Rotor blade and gas turbine equipped with same

Abstract

To enhance durability of a rotor blade while suppressing a use amount of cooling air.SOLUTION: A cooling air passage of a rotor blade includes: a main passage into which cooling air can flow; a plurality of front jetting holes capable of jetting the cooling air from a front edge periphery part which is a portion facing the front side in a blade surface; and a plurality of film holes having a blade surface jetting port opening on a negative pressure surface of a blade body, and capable of jetting the cooling air from the blade surface jetting port along the blade surface. The main passage has three or more odd number of in-blade passages extending in the blade height direction in the blade body. The plurality of front jetting holes communicate with a first in-blade passage on the frontmost side out of the odd number of in-blade passages. The plurality of film holes communicate with a second in-blade passage adjacent to the first in-blade passage out of the odd number of in-blade passages. With the central position in the blade height direction in the blade body being a reference, a ratio of an opening which is an area of the blade surface jetting port per unit area on the hub side is higher than an opening ratio which is an area of the blade surface jetting port per unit area on the tip side.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a rotor blade and a gas turbine equipped with 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 multiple stator blade rows. The turbine rotor has a rotor shaft centered on the axis and multiple rotor blade rows attached to the rotor shaft. The multiple rotor blade rows are aligned in the axial direction along which the axis extends. Each rotor blade row has multiple rotor blades aligned in the circumferential direction about the axis. The multiple stator blade rows are aligned in the axial direction and attached to the inner peripheral side of the turbine casing. Each of the multiple stator blade rows is arranged axially upstream of one of the multiple rotor blade rows. Each stator blade row has multiple 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 located radially inside the blade body. Side edge The blade root is provided radially inward of the platform. This blade root is the part where the blade is attached 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 Patent Document 1 below has a stationary blade with two cooling air passages formed in its blade body through which cooling air can flow. Each of the two cooling air passages has a main passage having an inlet opening at the surface of the blade root through which cooling air can flow, and multiple end holes through which the cooling air passing through the main passage can be ejected from the end of the blade body. Each main passage has an introduction passage section extending from the inlet at the blade root to the boundary between the platform and the blade body, and a blade body cooling passage section having three in-blade passages extending radially within the blade body. The three in-blade passages are aligned along the camber line of the blade body. Adjacent in-blade passages among the three in-blade passages communicate with each other at one of their radially inner and outer ends so that the blade body cooling passage section radially undulates to form a single serpentine passage. Of the two cooling air passages, the first cooling air passage is located at the front side of the blade body, and the second cooling air passage is located at the rear side of the blade body. Of the three in-blade passages in the first cooling air passage, the forwardmost in-blade passage is in communication with the plurality of front injection holes as the aforementioned plurality of end holes. The plurality of front injection holes open in the blade surface around the leading edge including the leading edge. Furthermore, of the three in-blade passages in the second cooling air passage, the rearmost in-blade passage is in communication with the plurality of rear injection holes as the aforementioned plurality of end holes. The plurality of rear injection holes open at the trailing edge of the blade body. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-001633 Summary of the Invention [Problem to be solved by the invention]

[0007] Gas turbine rotor blades are exposed to high-temperature combustion gases and are required to have high durability while reducing the amount of cooling air used.

[0008] Therefore, an object of the present disclosure is 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]

[0009] 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 including a directional component perpendicular to the cross section; The blade body has a platform provided at the end of the blade body on the hub side, a blade root provided on the hub side of the platform, and a cooling air passage formed through 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 from the leading edge to the trailing edge. The cooling air passage has a main passage having an inlet opening at the surface of the blade root and allowing cooling air to flow in, and a forward jet opening at a leading edge surrounding portion that includes the leading edge and faces forward relative to the trailing edge, The blade extends in a direction in which a component parallel to a normal to the blade surface at the position of the front jet port is greater than a component parallel to a tangent to the blade surface at the position of the front jet port, a plurality of front injection holes capable of ejecting the cooling air that has passed through the main passage from the front injection port; and a blade surface injection port that is open on the blade surface except for the leading edge surrounding portion and on at least one of the pressure surface and the suction surface, The blade surface extends in a direction in which a component parallel to a tangent to the blade surface at the position of the blade surface outlet is greater than a component parallel to a normal to the blade surface at the position of the blade surface outlet, and in a direction toward the trailing edge,The blade cooling system has a plurality of film holes that allow cooling air that has passed through the main passage to be ejected from the blade surface outlet along at least one of the blade surfaces to the outside. The main passage has an introduction passage section that extends from the inlet to the boundary between the platform and the blade body, and a blade-body cooling passage section that has an odd number of three or more in-blade passages extending in the blade height direction within the blade body. The odd number of in-blade passages are aligned forward from the introduction passage section along the camber line of the blade body. Adjacent in-blade passages among the odd number of in-blade passages communicate with each other at one of the hub-side end and the tip-side end so that the blade-body cooling passage section forms a single serpentine passage that undulates in the blade height direction. The plurality of front injection holes communicate with the first in-blade passage, which is the most forward of the odd number of in-blade passages. The film holes are connected to at least one of the odd number of intra-blade passages, i.e., the first intra-blade passage and the second intra-blade passage adjacent to the first intra-blade passage. With reference to the central position of the blade body in the blade height direction, the opening ratio, which is the area of ​​the blade surface outlets per unit area on the hub side, is higher than the opening ratio, which is the area of ​​the blade surface outlets per unit area on the tip side.

[0010] In this aspect, cooling air flowing into the main passage from the main passage inlet in the cooling air passage passes through the introduction passage portion of the main passage and flows into the blade-body cooling passage portion of the main passage. As the cooling air flows through three or more odd number of in-blade passages in this blade-body cooling passage portion, it convectively cools the periphery of each in-blade passage. A portion of the cooling air flowing through three or more odd number of in-blade passages is ejected to the outside from multiple film holes along the pressure surface or suction surface. As this portion of the cooling air flows through the multiple film holes, it convectively cools the periphery of the film holes. Furthermore, the cooling air ejected from the multiple film holes film cools the pressure surface or suction surface. A portion of the cooling air flowing into the first in-blade passage, which is the most forward of the three or more odd number of in-blade passages and located downstream of the cooling air flow, is ejected to the outside from multiple front injection holes. As this portion of the cooling air flows through the multiple front injection holes, it convectively cools the periphery of the front injection holes. Furthermore, the cooling air ejected from the plurality of front injection holes prevents the high-temperature combustion gas from directly impinging on the area around the leading edge, which is part of the blade surface.

[0011] The blade width, which is the distance between the pressure surface and the suction surface, gradually increases from the tip side to the hub side of the blade body. The distance between the inner surface of the blade passage and the blade surface is within a predetermined range from the viewpoint of cooling the blade surface. Accordingly, the width of the multiple blade passages extending in the blade height direction also gradually increases from the tip side to the hub side of the blade body. If the width of the blade passage gradually increases from the tip side to the hub side of the blade body, the flow velocity of the cooling air flowing through this blade passage is lower on the hub side than on the tip side. Therefore, the heat transfer coefficient between the cooling air flowing through the hub-side portion of the blade passage and the blade body is lower than the heat transfer coefficient between the cooling air flowing through the tip-side portion of the blade passage and the blade body. Therefore, the convective cooling effect of the cooling air flowing through the blade passage is lower on the hub side of the blade body.

[0012] Therefore, in this embodiment, the opening ratio, which is the area of ​​the blade surface outlet per unit area on the hub side, is set higher than the opening ratio, which is the area of ​​the blade surface outlet per unit area on the tip side, with the central position of the blade body in the blade height direction as the reference, to improve the film cooling effect on the hub side, Wing durability It increases durability.

[0013] In this embodiment, the cooling air flowing into the multiple film holes is cooling air that has flowed from the rearmost intra-blade passage among the three or more odd number of intra-blade passages to at least the downstream portion of the second intra-blade passage and has already been heated to a certain extent. Here, the downstream side refers to the downstream side of the cooling air flow. In this embodiment, the cooling air that has been heated to a certain extent and has a reduced convective cooling effect is used as film cooling air, thereby preventing waste of cold cooling air and enabling efficient cooling of the blade surface. In this embodiment, the cooling air flowing into the multiple front injection holes is cooling air that has flowed from the rearmost intra-blade passage among the three or more odd number of intra-blade passages to the first intra-blade passage and has already been heated to a certain extent. Here, the upstream side refers to the downstream side of the cooling air flow. In this embodiment, the cooling air that has been heated to a certain extent and has a reduced convective cooling effect is used as cooling air for cooling the leading edge area, which is a portion of the blade surface, preventing waste of cold cooling air and enabling efficient cooling of the blade surface.

[0014] Therefore, in this aspect, it is possible to increase the durability of the rotor blade while reducing the amount of cooling air used.

[0015] 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 one aspect, the rotor shaft being rotatable about an axis and having the plurality of rotor blades attached in a line in a circumferential direction about the axis, and a turbine casing covering the plurality of rotor blades and an outer circumferential side of the rotor shaft. The rotor blades have a blade height direction that is a radial direction about the axis, and the hub side is located in the radial direction between a radially inner side and a radially outer side about the axis. Inward The rotor shaft is attached to the rotor shaft such that the front side is on the upstream side of the upstream side and the downstream side in the axial direction in which the axis extends. [Effects of the Invention]

[0016] 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 explanation of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view of a gas turbine in one embodiment according to the present disclosure. [Figure 2] FIG. 1 is a perspective view of a rotor blade in a first embodiment according to the present disclosure. [Figure 3] FIG. 2 is a side view of the rotor blade in the first embodiment according to the present disclosure (a side view of the rotor blade as seen from the suction surface side). [Figure 4] FIG. 2 is a cross-sectional view of a rotor blade in the first embodiment according to the present disclosure. [Figure 5] FIG. 4 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 10 is a side view of a rotor blade in a second embodiment according to the present disclosure (a side view of the rotor blade as viewed from the suction surface side). [Figure 8] FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. [Figure 9] FIG. 10 is a side view of a rotor blade in a third embodiment according to the present disclosure (a side view of the rotor blade as seen from the pressure surface side). [Figure 10] 10 is a cross-sectional view taken along the line XX in FIG. 9. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, the present disclosure moving blade , and this moving blade An embodiment of a gas turbine including the above will be described in detail with reference to the drawings.

[0019] Gas Turbine Embodiment An embodiment of a gas turbine will be described with reference to FIG.

[0020] As shown in FIG. 1, the gas turbine 10 of this 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.

[0021] The compressor 20 has a compressor rotor 21 that rotates about an axis Ar, a compressor casing 25 that covers the compressor rotor 21, and a plurality of stator blade rows 26. The turbine 40 has a turbine rotor 41 that rotates about the axis Ar, a turbine casing 45 that covers the turbine rotor 41, and a plurality of stator blade rows 46. Note that, hereinafter, the direction in which the axis Ar extends will be referred to as the axial direction Da, the circumferential direction about the axis Ar will be simply referred to as the circumferential direction Dc, and the direction perpendicular to the axis Ar will be referred to as the radial direction Dr. Furthermore, one side of the axial direction Da will be referred to as the axial upstream side Dau, and the opposite side will be referred to as the axial downstream side Dad. Furthermore, the side of the radial direction Dr that approaches the axis Ar will be referred to as the radially inner side Dri, and the opposite side will be referred to as the radially outer side Dro.

[0022] The compressor 20 is disposed on the axial upstream side Dau with respect to the turbine 40 .

[0023] The compressor rotor 21 and the turbine rotor 41 are located on the same axis Ar and are connected to each other to form the gas turbine rotor 11. To this gas turbine rotor 11, for example, a rotor of a generator GEN is connected. 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 the gas turbine casing 15.

[0024] The compressor rotor 21 has a rotor shaft 22 extending in the axial direction Da around the axis Ar, and a plurality of rotor blade rows 23 attached to the rotor shaft 22. The plurality of rotor blade rows 23 are aligned in the axial direction Da. Each rotor blade row 23 is made up of a plurality of rotor blades aligned in the circumferential direction Dc. One of the plurality of stator blade rows 26 is arranged on the axial downstream side Dad of each of the plurality of rotor blade rows 23. Each stator blade row 26 is provided inside the compressor casing 25. Each stator blade row 26 is made up of a plurality of stator blades aligned in the circumferential direction Dc.

[0025] The turbine rotor 41 has a rotor shaft 42 that extends in the axial direction Da centered on the axis Ar, and a plurality of rotor blade rows 43 attached to the rotor shaft 42. The plurality of rotor blade rows 43 are aligned in the axial direction Da. Each rotor blade row 43 is made up of a plurality of rotor blades aligned in the circumferential direction Dc. Column 43 On each axial upstream side Dau, one of the plurality of stator blade rows 46 is arranged. Each stator blade row 46 is provided inside the turbine casing 45. Each stator blade row 46 is made up of a plurality of stator blades arranged in the circumferential direction Dc.

[0026] The combustor 30 is attached to the intermediate casing 14 .

[0027] 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 burned 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 path 49 in the turbine casing 45. The combustion gas G rotates the turbine rotor 41 while flowing through the combustion gas flow path 49 toward the axial downstream side Dad. The rotation of this 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.

[0028] Hereinafter, an embodiment and modifications thereof relating to the rotor blades that constitute the rotor blade row 43 in the first stage of the turbine 40 will be described.

[0029] "First embodiment of rotor blade" A first embodiment of the rotor blade will be described with reference to FIGS.

[0030] As shown in FIGS. 2 and 3, the rotor blade 50 in this embodiment includes a blade body 51, a platform 58, a blade root 59, a first cooling air passage 60, and a second cooling air passage 80.

[0031] The blade body 51 has an airfoil-shaped cross section and extends in a blade height direction Dh, which includes a directional component perpendicular to the cross section. The blade body 51 has a blade surface 52 facing a direction having a directional component perpendicular to the blade height direction Dh, and a tip surface 55 facing the tip side Dht, which is one of the tip side Dht and the hub side Dhh in the blade height direction Dh. The blade surface 52 has a leading edge 53f and a trailing edge 53b extending in the blade height direction Dh, 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.

[0032] When this rotor blade 50 is attached to the rotor shaft 42, the blade height direction Dh becomes the radial direction Dr, the tip side Dht becomes the radially outer side Dro, and the hub side Dhh becomes the radially inner side Dri. Furthermore, the front side Df, where the leading edge 53f exists relative to the trailing edge 53b, becomes the axially upstream side Dau, and the rear side Db, where the trailing edge 53b exists relative to the leading edge 53f, becomes the axially downstream side Dad. Furthermore, the direction in which the pressure surface 54p and the suction surface 54n are aligned becomes the circumferential direction Dc. When this rotor blade 50 is attached to the rotor shaft 42, the blade body 51 is positioned in the combustion gas flow path 49.

[0033] The platform 58 is provided on the hub side Dhh of the blade body 51. The platform 58 is a square plate-shaped member that extends in a direction including a directional component perpendicular to the radial direction Dr, which is the blade height direction Dh.

[0034] The blade root 59 is provided on the hub side Dhh of the platform 58. This blade root 59 is a portion for attaching the rotor blade 50 to the rotor shaft 42. The blade root 59 has a cross section shaped like a Christmas tree.

[0035] The first cooling air passage 60 and the second cooling air passage 80 are both formed through the blade root 59, the platform 58 and the blade body 51, and are passages through which cooling air Ac can flow. The second cooling air passage 80 is arranged in the rotor blade 50 on the rear side Db of the first cooling air passage 60.

[0036] The first cooling air passage 60 has a main passage 61, a tip hole 71, a plurality of front injection holes 72, and a plurality of film holes 74. The main passage 61 opens to the bottom surface 59b of the blade root 59 and has an inlet 63 through which cooling air Ac from the rotor shaft 42 can flow in. The bottom surface 59b of the blade root 59 is the surface of the blade root 59 that is located closest to the hub side Dhh and faces the hub side Dhh. The main passage 61 has an introduction passage section 62 that extends from the inlet 63 in the blade height direction Dh to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage section 65 that has three intra-blade passages 66 extending in the blade height direction Dh within the blade body 51.

[0037] The three in-blade passages 66 are lined up from the introduction passage section 62 to the forward side Df along the camber line CL of the blade body 51. Of the three in-blade passages 66, the one closest to the forward side Df is referred to as the first in-blade passage 66a, the one adjacent to the first in-blade passage 66a is referred to as the second in-blade passage 66b, and the one closest to the rearward side Db and adjacent to the second in-blade passage 66b is referred to as the third in-blade passage 66c. The third in-blade passage 66c extends from the introduction passage section 62 in the blade height direction Dh.

[0038] The blade-body cooling passage section 65 has three in-blade passages 66. Adjacent in-blade passages 66 communicate with each other at one of their hub-side Dhh and tip-side Dht ends so that the passage forms a serpentine passage undulating in the blade height direction Dh. Specifically, the tip-side Dht end of the third in-blade passage 66c communicates with the tip-side Dht end of the second in-blade passage 66b, and the hub-side Dhh end of the second in-blade passage 66b communicates with the hub-side Dhh end of the first in-blade passage 66a.

[0039] The tip hole 71 communicates with the end of the tip side Dht of the first intra-blade passage 66a and opens at the tip surface 55.

[0040] Each of the front jet holes 72 has a front jet outlet 73 that opens in the leading edge around portion 56 of the blade surface 52, which is a portion that includes the leading edge 53f and faces the forward side Df. The leading edge around portion 56 is a portion of the blade surface 52 that includes a range from the leading edge 53f along the pressure surface 54p to a predetermined distance toward the rear side Db, and a range from the leading edge 53f along the suction surface 54n to a predetermined distance toward the rear side Db. Here, the predetermined distance is, for example, 1 / 20 of the distance from the leading edge 53f to the trailing edge 53b along the pressure surface 54p (or suction surface 54n). Each of the front jet holes 72 communicates with the first intra-blade passage 66a, extends from the first intra-blade passage 66a in a predetermined direction, and opens in the leading edge around portion 56 of the blade surface 52. Here, the specified direction is a direction in which the component parallel to the normal to the blade surface 52 at the position of the front nozzle 73 is greater than the component parallel to the tangent to the blade surface 52 at the position of the front nozzle 73.

[0041] The front jet ports 73 for each of the plurality of front jet holes 72 are formed from the hub side Dhh to the tip side Dht in the leading edge around portion 56. However, with reference to the central position in the leading edge around portion 56 in the blade height direction Dh, the opening ratio, which is the area of ​​the front jet ports 73 per unit area in the tip side Dht portion, is higher than the opening ratio, which is the area of ​​the front jet ports 73 per unit area in the hub side Dhh portion. Specifically, in this embodiment, with reference to the central position in the leading edge around portion 56 in the blade height direction Dh, the number of front jet ports 73 on the tip side Dht is greater than the number of front jet ports 73 on the hub side Dhh.

[0042] Each of the multiple film holes 74 has a blade surface outlet 75 that opens in the blade surface 52, excluding the leading edge surrounding portion 56, and on at least one of the pressure surface 54p and suction surface 54n. Each of the multiple film holes 74 communicates with at least one of the three intra-blade passages 66, extends from this intra-blade passage 66 in a predetermined direction, and opens on at least one of the aforementioned blade surfaces 52. Here, the predetermined direction is a direction in which the component parallel to the tangent to the blade surface 52 at the position of the blade surface outlet 75 is greater than the component parallel to the normal to the blade surface 52 at the position of the blade surface outlet 75, and is a direction toward the rear side Db. Note that the multiple film holes 74 in this embodiment communicate with the second intra-blade passage 66b, and each of the blade surface outlets 75 opens only on the suction surface 54n.

[0043] With reference to the central position in the blade height direction Dh of at least one of the blade surfaces 52, the aperture ratio, which is the area of ​​the blade surface outlets 75 per unit area in the hub-side Dhh portion, is higher than the aperture ratio, which is the area of ​​the blade surface outlets 75 per unit area in the tip-side Dht portion. Specifically, in this embodiment, with reference to the central position in the blade height direction Dh of at least one of the blade surfaces 52, the number of the blade surface outlets 75 in the hub-side Dhh portion is greater than the number of the blade surface outlets 75 in the tip-side Dht portion. More specifically, in this embodiment, a plurality of blade surface outlets 75 are formed only in the hub-side Dhh portion, and no blade surface outlets 75 are formed in the tip-side Dht portion. Note that, as long as the number of blade surface outlets 75 is greater on the hub-side Dhh than on the tip-side Dht with reference to the central position in the blade height direction Dh of at least one of the blade surfaces 52, the blade surface outlets 75 may be formed on the tip-side Dht.

[0044] The second cooling air passage 80 has a main passage 81 and a plurality of rear injection holes 88. The main passage 81 opens at the bottom surface 59b of the blade root 59 and has an inlet 83 through which cooling air Ac from the rotor shaft 42 can flow in. The inlet 83 of the main passage 81 in this second cooling air passage 80 is formed on the rear side Db of the inlet 63 of the main passage 61 in the first cooling air passage 60. The main passage 81 has an introduction passage section 82 extending from the inlet 83 in the blade height direction Dh to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage section 85 having three intra-blade passages 86 extending in the blade height direction Dh within the blade body 51.

[0045] The three in-blade passages 86 are lined up from the introduction passage section 82 to the rear side Db along the camber line CL of the blade body 51. Of the three in-blade passages 86, the one closest to the front side Df is referred to as the fourth in-blade passage 86a, the one adjacent to the fourth in-blade passage 86a is referred to as the fifth in-blade passage 86b, and the one closest to the rear side Db and adjacent to the fifth in-blade passage 86b is referred to as the sixth in-blade passage 86c. The fourth in-blade passage 86a extends from the introduction passage section 82 in the blade height direction Dh.

[0046] The blade-body cooling passage section 85 has three in-blade passages 86, and adjacent in-blade passages 86 communicate with each other at one of their hub-side Dhh ends and tip-side Dht ends so as to form a single serpentine passage that undulates in the blade height direction Dh. Specifically, the tip-side Dht end of the fourth in-blade passage 86a communicates with the tip-side Dht end of the fifth in-blade passage 86b, and the hub-side Dhh end of the fifth in-blade passage 86b communicates with the hub-side Dhh end of the sixth in-blade passage 86c.

[0047] Each of the multiple rear ejection holes 88 has a rear ejection port 89 that opens at the trailing edge 53 b. The multiple rear ejection holes 88 are aligned in the blade height direction Dh. Each of the multiple rear ejection holes 88 communicates with the sixth intra-blade passage 86 c, in other words, the rearmost intra-blade passage 86 c, which is located on the rearmost side Db among the multiple intra-blade passages 86 in the second cooling air passage 80, and extends from this rearmost intra-blade passage 86 c to the trailing edge 53 b.

[0048] Although the number of in-blade passages 86 in the second cooling air passage 80 in this embodiment is three, it may be two, four or more. Furthermore, when the number of in-blade passages 86 in the second cooling air passage 80 is an odd number as in this embodiment, the second cooling air passage 80 may have a tip hole that communicates with the end of the tip side Dht of the rearmost in-blade passage 86c (sixth in-blade passage 86c) and opens at the tip surface 55. Furthermore, the second cooling air passage 80 may have a tip hole that communicates with the end of the tip side Dht of the rearmost in-blade passage 86c (sixth in-blade passage 86c) Those Wings A plurality of film holes may be provided which communicate with the inner passage 86 and open on the positive pressure surface 54p or the negative pressure surface 54n.

[0049] In this embodiment, the cooling air Ac that flows into the main passage 61 from the inlet 63 of the main passage 61 in the first cooling air passage 60 passes through the introduction passage portion 62 of the main passage 61 and flows into the blade-body cooling passage portion 65 of the main passage 61. As the cooling air Ac flows through the three in-blade passages 66 in this blade-body cooling passage portion 65, it convectively cools the periphery of each in-blade passage 66. A portion of the cooling air Ac flowing through the three in-blade passages 66 is ejected to the outside from the multiple film holes 74 along the pressure side 54p or the suction side 54n. As this cooling air Ac flows through the multiple film holes 74, it convectively cools the periphery of the film holes 74. Furthermore, the cooling air Ac ejected from the multiple film holes 74 film-cools the pressure side 54p or the suction side 54n. Of the three in-blade passages 66, a portion of the cooling air Ac that flows into the first in-blade passage 66a, which is located at the most forward side Df and downstream of the flow of the cooling air Ac, is ejected to the outside from the multiple front injection holes 72. As this portion of the cooling air Ac flows through the multiple front injection holes 72, it convectively cools the areas around the front injection holes 72. Furthermore, the cooling air Ac ejected from the multiple front injection holes 72 prevents high-temperature combustion gas from directly impinging on the leading edge surrounding portion 56, which is part of the blade surface 52. Furthermore, the remainder of the cooling air Ac that flows into the first in-blade passage 66a is ejected to the outside from the tip ejection hole 71.

[0050] In this embodiment, the cooling air Ac that flows into the main passage 81 from the inlet 83 of the main passage 81 in the second cooling air passage 80 passes through the introduction passage portion 82 of the main passage 81 and flows into the blade-body cooling passage portion 85 of the main passage 81. As the cooling air Ac flows through the three in-blade passages 86 in the blade-body cooling passage portion 85, it convectively cools the periphery of each in-blade passage 86. A portion of the cooling air Ac flowing through the three in-blade passages 86 is ejected to the outside from a sixth in-blade passage (rearmost in-blade passage) 86c, which is located at the rearmost side Db of the three in-blade passages 86 and downstream of the flow of the cooling air Ac, through a plurality of rear ejection holes 88. As the cooling air Ac flows through the plurality of rear ejection holes 88, it convectively cools the periphery of the rear ejection holes 88. Furthermore, the cooling air Ac ejected from the plurality of rear ejection holes 88 suppresses the generation of a wake of combustion gas on the rear side Db of the trailing edge 53b.

[0051] Incidentally, the blade width, which is the distance between the pressure surface 54p and the suction surface 54n, gradually increases from the tip side Dht to the hub side Dhh of the blade body 51. Furthermore, the distance between the inner surface of the in-blade passage 66 and the blade surface 52 is within a predetermined range from the viewpoint of cooling the blade surface 52. Accordingly, as shown in FIGS. 5 and 6, the width of the multiple in-blade passages 66 extending in the blade height direction Dh also gradually increases from the tip side Dht to the hub side Dhh of the blade body 51. If the width of the in-blade passage 66 gradually increases from the tip side Dht to the hub side Dhh of the blade body 51, the flow velocity of the cooling air Ac flowing through the in-blade passage 66 becomes lower on the hub side Dhh than on the tip side Dht. For this reason, the heat transfer coefficient between the cooling air Ac flowing in the hub side Dhh portion of the in-blade passage 66 and the blade body 51 is lower than the heat transfer coefficient between the cooling air Ac flowing in the tip side Dht portion of the in-blade passage 66 and the blade body 51. Therefore, the convective cooling effect of the cooling air Ac flowing through the in-blade passage 66 is lower in the hub side Dhh portion of the blade body 51.

[0052] Therefore, in this embodiment, with the central position of the blade body 51 in the blade height direction Dh as the reference, the opening ratio, which is the area of ​​the blade surface outlets 75 per unit area on the hub side Dhh, is made higher than the opening ratio, which is the area of ​​the blade surface outlets 75 per unit area on the tip side Dht, thereby improving the film cooling effect in the hub side Dhh portion and increasing the durability of the blade 50.

[0053] The blade-body cooling passage section 65 of this embodiment has three in-blade passages 66, and therefore, in the first in-blade passage 66a at the foremost Df, the cooling air Ac flows from the hub side Dhh to the tip side Dht. Therefore, the cooling air Ac on the tip side Dht in the first in-blade passage 66a is heated more than the cooling air Ac on the hub side Dhh in this first in-blade passage 66a.

[0054] Therefore, in this embodiment, the opening ratio, which is the area of ​​the front jet ports 73 per unit area on the tip side Dht, is set higher than the opening ratio, which is the area of ​​the front jet ports 73 per unit area on the hub side Dhh, with reference to the central position in the blade height direction Dh of the blade body 51. As a result, in this embodiment, the flow rate of the cooling air Ac ejected from the front jet ports 73 on the tip side Dht is greater than the flow rate of the cooling air Ac ejected from the front jet ports 73 on the hub side Dhh, thereby improving the durability of the rotor blade 50.

[0055] In this embodiment, the cooling air Ac flowing into the multiple film holes 74 is cooling air Ac that has flowed from the third in-blade passage 66c, the rearmost Db, of the three in-blade passages 66, to the downstream portion of the second in-blade passage 66b, and is already heated to a certain extent. Here, the "downstream" refers to the downstream side of the flow of the cooling air Ac. In this embodiment, the cooling air Ac that has been heated to a certain extent and has a reduced convective cooling effect is used as film cooling air. This prevents waste of the cold cooling air Ac, and allows the blade surface 52 to be cooled efficiently. In this embodiment, the cooling air Ac flowing into the multiple front jet holes 72 is cooling air Ac that has flowed from the third in-blade passage 66c, the rearmost Db, of the three in-blade passages 66, to the first in-blade passage 66a, and is already heated to a certain extent. In this embodiment, the cooling air Ac that has been heated considerably and has a reduced convection cooling effect is utilized as cooling air for the leading edge surrounding portion 56, which is a part of the blade surface 52, so that the cold cooling air Ac is not wasted and the blade surface 52 can be cooled efficiently.

[0056] The flow velocity of the combustion gas G flowing along the negative pressure surface 54n, which is a convex curved surface, is higher than the flow velocity of the combustion gas G flowing along the positive pressure surface 54p, which is a concave curved surface. Therefore, the heat transfer coefficient between the combustion gas G flowing along the negative pressure surface 54n and this negative pressure surface 54n is higher than the heat transfer coefficient between the combustion gas G flowing along the positive pressure surface 54p and this positive pressure surface 54p. In other words, the negative pressure surface 54n is more easily heated by the combustion gas G than the positive pressure surface 54p.

[0057] Therefore, in this embodiment, the blade surface outlets 75 are formed only on the suction surface 54n, and the suction surface 54n is film-cooled to improve the durability of the rotor blade 50, while the blade surface outlets 75 are not formed on the pressure surface 54p, which is less likely to be heated by the combustion gas G than the suction surface 54n, thereby reducing the use of cooling air Ac.

[0058] Therefore, in this embodiment, the durability of the rotor blades 50 can be improved while reducing the amount of cooling air Ac used.

[0059] "Second embodiment of rotor blade" A second embodiment of the rotor blade will be described with reference to FIGS.

[0060] Like the blade 50 in the first embodiment, the blade 50a in this embodiment includes a blade body 51, a platform 58, a first cooling air passage 60a, and a second cooling air passage 80. The configuration of the blade 50a in this embodiment, excluding the configuration of the first cooling air passage 60a, is the same as the configuration of the blade 50 in the first embodiment, excluding the configuration of the first cooling air passage 60.

[0061] Like the first cooling air passage 60 in the first embodiment, the first cooling air passage 60a in this embodiment also has a main passage 61, a tip hole 71, a plurality of front injection holes 72, and a plurality of film holes 74a. The main passage 61 opens at the bottom surface 59b of the blade root 59 and has an inlet 63 through which cooling air Ac from the rotor shaft 42 can flow in. Like the main passage 61 of the first cooling air passage 60 in the first embodiment, this main passage 61 has an introduction passage section 62 extending from the inlet 63 in the blade height direction Dh to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage section 65 having three intra-blade passages 66 extending in the blade height direction Dh within the blade body 51. Similar to the blade-body cooling passage 65 of the first cooling air passage 60 in the first embodiment, the blade-body cooling passage 65 has three in-blade passages 66, each of which has a serpentine passage undulating in the blade height direction Dh. Adjacent in-blade passages 66 communicate with each other at one of their hub-side ends Dhh and tip-side ends Dht. Similar to the tip holes 71 of the first cooling air passage 60 in the first embodiment, the tip holes 71 communicate with the tip-side ends Dht of the first in-blade passages 66a and open at the tip surface 55. Similar to the front holes 72 of the first cooling air passage 60 in the first embodiment, each of the front holes 72 has a front outlet 73 that opens at the leading edge surrounding portion 56, which is a portion of the blade surface 52 that includes the leading edge 53f and faces the forward side Df, and communicates with the first in-blade passage 66a.

[0062] Like the multiple film holes 74 in the first embodiment, the multiple film holes 74a in this embodiment have blade surface outlets 75 that open on the suction surface 54n of the blade surface 52, excluding the leading edge surrounding portion 56. In this embodiment as well, with reference to the center position of the suction surface 54n in the blade height direction Dh, the aperture ratio, which is the area of ​​the blade surface outlets 75 per unit area, in the hub-side portion Dhh is higher than the aperture ratio, which is the area of ​​the blade surface outlets 75 per unit area, in the tip-side portion Dht. However, the multiple film holes 74a in this embodiment communicate with the first in-blade passage 66a, which is the most forward Df of the three in-blade passages 66.

[0063] Therefore, the cooling air Ac that flows into the multiple film holes 74a is cooling air Ac that has flowed from the third in-blade passage 66c, the rearmost Db of the three in-blade passages 66, through the second in-blade passage 66b, to the upstream portion of the first in-blade passage 66a, and is already significantly heated. In this embodiment, the cooling air Ac that has been significantly heated and has a reduced convective cooling effect is used as air for film cooling, so that the cold cooling air Ac is not wasted and the blade surface 52 can be cooled more efficiently than in the first embodiment.

[0064] "Third embodiment of rotor blade" A third embodiment of the rotor blade will be described with reference to Figures 9 and 10. Note that Figure 9 is a side view of the rotor blade, similar to Figures 3 and 7, but is not a side view of the rotor blade seen from the suction surface side, but a side view of the rotor blade seen from the pressure surface side.

[0065] Like the blade 50 in the first embodiment, the blade 50b in this embodiment includes a blade body 51, a platform 58, a first cooling air passage 60b, and a second cooling air passage 80. The configuration of the blade 50b in this embodiment, excluding the configuration of the first cooling air passage 60b, is the same as the configuration of the blade 50 in the first embodiment, excluding the configuration of the first cooling air passage 60.

[0066] Like the first cooling air passage 60 in the first embodiment, the first cooling air passage 60b in this embodiment also has a main passage 61, a tip hole 71, a plurality of front injection holes 72, and a plurality of film holes 74b. The main passage 61 opens at the bottom surface 59b of the blade root 59 and has an inlet 63 through which cooling air Ac from the rotor shaft 42 can flow in. Like the main passage 61 of the first cooling air passage 60 in the first embodiment, this main passage 61 has an introduction passage section 62 extending from the inlet 63 in the blade height direction Dh to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage section 65 having three intra-blade passages 66 extending in the blade height direction Dh within the blade body 51. Similar to the blade-body cooling passage 65 of the first cooling air passage 60 in the first embodiment, the blade-body cooling passage 65 has three in-blade passages 66, each of which has a serpentine passage undulating in the blade height direction Dh. Adjacent in-blade passages 66 communicate with each other at one of their hub-side ends Dhh and tip-side ends Dht. Similar to the tip holes 71 of the first cooling air passage 60 in the first embodiment, the tip holes 71 communicate with the tip-side ends Dht of the first in-blade passages 66a and open at the tip surface 55. Similar to the front holes 72 of the first cooling air passage 60 in the first embodiment, each of the front holes 72 has a front outlet 73 that opens at the leading edge surrounding portion 56, which is a portion of the blade surface 52 that includes the leading edge 53f and faces the forward side Df, and communicates with the first in-blade passage 66a.

[0067] The multiple film holes 74b in this embodiment include multiple suction-side film holes 74bn and multiple pressure-side film holes 74bp. The multiple suction-side film holes 74bn have suction surface outlets 75n as blade surface outlets that open on the suction surface 54n of the blade surface 52 excluding the leading edge around portion 56. The multiple pressure-side film holes 74bp have pressure surface outlets 75p as blade surface outlets that open on the pressure surface 54p of the blade surface 52 excluding the leading edge around portion 56. Like the film holes 74 in the first embodiment, the suction-side film holes 74bn communicate with the second in-blade passage 66b. Meanwhile, the pressure-side film holes 74bp communicate with the first in-blade passage 66a.

[0068] In this embodiment, too, the aperture ratio, which is the area of ​​the suction surface outlets 75n per unit area in the hub-side Dhh portion, based on the center position of the suction surface 54n in the blade height direction Dh, is higher than the aperture ratio, which is the area of ​​the suction surface outlets 75n per unit area in the tip-side Dht portion. Furthermore, the aperture ratio, which is the area of ​​the pressure surface outlets 75p per unit area in the hub-side Dhh portion, based on the center position of the pressure surface 54p in the blade height direction Dh, is higher than the aperture ratio, which is the area of ​​the pressure surface outlets 75p per unit area in the tip-side Dht portion. However, the number of pressure-side film holes 74bp is smaller than the number of suction-side film holes 74bn.

[0069] In this embodiment, not only the suction surface 54n but also the pressure surface 54p can be film cooled. As such, in this embodiment, because not only the suction surface 54n but also the pressure surface 54p are film cooled, the amount of cooling air Ac used is greater than in the previous embodiments. Therefore, in this embodiment, the number of pressure-side film holes 74bp for film cooling the pressure surface 54p, which is less likely to be heated by the combustion gas G than the suction surface 54n, is made fewer than the number of suction-side film holes 74bn. Furthermore, in this embodiment, the pressure-side film holes 74bp are connected to the first in-blade passage 66a, so that the cold cooling air Ac is not wasted and the pressure surface 54p is efficiently film-cooled.

[0070] Although this embodiment is a modification of the first embodiment, the second embodiment may also have a plurality of positive pressure side film holes in addition to a plurality of negative pressure side film holes, as in the present embodiment.

[0071] "Other Modifications of the Moving Blade" In each of the above embodiments and modifications, the number of nozzles in the hub-side Dhh portion is made different from the number of nozzles in the tip-side Dht portion to make the aperture ratio of the nozzles in the hub-side Dhh portion different from the number of nozzles in the tip-side Dht portion. However, the aperture ratio of the nozzles in the hub-side Dhh portion may also be made different from the aperture area of ​​each nozzle in the tip-side Dht portion.

[0072] In addition, the above embodiments are all directed to the first stage rotor blade. Other than first dan For example, the rotor blades of the second stage may be targeted.

[0073] The present disclosure is not limited to the above-described embodiments and modifications, and various additions, modifications, substitutions, partial deletions, etc. are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents.

[0074] "Addendum" The rotor blades in the above-described embodiment and modified examples can be understood, for example, as follows.

[0075] (1) The rotor blade in the first aspect is The blade body 51 has a blade-shaped cross section and extends in a blade height direction Dh including a directional component perpendicular to the cross section, and has a tip side Dht and a hub side Dhh in the blade height direction Dh, and includes a platform 58 provided at the end of the hub side Dhh of the blade body 51, a blade root 59 provided on the hub side Dhh of the platform 58, and cooling air passages 60, 60a, 60b formed from the blade root 59, the platform 58 and the blade body 51 and through which cooling air Ac can flow. The blade body 51 has a blade surface 52 facing in a direction having a directional component perpendicular to the blade height direction Dh, and a tip surface 55 facing the tip side Dht in the blade height direction Dh. The blade surface 52 has a leading edge 53 f and a trailing edge 53 b extending in the blade height direction Dh, and a pressure surface 54 p and a suction surface 54 n expanding from the leading edge 53 f to the trailing edge 53 b. The cooling air passages 60, 60 a, 60 b each have a main passage 61 having an inlet 63 that opens on the surface of the blade root 59 and allows cooling air Ac to flow in, and a front outlet 73 that opens in a leading edge surrounding portion 56 that includes the leading edge 53 f and faces the front side Df that is on the leading edge 53 f side relative to the trailing edge 53 b, extends in a direction in which a component in a direction parallel to a normal to the blade surface 52 at the position of the front jet port 73 is greater than a component in a direction parallel to a tangent to the blade surface 52 at the position of the front jet port 73, a plurality of front ejection holes (72) that can eject the cooling air Ac that has passed through the main passage (61) from the front ejection port (73); and blade surface ejection ports (75, 75n, 75p) that are open on the blade surface (52) except for the leading edge surrounding portion (56) and on at least one of the pressure surface (54p) and the suction surface (54n), The blade surface 52 extends in a direction in which the component parallel to the tangent to the blade surface 52 at the position of the blade surface outlet 75 is greater than the component parallel to the normal to the blade surface 52 at the position of the blade surface outlet 75, and in a direction toward the trailing edge 53b side Db,The cooling air Ac passing through the main passage 61 has a plurality of film holes 74, 74a, 74b that can eject the cooling air Ac from the blade surface outlets 75, 75n, 75p to the outside along at least one of the blade surfaces 52. The main passage 61 has an introduction passage section 62 extending from the inlet 63 to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage section 65 having three or more odd number of in-blade passages 66 extending in the blade height direction Dh within the blade body 51. The odd number of in-blade passages 66 are aligned from the introduction passage section 62 to the forward side Df along the camber line CL of the blade body 51. Adjacent intra-blade passages 66 among the odd number of intra-blade passages 66 communicate with one of the hub-side (Dhh) and tip-side (Dht) ends so that the blade-body cooling passage portion 65 forms a single serpentine passage undulating in the blade height direction (Dh). The plurality of front injection holes 72 communicate with the first intra-blade passage 66a, which is the most forward (Df) of the odd number of intra-blade passages 66. The plurality of film holes 74, 74a, 74b communicate with at least one of the first intra-blade passage 66a and the second intra-blade passage 66b adjacent to the first intra-blade passage 66a, among the odd number of intra-blade passages 66. With reference to the central position of the blade height direction Dh of the blade body 51, the opening ratio, which is the area of ​​the blade surface outlets 75, 75n, 75p per unit area on the hub side Dhh, is higher than the opening ratio, which is the area of ​​the blade surface outlets 75, 75n, 75p per unit area on the tip side Dht.

[0076] In this embodiment, the cooling air Ac that flows into the main passage 61 from the inlet 63 of the main passage 61 in the cooling air passages 60, 60a, 60b passes through the introduction passage section 62 of the main passage 61 and flows into the blade-body cooling passage section 65 of the main passage 61. As the cooling air Ac flows through three or more odd number of in-blade passages 66 in the blade-body cooling passage section 65, it convectively cools the periphery of each in-blade passage 66. A portion of the cooling air Ac flowing through the three or more odd number of in-blade passages 66 is ejected to the outside from the multiple film holes 74, 74a, 74b along the pressure surface 54p or the suction surface 54n. As the cooling air Ac flows through the multiple film holes 74, 74a, 74b, it convectively cools the periphery of the film holes 74, 74a, 74b. Furthermore, the cooling air Ac ejected from the multiple film holes 74, 74a, 74b film-cools the pressure surface 54p or the suction surface 54n. Of the three or more odd number of in-blade passages 66, a portion of the cooling air Ac that flows into the first in-blade passage 66a, which is located at the most forward side Df and downstream of the flow of the cooling air Ac, is ejected to the outside from the multiple front injection holes 72. As this portion of the cooling air Ac flows through the multiple front injection holes 72, it convectively cools the areas around the front injection holes 72. Furthermore, the cooling air Ac ejected from the multiple front injection holes 72 prevents the high-temperature combustion gas G from directly impinging on the leading edge surrounding region 56, which is part of the blade surface 52.

[0077] The blade width, which is the distance between the pressure surface 54p and the suction surface 54n, gradually increases from the tip side Dht to the hub side Dhh of the blade body 51. The distance between the inner surface of the in-blade passage 66 and the blade surface 52 is within a predetermined range from the viewpoint of cooling the blade surface 52. Accordingly, the width of the multiple in-blade passages 66 extending in the blade height direction Dh also gradually increases from the tip side Dht to the hub side Dhh of the blade body 51. If the width of the in-blade passage 66 gradually increases from the tip side Dht to the hub side Dhh of the blade body 51, the flow velocity of the cooling air Ac flowing through the in-blade passage 66 becomes lower on the hub side Dhh than on the tip side Dht. Therefore, the heat transfer coefficient between the cooling air Ac flowing through the hub side Dhh of the in-blade passage 66 and the blade body 51 is lower than the heat transfer coefficient between the cooling air Ac flowing through the tip side Dht of the in-blade passage 66 and the blade body 51. Therefore, the convection cooling effect of the cooling air Ac flowing through the in-blade passage 66 is reduced in the portion Dhh on the hub side of the blade body 51.

[0078] Therefore, in this embodiment, the opening ratio, which is the area of ​​the blade surface outlets 75, 75n, 75p per unit area on the hub side Dhh, is made higher than the opening ratio, which is the area of ​​the blade surface outlets 75, 75n, 75p per unit area on the tip side Dht, based on the central position of the blade height direction Dh on the blade body 51, thereby improving the film cooling effect in the hub side Dhh portion and increasing the durability of the blade 50.

[0079] Furthermore, in this embodiment, the cooling air Ac flowing into the multiple film holes 74, 74a, 74b is cooling air Ac that has flowed from the rearmost Db in-blade passage 66 among the three or more odd number of in-blade passages 66 to at least the downstream portion of the second in-blade passage 66b, and is already heated to a certain extent. Here, the downstream side refers to the downstream side of the flow of the cooling air Ac. In this embodiment, the cooling air Ac that has been heated to a certain extent and has a reduced convective cooling effect is used as air for film cooling. This prevents waste of the cold cooling air Ac, and allows the blade surface 52 to be cooled efficiently. Furthermore, in this embodiment, the cooling air Ac flowing into the multiple front injection holes 72 is cooling air Ac that has flowed from the rearmost Db in-blade passage 66 among the three or more odd number of in-blade passages 66 to the first in-blade passage 66a, and is already heated to a certain extent. Here, the upstream side refers to the downstream side of the flow of the cooling air Ac. In this embodiment, the cooling air Ac, which has been heated considerably and has a reduced convection cooling effect, is utilized as cooling air for the leading edge surrounding portion 56, which is a part of the blade surface 52, so that the cold cooling air Ac is not wasted and the blade surface 52 can be cooled efficiently.

[0080] Therefore, in this embodiment, the durability of the rotor blade can be improved while reducing the amount of cooling air Ac used.

[0081] (2) The rotor blade in the second embodiment is In the rotor blade of the first embodiment, the number of the blade surface outlets 75, 75n, 75p is greater on the hub side Dhh than on the tip side Dht, with reference to the center position of the blade body 51 in the blade height direction Dh.

[0082] (3) The rotor blade in the third embodiment is In the rotor blade of the first embodiment, the blade surface outlets 75, 75n, 75p are present only on the hub side Dhh with reference to the center position of the blade body 51 in the blade height direction Dh, and are not present on the tip side Dht.

[0083] (4) The rotor blade in the fourth aspect is In the rotor blade according to any one of the first to third embodiments, the film holes 74a communicate with only the first in-blade passage 66a among the odd number of in-blade passages 66.

[0084] In this embodiment, the cooling air Ac flowing into the multiple film holes 74a is cooling air Ac that has flowed from the rearmost in-blade passage 66 Db among the three or more odd-numbered in-blade passages 66, through the second in-blade passage 66b, and to the upstream portion of the first blade passage section, and is already significantly heated. In this embodiment, the cooling air Ac that has been significantly heated and has a reduced convective cooling effect is used as air for film cooling, so that the cold cooling air Ac is not wasted and the blade surface 52 can be cooled efficiently.

[0085] (5) In the fifth aspect, the rotor blade is In the rotor blade according to any one of the first to fourth embodiments, the blade surface outlet 75 is formed only on the suction surface 54n.

[0086] The flow velocity of the combustion gas G flowing along the negative pressure surface 54n, which is a convex curved surface, is higher than the flow velocity of the combustion gas G flowing along the positive pressure surface 54p, which is a concave curved surface. Therefore, the heat transfer coefficient between the combustion gas G flowing along the negative pressure surface 54n and this negative pressure surface 54n is higher than the heat transfer coefficient between the combustion gas G flowing along the positive pressure surface 54p and this positive pressure surface 54p. In other words, the negative pressure surface 54n is more easily heated by the combustion gas G than the positive pressure surface 54p.

[0087] Therefore, in this embodiment, the blade surface outlets 75 are formed only on the suction surface 54n, and the suction surface 54n is film-cooled to improve the durability of the rotor blade 50, while the blade surface outlets are not formed on the pressure surface 54p, which is less likely to be heated by the combustion gas G than the suction surface 54n, thereby reducing the use of cooling air Ac.

[0088] (6) The rotor blade in the sixth aspect is In a blade in any one of the first to fifth embodiments, the opening ratio, which is the area of ​​the front jet port 73 per unit area on the tip side Dht, is higher than the opening ratio, which is the area of ​​the front jet port 73 per unit area on the hub side Dhh, based on the central position of the blade body 51 in the blade height direction Dh.

[0089] Since the blade-body cooling passage section 65 of this embodiment has an odd number (three or more) of in-blade passages 66, the cooling air Ac flows from the hub side Dhh to the tip side Dht in the first in-blade passage 66a at the foremost Df. Therefore, the cooling air Ac on the tip side Dht in the first in-blade passage 66a is heated more than the cooling air Ac on the hub side Dhh in this first in-blade passage 66a.

[0090] Therefore, in this embodiment, the opening ratio, which is the area of ​​the front jet ports 73 per unit area on the tip side Dht, is set higher than the opening ratio, which is the area of ​​the front jet ports 73 per unit area on the hub side Dhh, with reference to the central position in the blade height direction Dh of the blade body 51. As a result, in this embodiment, the flow rate of the cooling air Ac ejected from the front jet ports 73 on the tip side Dht is greater than the flow rate of the cooling air Ac ejected from the front jet ports 73 on the hub side Dhh, thereby improving the durability of the rotor blade 50.

[0091] (7) The rotor blade in the seventh aspect is In a rotor blade according to any one of the first to sixth embodiments, the cooling air passages 60, 60a, 60b are connected to the end of the tip side Dht of the first intra-blade passage 66a and have a tip hole 71 that allows the cooling air Ac that has passed through the first intra-blade passage 66a to be ejected from the tip surface 55.

[0092] The blade-body cooling passage section 65 of this embodiment has an odd number (three or more) of in-blade passages 66, and therefore, in the first in-blade passage 66a at the foremost Df, cooling air Ac flows from the hub side Dhh to the tip side Dht. If the tip holes 71 were not provided, the flow of cooling air Ac would be stagnant in the tip-side Dht portion of the first in-blade passage 66a, reducing the convective cooling effect in this tip-side Dht portion. Therefore, in this embodiment, the provision of the tip holes 71 ensures the flow of cooling air Ac in the tip-side Dht portion of the first in-blade passage 66a, thereby preventing a reduction in the convective cooling effect in this tip-side Dht portion.

[0093] (8) In the eighth aspect, the rotor blade is In the blade according to any one of the first to seventh embodiments, in addition to the first cooling air passages 60, 60a, 60b which are the cooling air passages 60, 60a, 60b, a second cooling air passage 80 is provided which is formed across the blade root 59, the platform 58 and the blade body 51 and through which cooling air Ac can flow. The second cooling air passage 80 is arranged on a rear side Db which is closer to the trailing edge 53b than the leading edge 53f with respect to the first cooling air passages 60, 60a, 60b, and has a main passage 81 which has an inlet 83 that opens on the surface of the blade root 59 and through which the cooling air Ac can flow, and a plurality of rear ejection holes 88 which have rear ejection ports 89 which can eject the cooling air Ac which has passed through the main passage 81 to the outside from the trailing edge 53b. The main passage 81 in the second cooling air passage 80 has an introduction passage portion 82 extending from the inlet 83 in the second cooling air passage 80 to the boundary between the platform 58 and the blade body 51, and a blade-body cooling passage portion 85 having a plurality of in-blade passages 86 extending in the blade height direction Dh within the blade body 51. The plurality of in-blade passages 86 in the second cooling air passage 80 are aligned along the camber line CL of the blade body 51 from the introduction passage portion 82 in the second cooling air passage 80 to the rear side Db. Adjacent in-blade passages 86 of the plurality of in-blade passages 86 in the second cooling air passage 80 communicate with each other at one of their ends on the hub side Dhh and the tip side Dht so that the blade-body cooling passage portion 85 in the second cooling air passage 80 forms a single serpentine passage that is undulating in the blade height direction Dh. The plurality of rear injection holes 88 communicate with the rearmost intra-blade passage 86c on the rearmost side Db among the plurality of intra-blade passages 86 in the second cooling air passage 80.

[0094] In this aspect, while the cooling air Ac flows through the multiple in-blade passages 86 of the second cooling air passage 80, the cooling air Ac convectively cools the area around each in-blade passage 86. Of the multiple in-blade passages 86, a portion of the cooling air Ac flowing through the rearmost in-blade passage 86c on the rearmost side Db is ejected to the outside from the multiple rear ejection holes 88. While flowing through the multiple rear ejection holes 88, the portion of the cooling air Ac convectively cools the area around the rear ejection holes 88. Furthermore, the cooling air Ac ejected from the multiple rear ejection holes 88 suppresses the generation of a wake of combustion gas G on the rear side Db of the trailing edge 53b.

[0095] The gas turbines in the above-described embodiments and modifications can be understood, for example, as follows. (9) A gas turbine according to a ninth aspect includes: The turbine turbine is equipped with a rotor shaft 42 having a plurality of rotor blades according to any one of the first to eighth embodiments, rotatable about an axis Ar, and having a plurality of the rotor blades attached to the rotor shaft 42 in a line in a circumferential direction Dc relative to the axis Ar, and a turbine casing 45 covering the outer periphery of the rotor blades and the rotor shaft 42. The rotor blades have a blade height direction Dh that corresponds to a radial direction Dr relative to the axis Ar, and the hub side Dhh corresponds to the radial direction Dri of the radially inner side and the radially outer side Dro of the radial direction Dr relative to the axis Ar. Medial Dri and the front side Df is attached to the rotor shaft 42 so as to be on the axial upstream side Dau of the axial upstream side Dau and the axial downstream side Dad in the axial direction Da in which the axis Ar extends. [Explanation of symbols]

[0096] 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 50,50a,50b: 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 56: Leading edge area 58: Platform 59: Wing root 59b: Bottom 60, 60a, 60b: First cooling air passage (or simply cooling air passage) 61: Main passage 62: Entry passage 63: Entrance 65: Wing body cooling passage section 66: Inner wing passage 66a: First wing passage 66b: Second wing passage 66c: Passage in the third wing 71: Chip hole 72: Front vent 73: Front spout 74, 74a, 74b: Film holes 74bn: Negative pressure side film hole 74bp: Pressure side film hole 75: Wing surface outlet 75n: Suction surface outlet (wing surface outlet) 75p: Pressure surface outlet (wing surface outlet) 80: Second cooling air passage 81: Main passage 82: Introduction passage 83: Entrance 85: Wing body cooling passage section 86: Inner wing passage 86a: Passage in the fourth wing 86b: Passage in the fifth wing 86c: Passage in the sixth wing (passage in the rearmost wing) 88: Post-spout hole 89: Rear spout A: Air Ac: Cooling air F:Fuel G: Combustion gas Ar: Axis line CL: Camber line Da: Axial direction Dau: Axis upstream side Dad: Downstream of the axis Dc: Circumferential direction Dr: Radial direction Dri: Radial inner direction Dro: Radial outer side Dh: Wing height direction Dhh: Hub side Dht: Chip side Df: Front Db: Rear side

Claims

1. A wing body having a cross section that forms an airfoil shape and extends in a wing height direction including a directional component perpendicular to the cross section; a platform provided at an end of the blade body on the hub side, between 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 from the leading edge to the trailing edge, The cooling air passage is a main passage having an inlet opening at the surface of the blade root and allowing cooling air to flow in; a plurality of front injection holes having a front injection port that opens at a leading edge periphery that is a portion of the blade surface that includes the leading edge and faces forward relative to the trailing edge, the front injection holes extending in a direction in which a component of a direction parallel to a normal to the blade surface at the position of the front injection port is greater than a component of a direction parallel to a tangent to the blade surface at the position of the front injection port, and capable of ejecting, from the front injection port, the cooling air that has passed through the main passage; a plurality of film holes having blade surface outlets that are open on at least one of the pressure surface and the suction surface, excluding the leading edge portion, and that extend in a direction toward the trailing edge in which a component parallel to a tangent to the blade surface at the position of the blade surface outlet is greater than a component parallel to a normal to the blade surface at the position of the blade surface outlet, and that are capable of ejecting cooling air that has passed through the main passage from the blade surface outlet to the outside along the at least one blade surface; and the main passage has an introduction passage section extending from the inlet to a boundary between the platform and the blade body, and a blade body cooling passage section having an odd number of intra-blade passages (three or more) extending in the blade height direction within the blade body, an odd number of the in-blade passages are arranged along the camber line of the blade body from the introduction passage portion to the forward side, the blade-body cooling passage portion forms a single serpentine passage in the blade height direction, and adjacent ones of the odd number of the blade-body cooling passages communicate with each other at one of the hub-side end and the tip-side end, the plurality of front jet holes communicate with the first in-blade passage, which is the most forward of the odd number of in-blade passages; the plurality of film holes communicate with at least one of the first intra-blade passage and a second intra-blade passage adjacent to the first intra-blade passage among the odd number of intra-blade passages, an opening ratio, which is the area of ​​the blade surface outlet per unit area on the hub side, based on a central position in the blade height direction of the blade body, is higher than an opening ratio, which is the area of ​​the blade surface outlet per unit area on the tip side; Moving blade.

2. The rotor blade according to claim 1 , the number of the blade surface outlets is greater on the hub side than on the tip side with respect to the center position of the blade body in the blade height direction; Moving blade.

3. The rotor blade according to claim 1 , the blade surface outlet is present only on the hub side with respect to a central position of the blade body in the blade height direction, and is not present on the tip side; Moving blade.

4. The rotor blade according to any one of claims 1 to 3, the plurality of film holes communicate with only the first in-blade passage among the odd number of in-blade passages; Moving blade.

5. The rotor blade according to any one of claims 1 to 3, the blade surface outlet is formed only on the suction surface, Moving blade.

6. The rotor blade according to any one of claims 1 to 3, an opening ratio, which is the area of ​​the front jet port per unit area on the tip side, based on a central position in the blade height direction of the blade body, is higher than an opening ratio, which is the area of ​​the front jet port per unit area on the hub side; Moving blade.

7. The rotor blade according to any one of claims 1 to 3, the cooling air passage is in communication with the tip side end of the first in-blade passage and has a tip exhaust hole through which the cooling air that has passed through the first in-blade passage can be ejected from the tip surface. Moving blade.

8. The rotor blade according to any one of claims 1 to 3, a second cooling air passage formed across the blade root, the platform and the blade body, through which cooling air can flow, in addition to the first cooling air passage, which is the cooling air passage; The second cooling air passage is the first cooling air passage is located on a rear side of the first cooling air passage that is closer to the trailing edge than the leading edge; a main passage having an inlet opening at the surface of the blade root and allowing cooling air to flow in; a plurality of rear ejection holes each having a rear ejection port capable of ejecting the cooling air that has passed through the main passage to the outside from the trailing edge; and the main passage in the second cooling air passage has an introduction passage section extending from the inlet of the second cooling air passage to a boundary between the platform and the blade body, and a blade body cooling passage section having a plurality of intra-blade passages extending in the blade height direction within the blade body, the plurality of in-blade passages in the second cooling air passage are aligned along a camber line of the blade body from the introduction passage portion in the second cooling air passage to the rear side, adjacent in-blade passages among the plurality of in-blade passages in the second cooling air passage communicate with each other at one of the hub-side end and the tip-side end so that the blade-body cooling passage portion in the second cooling air passage forms a single serpentine passage in which the passage is undulating in the blade height direction, the plurality of rear injection holes communicate with the rearmost rearmost intra-blade passage among the plurality of intra-blade passages in the second cooling air passage; Moving blade.

9. A rotor blade according to any one of claims 1 to 3, a rotor shaft rotatable about an axis line, and having a plurality of the rotor blades attached to the rotor shaft so as to be arranged in a circumferential direction with respect to the axis line; a turbine casing that covers the plurality of rotor blades and an outer peripheral side of the rotor shaft; Equipped with the rotor blades are attached to the rotor shaft such that the blade height direction is a radial direction relative to the axis, the hub side is the radially inner side of a radially inner side and a radially outer side in the radial direction relative to the axis, and the front side is the axially upstream side of an axially upstream side and an axially downstream side in the axial direction in which the axis extends. Gas turbine.

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