Rotating blade and gas turbine equipped with same

Abstract

This rotor blade comprises: a blade body extending in a blade height direction that is a direction perpendicular to an airfoil cross-section; and a platform that is provided to an end at a hub side, from between a tip side and the hub side which are of the blade height direction of the blade body. The blade body comprises: an anterior edge and a posterior edge; a ventral surface and a dorsal surface linking the anterior edge and the posterior edge together; and a cooling passage extending in the blade height direction between the ventral surface and the dorsal surface. The distance between an inner peripheral surface in the cooling passage and the dorsal surface is a dorsal wall thickness. The distance between the inner peripheral surface and the ventral surface is a ventral wall thickness. The ratio of the ventral wall thickness to the dorsal wall thickness is the ventral / dorsal wall thickness ratio. A position at 5 to 15% of the distance from the platform to the tip-side end of the blade body is a hub-side position, a position at 25 to 35% is a middle position, and a position at 90 to 100% is a tip-side position. The ventral / dorsal wall thickness ratio at any position between the hub-side position and the middle position in the cooling passage is smaller than the ventral / dorsal wall thickness ratio at any position between the middle position and the tip-side position.

Description

[Technical field]

[0001] The present disclosure relates to a rotor blade and a gas turbine including the same. This application claims priority to Patent Application No. 2021-214019, filed in Japan on December 28, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] A gas turbine includes a compressor that compresses air, a combustor that burns fuel in the air compressed by the compressor to generate combustion gas, and a turbine that is driven by the combustion gas from the combustor. The turbine includes a rotor that rotates about an axis and a turbine casing that covers the rotor. The rotor has a rotor shaft and a plurality of rotor blades attached to the rotor shaft.

[0003] The rotor blades of a gas turbine are exposed to high-temperature combustion gases, and therefore are generally cooled by air or the like.

[0004] For example, the rotor blade described in the following Patent Document 1 has multiple cooling passages extending in the blade height direction formed inside the blade surface of the rotor blade. In the drawings of Patent Document 1, the wall thickness, which is the distance between the inner peripheral surface of each of the multiple cooling passages and the blade surface, is drawn to gradually increase from the tip side to the hub side of the blade body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2000-213304 A Summary of the Invention [Problem to be solved by the invention]

[0006] Gas turbine rotor blades are required to have durability.

[0007] In view of the above, an object of the present disclosure is to provide a rotor blade capable of improving durability, and a gas turbine including the same. [Means for solving the problem]

[0008] A blade as one aspect for achieving the above object comprises a blade body having an airfoil-shaped cross section and extending in a blade height direction having a directional component perpendicular to the cross section, and a platform provided at an end of the blade body on the hub side of a tip side in the blade height direction and a hub side opposite the tip side, the blade body having a leading edge and a trailing edge extending in the blade height direction and facing opposite sides, a pressure side surface and a suction side surface extending in the blade height direction connecting the leading edge and the trailing edge and facing opposite sides, and one or more cooling passages located between the pressure side surface and the suction side surface and extending in the blade height direction, a distance between an inner circumferential surface and the suction side surface in the one or more cooling passages is a suction side wall thickness, a distance between the platform and the side surface of the blade body is a pressure side wall thickness, a ratio of the pressure side wall thickness to the suction side wall thickness is a pressure / suction wall thickness ratio, a position of 5 to 15% of the blade height, which is a distance from the platform to the tip side end of the blade body, is a hub side position, a position of 25 to 35% of the blade height from the platform is an intermediate position, and a position of 90 to 100% of the blade height from the platform is a tip side position, and the pressure / suction wall thickness ratio at any position in the blade height direction of a hub side region between the hub side position and the intermediate position in any one of the one or more cooling passages is smaller than the pressure / suction wall thickness ratio at any position in the blade height direction of a tip side region between the intermediate position and the tip side position. the one or more cooling passages include four or more cooling passages aligned in a camber line direction in which a camber line of the blade body extends, at least a front cooling passage located closest to the leading edge among the four or more cooling passages is the one cooling passage, and the pressure side wall thickness of the front cooling passage is maximum at the intermediate position in the blade height direction.

[0010] Further, one embodiment of a gas turbine includes a rotor shaft having a plurality of the above-mentioned rotor blades, the rotor shaft being rotatable about an axis and having a plurality of the rotor blades provided on its outer periphery, and a gas turbine casing covering the plurality of rotor blades and the rotor shaft. Effect of the Invention

[0011] According to one aspect of the present invention, the durability of the rotor blade can be improved. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic cross-sectional view of a gas turbine according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a perspective view of a rotor blade according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram illustrating a blade according to an embodiment of the present disclosure as viewed from a suction side. [Figure 4] FIG. 2 is a diagram showing a cross section of a wing body according to an embodiment of the present disclosure taken along a plane perpendicular to the wing height direction. [Diagram 5] FIG. 2 is a diagram showing positions and regions at wing height of a wing body according to an embodiment of the present disclosure. [Figure 6] 4 is a graph showing a pressure side wall thickness, a suction side wall thickness, and a pressure / suction wall thickness ratio in a blade height direction in a first cooling passage according to an embodiment of the present disclosure. [Figure 7] 4 is a graph showing the pressure side wall thickness in the blade height direction in each cooling passage (first cooling passage to sixth cooling passage) according to the embodiment of the present disclosure. [Figure 8] 4 is a graph showing the suction side wall thickness in the blade height direction in each cooling passage (first cooling passage to sixth cooling passage) according to the embodiment of the present disclosure. [Figure 9] 4 is a graph showing the anti-wall / suction wall thickness ratio in the blade height direction in each cooling passage (first cooling passage to sixth cooling passage) according to the embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0014] [Gas turbine embodiment] An embodiment of a gas turbine will be described with reference to Fig. 1. As shown in Fig. 1, a gas turbine 100 includes a compressor 1, an intermediate casing 2, a combustor 3, and a turbine 4.

[0015] (Compressor) The compressor 1 is a device that compresses air introduced from the outside, raises the pressure to a predetermined level, and supplies the compressed air to the intermediate casing 2. The compressor 1 has a compressor rotor 10 that is rotatable about an axis Ar that extends horizontally, and a compressor casing 20 that covers the compressor rotor 10.

[0016] Here, the direction in which the axis Ar extends (left-right direction in FIG. 1) is referred to as the "axial direction Da," the circumferential direction with respect to this axis Ar is simply referred to as the "circumferential direction Dc," and the direction perpendicular to the axis Ar is referred to as the "radial direction Dr." Moreover, of both sides of the axial direction Da, one side (the left side in FIG. 1) is referred to as the "axial upstream side Dau," and the opposite side (the right side in FIG. 1) is referred to as the "axial downstream side Dad."

[0017] In addition, the side approaching the axis Ar in the radial direction Dr is referred to as the "radially inner side Dri," and the opposite side is referred to as the "radially outer side Dro." In addition, the air introduced into the compressor 1 and circulating inside the compressor 1 is simply referred to as "air A1," and the air compressed by the compressor 1 and then introduced into the intermediate casing 2 is referred to as "compressed air A2."

[0018] The compressor rotor 10 has a compressor rotor shaft 11 and a plurality of compressor rotor blade rows 12 that are provided on the outer circumferential surface of the compressor rotor shaft 11 and arranged at intervals in the axial direction Da.

[0019] The compressor rotor shaft 11 is a columnar rotating shaft extending in the axial direction Da and rotatable about an axis Ar. The compressor rotor blade rows 12 are each provided from the outer periphery of the compressor rotor shaft 11, and are integrated with the compressor rotor shaft 11. Each compressor rotor blade row 12 has a plurality of compressor rotor blades arranged at intervals in the circumferential direction Dc.

[0020] The compressor casing 20 forms an outer shell of the compressor 1 and covers the compressor rotor 10 from the outer periphery side. The compressor casing 20 has a compressor casing body 21 having a cylindrical shape centered on the axis Ar, an air inlet portion 23 that introduces air A1 into the compressor casing body 21, and a plurality of compressor stator vane rows 22 that are provided on the inner circumferential surface of the compressor casing body 21 and arranged at intervals in the axial direction Da.

[0021] The compressor casing body 21 is supported by a compressor support (not shown) fixed to, for example, the ground, a stand, etc. The compressor casing body 21 compresses air A1 introduced from an air inlet portion 23 inside to generate compressed air A2, and then supplies this compressed air A2 to the intermediate casing 2. The air inlet portion 23 is provided on the axial upstream side Dau of the compressor casing body 21.

[0022] Each of the multiple compressor stator vane rows 22 is integrated with the compressor casing main body 21. Each compressor stator vane row 22 has a plurality of compressor vanes arranged at intervals in the circumferential direction Dc. The compressor stator vane rows 22 and the compressor rotor blade rows 12 are arranged alternately in the axial direction Da. Compressed air A2 compressed in the compressor casing 20 is introduced into the intermediate casing 2.

[0023] (Intermediate casing) The intermediate casing 2 forms a space therein for guiding the compressed air A2 introduced from the compressor 1 to the combustor 3. The intermediate casing 2 is connected to a compressor casing 20 from an axial downstream side Dad.

[0024] (Combustor) The combustor 3 is a device that generates high-temperature and high-pressure combustion gas G by utilizing fuel F supplied from the outside and compressed air A2 introduced into the intermediate casing 2, and supplies this combustion gas G to the turbine 4. The combustor 3 is provided in the intermediate casing 2.

[0025] (Turbine) The turbine 4 is a device that is driven by the combustion gas G supplied from the combustor 3. The turbine 4 has a turbine rotor 40 that is rotatable about an axis line Ar, and a turbine casing 43 that covers the turbine rotor 40.

[0026] The turbine rotor 40 has a turbine rotor shaft 41 and a plurality of turbine rotor blade rows 42 that are provided on the outer circumferential surface of the turbine rotor shaft 41 and arranged at intervals in the axial direction Da. Hereinafter, the turbine rotor shaft 41 will be referred to simply as the "rotor shaft 41," and the turbine rotor blade row 42 will be referred to simply as the "rotor blade row 42."

[0027] The rotor shaft 41 is a cylindrical rotating shaft extending in the axial direction Da and rotatable around the axis Ar. The multiple rotor blade rows 42 are all provided from the outer periphery of the rotor shaft 41, and are integrated with the rotor shaft 41. Each rotor blade row 42 has multiple turbine rotor blades 50 (rotor blades) arranged at intervals in the circumferential direction Dc. Hereinafter, the turbine rotor blades 50 will be simply referred to as "rotor blades 50."

[0028] The turbine casing 43 forms an outer shell of the turbine 4 and covers the turbine rotor 40 from the outer periphery side. The turbine casing 43 has a turbine casing body 44 having a cylindrical shape centered on the axis Ar, and a plurality of turbine stator vane rows 45 provided on the inner circumferential surface of the turbine casing body 44 and arranged at intervals in the axial direction Da. Hereinafter, the turbine stator vane row 45 will be simply referred to as the "stator vane row 45."

[0029] The turbine casing body 44 is supported by a turbine support (not shown) fixed to, for example, the ground, a frame, or the like. The turbine casing body 44 allows the combustion gas G introduced from the combustor 3 to flow therethrough. The combustion gas G is introduced from the axial upstream side Dau of the turbine casing body 44. Each of the multiple stator blade rows 45 is integral with the turbine casing body 44.

[0030] Each stator blade row 45 has a plurality of turbine stator blades arranged at intervals in the circumferential direction Dc. Hereinafter, the turbine stator blades will be simply referred to as "stator blades." The stator blade rows 45 and the rotor blade rows 42 are arranged alternately in the axial direction Da. The combustion gas G that has completed its work inside the turbine casing body 44 is discharged from the turbine casing body 44 toward the axial downstream side Dad.

[0031] The annular space between the outer circumferential side of the rotor shaft 41 and the inner circumferential side of the turbine casing body 44, in which the stator blade rows 45 and the rotor blade rows 42 are alternately arranged in the axial direction Da, serves as a combustion gas flow path Cg through which the combustion gas G from the combustor 3 flows. This combustion gas flow path Cg is annular about the axis Ar and is long in the axial direction Da.

[0032] In this embodiment, a gas turbine casing 101 is formed by the compressor casing 20, the intermediate casing 2, and the turbine casing 43. The compressor rotor 10 and the turbine rotor 40 are located on the same axis Ar, and are connected to each other, for example, in the intermediate casing 2 to form a gas turbine rotor 102. For example, an output shaft 201 provided in a generator 200 is connected to an end portion on the axial upstream side Dau of the gas turbine rotor 102 (compressor rotor 10).

[0033] An outline of the operation of the gas turbine 100 having the above configuration will be described below. The compressor 1 compresses air A1 to generate compressed air A2. This compressed air A2 flows into the combustor 3 via the intermediate casing 2. Fuel F is supplied to the combustor 3 from the outside.

[0034] In the combustor 3, the fuel F is combusted in the compressed air A2 to generate high-temperature and high-pressure combustion gas G. This combustion gas G is sent from the combustor 3 into the turbine casing 43. The turbine rotor 40 is rotated by this combustion gas G. In accordance with the rotation of the turbine rotor 40, the output shaft 201 of the generator 200 connected to the gas turbine rotor 102 rotates. As a result, the generator 200 generates electricity.

[0035] [Embodiment of the rotor blade] An embodiment of the rotor blade 50 of the gas turbine 100 described above will be described with reference to Fig. 2 to Fig. 9. As shown in Fig. 2 and Fig. 3, the rotor blade 50 has a blade body 60, a platform 70, and a shaft mounting portion 90.

[0036] (wing body) The blade body 60 has an airfoil-shaped cross section and extends in a direction having a component perpendicular to the cross section. Hereinafter, this direction will be referred to as the "blade height direction Dwh." When the rotor blade 50 is fixed to the rotor shaft 41, the blade height direction Dwh coincides with the radial direction Dr. Hereinafter, the side of the rotor shaft 41 with respect to the blade body 60 in the blade height direction Dwh will be referred to as the "hub side Dwhs," and the opposite side will be referred to as the "tip side Dwht."

[0037] The blade body 60 has a leading edge 60a and a trailing edge 60b extending in the blade height direction Dwh and facing opposite sides, a ventral side surface 61 and a suction side surface 62 connecting the leading edge 60a and the trailing edge 60b and facing opposite sides, and four or more cooling passages 63 located between the ventral side surface 61 and the suction side surface 62 and extending in the blade height direction Dwh.

[0038] When the rotor blade 50 is fixed to the rotor shaft 41, the leading edge 60a becomes the axially most upstream edge Dau of the rotor blade 50. When the rotor blade 50 is fixed to the rotor shaft 41, the trailing edge 60b becomes the axially most downstream edge Dad of the rotor blade 50. The ventral side surface 61 is a concavely curved pressure surface. The suction side surface 62 is a convexly curved surface toward the side where the ventral side surface 61 is concave, and is a suction side surface facing the opposite side to the ventral side surface 61.

[0039] The four or more cooling passages 63 are aligned in the direction of a camber line Lca connecting the leading edge 60a and the trailing edge 60b. Hereinafter, this direction is referred to as the "camber line direction Dlc." The blade body 60 of this embodiment has six cooling passages 63. A more detailed configuration of the blade body 60 will be described later.

[0040] (Platform) The platform 70 is a base that supports the wing body 60. The platform 70 is provided at the end of the hub side Dwhs of the wing body 60. The platform 70 is a plate-like member that extends from the end of the hub side Dwhs of the wing body 60 in a direction having a component perpendicular to the wing height direction Dwh.

[0041] A gas path surface 71 that faces the tip side Dwht and comes into contact with the combustion gas G is formed on this platform 70. The gas path surface 71 is a surface that extends in a direction having a component perpendicular to the blade height direction Dwh.

[0042] Here, a connection portion with the gas path surface 71 in the ventral side surface 61 and a connection portion with the gas path surface 71 in the dorsal side surface 62 form a fillet portion 80. The ventral side surface 61 of the fillet portion 80 expands in a direction away from the dorsal side surface 62 as it approaches the gas path surface 71 in the blade height direction Dwh. The dorsal side surface 62 of the fillet portion 80 expands in a direction away from the ventral side surface 61 as it approaches the gas path surface 71 in the blade height direction Dwh.

[0043] (Shaft mounting part) The shaft mounting part 90 fixes the platform 70 to the rotor shaft 41. The shaft mounting part 90 has a shank 91 extending from the platform 70 to the opposite side of the blade body 60 in the blade height direction Dwh, and a blade root 92 extending from the shank 91 to the opposite side of the blade body 60 in the blade height direction Dwh. The cross section of the blade root 92 is a Christmas tree shape. The blade root 92 fits into a blade root groove (not shown) of the rotor shaft 41 (see FIG. 1).

[0044] Here, the rotor blade 50 has a rotor blade cooling passage 51 therein. A cooling fluid A3 is supplied to the rotor blade cooling passage 51 from the outside of the rotor blade 50. The rotor blade 50 is cooled by the cooling fluid A3 flowing inside the rotor blade cooling passage 51.

[0045] The cooling fluid A3 in this embodiment is a part of the compressed air A2 introduced from the compressor 1 into the intermediate casing 2. The compressed air A2 as the cooling fluid A3 is supplied into the rotor blade cooling passage 51 through a cooling fluid introduction passage (not shown) formed inside the rotor shaft 41.

[0046] The blade cooling passage 51 is composed of a plurality of the above-mentioned cooling passages 63 formed inside the blade body 60, a plurality of platform cooling passages 75 formed inside the platform 70, and a plurality of shaft mounting portion cooling passages 93 formed in the shaft mounting portion 90.

[0047] The cooling passage 63 will be described in detail later. The platform cooling passage 75 and the shaft attachment portion cooling passage 93 each extend in the blade height direction Dwh. One of the shaft attachment portion cooling passages 93 and at least one of the multiple platform cooling passages 75 are in communication with each other.

[0048] The shaft mounting portion cooling passage 93 has a fluid inlet 93a that opens toward the rotor shaft 41 on the hub side Dwhs. The fluid inlet 93a is connected to the cooling fluid introduction passage. The cooling fluid A3 that flows in from the cooling fluid introduction passage flows into the shaft mounting portion 90 through the fluid inlet 93a.

[0049] The cooling fluid A3 that has flowed through the shaft attachment portion cooling passage 93 flows into the platform cooling passage 75 of the platform 70. The cooling fluid A3 that has flowed through the platform cooling passage 75 flows into the cooling passage 63 and cools the blade body 60.

[0050] The above-described wing body 60 will now be described in more detail.

[0051] As shown in Figs. 3 and 4, of the six cooling passages 63 of the blade body 60, the front cooling passage 64 closest to the leading edge 60a is referred to as a first cooling passage 631. The cooling passage 63 adjacent to the trailing edge 60b side of the first cooling passage 631 is referred to as a second cooling passage 632. The cooling passage 63 adjacent to the trailing edge 60b side of the second cooling passage 632 is referred to as a third cooling passage 633. The cooling passage 63 adjacent to the trailing edge 60b side of the third cooling passage 633 is referred to as a fourth cooling passage 634. The cooling passage 63 adjacent to the trailing edge 60b side of the fourth cooling passage 634 is referred to as a fifth cooling passage 635. The cooling passage 63 adjacent to the trailing edge 60b side of the fifth cooling passage 635 is referred to as a sixth cooling passage 636. The sixth cooling passage 636 is the rear cooling passage 65 closest to the trailing edge 60b of the six cooling passages 63.

[0052] In this embodiment, among a plurality of combinations (five pairs) obtained by selecting two adjacent cooling passages 63 from six cooling passages 63 (first cooling passage 631 to sixth cooling passage 636) arranged in the camber line direction Dlc, at least one pair of cooling passages 63 communicate with each other. Note that in Figs. 3 and 4, the communication between adjacent cooling passages 63 is omitted.

[0053] Of the six cooling passages 63, the front cooling passage 64 and one or more cooling passages 63 connected to the front cooling passage 64 in the camber line direction Dlc form a front cooling passage group 63a. In addition, of the six cooling passages 63, the rear cooling passage 65 located closest to the trailing edge 60b and one or more cooling passages 63 connected to the rear cooling passage 65 in the camber line direction Dlc form a rear cooling passage group 63b.

[0054] In this embodiment, a front cooling passage group 63a is configured by the first cooling passage 631 and the second cooling passage 632 serving as the front cooling passage 64. A rear cooling passage group 63b is configured by the third cooling passage 633, the fourth cooling passage 634, the fifth cooling passage 635, and the sixth cooling passage 636 serving as the rear cooling passage 65.

[0055] Therefore, the front cooling passage group 63a and the rear cooling passage group 63b form a cooling passage 63 in the blade body 60. In this embodiment, the third cooling passage 633 and the fourth cooling passage 634 communicate with the platform cooling passage 75 at their ends on the hub side Dwhs in the blade height direction Dwh.

[0056] Here, the distance between the inner circumferential surface of each cooling passage 63 and the dorsal side surface 62 is referred to as the "dorsal wall thickness Wn," and the distance between the inner circumferential surface of each cooling passage 63 and the ventral side surface 61 is referred to as the "ventral wall thickness Wp." In this embodiment, the dorsal wall thickness Wn indicates the shortest distance between the inner circumferential surface of the cooling passage 63 and the dorsal side surface 62, and the ventral wall thickness Wp indicates the shortest distance between the inner circumferential surface of the cooling passage 63 and the ventral side surface 61.

[0057] As shown in FIG. 4, in this embodiment, the dorsal wall thickness Wn in the first cooling passage 631 is referred to as the "first dorsal wall thickness Wn1", and the ventral wall thickness Wp in the first cooling passage 631 is referred to as the "first ventral wall thickness Wp1". The dorsal wall thickness Wn in the second cooling passage 632 is referred to as the "second dorsal wall thickness Wn2", and the ventral wall thickness Wp in the second cooling passage 632 is referred to as the "second ventral wall thickness Wp2". The dorsal wall thickness Wn in the third cooling passage 633 is referred to as the "third dorsal wall thickness Wn3", and the ventral wall thickness Wp in the third cooling passage 633 is referred to as the "third ventral wall thickness Wp3". The dorsal wall thickness Wn in the fourth cooling passage 634 is referred to as the "fourth dorsal wall thickness Wn4", and the ventral wall thickness Wp in the fourth cooling passage 634 is referred to as the "fourth ventral wall thickness Wp4". The dorsal wall thickness Wn in the fifth cooling passage 635 is referred to as a "fifth dorsal wall thickness Wn5", and the ventral wall thickness Wp in the fifth cooling passage 635 is referred to as a "fifth ventral wall thickness Wp5". The dorsal wall thickness Wn in the sixth cooling passage 636 is referred to as a "sixth dorsal wall thickness Wn6", and the ventral wall thickness Wp in the sixth cooling passage 636 is referred to as a "sixth ventral wall thickness Wp6".

[0058] The ratio of the ventral wall thickness Wp to the dorsal wall thickness Wn is referred to as the "ventral / dorsal wall thickness ratio Rpn." The ventral / dorsal wall thickness ratio Rpn is calculated by dividing the ventral wall thickness Wp by the dorsal wall thickness Wn.

[0059] In this embodiment, the abdominal / dorsal wall thickness ratio Rpn (first abdominal wall thickness Wp1 / first dorsal wall thickness Wn1) in the first cooling passage 631 is referred to as the "first abdominal / dorsal wall thickness ratio Rpn1". The abdominal / dorsal wall thickness ratio Rpn (second abdominal wall thickness Wp2 / second dorsal wall thickness Wn2) in the second cooling passage 632 is referred to as the "second abdominal / dorsal wall thickness ratio Rpn2". The abdominal / dorsal wall thickness ratio Rpn (third abdominal wall thickness Wp3 / third dorsal wall thickness Wn3) in the third cooling passage 633 is referred to as the "third abdominal / dorsal wall thickness ratio Rpn3". The abdominal / dorsal wall thickness ratio Rpn (fourth abdominal wall thickness Wp4 / fourth dorsal wall thickness Wn4) in the fourth cooling passage 634 is referred to as the "fourth abdominal / dorsal wall thickness ratio Rpn4". The abdominal / dorsal wall thickness ratio Rpn (fifth abdominal wall thickness Wp5 / fifth dorsal wall thickness Wn5) in the fifth cooling passage 635 is referred to as the "fifth abdominal / dorsal wall thickness ratio Rpn5". The abdominal / dorsal wall thickness ratio Rpn (sixth abdominal wall thickness Wp6 / sixth dorsal wall thickness Wn6) in the sixth cooling passage 636 is referred to as the "sixth abdominal / dorsal wall thickness ratio Rpn6".

[0060] 5, the blade height from the position of the gas path surface 71 of the platform 70 to the position of the tip side tip Tip of the blade body 60 that is connected to this gas path surface 71 and extends in the blade height direction Dwh is defined as 100%. At this time, a position within a range of 5 to 15% of the blade height from the position of the gas path surface 71 is referred to as the "hub side position Ph", a position within a range of 25 to 35% of the blade height from the position of the gas path surface 71 is referred to as the "middle position Pm", and a position within a range of 90 to 100% of the blade height from the position of the gas path surface 71 is referred to as the "tip side position Pt".

[0061] Moreover, the region between the hub side position Ph and the intermediate position Pm that does not include the intermediate position Pm is referred to as the "hub side region Rh," and the region between the intermediate position Pm and the tip side position Pt that includes the intermediate position Pm is referred to as the "chip side region Rt." In this embodiment, the hub side position Ph is the 10% position, the intermediate position Pm is the 30% position, and the tip side position Pt is the 95% position. Therefore, in this embodiment, the hub side region Rh is a region that is 10% or more and less than 30%, and the tip side region Rt is a region that is 30% or more and 95% or less.

[0062] Hereinafter, the pressure side wall thickness Wp, the suction side wall thickness Wn, and the pressure / suction wall thickness ratio Rpn in each cooling passage 63 of the blade body 60 in the blade height direction Dwh will be described with reference to FIGS.

[0063] 5, in order to show the transition of the pressure side wall thickness Wp, the suction side wall thickness Wn, and the pressure / suction wall thickness ratio Rpn in each cooling passage 63 in the blade cross section when the blade body 60 is virtually cut in a direction perpendicular to the blade height direction Dwh, the distance between the position of the gas path surface 71 (0%) and the position of the tip side tip Tip (100%) is divided at equal intervals. In this embodiment, the distance between the position of the gas path surface 71 and the position of the tip side tip Tip is divided into 20 equal parts at 5% intervals.

[0064] In this embodiment, the position of the gas path surface 71, that is, the position (0%) of the end of the hub side Dwhs of the blade body 60, is referred to as the "reference position P0". A position of 5% from the reference position P0 is referred to as the "first position P1". A position of 10% from the reference position P0 is referred to as the "second position P2". A position of 15% from the reference position P0 is referred to as the "third position P3". A position of 20% from the reference position P0 is referred to as the "fourth position P4". A position of 25% from the reference position P0 is referred to as the "fifth position P5". A position of 30% from the reference position P0 is referred to as the "sixth position P6". A position of 35% from the reference position P0 is referred to as the "seventh position P7". A position of 40% from the reference position P0 is referred to as the "eighth position P8". A position of 45% from the reference position P0 is referred to as the "ninth position P9". Moreover, a position that is 50% from the reference position P0 is referred to as the "tenth position P10." Moreover, a position that is 55% from the reference position P0 is referred to as the "eleventh position P11." Moreover, a position that is 60% from the reference position P0 is referred to as the "twelfth position P12." Moreover, a position that is 65% from the reference position P0 is referred to as the "thirteenth position P13." Moreover, a position that is 70% from the reference position P0 is referred to as the "fourteenth position P14." Moreover, a position that is 75% from the reference position P0 is referred to as the "fifteenth position P15." Moreover, a position that is 80% from the reference position P0 is referred to as the "sixteenth position P16." Moreover, a position that is 85% from the reference position P0 is referred to as the "seventeenth position P17." Moreover, a position that is 90% from the reference position P0 is referred to as the "eighteenth position P18." Moreover, the position that is 95% from the reference position P0 is referred to as the “nineteenth position P19.” Moreover, the position that is 100% from the reference position P0, that is, the position of the tip side end Tip, is referred to as the “tip position P20.”

[0065] Therefore, in this embodiment, the second position P2 is the hub side position Ph, the sixth position P6 is the intermediate position Pm, and the nineteenth position P19 is the tip side position Pt.

[0066] In the following, the "reference thickness" indicated by the solid scale lines in each graph of the ventral wall thickness Wp and the posterior wall thickness Wn shown in the drawings indicates the same thickness (dimension). Also, the dimensions corresponding to the intervals between the scale lines in each graph of the ventral wall thickness Wp and the posterior wall thickness Wn shown in the drawings are the same in each graph.

[0067] As shown in Figures 6 and 7, the first abdominal side wall thickness Wp1 in the first cooling passage 631 increases from the tip side position Pt toward the middle position Pm, reaches a maximum at the middle position Pm, and decreases from the middle position Pm toward the hub side position Ph.

[0068] 6 and 8, the first suction side wall thickness Wn1 in the first cooling passage 631 increases monotonically from the tip side position Pt toward the hub side position Ph. The first pressure side wall thickness Wp1 at the intermediate position Pm in the first cooling passage 631 as the front cooling passage 64 is larger than any position in the first pressure side wall thickness Wp1 for the first cooling passage 631 in the blade height direction Dwh, excluding the intermediate position Pm.

[0069] As shown in FIG. 6, the first anti-wall / back wall thickness ratio Rpn1 in the tip side region Rt changes with the change in the blade height direction Dwh.

[0070] On the other hand, the first anti-wall / suction wall thickness ratio Rpn1 in the hub side region Rh decreases from the middle position Pm in the blade height direction Dwh toward the hub side Dwhs.

[0071] That is, the first pressure side wall thickness Wp1 at any position in the blade height direction Dwh of the hub side region Rh in the first cooling passage 631 is smaller than the first pressure side wall thickness Wp1 at any position in the blade height direction Dwh of the tip side region Rt. Also, the first pressure side wall thickness ratio Rpn1 at any position in the blade height direction Dwh of the hub side region Rh in the first cooling passage 631 is smaller than the first pressure side wall thickness ratio Rpn1 at any position in the blade height direction Dwh of the tip side region Rt.

[0072] Also, the average first anti-wall / back wall thickness ratio Rpn1 in the blade height direction Dwh in the hub side region Rh is smaller than the average first anti-wall / back wall thickness ratio Rpn1 in the blade height direction Dwh in the tip side region Rt. Furthermore, the ratio of the change in the first anti-wall / back wall thickness ratio Rpn1 to the change in the blade height direction Dwh in the hub side region Rh is larger than the ratio of the change in the first anti-wall / back wall thickness ratio Rpn1 to the change in the blade height direction Dwh in the tip side region Rt.

[0073] Here, the first anti-wall / suction wall thickness ratio Rpn1 at the second position P2 (hub side position Ph) is 74%, and the first anti-wall / suction wall thickness ratio Rpn1 at the third position P3 is 80%. Therefore, the blade body 60 includes a part of the hub side region Rh in the first cooling passage 631 and has a part where the first anti-wall / suction wall thickness ratio Rpn1 is less than 80%.

[0074] As shown in Figures 7 and 8, the ventral wall thicknesses Wp (second ventral wall thickness Wp2 to sixth ventral wall thickness Wp6) and the dorsal wall thicknesses Wn (second dorsal wall thickness Wn2 to sixth dorsal wall thickness Wn6) of the second cooling passage 632 to sixth cooling passage 636 all monotonically increase from the tip side position Pt to the hub side position Ph.

[0075] 9 shows a list of the pressure / suction wall thickness ratios Rpn in the blade height direction Dwh at each position (second position P2 to nineteenth position P19) of each cooling passage 63 (first cooling passage 631 to sixth cooling passage 636). Of the pressure / suction wall thickness ratios Rpn, portions (positions) showing pressure / suction wall thickness ratios Rpn of 100% or more are circled.

[0076] As shown in FIG. 9 , the portion of the anti-to-suction wall thickness ratio Rpn of each cooling passage 63 (first cooling passage 631 and second cooling passage 632) included in the front cooling passage group 63a and at each position (second position P2 to nineteenth position P19) in the blade height direction Dwh that is 100% or more is greater than the portion of the anti-to-suction wall thickness ratio Rpn of each cooling passage 63 (third cooling passage 633 to sixth cooling passage 636) included in the rear cooling passage group 63b and at each position in the blade height direction Dwh.

[0077] Here, as shown in Figures 7 and 8, the ventral side wall thickness Wp (first ventral side wall thickness Wp1, second ventral side wall thickness Wp2) and the suction side wall thickness Wn (first suction side wall thickness Wn1, second suction side wall thickness Wn2) at any position in the blade height direction Dwh in the hub side region Rh in the front cooling passage group 63a become smaller from the cooling passage 63 (second cooling passage 632) located closest to the trailing edge 60b toward the front cooling passage 64 (first cooling passage 631) among the cooling passages 63 aligned in the camber line direction Dlc in the front cooling passage group 63a.

[0078] In addition, the ventral wall thickness Wp (third ventral wall thickness Wp3 to sixth ventral wall thickness Wp6) and the suction wall thickness Wn (third suction wall thickness Wn3 to sixth suction wall thickness Wn6) at any position in the blade height direction Dwh in the hub side region Rh in the rear cooling passage group 63b become smaller from the cooling passage 63 (third cooling passage 633) located closest to the leading edge 60a toward the rear cooling passage 65 (sixth cooling passage 636) among the cooling passages 63 aligned in the camber line direction Dlc in the rear cooling passage group 63b.

[0079] (Action and effect) During operation of the gas turbine 100, the blade body 60 of the rotor blade 50 and the platform 70 connected to the blade body 60 are exposed to high-temperature, high-pressure combustion gas G. This combustion gas G causes thermal expansion of the blade body 60 and the platform 70. Since the blade body 60 is connected to the platform 70, free thermal expansion is restricted by the blade body 60. In other words, the thermal expansion of the platform 70 is restricted by the blade body 60.

[0080] Furthermore, of the ventral side surface 61 and the suction side surface 62 of the blade body 60 having an airfoil-shaped cross section, the suction side surface 62 is subjected to a higher thermal load due to the combustion gas G. For this reason, the suction side surface 62 thermally expands more than the ventral side surface 61, and the blade body 60 may deform so that the leading edge 60a and the trailing edge 60b approach each other in the axial direction Da.

[0081] Therefore, higher thermal stress occurs in the vicinity of the connection part of the platform 70 with the ventral side surface 61 of the wing body 60 than in the vicinity of the connection part with the suction side surface 62. As a result, there is a possibility that the platform 70 may be damaged. In particular, thermal stress is concentrated in the vicinity of the connection part of the platform 70 with the leading edge 60a of the ventral side surface 61 of the wing body 60, and there is a high probability that damage will occur in this part.

[0082] According to the configuration of the rotor blade 50 according to the above embodiment, in the first cooling passage 631, the first anti-wall / spine wall thickness ratio Rpn1 at any position in the blade height direction Dwh of the hub side region Rh is smaller than the first anti-wall / spine wall thickness ratio Rpn1 at any position in the blade height direction Dwh of the tip side region Rt.

[0083] This allows the rigidity of the ventral side 61 side of the wing body 60 to be lower than the rigidity of the suction side 62 side, so that the ventral side 61 side of the wing body 60 can be more relaxed in terms of the thermal expansion of the platform than the suction side 62 side. In particular, the rigidity of the leading edge 60a side on the ventral side 61 side of the wing body 60 can be lower than that on the suction side 62 side of the wing body 60. This allows the thermal stress occurring in the platform 70 near the connection portion with the ventral side 61 of the wing body 60 to be reduced, so that the durability of the bucket 50 can be improved.

[0084] Also, the average pressure / back wall thickness ratio Rpn in the hub side region Rh of the first cooling passage 631 is smaller than the average pressure / back wall thickness ratio Rpn in the tip side region Rt of the first cooling passage 631. This allows the rigidity of the pressure side surface 61 side of the blade body 60 to be reduced in a balanced manner. In particular, the rigidity of the leading edge 60a side on the pressure side surface 61 side of the blade body 60 can be reduced in a balanced manner.

[0085] Furthermore, the portion of the anti-to-suction wall thickness ratio Rpn of each cooling passage 63 of the front cooling passage group 63a and at each of the plurality of positions in the blade height direction Dwh that is 100% or more is greater than the portion of the anti-to-suction wall thickness ratio Rpn of each cooling passage 63 of the rear cooling passage group 63b that is 100% or more. This makes it possible to increase the rigidity of the blade body 60 on the leading edge 60a side relative to the rear cooling passage group 63b.

[0086] Further, the pressure-side wall thickness Wp at any position in the blade height direction Dwh of the hub-side region Rh in the front cooling passage group 63a becomes smaller from the cooling passage 63 located closest to the trailing edge 60b in the front cooling passage group 63a toward the front cooling passage 64. That is, the pressure-side wall thickness Wp in the first cooling passage 631 is smaller than the pressure-side wall thickness Wp in the second cooling passage 632. As a result, the rigidity of the blade body 60 at any position in the hub-side region Rh in the front cooling passage group 63a decreases from the cooling passage 63 located closest to the trailing edge 60b in the front cooling passage group 63a toward the front cooling passage 64.

[0087] Further, the pressure-side wall thickness Wp at any position in the blade height direction Dwh of the hub-side region Rh in the rear cooling passage group 63b decreases from the cooling passage 63 located closest to the leading edge 60a in the rear cooling passage group 63b toward the rear cooling passage 65. That is, the pressure-side wall thickness Wp decreases in the order of the third cooling passage 633, the fourth cooling passage 634, the fifth cooling passage 635, and the sixth cooling passage 636. As a result, the rigidity of the blade body 60 at any position in the hub-side region Rh in the rear cooling passage group 63b decreases from the cooling passage 63 located closest to the leading edge 60a in the rear cooling passage group 63b toward the rear cooling passage 65.

[0088] In addition, the pressure side wall thickness Wp at any position in the hub side region Rh of the first cooling passage 631 is smaller than the pressure side wall thickness Wp at any position in the tip side region Rt. As a result, the rigidity of the hub side region Rh on the pressure side 61 side of the blade body 60 is lower than the rigidity of the tip side region Rt on the pressure side 61 side of the blade body 60. That is, the pressure side 61 side of the blade body 60 can relax the constraint of the thermal expansion of the platform. Therefore, the thermal stress generated in the vicinity of the connection part of the platform 70 with the pressure side 61 of the blade body 60 can be reduced, and the durability of the blade 50 can be improved.

[0089] In each cooling passage 63 (the first cooling passage 631 to the sixth cooling passage 636), the suction side wall thickness Wn at each of the plurality of positions in the blade height direction Dwh is smallest at the tip side position Pt, and largest at the hub side position Ph. This allows the hub side position Ph of the blade body 60 to support the centrifugal load applied to the blade body 60 at the tip side Dwht of the hub side position Ph.

[0090] In addition, the back wall thickness Wn in each cooling passage 63 (first cooling passage 631 to sixth cooling passage 636) gradually increases from the tip side position Pt to the hub side position Ph, so that each position on the blade body 60 can better support the centrifugal load applied to the blade body 60 on the tip side Dwht than at that position.

[0091] [Other embodiments] Although the embodiments of the present disclosure have been described above in detail with reference to the drawings, the specific configuration is not limited to the configuration of the embodiment, and addition, omission, substitution, and other modifications of the configuration are possible within the scope of the gist of the present disclosure. Furthermore, the present disclosure is not limited to the embodiments, but is limited only by the scope of the claims.

[0092] In the above embodiment, the first ventral wall thickness Wp1 in the first cooling passage 631 increases from the tip side position Pt toward the intermediate position Pm, reaches a maximum at the intermediate position Pm, and decreases from the intermediate position Pm toward the hub side position Ph, but this is not limited to the first cooling passage 631.

[0093] The abdominal wall thickness Wp in all or at least one of the cooling passages 63, namely the second cooling passage 632, the third cooling passage 633, the fourth cooling passage 634, the fifth cooling passage 635, and the sixth cooling passage 636, may increase from the tip side position Pt toward the intermediate position Pm, be maximum at the intermediate position Pm, and decrease from the intermediate position Pm toward the hub side position Ph.

[0094] Therefore, in the cooling passage 63, the abdominal / back wall thickness ratio Rpn at any position in the hub side region Rh is smaller than the abdominal / back wall thickness ratio Rpn at any position in the tip side region Rt. Also, the average abdominal / back wall thickness ratio Rpn in the hub side region Rh is smaller than the average abdominal / back wall thickness ratio Rpn in the tip side region Rt. Also, regardless of the positions, the ratio of the change in the abdominal / back wall thickness ratio Rpn to the change in the blade height direction Dwh in the hub side region Rh is larger than the ratio of the change in the abdominal / back wall thickness ratio Rpn to the change in the blade height direction Dwh in the tip side region Rt.

[0095] Furthermore, among the pressure side wall thicknesses Wp for one or more cooling passages 63 and for a plurality of positions in the blade height direction Dwh, the pressure side wall thickness Wp at the hub side position Ph in one cooling passage 63 may be the smallest.

[0096] In the embodiment, the first ventral wall thickness Wp1 is maximum at the middle position Pm. In other words, the position where the first ventral wall thickness Wp1 is maximum in the wing height direction Dwh is the middle position Pm. The position where the first ventral wall thickness Wp1 is maximum in the wing height direction Dwh, that is, the middle position Pm, is not limited to a position 30% of the wing height from the platform 70 as in the present embodiment, but may be a position 25 to 35% of the wing height from the platform 70.

[0097] [Note] The rotor blade described in the above embodiment and the gas turbine including the rotor blade can be understood as follows, for example.

[0098] (1) In the first embodiment, the rotor blade 50 has a wing body 60 having an airfoil-shaped cross section and extending in a wing height direction Dwh having a directional component perpendicular to the cross section, and the wing body 60 has a tip side Dwht in the wing height direction Dwh and a hub side Dwhs opposite to the tip side Dwht. The wing body 60 has a platform 70 provided at an end of the hub side Dwhs. The wing body 60 has leading edges 6 extending in the wing height direction Dwh and facing opposite sides. a ventral side surface 61 and a suction side surface 62 extending in the blade height direction Dwh to connect the leading edge 60a and the trailing edge 60b and facing opposite sides to each other; and one or more cooling passages 63 located between the ventral side surface 61 and the suction side surface 62 and extending in the blade height direction Dwh, a distance between an inner peripheral surface of the one or more cooling passages 63 and the suction side surface 62 is a suction side wall thickness Wn, The distance between the ventral side surface 61 and the tip side wall thickness Wp is the ventral wall thickness Wp, and the ratio of the ventral wall thickness Wp to the tip side wall thickness Wn is the ventral / suction wall thickness ratio Rpn. The hub side position Ph is a position of 5 to 15% of the blade height, which is the distance from the platform 70 to the end of the tip side Dwht in the blade body 60, the intermediate position Pm is a position of 25 to 35% of the blade height from the platform 70, and the tip side position Pt is a position of 90 to 100% of the blade height from the platform 70. In any one of the one or more cooling passages 63, the ventral / suction wall thickness ratio Rpn at any position in the blade height direction Dwh of the hub side region Rh between the hub side position Ph and the intermediate position Pm is smaller than the ventral / suction wall thickness ratio Rpn at any position in the blade height direction Dwh of the tip side region Rt between the intermediate position Pm and the tip side position Pt.

[0099] This allows the rigidity of the ventral surface 61 side of the wing body 60 to be reduced below the rigidity of the suction surface 62 side, thereby preventing the ventral surface 61 side of the wing body 60 from restricting the platform more than the suction surface 62 side.

[0100] (2) The rotor blade 50 in a second aspect is the rotor blade 50 of (1), wherein the average abdominal / spine wall thickness ratio Rpn in the hub side region Rh may be smaller than the average abdominal / spine wall thickness ratio Rpn in the tip side region Rt.

[0101] This allows the rigidity of the ventral surface 61 side of the wing body 60 to be reduced in a well-balanced manner.

[0102] (3) The rotor blade 50 in a third aspect is the rotor blade 50 of (1) or (2), wherein a ratio of a change in the pressure-to-suction wall thickness ratio Rpn to a change in the blade height direction Dwh in the hub side region Rh may be greater than a ratio of a change in the pressure-to-suction wall thickness ratio Rpn to a change in the blade height direction Dwh in the tip side region Rt.

[0103] (4) The rotor blade 50 in a fourth aspect is a rotor blade 50 according to any one of (1) to (3), wherein the one or more cooling passages 63 have four or more cooling passages 63 aligned in a camber line direction Dlc in which the camber line Lca of the blade body 60 extends, and at least one of the four or more cooling passages 63, a front cooling passage 64 located closest to the leading edge 60a, may be the one cooling passage 63.

[0104] This makes it possible to reduce thermal stress occurring in the vicinity of the joint portion between the platform 70 and the pressure side surface 61 side of the wing body 60 and the leading edge 60a side.

[0105] (5) The rotor blade 50 in a fifth aspect is the rotor blade 50 of (4), wherein the pressure side wall thickness Wp at the intermediate position Pm in the front cooling passage 64 may be greater than any position except for the intermediate position Pm in the blade height direction Dwh where the pressure side wall thickness Wp for the front cooling passage 64 is greatest.

[0106] (6) The rotor blade 50 in a sixth aspect is the rotor blade 50 of (4) or (5), and may have a portion including a part of the hub side region Rh in the one cooling passage 63, and the abdominal / spine wall thickness ratio Rpn is less than 80%.

[0107] (7) The rotor blade 50 in a seventh aspect is the rotor blade 50 of any one of (4) to (6), wherein, of the four or more cooling passages 63, the front cooling passage 64 and the one or more cooling passages 63 connected to the front cooling passage 64 form a front cooling passage group 63a, and, of the four or more cooling passages 63, a rear cooling passage 65 located closest to the trailing edge 60b and the one or more cooling passages 63 connected to the rear cooling passage 65 form a rear cooling passage group 63b, and a portion of 100% or more of the pressure-to-suction wall thickness ratios Rpn for each of the plurality of cooling passages 63 included in the front cooling passage group 63a and for each of the plurality of positions in the blade height direction Dwh may be greater than a portion of 100% or more of the pressure-to-suction wall thickness ratios Rpn for each of the one or more cooling passages 63 included in the rear cooling passage group 63b and for each of the plurality of positions in the blade height direction Dwh.

[0108] This makes it possible to increase the rigidity of the blade body 60 on the leading edge 60a side relative to the rear cooling passage group 63b.

[0109] (8) The rotor blade 50 in an eighth aspect is the rotor blade 50 of any one of (4) to (6), wherein, among the four or more cooling passages 63, the front cooling passage 64 and one or more of the cooling passages 63 connected to the front cooling passage 64 form a front cooling passage group 63a, and the pressure side wall thickness Wp at any position in the blade height direction Dwh of the hub side region Rh in the front cooling passage group 63a may become smaller toward the front cooling passage 64.

[0110] As a result, the rigidity of the blade body 60 at any position in the blade height direction Dwh in the hub side region Rh in the front cooling passage group 63a decreases from the cooling passage 63 located closest to the trailing edge 60b in the front cooling passage group 63a toward the front cooling passage 64.

[0111] (9) The rotor blade 50 in a ninth aspect is the rotor blade 50 of (8), wherein, among the four or more cooling passages 63, a rear cooling passage 65 located closest to the trailing edge 60b and one or more of the cooling passages 63 connected to the rear cooling passage 65 form a rear cooling passage group 63b, and the pressure side wall thickness Wp at any position in the blade height direction Dwh of the hub side region Rh in the rear cooling passage group 63b may decrease toward the rear cooling passage 65.

[0112] As a result, the rigidity of the blade body 60 at any position in the blade height direction Dwh in the hub side region Rh in the rear cooling passage group 63b decreases from the cooling passage 63 located closest to the leading edge 60a in the rear cooling passage group 63b toward the rear cooling passage 65.

[0113] (10) In a tenth aspect, the rotor blade 50 includes a blade body 60 having an airfoil-shaped cross section and extending in a blade height direction Dwh having a directional component perpendicular to the cross section, and a platform 70 provided at an end of the hub side Dwhs of the blade body 60, the tip side Dwht in the blade height direction Dwh and the hub side Dwhs opposite the tip side Dwht. The blade body 60 extends in the blade height direction Dwh and has a a leading edge 60a and a trailing edge 60b facing opposite sides, a ventral side surface 61 and a suction side surface 62 extending in the blade height direction Dwh to connect the leading edge 60a and the trailing edge 60b and facing opposite sides, and one or more cooling passages 63 located between the ventral side surface 61 and the suction side surface 62 and extending in the blade height direction Dwh, and a distance between an inner peripheral surface of the one or more cooling passages 63 and the suction side surface 62 is a suction side wall thickness Wn. The distance between the inner circumferential surface and the ventral side surface 61 in the one or more cooling passages 63 is a ventral side wall thickness Wp, a position of 5 to 15% of the blade height, which is the distance from the platform 70 to the end of the tip side Dwht in the blade body 60, is a hub side position Ph, a position of 25 to 35% of the blade height from the platform 70 is an intermediate position Pm, and a position of 90 to 100% of the blade height from the platform 70 is a tip side position Pt, and the ventral side wall thickness Wp at any position in the blade height direction Dwh of the hub side region Rh between the hub side position Ph and the intermediate position Pm in any one cooling passage 63 among the one or more cooling passages 63 is smaller than the ventral side wall thickness Wp at any position in the blade height direction Dwh of the tip side region Rt between the intermediate position Pm and the tip side position Pt.

[0114] As a result, the rigidity of the hub side region Rh on the ventral surface 61 side of the wing body 60 is lower than the rigidity of the tip side region Rt on the ventral surface 61 side of the wing body 60, thereby relaxing the restriction of thermal elongation of the platform 70 by the ventral surface 61 side of the wing body 60.

[0115] (11) In an eleventh aspect, the rotor blade 50 is any one of the rotor blades 50 of (1) to (10), and in the one cooling passage 63, among the suction side wall thicknesses Wn for each of a plurality of positions in the blade height direction Dwh, the suction side wall thickness Wn at the tip side position Pt may be smallest and the suction side wall thickness Wn at the hub side position Ph may be largest.

[0116] This allows the hub side position Ph of the blade body 60 to support the centrifugal load acting on the blade body 60 on the tip side Dwht of the hub side position Ph.

[0117] (12) The rotor blade 50 in a twelfth aspect is the rotor blade 50 of (11), wherein the suction side wall thickness Wn in the one cooling passage 63 may gradually increase from the tip side position Pt toward the hub side position Ph.

[0118] This allows each position on the blade body 60 to better support the centrifugal load acting on the blade body 60 on the tip side Dwht than that position.

[0119] (13) A gas turbine 100 in a thirteenth aspect includes a plurality of rotor blades 50 of any one of (1) to (12), a rotor shaft 41 rotatable about an axis Ar and having a plurality of the rotor blades 50 provided on its outer periphery, and a gas turbine casing 101 covering the plurality of rotor blades 50 and the rotor shaft 41. [Industrial Applicability]

[0120] According to the present disclosure, the durability of the rotor blade can be increased. [Explanation of symbols]

[0121] 1... compressor 2... intermediate casing 3... combustor 4... turbine 10... compressor rotor 11... compressor rotor shaft 12... compressor rotor blade row 20... compressor casing 21... compressor casing body 22... compressor stator blade row 23... air inlet section 40... turbine rotor 41... rotor shaft 42... rotor blade row 43... turbine casing 44... turbine casing body 45... stator blade row 50... rotor blade 51... rotor blade cooling passage 60... blade body 60a... leading edge 60b... trailing edge 61... ventral side 62... suction side 63... cooling passage 63a... front cooling passage group 63b... rear cooling passage group 64... front cooling passage 65... rear cooling passage 70... platform 71... gas path surface 75... platform cooling passage 80... fillet portion 90... shaft mounting portion 91... shank 92...Blade root 93...Shaft mounting portion cooling passage 93a...Fluid inlet 100...Gas turbine 101...Gas turbine casing 102...Gas turbine rotor 200...Generator 201...Output shaft 631...First cooling passage 632...Second cooling passage 633...Third cooling passage 634...Fourth cooling passage 635...Fifth cooling passage 636...Sixth cooling passage A1...Air A2...Compressed air A3...Cooling fluid Ar...Axis Cg...Combustion gas flow path Da...Axial direction Dad...Axial downstream side Dad...Axial upstream side Dc...Circumferential direction Dr...Radial direction Dri...Radial inner side Dro...Radial outer side Dlc...Camber line direction Dwh...Blade height direction Dwhs...Hub side Dwht...Tip side F...Fuel G...Combustion gas Lca...Camber line P0...Reference position P1...First position P2...Second position P3...Third position P4...Fourth position P5...Fifth position P6...Sixth position P7...Seventh position P8...Eighth position P9...Ninth position P10...Tenth position P11...Eleventh position P12...Twelfth position P13...Thirteenth position P14...Fourteenth position P15...Fifteenth position P16...Sixteenth position P17...Seventeenth position P18...Eighteenth position P19...Nineteenth position P20...Tip position Ph...Hub side position Pm...Middle position Pt...Tip side position Rh...Hub side region Rpn...Abdominal / dorsal wall thickness ratio Rpn1...First abdominal / dorsal wall thickness ratio Rpn2...Second abdominal / dorsal wall thickness ratio Rpn3...Third abdominal / dorsal wall thickness ratio Rpn4...Fourth abdominal / dorsal wall thickness ratio Rpn5...Fifth abdominal / dorsal wall thickness ratio Rpn6...Sixth abdominal / dorsal wall thickness ratio Rt...Tip side region Tip...Tip side tipWn…dorsal wall thickness Wn1…first dorsal wall thickness Wn2…second dorsal wall thickness Wn3…third dorsal wall thickness Wn4…fourth dorsal wall thickness Wn5…fifth dorsal wall thickness Wn6…sixth dorsal wall thickness Wp…ventral wall thickness Wp1…first ventral wall thickness Wp2…second ventral wall thickness Wp3…third ventral wall thickness Wp4…fourth ventral wall thickness Wp5…fifth ventral wall thickness Wp6…sixth ventral wall thickness

Claims

1. A wing body having an airfoil-shaped cross section and extending in a wing height direction having a directional component perpendicular to the cross section; The wing body has a tip side and a hub side opposite to the tip side in the wing height direction, and the platform is provided at the end of the hub side; Equipped with The wing body is A leading edge and a trailing edge extending in the wing height direction and facing opposite sides to each other; A ventral side surface and a suction side surface extending in the wing height direction, connecting the leading edge and the trailing edge, and facing opposite sides to each other; One or more cooling passages located between the pressure side surface and the suction side surface and extending in the blade height direction; having a distance between an inner circumferential surface of the one or more cooling passages and the back side surface is a back wall thickness; a distance between an inner circumferential surface and the ventral surface of the one or more cooling passages is a ventral wall thickness; the ratio of the ventral wall thickness to the dorsal wall thickness is the ventral / dorsal wall thickness ratio; A position of 5 to 15% of a wing height, which is a distance from the platform to the tip end of the wing body, is a hub side position, A position of 25 to 35% of the wing height from the platform is an intermediate position; A position of 90 to 100% of the blade height from the platform is a tip side position, In any one of the one or more cooling passages, the width of the cooling passage at a position in the blade height direction of a hub side region between the hub side position and the intermediate position is smaller than the width of the cooling passage at a position in the blade height direction of a tip side region between the intermediate position and the tip side position, the one or more cooling passages include four or more cooling passages arranged in a camber line direction in which a camber line of the blade body extends, Among the four or more cooling passages, at least a front cooling passage located closest to the leading edge is the one cooling passage, The blade, wherein the pressure side wall thickness in the front cooling passage is maximum at the intermediate position in the blade height direction.

2. In the rotor blade according to claim 1, Among the four or more cooling passages, the thickness of the ventral side wall of each of the cooling passages other than the front cooling passage gradually increases from the tip side position toward the hub side position. Moving blade.

3. The rotor blade according to claim 1 , The average abdominal / back wall thickness ratio in the hub side region is less than the average abdominal / back wall thickness ratio in the tip side region. Moving blade.

4. The rotor blade according to any one of claims 1 to 3, A ratio of a change in the width / width ratio of the blade to the blade height direction in the hub side region is greater than a ratio of a change in the width / width ratio of the blade to the blade height direction in the tip side region. Moving blade.

5. The rotor blade according to claim 1 , The cooling passage has a portion including a part of the hub side region, the portion having the abdominal / back wall thickness ratio of less than 80%. Moving blade.

6. The rotor blade according to claim 1 , among the four or more cooling passages, the front cooling passage and one or more cooling passages connected to the front cooling passage form a front cooling passage group, a rear cooling passage located closest to the trailing edge and one or more cooling passages connected to the rear cooling passage among the four or more cooling passages form a rear cooling passage group, A portion of the abdominal / stern wall thickness ratio of 100% or more for each of the plurality of cooling passages included in the front-side cooling passage group and for each of the plurality of positions in the blade height direction is greater than a portion of the abdominal / stern wall thickness ratio of 100% or more for each of one or more cooling passages included in the rear-side cooling passage group and for each of the plurality of positions in the blade height direction. Moving blade.

7. The rotor blade according to claim 1 , among the four or more cooling passages, the front cooling passage and one or more cooling passages connected to the front cooling passage form a front cooling passage group, The pressure side wall thickness at any position in the blade height direction in the hub side region of the front cooling passage group becomes smaller from the cooling passage located closest to the trailing edge in the front cooling passage group toward the front cooling passage. Moving blade.

8. The rotor blade according to claim 1 , a rear cooling passage located closest to the trailing edge and one or more cooling passages connected to the rear cooling passage among the four or more cooling passages form a rear cooling passage group, The pressure side wall thickness at any position in the blade height direction in the hub side region of the rear cooling passage group becomes smaller from the cooling passage located closest to the leading edge in the rear cooling passage group toward the rear cooling passage. Moving blade.

9. The rotor blade according to any one of claims 1 to 3, In the one cooling passage, among the suction side wall thicknesses at each of a plurality of positions in the blade height direction, the suction side wall thickness at the tip side position is minimum, and the suction side wall thickness at the hub side position is maximum. Moving blade.

10. 10. The rotor blade of claim 9, The thickness of the rear wall of the first cooling passage gradually increases from the tip side position toward the hub side position. Moving blade.

11. A rotor blade according to any one of claims 1, 2, 3, 5, 6, 7, and 8 is provided, a rotor shaft that is rotatable about an axis and has a plurality of the rotor blades provided on an outer periphery thereof; a gas turbine casing covering the plurality of blades and the rotor shaft; Equipped Gas turbine.

Images