Turbine stator blade and gas turbine

Abstract

A turbine stator blade according to at least one embodiment of the present invention is provided with: a first partition wall and a second partition wall that partition the internal space of an airfoil section; and a plurality of through holes that penetrate through the blade wall constituting the airfoil section. The first partition wall extends from the blade wall on the pressure surface side of the airfoil section to the blade wall on the negative pressure surface side of the airfoil section, and is provided closest to the leading edge. The second partition wall extends from the blade wall on the leading edge side of the airfoil section to the first partition wall, and partitions the internal space into a pressure surface-side leading edge cavity and a negative pressure surface-side leading edge cavity. When viewed from the blade height direction of the airfoil section, within the intersection angle between the first imaginary straight line and the extension direction of the blade wall, the first imaginary straight line is an obtuse angle on the leading edge side and an acute angle on the trailing edge side with respect to the first imaginary straight line. The through-holes include a pressure surface-side through-hole that opens to the pressure surface-side leading edge cavity, and a negative pressure surface-side through-hole that opens to the negative pressure surface-side leading edge cavity.

Description

Technical Field

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

[0002] This application claims priority based on Japanese Patent Application No. 2022-149115 filed with the Japan Patent Office on September 20, 2022, and the contents of which are incorporated herein by reference. Background Art

[0003] As a turbine blade of a gas turbine, there is known a device configured to film-cool the blade wall with cooling air ejected from the internal space of the airfoil portion through film cooling holes which are through-holes in the blade wall (see, for example, Patent Document 1).

[0004] Previous technical literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2001-140602 Summary of the invention

[0007] Technical issues to be solved by the invention

[0008] In the blade wall on the leading edge side of the turbine stator blade, the pressure of the working fluid acting on the blade wall is greatly different between the pressure surface side and the negative pressure surface side. Therefore, for example, in the turbine stator blade described in Patent Document 1, if the cooling air in the same cavity on the leading edge side is ejected from the film cooling holes provided in the blade wall on the pressure surface side and the film cooling holes provided in the blade wall on the negative pressure surface side, the flow rate of the cooling air from the film cooling holes provided in the blade wall on the negative pressure surface side is excessive. As a result, the efficiency of the gas turbine may be reduced.

[0009] In view of the above circumstances, an object of at least one embodiment of the present invention is to optimize the amount of cooling air in a turbine stator blade.

[0010] Means for solving technical problems

[0011] (1) A turbine stator blade according to at least one embodiment of the present invention includes:

[0012] The first partition wall and the second partition wall separate the inner space of the airfoil portion; and

[0013] A plurality of through holes penetrate the blade wall constituting the airfoil portion,

[0014] The first partition wall is a partition wall extending from a connection position with the blade wall on the pressure surface side of the airfoil portion, i.e., a pressure surface side connection position, to a connection position with the blade wall on the negative pressure surface side of the airfoil portion, i.e., a negative pressure surface side connection position, and is arranged at a position closest to the leading edge of the airfoil portion.

[0015] The second partition wall extends from a connection position with the blade wall on the leading edge side of the airfoil portion, i.e., a leading edge side connection position, to a connection position with the first partition wall, i.e., a trailing edge side connection position, to separate the internal space into a pressure surface side leading edge cavity and a negative pressure surface side leading edge cavity.

[0016] When the airfoil portion is observed from the blade height direction, within the intersection angle between a first imaginary straight line passing through the pressure surface side connection position and the negative pressure surface side connection position and the extension direction of the blade wall at the negative pressure surface side connection position, the intersection angle of the leading edge side relative to the first imaginary straight line is an obtuse angle, and the intersection angle of the trailing edge side of the airfoil portion relative to the first imaginary straight line is an acute angle,

[0017] The through holes include a pressure surface side through hole opened to the pressure surface side leading edge cavity and a negative pressure surface side through hole opened to the negative pressure surface side leading edge cavity.

[0018] (2) A gas turbine according to at least one embodiment of the present invention includes a turbine stator blade having the structure of (1) above.

[0019] Effects of the Invention

[0020] According to at least one embodiment of the present invention, the amount of cooling air in a turbine blade can be optimized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram showing the overall structure of a gas turbine.

[0022] Figure 2 It is a cross-sectional view showing a gas flow path of a turbine.

[0023] Figure 3 This is a cross-sectional view showing a cross section perpendicular to the blade height direction in an airfoil portion of a first-stage turbine stator blade according to one embodiment.

[0024] Figure 4 yes Figure 3 The enlarged view of the A portion is a diagram for explaining the flow of cooling air.

[0025] Figure 5 yes Figure 3 The enlarged view of the A portion is a view for explaining the internal partition wall of the airfoil portion.

[0026] Figure 6 This is a diagram for explaining a partition wall inside an airfoil portion of a first-stage turbine stator blade according to another embodiment.

[0027] Figure 7This is a diagram for explaining a partition wall inside an airfoil portion of a first-stage turbine stator blade according to still another embodiment. DETAILED DESCRIPTION

[0028] Hereinafter, several embodiments of the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described as embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples.

[0029] For example, expressions such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric" or "coaxial" that indicate relative or absolute configuration not only indicate such configuration in a strict sense, but also indicate a state of relative displacement with a tolerance or an angle or distance that can achieve the same degree of functionality.

[0030] For example, expressions such as “same”, “equal” and “homogeneous” that indicate that things are in the same state not only indicate the same state in a strict sense, but also indicate a state in which there is a tolerance or a difference in the degree to which the same function can be obtained.

[0031] For example, expressions indicating shapes such as a quadrilateral or a cylinder not only indicate shapes such as a quadrilateral or a cylinder in a strict geometric sense, but also indicate shapes including concave-convex portions or chamfered portions as long as the same effect can be obtained.

[0032] On the other hand, the expression “equipped with,” “set up,” “have,” “include” or “have” a constituent element is not an exclusive expression that excludes the existence of other constituent elements.

[0033] Figure 1 This is a schematic diagram showing the overall structure of a gas turbine. Figure 2 It is a cross-sectional view showing a gas flow path of a turbine.

[0034] In this embodiment, if Figure 1 As shown, the gas turbine 10 is composed of a compressor 11, a combustor 12, and a turbine 13 arranged coaxially via a rotor 14, and a generator 15 is connected to one end of the rotor 14. In the following description, the direction in which the axis of the rotor 14 extends is referred to as an axial direction Da, and the direction perpendicular to the axis Ax of the rotor 14 is referred to as a radial direction Dr. In addition, the radial direction Dr is referred to as a blade height direction h.

[0035] In the compressor 11, the air AI sucked from the air inlet is compressed by passing through a plurality of stationary blades and moving blades, thereby generating high-temperature and high-pressure compressed air AC. The combustor 12 supplies a predetermined fuel FL to the compressed air AC and burns it, thereby generating high-temperature and high-pressure combustion gas FG. The turbine 13 drives the rotating rotor 14 by passing the high-temperature and high-pressure combustion gas FG generated in the combustor 12 as a working fluid through a plurality of stationary blades and moving blades, thereby driving the generator 15 connected to the rotor 14.

[0036] And, if Figure 2 As shown in FIG. 1 , in the turbine 13, the turbine stationary blades (stationary blades) 21 are configured such that the hub side (radial direction Dr inner side) of the airfoil 23 is fixed to the inner shroud 25, and the front end side (radial direction Dr outer side) is fixed to the outer shroud 27. The turbine moving blades (moving blades) 41 are configured such that the base end of the airfoil 43 is fixed to the platform 45. Furthermore, the outer shroud 27 and the split ring 51 arranged on the front end side of the moving blade 41 are supported by the casing (turbine casing) 30 via the heat insulating ring 53, and the inner shroud 25 is supported by the support ring 31. Therefore, the combustion gas flow path 32 through which the combustion gas FG passes is formed along the axial direction Da as a space surrounded by the inner shroud 25, the outer shroud 27, the platform 45, and the split ring 51.

[0037] Hereinafter, the turbine first-stage stationary blade 21A arranged on the most upstream side in the axial direction Da among the turbine stationary blades 21 arranged in multiple stages in the axial direction Da will be described in detail.

[0038] Figure 3 This is a cross-sectional view showing a cross section perpendicular to the blade height direction in the airfoil portion 23 of a first-stage turbine stator blade 21A according to one embodiment.

[0039] Figure 4 yes Figure 3 The enlarged view of the A portion is a diagram for explaining the flow of cooling air.

[0040] Figure 5 yes Figure 3 The enlarged view of the A portion of FIG. 2 is a view for explaining the internal partition wall of the airfoil portion 23 .

[0041] Figure 6 This is a diagram for explaining the internal partition wall of the airfoil portion 23 of the first-stage turbine stator blade 21A according to another embodiment, and is equivalent to Figure 3 FIG is an enlarged view of part A of FIG.

[0042] Figure 7 This is a diagram for explaining the internal partition wall of the airfoil portion 23 of the first-stage turbine stator blade 21A according to another embodiment, and is equivalent to Figure 3FIG is an enlarged view of part A of FIG.

[0043] In addition, Figure 3 In the figure, for the convenience of illustration, description of a through hole 63 described later and a cooling air hole 81 of an insert member 80 described later is omitted.

[0044] And, in Figures 3 to 7 In the figure, for the convenience of illustration, a part or all of the embedding component 80 is omitted.

[0045] exist Figures 3 to 7 The turbine first-stage stationary blade 21A according to the illustrated embodiments has an internal space 61 formed inside the airfoil portion 23. The turbine first-stage stationary blade 21A according to the illustrated embodiments includes: a first partition wall 71, a second partition wall 72, and a third partition wall 73 that partition the internal space 61; and a plurality of through holes 63 that penetrate the blade wall 23W that constitutes the airfoil portion 23.

[0046] (1st partition 71)

[0047] exist Figures 3 to 7 In the turbine stage 1 stator blade 21A involved in several embodiments shown in FIG. Figures 5 to 7 As shown, the first partition wall 71 is a partition wall extending from the connection position with the blade wall 23W on the pressure surface 23P side of the airfoil portion 23, i.e., the pressure surface side connection position Ppc, to the connection position with the blade wall 23W on the negative pressure surface 23S side of the airfoil portion 23, i.e., the negative pressure surface side connection position Psc, and is arranged at a position closest to the leading edge 23L of the airfoil portion 23.

[0048] In the turbine first-stage stationary blade 21A according to some embodiments, the first partition wall 71 has a pressure surface side end 71p connected to the blade wall 23W on the pressure surface 23P side and a suction surface side end 71s connected to the blade wall 23W on the suction surface 23S side.

[0049] exist Figure 3 , Figure 4 and Figure 5 In the turbine first-stage stationary blade 21A according to the illustrated embodiment, the first partition wall 71 is formed linearly along a first virtual straight line Lv1 passing through the pressure surface side connection position Ppc and the suction surface side connection position Psc when viewed in the blade height direction h.

[0050] exist Figure 6 In the turbine first-stage stator blade 21A according to another embodiment shown in FIG. 1 , the first partition wall 71 is bent at the connection position with the first partition wall 71 and the second partition wall 72, i.e., the trailing edge side connection position Ptc, when viewed from the blade height direction h. The trailing edge side connection position Ptc is located closer to the trailing edge 23T than the first imaginary straight line Lv1. Figure 6In a turbine first-stage stationary blade 21A according to another embodiment shown in the figure, the first partition wall 71 is curved so as to be convex toward the trailing edge 23T side.

[0051] exist Figure 7 In the turbine first-stage stator blade 21A according to another embodiment shown in the figure, the first partition wall 71 includes: a pressure surface side region 711 extending from the pressure surface side connection position Ppc to the trailing edge side connection position Ptc when viewed from the blade height direction h; and a negative pressure surface side region 712 extending from the connection position Pc connected to the second partition wall 72 at a position closer to the leading edge 23L side than the trailing edge side connection position Ptc to the negative pressure surface side connection position Psc when viewed from the blade height direction h. That is, in Figure 7 In a turbine first-stage stationary blade 21A according to another embodiment shown, the first partition walls 71 are formed in a staggered manner.

[0052] In the turbine first stage stationary blade 21A involved in several embodiments, as shown in FIG. Figures 5 to 7 As shown, when observed from the blade height direction h, within the intersection angle of the first imaginary straight line Lv1 and the extension direction Dws of the blade wall 23W at the connection position Psc on the negative pressure surface side, the intersection angle θ1 on the leading edge 23L side is an obtuse angle relative to the first imaginary straight line Lv1, and the intersection angle θ2 on the trailing edge 23T side is an acute angle relative to the first imaginary straight line Lv1.

[0053] In addition, in the present application, the extension direction Dws of the blade wall 23W is the extension direction of the tangent on the center line C of the thickness of the blade wall 23W when viewed from the blade height direction h. For example, when a straight line such as the first imaginary straight line Lv1 intersects the extension direction Dws, the extension direction of the extension direction Dws at the intersection position of the straight line and the extension direction Dws is the extension direction of the tangent to the center line C of the thickness of the blade wall 23W at the intersection position.

[0054] (2nd partition 72)

[0055] exist Figures 3 to 7 In the turbine stage 1 stationary blade 21A involved in several embodiments shown, the second partition wall 72 extends from the connection position with the blade wall 23W on the leading edge 23L side, i.e., the leading edge side connection position Plc, to the connection position with the first partition wall 71, i.e., the trailing edge side connection position Ptc, and separates the internal space 61 into the pressure surface side leading edge cavity 61LP and the negative pressure surface side leading edge cavity 61LS.

[0056] In addition, if Figures 5 to 7As shown, the imaginary straight line passing through the leading edge connection position Plc and the trailing edge connection position Ptc when viewed from the blade height direction h is set as the second imaginary straight line Lv2. The influence of the intersection angle θ3 (or intersection angle θ4) between the second imaginary straight line Lv2 and the extension direction Dws of the blade wall 23W at the leading edge connection position Plc on the cooling air volume in the turbine stator blade 21 will be described in detail later.

[0057] (3rd partition 73)

[0058] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A according to the several embodiments shown, the third partition wall 73 is a partition wall extending from the trailing edge side connection position Ptc toward the trailing edge 23T side and partitioning the internal space 61. In the internal space 61 partitioned by the third partition wall 73, the internal space 61 closer to the pressure surface 23P side than the third partition wall 73 is a pressure surface side cavity 611, and the internal space 61 closer to the negative pressure surface 23S side than the third partition wall 73 is a negative pressure surface side cavity 612.

[0059] In the turbine first-stage stationary blade 21A according to some embodiments, the provision of the third partition wall 73 contributes to an increase in the strength of the first partition wall 71 .

[0060] (Through hole 63)

[0061] exist Figures 3 to 7 In the turbine stage 1 stator blade 21A involved in several embodiments shown in FIG. Figures 4 to 7 As shown, the through-holes 63 include a pressure-surface-side through-hole 63P opening into the pressure-surface-side leading edge cavity 61LP, and a negative-pressure-surface-side through-hole 63S opening into the negative-pressure-surface-side leading edge cavity 61LS.

[0062] In the turbine first-stage stator blade 21A according to some embodiments, it is preferable that the pressure surface side through holes 63P are formed into through hole rows 63L arranged at intervals in the blade height direction h. The number of through hole rows 63L composed of the pressure surface side through holes 63P is preferably 2 or more. Figures 4 to 7 In the illustrated example, the number of through hole rows 63L is, for example, seven.

[0063] It is preferable that, among the plurality of through-hole rows 63L formed of the pressure-surface-side through-holes 63P, the through-hole row 63L on the side closest to the trailing edge 23T intersects the first virtual straight line Lv1 when viewed in the blade height direction h.

[0064] In the turbine first-stage stationary blade 21A according to some embodiments, the suction side through holes 63S preferably form through hole rows 63L arranged at intervals in the blade height direction h. The number of through hole rows 63L formed by the suction side through holes 63S is preferably two.

[0065] Thus, in the blade wall 23W on the suction surface 23S side, film cooling can be effectively performed on the entire region near the leading edge 23L with a relatively small amount of cooling air.

[0066] Due to the presence of the first partition wall 71 , the blade wall 23W in the vicinity of the suction surface side connection position Psc has a structure in which it is difficult to perform impingement cooling on the inner wall surface 23Ws of the blade wall 23W.

[0067] Therefore, in the turbine first-stage stationary blade 21A involved in some embodiments, among the two through-hole rows 63L composed of the negative pressure side through-holes 63S, the through-hole row 63L close to the trailing edge 23T side preferably intersects with the first imaginary straight line Lv1 when viewed from the blade height direction h.

[0068] Thus, the blade wall 23W near the suction surface side connection position Psc where impingement cooling is difficult can be convectively cooled by the cooling air passing through the plurality of through holes 63 constituting the through hole row 63L near the trailing edge 23T.

[0069] (Embedded component 80)

[0070] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A involved in the several embodiments shown, there is a cylindrical insert component 80 having a plurality of cooling air holes 81 provided on the circumferential surface. In the turbine first-stage stationary blade 21A involved in the several embodiments, the insert component 80 is inserted into at least the pressure surface side leading edge cavity 61LP, the negative pressure surface side leading edge cavity 61LS, the pressure surface side cavity 611, and the negative pressure surface side cavity 612.

[0071] The insert member 80 is formed along the inner peripheral surface of each of the cavities 61LP, 61LS, 611, 612 in accordance with the shape of each of the cavities 61LP, 61LS, 611, 612 when viewed from the blade height direction.

[0072] Through the plurality of cooling air holes 81 of the insert component 80 inserted into each of the cavities 61LP, 61LS, 611, and 612, the cooling air flows from the inside of the insert component 80 toward the outside. Figure 4 By ejecting cooling air as indicated by arrow a, it is possible to perform impact cooling on the blade walls 23W that define the cavities 61LP, 61LS, 611, and 612.

[0073] In each of the cavities 61LP, 61LS, 611, and 612, the cooling air after the inner wall surface of the blade wall 23W is impact-cooled is as follows: Figure 4 As shown by arrows b, the liquid is ejected from the plurality of through holes 63 to the outside of the airfoil portion 23 to perform film cooling on the outer surface of the airfoil portion 23 .

[0074] (Regarding Optimization of the Amount of Cooling Air in the Turbine Stationary Blades 21)

[0075] On the blade wall 23W on the leading edge 23L side of the turbine stator blade 21, the pressure of the combustion gas FG acting on the blade wall 23W is greatly different between the pressure surface 23P side and the negative pressure surface 23S side. Therefore, for example, if the cooling air in the same cavity on the leading edge side is ejected from the film cooling holes (through holes) provided in the blade wall on the pressure surface side and the film cooling holes (through holes) provided in the blade wall on the negative pressure surface side as in the conventional turbine stator blade, the flow rate of the cooling air from the film cooling holes (through holes) provided in the blade wall on the negative pressure surface side is excessive. As a result, the efficiency of the gas turbine 10 may be reduced.

[0076] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A involved in the several embodiments shown, the internal space 61 is divided into the pressure surface side leading edge cavity 61LP and the negative pressure surface side leading edge cavity 61LS by the second partition wall 72, and the turbine first-stage stationary blade 21A is provided with a pressure surface side through hole 63P opening to the pressure surface side leading edge cavity 61LP, and a negative pressure surface side through hole 63S opening to the negative pressure surface side leading edge cavity 61LS. As a result, the air volume of the cooling air ejected from the pressure surface side through hole 63P can be ensured, and the air volume of the cooling air ejected from the negative pressure surface side through hole 63S can be easily suppressed. Therefore, it is easy to make the cooling air volume in the turbine first-stage stationary blade 21A appropriate.

[0077] And, in Figures 3 to 7 In the turbine first-stage vane 21A according to the illustrated embodiments, the first partition wall 71 and the second partition wall 72 define the pressure surface side leading edge cavity 61LP and the suction surface side leading edge cavity 61LS.

[0078] The pressure of the combustion gas FG acting on the blade wall 23W on the negative pressure surface 23S side decreases relatively sharply as it moves from the leading edge 23L side toward the trailing edge 23T side. Therefore, when the negative pressure surface side connection position Psc is relatively far away from the leading edge 23L, for example, when a plurality of negative pressure surface side through holes 63S opening to the same negative pressure surface side leading edge cavity 61LS are provided separately along the extension direction of the blade wall 23W, the flow rate of the cooling air ejected from the negative pressure surface side through holes 63S provided at a position relatively close to the trailing edge 23T is likely to become excessive. Therefore, it is preferable to reduce the size of the negative pressure surface side leading edge cavity 61LS by bringing the negative pressure surface side connection position Psc closer to the leading edge 23L, so that the range of the negative pressure surface side through holes 63S opening to the same negative pressure surface side leading edge cavity 61LS becomes narrower toward the leading edge 23L side.

[0079] according to Figures 3 to 7In the turbine first-stage stator blade 21A according to the several embodiments shown, the intersection angles θ1 and θ2 between the first imaginary straight line Lv1 and the extension direction Dws of the blade wall 23W at the negative pressure surface side connection position Psc when viewed from the blade height direction h are set as described above, so that the negative pressure surface side connection position Psc approaches the leading edge 23L side and the size of the negative pressure surface side leading edge cavity 61LS becomes smaller. Therefore, the range in which the negative pressure surface side through hole 63S opening to the same negative pressure surface side leading edge cavity 61LS can be provided can be narrowed toward the leading edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be optimized.

[0080] exist Figures 3 to 7 In the gas turbine 10 including the first-stage turbine vanes 21A according to the illustrated embodiments, the amount of cooling air in the turbine vanes 21 can be optimized to improve the efficiency of the gas turbine 10 .

[0081] (Regarding Optimization of the Amount of Cooling Air in the Turbine Stationary Blades 21)

[0082] exist Figures 3 to 7 In the turbine stage 1 stator blade 21A involved in several embodiments shown in FIG. Figures 5 to 7 As shown, when viewed from the blade height direction h, the intersection angle θ3 (or intersection angle θ4) between the second virtual straight line Lv2 and the extension direction Dws of the blade wall 23W at the leading edge connection position Plc is preferably 80 degrees or more and 100 degrees or less. The reason for this is described below.

[0083] As described above, the insert member 80 is formed along the inner peripheral surfaces of the pressure side leading edge cavity 61LP and the suction side leading edge cavity 61LS according to the shapes of the pressure side leading edge cavity 61LP and the suction side leading edge cavity 61LS when viewed from the blade height direction h.

[0084] Therefore, on the wall surface defining the pressure surface side leading edge cavity 61LP, that is, the inner wall surface 23Ws of the blade wall 23W and the wall surface 72Ps on the pressure surface 23P side of the second partition wall 72 (refer to Figure 5 ), the smaller the angle θ5 formed by the two wall surfaces, the smaller the angle formed by the wall portion of the embedded component 80 along the inner wall surface 23Ws of the blade wall 23W and the wall portion of the embedded component 80 along the wall surface 72Ps on the pressure surface 23P side of the second partition wall 72. Therefore, it is difficult to position the cooling air hole 81 in the wall portion of the embedded component 80 along the inner wall surface 23Ws of the blade wall 23W close to the leading edge 23L, and it is difficult to perform impingement cooling on the area close to the leading edge 23L in the inner wall surface 23Ws of the blade wall 23W.

[0085] Furthermore, the curved portion R (reference number 234) from the wall portion of the insert component 80 along the inner wall surface 23Ws of the blade wall 23W to the wall portion of the insert component 80 along the wall surface 72Ps on the pressure surface 23P side of the second partition wall 72 is formed. Figure 4 ) has a certain curvature radius. Therefore, the smaller the angle θ5 is, the further away the position of the curved portion R is from the leading edge 23L. Therefore, it is difficult to position the cooling air hole 81 close to the leading edge 23L, and it is difficult to perform impact cooling on the area close to the leading edge 23L in the inner wall surface 23Ws of the blade wall 23W.

[0086] Therefore, it is preferable that the above-mentioned angle θ5 has a size greater than a certain level.

[0087] Similarly, on the wall surface defining the negative pressure surface side leading edge cavity 61LS, that is, the inner wall surface 23Ws of the blade wall 23W and the wall surface 72Ss on the negative pressure surface 23S side of the second partition wall 72 (refer to Figure 5 ), the smaller the angle θ6 formed by the two wall surfaces, the smaller the angle formed by the wall portion of the embedded component 80 along the inner wall surface 23Ws of the blade wall 23W and the wall portion of the embedded component 80 along the wall surface 72Ss on the negative pressure surface 23S side of the second partition wall 72. Therefore, it is difficult to position the cooling air hole 81 in the wall portion of the embedded component 80 along the inner wall surface 23Ws of the blade wall 23W close to the leading edge 23L, and it is difficult to perform impact cooling on the area close to the leading edge 23L in the inner wall surface 23Ws of the blade wall 23W.

[0088] Furthermore, the curved portion R from the wall portion of the embedded component 80 along the inner wall surface 23Ws of the blade wall 23W to the wall portion of the embedded component 80 along the wall surface 72Ss on the negative pressure surface 23S side of the second partition wall 72 has a certain degree of curvature radius. Therefore, the smaller the above-mentioned angle θ6 is, the farther the position of the curved portion R is from the leading edge 23L. Therefore, it is difficult to position the cooling air hole 81 close to the leading edge 23L, and it is difficult to perform impingement cooling on the area close to the leading edge 23L in the inner wall surface 23Ws of the blade wall 23W.

[0089] Therefore, it is preferable that the above-mentioned angle θ6 has a size larger than a certain level.

[0090] However, the angle θ5 and the angle θ6 are complementary to each other, that is, the sum of the angle θ5 and the angle θ6 is 180 degrees, so if one of the angles θ5 and θ6 is increased, the other will be decreased. Therefore, the angle θ5 and the angle θ6 are preferably of the same magnitude.

[0091] Here, as mentioned above, Figures 3 to 7In the turbine stage 1 stationary blade 21A involved in several embodiments shown, if the crossing angle θ3 (or crossing angle θ4) is set to, for example, greater than 80 degrees and less than 100 degrees, the above-mentioned angle θ5 and angle θ6 can be made to have the same magnitude, so that it is easy to perform impact cooling on the area close to the leading edge 23L within the inner wall surface 23Ws of the blade wall 23W.

[0092] (About the intersection angle θ7)

[0093] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A according to the illustrated embodiments, a virtual straight line passing through the pressure surface side connection position Ppc and the trailing edge side connection position Ptc is referred to as a third virtual straight line Lv3.

[0094] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A according to the several embodiments shown, when viewed from the blade height direction h, among the intersection angles of the second virtual straight line Lv2 and the third virtual straight line Lv3, an intersection angle θ7 (reference angle θ7) on the pressure surface 23P side with respect to the second virtual straight line Lv2 and on the leading edge 23L side with respect to the third virtual straight line Lv3 is Figure 5 ) is preferably above 80 degrees and below 100 degrees.

[0095] The first partition wall 71 can more effectively suppress deformation of the second partition wall 72, such as tilting in the thickness direction of the second partition wall 72, as the intersection angle θ7 approaches 90 degrees. Figures 3 to 7 The turbine first-stage stationary blade 21A according to the illustrated embodiments can easily suppress deformation of the second partition wall 72 such as tilting in the thickness direction of the second partition wall 72 .

[0096] (About the intersection angles θ8 and θ9)

[0097] exist Figures 3 to 7 In the turbine first-stage stationary blade 21A according to the several embodiments shown, when viewed from the blade height direction h, the trailing edge side connecting position Ptc and the end portion 73T on the trailing edge side of the third partition wall 73 (reference Figure 3 ) and the first imaginary straight line Lv1, the intersection angle θ8 (reference Figure 5 ) is preferably an acute angle, and the intersection angle θ9 with respect to the fourth imaginary straight line Lv4 on the negative pressure surface 23S side and with respect to the first imaginary straight line Lv1 on the trailing edge 23T side is preferably an obtuse angle.

[0098] Thus, the extending direction of the third partition wall 73 is along the camber line CL of the airfoil portion 23 (refer to Figure 3), it is easy to ensure the size of both the internal space 61 on the pressure surface 23P side (pressure surface side cavity 611) and the internal space 61 on the negative pressure surface 23S side (negative pressure surface side cavity 612) separated by the third partition wall 73.

[0099] (Regarding the Positional Relationship between the Fifth Virtual Straight Line Lv5 and the Through Hole 63)

[0100] exist Figures 3 to 7 In the turbine stage 1 stator blade 21A involved in several embodiments shown in FIG. Figures 5 to 7 As shown, when observed from the blade height direction h, on the inner wall surface 23Ws of the blade wall 23W on the negative pressure surface 23S side between the intersection P of the fifth imaginary straight line Lv5 extending in a direction orthogonal to the extension direction Dws of the blade wall 23W at the pressure surface side connection position Ppc and the blade wall 23W on the negative pressure surface 23S side and the negative pressure surface side connection position Psc, it is best that there is no opening 63i of the through hole 63.

[0101] As a result, the amount of cooling air used for film cooling of a region with a relatively small heat load can be reduced, and the amount of cooling air in the turbine vane 21 can be optimized.

[0102] (Influence of the Shape of the First Partition Wall 71)

[0103] Since the cooling air at a relatively high pressure is supplied to the inner space, a phenomenon occurs in which the blade wall on the pressure surface side and the blade wall on the suction surface side of the airfoil portion expand separately.

[0104] As mentioned above, in Figure 3 , Figure 4 and Figure 5 In the turbine first-stage stationary blade 21A according to the illustrated embodiment, the first partition wall 71 is formed linearly along a first virtual straight line Lv1 passing through the pressure surface side connection position Ppc and the suction surface side connection position Psc when viewed in the blade height direction h.

[0105] This suppresses the first partition wall 71 formed linearly along the first virtual straight line Lv1 from expanding so that the blade wall 23W on the pressure surface 23P side and the blade wall 23W on the suction surface 23S side are separated, thereby suppressing deformation of the airfoil portion 23.

[0106] exist Figure 6 In the turbine first-stage stationary blade 21A involved in another embodiment shown, the first partition wall 71 is bent at the connection position with the first partition wall 71 and the second partition wall 72, that is, the trailing edge side connection position Ptc when viewed from the blade height direction h, and the trailing edge side connection position Ptc is located closer to the trailing edge 23T side than the first imaginary straight line Lv1.

[0107] As a result, the negative pressure surface side connection position Psc is further approached to the front edge 23L side, and the size of the negative pressure surface side front edge cavity 61LS is further reduced. Therefore, the range in which the negative pressure surface side through hole 63S opening to the same negative pressure surface side front edge cavity 61LS can be provided can be further narrowed toward the front edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be further optimized.

[0108] exist Figure 7 In the turbine stage 1 stationary blade 21A involved in another embodiment shown, the first partition wall 71 includes: a pressure surface side area 711, which extends from the pressure surface side connection position Ppc to the trailing edge side connection position Ptc when viewed from the blade height direction h; and a negative pressure surface side area 712, which extends from a connection position Pc connected to the second partition wall 72 at a position closer to the leading edge 23L side than the trailing edge side connection position Ptc to the negative pressure surface side connection position Psc when viewed from the blade height direction h.

[0109] As a result, the negative pressure surface side connection position Psc is further approached to the front edge 23L side, and the size of the negative pressure surface side front edge cavity 61LS is further reduced. Therefore, the range in which the negative pressure surface side through hole 63S opening to the same negative pressure surface side front edge cavity 61LS can be provided can be further narrowed toward the front edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be further optimized.

[0110] The present invention is not limited to the above-described embodiments, and includes modified embodiments of the above-described embodiments or embodiments in which these embodiments are appropriately combined.

[0111] For example, in the above description, the structure of the turbine 1st stage stator blade 21A is described as the internal structure of the turbine stator blade 21, but the above-mentioned structure of the turbine 1st stage stator blade 21A can also be applied to turbine stator blades 21 other than the turbine 1st stage stator blade 21A.

[0112] The contents described in each of the above-mentioned embodiments can be understood, for example, as follows.

[0113] (1) A turbine vane 21 according to at least one embodiment of the present invention includes: a first partition wall 71 and a second partition wall 72 that partition an internal space 61 of an airfoil portion 23; and a plurality of through holes 63 that penetrate a blade wall 23W constituting the airfoil portion 23. The first partition wall 71 is a partition wall that extends from a pressure surface side connection position Ppc, which is a connection position with the blade wall 23W on the pressure surface 23P side of the airfoil portion 23, to a negative pressure surface side connection position Psc, which is a connection position with the blade wall 23W on the negative pressure surface 23S side of the airfoil portion 23, and is provided at a position closest to the leading edge 23L of the airfoil portion 23. The second partition wall 72 extends from a leading edge side connection position Plc, which is a connection position with the blade wall 23W on the leading edge 23L side of the airfoil portion 23, to a trailing edge side connection position Ptc, which is a connection position with the first partition wall 71, and partitions the internal space 61 into a pressure surface side leading edge cavity 61LP and a negative pressure surface side leading edge cavity 61LS. When viewed from the blade height direction h of the airfoil 23, within the intersection angle of the first imaginary straight line Lv1 passing through the pressure surface side connection position Ppc and the negative pressure surface side connection position Psc and the extension direction Dws of the blade wall 23W at the negative pressure surface side connection position Psc, the intersection angle θ1 on the leading edge 23L side relative to the first imaginary straight line Lv1 is an obtuse angle, and the intersection angle θ2 on the trailing edge 23T side of the airfoil 23 relative to the first imaginary straight line Lv1 is an acute angle. The through hole 63 includes a pressure surface side through hole 63P opening to the pressure surface side leading edge cavity 61LP, and a negative pressure surface side through hole 63S opening to the negative pressure surface side leading edge cavity 61LS.

[0114] According to the structure of (1) above, in the turbine stator blade 21, the internal space 61 is divided into the pressure surface side leading edge cavity 61LP and the negative pressure surface side leading edge cavity 61LS by the second partition wall 72, and the turbine stator blade 21 is provided with the pressure surface side through hole 63P opening to the pressure surface side leading edge cavity 61LP, and the negative pressure surface side through hole 63S opening to the negative pressure surface side leading edge cavity 61LS. Thus, the air volume of the cooling air ejected from the pressure surface side through hole 63P can be ensured, and the air volume of the cooling air ejected from the negative pressure surface side through hole 63S can be easily suppressed. Therefore, it is easy to make the cooling air volume in the turbine stator blade 21 appropriate.

[0115] According to the configuration of (1) above, the first partition wall 71 and the second partition wall 72 define the pressure surface side leading edge cavity 61LP and the suction surface side leading edge cavity 61LS.

[0116] According to the structure of (1) above, by setting the intersection angles θ1 and θ2 of the first imaginary straight line Lv1 when viewed from the blade height direction h and the extension direction Dws of the blade wall 23W at the negative pressure surface side connection position Psc as described above, the negative pressure surface side connection position Psc approaches the leading edge 23L side and the size of the negative pressure surface side leading edge cavity 61LS becomes smaller. Therefore, the range of the negative pressure surface side through hole 63S that can be opened to the same negative pressure surface side leading edge cavity 61LS can be narrowed toward the leading edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be optimized.

[0117] (2) In several embodiments, in the structure of (1) above, when observed from the blade height direction, the intersection angle θ3 (or intersection angle θ4) between the second imaginary straight line Lv2 passing through the leading edge side connection position Plc and the trailing edge side connection position Ptc and the extension direction Dws of the blade wall 23W at the leading edge side connection position Plc is preferably greater than 80 degrees and less than 100 degrees.

[0118] According to the structure of (2) above, the angle θ5 in the pressure side leading edge cavity 61LP and the angle θ6 in the suction side leading edge cavity 61LS can be made the same, so that the area close to the leading edge 23L can be easily impact-cooled within the inner wall surface 23Ws of the blade wall 23W.

[0119] (3) In several embodiments, in the structure of (1) or (2) above, when observed from the blade height direction h, within the intersection angle of the second imaginary straight line Lv2 passing through the leading edge side connection position Plc and the trailing edge side connection position Ptc and the third imaginary straight line Lv3 passing through the pressure surface side connection position Ppc and the trailing edge side connection position Ptc, the intersection angle θ7 relative to the second imaginary straight line Lv2 on the pressure surface 23P side and relative to the third imaginary straight line Lv3 on the leading edge 23L side is preferably greater than 80 degrees and less than 100 degrees.

[0120] According to the above-mentioned structure (3), deformation of the second partition wall 72 such as the second partition wall 72 collapsing in the thickness direction can be easily suppressed.

[0121] (4) In some embodiments, in any of the structures (1) to (3) above, a third partition wall 73 extending from the trailing edge side connection position Ptc toward the trailing edge 23T side and partitioning the internal space 61 may be provided.

[0122] The above-mentioned structure (4) contributes to increasing the strength of the first partition wall 71 .

[0123] (5) In some embodiments, in the structure of (4) above, when observed from the blade height direction h, within the intersection angle of the fourth imaginary straight line Lv4 connecting the trailing edge side connection position Ptc and the end 73T on the trailing edge 23T side of the third partition 73 and the first imaginary straight line Lv1, the intersection angle θ8 relative to the fourth imaginary straight line Lv4 on the pressure surface 23P side and relative to the first imaginary straight line Lv1 on the trailing edge 23T side is preferably an acute angle, and the intersection angle θ9 relative to the fourth imaginary straight line Lv4 on the negative pressure surface 23S side and relative to the first imaginary straight line Lv1 on the trailing edge 23T side is preferably an obtuse angle.

[0124] According to the structure of (5) above, the extension direction of the third partition wall 73 is along the arc line CL of the airfoil portion 23, so it is easy to ensure the size of both the internal space 61 on the pressure surface 23P side (pressure surface side cavity 611) and the internal space 61 on the negative pressure surface 23S side (negative pressure surface side cavity 612) separated by the third partition wall 73.

[0125] (6) In several embodiments, in any of the structures (1) to (5) above, when observed from the blade height direction h, on the inner wall surface 23Ws of the blade wall 23W on the negative pressure surface 23S side between the intersection P of the fifth imaginary straight line Lv5 extending in a direction orthogonal to the extension direction Dws of the blade wall 23W at the pressure surface side connection position Ppc and the blade wall 23W on the negative pressure surface 23S side and the negative pressure surface side connection position Psc, it is preferable that there is no opening 63i of the through hole 63.

[0126] According to the configuration of (6) above, the amount of cooling air used for film cooling of a region with a relatively small heat load can be reduced, and the amount of cooling air in the turbine vane 21 can be optimized.

[0127] (7) In some embodiments, in any of the structures in (1) to (6) above, the suction surface side leading edge cavity 61LS is preferably an internal space 61 surrounded by the first partition wall 71, the second partition wall 72, and the blade wall 23W on the suction surface 23S side. The suction surface side through holes 63S are preferably formed in through hole rows 63L arranged at intervals in the blade height direction h. The number of the through hole rows 63L is preferably two.

[0128] According to the configuration of (7) above, in the blade wall 23W on the suction surface 23S side, the entire region near the leading edge 23L can be film-cooled efficiently with a relatively small amount of cooling air.

[0129] (8) In some embodiments, in the configuration of (7), of the two through-hole rows 63L, the through-hole row 63L on the trailing edge 23T side preferably intersects the first virtual straight line Lv1 when viewed from the blade height direction h.

[0130] According to the configuration of (8) above, the blade wall 23W near the suction surface side connection position Psc which is difficult to be impact cooled can be convectively cooled by cooling air passing through the plurality of through holes 63 constituting the through hole row 63L near the trailing edge 23T.

[0131] (9) In some embodiments, in any of the structures (1) to (8) above, the first partition wall 71 is preferably formed in a straight line along the first virtual straight line Lv1 when viewed from the blade height direction h.

[0132] According to the configuration of (9), the first partition wall 71 formed linearly along the first imaginary straight line Lv1 is prevented from expanding in a manner that separates the blade wall 23W on the pressure surface 23P side from the blade wall 23W on the suction surface 23S side, thereby preventing deformation of the airfoil portion 23.

[0133] (10) In some embodiments, in any of the structures (1) to (8) above, the first partition wall 71 is preferably curved at the trailing edge side connection position Ptc when viewed from the blade height direction h. The trailing edge side connection position Ptc is preferably located closer to the trailing edge 23T than the first virtual straight line Lv1.

[0134] According to the structure of (10) above, the negative pressure surface side connection position Psc is further approached to the front edge 23L side and the size of the negative pressure surface side front edge cavity 61LS is further reduced. Therefore, the range of the negative pressure surface side through hole 63S that can be opened to the same negative pressure surface side front edge cavity 61LS can be further narrowed toward the front edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be further appropriated.

[0135] (11) In several embodiments, in any of the structures described in (1) to (8) above, the first partition wall 71 may include: a pressure surface side region 711, which, when viewed from the blade height direction h, extends from a pressure surface side connection position Ppc to a trailing edge side connection position Ptc; and a negative pressure surface side region 712, which, when viewed from the blade height direction h, extends from a connection position Pc connected to the second partition wall 72 at a position closer to the leading edge 23L side than the trailing edge side connection position Ptc to a negative pressure surface side connection position Psc.

[0136] According to the structure of (11) above, the negative pressure surface side connection position Psc is further approached to the front edge 23L side and the size of the negative pressure surface side front edge cavity 61LS is further reduced. Therefore, the range of the negative pressure surface side through hole 63S that can be opened to the same negative pressure surface side front edge cavity 61LS can be further narrowed toward the front edge 23L side, and the flow rate of the cooling air ejected from the negative pressure surface side through hole 63S can be further optimized.

[0137] (12) A gas turbine 10 according to at least one embodiment of the present invention includes a turbine stator blade 21 having any one of the structures (1) to (11) described above.

[0138] According to the configuration of (12) above, the amount of cooling air in the turbine vanes 21 can be optimized, thereby improving the efficiency of the gas turbine 10 .

[0139] Explanation of symbols

[0140] 10-gas turbine, 13-turbine, 21-turbine stator blade (stator blade), 21A-turbine first stage stator blade, 23-airfoil, 23L-leading edge, 23P-pressure surface, 23S-pressure surface, 23T-trailing edge, 23W-blade wall, 61-internal space, 61LP-leading edge cavity on the pressure surface side, 61LS-leading edge cavity on the pressure surface side, 63-through hole, 63L-through hole row, 63P-through hole on the pressure surface side, 63S-through hole on the pressure surface side, 71-first partition wall, 72-second partition wall.

Claims

1. A turbine stator blade, comprising: The first partition wall and the second partition wall separate the inner space of the airfoil portion; and A plurality of through holes penetrate the blade wall constituting the airfoil portion, The first partition wall is a partition wall extending from a connection position with the blade wall on the pressure surface side of the airfoil portion, i.e., a pressure surface side connection position, to a connection position with the blade wall on the negative pressure surface side of the airfoil portion, i.e., a negative pressure surface side connection position, and is arranged at a position closest to the leading edge of the airfoil portion. The second partition wall extends from a connection position with the blade wall on the leading edge side of the airfoil portion, i.e., a leading edge side connection position, to a connection position with the first partition wall, i.e., a trailing edge side connection position, to separate the internal space into a pressure surface side leading edge cavity and a negative pressure surface side leading edge cavity. When the airfoil portion is observed from the blade height direction, within the intersection angle between a first imaginary straight line passing through the pressure surface side connection position and the negative pressure surface side connection position and the extension direction of the blade wall at the negative pressure surface side connection position, the intersection angle of the leading edge side relative to the first imaginary straight line is an obtuse angle, and the intersection angle of the trailing edge side of the airfoil portion relative to the first imaginary straight line is an acute angle, The through holes include a pressure surface side through hole opening toward the pressure surface side front edge cavity, and a negative pressure surface side through hole opening toward the negative pressure surface side front edge cavity. When observed from the height direction of the blade, within the intersection angle of the second imaginary straight line passing through the leading edge side connection position and the trailing edge side connection position and the third imaginary straight line passing through the pressure surface side connection position and the trailing edge side connection position, the intersection angle relative to the second imaginary straight line on the pressure surface side and relative to the third imaginary straight line on the leading edge side is greater than 80 degrees and less than 100 degrees.

2. A turbine stator blade, comprising: The first partition wall and the second partition wall separate the inner space of the airfoil portion; and A plurality of through holes penetrate the blade wall constituting the airfoil portion, The first partition wall is a partition wall extending from a connection position with the blade wall on the pressure surface side of the airfoil portion, i.e., a pressure surface side connection position, to a connection position with the blade wall on the negative pressure surface side of the airfoil portion, i.e., a negative pressure surface side connection position, and is arranged at a position closest to the leading edge of the airfoil portion. The second partition wall extends from a connection position with the blade wall on the leading edge side of the airfoil portion, i.e., a leading edge side connection position, to a connection position with the first partition wall, i.e., a trailing edge side connection position, to separate the internal space into a pressure surface side leading edge cavity and a negative pressure surface side leading edge cavity. When the airfoil portion is observed from the blade height direction, within the intersection angle between a first imaginary straight line passing through the pressure surface side connection position and the negative pressure surface side connection position and the extension direction of the blade wall at the negative pressure surface side connection position, the intersection angle of the leading edge side relative to the first imaginary straight line is an obtuse angle, and the intersection angle of the trailing edge side of the airfoil portion relative to the first imaginary straight line is an acute angle, The through holes include a pressure surface side through hole opening toward the pressure surface side front edge cavity, and a negative pressure surface side through hole opening toward the negative pressure surface side front edge cavity. The turbine stator blade includes a third partition wall extending from the trailing edge side connection position toward the trailing edge side and partitioning the internal space.

3. The turbine stator blade according to claim 2, wherein: When viewed from the blade height direction, within the intersection angle between the fourth imaginary straight line connecting the trailing edge side connection position and the end portion of the trailing edge side of the third partition wall and the first imaginary straight line, the intersection angle with respect to the fourth imaginary straight line on the pressure surface side and with respect to the first imaginary straight line on the trailing edge side is an acute angle, and the intersection angle with respect to the fourth imaginary straight line on the negative pressure surface side and with respect to the first imaginary straight line on the trailing edge side is an obtuse angle.

4. A turbine stator blade, comprising: The first partition wall and the second partition wall separate the inner space of the airfoil portion; and A plurality of through holes penetrate the blade wall constituting the airfoil portion, The first partition wall is a partition wall extending from a connection position with the blade wall on the pressure surface side of the airfoil portion, i.e., a pressure surface side connection position, to a connection position with the blade wall on the negative pressure surface side of the airfoil portion, i.e., a negative pressure surface side connection position, and is arranged at a position closest to the leading edge of the airfoil portion. The second partition wall extends from a connection position with the blade wall on the leading edge side of the airfoil portion, i.e., a leading edge side connection position, to a connection position with the first partition wall, i.e., a trailing edge side connection position, to separate the internal space into a pressure surface side leading edge cavity and a negative pressure surface side leading edge cavity. When the airfoil portion is observed from the blade height direction, within the intersection angle between a first imaginary straight line passing through the pressure surface side connection position and the negative pressure surface side connection position and the extension direction of the blade wall at the negative pressure surface side connection position, the intersection angle of the leading edge side relative to the first imaginary straight line is an obtuse angle, and the intersection angle of the trailing edge side of the airfoil portion relative to the first imaginary straight line is an acute angle, The through holes include a pressure surface side through hole opening toward the pressure surface side front edge cavity, and a negative pressure surface side through hole opening toward the negative pressure surface side front edge cavity. The first partition wall is formed in a straight line along the first imaginary straight line when viewed from the blade height direction.

5. A turbine stator blade, comprising: The first partition wall and the second partition wall separate the inner space of the airfoil portion; and A plurality of through holes penetrate the blade wall constituting the airfoil portion, The first partition wall is a partition wall extending from a connection position with the blade wall on the pressure surface side of the airfoil portion, i.e., a pressure surface side connection position, to a connection position with the blade wall on the negative pressure surface side of the airfoil portion, i.e., a negative pressure surface side connection position, and is arranged at a position closest to the leading edge of the airfoil portion. The second partition wall extends from a connection position with the blade wall on the leading edge side of the airfoil portion, i.e., a leading edge side connection position, to a connection position with the first partition wall, i.e., a trailing edge side connection position, to separate the internal space into a pressure surface side leading edge cavity and a negative pressure surface side leading edge cavity. When the airfoil portion is observed from the blade height direction, within the intersection angle between a first imaginary straight line passing through the pressure surface side connection position and the negative pressure surface side connection position and the extension direction of the blade wall at the negative pressure surface side connection position, the intersection angle of the leading edge side relative to the first imaginary straight line is an obtuse angle, and the intersection angle of the trailing edge side of the airfoil portion relative to the first imaginary straight line is an acute angle, The through holes include a pressure surface side through hole opening toward the pressure surface side front edge cavity, and a negative pressure surface side through hole opening toward the negative pressure surface side front edge cavity. The first partition wall is bent at the connection position on the trailing edge side when viewed from the blade height direction. The trailing edge side connection position is located closer to the trailing edge side than the first virtual straight line.

6. The turbine stator blade according to any one of claims 1 to 5, wherein: When viewed from the blade height direction, an intersection angle between a second virtual straight line passing through the leading edge side connection position and the trailing edge side connection position and an extension direction of the blade wall at the leading edge side connection position is greater than or equal to 80 degrees and less than or equal to 100 degrees.

7. The turbine stator blade according to any one of claims 1 to 5, wherein: When observed from the blade height direction, there is no opening of the through hole on the inner wall surface of the blade wall on the negative pressure side between the intersection of the fifth imaginary straight line extending in a direction perpendicular to the extension direction of the blade wall at the connection position on the pressure side and the blade wall on the negative pressure side and the connection position on the negative pressure side.

8. The turbine stationary blade according to any one of claims 1 to 5, wherein: The front edge cavity on the negative pressure surface side is the internal space surrounded by the first partition wall, the second partition wall and the blade wall on the negative pressure surface side. The negative pressure surface side through holes are formed in a row of through holes arranged at intervals in the blade height direction. The number of the through hole rows is 2.

9. The turbine stator blade according to claim 8, wherein: Of the two through-hole rows, the through-hole row close to the trailing edge intersects the first imaginary straight line when viewed from the blade height direction.

10. The turbine stationary blade according to any one of claims 1 to 3, wherein: The first partition wall includes: a pressure surface side area, which, when viewed from the blade height direction, extends from the pressure surface side connection position to the trailing edge side connection position; and a negative pressure surface side area, which, when viewed from the blade height direction, extends from a connection position connected to the second partition wall at a position closer to the leading edge side than the trailing edge side connection position to the negative pressure surface side connection position.

11. A gas turbine comprising the turbine stator blade according to any one of claims 1 to 5.

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