Rotating blade and gas turbine equipped with same

Abstract

To improve the durability of rotor blades while reducing the amount of cooling air used. [Solution] A cooling air passage of a blade has a blade-body passage and a plurality of tip nozzles that open on a tip surface of the blade body and can eject cooling air from the blade-body passage. A portion of the plurality of tip nozzles, namely, a plurality of 2-3 region nozzles, open in the 2-3 region of the tip surface, and another portion of the plurality of tip nozzles, namely, a plurality of 4-5 region nozzles, open in the 4-5 region of the tip surface. An area density, which is the number of outlets in the plurality of 4-5 region nozzles per unit area in the 4-5 region, is higher than an area density, which is the number of outlets in the plurality of 2-3 region nozzles per unit area in the 2-3 region.

Description

[Technical field]

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

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

[0003] A rotor blade generally has a blade body, a platform, and a blade root. The blade body has an airfoil shape in a cross section perpendicular to the radial direction relative to the axis and extends in the radial direction. The platform is provided at the end of the blade body on the radial inside. The blade root is provided on the radial inside of the platform. This blade root is the part that attaches the rotor blade to the rotor shaft.

[0004] The rotor blades of a gas turbine are exposed to high-temperature combustion gases, and therefore are generally cooled by air or the like.

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

[0006] The plurality of blade passages include a first blade passage, a second blade passage, a third blade passage, a fourth blade passage, a fifth blade passage, and a sixth blade passage, the first blade passage, the second blade passage, the third blade passage, the fourth blade passage, the fifth blade passage, and the sixth blade passage being arranged in this order from the leading edge side to the trailing edge side.

[0007] The hub side portion of the first blade passage section, which is the most leading of the six blade passage sections, communicates with the hub side portion of the second blade passage section adjacent to the first blade passage section. The tip side portion of the second blade passage section and the tip side portion of the third blade passage section adjacent to the second blade passage section communicate with each other. The tip side portion of the fourth blade passage section adjacent to the third blade passage section and the tip side portion of the fifth blade passage section adjacent to the fourth blade passage section communicate with each other. The hub side portion of the fifth blade passage section and the hub side portion of the sixth blade passage section, which is the most trailing of the six blade passage sections and adjacent to the fifth blade passage section, communicate with each other.

[0008] Of the two introduction passage sections, the first introduction passage section on the leading edge side is connected to the hub side portion of the third blade passage section, and the second introduction passage section on the trailing edge side is connected to the hub side portion of the fourth blade passage section.

[0009] The cooling air that flows into the first inlet passage flows through the third, second and first blade passages and is ejected from the leading edge of the blade, while the cooling air that flows into the second inlet passage flows through the fourth, fifth and sixth blade passages and is ejected from the trailing edge of the blade. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] JP 2014-001633 A (Fig. 3) Summary of the Invention [Problem to be solved by the invention]

[0011] In the blade described in Patent Document 1, as described above, the cooling air that flows into the first introduction passage flows through the third blade passage, the second blade passage, and the first blade passage, and is then ejected from the leading edge of the blade. Also, in this blade, as described above, the cooling air that flows into the second introduction passage flows through the fourth blade passage, the fifth blade passage, and the sixth blade passage, and is then ejected from the trailing edge of the blade. Therefore, in the blade described in Patent Document 1, the blade can be cooled while suppressing the amount of cooling air.

[0012] Incidentally, moving blades of gas turbines exposed to high-temperature combustion gases are required to have high durability while reducing the amount of cooling air used.

[0013] In view of the above, an object of the present disclosure is to provide a rotor blade capable of increasing durability while reducing the amount of cooling air used, and a gas turbine including such a rotor blade. [Means for solving the problem]

[0014] In order to achieve the above object, one aspect of the invention relates to a rotor blade, A wing body having a cross section that forms an airfoil shape and extends in a wing height direction that includes a directional component perpendicular to the cross section; The blade has a platform provided at the hub side end of the blade body, between the tip side and the hub side in the blade height direction, a blade root provided on the hub side of the platform, and a cooling air passage formed across the blade root, the platform and the blade body, through which cooling air can flow. The blade body has a blade surface facing a direction having a directional component perpendicular to the blade height direction, and a tip surface facing the tip side in the blade height direction. The blade surface has a leading edge and a trailing edge extending in the blade height direction, and a pressure side and a suction side extending in the blade height direction and expanding from the leading edge to the trailing edge. The cooling air passage includes an introduction passage formed at least in the blade root, a blade body passage formed at least in the blade body, and a plurality of tip outlets having outlets opening at the tip surface and capable of ejecting cooling air from the outlets. The introduction passage has a first introduction passage portion and a second introduction passage portion. The first introduction passage portion and the second introduction passage portion each have an inlet that opens on the surface of the blade root and through which cooling air can flow. The blade passage has six blade passage sections extending in the blade height direction and aligned along the camber line of the blade from the leading edge side to the trailing edge side, and a communication section that connects two adjacent blade passage sections among the six blade passage sections. The six wing passage sections include a first wing passage section closest to the leading edge, a second wing passage section located closer to the trailing edge than the first wing passage section and adjacent to the first wing passage section, a third wing passage section located closer to the trailing edge than the second wing passage section and adjacent to the second wing passage section, a fourth wing passage section located closer to the trailing edge than the third wing passage section and adjacent to the third wing passage section, a fifth wing passage section located closer to the trailing edge than the fourth wing passage section and adjacent to the fourth wing passage section, and a sixth wing passage section located closest to the trailing edge and adjacent to the fifth wing passage section. The communicating portions include a 1-2 hub side communicating portion that communicates the hub side portion of the first blade passage portion with the hub side portion of the second blade passage portion, a 2-3 tip side communicating portion that communicates the tip side portion of the second blade passage portion with the tip side portion of the third blade passage portion, a 4-5 tip side communicating portion that communicates the tip side portion of the fourth blade passage portion with the tip side portion of the fifth blade passage portion, and a 5-6 hub side communicating portion that communicates the hub side portion of the fifth blade passage portion with the hub side portion of the sixth blade passage portion. The first inlet passage portion communicates with a hub-side portion of the third blade passage portion, and the second inlet passage portion communicates with a hub-side portion of the fourth blade passage portion. The tip surface has a 2-3 region on the hub side of the tip surface where the second blade passage portion, the 2-3 tip side communication portion, and the third blade passage portion are present, and a 4-5 region on the hub side of the tip surface where the fourth blade passage portion, the 4-5 tip side communication portion, and the fifth blade passage portion are present. Among the plurality of tip jet holes, a portion of the plurality of 2-3 region jet holes have their outlets open in the 2-3 region of the tip surface, and among the plurality of tip jet holes, a portion of the plurality of 4-5 region jet holes have their outlets open in the 4-5 region of the tip surface. The area density, which is the number of outlets in the plurality of 4-5 area orifices per unit area in the 4-5 area, is higher than the area density, which is the number of outlets in the plurality of 2-3 area orifices per unit area in the 2-3 area.

[0015] In the blade of this embodiment, the cooling air that flows into the first introduction passage flows through the third blade passage, the 2-3 tip side communicating portion, the second blade passage, the 1-2 hub side communicating portion, and the first blade passage, and in the process of flowing through these passages and communicating portions, convectively cools the surroundings of these passages and communicating portions. In the blade of this embodiment, the cooling air that flows into the second introduction passage flows through the fourth blade passage, the 4-5 tip side communicating portion, the fifth blade passage, the 5-6 hub side communicating portion, and the sixth blade passage, and in the process of flowing through these passages and communicating portions, convectively cools the surroundings of these passages and communicating portions. Therefore, in the blade of this embodiment, the amount of cooling air is suppressed while the blade is cooled.

[0016] A part of the combustion gas coming from the leading edge side toward the blade body flows along the pressure side of the blade body to the trailing edge side, and the other part flows along the suction side of the blade body to the trailing edge side. The pressure of the combustion gas on the pressure side is higher than that on the suction side of the blade body relative to the blade body. A circumferential force acts on the blade body due to the combustion gas pressure difference. There is a gap between the tip surface of the blade body and the turbine casing. As described above, the pressure of the combustion gas on the pressure side is higher than that on the suction side of the blade body relative to the blade body, so that a part of the combustion gas on the pressure side flows into the gap between the tip surface and the turbine casing and then flows out to the suction side. Therefore, the tip surface of the blade body is also exposed to the high-temperature combustion gas.

[0017] The blade in this embodiment has a plurality of tip ejection holes. A portion of the cooling air flowing through the blade body passage flows into the plurality of tip ejection holes. This cooling air convectively cools the periphery of the tip ejection holes while flowing through 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 open on the tip surface. The cooling air ejected from the plurality of tip ejection holes performs film cooling on the tip surface.

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

[0019] As described above, there is a pressure difference between the combustion gas on the pressure side and the combustion gas on the suction side with respect to the blade body. This pressure difference gradually increases and then gradually decreases from the leading edge of the blade body to the trailing edge side. The position where this pressure difference is maximum is in the area where the fourth blade passage and the 4-5 tip side communication part exist in the blade body. Therefore, the pressure difference in the area where the fourth blade passage, the 4-5 tip side communication part, and the fifth blade passage exist in the blade body is larger than the pressure difference in the area where the third blade passage, the 2-3 tip side communication part, and the second blade passage exist in the blade body. In this case, the flow velocity of the combustion gas passing through the 4-5 area in the tip surface is higher than the flow velocity of the combustion gas passing through the 2-3 area in the tip surface. When the flow velocity of the combustion gas is high, the heat transfer coefficient between the combustion gas and the blade body increases, so the heat transfer coefficient between the 4-5 area in the tip surface and the combustion gas is higher than the heat transfer coefficient between the 2-3 area in the tip surface and the combustion gas.

[0020] In this embodiment, the area density of the outlets of the 2-3 region nozzles that open in the 2-3 region, which has a low heat transfer coefficient on the tip surface, is reduced, while the area density of the outlets of the 4-5 region nozzles that open in the 4-5 region, which has a high heat transfer coefficient on the tip surface, is increased. As a result, in this embodiment, the amount of cooling air that is ejected from the outlets of the 2-3 region, which is relatively hard to heat on the tip surface, is reduced, and the cooling performance for the 4-5 region, which is relatively easy to heat on the tip surface, is improved. Therefore, in this embodiment, the durability of the blade can be improved while reducing the amount of cooling air used.

[0021] In order to achieve the above object, a gas turbine according to one aspect of the invention comprises: The turbine includes a rotor shaft having a plurality of the rotor blades according to the above aspect, the rotor shaft being rotatable about an axis line and having the plurality of the rotor blades attached in a line in a circumferential direction about the axis line, and a turbine casing covering the plurality of the rotor blades and an outer circumferential side of the rotor shaft. The rotor blades are attached to the rotor shaft such that the blade height direction is radial with respect to the axis line and the tip side is radially outward with respect to the axis line. Effect of the Invention

[0022] According to one aspect of the present disclosure, it is possible to increase the durability of the rotor blade while reducing the amount of cooling air used. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic cross-sectional view of a gas turbine in one embodiment according to the present disclosure. [Diagram 2] FIG. 2 is a perspective view of a blade in one embodiment according to the present disclosure. [Diagram 3] 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] 4 is a view taken along the arrow IV in FIG. 2. [Diagram 5] 5 is a cross-sectional view taken along line VV in FIG. 4. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 2 is a cross-sectional view of a main portion of a blade in a first modified example of an embodiment according to the present disclosure. [Figure 8] FIG. 11 is a view of a rotor blade according to a second modified example of an embodiment according to the present disclosure, as viewed from the radially outer side. [Figure 9] 13 illustrates a rotor blade according to a third modified example of an embodiment according to the present disclosure, as viewed from the radially outer side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0025] Gas Turbine Embodiments An embodiment of a gas turbine will be described with reference to FIG.

[0026] As shown in FIG. 1, a gas turbine 10 of this embodiment includes a compressor 20 that compresses air A, a combustor 30 that combusts 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 has a compressor rotor 21 rotating about an axis Ar, a compressor casing 25 covering the compressor rotor 21, and a plurality of stator blade rows 26. The turbine 40 has a turbine rotor 41 rotating about an axis Ar, a turbine casing 45 covering the turbine rotor 41, and a plurality of stator blade rows 46. In the following, the direction in which the axis Ar extends is referred to as the axial direction Da, the circumferential direction centered on the 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. One side of the axial direction Da is referred to as the axial upstream side Dau, and the opposite side is referred to as the axial downstream side Dad. The side of the radial direction Dr approaching the axis Ar is referred to as the radial inner side Dri, and the opposite side is referred to as the radial outer side Dro.

[0028] The compressor 20 is disposed on the axial upstream side Dau with respect 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, a 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 disposed between the compressor casing 25 and the turbine casing 45 in the axial direction Da. 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 an axial direction Da about an axis Ar, and a plurality of rotor blade rows 23 attached to the rotor shaft 22. The plurality of rotor blade rows 23 are arranged in the axial direction Da. Each of the rotor blade rows 23 is composed of a plurality of rotor blades arranged in a circumferential direction Dc. On the axial downstream side Dad of each of the plurality of rotor blade rows 23, one of the plurality of stator blade rows 26 is arranged. Each of the stator blade rows 26 is provided inside a compressor casing 25. Each of the stator blade rows 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 an axial direction Da about an axis Ar, and a plurality of rotor blade rows 43 attached to the rotor shaft 42. The plurality of rotor blade rows 43 are aligned in the axial direction Da. Each of the rotor blade rows 43 is composed of a plurality of rotor blades aligned in a circumferential direction Dc. On the axial upstream side Dau of each of the plurality of rotor blade rows, one of the plurality of stator blade rows 46 is disposed. Each of the stator blade rows 46 is provided inside a turbine casing 45. Each of the stator blade rows 46 is composed of a plurality of stator blades aligned in the circumferential direction Dc.

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

[0033] The compressor 20 compresses air A to generate compressed air. This compressed air flows into the combustor 30. Fuel F is supplied to the combustor 30. In the combustor 30, the fuel F is combusted in the compressed air to generate high-temperature, high-pressure combustion gas G. This combustion gas G is sent from the combustor 30 to an annular combustion gas flow passage 49 in a turbine casing 45. The combustion gas G rotates the turbine rotor 41 while flowing through the combustion gas flow passage 49 toward the axial downstream side Dad. The rotation of the turbine rotor 41 rotates the rotor of a generator GEN connected to the gas turbine rotor 11. As a result, the generator GEN generates electricity.

[0034] Hereinafter, an embodiment and modifications of the rotor blades constituting the rotor blade row 43 of the turbine 40 will be described.

[0035] "One embodiment of rotor blade" An embodiment of the rotor blade will be described with reference to Figs.

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

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

[0038] When this rotor blade 50 is attached to the rotor shaft 42 described above, the blade body 51 is present in the combustion gas flow path 49 described above with reference to Fig. 1. For this reason, the rotor blade 50 in this embodiment is provided 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, the blade height direction is the radial direction Dr, the tip side is the radial outside Dro, and the hub side is the radial inside Dri. The front side where the leading edge 53f exists relative to the trailing edge 53b is the axial upstream side Dau, and the rear side where the trailing edge 53b exists relative to the leading edge 53f is the axial downstream side Dad. The direction in which the positive pressure surface 54p and the negative pressure surface 54n are aligned is the circumferential direction Dc. Therefore, in the following, the blade height direction is indicated as the blade height direction Dr, the tip side is indicated as the tip side Dro, and the hub side is indicated as the hub side Dri. The front side where the leading edge 53f exists relative to the trailing edge 53b is indicated as the front side Dau, and the rear side where the trailing edge 53b exists relative to the leading edge 53f is indicated as the rear side Dad.

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

[0041] The blade root 59 is provided on the hub side Dri of the platform 58. This blade root 59 is a portion for attaching the rotor blade 50 to the rotor shaft 42. This blade root 59 has a cross-sectional shape in the shape of a Christmas tree.

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

[0043] 2 and 3, the introduction passage 61 has two introduction passage sections 62 that extend in the blade height direction Dr at least in the blade root 59 and are arranged side by side along the camber line CL of the blade body 51. Of the two introduction passage sections 62, the first introduction passage section 62a on the front side Dau and the second introduction passage section 62b on the rear side Dad both have an inlet 62i that opens in the bottom surface 59b of the blade root 59, and the cooling air Ac can flow in from this inlet 62i. The bottom surface 59b of the blade root 59 is the surface of the blade root 59 that faces the hub side Dri and is located closest to the hub side Dri.

[0044] The blade body passage 63 extends in the blade height direction Dr within the blade body 51 and has six blade body passage sections 64 aligned from the front side Dau to the rear side Dad along the camber line CL, and a communication section 65 that communicates two adjacent blade body passage sections 64 among the six blade body passage sections 64. Here, of the six blade body passage sections 64, the blade body passage section 64 located on the front side Dau is the first blade body passage section 64a, the blade body passage section 64 located on the rear side Dad of the first blade body passage section 64a and adjacent to the first blade body passage section 64a is the second blade body passage section 64b, and the blade body passage section 64 located on the rear side Dad of the second blade body passage section 64b and adjacent to the second blade body passage section 64b is the third blade body passage section 64c. Furthermore, of the six wing body passage sections 64, the wing body passage section 64 located at the rear Dad of the third wing body passage section 64c and adjacent to the third wing body passage section 64c is designated as the fourth wing body passage section 64d, the wing body passage section 64 located at the rear Dad of the fourth wing body passage section 64d and adjacent to the fourth wing body passage section 64d is designated as the fifth wing body passage section 64e, and the wing body passage section 64 located at the rearmost Dad and adjacent to the fifth wing body passage section 64e is designated as the sixth wing body passage section 64f.

[0045] The communication section 65 has 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 communicates the hub side Dri portion of the first blade passage section 64a with the hub side Dri portion of the second blade passage section 64b. The 2-3 tip side communication section 65c communicates the tip side Dro portion of the second blade passage section 64b with the tip side Dro portion of the third blade passage section 64c. The 4-5 tip side communication section 65d communicates the tip side Dro portion of the fourth blade passage section 64d with the tip side Dro portion of the fifth blade passage section 64e. The 5-6 hub side communicating portion 65e communicates the hub side Dri portion of the fifth blade passage portion 64e with the hub side Dri portion of the sixth blade passage portion 64f.

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

[0047] Each of the front holes 66 has an outlet that opens at the leading edge 53f and the area near the leading edge 53f in the blade surface 52, and can eject a part of the cooling air Ac flowing through the first blade passage 64a from this outlet. The rear holes 67 have an outlet that opens at the trailing edge 53b in the blade surface 52, and can eject a part of the cooling air Ac flowing through the sixth blade passage 64f from this outlet.

[0048] 2 to 6, each of the plurality of tip ejection holes 68 has an outlet 68o (see FIG. 2) that opens on the tip surface 55, and the cooling air Ac from the blade-body passage 63 can be ejected from this outlet 68o. The outlets 68o of each of the plurality of tip ejection holes 68 are aligned along the camber line CL from the front side Dau to the rear side Dad.

[0049] As shown in FIG. 2, FIG. 4 and FIG. 5, each of the pressure side corner nozzles 69p has an outlet that opens at the pressure side corner 56p, which is the boundary between the pressure surface 54p and the tip surface 55, and the cooling air Ac from the blade body passage 63 can be ejected from this outlet. The outlets of each of the pressure side corner nozzles 69p are aligned from the front side Dau to the rear side Dad at the pressure side corner 56p. Each of the suction side corner nozzles 69n has an outlet that opens at the suction side corner 56n, which is the boundary between the suction surface 54n and the tip surface 55, and the cooling air Ac from the blade body passage 63 can be ejected from this outlet. The outlets of each of the suction side corner nozzles 69n are aligned from the front side Dau to the rear side Dad at the suction side corner 56n.

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

[0051] The outlet 68o of the 1-region outlet 68a, which is a part of the plurality of tip outlets 68, opens in the 1-region 55a in the tip surface 55. The 1-region outlet 68a can eject the cooling air Ac that has flowed through the first blade passage 64a from this outlet 68o. The outlet 68o of the 2-3-region outlet 68c, which is another part of the plurality of tip outlets 68, opens in the 2-3 region 55c in the tip surface 55. The 2-3-region outlet 68c can eject a part of the cooling air Ac that flows through the third blade passage 64c, the 2-3 tip-side communicating portion 65c, and the second blade passage 64b from this outlet 68o. The outlet 68o of the 4-5-region outlet 68d, which is yet another part of the plurality of tip outlets 68, opens in the 4-5 region 55d in the tip surface 55. The multiple 4-5 region ejection holes 68d are capable of ejecting, from this outlet 68o, a portion of the cooling air Ac flowing through the fourth blade passage portion 64d, the 4-5 tip side communication portion 65d, and the fifth blade passage portion 64e.

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

[0053] Also, the area density, which is the number of outlets 68o of the 4-5 region orifices 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 2-3 region orifices 68c per unit area in the 2-3 region 55c. Specifically, the area density of the outlets 68o of the 4-5 region orifices 68d is at least twice but not more than ten times the area density of the outlets 68o of the 2-3 region orifices 68c. For example, the area density of the outlets 68o of the 4-5 region orifices 68d is five times the area density of the outlets 68o of the 2-3 region orifices 68c.

[0054] The cooling air Ac that has flowed into the first introduction passage 62a flows into the third blade passage 64c. This cooling air Ac flows through the third blade passage 64c to the tip side Dro, and in this process, convectively cools the area around the third blade passage 64c. The cooling air Ac that has flowed through the third blade passage 64c flows into the 2-3 tip side communicating portion 65c. This cooling air Ac flows through the 2-3 tip side communicating portion 65c to the front side Dau, and in this process, convectively cools the area around the 2-3 tip side communicating portion 65c. The cooling air Ac that has flowed through the 2-3 tip side communicating portion 65c flows into the second blade passage 64b. This cooling air Ac flows through the second blade passage 64b to the hub side Dri, and in this process, convectively cools the area around the second blade passage 64b. The cooling air Ac that has flowed through the second blade body passage portion 64b flows into the 1-2 hub side communication portion 65a. This cooling air Ac flows through the 1-2 hub side communication portion 65a to the front side Dau, and in this process, convectively cools the area around the 1-2 hub side communication portion 65a. The cooling air Ac that has flowed through the 1-2 hub side communication portion 65a flows into the first blade body passage portion 64a. This cooling air Ac flows through the first blade body passage portion 64a to the tip side Dro, and in this process, convectively cools the area around the first blade body passage portion 64a. A part of the cooling air Ac that flows through the first blade body passage portion 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, convectively cools the area around the multiple front ejection holes 66. The cooling air Ac that has flowed 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 front ejection holes 66 performs film cooling around the leading edge 53 f in the blade surface 52 .

[0055] The cooling air Ac that flows into the second introduction passage 62b flows into the fourth blade passage 64d. This cooling air Ac flows through the fourth blade passage 64d to the tip side Dro, and in this process, convectively cools the area around the fourth blade passage 64d. The cooling air Ac that flows through the fourth blade passage 64d flows into the 4-5 tip side communicating portion 65d. This cooling air Ac flows through the 4-5 tip side communicating portion 65d to the rear side Dad, and in this process, convectively cools the area around the 4-5 tip side communicating portion 65d. The cooling air Ac that flows through the 4-5 tip side communicating portion 65d flows into the fifth blade passage 64e. This cooling air Ac flows through the fifth blade passage 64e to the hub side Dri, and in this process, convectively cools the area around the fifth blade passage 64e. The cooling air Ac that has flowed through the fifth blade passage 64e flows into the 5-6 hub side communicating portion 65e. This cooling air Ac flows through the 5-6 hub side communicating portion 65e to the rear side Dad, and in this process, convection cooling is performed around the 5-6 hub side communicating portion 65e. The cooling air Ac that has flowed through the 5-6 hub side communicating portion 65e flows into the sixth blade passage 64f. This cooling air Ac flows through the sixth blade passage 64f to the tip side Dro, and in this process, convection cooling is performed around the sixth blade passage 64f. A part of the cooling air Ac that flows through the sixth blade 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, convection cooling is performed around the multiple rear ejection holes 67. The cooling air Ac that has flowed 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 ejection holes 67 performs film cooling around the trailing edge 53 b in 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 introduction passage 62a flows through the third blade passage 64c, the 2-3 tip side communicating portion 65c, the second blade passage 64b, the 1-2 hub side communicating portion 65a, and the first blade passage 64a, and is then ejected from the leading edge 53f of the blade body 51. Also, in this rotor blade 50, the cooling air Ac that flows into the second introduction passage 62b flows through the fourth blade passage 64d, the 4-5 tip side communicating portion 65d, the fifth blade passage 64e, the 5-6 hub side communicating portion 65e, and the sixth blade passage 64f, and is then ejected from the trailing edge 53b of the blade body 51. Therefore, in the rotor blade 50 of this embodiment, the rotor blade 50 can be cooled while suppressing the amount of cooling air Ac.

[0057] 4, part of the combustion gas G coming from the front side Dau toward the blade body 51 flows along the positive pressure surface 54p of the blade body 51 to the rear side Dad, and the other part flows along the negative pressure surface 54n of the blade body 51 to the rear side Dad. With the blade body 51 as a reference, 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 force in the circumferential direction Dc acts on the blade body 51 due to the pressure difference of the combustion gas G.

[0058] 5 and 6, there is a gap between the tip surface 55 of the blade body 51 and the turbine casing 45. As described above, the pressure of the combustion gas G on the pressure surface 54p side is higher than the pressure of the combustion gas G on the suction surface 54n side, so that a part of the combustion gas G on the pressure surface 54p side flows into the gap between the tip surface 55 and the turbine casing 45, and then flows out to the suction surface 54n side. Therefore, the tip surface 55 of the blade body 51 is also exposed to the high-temperature combustion gas G.

[0059] The rotor blade 50 in this embodiment has a plurality of tip ejection holes 68. A portion of the cooling air Ac flowing through the blade-body passage 63 flows into the plurality of tip ejection holes 68. This cooling air Ac convectively cools the periphery of the tip ejection hole 68 while flowing through the tip ejection hole 68. The cooling air Ac that has flowed through the plurality of tip ejection holes 68 is ejected from an outlet 68o of the tip ejection hole 68 that opens on the tip surface 55. The cooling air Ac ejected from the plurality of tip ejection holes 68 film-cools the tip surface 55.

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

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

[0062] In this embodiment, the linear density of the outlets 68o of the 2-3 region jet holes 68c opening in the 2-3 region 55c having a low heat transfer coefficient in the tip surface 55 is reduced, while the linear density of the outlets 68o of the 4-5 region jet holes 68d opening in the 4-5 region 55d having a high heat transfer coefficient in the tip surface 55 is increased. As a result, in this embodiment, the amount of cooling air Ac jetted from the outlets 68o of the 2-3 region 55c which is relatively hard to heat in the tip surface 55 is reduced, and the cooling performance for the 4-5 region 55d which is relatively easy to heat in the tip surface 55 is improved. Therefore, in this embodiment, the durability of the rotor blade 50 can be improved while reducing the amount of cooling air Ac used.

[0063] The flow of the combustion gas G at the position along the pressure side corner 56p and the flow of the combustion gas G at the position along the suction side corner 56n are disturbed. This is because the pressure side corner 56p is a position where the combustion gas G on the pressure surface 54p side flows into a narrow gap between the tip surface 55 and the turbine casing 45, and the suction side corner 56n is a position where the combustion gas G flows out from the narrow gap between the tip surface 55 and the turbine casing 45 into a wide space on the suction surface 54n side. The heat transfer coefficient between the combustion gas G and the blade body 51 is high even in the place where the flow of the combustion gas G is disturbed as described above. The rotor blade 50 in this embodiment has a pressure side corner ejection hole 69p that opens at the pressure side corner 56p where the heat transfer coefficient is relatively higher than the surrounding area, and a suction side corner ejection hole 69n that opens at the suction side corner 56n where the heat transfer coefficient is relatively higher than the surrounding area. This improves the cooling performance of the positive pressure side corners 56p and the negative pressure side corners 56n, which are more likely to heat up than the surrounding areas.

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

[0065] "First modified version of the moving wing" As shown in FIG. 7, the 4-5 region holes 68d may be inclined with respect to the tip surface 55 so as to gradually approach the rear edge 53b as they approach the tip side Dro. In this case, the length of the 4-5 region holes 68d is longer than the length of the 4-5 region holes 68d when the 4-5 region holes 68d extend in a direction perpendicular to the tip surface 55. Also, the projected area of ​​the 4-5 region holes 68d on the tip surface 55 is larger than the projected area of ​​the 4-5 region holes 68d when the 4-5 region holes 68d extend in a direction perpendicular to the tip surface 55. Therefore, in this modification, the convection cooling effect of the cooling air Ac flowing through the 4-5 region holes 68d can be applied over a wide area in the tip surface 55.

[0066] All of the plurality of tip ejection holes 68 may be inclined with respect to the tip surface 55, similar to the above modified example.

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

[0068] In the second and third modified examples, similarly to the above embodiment, the area density, which is the number of outlets 68o of the 4-5 region nozzles 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 2-3 region nozzles 68c per unit area in the 2-3 region 55c. Specifically, the area density of the outlets 68o of the 4-5 region nozzles 68d is at least two times and at most ten times the area density of the outlets 68o of the 2-3 region nozzles 68c.

[0069] "Other Modifications" The rotor blade 50 in the above embodiment 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. When 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] The present disclosure is not limited to the embodiments and modifications described above. Various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and intent of the present invention derived from the contents defined in the claims and their equivalents.

[0071] "Additional Notes" The rotor blade 50 in the above embodiment and modified examples can be understood, for example, as follows.

[0072] (1) The rotor blade 50 in the first embodiment is The blade has a cross section that forms an airfoil shape and extends in a blade height direction Dr that includes a directional component perpendicular to the cross section. The blade has a tip side Dro and a hub side Dri in the blade height direction Dr. The blade has a platform 58 provided at the end of the hub side Dri of the blade body 51, a blade root 59 provided on the hub side Dri of the platform 58, and a cooling air passage 60 formed through the blade root 59, the platform 58 and the blade body 51, through which cooling air Ac can flow. The blade body 51 has a blade surface 52 facing a direction having a directional component perpendicular to the blade height direction Dr, and a tip surface 55 facing the tip side Dro in the blade height direction Dr. The blade surface 52 has a leading edge 53f and a trailing edge 53b extending in the blade height direction Dr, and a pressure surface 54p and a suction surface 54n extending in the blade height direction Dr and expanding from the leading edge 53f to the trailing edge 53b. The cooling air passage 60 has an introduction passage 61 formed at least within the blade root 59, a blade body passage 63 formed at least within the blade body 51, and a plurality of tip outlet holes 68 having an outlet 68o opening at the tip surface 55 and capable of ejecting cooling air Ac from the outlet 68o. The introduction passage 61 has a first introduction passage portion 62a and a second introduction passage portion 62b. The first introduction passage portion 62a and the second introduction passage portion 62b each have an inlet 62i that opens on the surface of the blade root 59, and cooling air Ac can flow in from the inlet 62i. The blade body passage 63 extends in the blade height direction Dr and has six blade body passage sections 64 lined up along the camber line CL of the blade body 51 from the leading edge 53f side to the trailing edge 53b side, and a communication section 65 that connects two adjacent blade body passage sections 64 among the six blade body passage sections 64. The six wing passages 64 include a first wing passage 64a closest to the leading edge 53f, a second wing passage 64b located closer to the trailing edge 53b than the first wing passage 64a and adjacent to the first wing passage 64a, a third wing passage 64c located closer to the trailing edge 53b than the second wing passage 64b and adjacent to the second wing passage 64b, a fourth wing passage 64d located closer to the trailing edge 53b than the third wing passage 64c and adjacent to the third wing passage 64c, a fifth wing passage 64e located closer to the trailing edge 53b than the fourth wing passage 64d and adjacent to the fourth wing passage 64d, and a sixth wing passage 64f located closest to the trailing edge 53b and adjacent to the fifth wing passage 64e. The communicating portion 65 includes a 1-2 hub side communicating portion 65a that communicates the hub side Dri portion of the first blade passage portion 64a with the hub side Dri portion of the second blade passage portion 64b, a 2-3 tip side communicating portion 65c that communicates the tip side Dro portion of the second blade passage portion 64b with the tip side Dro portion of the third blade passage portion 64c, a 4-5 tip side communicating portion 65d that communicates the tip side Dro portion of the fourth blade passage portion 64d with the tip side Dro portion of the fifth blade passage portion 64e, and a 5-6 hub side communicating portion 65e that communicates the hub side Dri portion of the fifth blade passage portion 64e with the hub side Dri portion of the sixth blade passage portion 64f. The first introduction passage portion 62a communicates with the hub side Dri portion of the third blade passage portion 64c, and the second introduction passage portion 62b communicates with the hub side Dri portion of the fourth blade passage portion 64d. The tip surface 55 has a 2-3 region 55c, on the hub side Dri of the tip surface 55, in which the second blade passage portion 64b, the 2-3 tip side communicating portion 65c, and the third blade passage portion 64c are present, and a 4-5 region 55d, on the hub side Dri of the tip surface 55, in which the fourth blade passage portion 64d, the 4-5 tip side communicating portion 65d, and the fifth blade passage portion 64e are present. Of the plurality of tip holes 68, a portion of the 2-3 region holes 68c have their outlets 68o opening in the 2-3 region 55c in the tip surface 55. Of the plurality of tip holes 68, a portion of the other 4-5 region holes 68d have their outlets 68o opening in the 4-5 region 55d in the tip surface 55. The area density, which is the number of outlets 68o of the multiple 4-5 region orifices 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 orifices 68c per unit area in the 2-3 region 55c.

[0073] In the rotor blade 50 of this embodiment, the cooling air Ac that flows into the first inlet passage 62a flows through the third blade passage 64c, the 2-3 tip side communicating portion 65c, the second blade passage 64b, the 1-2 hub side communicating portion 65a, and the first blade passage 64a, and in the process of flowing through these passages and communicating portions, convection cooling is performed around these passages and communicating portions. In the rotor blade 50 of this embodiment, the cooling air Ac that flows into the second inlet passage 62b flows through the fourth blade passage 64d, the 4-5 tip side communicating portion 65d, the fifth blade passage 64e, the 5-6 hub side communicating portion 65e, and the sixth blade passage 64f, and in the process of flowing through these passages and communicating portions, convection cooling is performed around these passages and communicating portions. Therefore, in the rotor blade 50 of this embodiment, the rotor blade 50 can be cooled while suppressing the amount of cooling air Ac.

[0074] A part of the combustion gas G coming toward the blade body 51 from the leading edge 53f side flows along the pressure surface 54p of the blade body 51 to the trailing edge 53b side, and the other part flows along the suction surface 54n of the blade body 51 to the trailing edge 53b side. With respect to the blade body 51 as a reference, the pressure of the combustion gas G on the pressure surface 54p side is higher than the pressure of the combustion gas G on the suction surface 54n side. A force in the circumferential direction Dc acts on the blade body 51 due to the pressure difference of the combustion gas G. There is a gap between the tip surface 55 of the blade body 51 and the turbine casing 45. As described above, with respect to the blade body 51 as a reference, the pressure of the combustion gas G on the pressure surface 54p side is higher than the pressure of the combustion gas G on the suction surface 54n side, so that a part of the combustion gas G on the pressure surface 54p side flows into the gap between the tip surface 55 and the turbine casing 45 and then flows out to the suction surface 54n side. Therefore, the tip surface 55 of the blade body 51 is also exposed to the high-temperature combustion gas G.

[0075] The rotor blade 50 in this embodiment has a plurality of tip ejection holes 68. A portion of the cooling air Ac flowing through the blade-body passage 63 flows into the plurality of tip ejection holes 68. This cooling air Ac convectively cools the periphery of the tip ejection hole 68 while flowing through the tip ejection hole 68. The cooling air Ac that has flowed through the plurality of tip ejection holes 68 is ejected from an outlet 68o of the tip ejection hole 68 that opens on the tip surface 55. The cooling air Ac ejected from the plurality of tip ejection holes 68 film-cools the tip surface 55.

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

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

[0078] In this embodiment, the area density of the outlets 68o of the 2-3 region ejection holes 68c opening in the 2-3 region 55c having a low heat transfer coefficient in the tip surface 55 is reduced, while the area density of the outlets 68o of the 4-5 region ejection holes 68d opening in the 4-5 region 55d having a high heat transfer coefficient in the tip surface 55 is increased. As a result, in this embodiment, the amount of cooling air Ac ejected from the outlets 68o of the 2-3 region 55c which is relatively hard to heat in the tip surface 55 is reduced, and the cooling performance for the 4-5 region 55d which is relatively easy to heat in the tip surface 55 is improved. Therefore, in this embodiment, the durability of the rotor blade 50 can be improved while reducing the amount of cooling air Ac used.

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

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

[0081] (4) The rotor blade 50 in the fourth embodiment is In the rotor blade 50 according to any one of the first to third aspects, The outlets 68o of each of the plurality of tip jet 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 the outlets 68o in the plurality of tip jet holes 68 per unit length of the camber line CL is defined as a linear density, the linear density of the outlets 68o in the plurality of 4-5 region jet holes 68d is higher than the linear density of the outlets 68o in the plurality of 2-3 region jet holes 68c.

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

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

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

[0085] (7) The rotor blade 50 in the seventh embodiment is In the rotor blade 50 in the sixth embodiment, the linear density of the outlets 68o in the plurality of 4-5 region holes 68d is 2.5 times or less than the linear density of the outlets 68o in the plurality of 2-3 region 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 4-5 region holes 68d among the plurality of tip holes 68 are inclined with respect to the tip surface 55 so as to 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 the multiple 4-5 region ejection holes 68d extend in a direction perpendicular to the tip surface 55. In addition, in this embodiment, the projected area of ​​the multiple 4-5 region ejection holes 68d on the tip surface 55 is larger than the projected area of ​​the multiple 4-5 region ejection holes 68d when the multiple 4-5 region ejection holes 68d extend in a direction perpendicular to the tip surface 55. Therefore, in this embodiment, the convection cooling effect by the cooling air Ac flowing through the multiple 4-5 region ejection holes 68d can be applied over a wide area in the tip surface 55.

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

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

[0090] (10) In a tenth aspect, the rotor blade 50 has 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 a suction side corner 56n, which is the boundary between the suction surface 54n and the tip surface 55, and has a plurality of suction side corner outlet holes 69n arranged from the leading edge 53f side to the trailing edge 53b side so as to be able to eject the cooling air Ac from the blade-body passage 63 from the outlet of the suction side corner 56n.

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

[0092] The gas turbine 10 in the above embodiment and modified examples can be understood, for example, as follows. (11) In an eleventh aspect, the gas turbine 10 comprises: The turbine turbine includes a rotor shaft 42 having a plurality of rotor blades 50 according to any one of the first to tenth embodiments, rotatable about an axis Ar, and having the plurality of rotor blades 50 attached in a line in a circumferential direction Dc relative to the axis Ar, and a turbine casing 45 covering the plurality of rotor blades 50 and an outer circumferential side of the rotor shaft 42. The rotor blades 50 are attached to the rotor shaft 42 such that the blade height direction Dr is radial to the axis Ar and the tip side Dro is radially outward relative 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 blade row 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 connection 65c: 2-3 Tip side connection 65d: 4-5 Tip side connection 65e: 5-6 hub side connection 66: Front vent 67: Post-spout hole 68: Tip nozzle 68o:Exit 68a:1 area vent 68c:2-3 area vent 68d:4-5 area vent 69n: Negative pressure side corner nozzle 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 axis) Dc: Circumferential direction Dr: Blade height direction (or radial direction) Dri: Hub side (or radially inner side) Dro: Tip side (or radial outer side)

Claims

1. A wing body having a cross section that forms an airfoil shape and extends in a wing height direction that includes a directional component perpendicular to the cross section; a platform provided at an end of the blade body on the hub side among a tip side and a hub side in the blade height direction; A blade root provided on the hub side of the platform; a cooling air passage formed through the blade root, the platform and the blade 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 blade surface has a leading edge and a trailing edge extending in the blade height direction, and a pressure side and a suction side extending in the blade height direction and expanding from the leading edge to the trailing edge, The cooling air passage includes: an introduction passage formed at least in the blade root; a wing body passage formed within at least the wing body; a plurality of tip nozzles each having an outlet that opens on the tip surface and capable of ejecting cooling air from the outlet, The introduction passage has a first introduction passage portion and a second introduction passage portion, each of the first introduction passage portion and the second introduction passage portion has an inlet that opens on a surface of the blade root, and cooling air can flow in from the inlet; The blade passage has six blade passage sections extending in the blade height direction and arranged along a camber line of the blade from the leading edge side to the trailing edge side, and a communication section that communicates two adjacent blade passage sections among the six blade passage sections, The six wing passage sections include a first wing passage section closest to the leading edge, a second wing passage section located closer to the trailing edge than the first wing passage section and adjacent to the first wing passage section, a third wing passage section located closer to the trailing edge than the second wing passage section and adjacent to the second wing passage section, a fourth wing passage section located closer to the trailing edge than the third wing passage section and adjacent to the third wing passage section, a fifth wing passage section located closer to the trailing edge than the fourth wing passage section and adjacent to the fourth wing passage section, and a sixth wing passage section located closest to the trailing edge and adjacent to the fifth wing passage section, The communication portion is a 1-2 hub side communicating portion that communicates a hub side portion of the first blade body passage portion with a hub side portion of the second blade body passage portion; a 2-3 tip side communicating portion that communicates the tip side portion of the second blade body passage portion with the tip side portion of the third blade body passage portion; a 4-5 tip side communicating portion that communicates the tip side portion of the fourth blade passage portion with the tip side portion of the fifth blade passage portion; a 5-6 hub side communicating portion that communicates a hub side portion of the fifth blade passage portion with a hub side portion of the sixth blade passage portion; having the first inlet passage portion communicates with a hub-side portion of the third blade passage portion, and the second inlet passage portion communicates with a hub-side portion of the fourth blade passage portion, the tip surface has a 2-3 region on the hub side of the tip surface, in which the second blade passage portion, the 2-3 tip side communicating portion, and the third blade passage portion are present, and a 4-5 region on the hub side of the tip surface, in which the fourth blade passage portion, the 4-5 tip side communicating portion, and the fifth blade passage portion are present; Among the plurality of tip nozzle holes, a portion of the plurality of 2-3 region nozzle holes has an outlet that opens in the 2-3 region in the tip surface, Among the plurality of tip nozzles, the outlets of the other plurality of 4-5 region nozzles are opened in the 4-5 region in the tip surface, an areal density, which is the number of outlets in the plurality of 4-5 region orifices per unit area in the 4-5 region, is higher than an areal density, which is the number of outlets in the plurality of 2-3 region orifices per unit area in the 2-3 region; Moving blade.

2. The rotor blade according to claim 1 , the area density of the outlets in the plurality of 4-5 region orifices is equal to or greater than twice the area density of the outlets in the plurality of 2-3 region orifices; Moving blade.

3. The rotor blade according to claim 2, The area density of the outlets in the plurality of 4-5 region orifices is 10 times or less than the area density of the outlets in the plurality of 2-3 region orifices. Moving blade.

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

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

6. The rotor blade according to claim 4, The linear density of the outlets in the plurality of 4-5 region orifices is 1.5 times or more than the linear density of the outlets in the plurality of 2-3 region orifices. Moving blade.

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

8. The rotor blade according to any one of claims 1 to 3, Among the plurality of tip nozzles, at least the plurality of 4-5 region nozzles are inclined with respect to the tip surface so as to gradually approach the trailing edge side as they approach the tip side. Moving blade.

9. The rotor blade according to any one of claims 1 to 3, the cooling air passage has an outlet opening at a pressure side corner which is a boundary between the pressure surface and the tip surface, and has a plurality of pressure side corner outlet holes arranged from the leading edge side to the trailing edge side and capable of ejecting the cooling air from the blade-body passage from the outlet at the pressure side corner. Moving blade.

10. The rotor blade according to any one of claims 1 to 3, the cooling air passage has an outlet opening at a suction side corner portion which is a boundary portion between the suction surface and the tip surface, and has a plurality of suction side corner outlet holes arranged from the leading edge side to the trailing edge side and capable of ejecting the cooling air from the blade body passage from the outlet at the suction side corner portion. Moving blade.

11. A rotor blade according to any one of claims 1 to 3, a rotor shaft rotatable about an axis line, the rotor shaft having a plurality of rotor blades attached to the rotor shaft in a circumferential direction relative to the axis line; a turbine casing covering the rotor blades and an outer circumferential side of the rotor shaft; Equipped with The rotor blade is attached to the rotor shaft such that the blade height direction is a radial direction with respect to the axis line and the tip side is a radial outer side with respect to the axis line. Gas turbine.

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