Turbine blade

Abstract

This turbine blade comprises a blade wall, and an insert inserted into a space formed inside the blade wall. An internal cavity communicating with the outside of the turbine blade is formed inside the insert body part of the insert. A plurality of ridges protruding toward the inner surface of the blade wall and having an opposing surface facing the inner surface of the blade wall are formed on the outer surface of the insert body part. Each of the plurality of ridges has a flow passage communicating with the internal cavity, and a plurality of cooling holes communicating with the flow passage, opening on the opposing surface, and arranged along the longitudinal direction of the plurality of ridges. A recovery space is defined between adjacent two ridges out of the plurality of ridges. Between the outer surface of the insert body part and the inner surface of the blade wall, and between the hub-side edge of the blade wall and the hub-side end of the ridges in the longitudinal direction or between the tip-side edge of the blade wall and the tip-side end of the ridges, a recovery flow path communicating with the recovery space is defined. A discharge hole for communicating the recovery flow path with the outside of the turbine blade is formed in the blade wall.

Description

Turbine blades

[0001] This application claims priority to Japanese Patent Application No. 2023-143156, filed with the Japan Patent Office on September 4, 2023, the contents of which are incorporated herein by reference.

[0002] Patent Document 1 describes a turbine blade that can be cooled by impingement cooling. In this turbine blade, an insert is provided in a space formed inside a blade wall, and the insert is formed with a plurality of ridges that protrude toward the inner surface of the blade wall, and a cooling hole for ejecting a cooling medium is formed at the tip of each ridge. The cooling medium ejected from the cooling holes collides with the inner surface of the blade wall, thereby cooling the blade wall. The cooling medium that collides with the inner surface of the blade wall flows through a recovery space defined between adjacent ridges and is then discharged to the outside of the turbine blade.

[0003] If a cross flow occurs, in which the coolant flows along the inner surface between the insert and the inner surface of the blade wall after colliding with the inner surface of the blade wall, the cross flow may interfere with the coolant ejected from the cooling holes, thereby reducing the cooling efficiency of the blade wall. In contrast, the turbine blade described in Patent Document 1 reduces the cross flow by having the coolant flow through the recovery space after colliding with the inner surface of the blade wall.

[0004] JP 2015-63997 A

[0005] However, in a configuration in which multiple protrusions extend to the shroud, the cooling medium that has circulated through the recovery space must flow out from inside the blade wall through narrow gaps between the multiple protrusions and the inner surface of the blade wall, which makes it difficult to allow the cooling medium to flow out from inside the blade wall.

[0006] In view of the above circumstances, at least one embodiment of the present disclosure has an object to provide a turbine blade that facilitates the flow of a cooling medium that has cooled the blade wall from inside the blade wall.

[0007] In order to achieve the above object, the turbine blade according to the present disclosure is a turbine blade including a blade wall and an insert inserted into a space formed inside the blade wall, wherein an internal cavity communicating with the outside of the turbine blade is formed inside an insert body of the insert, and a plurality of ridges are formed on the outer surface of the insert body, the ridges protruding toward the inner surface of the blade wall and having opposing surfaces facing the inner surface of the blade wall, and each of the plurality of ridges has a flow path communicating with the internal cavity and a flow path communicating with the flow path and having opposing surfaces facing the opposing surfaces. a recovery space is defined between two adjacent ridges; a recovery flow path communicating with the recovery space is defined between the outer surface of the insert body and the inner surface of the blade wall, and between the hub-side edge of the blade wall and the hub-side end of the ridge or between the tip-side edge of the blade wall and the tip-side end of the ridge; and a discharge hole communicating the recovery flow path with the outside of the turbine blade is formed in the blade wall.

[0008] According to the turbine blade of the present disclosure, the cooling medium that has circulated through each recovery space joins together within the recovery flow path and flows out of the recovery flow path through the discharge hole, making it easier for the cooling medium that has cooled the blade wall to flow out from inside the blade wall.

[0009] 1 is a schematic configuration diagram of a gas turbine according to all embodiments of the present disclosure.

[0023] FIG. 1 is a diagram of a turbine blade according to a first embodiment of the present disclosure, viewed in a direction from the pressure surface to the suction surface.

[0024] FIG. 2 is a cross-sectional view taken along line III-III of FIG. 2.

[0025] FIG. 2 is a cross-sectional view taken along line IV-IV of FIG. 2.

[0026] FIG. 3 is an enlarged cross-sectional view of a portion of an insert for a turbine blade according to a first embodiment of the present disclosure.

[0027] FIG. 4 is a perspective view for explaining the configuration of a plurality of ridges of the insert for a turbine blade according to a first embodiment of the present disclosure.

[0028] FIG. 5 is a cross-sectional view of a portion of the insert for a turbine blade and a blade wall according to a first embodiment of the present disclosure.

[0029] FIG. 6 is a front view showing the configuration of a portion of the ridges of the insert for a turbine blade according to a second embodiment of the present disclosure.

[0029] FIG. 7 is a front view showing the configuration of a portion of the ridges of the insert for a turbine blade according to a third embodiment of the present disclosure.

[0029] FIG. 8 is a cross-sectional view of the ridges of the insert for a turbine blade according to a fourth embodiment of the present disclosure.

[0029] FIG. 9 is a cross-sectional view of another form of the ridges of the insert for a turbine blade according to the fourth embodiment of the present disclosure.

[0029] FIG. 10 is a front view showing the configuration of a portion of the ridges of the insert for a turbine blade according to a fifth embodiment of the present disclosure.

[0029] FIG. 11 is a front view showing the configuration of a portion of the ridges of a modified example of the insert for a turbine blade according to the fifth embodiment of the present disclosure. Fig. 1 is a front view showing the configuration of a portion of another modified example of the ridges of the insert of the turbine blade according to embodiment 5 of the present disclosure. Fig. 2 is a cross-sectional view of a portion of the blade wall and insert of the turbine blade according to embodiment 6 of the present disclosure. Fig. 3 is a cross-sectional view of a portion of an insert of another form of the turbine blade according to embodiment 6 of the present disclosure. Fig. 4 is a cross-sectional view of a portion of an insert of yet another form of the turbine blade according to embodiment 6 of the present disclosure. Fig. 5 is a cross-sectional view of a portion of a portion of a modified turbine blade according to embodiment 6 of the present disclosure, corresponding to the cross section taken along line III-III in Fig. 2

[0010]

[0016] Hereinafter, a turbine blade according to an embodiment of the present disclosure will be described with reference to the drawings. The embodiment described below shows one aspect of the present disclosure, but does not limit the present disclosure and can be modified as desired within the scope of the technical concept of the present disclosure.

[0011] 1, a gas turbine 1 includes a compressor 2 for generating compressed air, a combustor 4 for generating combustion gas using the compressed air and fuel, and a turbine 6 configured to be rotationally driven by the combustion gas. In the case of a gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0012] The compressor 2 includes a plurality of stator vanes 16 fixed to the compressor casing 10 side and a plurality of moving blades 18 attached to the rotor 8. Air taken in from an air intake 12 is sent to the compressor 2, and this air is compressed as it passes through the plurality of stator vanes 16 and the plurality of moving blades 18, becoming high-temperature, high-pressure compressed air.

[0013] The combustor 4 is supplied with fuel and compressed air generated by the compressor 2, and the fuel and compressed air are mixed in the combustor 4 and then combusted to generate combustion gas, which is the working fluid of the turbine 6. A plurality of combustors 4 may be arranged in the casing 20 along the circumferential direction around the rotor.

[0014] The turbine 6 has a combustion gas flow path 28 formed in a turbine casing 22 and includes a plurality of stator vanes 24 and rotor blades 26 provided in the combustion gas flow path 28. The stator vanes 24 are fixed to the turbine casing 22 side, and a plurality of stator vanes 24 arranged along the circumferential direction of the rotor 8 constitute a stator vane row. The rotor blades 26 are attached to the rotor 8, and a plurality of rotor blades 26 arranged along the circumferential direction of the rotor 8 constitute a rotor blade row. The stator vane rows and rotor blade rows are arranged alternately in the axial direction of the rotor 8.

[0015] (First embodiment) <Configuration of turbine blade according to first embodiment of the present disclosure> The turbine blade according to the first embodiment of the present disclosure is intended for both the stationary blade 24 and the moving blade 26 of the turbine 6. In the following, the turbine blade according to the first embodiment of the present disclosure will be described as the stationary blade 24, but it may also be the moving blade 26.

[0016] As shown in FIG. 2 , the stator vane 24 includes a blade wall 34, which extends from a hub-side edge 34 c toward a tip-side edge 34 b, i.e., in the blade height direction of the stator vane 24. An outer shroud 38 and an inner shroud 40 are provided at the tip-side edge 34 b and the hub-side edge 34 c, respectively. Here, the term “hub side” refers to the side toward the center of the rotation axis in the radial direction of the rotational orbit of the rotor blade 26 (see FIG. 1 ), and the term “tip side” refers to the side toward the outer periphery of the rotational orbit of the rotor blade 26 in the radial direction of the rotational orbit. Therefore, the hub-side edge 34 c and the tip-side edge 34 b correspond to the hub-side edge and the tip-side edge, respectively, as defined above, of the two end edges of the stator vane 24 in the blade height direction. The blade wall 34 has a leading edge 42 and a trailing edge 44 extending along the blade height direction, and a pressure surface 46 and a suction surface 48 extending between the leading edge 42 and the trailing edge 44.

[0017] As will be described later, a space 50 (see FIG. 3) is formed inside the blade wall 34, and a passage 37 is formed in the outer shroud 38 to communicate between the outside of the stator vane 24 and an internal cavity 56 (see FIG. 3) of an insert 51 (see FIG. 3), which will be described later and is provided in the space 50. The passage 37 is not limited to being formed in the outer shroud 38, and may be formed in the inner shroud 40. Although FIG. 2 schematically illustrates one passage 37, a plurality of passages 37 may be provided. The role of the passage 37 will be described later.

[0018] As shown in Fig. 3, a space 50 is formed inside the wing wall 34. The space 50 may be divided into a plurality of spaces, for example, two spaces 50a and 50b, by a middle wall 57. The space 50 may be divided into three or more spaces by two or more middle walls 57, or the space 50 may be a single space without providing a middle wall 57. An insert 51 is inserted into the space 50. As exemplarily shown in Fig. 3, when the space 50 is divided into two spaces 50a and 50b, the insert 51 may include inserts 51a and 51b inserted into each space.

[0019] As shown in FIG. 4 , the outer shroud 38 has a shroud peripheral flow passage 60 formed along its periphery. A supply port 61 is formed at an arbitrary position in the shroud peripheral flow passage 60, and one end of a supply path 62 is connected to the supply port 61. As will be described later, each of the inserts 51 a, 51 b has a plurality of ridges 52 formed to extend along the blade height direction of the stator vane 24, i.e., along a direction perpendicular to the plane of FIG. 4 . Within the space 50 inside the blade wall 34, recovery spaces 53 are defined between adjacent ridges 52, 52, and recovery flow passages 63 communicating with each recovery space 53 are defined. The blade wall 34 has discharge holes 64 formed therein that connect the recovery flow passages 63 to the outside of the blade wall 34, and the other end of the supply path 62 is connected to the discharge holes 64. That is, the recovery flow passages 63 and the shroud peripheral flow passage 60 are connected via the discharge holes 64, the supply path 62, and the supply port 61. The shroud peripheral flow passage 60 has a discharge port 65 formed in any position different from the supply port 61, the discharge port 65 communicating with the outside of the blade wall 34. The shroud peripheral flow passage 60 may be formed not in the outer shroud 38 but in the shroud not provided with the path 37, i.e., in the above-described configuration, in the inner shroud 40 (see FIG. 2 ).

[0020] <Configuration of Insert> As shown in FIG. 3 , the insert 51 (51a, 51b) has a cylindrical insert body 59 (59a, 59b) having a longitudinal axis along the blade height direction of the stator vane 24 (a direction perpendicular to the plane of FIG. 3 ), and an internal cavity 56 (56a, 56b) is formed inside the insert body 59 (59a, 59b). The internal cavity 56 (56a, 56b) communicates with the path 37 (see FIG. 2 ). A plurality of ridges 52 that protrude toward the inner surface 34a of the blade wall 34 are formed on outer surfaces 59a1, 59b1 of the insert body 59a, 59b, respectively. In each insert, the plurality of ridges 52 extend along the blade height direction of the stator vane 24 and are arranged at intervals in the circumferential direction around the longitudinal axis. In each insert, a recovery space 53 is defined between adjacent ridges 52, 52 in the circumferential direction centered on the longitudinal axis.

[0021] Next, the configuration of the ridges 52 will be described. Fig. 5 shows a cross-sectional view of some of the multiple ridges 52 provided on the insert 51a. The configuration of the ridges 52 described below with reference to Fig. 5 also applies to all or some of the multiple ridges 52 provided on the other insert 51b.

[0022] A flow passage 54, which is a cavity that communicates with the internal cavity 56a, is formed inside the rib 52. The rib 52 also has a plurality of cooling holes 55 that communicate with the flow passage 54 and open to face the inner surface 34a of the blade wall 34 (FIG. 5 shows one of the plurality of cooling holes 55 in each rib 52).

[0023] The ridges 52 may be arranged at equal intervals to uniformly cool the entire stator blade 24, or the interval between adjacent ridges 52, 52 at a location where cooling is particularly desired may be smaller than the interval between adjacent ridges 52, 52 at other locations. For example, the interval between the ridges 52, 52 arranged on the ventral side of the stator blade 24 may be smaller than the interval between the ridges 52, 52 arranged on the suction side of the stator blade 24. Furthermore, the ridges 52 arranged on both the ventral side and the suction side of the stator blade 24 may be arranged so that the interval between adjacent ridges 52, 52 gradually increases from the leading edge to the trailing edge of the stator blade 24.

[0024] FIG. 6 shows two adjacent ridges 52a, 52b. The configuration described below also applies to adjacent ridges other than the ridges 52a, 52b. Each of the ridges 52a, 52b has a rail-like shape that protrudes toward the inner surface 34a of the blade wall 34 (see FIG. 3) and extends along the blade height direction of the stator vane 24. The ridges 52a, 52b have a tip-side end 52c and a hub-side end 52d, and an opposing surface 71 (71a, 71b) that faces the inner surface 34a. In the first embodiment, the opposing surface 71 is divided into a first region 72 (72a, 72b) and a second region 73 (73a, 73b). A boundary region 74 (74a, 74b) that connects the first region 72 and the second region 73 is provided between the first region 72 and the second region 73.

[0025] The opposing surface 71 has openings 58 of the multiple cooling holes 55 formed in a row along the longitudinal direction of the ridges 52 (as described above, the direction in which the ridges 52 extend along the blade height direction of the stator vane 24). The number of cooling holes 55 (synonymous with the openings 58a formed in each opposing surface 71) formed in each ridge 52 is arbitrary. The spacing between adjacent cooling holes 55 may be equal or may vary. In the latter configuration, for example, the spacing between adjacent cooling holes 55 may gradually increase from the hub side toward the tip side, or conversely, the spacing between adjacent cooling holes 55 may gradually increase from the tip side toward the hub side.

[0026] 6 illustrates a configuration in which two openings 58 are formed in the first region 72 and five openings 58 are formed in the second region 73, but this configuration is merely an example. The opening 58 of at least one cooling hole 55 is formed in the first region 72. The "opening 58 of at least one cooling hole 55" formed in the first region 72 is the opening 58a of the first cooling hole 55a formed in the position closest to the recovery passage 63 in the longitudinal direction of the ridge 52, i.e., the position closest to the discharge hole 64 (see FIG. 4).

[0027] The first region 72 only needs to have at least the openings 58a of the first cooling holes 55a formed therein, and the number of openings 58 formed therein is arbitrary. For example, the first region 72 may have two openings, opening 58a and one opening 58 located adjacent thereto (corresponding to the configuration in FIG. 6 ), or three openings, opening 58a and two openings 58 located adjacent thereto. The openings other than those formed in the first region 72 are formed in the second region 73. In other words, no openings 58 are formed in the boundary region 74.

[0028] The number of openings 58 formed in each of the first region 72 and the second region 73 depends on the spacing between adjacent openings 58, 58 and the respective lengths of the first region 72 and the second region 73 in the longitudinal direction of the rib protrusion 52, but the number of openings formed in the first region 72 is fewer than the number of openings formed in the second region 73, and the length of the first region 72 in the longitudinal direction of the rib protrusion 52 is shorter than the length of the second region 73. The length of the first region 72 is preferably shorter than half the length of the rib protrusion 52, more preferably shorter than one-third the length of the rib protrusion 52, and most preferably shorter than one-quarter the length of the rib protrusion 52.

[0029] 7, the first region 72 is configured to protrude further toward the inner surface 34a of the wing wall 34 than the second region 73. That is, the distance L from the opening 58 formed in the first region 72 to the inner surface 34a is １ is the distance L from the opening 58 formed in the second region 73 to the inner surface 34a. ２ The angle formed by the boundary region 74 with respect to the first region 72 is θ １ The angle formed by the boundary region 74 with respect to the second region 73 is θ ２ Then, the angle θ １ The range is 180°<θ １ ≦270°, and the angle θ ２ The range is 90°≦θ ２ <180°.

[0030] 7, the discharge hole 64 is formed near the tip-side edge 34b of the wing wall 34, and therefore the recovery passage 63 is defined between the outer surface 59a1 of the insert body 59a and the inner surface 34a of the wing wall 34, and also between the tip-side edge 34b of the wing wall 34 and the tip-side end 52c of the ridge 52 in the longitudinal direction of the ridge 52. If the discharge hole 64 is formed near the hub-side edge 34c of the wing wall 34 (see FIG. 2), the recovery passage 63 is defined between the outer surface 59a1 of the insert body 59a and the inner surface 34a of the wing wall 34, and also between the hub-side edge 34c of the wing wall 34 and the hub-side end 52d of the ridge 52 (see FIG. 6) in the longitudinal direction.

[0031] The outer surface 54b of the end 52c facing the recovery channel 63 includes a first connecting edge 54b1 connecting to the outer surface 59a1 of the insert body 59a and a second connecting edge 54b2 connecting to the opposing surface 71. The first connecting edge 54b1 and the second connecting edge 54b2 are located farther toward the hub-side edge 34c (see FIG. 2) than the tip-side edge 34b of the wing wall 34 in the longitudinal direction of the protrusion 52, and the outer surface 54b is flat. With this configuration, the recovery channel 63 is formed between the tip-side edge 34b and the end 52c in the longitudinal direction of the protrusion 52. The first connecting edge 54b1 may be located at the same position as the tip-side edge 34b in the longitudinal direction. That is, of the first connecting edge 54b1 and the second connecting edge 54b2, at least the second connecting edge 54b2 may be positioned further toward the hub side edge 34c than the tip side edge 34b of the wing wall 34 in the longitudinal direction of the ridge 52.

[0032] <Cooling Operation of Blade Wall in Turbine Blade According to Embodiment 1 of the Present Disclosure> The cooling operation of the blade wall in the turbine blade according to Embodiment 1 of the present disclosure will be described. As shown in FIG. 2 , a cooling medium (e.g., cooling air) is supplied from the outside of the stator blade 24 to the inside of the blade wall 34 via a path 37. As shown in FIG. 3 , the cooling medium flows into each of the internal cavities 56 a and 56 b inside the blade wall 34. For example, as shown in FIG. 5 , the cooling medium that flows into the internal cavity 56 a flows into the flow passage 54 and then flows into the cooling holes 55 and is ejected from the openings 58 toward the inner surface 34 a of the blade wall 34. The cooling medium ejected from the cooling holes 55 collides with the inner surface 34 a of the blade wall 34, thereby cooling the blade wall 34. After colliding with the inner surface 34 a of the blade wall 34, the cooling medium is introduced into a recovery space 53 defined between adjacent ridges 52.

[0033] 4 , the cooling medium introduced into the recovery spaces 53 flows within the recovery spaces 53 toward the recovery passages 63 and then flows from the recovery spaces 53 into the recovery passages 63. The cooling medium that has flowed within each recovery space 53 joins together within the recovery passages 63 and flows out of the recovery passages 63 via the discharge holes 64. The cooling medium that has flowed out of the recovery passages 63 flows through the supply path 62 and then flows into the shroud circumferential passage 60 via the supply port 61. The cooling medium that has flowed into the shroud circumferential passage 60 flows through the shroud circumferential passage 60 and then flows out of the shroud circumferential passage 60 via the discharge port 65 to the outside of the stator blade 24.

[0034] If a cross flow occurs, in which the cooling medium flows in a direction along the inner surface 34 a near the other openings 58 after colliding with the inner surface 34 a of the blade wall 34, the cooling medium ejected from the other openings 58 may be interfered with by the cross flow, which may result in a decrease in cooling efficiency. In contrast, in the stator vane 24 having the above-described configuration, the cooling medium is introduced into the recovery space 53 after colliding with the inner surface 34 a of the blade wall 34, which reduces the cross flow and, as a result, reduces the risk of a decrease in the cooling efficiency of the blade wall 34.

[0035] However, in the above-described configuration, if there is a cross flow that is not introduced into the recovery space 53, the cooling medium in the recovery passage 63 flows out of the blade wall 34 through the discharge holes 64, causing the cross flow to become locally large in a region close to the discharge holes 64 in the longitudinal direction of the ridge 52. As a result, the cooling medium ejected from the openings 58 of the cooling holes 55 in the region close to the discharge holes 64 in the longitudinal direction of the ridge 52 is interfered with by the locally large cross flow (for example, the flow of the ejected cooling medium is bent), thereby reducing the cooling efficiency of the blade wall 34.

[0036] In contrast, in the first embodiment, as shown in FIG. 7, in each protrusion 52, the distance L from the opening 58 formed in the first region 72 to the inner surface 34a is １ is the distance L from the opening 58 formed in the second region 73 to the inner surface 34a. ２In this case, in the region close to the discharge hole 64 in the longitudinal direction of the protrusion 52, i.e., in the first region 72, the distance L from the opening 58 to the inner surface 34a is smaller than １ Since the cross flow is small, the cooling medium ejected from the openings 58 in the first region 72 can collide with the inner surface 34a of the blade wall 34 before the flow of the cooling medium is bent by the cross flow. In other words, the influence of the cooling medium ejected from the openings 58 in the first region 72 being bent by the cross flow can be suppressed, and therefore the adverse effect of a locally large cross flow on the cooling effect of the blade wall 34 can be suppressed.

[0037] The cross flow flowing between the second region 73 and the inner surface 34a of the blade wall 34 in the direction toward the first region 72 collides with the boundary region 74, changes direction along the boundary region 74, and flows into the recovery spaces 53 (see FIGS. 3 to 6 ) on both sides of the protrusion 52. As a result, the cross flow flowing between the first region 72 and the inner surface 34a of the blade wall 34 is reduced, thereby weakening the influence of the cross flow on the flow of the cooling medium ejected from the openings 58 in the first region 72. Furthermore, the cooling medium that has flowed through each recovery space 53 joins together in the recovery passage 63 and flows out of the recovery passage 63 via the discharge holes 64, making it easier for the cooling medium that has cooled the blade wall 34 to flow out of the interior of the blade wall 34.

[0038] <Modification of the Turbine Blade According to the First Embodiment of the Present Disclosure> In the first embodiment, the boundary region 74 is a flat surface. However, it may be a curved surface that is concave toward the first region 72. Furthermore, as shown in FIG. 8 , the boundary region 74 may have a configuration in which both end edges 74 c, 74 d of the boundary region 74 in a direction perpendicular to the longitudinal direction of the rib protrusion 52 (the width direction of the rib protrusion 52) protrude toward the second region 73. In this configuration, the boundary region 74 has a protruding edge 74 e between the end edges 74 c and 74 d in the width direction of the rib protrusion 52, and has a first surface 74 f and a second surface 74 g on both sides of the protruding edge 74 e in the width direction of the rib protrusion 52. When the boundary region 74 has such a configuration, a cross flow flowing along the second region 73 toward the boundary region 74 (in the direction of arrow A) collides with the protruding edge 74 e, thereby splitting into flows on both sides of the protruding edge 74 e (arrows B and C). One of the divided cross flows (arrow B) flows along the first surface 74 f, and the other (arrow C) flows along the second surface 74 g, thereby flowing into the recovery spaces 53, 53 on both sides of the ridge 52 (arrows D and E). As a result, the cross flow flowing between the first region 72 and the inner surface 34 a of the blade wall 34 is reduced, and the effect of the cross flow on the flow of the coolant ejected from the opening 58 in the first region 72 can be weakened.

[0039] (Embodiment 2) Next, a turbine blade according to Embodiment 2 of the present disclosure will be described. Although Embodiment 2 has been described as having a configuration independent of that of Embodiment 1, it may have the configuration of Embodiment 2 described below, based on the configurations of Embodiment 1 and its modified examples. In Embodiment 2, the same components as those of Embodiment 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0040] 9 , in the first region 72 on the opposing surface 71 of the rib 52, the opening 58a of the first cooling hole 55a and the opening 58 located adjacent to the opening 58a are formed, as in the exemplary configuration of the first embodiment. The number of openings 58 in the first region 71 is not limited to two, as in the first embodiment. The second embodiment may be configured such that the first region 72 does not protrude further toward the inner surface 34a of the blade wall 34 (see FIGS. 3 to 5 ) than the second region 73, and the first and second regions 72 and 73 are flush with each other (as described above, the second embodiment may have the configurations of the first embodiment and its modified examples). In this configuration, the boundary region 74 is not a surface as in the first embodiment, but rather a boundary line extending in the width direction of the rib 52.

[0041] In the second embodiment, the opening area of ​​each of the openings 58 formed in the first region 72 is larger than the opening area of ​​each of the openings 58 formed in the second region 73. Although circular openings 58 are depicted in Fig. 9, the openings 58 are not limited to being circular, and may be ellipses that are elongated in the longitudinal direction or width direction of the protrusion, or in any direction between these, or may be polygonal, irregular, or have any other shape. Furthermore, the shapes of all the openings do not have to be the same, and at least some of the openings may have different shapes.

[0042] <Cooling Operation of Blade Wall in Turbine Blade According to Embodiment 2 of the Present Disclosure> The cooling operation of the blade wall in the turbine blade according to Embodiment 2 of the present disclosure is basically the same as that of Embodiment 1. The operation differs from Embodiment 1 in that the opening area of ​​the openings 58 formed in the first region 72 is larger than the opening area of ​​the openings 58 formed in the second region 73, and therefore the flow rate of the coolant ejected from the openings 58 in the first region 72 is larger than the flow rate of the coolant ejected from the openings 58 in the second region 73. As a result, even if the cross flow between the first region 72 and the inner surface 34 a is locally large and there is a risk of a decrease in the cooling efficiency of the blade wall 34, the risk of a decrease in cooling efficiency can be compensated for by the increase in the flow rate of the coolant ejected toward the inner surface 34 a opposite the first region 72. Therefore, the adverse effect of the locally large cross flow on the cooling effect of the blade wall 34 can be suppressed.

[0043] In the first embodiment, the distance between the first region 72 and the inner surface 34a of the blade wall 34 is reduced to prevent the crossflow from becoming locally large between the first region 72 and the inner surface 34a, allowing the coolant ejected from the openings 58 in the first region 72 to collide with the inner surface 34a before being deflected by the crossflow. In the second embodiment, the opening area of ​​the openings 58 formed in the first region 72 is increased to increase the flow rate of the ejected coolant, thereby compensating for the risk of a decrease in the cooling efficiency of the blade wall 34 due to the locally large crossflow. On the other hand, in the configuration of the second embodiment, due to the difference in the opening areas of the openings 58 in the first region 72 and the openings 58 in the second region 73, the cross-sectional area of ​​the coolant flow ejected from the openings 58 in the first region 72, taken in a direction perpendicular to the flow direction, is larger than that of the coolant flow ejected from the openings 58 in the second region 73. This may result in an advantageous effect that the coolant flow ejected from the openings 58 in the first region 72 is less likely to be deflected by the crossflow. The above-described effects of the first embodiment and the latter of the two effects of the second embodiment are common in that they make it difficult for the coolant ejected from the openings 58 in the first region 72 to bend due to crossflow before it collides with the inner surface 34 a. Such effects can be appropriately obtained by adjusting the indexes described below.

[0044] When the opening 58 formed in the first region 72 is regarded as a circle, the diameter D is calculated from the opening area of ​​the opening 58. １ and the distance L from the opening 58 formed in the first region 72 to the inner surface 34a of the wing wall 34. １ (See Figure 7) １ / D １ may be adjusted as the above-mentioned index. １ / D １ and a similar ratio L for the opening 58 formed in the second region 73. ２ / D ２ (D ２(where x is the diameter calculated from the opening area of ​​opening 58 when opening 58 formed in second region 73 is considered to be a circle.) By controlling this ratio, when both the opening area of ​​opening 58 and the distance from opening 58 to inner surface 34 a are made different between first region 72 and second region 73, it is possible to design a configuration that reliably achieves the above-described effects.

[0045] (Embodiment 3) Next, a turbine blade according to Embodiment 3 of the present disclosure will be described. Although Embodiment 3 has been described as having a configuration independent of the configurations of Embodiments 1 and 2, it may have the configuration of Embodiment 3 described below, based on the configurations of Embodiments 1 and 2 and their modified examples. In Embodiment 3, the same components as those of Embodiments 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0046] <Configuration of turbine blade according to embodiment 3 of the present disclosure> As shown in FIG. 10 , in the rib protrusion 52, the width W １ is the width W of the protrusion 52 in the second region 73 ２ As a result, the width W of the recovery space 53 formed between the first regions 72a and 72b is ３ is the width W of the recovery space 53 formed between the second regions 73a and 73b. ４ becomes larger than

[0047] <Cooling Operation of Blade Wall in Turbine Blade According to Third Embodiment of the Present Disclosure> The cooling operation of the blade wall in the turbine blade according to the third embodiment of the present disclosure is basically the same as that in the first embodiment. The operation different from the first embodiment is that the width W of the recovery space 53 formed between the first regions 72 a and 72 b is ３ The width W of the recovery space 53 formed between the second regions 73a and 73b is ４Since the cross flow between the first region 72 and the inner surface 34a of the blade wall 34 is larger than the cross flow between the second region 73 and the inner surface 34a of the blade wall 34 (see FIGS. 3 to 5), the cross flow is more likely to enter the recovery space 53. Due to this difference, the cross flow between the first region 72 and the inner surface 34a of the blade wall 34 can be reduced, and the adverse effect of a locally large cross flow on the cooling effect of the blade wall 34 can be suppressed.

[0048] (Fourth embodiment) Next, a turbine blade according to a fourth embodiment of the present disclosure will be described. Although the fourth embodiment has been described as having a configuration independent of the configurations of the first to third embodiments, the fourth embodiment may have the configuration of the fourth embodiment described below, based on the configurations of the first to third embodiments and their modified examples. In the fourth embodiment, the same components as those of the first to third embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

[0049] <Configuration of a turbine blade according to a fourth embodiment of the present disclosure> As shown in Fig. 11 , in a first region 72 of the rib protrusion 52, both end edges 71c, 71d of the opposing surface 71 in the width direction of the rib protrusion 52 are chamfered. The both end edges 71c, 71d need only be chamfered in at least the first region 72, but the boundary region 74 (see Figs. 6 and 7 ) and the second region 73 (see Figs. 6 and 7 ) may also be chamfered. That is, all of the both end edges of the rib protrusion 52 may be chamfered. The chamfering is not limited to a chamfered shape having a curved cross section as shown in Fig. 11 , but may also be a chamfered shape having a linear cross section as shown in Fig. 12 .

[0050] <Cooling Operation of Blade Walls in Turbine Blade According to Embodiment 4 of the Present Disclosure> The cooling operation of blade walls in a turbine blade according to Embodiment 4 of the present disclosure is basically the same as that of Embodiment 1. The operation differs from Embodiment 1 in that, because both end edges 71 c, 71 d of the first region 72 of the opposing surface 71 in the width direction of the protrusion 52 are chamfered, the cross flow flowing between the first region 72 and the inner surface 34 a of the blade wall 34 is more likely to flow into the recovery space 53 than when both end edges 71 c, 71 d are not chamfered. This difference makes it possible to reduce the cross flow flowing between the first region 72 and the inner surface 34 a of the blade wall 34, thereby suppressing the adverse effect of a locally large cross flow on the cooling effect of the blade wall 34.

[0051] (Embodiment 5) Next, a turbine blade according to Embodiment 5 of the present disclosure will be described. Although Embodiment 5 has been described as having a configuration independent of the configurations of Embodiments 1 to 4, it may have the configuration of Embodiment 5 described below, based on the configurations of Embodiments 1 to 4 and their modified examples. In Embodiment 5, the same components as those of Embodiments 1 to 4 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0052] Configuration of a turbine blade according to a fifth embodiment of the present disclosure As shown in Figure 13 , among the openings 58 in the first region 72 of the rib protrusion 52, the opening farthest from the discharge hole 64 (see Figure 4 ) in the longitudinal direction of the rib protrusion 52 is designated as opening 58b, and among the openings 58 in the second region 73, the opening closest to the discharge hole 64 in the longitudinal direction of the rib protrusion 52 is designated as opening 58c. Note that if only one opening, opening 58a, is formed in the first region 72, opening 58a is designated as opening 58b. A rectangular, plate-shaped protrusion 80 is provided on the opposing surface 71 of the rib protrusion 52 between openings 58b and 58c. The plate-shaped protrusion 80 has a surface 80a that faces the first region 72 when viewed from the second region 73 in the longitudinal direction of the rib protrusion 52. When the protrusion 80 is rectangular and plate-shaped, it is preferable that the surface 80a be perpendicular to both the opposing surface 71 and the longitudinal direction of the protrusion 52, but it is not limited to being strictly perpendicular, and it is sufficient if it is approximately perpendicular.

[0053] <Cooling Operation of Blade Wall in Turbine Blade According to Embodiment 5 of the Present Disclosure> The cooling operation of the blade wall in the turbine blade according to Embodiment 5 of the present disclosure is basically the same as that of Embodiment 1. The operation different from that of Embodiment 1 is that the cooling operation of the blade wall is performed by cooling the blade wall between the second region 73 and the inner surface 34 a of the blade wall 34 in the direction toward the first region 72 (indicated by arrow F １ ) collides perpendicularly with the surface 80a. When the cross flow collides perpendicularly with the surface 80a, the cross flow flows in a direction along the surface 80a (arrow G １ and H １ ) and flows into the recovery spaces 53 on both sides of the ridges 52. As a result, the cross flow between the first region 72 and the inner surface 34a of the blade wall 34 is reduced, and the influence of the cross flow on the flow of the coolant ejected from the openings 58 in the first region 72 can be weakened. This makes it possible to suppress the adverse influence of a locally large cross flow on the cooling effect of the blade wall 34.

[0054] <Modification of the turbine blade according to the fifth embodiment of the present disclosure> The protrusion 80 is not limited to a rectangular and plate-shaped configuration. The protrusion 80 may have any shape as long as it has a surface 80a that faces the first region 72 when viewed from the second region 73 in the longitudinal direction of the rib protrusion 52. Note that "facing" does not necessarily mean being perpendicular to the longitudinal direction of the rib protrusion 52, but rather the surface 80a may be visible when the protrusion 80 is viewed in the above-mentioned direction. For example, as shown in FIG. 14 , the protrusion 80 may have a configuration in which both end edges 80b, 80c of the protrusion 80 in the width direction of the rib protrusion 52 protrude toward the second region 73. In this configuration, the surface 80a has a protruding edge 80d between the end edge 80b and the end edge 80c in the width direction of the rib protrusion 52, and a first surface 80a1 and a second surface 80a2 are provided on both sides of the protruding edge 80d in the width direction of the rib protrusion 52. When the protrusion 80 has such a configuration, the direction of the protrusion 80 along the second region 73 (arrow F ２ The cross flow (flowing in the direction of arrow G) collides with the protruding edge 80d, and splits into flows on both sides of the protruding edge 80d. ２ and H ２ One of the divided cross flows (arrow G ２) flows along the first surface 80a1, and the other (arrow H ２ ) flows along the second surface 80a2 and enters the recovery spaces 53, 53 on both sides of the ridge 52. As a result, the cross flow between the first region 72 and the inner surface 34a of the blade wall 34 is reduced, and the influence of the cross flow on the flow of the coolant ejected from the opening 58 in the first region 72 can be weakened.

[0055] Furthermore, as shown in FIG. 15 , the protrusion 80 may be formed from two plates 81, 81 in the shape of a right triangle. Each plate 81 includes a front surface 81a, which is one side of the right triangle, and a back surface 81b, which is the other side of the right triangle. A slope 82 is defined between the hypotenuses 81a1 and 81b1 on the front surface 81a and back surface 81b of each plate 81. The two plates 81, 81 are arranged so that each slope 82 faces the second region 73 in the longitudinal direction of the protrusion 52, and the distance between the two slopes 82, 82 in the width direction of the protrusion 52 decreases in the direction from the second region 73 toward the first region 72 when the protrusion 80 is viewed toward the opposing surface 71. In this configuration, the front surface 81a of each plate 81 corresponds to the surface 80a. When the protrusion 80 has such a configuration, a surface 81a of each plate 81 corresponds to the surface 80a. ...b of the protrusion 80 is formed along the second region 73 toward the protrusion 80 (as indicated by the arrow F). ３ The cross flow (flowing in the direction of the arrows 58 and 59) forms a flow (vortex) that crosses over each plate 81 and flows into the recovery spaces 53, 53 on both sides of the ridge 52. As a result, the cross flow that flows between the first region 72 and the inner surface 34a of the blade wall 34 is reduced, and the effect of the cross flow on the flow of the coolant ejected from the openings 58 in the first region 72 can be weakened.

[0056] When the protrusion 80 is provided on the premise of the configuration of the first embodiment and its modified examples, the protrusion 80 may be provided in the first region 72 or the second region 73. １ (see FIG. 7) is relatively small and the angle θ ２ (see FIG. 7) is a relatively large value, the protrusion 80 can be provided in the boundary region 74. Furthermore, without assuming the configurations of the first embodiment and its modified examples, the angle θ １ (See Figure 7) and angle θ ２(see FIG. 7) can be both 180° and a protrusion 80 can be provided in the boundary region 74.

[0057] Sixth Embodiment Next, a turbine blade according to a sixth embodiment of the present disclosure will be described. Although the sixth embodiment has been described as having a configuration independent of the configurations of the first to fifth embodiments, the sixth embodiment may have the configuration of the sixth embodiment described below, based on the configurations of the first to fifth embodiments and their modified examples. In the sixth embodiment, the same components as those of the first to fifth embodiments are designated by the same reference numerals, and detailed description thereof will be omitted.

[0058] 16 , the inner end surface 54a is the surface that faces the flow path 54 in the ridge 52 when viewed in the longitudinal direction of the ridge 52 toward the recovery flow path 63. The inner end surface 54a includes, in the direction from the internal cavity 56 toward the opposing surface 71, a first edge 54a1 that is the edge on the internal cavity 56 side and a second edge 54a2 that is the edge on the opposing surface 71 side. The inner end surface 54a is configured to move away from the discharge hole 64 in the longitudinal direction of the ridge 52 as it moves from the first edge 54a1 toward the second edge 54a2.

[0059] The inner end surface 54a may have any shape as long as it has these characteristics. For example, as shown in FIG. 16 , the inner end surface 54a may be a curved surface that protrudes toward the opposite side from the recovery channel 63 in the longitudinal direction of the rib protrusion 52. When the inner end surface 54a is a curved surface like this, the outer surface 54b of the end 52c of the rib protrusion 52 may also be a curved surface that protrudes in the longitudinal direction of the rib protrusion 52 in a direction away from the discharge hole 64, similar to the inner end surface 54a. When the outer surface 54b is a curved surface like this, even in the sixth embodiment, if at least the second connecting edge 54b2 of the first connecting edge 54b1 and the second connecting edge 54b2 is positioned closer to the hub-side edge 34c (see FIG. 2 ) than the tip-side edge 34b of the wing wall 34 in the longitudinal direction of the rib protrusion 52, the recovery channel 63 is formed between the tip-side edge 34b and the end 52c in the longitudinal direction. As shown in FIG. 17, the inner end surface 54a may be a flat surface from the first edge 54a1 to the second edge 54a2, or as shown in FIG. 18, the inner end surface 54a may have a configuration in which the cross sections of the first edge 54a1 and the second edge 54a2 are changed to curved shapes compared to the configuration in FIG. 17.

[0060] Cooling Operation of Blade Walls in a Turbine Blade According to Embodiment 6 of the Present Disclosure The cooling operation of blade walls in a turbine blade according to Embodiment 6 of the present disclosure is basically the same as that in Embodiment 1. In Embodiment 1, as shown in FIG. 7 , the inner end surface 54a is perpendicular to the longitudinal direction of the rib 52, so the boundary between the inner surface 56a defining the internal cavity 56 and the inner end surface 54a, i.e., the first edge 54a1, has a right-angled cross-sectional shape. Therefore, when the coolant flows from the internal cavity 56 into the flow passage 54, separation is likely to occur at the first edge 54a1. In contrast, in the configurations of Embodiment 6 shown in FIGS. 16 and 18 , the first edge 54a1 has a curved, smooth shape, so separation is unlikely to occur at the first edge 54a1 when the coolant flows from the internal cavity 56 into the flow passage 54. In addition, in the configuration of Figure 17, the angle of the cross-sectional shape of the first edge 54a1 is greater than 90°, so peeling is less likely to occur at the first edge 54a1 when the coolant flows from the internal cavity 56 into the flow path 54.

[0061] In this way, the risk of the cooling medium flow separating when it flows from the internal cavity 56 into the flow path 54 can be reduced, thereby reducing the risk of a decrease in the flow rate of the cooling medium ejected from the opening 58 of the cooling hole 55, and suppressing the adverse effects on the cooling effect of the blade wall 34.

[0062] <Modifications of the turbine blade according to the first to sixth embodiments of the present disclosure> The configuration in which the recovery passage 63 is formed in the blade wall 34 is not limited to the configuration in which the ribs 52 have the configurations of the first to sixth embodiments. Even if the ribs 52 have any configuration other than the configurations of the first to sixth embodiments, the provision of the recovery passage 63 can make it easier for the cooling medium that has cooled the blade wall 34 to flow out from the interior of the blade wall 34. Furthermore, the configurations of the second to fifth embodiments do not necessarily assume a configuration in which the first region 72 on the opposing surface 71 of each rib 52 protrudes more toward the inner surface 34a of the blade wall 34 than the second region 73. A configuration in which the first region 72 does not protrude more toward the inner surface 34a of the blade wall 34 than the second region 73 and the first region 72 and the second region 73 are on the same plane may also be realized.

[0063] In Figure 4, the supply path 62 connecting the discharge hole 64 and the supply port 61 is depicted as having a certain length, but the length is arbitrary and may be shorter than the length of the supply path 62 shown in Figure 4, or, for example, as shown in Figure 19, the supply path 62 may not exist and the discharge hole 64 and the supply port 61 may be directly connected.

[0064] The contents described in each of the above embodiments can be understood, for example, as follows.

[0065] [1] A turbine blade according to one aspect is a turbine blade (stator blade 24 / rotor blade 26) comprising: a blade wall (34); and an insert (51) inserted into a space (50) formed inside the blade wall (34), wherein an internal cavity (56) communicating with the outside of the turbine blade (24 / 26) is formed inside an insert body portion (59) of the insert (51), and a plurality of ridges (52) are formed on an outer surface (59a1, 59b1) of the insert body portion (59) so as to protrude toward an inner surface (34a) of the blade wall (34) and have opposing surfaces (71) opposing the inner surface (34a) of the blade wall (34), and each of the plurality of ridges (52) has a flow path (54) communicating with the internal cavity (56), a plurality of cooling holes (55) that communicate with the flow passages (54), that open in the opposing surface (71), and that are aligned along the longitudinal direction of each of the plurality of ridges (52), wherein a recovery space (53) is defined between two adjacent ridges (55, 55) of the plurality of ridges (52), and a recovery flow passage (63) that communicates with the recovery space (53) is defined between the outer surface (59a1, 59b1) of the insert body portion (59) and the inner surface (34a) of the blade wall (34), and between a hub-side edge (34c) of the blade wall (34) and a hub-side end (52d) of the ridge (52) or between a tip-side edge (34b) of the blade wall (34) and a tip-side end (52c) of the ridge (52), The blade wall (34) is formed with a discharge hole (64) that connects the recovery passage (63) with the outside of the turbine blade (24 / 26).

[0066] According to the turbine blade of the present disclosure, the cooling medium that has circulated through each recovery space joins together within the recovery flow path and flows out of the recovery flow path through the discharge hole, making it easier for the cooling medium that has cooled the blade wall to flow out from inside the blade wall.

[0067] [2] A turbine blade according to another aspect is the turbine blade of [1], wherein, of the two longitudinal end portions (52c, 52d) of each of the plurality of ridges (52), the outer surface (54b) of the end portion (52c, 52d) facing the recovery passage (63) includes a first connecting edge (54b1) connected to the outer surface (59a1, 59b1) of the insert body portion (59) and a second connecting edge (54b2) connected to the opposing surface (71), and at least the second connecting edge (54b2) of the first connecting edge (54b1) and the second connecting edge (54b2) is located in a position farther away from the hub-side edge (34c) of the blade wall (34) toward the tip-side edge (34b) of the blade wall (34) in the longitudinal direction, or in a position farther away from the tip-side edge (34b) toward the hub-side edge (34c), The outer surface (54b) is a surface that is curved so as to be recessed toward the opposite side to the recovery channel (63) in the longitudinal direction.

[0068] With this configuration, a recovery flow path is formed between the tip side edge and the end portion or between the hub side edge and the end portion in the longitudinal direction of the protrusion.

[0069] [3] A turbine blade according to yet another aspect is the turbine blade of [1], wherein, of the two longitudinal end portions (52c, 52d) of each of the plurality of ridges (52), the outer surface (54b) of the end portion (52c, 52d) facing the recovery passage (63) includes a first connecting edge (54b1) connected to the outer surface (59a1, 59b1) of the insert body portion (59) and a second connecting edge (54b2) connected to the opposing surface (71), and at least the second connecting edge (54b2) of the first connecting edge (54b1) and the second connecting edge (54b2) is located in a position farther away from the hub-side edge (34c) of the blade wall (34) toward the tip-side edge (34b) of the blade wall (34) in the longitudinal direction, or in a position farther away from the tip-side edge (34b) toward the hub-side edge (34c), The outer surface (54b) is a flat surface.

[0070] With this configuration, a recovery flow path is formed between the tip side edge and the end portion or between the hub side edge and the end portion in the longitudinal direction of the protrusion.

[0071] [4] A turbine blade according to yet another embodiment is the turbine blade of any one of [1] to [3], wherein a shroud peripheral flow passage (60) extending along the periphery is formed in one of the outer shroud (38) and the inner shroud (40) provided on the tip side edge (34b) and the hub side edge (34c) of the blade wall (34), respectively, and the recovery flow passage (63) communicates with the shroud peripheral flow passage (60) via the discharge hole (64).

[0072] According to this configuration, the cooling medium that flows out of the recovery passage through the discharge hole flows through the shroud peripheral passage, and then flows out of the shroud peripheral passage to the outside of the stator blade through the discharge port formed in the shroud peripheral passage, thereby making it easier for the cooling medium that has cooled the blade wall to flow out from inside the blade wall.

[0073] [5] A turbine blade according to yet another aspect is the turbine blade of any of [1] to [4], wherein, in each of the plurality of ridges (52), if the cooling hole (55) formed at a position closest to the discharge hole (64) in the longitudinal direction among the plurality of cooling holes (55) is defined as a first cooling hole (55a), a first region (72) of the opposing surface (71) including at least an opening (58a) of the first cooling hole (55a) protrudes toward the inner surface (34a) of the blade wall (34) more than second regions (73) of the opposing surface (71) including openings (58) of other cooling holes (55).

[0074] According to the turbine blade of the present disclosure, the cross flow may become locally large in a region close to the discharge hole in the longitudinal direction of each of the multiple protrusions. However, the first region of the opposing surface, which includes the opening of the first cooling hole that is formed closest to the discharge hole among the multiple cooling holes formed in each of the multiple protrusions, protrudes more toward the inner surface of the blade wall than the second region of the opposing surface, which includes the openings of the other cooling holes. As a result, the cooling medium ejected from the opening in the first region can collide with the inner surface of the blade wall before the flow of the cooling medium is bent by the cross flow, thereby suppressing the adverse effects that the locally large cross flow has on the cooling effect of the blade wall of the turbine blade.

[0075] [6] Another aspect of the turbine impeller is the turbine impeller of any one of [1] to [5], wherein, if the surfaces facing each other inside the flow paths (54) of the plurality of ridges (52) when viewed in the longitudinal direction toward the recovery flow path (63) are defined as internal end faces (54a), the internal end faces (54a) include, in a direction from the internal cavity (56) toward the opposing surface (71), a first edge (54a1) that is the edge on the internal cavity (56) side, and a second edge (54a2) that is the edge on the opposing surface (71), and the internal end faces (54a) are configured to move away from the discharge holes (64) in the longitudinal direction as they move from the first edge (54a1) toward the second edge (54a2).

[0076] If the internal end face is perpendicular to the longitudinal direction of the rib, when the cooling medium flowing through the internal cavity enters the flow passage within the rib, the flow of the cooling medium is likely to separate at the boundary between the internal cavity and the flow passage, causing the flow of the cooling medium within the flow passage to become turbulent and potentially reducing the flow rate of the cooling medium ejected from the opening of the cooling hole. In contrast, the configuration [6] reduces the risk of the cooling medium flow separating when the cooling medium flows from the internal cavity into the flow passage, thereby reducing the risk of a reduction in the flow rate of the cooling medium ejected from the opening of the cooling hole and suppressing adverse effects on the cooling effect of the turbine blade wall.

[0077] [7] A turbine blade according to yet another aspect is the turbine blade of [5], wherein a boundary region (74) connecting the first region (72) and the second region (73) is formed in each of the plurality of ridges (52), and the angle formed by the boundary region (74) with respect to the first region (72) is defined as θ １ The angle formed by the boundary region (74) with respect to the second region (73) is θ ２ Then, 180°<θ １ ≦270° and 90°≦θ ２ <180°.

[0078] With this configuration, the direction of the crossflow changes when it flows from the second region to the first region, thereby reducing the effect of the crossflow on the cooling medium ejected from the opening in the first region, thereby reducing the adverse effect that a locally large crossflow has on the cooling effect of the turbine blade wall.

[0079] [8] A turbine blade according to yet another aspect is the turbine blade of any one of [1] to [7], wherein, when a cooling hole formed in a position closest to the discharge hole (64) in the longitudinal direction among the plurality of cooling holes (55) is defined as a first cooling hole (55a), each of the plurality of ridges (52) includes: a first region (72) of the opposing surface (71) including at least an opening (58a) of the first cooling hole (55a); and a second region (73) of the opposing surface (71) including openings (58) of other cooling holes (55), In each of the plurality of protrusions (52), a protrusion (80) including a surface (80a) that faces each other when the first region (72) is viewed from the second region (73) in the longitudinal direction is provided between an opening (58b) formed at a position farthest from the discharge hole (64) in the longitudinal direction among at least one opening (58) in the first region (72) and an opening (58c) formed at a position closest to the discharge hole (64) in the longitudinal direction among at least one opening (58) in the second region (73).

[0080] With this configuration, when the cross-flow flows from the second region into the first region, it hits the protrusion and changes direction, thereby reducing the effect of the cross-flow on the cooling medium ejected from the opening in the first region, thereby reducing the adverse effect that locally large cross-flow has on the cooling effect of the turbine blade wall.

[0081] [9] A turbine vane according to yet another aspect is the turbine vane according to any one of [1] to [8], wherein, if a cooling hole formed in a position closest to the discharge hole (64) in the longitudinal direction among the plurality of cooling holes (55) is defined as a first cooling hole (55a), each of the plurality of ridges (52) includes a first region (72) of the opposing surface (71) including at least an opening (58a) of the first cooling hole (55a), and a second region (73) of the opposing surface (71) including openings (58) of other cooling holes (55), and an opening area of ​​the opening (58) in the first region (72) is larger than an opening area of ​​the opening (58) in the second region (73).

[0082] With this configuration, the flow rate of the cooling medium ejected from the opening in the first region is greater than the flow rate of the cooling medium ejected from the opening in the second region. Therefore, even if the cross-flow between the first region and the inner surface is locally large and there is a risk of a decrease in the cooling efficiency of the blade wall, the increase in the flow rate of the cooling medium ejected toward the inner surface opposite the first region can compensate for the risk of a decrease in cooling efficiency. Furthermore, the cross-sectional area of ​​the flow of the cooling medium ejected from the opening in the first region, when cut in a direction perpendicular to the flow direction, is larger than that of the flow of the cooling medium ejected from the opening in the second region, and therefore the flow is less likely to bend by the cross-flow, thereby suppressing the adverse effects of a locally large cross-flow on the cooling effect of the blade wall of the turbine blade.

[0083]

[10] A turbine blade according to yet another aspect is the turbine blade of any one of [1] to [9], wherein, when a cooling hole formed in a position closest to the discharge hole (64) in the longitudinal direction among the plurality of cooling holes (55) is defined as a first cooling hole (55a), each of the plurality of ridges (52) includes: a first region (72) of the opposing surface (71) including at least an opening (58a) of the first cooling hole (55a); and a second region (73) of the opposing surface (71) including an opening (58) of another cooling hole (55), and when a length of each of the plurality of ridges (52) in a direction perpendicular to the longitudinal direction is defined as a width, a width (W) of a portion of each of the plurality of ridges (52) including the first region (72) is １ ) is the width (W) of the portion including the second region (73). ２ ) is smaller than

[0084] With this configuration, the width of the recovery space between the first regions of adjacent ridges is greater than the width of the recovery space between the second regions of adjacent ridges, making it easier for crossflow flowing between the first region and the inner surface of the blade wall to flow into the recovery space, thereby suppressing the adverse effect that locally large crossflow has on the cooling effect of the blade wall of the turbine blade.

[0085]

[11] A turbine blade according to yet another aspect is the turbine blade of any one of [1] to

[10] , wherein, in each of the plurality of ridges (52), both end edges (71c, 71d) of the opposing surface (71) in a direction perpendicular to the longitudinal direction are chamfered.

[0086] With this configuration, the cross flow is more likely to flow into the recovery space than when both end edges of the opposing surface are not chamfered, thereby suppressing the adverse effects that locally large cross flow has on the cooling effect of the turbine blade wall.

[0087]

[12] A turbine vane according to yet another aspect is the turbine vane according to any one of [1] to

[10] , wherein, when a cooling hole formed in a position closest to the discharge hole (64) in the longitudinal direction among the plurality of cooling holes (55) is defined as a first cooling hole (55a), each of the plurality of ridges (52) includes: a first region (72) of the opposing surface (71) including at least an opening (58a) of the first cooling hole (55a); and a second region (73) of the opposing surface (71) including openings (58) of other cooling holes (55), and in the first region (72) of each of the plurality of ridges (52), both end edges (71c, 71d) of the opposing surface (71) in a direction perpendicular to the longitudinal direction are chamfered.

[0088] With this configuration, the cross flow is more likely to flow into the recovery space than when both end edges of the first region of the opposing surface are not chamfered, thereby suppressing the adverse effects that locally large cross flow has on the cooling effect of the turbine blade wall.

[0089]

[13] A turbine blade according to yet another aspect is the turbine blade of [7], wherein the boundary region (74) protrudes from both end edges (74c, 74d) of the boundary region (74) in a direction perpendicular to the longitudinal direction toward the second region (72).

[0090] With this configuration, the cross flow flows along the boundary region and flows into the recovery spaces on both sides of the protrusion, thereby reducing the cross flow that flows between the first region and the inner surface of the blade wall, thereby suppressing the adverse effects that locally large cross flow has on the cooling effect of the blade wall of the turbine blade.

[0091] 24 Stationary vane (turbine blade) 26 Moving blade (turbine blade) 34 Blade wall 34a Inner surface (of blade wall) 34b Tip side edge (of blade wall) 34c Hub side edge (of blade wall) 38 Outer shroud 40 Inner shroud 50 Space 51 Insert 52 Ridge 52c End (of rib) 52d End (of rib) 53 Recovery space 54 Flow path 54a Inner end surface 54a1 First end edge (of inner end surface) 54a2 Second end edge (of inner end surface) 54b Outer surface (of rib end) 54b1 First connecting edge (of outer surface) 54b2 Second connecting edge (of outer surface) 55 Cooling hole 55a First cooling hole 56 Internal cavity 58 Opening 58a Opening (of first cooling hole) 58b Opening (formed at a position farthest from the discharge hole) 58c Opening (formed at a position closest to the discharge hole) 59 Insert body 59a1 Outer surface (of insert body) 59b1 Outer surface (of insert body) 60 Shroud peripheral flow passage 63 Recovery flow passage 64 Discharge hole 71 Opposing surface 72 First region 73 Second region 74 Boundary region 74c Edge (of boundary region) 74d Edge (of boundary region) 80 Protrusion 80a Surface (of protrusion)

Claims

1. A turbine blade comprising: a blade wall; and an insert inserted into a space formed inside the blade wall, wherein an internal cavity communicating with the outside of the turbine blade is formed inside an insert body of the insert, a plurality of ridges are formed on the outer surface of the insert body, protruding toward the inner surface of the blade wall and having an opposing surface facing the inner surface of the blade wall, each of the plurality of ridges having a flow passage communicating with the internal cavity, and a plurality of cooling holes communicating with the flow passage, opening in the opposing surface, and aligned along the longitudinal direction of each of the plurality of ridges, a recovery space is defined between two adjacent ridges of the plurality of ridges, and a recovery flow passage communicating with the recovery space is defined between the outer surface of the insert body and the inner surface of the blade wall, and between a hub side edge of the blade wall and a hub side end of the ridge or between a tip side edge of the blade wall and a tip side end of the ridge in the longitudinal direction, The turbine impeller has a discharge hole formed in the impeller wall, the discharge hole communicating the recovery passage with the outside of the turbine impeller.

2. A turbine blade as described in claim 1, wherein, of the two ends in the longitudinal direction of each of the multiple protrusions, the outer surface of the end facing the recovery passage includes a first connecting edge connected to the outer surface of the insert body and a second connecting edge connected to the opposing surface, and at least the second connecting edge of the first connecting edge and the second connecting edge is located in a position farther toward the tip side edge of the blade wall than the hub side edge of the blade wall in the longitudinal direction, or in a position farther toward the hub side edge than the tip side edge, and the outer surface is a curved surface that is concave toward the opposite side to the recovery passage in the longitudinal direction.

3. A turbine blade as described in claim 1, wherein, of the two ends in the longitudinal direction of each of the multiple protrusions, the outer surface of the end facing the recovery flow passage includes a first connecting edge connected to the outer surface of the insert main body and a second connecting edge connected to the opposing surface, and at least the second connecting edge of the first connecting edge and the second connecting edge is located in a position away from the hub side edge of the blade wall toward the tip side edge of the blade wall in the longitudinal direction, or away from the tip side edge toward the hub side edge, and the outer surface is a flat surface.

4. A turbine blade as claimed in any one of claims 1 to 3, wherein a shroud peripheral flow passage is formed extending along the periphery of one of an outer shroud and an inner shroud provided on the tip side edge and hub side edge of the blade wall, and the recovery flow passage communicates with the shroud peripheral flow passage via the discharge hole.

5. A turbine blade according to any one of claims 1 to 3, wherein, in each of the plurality of ridges, when a cooling hole among the plurality of cooling holes formed at a position closest to the exhaust hole in the longitudinal direction is defined as a first cooling hole, a first region of the opposing surface including at least an opening of the first cooling hole protrudes toward the inner surface of the blade wall further than second regions of the opposing surface including openings of other cooling holes.

6. A turbine blade as claimed in any one of claims 1 to 3, wherein, if the opposing surfaces inside the flow passages of each of the multiple protrusions when viewed in the longitudinal direction towards the recovery flow passage are defined as internal end surfaces, the internal end surfaces include, in a direction from the internal cavity towards the opposing surface, a first edge which is the edge on the internal cavity side and a second edge which is the edge on the opposing surface side, and the internal end surfaces are configured to move away from the discharge hole in the longitudinal direction as they move from the first edge towards the second edge.

7. In each of the plurality of protrusions, a boundary region is formed connecting the first region and the second region, and the angle of the boundary region with respect to the first region is defined as θ １ The angle between the boundary region and the second region is θ ２ Then, 180° < θ １ ≦270° and 90°≦θ ２ The turbine blade of claim 5, wherein the angle is <180°.

8. A turbine blade according to any one of claims 1 to 3, wherein, if a cooling hole among the plurality of cooling holes that is formed in a position closest to the discharge hole in the longitudinal direction is defined as a first cooling hole, each of the plurality of ridges includes a first region of the opposing surface including at least an opening of the first cooling hole, and a second region of the opposing surface including openings of other cooling holes, and each of the plurality of ridges is provided with a protrusion that includes a surface that faces when the first region is viewed from the second region in the longitudinal direction, between at least one opening in the first region that is formed in a position farthest from the discharge hole in the longitudinal direction, and at least one opening in the second region that is formed in a position closest to the discharge hole in the longitudinal direction.

9. A turbine blade described in any one of claims 1 to 3, wherein, if a cooling hole among the plurality of cooling holes that is formed at a position closest to the exhaust hole in the longitudinal direction is defined as a first cooling hole, each of the plurality of protrusions includes a first region of the opposing surface including at least an opening of the first cooling hole, and a second region of the opposing surface including openings of other cooling holes, and an opening area of ​​the opening in the first region is larger than an opening area of ​​the opening in the second region.

10. A turbine blade described in any one of claims 1 to 3, wherein, if a cooling hole among the plurality of cooling holes that is formed at a position closest to the exhaust hole in the longitudinal direction is defined as a first cooling hole, each of the plurality of ridges includes a first region of the opposing surface including at least an opening of the first cooling hole, and a second region of the opposing surface including an opening of another cooling hole, and if the length of each of the plurality of ridges in a direction perpendicular to the longitudinal direction is defined as a width, then, in each of the plurality of ridges, the width of a portion including the first region is smaller than the width of a portion including the second region.

11. A turbine blade according to any one of claims 1 to 3, wherein, for each of the plurality of ridges, both end edges of the opposing surface in a direction perpendicular to the longitudinal direction are chamfered.

12. A turbine blade as claimed in any one of claims 1 to 3, wherein, if a cooling hole among the plurality of cooling holes that is formed at a position closest to the exhaust hole in the longitudinal direction is defined as a first cooling hole, each of the plurality of ridges includes a first region of the opposing surface including at least an opening of the first cooling hole, and a second region of the opposing surface including openings of other cooling holes, and in the first region of each of the plurality of ridges, both end edges of the opposing surface in a direction perpendicular to the longitudinal direction are chamfered.

13. The turbine blade according to claim 7, wherein the boundary region protrudes toward the second region from both end edges of the boundary region in a direction perpendicular to the longitudinal direction.

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