Rotary blades and gas turbines equipped with them

Abstract

The goal is to reduce the amount of cooling air used while increasing the durability of the control surfaces. [Solution] The cooling air passage of the rotor blade has a blade body passage and a plurality of tip ejection holes that open on the tip surface of the blade body and from which cooling air can be ejected from the blade body passage. Of the plurality of tip ejection holes, some of the plurality of 2-3 region ejection holes open in 2-3 region on the tip surface, and of the plurality of tip ejection holes, some of the plurality of 4-5 region ejection holes open in 4-5 region on the tip surface. The area density, which is the number of outlets in the plurality of 4-5 region ejection holes per unit area in the 4-5 region, is higher than the area density, which is the number of outlets in the plurality of 2-3 region ejection holes per unit area in the 2-3 region.

Description

Technical Field

[0001] The present invention relates to a moving blade and a gas turbine including the same.

Background Art

[0002] A gas turbine includes a compressor that compresses air to generate compressed air, a combustor that burns fuel in the compressed air to generate combustion gas, and a turbine that is driven by the combustion gas. The turbine includes a turbine rotor that rotates about an axis, a turbine casing that covers the rotor, and a plurality of stator blade rows. The turbine rotor has a rotor shaft centered on the axis and a plurality of moving blade rows attached to the rotor shaft. The plurality of moving blade rows are arranged in the axial direction in which the axis extends. Each moving blade row has a plurality of moving blades arranged in the circumferential direction with respect to the axis. The plurality of stator blade rows are arranged in the axial direction and attached to the inner circumferential side of the turbine casing. Each of the plurality of stator blade rows is disposed upstream of the axis of any one of the plurality of moving blade rows in the axial direction. Each stator blade row has a plurality of stator blades arranged in the circumferential direction with respect to the axis.

[0003] A moving blade generally has a blade body, a platform, and a blade root. The blade body has an airfoil-shaped cross section perpendicular to the radial direction with respect to the axis and extends in the radial direction. The platform is provided at the end on the inner side in the radial direction of the blade body. The blade root is provided on the inner side in the radial direction of the platform. The blade root is a portion for attaching the moving blade to the rotor shaft.

[0004] The moving blades of a gas turbine are exposed to high-temperature combustion gas. Therefore, the moving blades are generally cooled with air or the like.

[0005] For example, the rotor blade described in Patent Document 1 below has a cooling air passage formed in the stator blade body through which cooling air can flow. It has an introduction passage that opens at the surface of the blade root and through which cooling air can flow, and a blade body passage formed inside the blade body through which cooling air from the introduction passage can flow. The introduction passage has at least two introduction passage sections that extend in the blade height direction within the blade root and are aligned from the leading edge side to the trailing edge side. The blade body passage has a plurality of blade body passage sections that extend in the blade height direction within the blade body and are aligned along the camber line of the blade body from the leading edge side to the trailing edge side.

[0006] The multiple wing passage sections include a first wing passage section, a second wing passage section, a third wing passage section, a fourth wing passage section, a fifth wing passage section, and a sixth wing passage section. The first, second, third, fourth, fifth, and sixth wing passage sections are arranged in the above order from the leading edge to the trailing edge.

[0007] The hub-side portion of the first wing passage, which is closest to the leading edge of the six wing passages, is in communication with the hub-side portion of the second wing passage, which is adjacent to the first wing passage. The tip-side portion of the second wing passage is in communication with the tip-side portion of the third wing passage, which is adjacent to the second wing passage. The tip-side portion of the fourth wing passage, which is adjacent to the third wing passage, is in communication with the tip-side portion of the fifth wing passage, which is adjacent to the fourth wing passage. The hub-side portion of the fifth wing passage is in communication with the hub-side portion of the sixth wing passage, which is located closest to the trailing edge of the six wing passages and is adjacent to the fifth wing passage.

[0008] Of the two inlet passages, the first inlet passage on the leading edge side communicates with the hub-side portion of the third wing passage, and the second inlet passage on the trailing edge side communicates with the hub-side portion of the fourth wing passage.

[0009] Cooling air flowing into the first intake passage flows through the third wing passage, the second wing passage, and the first wing passage, and is ejected from the leading edge of the wing. Cooling air flowing into the second intake passage flows through the fourth wing passage, the fifth wing passage, and the sixth wing passage, and is ejected from the trailing edge of the wing. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2014-001633 (Figure 3) [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] In the rotor blade described in Patent Document 1, as mentioned above, the cooling air flowing into the first intake passage flows through the third wing passage, the second wing passage, and the first wing passage before being ejected from the leading edge of the wing. Also, in this rotor blade, as mentioned above, the cooling air flowing into the second intake passage flows through the fourth wing passage, the fifth wing passage, and the sixth wing passage before being ejected from the trailing edge of the wing. Therefore, in the rotor blade described in Patent Document 1, the rotor blade can be cooled while keeping the amount of cooling air to a minimum.

[0012] Incidentally, the rotor blades of a gas turbine, which are exposed to high-temperature combustion gases, are required to have high durability while minimizing the amount of cooling air used.

[0013] Therefore, the present disclosure aims to provide a rotor blade that can increase durability while reducing the amount of cooling air used, and a gas turbine equipped with this rotor blade. [Means for solving the problem]

[0014] A rotor blade according to one embodiment of the invention for achieving the above objective is: A wing body having an airfoil cross-section and extending in the wing height direction including a component perpendicular to the cross-section, The wing body comprises a platform provided at the hub end of the wing body, which is one of the tip side and hub side in the wing height direction; a wing root provided on the hub side of the platform; and a cooling air passage formed across the wing root, the platform, and the wing body, through which cooling air can flow. The wing body has a wing surface facing a direction having a directional component perpendicular to the wing height direction, and a tip surface facing the tip side in the wing height direction. The wing surface has a leading edge and a trailing edge extending in the wing height direction, and a positive pressure surface and a negative pressure surface extending in the wing height direction and extending from the leading edge to the trailing edge. The cooling air passage comprises an introduction passage formed at least within the wing root, a wing body passage formed at least within the wing body, and a plurality of tip ejection holes that open on the tip surface and from which cooling air can be ejected. The introduction passage has a first introduction passage section and a second introduction passage section. Both the first introduction passage section and the second introduction passage section have an inlet that opens on the surface of the wing root, and cooling air can flow in through the inlet. The wing passage extends in the wing height direction and has six wing passage sections arranged along the camber line of the wing, from the leading edge side to the trailing edge side, and a connecting section that connects two adjacent wing passage sections among the six wing passage sections. The six wing passages include a first wing passage closest to the leading edge, a second wing passage located closer to the trailing edge than the first wing passage and adjacent to the first wing passage, a third wing passage located closer to the trailing edge than the second wing passage and adjacent to the second wing passage, a fourth wing passage located closer to the trailing edge than the third wing passage and adjacent to the third wing passage, a fifth wing passage located closer to the trailing edge than the fourth wing passage and adjacent to the fourth wing passage, and a sixth wing passage located closest to the trailing edge and adjacent to the fifth wing passage. The aforementioned communication section includes a 1-2 hub-side communication section that connects the hub-side portion of the first wing passage section with the hub-side portion of the second wing passage section; a 2-3 tip-side communication section that connects the tip-side portion of the second wing passage section with the tip-side portion of the third wing passage section; a 4-5 tip-side communication section that connects the tip-side portion of the fourth wing passage section with the tip-side portion of the fifth wing passage section; and a 5-6 hub-side communication section that connects the hub-side portion of the fifth wing passage section with the hub-side portion of the sixth wing passage section. The first introduction passage communicates with the hub-side portion of the third wing passage, and the second introduction passage communicates with the hub-side portion of the fourth wing passage. The tip surface has a 2-3 region on the hub side of the tip surface where the second wing passage, the 2-3 tip-side communication portion, and the third wing passage are located, and a 4-5 region on the hub side of the tip surface where the fourth wing passage, the 4-5 tip-side communication portion, and the fifth wing passage are located. Of the plurality of chip ejection holes, some of the plurality of 2-3 region ejection holes have their outlets opening in the 2-3 region on the chip surface. Of the plurality of chip ejection holes, some of the other plurality of 4-5 region ejection holes have their outlets opening in the 4-5 region on the chip surface. The area density, which is the number of outlets in the multiple 4-5 region ejection holes per unit area in the 4-5 region, is higher than the area density, which is the number of outlets in the multiple 2-3 region ejection holes per unit area in the 2-3 region.

[0015] In this embodiment of the rotor blade, the cooling air flowing into the first intake passage flows through the third wing passage, the 2-3 tip-side communication section, the second wing passage, the 1-2 hub-side communication section, and the first wing passage, and as it flows through these passages and communication sections, it convectively cools the areas around these passages and communication sections. In this embodiment of the rotor blade, the cooling air flowing into the second intake passage flows through the fourth wing passage, the 4-5 tip-side communication section, the fifth wing passage, the 5-6 hub-side communication section, and the sixth wing passage, and as it flows through these passages and communication sections, it convectively cools the areas around these passages and communication sections. Therefore, in this embodiment of the rotor blade, the rotor blade can be cooled while keeping the amount of cooling air to a minimum.

[0016] Some of the combustion gases coming from the leading edge towards the blade flow along the positive pressure surface of the blade towards the trailing edge, while other parts flow along the negative pressure surface of the blade towards the trailing edge. With respect to the blade, the pressure of the combustion gases on the positive pressure surface is higher than that on the negative pressure surface. A circumferential force acts on the blade due to this pressure difference of the combustion gases. There is a gap between the tip surface of the blade and the turbine casing. As mentioned above, with respect to the blade, the pressure of the combustion gases on the positive pressure surface is higher than that on the negative pressure surface, so some of the combustion gases on the positive pressure surface flow into the gap between the tip surface and the turbine casing before flowing out to the negative pressure side. Therefore, the tip surface of the blade is also exposed to the high-temperature combustion gases.

[0017] The rotor blade in this embodiment has a plurality of tip ejection holes. A portion of the cooling air flowing through the blade passage flows into the plurality of tip ejection holes. As this cooling air flows through the tip ejection holes, it convectively cools the area around the tip ejection holes. The cooling air that has flowed through the plurality of tip ejection holes is ejected from the outlets of the tip ejection holes that are open on the tip surface. The cooling air ejected from the plurality of tip ejection holes cools the tip surface like a film.

[0018] Therefore, in this embodiment, thermal damage to the tip surface due to combustion gases can be suppressed, and the durability of the rotor blade can be improved.

[0019] As described above, there is a pressure difference between the combustion gas on the positive pressure surface side and the combustion gas on the negative pressure surface side with respect to the blade body. This pressure difference gradually increases and then gradually decreases as it goes from the leading edge to the trailing edge side of the blade body. The position where this pressure difference reaches its maximum is within the region where the fourth blade passage portion and the 4-5 chip side communication portion exist in the blade body. Therefore, within the blade body, the pressure difference in the region where the fourth blade passage portion, the 4-5 chip side communication portion, and the fifth blade passage portion exist is greater than the pressure difference in the region where the third blade passage portion, the 2-3 chip side communication portion, and the second blade passage portion exist. In this case, the flow velocity of the combustion gas passing through the 4-5 region on the chip surface is higher than the flow velocity of the combustion gas passing through the 2-3 region on the chip surface. When the flow velocity of the combustion gas is high, the heat transfer rate between the combustion gas and the blade body increases. Therefore, the heat transfer rate between the 4-5 region on the chip surface and the combustion gas is higher than the heat transfer rate between the 2-3 region on the chip surface and the combustion gas.

[0020] In this aspect, while reducing the exit area density of the 2-3 region ejection holes that open in the 2-3 region where the heat transfer rate is low on the chip surface, the exit area density of the 4-5 region ejection holes that open in the 4-5 region where the heat transfer rate is high on the chip surface is increased. As a result, in this aspect, the amount of cooling air ejected from the exit of the 2-3 region that is relatively difficult to be heated on the chip surface is suppressed, and the cooling performance for the 4-5 region that is relatively easily heated on the chip surface is enhanced. Therefore, in this embodiment, it is possible to enhance the durability of the moving blade while suppressing the amount of cooling air used.

[0021] A gas turbine according to an aspect of the invention for achieving the above object includes a plurality of moving blades in the above aspect, a rotor shaft that is rotatable about an axis and has the plurality of moving blades attached side by side in the circumferential direction with respect to the axis, and a turbine casing that covers the outer peripheral sides of the plurality of moving blades and the rotor shaft. The moving blade is attached to the rotor shaft such that the blade height direction is the radial direction with respect to the axis and the tip side is on the radially outer side with respect to the axis.

Effects of the Invention

[0022] According to one aspect of the present disclosure, it is possible to increase the durability of the moving blade while suppressing the amount of cooling air used.

Brief Description of the Drawings

[0023] [Figure 1] It is a schematic cross-sectional view of a gas turbine in an embodiment according to the present disclosure. [Figure 2] It is a perspective view of a moving blade in an embodiment according to the present disclosure. [Figure 3] It is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] It is a view seen in the direction of arrow IV in FIG. 2. [Figure 5] It is a cross-sectional view taken along line V-V in FIG. 4. [Figure 6] It is a cross-sectional view taken along line VI-VI in FIG. 4. [Figure 7] It is a cross-sectional view of the main part of a moving blade in a first modification of an embodiment according to the present disclosure. [Figure 8] It is a view of a moving blade in a second modification of an embodiment according to the present disclosure as seen from the radially outer side. [Figure 9] It is a view of a moving blade in a third modification of an embodiment according to the present disclosure as seen from the radially outer side.

Modes for Carrying Out the Invention

[0024] Hereinafter, embodiments of the moving blade of the present disclosure and a gas turbine including this moving blade will be described in detail with reference to the drawings.

[0025] 「Embodiment of Gas Turbine」 The embodiment of the gas turbine will be described with reference to FIG. 1.

[0026] As shown in FIG. 1, the gas turbine 10 of the present embodiment includes a compressor 20 that compresses air A, a combustor 30 that burns fuel F in the air A compressed by the compressor 20 to generate combustion gas G, and a turbine 40 that is driven by the combustion gas G.

[0027] The compressor 20 includes a compressor rotor 21 that rotates around the axis Ar, a compressor casing 25 that covers the compressor rotor 21, and a plurality of stator blade rows 26. The turbine 40 includes a turbine rotor 41 that rotates around the axis Ar, a turbine casing 45 that covers the turbine rotor 41, and a plurality of stator blade rows 46. In the following, the direction in which the axis Ar extends will be called the axial direction Da, the circumferential direction around this axis Ar will simply be called the circumferential direction Dc, and the direction perpendicular to the axis Ar will be called the radial direction Dr. Also, one side of the axial direction Da will be called the upstream side Dau, and the opposite side will be called the downstream side Dad. Also, the side of the radial direction Dr that approaches the axis Ar will be called the inner radial direction Dri, and the opposite side will be called the outer radial direction Dr.

[0028] The compressor 20 is positioned on the axial upstream side Dau relative to the turbine 40.

[0029] The compressor rotor 21 and the turbine rotor 41 are located on the same axis Ar and are connected to each other to form a gas turbine rotor 11. For example, the rotor of a generator GEN is connected to this gas turbine rotor 11. The gas turbine 10 further includes an intermediate casing 14. This intermediate casing 14 is located in the axial direction Da between the compressor casing 25 and the turbine casing 45. The compressor casing 25, the intermediate casing 14, and the turbine casing 45 are connected to each other to form a gas turbine casing 15.

[0030] The compressor rotor 21 has a rotor shaft 22 extending in the axial direction Da with respect to the axis Ar, and a plurality of rotor blade rows 23 attached to this rotor shaft 22. The plurality of rotor blade rows 23 are arranged in the axial direction Da. Each rotor blade row 23 is composed of a plurality of rotor blades arranged in the circumferential direction Dc. One of a plurality of stator blade rows 26 is positioned at the downstream Da of each rotor blade row 23 along the axis. Each stator blade row 26 is located inside the compressor casing 25. Each stator blade row 26 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0031] The turbine rotor 41 has a rotor shaft 42 extending in the axial direction Da with respect to the axis Ar, and a plurality of rotor blade rows 43 attached to the rotor shaft 42. The plurality of rotor blade rows 43 are arranged in the axial direction Da. Each rotor blade row 43 is composed of a plurality of rotor blades arranged in the circumferential direction Dc. One of a plurality of stator blade rows 46 is located upstream Dau of each rotor blade row. Each stator blade row 46 is located inside the turbine casing 45. Each stator blade row 46 is composed of a plurality of stator blades arranged in the circumferential direction Dc.

[0032] The combustor 30 is attached to the intermediate casing 14.

[0033] The compressor 20 compresses air A to produce compressed air. This compressed air flows into the combustor 30. Fuel F is supplied to the combustor 30. Inside the combustor 30, the fuel F burns in the compressed air to produce high-temperature, high-pressure combustion gas G. This combustion gas G is sent from the combustor 30 to the annular combustion gas flow path 49 inside the turbine casing 45. As the combustion gas G flows through the combustion gas flow path 49 toward the downstream side Da along the axis, it rotates the turbine rotor 41. This rotation of the turbine rotor 41 rotates the rotor of the generator GEN connected to the gas turbine rotor 11. As a result, the generator GEN generates electricity.

[0034] The following describes embodiments and modifications relating to the rotor blades constituting the rotor blade row 43 of the turbine 40.

[0035] "An embodiment of a control surface" One embodiment of the rotor blade will be described with reference to Figures 2 to 6.

[0036] As shown in Figures 2 to 4, the rotor blade 50 in this embodiment comprises a blade body 51, a platform 58, a blade root 59, and a cooling air passage 60.

[0037] The airfoil body 51 has an airfoil cross-section and extends in the airfoil height direction, which includes a component perpendicular to the cross-section. The airfoil body 51 has an airfoil surface 52 facing in a direction with a component perpendicular to the airfoil height direction, and a tip surface 55 facing the tip side of the airfoil height direction, which is the hub side of the tip side. The airfoil surface 52 has a leading edge 53f and a trailing edge 53b extending in the airfoil height direction, and a positive pressure surface 54p and a negative pressure surface 54n extending from the leading edge 53f to the trailing edge 53b. The positive pressure surface 54p and the negative pressure surface 54n are back to back. The positive pressure surface 54p is a concave surface, and the negative pressure surface 54n is a convex surface.

[0038] When this rotor blade 50 is attached to the rotor shaft 42 as described above, the blade body 51 will be located within the combustion gas passage 49 as described above using Figure 1. For this reason, the rotor blade 50 in this embodiment is equipped with a cooling air passage 60 through which cooling air Ac flows in order to cool the blade body 51.

[0039] When this rotor blade 50 is attached to the rotor shaft 42 mentioned above, the blade height direction becomes the radial direction Dr, the tip side becomes the radially outer Dro, and the hub side becomes the radially inner Dri. Also, the front side where the leading edge 53f exists relative to the trailing edge 53b becomes the upstream side Dau, and the rear side where the trailing edge 53b exists relative to the leading edge 53f becomes the downstream side Dad. Furthermore, the direction in which the positive pressure surface 54p and the negative pressure surface 54n are aligned becomes the circumferential direction Dc. Therefore, below, the blade height direction will be indicated as blade height direction Dr, the tip side as tip side Dro, and the hub side as hub side Dri. Also, the front side where the leading edge 53f exists relative to the trailing edge 53b will be indicated as front side Dau, and the rear side where the trailing edge 53b exists relative to the leading edge 53f will be indicated as rear side Dad.

[0040] The platform 58 is located on the hub side Dri of the wing body 51. This platform 58 is a rectangular plate-shaped member (see Figure 4) that extends in a direction that includes a directional component perpendicular to the wing height direction Dr.

[0041] The blade root 59 is located on the hub-side Dri of the platform 58. This blade root 59 is the part that attaches the rotor blade 50 to the rotor shaft 42. The cross-sectional shape of this blade root 59 is Christmas tree-shaped.

[0042] The cooling air passage 60 is formed over the wing root 59, platform 58, and wing body 51, and is a passage through which cooling air Ac can flow. This cooling air passage 60 has an introduction passage 61, a wing body passage 63, a plurality of forward ejection holes 66, a plurality of rear ejection holes 67, a plurality of tip ejection holes 68, a plurality of positive pressure side corner ejection holes 69p, and a plurality of negative pressure side corner ejection holes 69n.

[0043] As shown in Figures 2 and 3, the intake passage 61 has at least two intake passage sections 62 that extend in the wing height direction Dr within the wing root 59 and are aligned along the camber line CL of the wing body 51. Of the two intake passage sections 62, the first intake passage section 62a on the front side Dau and the second intake passage section 62b on the rear side Dad both have an inlet 62i that opens at the bottom surface 59b of the wing root 59, and cooling air Ac can flow in through this inlet 62i. The bottom surface 59b of the wing root 59 is the surface within the wing root 59 that faces the hub side Dri and is located furthest towards the hub side Dri.

[0044] The wing passage 63 extends in the wing height direction Dr within the wing body 51 and has six wing passage sections 64 arranged from the front Dau to the rear Dad along the camber line CL, and a connecting section 65 that connects two adjacent wing passage sections 64. Here, of the six wing passage sections 64, the wing passage section 64 at the foremost Dau is designated as the first wing passage section 64a, the wing passage section 64 located at Dad further back than the first wing passage section 64a and adjacent to the first wing passage section 64a is designated as the second wing passage section 64b, and the wing passage section 64 located at Dad further back than the second wing passage section 64b and adjacent to the second wing passage section 64b is designated as the third wing passage section 64c. Furthermore, of the six wing passage sections 64, the wing passage section 64 located further back Dad than the third wing passage section 64c and adjacent to the third wing passage section 64c is designated as the fourth wing passage section 64d, the wing passage section 64 located further back Dad than the fourth wing passage section 64d and adjacent to the fourth wing passage section 64d is designated as the fifth wing passage section 64e, and the wing passage section 64 located furthest back Dad and adjacent to the fifth wing passage section 64e is designated as the sixth wing passage section 64f.

[0045] The communication section 65 includes a 1-2 hub-side communication section 65a, a 2-3 tip-side communication section 65c, a 4-5 tip-side communication section 65d, and a 5-6 hub-side communication section 65e. The 1-2 hub-side communication section 65a connects the hub-side Dri portion of the first wing passage section 64a with the hub-side Dri portion of the second wing passage section 64b. The 2-3 tip-side communication section 65c connects the tip-side Dro portion of the second wing passage section 64b with the tip-side Dro portion of the third wing passage section 64c. The 4-5 tip-side communication section 65d connects the tip-side Dro portion of the fourth wing passage section 64d with the tip-side Dro portion of the fifth wing passage section 64e. The 5-6 hub-side connecting section 65e connects the hub-side Dri portion of the fifth wing passage section 64e with the hub-side Dri portion of the sixth wing passage section 64f.

[0046] The first introduction passage section 62a communicates with the hub-side Dri portion of the third wing passage section 64c, and the second introduction passage section 62b communicates with the hub-side Dri portion of the fourth wing passage section 64d.

[0047] Each of the multiple forward ejection holes 66 has an outlet that opens at the leading edge 53f or in the vicinity of the leading edge 53f in the wing surface 52, and a portion of the cooling air Ac flowing through the first wing passage 64a can be ejected from this outlet. Each of the multiple rear ejection holes 67 has an outlet that opens at the trailing edge 53b in the wing surface 52, and a portion of the cooling air Ac flowing through the sixth wing passage 64f can be ejected from this outlet.

[0048] As shown in Figures 2 to 6, each of the multiple tip ejection holes 68 has an outlet 68o (see Figure 2) that opens at the tip surface 55, and cooling air Ac from the wing passage 63 can be ejected from this outlet 68o. The outlets 68o of each of the multiple tip ejection holes 68 are arranged along the camber line CL from the front Dau to the rear Dad.

[0049] As shown in Figures 2, 4, and 5, each of the multiple positive pressure side corner ejection holes 69p has an outlet that opens at the positive pressure side corner 56p, which is the boundary between the positive pressure surface 54p and the tip surface 55, and cooling air Ac from the wing passage 63 can be ejected from this outlet. The outlets of each of the multiple positive pressure side corner ejection holes 69p are arranged at the positive pressure side corner 56p from the front Dau to the rear Dad. Each of the multiple negative pressure side corner ejection holes 69n has an outlet that opens at the negative pressure side corner 56n, which is the boundary between the negative pressure surface 54n and the tip surface 55, and cooling air Ac from the wing passage 63 can be ejected from this outlet. The outlets of each of the multiple negative pressure side corner ejection holes 69n are arranged at the negative pressure side corner 56n from the front Dau to the rear Dad.

[0050] Here, the region of the tip surface 55 where the first wing passage 64a exists on the hub-side Dri of the tip surface 55 is defined as region 1 55a. The region of the tip surface 55 where the second wing passage 64b, the 2-3 tip-side connecting section 65c, and the third wing passage 64c exist on the hub-side Dri of the tip surface 55 is defined as region 2-3 55c. The region of the tip surface 55 where the fourth wing passage 64d, the 4-5 tip-side connecting section 65d, and the fifth wing passage 64e exist on the hub-side Dri of the tip surface 55 is defined as region 4-5 55d. The region of the tip surface 55 where the sixth wing passage 64f exists on the hub-side Dri of the tip surface 55 is defined as region 6 55f. The number of outlets 68o in the tip ejection holes 68 per unit length of the camber line CL is defined as the linear density. In this embodiment, the length in the direction along the camber line CL in region 4-5 55d is longer than the length in the direction along the camber line CL in region 2-3 55c.

[0051] The outlet 68o of some of the 1-region ejection holes 68a among the multiple chip ejection holes 68 opens in a 1-region 55a on the chip surface 55. The 1-region ejection hole 68a can eject cooling air Ac that has flowed through the first wing passage 64a from this outlet 68o. The outlet 68o of some of the other 2-3 region ejection holes 68c among the multiple chip ejection holes 68 opens in a 2-3 region 55c on the chip surface 55. The outlet 68o of some of the 2-3 region ejection holes 68c can eject a portion of the cooling air Ac flowing through the third wing passage 64c, the 2-3 chip side communication section 65c, and the second wing passage 64b from this outlet 68o. The outlet 68o of some of the other 4-5 region ejection holes 68d among the multiple chip ejection holes 68 opens in a 4-5 region 55d on the chip surface 55. Multiple 4-5 region ejection holes 68d can eject a portion of the cooling air Ac flowing through the fourth wing passage 64d, the 4-5 tip side communication section 65d, and the fifth wing passage 64e from this outlet 68o.

[0052] The linear density at outlet 68o in vent 68d in region 4-5 is higher than the linear density at outlet 68o in vent 68c in region 2-3. Specifically, the linear density at outlet 68o in vent 68d in region 4-5 is more than 1.5 times and less than or equal to 2.5 times the linear density at outlet 68o in vent 68c in region 2-3. For example, the linear density at outlet 68o in vent 68d in region 4-5 is twice the linear density at outlet 68o in vent 68c in region 2-3.

[0053] Furthermore, the area density, which is the number of outlets 68o of multiple 4-5 region vents 68d per unit area in region 4-5 55d, is higher than the area density, which is the number of outlets 68o of multiple 2-3 region vents 68c per unit area in region 2-3 55c. Specifically, the area density of outlets 68o of 4-5 region vents 68d is more than twice the area density of outlets 68o of 2-3 region vents 68c, and less than or equal to 10 times. For example, the area density of outlets 68o of 4-5 region vents 68d is five times the area density of outlets 68o of 2-3 region vents 68c.

[0054] Cooling air Ac that flows into the first intake passage 62a flows into the third wing passage 64c. This cooling air Ac flows through the third wing passage 64c to the tip-side Dro, and in this process, convective cooling occurs around the third wing passage 64c. Cooling air Ac that has flowed through the third wing passage 64c flows into the 2-3 tip-side communication section 65c. Cooling air Ac that has flowed through the 2-3 tip-side communication section 65c flows into the second wing passage 64b. Cooling air Ac that has flowed through the second wing passage 64b flows to the hub-side Dri, and in this process, convective cooling occurs around the second wing passage 64b. The cooling air Ac that flows through the second wing passage 64b flows into the 1-2 hub side communication section 65a. This cooling air Ac flows from the 1-2 hub side communication section 65a to the front side Dau, and in this process, it convectively cools the area around the 1-2 hub side communication section 65a. The cooling air Ac that flows through the 1-2 hub side communication section 65a flows into the first wing passage 64a. This cooling air Ac flows from the first wing passage 64a to the tip side Dro, and in this process, it convectively cools the area around the first wing passage 64a. A portion of the cooling air Ac flowing through the first wing passage 64a flows into the multiple front ejection holes 66. This cooling air Ac flows through the multiple front ejection holes 66, and in this process, it convectively cools the area around the multiple front ejection holes 66. The cooling air Ac that flows through the multiple front ejection holes 66 is ejected from the outlets of the multiple front ejection holes 66. The cooling air Ac ejected from the multiple forward exhaust holes 66 cools the leading edge 53f of the blade surface 52.

[0055] The cooling air Ac that flows into the second introduction passage 62b flows into the fourth wing passage 64d. This cooling air Ac flows through the fourth wing passage 64d towards the tip-side Dro, and in this process, it provides convective cooling around the fourth wing passage 64d. The cooling air Ac that has flowed through the fourth wing passage 64d flows into the 4-5 tip-side communication section 65d. This cooling air Ac flows through the 4-5 tip-side communication section 65d towards the rear-side Dad, and in this process, it provides convective cooling around the 4-5 tip-side communication section 65d. The cooling air Ac that has flowed through the 4-5 tip-side communication section 65d flows into the fifth wing passage 64e. This cooling air Ac flows through the fifth wing passage 64e towards the hub-side Dri, and in this process, it provides convective cooling around the fifth wing passage 64e. The cooling air Ac that flows through the fifth wing passage 64e flows into the 5-6 hub side communication section 65e. This cooling air Ac flows from the 5-6 hub side communication section 65e to the rear side Dad, and in this process, it provides convective cooling around the 5-6 hub side communication section 65e. The cooling air Ac that flows through the 5-6 hub side communication section 65e flows into the sixth wing passage 64f. This cooling air Ac flows from the sixth wing passage 64f to the tip side Dro, and in this process, it provides convective cooling around the sixth wing passage 64f. A portion of the cooling air Ac flowing through the sixth wing passage 64f flows into the multiple rear ejection holes 67. This cooling air Ac flows through the multiple rear ejection holes 67, and in this process, it provides convective cooling around the multiple rear ejection holes 67. The cooling air Ac that flows through the multiple rear ejection holes 67 is ejected from the outlets of the multiple rear ejection holes 67. The cooling air Ac ejected from the multiple rear exhaust holes 67 cools the film around the trailing edge 53b of the blade surface 52.

[0056] As described above, in the rotor blade 50 of this embodiment, the cooling air Ac that flows into the first intake passage 62a flows through the third wing passage 64c, the 2-3 tip side communication section 65c, the second wing passage 64b, the 1-2 hub side communication section 65a, and the first wing passage 64a before being ejected from the leading edge 53f of the wing body 51. Also, in this rotor blade 50, as described above, the cooling air Ac that flows into the second intake passage 62b flows through the fourth wing passage 64d, the 4-5 tip side communication section 65d, the fifth wing passage 64e, the 5-6 hub side communication section 65e, and the sixth wing passage 64f before being ejected from the trailing edge 53b of the wing body 51. For this reason, in the rotor blade 50 of this embodiment, the rotor blade 50 can be cooled while suppressing the amount of cooling air Ac.

[0057] As shown in Figure 4, some of the combustion gas G coming from the front side Dau toward the blade 51 flows to the rear side Dad along the positive pressure surface 54p of the blade 51, and another portion flows to the rear side Dad along the negative pressure surface 54n of the blade 51. With respect to the blade 51, the pressure of the combustion gas G on the positive pressure surface 54p side is higher than the pressure of the combustion gas G on the negative pressure surface 54n side. Due to this pressure difference of the combustion gas G, a force Dc in the circumferential direction acts on the blade 51.

[0058] As shown in Figures 5 and 6, there is a gap between the tip surface 55 of the blade 51 and the turbine casing 45. As mentioned above, the pressure of the combustion gas G on the positive pressure side 54p is higher than the pressure of the combustion gas G on the negative pressure side 54n. Therefore, some of the combustion gas G on the positive pressure side 54p flows into the gap between the tip surface 55 and the turbine casing 45 and then flows out to the negative pressure side 54n. As a result, the tip surface 55 of the blade 51 is also exposed to the high-temperature combustion gas G.

[0059] In this embodiment, the rotor blade 50 has a plurality of tip ejection holes 68. A portion of the cooling air Ac flowing through the blade passage 63 flows into the plurality of tip ejection holes 68. As this cooling air Ac flows through the tip ejection holes 68, it convectively cools the area around the tip ejection holes 68. The cooling air Ac that has flowed through the plurality of tip ejection holes 68 is ejected from the outlet 68o of the tip ejection holes 68 which is open at the tip surface 55. The cooling air Ac ejected from the plurality of tip ejection holes 68 cools the tip surface 55 film.

[0060] Therefore, in this embodiment, thermal damage to the tip surface 55 due to combustion gas G can be suppressed, and the durability of the rotor blade 50 can be increased.

[0061] As mentioned above, the pressure of the combustion gas G on the positive pressure surface 54p is higher than the pressure of the combustion gas G on the negative pressure surface 54n, and there is a pressure difference between the combustion gas G on the positive pressure surface 54p and the combustion gas G on the negative pressure surface 54n, with respect to the airfoil 51. This pressure difference gradually increases and then decreases as you move from the leading edge 53f to the trailing edge 53b of the airfoil 51. The position where this pressure difference is maximum is within the region of the airfoil 51 where the fourth airfoil passage 64d and the 4-5 tip-side communication section 65d exist. For this reason, the pressure difference in the region of the airfoil 51 where the fourth airfoil passage 64d, the 4-5 tip-side communication section 65d and the fifth airfoil passage 64e exist is greater than the pressure difference in the region of the airfoil 51 where the third airfoil passage 64c, the 2-3 tip-side communication section 65c and the second airfoil passage 64b exist. In this case, the flow velocity of the combustion gas G passing through region 4-5 55d in the tip surface 55 is higher than the flow velocity of the combustion gas G passing through region 2-3 55c in the tip surface 55. When the flow velocity of the combustion gas G is high, the heat transfer coefficient between the combustion gas G and the blade 51 increases, so the heat transfer coefficient between region 4-5 55d in the tip surface 55 and the combustion gas G is higher than the heat transfer coefficient between region 2-3 55c in the tip surface 55 and the combustion gas G.

[0062] In this embodiment, the linear density of the outlet 68o of the 2-3 region ejection hole 68c, which opens in the 2-3 region 55c of the tip surface 55 where the heat transfer coefficient is low, is reduced, while the linear density of the outlet 68o of the 4-5 region ejection hole 68d, which opens in the 4-5 region 55d of the tip surface 55 where the heat transfer coefficient is high, is increased. As a result, in this embodiment, the amount of cooling air Ac ejected from the outlet 68o of the 2-3 region 55c, which is relatively less heated on the tip surface 55, is reduced, and the cooling performance for the 4-5 region 55d, which is relatively more easily heated on the tip surface 55, is improved. Therefore, in this embodiment, the durability of the rotor blade 50 can be increased while reducing the amount of cooling air Ac used.

[0063] The flow of combustion gas G along the positive pressure side corner 56p and along the negative pressure side corner 56n is turbulent. This is because the positive pressure side corner 56p is the location where combustion gas G from the positive pressure side 54p flows into the narrow gap between the tip surface 55 and the turbine casing 45, and the negative pressure side corner 56n is the location where combustion gas G flows out from the narrow gap between the tip surface 55 and the turbine casing 45 into the wider space on the negative pressure side 54n. The heat transfer coefficient between the combustion gas G and the blade 51 is high even in locations where the flow of combustion gas G is turbulent as described above. The rotor blade 50 in this embodiment has a positive pressure side corner ejection hole 69p that opens at the positive pressure side corner 56p where the heat transfer coefficient is relatively higher than in the surrounding area, and a negative pressure side corner ejection hole 69n that opens at the negative pressure side corner 56n where the heat transfer coefficient is relatively higher than in the surrounding area. Therefore, the cooling performance of the positive pressure side corner 56p and the negative pressure side corner 56n, which are more easily heated than the surrounding areas, can be improved.

[0064] The wingspan, which is the distance between the positive pressure surface 54p and the negative pressure surface 54n, gradually increases and then gradually decreases as you move from the leading edge 53f of the wing body 51 towards the trailing edge 53b. The position where this wingspan is maximum is closer to the leading edge 53f, within the region where the 2-3 tip side communication section 65c and the second wing body passage section 64b exist. In this relationship, the width of the 4-5 tip side communication section 65d in the wingspan direction is narrower than the width of the 2-3 tip side communication section 65c in the wingspan direction. Therefore, the flow velocity of the cooling air Ac flowing through the 4-5 tip side communication section 65d is higher than the flow velocity of the cooling air Ac flowing through the 2-3 tip side communication section 65c, and the convective cooling effect of the cooling air Ac flowing through the 4-5 tip side communication section 65d is higher than the convective cooling effect of the cooling air Ac flowing through the 2-3 tip side communication section 65c. In this embodiment, as described above, the length in the direction along the camber line CL in region 4-5 55d of the tip surface 55 is longer than the length in the direction along the camber line CL in region 2-3 55c of the tip surface 55. However, in this embodiment, the convective cooling effect on region 4-5 55d, which is relatively easily heated in the tip surface 55, is higher than the convective cooling effect on region 2-3 55c, which is relatively less easily heated in the tip surface 55. Therefore, in this embodiment, the durability of the rotor blade 50 can be increased from this viewpoint as well.

[0065] "First Modification of the Control Surface" As shown in Figure 7, the multiple 4-5 region ejection holes 68d may be inclined with respect to the tip surface 55 such that they gradually approach the trailing edge 53b as they move toward the tip side Dro. In this case, the length of the multiple 4-5 region ejection holes 68d becomes longer than the length of the multiple 4-5 region ejection holes 68d when they extend perpendicular to the tip surface 55. Also, the projected area of ​​the multiple 4-5 region ejection holes 68d with respect to the tip surface 55 becomes larger than the projected area of ​​the multiple 4-5 region ejection holes 68d when they extend perpendicular to the tip surface 55. Therefore, in this modification, a convective cooling effect can be applied by the cooling air Ac flowing through the multiple 4-5 region ejection holes 68d over a wide area of ​​the tip surface 55.

[0066] Furthermore, all of the multiple chip ejection holes 68 may be inclined with respect to the chip surface 55, similar to the modifications described above.

[0067] "Second and third modified versions of the control surface" In the embodiments described above, the outlets 68o of the multiple chip ejection holes 68 are all located on the camber line CL. However, the multiple chip ejection holes 68 do not have to be located on the camber line CL. For example, as shown in the second modified example in Figure 8, among the outlets 68o of the multiple 2-3 region ejection holes 68c in the 2-3 region 55c, one outlet 68o may be located on the positive pressure surface 54p side of the camber line CL, and the other outlet 68o may be located on the negative pressure surface 54n side of the camber line CL. Furthermore, among the outlets 68o of the multiple 4-5 region ejection holes 68d in the 4-5 region 55d, one outlet 68o may be located on the positive pressure surface 54p side of the camber line CL, and the other outlet 68o may be located on the negative pressure surface 54n side of the camber line CL. Furthermore, as shown in the third modified example in Figure 9, for example, the outlets 68o of the multiple 2-3 region ejection holes 68c in the 2-3 region 55c, and the outlets 68o of the multiple 4-5 region ejection holes 68d in the 4-5 region 55d, may both be located on the negative pressure surface 54n side of the camber line CL.

[0068] In addition, in the second and third modified examples described above, as in the embodiments described above, the area density, which is the number of outlets 68o of the multiple 4-5 region ejection holes 68d per unit area in the 4-5 region 55d, is higher than the area density, which is the number of outlets 68o of the multiple 2-3 region ejection holes 68c per unit area in the 2-3 region 55c. Specifically, the area density of the outlets 68o of the 4-5 region ejection holes 68d is more than twice the area density of the outlets 68o of the 2-3 region ejection holes 68c, and less than or equal to 10 times.

[0069] "Other variations" In the above embodiments, the rotor blade 50 has both a plurality of positive pressure side corner ejection holes 69p and a plurality of negative pressure side corner ejection holes 69n. However, at least one of the plurality of positive pressure side corner ejection holes 69p and the plurality of negative pressure side corner ejection holes 69n may be omitted. If only one of the plurality of positive pressure side corner ejection holes 69p and the plurality of negative pressure side corner ejection holes 69n is omitted, it is preferable to omit the plurality of negative pressure side corner ejection holes 69n and leave the plurality of positive pressure side corner ejection holes 69p.

[0070] This disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, partial deletions, etc., are possible without departing from the conceptual idea and spirit of the invention derived from the claims and their equivalents.

[0071] "Addendum" The rotor blades 50 in the above embodiments and modifications can be understood, for example, as follows.

[0072] (1) The rotor blade 50 in the first embodiment is The device comprises a wing body 51 having an airfoil cross-section and extending in the wing height direction Dr which includes a component perpendicular to the cross-section; a platform 58 provided at the end of the hub-side Dri of the wing body 51, which is part of the tip-side Dro and hub-side Dri in the wing height direction Dr; a wing root 59 provided on the hub-side Dri of the platform 58; and a cooling air passage 60 formed across the wing root 59, the platform 58, and the wing body 51, through which cooling air Ac can flow. The wing body 51 has a wing surface 52 facing a direction having a component perpendicular to the wing height direction Dr, and a tip surface 55 facing the tip side Dr in the wing height direction Dr. The wing surface 52 has a leading edge 53f and a trailing edge 53b extending in the wing height direction Dr, and a positive pressure surface 54p and a negative pressure surface 54n extending in the wing height direction Dr and extending from the leading edge 53f to the trailing edge 53b. The cooling air passage 60 includes an introduction passage 61 formed in at least the blade root 59, a blade passage 63 formed in at least the blade body 51, and a plurality of tip ejection holes 68 having an outlet 68o that opens at the tip surface 55, from which cooling air Ac can be ejected. The introduction passage 61 has a first introduction passage section 62a and a second introduction passage section 62b. Both the first introduction passage section 62a and the second introduction passage section 62b have an inlet 62i that opens on the surface of the wing root 59, and cooling air Ac can flow in through the inlet 62i. The wing passage 63 extends in the wing height direction Dr and has six wing passage sections 64 that are aligned along the camber line CL of the wing body 51, from the side of the leading edge 53f to the side of the trailing edge 53b, and a connecting section 65 that connects two adjacent wing passage sections 64. The six wing body passage sections 64 include a first wing body passage section 64a closest to the leading edge 53f, a second wing body passage section 64b located closer to the trailing edge 53b than the first wing body passage section 64a and adjacent to the first wing body passage section 64a, a third wing body passage section 64c located closer to the trailing edge 53b than the second wing body passage section 64b and adjacent to the second wing body passage section 64b, a fourth wing body passage section 64d located closer to the trailing edge 53b than the third wing body passage section 64c and adjacent to the third wing body passage section 64c, a fifth wing body passage section 64e located closer to the trailing edge 53b than the fourth wing body passage section 64d and adjacent to the fourth wing body passage section 64d, and a sixth wing body passage section 64f located closest to the trailing edge 53b and adjacent to the fifth wing body passage section 64e. The communication portion 65 includes a 1-2 hub-side communication portion 65a that connects the hub-side Dri portion of the first wing passage portion 64a with the hub-side Dri portion of the second wing passage portion 64b; a 2-3 tip-side communication portion 65c that connects the tip-side Dro portion of the second wing passage portion 64b with the tip-side Dro portion of the third wing passage portion 64c; a 4-5 tip-side communication portion 65d that connects the tip-side Dro portion of the fourth wing passage portion 64d with the tip-side Dro portion of the fifth wing passage portion 64e; and a 5-6 hub-side communication portion 65e that connects the hub-side Dri portion of the fifth wing passage portion 64e with the hub-side Dri portion of the sixth wing passage portion 64f. The first introduction passage 62a communicates with the hub-side Dri portion of the third wing passage 64c, and the second introduction passage 62b communicates with the hub-side Dri portion of the fourth wing passage 64d. The tip surface 55 has a 2-3 region 55c located on the hub side Dri of the tip surface 55, where the second wing passage portion 64b, the 2-3 tip side communication portion 65c, and the third wing passage portion 64c are located, and a 4-5 region 55d located on the hub side Dri of the tip surface 55, where the fourth wing passage portion 64d, the 4-5 tip side communication portion 65d, and the fifth wing passage portion 64e are located. Of the plurality of chip ejection holes 68, some of the plurality of 2-3 region ejection holes 68c have their outlets 68o open in the 2-3 region 55c of the chip surface 55. Of the plurality of chip ejection holes 68, some of the other plurality of 4-5 region ejection holes 68d have their outlets 68o open in the 4-5 region 55d of the chip surface 55. The area density, which is the number of outlets 68o of the multiple 4-5 region ejection holes 68d per unit area in the 4-5 region 55d, is higher than the area density, which is the number of outlets 68o of the multiple 2-3 region ejection holes 68c per unit area in the 2-3 region 55c.

[0073] In this embodiment of the rotor blade 50, the cooling air Ac flowing into the first intake passage 62a flows through the third wing passage 64c, the 2-3 tip side communication section 65c, the second wing passage 64b, the 1-2 hub side communication section 65a, and the first wing passage 64a, and in the process of flowing through these passages and communication sections, it provides convective cooling around these passages and communication sections. In this embodiment of the rotor blade 50, the cooling air Ac flowing into the second intake passage 62b flows through the fourth wing passage 64d, the 4-5 tip side communication section 65d, the fifth wing passage 64e, the 5-6 hub side communication section 65e, and the sixth wing passage 64f, and in the process of flowing through these passages and communication sections, it provides convective cooling around these passages and communication sections. Therefore, in this embodiment of the rotor blade 50, the rotor blade 50 can be cooled while keeping the amount of cooling air Ac low.

[0074] A portion of the combustion gas G coming from the leading edge 53f toward the blade 51 flows along the positive pressure surface 54p of the blade 51 toward the trailing edge 53b, while another portion flows along the negative pressure surface 54n of the blade 51 toward the trailing edge 53b. With respect to the blade 51, the pressure of the combustion gas G on the positive pressure surface 54p side is higher than the pressure of the combustion gas G on the negative pressure surface 54n side. A circumferential force Dc acts on the blade 51 due to this pressure difference of the combustion gas G. There is a gap between the tip surface 55 of the blade 51 and the turbine casing 45. As mentioned above, with respect to the blade 51, the pressure of the combustion gas G on the positive pressure surface 54p side is higher than the pressure of the combustion gas G on the negative pressure surface 54n side. Therefore, a portion of the combustion gas G on the positive pressure surface 54p side flows into the gap between the tip surface 55 and the turbine casing 45 and then flows out toward the negative pressure surface 54n side. Therefore, the tip surface 55 of the wing body 51 is also exposed to the high-temperature combustion gas G.

[0075] In this embodiment, the rotor blade 50 has a plurality of tip ejection holes 68. A portion of the cooling air Ac flowing through the blade passage 63 flows into the plurality of tip ejection holes 68. As this cooling air Ac flows through the tip ejection holes 68, it convectively cools the area around the tip ejection holes 68. The cooling air Ac that has flowed through the plurality of tip ejection holes 68 is ejected from the outlet 68o of the tip ejection holes 68 which is open at the tip surface 55. The cooling air Ac ejected from the plurality of tip ejection holes 68 cools the tip surface 55 film.

[0076] Therefore, in this embodiment, thermal damage to the tip surface 55 due to combustion gas G can be suppressed, and the durability of the rotor blade 50 can be increased.

[0077] As mentioned above, there is a pressure difference between the combustion gas G on the positive pressure side 54p and the combustion gas G on the negative pressure side 54n, with respect to the airfoil 51. This pressure difference gradually increases and then decreases as you move from the leading edge 53f to the trailing edge 53b of the airfoil 51. The position where this pressure difference is maximum is within the region of the airfoil 51 where the fourth airfoil passage 64d and the 4-5 tip side communication section 65d exist. Therefore, the pressure difference in the region of the airfoil 51 where the fourth airfoil passage 64d, the 4-5 tip side communication section 65d and the fifth airfoil passage 64e exist is greater than the pressure difference in the region of the airfoil 51 where the third airfoil passage 64c, the 2-3 tip side communication section 65c and the second airfoil passage 64b exist. In this case, the flow velocity of the combustion gas G passing through region 4-5 55d in the tip surface 55 is higher than the flow velocity of the combustion gas G passing through region 2-3 55c in the tip surface 55. When the flow velocity of the combustion gas G is high, the heat transfer coefficient between the combustion gas G and the blade 51 increases, so the heat transfer coefficient between region 4-5 55d in the tip surface 55 and the combustion gas G is higher than the heat transfer coefficient between region 2-3 55c in the tip surface 55 and the combustion gas G.

[0078] In this embodiment, the area density of the outlet 68o of the 2-3 region ejection hole 68c, which opens in the 2-3 region 55c of the tip surface 55 where the heat transfer coefficient is low, is reduced, while the area density of the outlet 68o of the 4-5 region ejection hole 68d, which opens in the 4-5 region 55d of the tip surface 55 where the heat transfer coefficient is high, is increased. As a result, in this embodiment, the amount of cooling air Ac ejected from the outlet 68o of the 2-3 region 55c, which is relatively less heated on the tip surface 55, is reduced, and the cooling performance for the 4-5 region 55d, which is relatively more easily heated on the tip surface 55, is improved. Therefore, in this embodiment, the durability of the rotor blade 50 can be increased while reducing the amount of cooling air Ac used.

[0079] (2) The rotor blade 50 in the second embodiment is In the rotor blade according to the first embodiment, the area density of the outlet in the plurality of 4-5 region ejection holes is at least twice the area density of the outlet in the plurality of 2-3 region ejection holes.

[0080] (3) The rotor blade 50 in the third embodiment is In the rotor blade according to the second embodiment, the area density of the outlet in the plurality of 4-5 region ejection holes is 10 times or less the area density of the outlet in the plurality of 2-3 region ejection holes.

[0081] (4) In the fourth embodiment, the rotor blade 50 is In the rotor blade 50 in any one of the first to third embodiments, The outlets 68o of each of the plurality of chip ejection holes 68 are aligned along the camber line CL, from the leading edge 53f side to the trailing edge 53b side. If the number of outlets 68o in the plurality of chip ejection holes 68 per unit length of the camber line CL is defined as the linear density, then the linear density of the outlets 68o in the plurality of 4-5 region ejection holes 68d is higher than the linear density of the outlets 68o in the plurality of 2-3 region ejection holes 68c.

[0082] (5) In the fifth embodiment, the rotor blade 50 is In the rotor blade 50 of the fourth embodiment, the length in the direction along the camber line CL in the 4-5 region 55d is longer than the length in the direction along the camber line CL in the 2-3 region 55c.

[0083] The wingspan, which is the distance between the positive pressure surface 54p and the negative pressure surface 54n, gradually increases and then gradually decreases as you move from the leading edge 53f of the wing body 51 towards the trailing edge 53b. The position where this wingspan is maximum is closer to the leading edge 53f, within the region where the 2-3 tip side communication section 65c and the second wing body passage section 64b exist. In this relationship, the width of the 4-5 tip side communication section 65d in the wingspan direction is narrower than the width of the 2-3 tip side communication section 65c in the wingspan direction. Therefore, the flow velocity of the cooling air Ac flowing through the 4-5 tip side communication section 65d is higher than the flow velocity of the cooling air Ac flowing through the 2-3 tip side communication section 65c, and the convective cooling effect of the cooling air Ac flowing through the 4-5 tip side communication section 65d is higher than the convective cooling effect of the cooling air Ac flowing through the 2-3 tip side communication section 65c. In this embodiment, the length in the direction along the camber line CL in region 4-5 55d of the tip surface 55 is longer than the length in the direction along the camber line CL in region 2-3 55c of the tip surface 55. However, in this embodiment, the convective cooling effect on region 4-5 55d, which is relatively easily heated in the tip surface 55, is higher than the convective cooling effect on region 2-3 55c, which is relatively less easily heated in the tip surface 55. Therefore, in this embodiment, the durability of the rotor blade 50 can be increased.

[0084] (6) The rotor blade 50 in the sixth embodiment is In the rotor blade 50 according to the fourth or fifth embodiment, the linear density of the outlet 68o in the plurality of 4-5 region ejection holes 68d is 1.5 times or more the linear density of the outlet 68o in the plurality of 2-3 region ejection holes 68c.

[0085] (7) The rotor blade 50 in the seventh embodiment is In the rotor blade 50 of the sixth embodiment, the linear density of the outlet 68o in the plurality of 4-5 region ejection holes 68d is 2.5 times or less the linear density of the outlet 68o in the plurality of 2-3 region ejection holes 68c.

[0086] (8) The rotor blade 50 in the eighth aspect is In the rotor blade 50 in any one of the first to seventh embodiments, at least the plurality of 4-5 region ejection holes 68d of the plurality of tip ejection holes 68 are inclined with respect to the tip surface 55 such that they gradually approach the trailing edge 53b as they move toward the tip side Dro.

[0087] In this embodiment, the length of the multiple 4-5 region ejection holes 68d is longer than the length of the multiple 4-5 region ejection holes 68d when they extend perpendicular to the chip surface 55. Also, in this embodiment, the projected area of ​​the multiple 4-5 region ejection holes 68d with respect to the chip surface 55 is larger than the projected area of ​​the multiple 4-5 region ejection holes 68d when they extend perpendicular to the chip surface 55. Therefore, in this embodiment, a convective cooling effect can be applied over a wide area of ​​the chip surface 55 by the cooling air Ac flowing through the multiple 4-5 region ejection holes 68d.

[0088] (9) The rotor blade 50 in the ninth aspect is In the rotor blade 50 in any one of the first to eight embodiments described above, the cooling air passage 60 has an outlet that opens at the positive pressure side corner 56p which is the boundary between the positive pressure surface 54p and the tip surface 55, and has a plurality of positive pressure side corner ejection holes 69p arranged from the leading edge 53f to the trailing edge 53b, from which cooling air Ac from the blade passage 63 can be ejected from the outlet at the positive pressure side corner 56p.

[0089] The flow of combustion gas G along the positive pressure side corner 56p is turbulent. This is because the positive pressure side corner 56p is the location where the combustion gas G from the positive pressure surface 54p flows into the narrow gap between the tip surface 55 and the turbine casing 45. The heat transfer coefficient between the combustion gas G and the blade 51 is high even in the area where the flow of combustion gas G is turbulent as described above. In this embodiment, the rotor blade 50 has a positive pressure side corner ejection hole 69p that opens at the positive pressure side corner 56p, where the heat transfer coefficient is relatively higher than in the surrounding area. Therefore, in this embodiment, the cooling performance of the positive pressure side corner 56p, which is more easily heated than the surrounding area, can be improved.

[0090] (10) In the tenth embodiment, the rotor blade 50 is In the rotor blade 50 in any one of the first to ninth embodiments, the cooling air passage 60 has an outlet that opens at the negative pressure side corner 56n which is the boundary between the negative pressure surface 54n and the tip surface 55, and has a plurality of negative pressure side corner ejection holes 69n arranged from the leading edge 53f to the trailing edge 53b, from which cooling air Ac from the blade passage 63 can be ejected from the outlet at the negative pressure side corner 56n.

[0091] The flow of combustion gas G along the negative pressure side corner 56n is turbulent. This is because the negative pressure side corner 56n is the location where the gas flows out from the narrow gap between the tip surface 55 and the turbine casing 45 into the wider space on the negative pressure side 54n. The heat transfer coefficient between the combustion gas G and the blade 51 is high even in the area where the flow of combustion gas G is turbulent as described above. In this embodiment, the rotor blade 50 has a negative pressure side corner ejection hole 69n that opens at the negative pressure side corner 56n, where the heat transfer coefficient is relatively higher than in the surrounding area. Therefore, in this embodiment, the cooling performance of the negative pressure side corner 56n, which is more easily heated than the surrounding area, can be improved.

[0092] The gas turbine 10 in the above embodiments and modifications can be understood, for example, as follows. (11) The gas turbine 10 in the eleventh embodiment is The turbine comprises a rotor shaft 42 having a plurality of rotor blades 50 according to any one of the first to tenth embodiments, and being rotatable about an axis Ar, with the plurality of rotor blades 50 mounted in a circumferential direction Dc with respect to the axis Ar, and a turbine casing 45 covering the outer circumference of the plurality of rotor blades 50 and the rotor shaft 42. The rotor blades 50 are mounted on the rotor shaft 42 such that the blade height direction Dr is radial with respect to the axis Ar, and the tip side Dro is radially outward with respect to the axis Ar. [Explanation of Symbols]

[0093] 10: Gas Turbine 11: Gas turbine rotor 14: Intermediate casing 15: Gas turbine casing 20: Compressor 21: Compressor rotor 22: Rotor shaft 23: Moving blade row 25: Compressor casing 26: Stator Wing Arrow 30: Combustor 40: Turbine 41: Turbine Rotor 42: Rotor shaft 43: Moving blade row 45: Turbine casing 49: Combustion gas flow path 50: Moving blade 51: Wing body 52: Wing surface 53f: Leading edge 53b: Trailing edge 54n: Negative pressure side 54p: Positive pressure side 55: Chip surface 55a:1 area 55c:2-3 area 55d:4-5 area 55f:6 area 56n: Negative pressure side corner 56p: Positive pressure side corner 58: Platform 59: Wing root 59b: Bottom 60: Cooling air passage 61: Introduction passage 62: Introduction passage 62a: First introduction passage section 62b:Second introduction passage section 62i:Entrance 63: Wing passage 64: Wing body passage section 64a: First wing passage section 64b: Second wing passage section 64c:Third wing passage section 64d: Fourth wing passage section 64e: Fifth wing passage section 64f: Sixth wing passage section 65:Communication part 65a: 1-2 Hub side communication section 65c:2-3 Chip side communication section 65d: 4-5 Chip side communication section 65e:5-6 Hub-side connecting section 66: Front vent 67: Post-spout hole 68: Tip ejection hole 68o:Exit 68a:1 area vent 68c:2-3 area vent 68d:4-5 area vent 69n: Negative pressure side corner ejection hole 69p: Positive pressure side corner nozzle A: Air AC: Cooling air F:Fuel G: Combustion gas Ar: Axis line CL: Camber line Da: Axial direction Dau: Front side (or upstream side of the axis) Dad: Rear side (or downstream side of the axis) Dc: Circumferential direction Dr: Wing height direction (or radial direction) Dri: Hub side (or radially inward) Dro: Tip side (or radially outward)

Claims

1. A wing body having an airfoil cross-section and extending in the wing height direction including a component perpendicular to the cross-section, Of the tip side and hub side in the wing height direction, a platform is provided at the hub side end of the wing body, The wing root provided on the hub side of the aforementioned platform, A cooling air passage is formed extending from the wing root, the platform, and the wing body, through which cooling air can flow, Equipped with, The wing body has a wing surface facing a direction having a directional component perpendicular to the wing height direction, and a tip surface facing the tip side in the wing height direction, The wing surface has a leading edge and a trailing edge extending in the wing height direction, and a positive pressure surface and a negative pressure surface extending in the wing height direction and extending from the leading edge to the trailing edge. The aforementioned cooling air passage is An introduction passage formed at least within the wing root, A wing passage formed at least within the wing body, It has an outlet that opens on the tip surface, and a plurality of tip ejection holes from which cooling air can be ejected, The aforementioned introduction passage has a first introduction passage section and a second introduction passage section. Both the first and second introduction passages have inlets that open on the surface of the wing roots, and cooling air can flow in through these inlets. The wing passage extends in the wing height direction and has six wing passage sections arranged along the camber line of the wing from the leading edge to the trailing edge, and a connecting section that connects two adjacent wing passage sections among the six wing passage sections. The six wing passages include a first wing passage closest to the leading edge, a second wing passage located closer to the trailing edge than the first wing passage and adjacent to the first wing passage, a third wing passage located closer to the trailing edge than the second wing passage and adjacent to the second wing passage, a fourth wing passage located closer to the trailing edge than the third wing passage and adjacent to the third wing passage, a fifth wing passage located closer to the trailing edge than the fourth wing passage and adjacent to the fourth wing passage, and a sixth wing passage located closest to the trailing edge and adjacent to the fifth wing passage. The aforementioned communication portion is, A 1-2 hub-side connecting section connects the hub-side portion of the first wing passage section and the hub-side portion of the second wing passage section, A 2-3 tip-side connecting portion connects the tip-side portion of the second wing passage and the tip-side portion of the third wing passage, The tip-side portion of the four-wing passage section and the tip-side portion of the fifth-wing passage section are connected by a 4-5 tip-side connecting portion. A 5-6 hub-side connecting section connects the hub-side portion of the five-wing passage section and the hub-side portion of the six-wing passage section, It has, The first introduction passage section communicates with the hub-side portion of the third wing passage section, and the second introduction passage section communicates with the hub-side portion of the fourth wing passage section. The tip surface has a 2-3 region on the hub side of the tip surface where the second wing passage, the 2-3 tip-side communication portion, and the third wing passage are located, and a 4-5 region on the hub side of the tip surface where the fourth wing passage, the 4-5 tip-side communication portion, and the fifth wing passage are located. Of the plurality of chip ejection holes, some of the plurality of 2-3 region ejection holes have an outlet that opens in the 2-3 region on the chip surface. Of the plurality of chip ejection holes, some of the other plurality of 4-5 region ejection holes have their outlets open in the 4-5 region on the chip surface. The area density, which is the number of outlets in the multiple 4-5 region ejection holes per unit area in the 4-5 region, is higher than the area density, which is the number of outlets in the multiple 2-3 region ejection holes per unit area in the 2-3 region. Moving blade.

2. In the rotor blade described in claim 1, The area density of the outlets in the plurality of 4-5 region ejection holes is at least twice the area density of the outlets in the plurality of 2-3 region ejection holes. Moving blade.

3. In the rotor blade described in claim 2, The area density of the outlets in the plurality of 4-5 region ejection holes is 10 times or less the area density of the outlets in the plurality of 2-3 region ejection holes. Moving blade.

4. In the rotor blade according to any one of claims 1 to 3, The outlets of each of the plurality of chip ejection holes are aligned along the camber line, from the leading edge side to the trailing edge side. If the linear density is defined as the number of outlets in the plurality of chip ejection holes per unit length of the camber line, then the linear density of the outlets in the plurality of 4-5 region ejection holes is higher than the linear density of the outlets in the plurality of 2-3 region ejection holes. Moving blade.

5. In the rotor blade according to claim 4, The length in the direction along the camber line in the 4-5 region is longer than the length in the direction along the camber line in the 2-3 region. Moving blade.

6. In the rotor blade according to claim 4, The linear density at the outlets of the plurality of 4-5 region ejection holes is 1.5 times or more the linear density at the outlets of the plurality of 2-3 region ejection holes. Moving blade.

7. In the rotor blade according to claim 6, The linear density at the outlets of the plurality of 4-5 region ejection holes is 2.5 times or less the linear density at the outlets of the plurality of 2-3 region ejection holes. Moving blade.

8. In the rotor blade according to any one of claims 1 to 3, Of the plurality of chip ejection holes, at least the plurality of 4-5 region ejection holes are inclined with respect to the chip surface such that they gradually approach the trailing edge side as they move toward the chip side. Moving blade.

9. In the rotor blade according to any one of claims 1 to 3, The cooling air passage has an outlet that opens at the positive pressure side corner, which is the boundary between the positive pressure surface and the tip surface, and has a plurality of positive pressure side corner ejection holes arranged from the leading edge to the trailing edge, which allow cooling air from the wing passage to be ejected from the outlet at the positive pressure side corner. Moving blade.

10. In the rotor blade according to any one of claims 1 to 3, The cooling air passage has an outlet that opens at the negative pressure side corner, which is the boundary between the negative pressure surface and the tip surface, and has a plurality of negative pressure side corner ejection holes arranged from the leading edge to the trailing edge, which allow cooling air from the wing passage to be ejected from the outlet at the negative pressure side corner. Moving blade.

11. The device comprises a plurality of rotor blades as described in any one of claims 1 to 3, A rotor shaft that is rotatable about an axis, and on which multiple rotor blades are mounted in a circumferential direction relative to the axis, A turbine casing that covers the outer circumference of the multiple rotor blades and the rotor shaft, Equipped with, The rotor blade is mounted on the rotor shaft such that the blade height direction is radial to the axis, and the tip side is radially outward with respect to the axis. Gas turbine.

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