle region including a middle position in the blade height direction on the suction surface and extending from the end of the first side region on the second blade height side to the second blade height side; and a second side region extending from the end of the middle region on the second blade height side to the end of the suction surface on the second blade height side, and wherein the total area of ​​the inlet openings in at least one of the first side region and the second side region is larger than the total area of ​​the inlet openings in the middle region.

3. A compressor stator vane according to claim 2, wherein the number of the inlet openings in the at least one side region is greater than the number of the inlet openings in the intermediate region, and the density of the inlet openings in the at least one side region is greater than the density of the inlet openings in the intermediate region.

4. A compressor vane as claimed in claim 2, wherein the longitudinal width of said at least one side region gradually increases with increasing distance from said intermediate region in said blade height direction, the maximum longitudinal width of said at least one side region is wider than the maximum longitudinal width of said intermediate region, the number of said inlet openings in said at least one side region gradually increases with increasing distance from said intermediate region in said blade height direction and is greater than the number of said inlet openings in said intermediate region, and the density of said inlet openings in said at least one side region is higher than the density of said inlet openings in said intermediate region.

5. A compressor stator vane according to claim 2, wherein said at least one side region includes said first side region and said second side region.

6. A compressor stator vane according to claim 1, wherein the central position in the longitudinal direction of the opening formation region is within a range of 45% to 65% of the longitudinal width of the blade body from the leading edge.

7. A compressor stator vane according to claim 6, wherein the position of the end of the opening formation region on the side of the leading edge in the longitudinal direction is located on the side of the trailing edge from a position that is 30% of the width of the blade body in the longitudinal direction from the leading edge.

8. A compressor vane according to claim 1, wherein at least one of the first shroud and the second shroud has an inlet opening that opens in the gas path surface of the at least one shroud and an outlet opening that opens in the inner surface that defines the cavity, and a plurality of suction holes are formed that penetrate from the gas path surface to the inner surface that defines the cavity, the side on which the suction surface exists relative to the pressure surface is the suction side, a region on the gas path surface of the at least one shroud that is on the suction side with respect to the blade body and that is along the suction surface forms an opening formation region, and the inlet openings are formed in the opening formation region in the gas path surface of the at least one shroud for each of the plurality of suction holes formed in the at least one shroud.

9. A compressor vane according to claim 8, wherein an end of the opening forming region of the gas path surface of at least one of the shrouds on the side of the leading edge in the longitudinal direction is located on the side of the trailing edge of a position that is 30% of the width of the blade body in the longitudinal direction from the leading edge.

10. A compressor vane as claimed in claim 1, wherein each of the plurality of suction holes is inclined with respect to the plane on which the inlet opening is formed so as to gradually extend from the leading edge side to the trailing edge side in the fore-and-aft direction as it moves from the inlet opening to the outlet opening, the angle of the direction in which the plurality of suction holes extend with respect to the plane on which the inlet opening is formed being between 20° and 70°, and each of the plurality of suction holes has a minimum inner diameter in a portion between the inlet opening and the outlet opening, and gradually increases in diameter from the minimum inner diameter portion toward the inlet opening and also gradually increases in diameter from the minimum inner diameter portion toward the outlet opening.

11. A compressor vane according to claim 10, wherein the ratio of the hole length of each of the plurality of suction holes to the minimum inner diameter of each of the plurality of suction holes is 2 or less.

12. A compressor stator vane according to claim 10, wherein the ratio of the area of ​​the outlet opening to the cross-sectional area of ​​the suction hole at the position of minimum inner diameter is 1.5 or less, and the area of ​​the outlet opening is the area in a direction perpendicular to the direction in which the suction hole having the outlet opening extends.

13. A compressor vane according to claim 1, wherein the minimum inner diameter of each of the plurality of suction holes is 0.8% or more and 3.0% or less of the width of the blade body in the longitudinal direction.

14. A compressor stator vane according to claim 1, wherein the central axis distance between two adjacent suction holes among the plurality of suction holes is 1.5% or more and 7.0% or less of the width of the blade body in the longitudinal direction.

15. A compressor stator vane according to claim 1, wherein the inner surface defining the cavity has a plurality of partial inner surfaces connected to one another, and the surfaces of corners of two adjacent partial inner surfaces among the plurality of partial inner surfaces are curved surfaces with a radius of at least 3.5% of the width of the blade body in the longitudinal direction.

16. A compressor stator vane as claimed in claim 1, wherein the longitudinal width of the blade-body cavity, which is the portion of the cavity formed in the blade body, is 60% or more of the longitudinal width of the blade body, the position of the leading edge side end of the blade-body cavity is closer to the leading edge than a position that is 20% of the longitudinal width of the blade body from the leading edge, and the position of the trailing edge side end of the blade-body cavity is closer to the trailing edge than a position that is 70% of the longitudinal width of the blade body from the leading edge.

17. A compressor comprising: a compressor rotor rotatable about an axis; a compressor casing covering the compressor rotor; and a plurality of stator vane rows lined up in the axial direction along which the axis extends, wherein the compressor rotor has a rotor shaft extending in the axial direction about the axis, and a plurality of moving blade rows lined up in the axial direction and attached to the rotor shaft, wherein each of the plurality of stator vane rows is disposed downstream in the axial direction of any one of the plurality of moving blade rows and attached to the compressor casing, wherein each of the plurality of stator vane rows has a plurality of stator vanes lined up in the circumferential direction about the axis, and wherein each of the plurality of stator vane rows has a compressor stator vane as defined in any one of claims 1 to 16, wherein the fore-aft direction is the axial direction, and the blade height direction is a radial direction about the axis, the first blade height side is the radially outer side of a radially inner side and a radially outer side in the radial direction, and the second blade height side is the radially inner side.

18. A compressor as claimed in claim 17, wherein the compressor casing is cylindrical about the axis and comprises one or more blade rings that hold some of the plurality of stator vane rows, and a casing body that is arranged on the outer periphery of the one or more blade rings and to which the one or more blade rings are attached; wherein of the one or more blade rings, the blade ring that holds at least one stator vane row has a blade ring bleed flow passage that penetrates from the inner periphery to the outer periphery and communicates with the cavities of each of the plurality of stator vanes in the at least one stator vane row, and through which air from the cavities can flow in; and the casing body has a body bleed flow passage that penetrates from the inner periphery to the outer periphery, through which air from the blade ring bleed flow passage flows in and which can exhaust the air to the outer periphery of the casing body.

19. A gas turbine facility comprising: a compressor according to claim 18; a combustor capable of generating combustion gas by burning fuel in air compressed by the compressor; and a turbine capable of being driven by the combustion gas; and a cooling device, wherein the turbine has: a turbine rotor rotatable about the axis; a turbine casing covering the turbine rotor; and a plurality of stator blade rows arranged side by side in the axial direction and on the inner peripheral side of the turbine casing, and the cooling device has: an bleed air line connected to the main bleed air flow path of the compressor casing; a cooler capable of cooling air from the bleed air line; a boost compressor capable of compressing the air cooled by the cooler; and a cooling air line capable of guiding the air cooled by the cooler and compressed by the boost compressor to at least one of the plurality of stator blade rows of the turbine.

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