Turbine blade

Abstract

The turbine blade is provided with a blade wall and an insert inserted into a space formed inside the blade wall, and an inner cavity communicating with the outside of the turbine blade is formed inside an insert main body part of the insert. A plurality of protruding strips protruding toward the inner surface of the blade wall and having facing surfaces facing the inner surface of the blade wall are formed on the outer surface of the insert main body. A flow path communicating with the internal cavity, and a plurality of cooling holes communicating with the flow path, opening in the facing surface, and arranged in the longitudinal direction of each of the plurality of protruding strips are formed in each of the plurality of protruding strips, and a recovery space is defined between two adjacent protruding strips among the plurality of protruding strips. 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, between the hub-side edge of the blade wall and the hub-side end of the bead in the longitudinal direction, or between the tip-side edge of the blade wall and the tip-side end of the bead. A discharge hole is formed in the blade wall so as to communicate the recovery flow path with the outside of the turbine blade.

Description

Technical Field

[0001] This invention relates to a turbine blade.

[0002] This application claims priority based on 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. Background Technology

[0003] Patent Document 1 describes a turbine blade that can be cooled by impact cooling. In this turbine blade, an insert is provided in a space formed inside the blade wall. Multiple ribs are formed on the insert, protruding towards the inner surface of the blade wall. Cooling holes for ejecting cooling medium are formed at the front end of each rib. 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 has collided with the inner surface of the blade wall flows through a recovery space defined between adjacent ribs and is then discharged to the outside of the turbine blade.

[0004] If, after the cooling medium collides with the inner surface of the blade wall, it flows along the inner surface between the insert and the blade wall—a phenomenon known as crossflow—the cooling medium ejected from the cooling holes will be disturbed by the crossflow, potentially reducing the cooling efficiency of the blade wall. In contrast, in the turbine blade described in Patent Document 1, the cooling medium circulates in a recovery space after colliding with the inner surface of the blade wall, thereby reducing crossflow.

[0005] Previous technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-63997 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in the case of a structure in which multiple protrusions extend to the shroud, the cooling medium flowing in the recovery space must flow out from the inside of the blade wall through the narrow gap between the multiple protrusions and the inner surface of the blade wall, thus posing a problem of making it difficult for the cooling medium to flow out from the inside of the blade wall.

[0010] In view of the above, the object of at least one embodiment of the present invention is to provide a turbine blade that allows the cooling medium that has cooled the blade wall to flow out easily from the interior of the blade wall.

[0011] Methods for solving problems

[0012] To achieve the above objectives, the turbine blade according to the present invention comprises: a blade wall; and an insert, which is 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 portion of the insert. A plurality of protrusions are formed on the outer surface of the insert body portion, protruding toward the inner surface of the blade wall and having opposing surfaces opposite to the inner surface of the blade wall. Flow paths communicating with the internal cavity are formed in each of the plurality of protrusions; and a plurality of cooling holes communicating with the flow paths and opposite to the opposing surfaces. The blade has an opening on its surface and is arranged along the length of each of the plurality of protrusions. A recovery space is defined between two adjacent protrusions. 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 protrusion in the length direction, or between the blade tip-side edge of the blade wall and the blade tip-side end of the protrusion. A discharge hole communicating with the recovery flow path and the outside of the turbine blade is formed on the blade wall.

[0013] Invention Effects

[0014] According to the turbine blade of the present invention, the cooling medium flowing in each recovery space converges in the recovery flow path and flows out from the recovery flow path through the discharge hole, thus enabling the cooling medium that has cooled the blade wall to flow out easily from the inside of the blade wall. Attached Figure Description

[0015] Figure 1 This is a schematic structural diagram of the gas turbine involved in all embodiments of the present invention.

[0016] Figure 2 This is a diagram showing the turbine blade according to Embodiment 1 of the present invention viewed from the direction of the pressure surface toward the negative pressure surface.

[0017] Figure 3 It is along Figure 2 A cross-sectional view along line III-III.

[0018] Figure 4 It is along Figure 2 A cross-sectional view along line IV-IV.

[0019] Figure 5 This is a partially enlarged cross-sectional view of the turbine blade insert according to Embodiment 1 of the present invention.

[0020] Figure 6 This is a perspective view illustrating the structure of the plurality of protrusions of the turbine blade insert according to Embodiment 1 of the present invention.

[0021] Figure 7This is a partial cross-sectional view of the turbine blade insert and blade wall according to Embodiment 1 of the present invention.

[0022] Figure 8 This is a perspective view showing a partial structure of a modified example of the protrusion of the turbine blade insert according to Embodiment 1 of the present invention.

[0023] Figure 9 This is a front view showing a partial structure of the protrusion of the turbine blade insert according to Embodiment 2 of the present invention.

[0024] Figure 10 This is a front view showing a partial structure of the protrusion of the turbine blade insert according to Embodiment 3 of the present invention.

[0025] Figure 11 This is a cross-sectional view of the protrusion of the turbine blade insert according to Embodiment 4 of the present invention.

[0026] Figure 12 This is a cross-sectional view of another form of the protrusion of the turbine blade insert according to Embodiment 4 of the present invention.

[0027] Figure 13 This is a front view showing a partial structure of the protrusion of the turbine blade insert according to Embodiment 5 of the present invention.

[0028] Figure 14 This is a front view showing a partial structure of a modified example of the protrusion of the turbine blade insert according to Embodiment 5 of the present invention.

[0029] Figure 15 This is a front view showing a partial structure of the protrusion of the turbine blade insert according to Embodiment 5 of the present invention.

[0030] Figure 16 This is a partial cross-sectional view of the blade wall and insert of the turbine blade according to Embodiment 6 of the present invention.

[0031] Figure 17 This is a partial cross-sectional view of an insert for another form of turbine blade according to Embodiment 6 of the present invention.

[0032] Figure 18 This is a partial cross-sectional view of an insert for another form of turbine blade according to Embodiment 6 of the present invention.

[0033] Figure 19 In a modified example of the turbine blade according to Embodiment 6 of the present invention, equivalent to along Figure 2 A partial sectional view of a section of line III-III. Detailed Implementation

[0034] Hereinafter, a turbine blade according to an embodiment of the present invention will be described with reference to the accompanying drawings. The embodiments described below represent one aspect of the present invention and are not intended to limit the present invention; modifications can be made freely within the scope of the technical concept of the present invention.

[0035] (A common structure in all embodiments of the present invention)

[0036] like Figure 1 As shown, the gas turbine 1 includes: a compressor 2 for generating compressed air; a combustor 4 for generating combustion gases using compressed air and fuel; and a turbine 6 configured to be driven by the combustion gases through rotation. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0037] The compressor 2 includes multiple fixed blades 16 fixed to the side of the compressor chamber 10 and multiple rotating blades 18 mounted on the rotor 8. Air drawn in from the intake port 12 is sent into the compressor 2, and the air is compressed after passing through the multiple fixed blades 16 and the multiple rotating blades 18, thus becoming high-temperature and high-pressure compressed air.

[0038] Fuel and compressed air generated in compressor 2 are supplied to burner 4, where they are mixed and burned to generate combustion gas, which serves as the working fluid of turbine 6. Multiple burners 4 can be arranged circumferentially around the rotor within housing 20.

[0039] The turbine 6 has a combustion gas flow path 28 formed within the turbine housing 22, and includes multiple fixed blades 24 and rotating blades 26 disposed in the combustion gas flow path 28. The fixed blades 24 are fixed to the turbine housing 22 side, and the multiple fixed blades 24 arranged circumferentially along the rotor 8 constitute a fixed blade row. The rotating blades 26 are mounted on the rotor 8, and the multiple rotating blades 26 arranged circumferentially along the rotor 8 constitute a rotating blade row. The fixed blade row and the rotating blade row are arranged alternately in the axial direction of the rotor 8.

[0040] (Implementation Method 1)

[0041] <Structure of turbine blade according to Embodiment 1 of the present invention>

[0042] In Embodiment 1 of the present invention, both the fixed blade 24 and the rotating blade 26 of the turbine 6 are considered as turbine blades. Hereinafter, the turbine blade according to Embodiment 1 of the present invention will be described as the fixed blade 24, but it may also be the rotating blade 26.

[0043] like Figure 2As shown, the fixed blade 24 has a blade wall 34, which extends along the direction from the hub-side edge 34c toward the tip-side edge 34b, i.e., the blade height direction of the fixed blade 24. An outer guard 38 and an inner guard 40 are respectively provided on the tip-side edge 34b and the hub-side edge 34c. Here, "hub-side" refers to the rotating blade 26 (see reference). Figure 1 The term "blade tip side" refers to the radially rotating axis center side of the rotating track of the rotating blade 26, while "blade tip side" refers to the outer peripheral side of the radially rotating track of the rotating blade 26. Therefore, the hub-side edge 34c and the blade tip-side edge 34b correspond to the hub-side end edge and the blade tip-side end edge in the blade height direction of the fixed blade 24, respectively. 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 negative pressure surface 48 extending between the leading edge 42 and the trailing edge 44.

[0044] As described later, a space 50 is formed inside the blade wall 34 (see reference). Figure 3 ), and on the outer protective cover 38, there is formed a connecting piece 51 (described later) disposed in the space 50, which communicates with the outside of the fixed blade 24. Figure 3 ) internal cavity 56 (reference) Figure 3 Path 37. Path 37 is not limited to being formed on the outer shield 38, but can also be formed on the inner shield 40. Figure 2 In the diagram, path 37 is schematically drawn to represent a single path, but multiple paths can also be represented. The function of path 37 will be described later.

[0045] like Figure 3 As shown, a space 50 is formed inside the blade wall 34. The space 50 can be divided into multiple spaces by the intermediate wall 57, such as two spaces 50a and 50b. Alternatively, the space 50 can be divided into three or more spaces by two or more intermediate walls 57, or the space 50 can be considered a single space without intermediate walls 57. An insert 51 is inserted into the space 50. Figure 3 As illustrated, when space 50 is divided into two spaces 50a and 50b, insert 51 may have inserts 51a and 51b inserted into each space.

[0046] like Figure 4 As shown, a periphery flow path 60 is formed on the outer shield 38 along its periphery. A supply port 61 is formed at any position on the periphery flow path 60, and one end of a supply path 62 is connected to the supply port 61. As described later, the inserts 51a and 51b are respectively equipped with a flow path 60 that extends along the blade height direction of the fixed blade 24, i.e., along the direction of the blade height direction of the fixed blade 24. Figure 4Multiple protrusions 52 are formed extending vertically from the paper surface. Within the space 50 inside the blade wall 34, recovery spaces 53 are defined between adjacent protrusions 52, and recovery flow paths 63 are defined connecting each recovery space 53. A discharge hole 64 is formed on the blade wall 34, connecting the recovery flow path 63 to the outside of the blade wall 34, and the other end of the supply path 62 is connected to the discharge hole 64. That is, the recovery flow path 63 and the periphery flow path 60 of the shield are connected via the discharge hole 64, the supply path 62, and the supply port 61. In the periphery flow path 60 of the shield, a discharge port 65 communicating with the outside of the blade wall 34 is formed at any position different from the supply port 61. Alternatively, the periphery flow path 60 may not be formed on the outer shield 38, but rather on a shield without a path 37, which in the above structure is the inner shield 40 (see reference). Figure 2 ).

[0047] <Structure of the insert>

[0048] like Figure 3 As shown, the insert 51 (51a, 51b) has a blade height direction along the fixed blade 24 (and... Figure 3 A cylindrical insert body portion 59 (59a, 59b) is formed along its length axis (perpendicular to the paper surface), and an internal cavity 56 (56a, 56b) is formed inside the insert body portion 59 (59a, 59b). The internal cavities 56 (56a, 56b) are connected to path 37 (see reference). Figure 2 The inserts are connected. Multiple protrusions 52 protruding toward the inner surface 34a of the blade wall 34 are formed on the outer surfaces 59a1 and 59b1 of the main bodies 59a and 59b, respectively. In each insert, the multiple protrusions 52 extend along the blade height direction of the fixed blade 24 and are arranged at intervals in the circumferential direction centered on the length axis. In each insert, a retraction space 53 is defined between adjacent protrusions 52 in the circumferential direction centered on the length axis.

[0049] Next, the structure of the protrusion 52 will be explained. Figure 5 The image shows a portion of a plurality of protrusions 52 disposed in the insert 51a. (See reference) Figure 5 The structure of the protrusion 52 described below also applies to all or part of the protrusions 52 provided in other inserts 51b.

[0050] A cavity, i.e., a flow path 54, is formed inside the protrusion 52, communicating with the internal cavity 56a. Furthermore, a plurality of cooling holes 55 are formed on the protrusion 52, communicating with the flow path 54 and opening opposite to the inner surface 34a of the blade wall 34. Figure 5 In the middle, one of the multiple cooling holes 55 is depicted in each of the protrusions 52.

[0051] To uniformly cool the entire fixed blade 24, the ribs 52 can be arranged at equal intervals, or the spacing between adjacent ribs 52, 52 on areas requiring particular cooling can be smaller than the spacing between adjacent ribs 52, 52 on other areas. For example, the spacing between ribs 52, 52 arranged on the ventral side of the fixed blade 24 can be smaller than the spacing between ribs 52, 52 arranged on the dorsal side of the fixed blade 24. Furthermore, the ribs 52 arranged on the ventral and dorsal sides of the fixed blade 24 can be arranged such that the spacing between adjacent ribs 52, 52 gradually increases from the leading edge to the trailing edge of the fixed blade 24.

[0052] Figure 6 The diagram shows any two adjacent slats 52a and 52b. The structure described below also applies to other adjacent slats besides slats 52a and 52b. Slats 52a and 52b each have an inner surface 34a facing the blade wall 34 (see reference). Figure 3 The fixed blade 24 protrudes and extends along its blade height direction in a track-like shape, having an end 52c on the tip side and an end 52d on the hub side, and having opposing surfaces 71 (71a, 71b) opposite to the inner surface 34a. In Embodiment 1, the opposing surfaces 71 are divided into a first region 72 (72a, 72b) and a second region 73 (73a, 73b). A boundary region 74 (74a, 74b) connecting the first region 72 and the second region 73 is provided.

[0053] On the opposing surface 71, the openings 58 of a plurality of cooling holes 55 are arranged in a row along the length direction of the rib 52 (as described above, the rib 52 extends along the blade height direction of the fixed blade 24). The number of cooling holes 55 formed in each rib 52 (synonymous with the openings 58a formed on each opposing surface 71) is arbitrary. Furthermore, the spacing between adjacent cooling holes 55, 55 can be equal or different. In the latter case, for example, the spacing between adjacent cooling holes 55, 55 can gradually increase from the hub side toward the blade tip side, and conversely, the spacing between adjacent cooling holes 55, 55 can gradually increase from the blade tip side toward the hub side.

[0054] Figure 6 The text describes a structure with two openings 58 in region 72 and five openings 58 in region 73, but this structure is merely illustrative. At least one cooling hole 55 opening 58 is formed in region 72. The "at least one cooling hole 55 opening 58" formed in region 72 is located closest to the recovery flow path 63 along the length of the protrusion 52, i.e., closest to the discharge hole 64 (see reference). Figure 4The opening 58a of the first cooling hole 55a is formed at the position of ).

[0055] In region 72, it is sufficient to form at least one opening 58a for the first cooling hole 55a; the number of openings 58 formed in region 72 is arbitrary. For example, in region 72, two openings can be formed: one opening 58a and one adjacent opening 58 (equivalent to...). Figure 6 The structure can also have three openings: opening 58a and two openings 58 located next to it. The openings other than the one formed in the first region 72 are formed in the second region 73. That is, no opening 58 is formed in the boundary region 74.

[0056] The number of openings 58 formed in the first region 72 and the second region 73 depends on the spacing between adjacent openings 58 and the length of the first region 72 and the second region 73 in the longitudinal direction of the protrusion 52. However, the number of openings formed in the first region 72 is less than the number of openings formed in the second region 73. In the longitudinal direction of the protrusion 52, the length of the first region 72 is less than the length of the second region 73. The length of the first region 72 is preferably less than half the length of the protrusion 52, more preferably less than one-third of the length of the protrusion 52, and most preferably less than one-quarter of the length of the protrusion 52.

[0057] like Figure 7 As shown, the first region 72 is configured to protrude further toward the inner surface 34a of the blade wall 34 than the second region 73. That is, the distance L1 from the opening 58 formed in the first region 72 to the inner surface 34a is less than the distance L2 from the opening 58 formed in the second region 73 to the inner surface 34a. If the angle between the boundary region 74 and the first region 72 is set as θ1, and the angle between the boundary region 74 and the second region 73 is set as θ2, then the range of angle θ1 is 180° < θ1 ≤ 270°, and the range of angle θ2 is 90° ≤ θ2 < 180°.

[0058] In addition, Figure 7 In this structure, since the discharge hole 64 is formed near the tip-side edge 34b of the blade wall 34, the recovery flow path 63 is defined between the outer surface 59a1 of the insert body 59a and the inner surface 34a of the blade wall 34, and between the tip-side edge 34b of the blade wall 34 and the tip-side end 52c of the protrusion 52 along the length of the protrusion 52. The discharge hole 64 is formed at the hub-side edge 34c of the blade wall 34 (see reference). Figure 2 In the vicinity of the insertion body 59a, the recovery flow path 63 is defined between the outer surface 59a1 of the insertion body 59a and the inner surface 34a of the blade wall 34, and in the longitudinal direction between the hub-side edge 34c of the blade wall 34 and the hub-side end 52d of the protrusion 52 (see reference). Figure 6 )between.

[0059] The outer surface 54b of the end 52c facing the recovery flow path 63 includes a first connecting edge 54b1 that connects to the outer surface 59a1 of the insert body 59a and a second connecting edge 54b2 that connects to the opposing surface 71. The first connecting edge 54b1 and the second connecting edge 54b2 are located further toward the hub-side edge 34c than the tip-side edge 34b of the blade wall 34 in the length direction of the protrusion 52 (see reference). Figure 2 The outer surface 54b is a flat surface. According to this structure, a recovery flow path 63 is formed between the tip edge 34b and the end point 52c in the length direction of the rib 52. Furthermore, the first connecting edge 54b1 can be located at the same position as the tip edge 34b in the length direction. That is, of the first connecting edge 54b1 and the second connecting edge 54b2, at least the second connecting edge 54b2 can be located further away from the hub edge 34c than the tip edge 34b of the blade wall 34 in the length direction of the rib 52.

[0060] <Cooling action of blade wall in turbine blade according to Embodiment 1 of the present invention>

[0061] The cooling operation of the blade wall in the turbine blade according to Embodiment 1 of the present invention will be described. For example... Figure 2 As shown, a cooling medium (e.g., cooling air) is supplied from the outside of the fixed blade 24 to the inside of the blade wall 34 via path 37. Figure 3 As shown, the cooling medium flows into the internal cavities 56a and 56b inside the blade wall 34, respectively. Figure 5 As shown, for example, the cooling medium flowing into the internal cavity 56a flows into the flow path 54, then into the cooling hole 55, and is ejected from the opening 58 toward the inner surface 34a of the blade wall 34. The cooling medium ejected from the cooling hole 55 collides with the inner surface 34a of the blade wall 34, thereby cooling the blade wall 34. After colliding with the inner surface 34a of the blade wall 34, the cooling medium is guided into the recovery space 53 defined between adjacent protrusions 52, 52.

[0062] like Figure 4As shown, the cooling medium introduced into the recovery space 53 flows toward the recovery flow path 63 within the recovery space 53 and flows from the recovery space 53 into the recovery flow path 63. The cooling medium flowing in each recovery space 53 converges within the recovery flow path 63 and flows out of the recovery flow path 63 through the discharge hole 64. After flowing in the supply path 62, the cooling medium flowing out of the recovery flow path 63 flows into the shroud periphery flow path 60 through the supply port 61. After flowing in the shroud periphery flow path 60, the cooling medium flowing into the shroud periphery flow path 60 flows out of the shroud periphery flow path 60 to the outside of the fixed blade 24 through the discharge port 65.

[0063] If, after a collision between the cooling medium and the inner surface 34a of the blade wall 34, the cooling medium flows in the direction along the inner surface 34a near other openings 58 (i.e., crossflow), the cooling medium ejected from the other openings 58 is disturbed by the crossflow, which may reduce cooling efficiency. In contrast, in the fixed blade 24 with the above structure, the cooling medium is guided into the recovery space 53 after colliding with the inner surface 34a of the blade wall 34, thus reducing crossflow and suppressing the possibility of reduced cooling efficiency of the blade wall 34.

[0064] However, in the above structure, when there is crossflow that is not introduced into the recovery space 53, the cooling medium in the recovery flow path 63 flows out from the discharge hole 64 to the outside of the blade wall 34, and the crossflow locally increases in the region near the discharge hole 64 along the length of the spur 52. As a result, in the region near the discharge hole 64 along the length of the spur 52, the cooling medium ejected from the opening 58 of the cooling hole 55 is disturbed by the locally large crossflow (for example, the flow of the ejected cooling medium is bent), thereby reducing the cooling efficiency of the blade wall 34.

[0065] In contrast, in implementation 1, such as Figure 7 As shown, in each protrusion 52, the distance L1 from the opening 58 formed in the first region 72 to the inner surface 34a is smaller than the distance L2 from the opening 58 formed in the second region 73 to the inner surface 34a. Therefore, in the region of the protrusion 52 near the discharge hole 64, i.e., the first region 72, because the distance L1 from the opening 58 to the inner surface 34a is small, the cooling medium ejected from the opening 58 in the first region 72 can collide with the inner surface 34a of the blade wall 34 before its flow bends due to crossflow. That is, the effect of the cooling medium ejected from the opening 58 in the first region 72 bending due to crossflow can be suppressed, thus suppressing the adverse effects of large local crossflow on the cooling effect of the blade wall 34.

[0066] The crossflow flowing between region 73 and the inner surface 34a of the blade wall 34, moving towards region 72, changes direction after colliding with boundary region 74 and flows into the recovery space 53 on both sides of the protrusion 52 (see reference). Figures 3-6 As a result, the crossflow flowing into the first region 72 and the inner surface 34a of the blade wall 34 is reduced, thus weakening the effect of crossflow on the flow of cooling medium ejected from the opening 58 in the first region 72. Furthermore, the cooling medium flowing in each recovery space 53 converges within the recovery flow path 63 and flows out through the discharge hole 64, thus allowing the cooling medium that has cooled the blade wall 34 to flow out from the interior of the blade wall 34.

[0067] <Example of a modified turbine blade according to Embodiment 1 of the present invention>

[0068] In embodiment 1, although the boundary region 74 is a flat surface, it can also be a curved surface that curves in a way that is concave towards the first region 72. Furthermore, as... Figure 8 As shown, the boundary region 74 may have a structure in which two end edges 74c and 74d of the boundary region 74 protrude toward the second region 73 in a direction orthogonal to the length direction (the width direction of the protrusion 52). In this structure, the boundary region 74 has a protruding edge 74e between the end edges 74c and 74d in the width direction of the protrusion 52, and has a first surface 74f and a second surface 74g on both sides of the protruding edge 74e in the width direction of the protrusion 52. With this structure of the boundary region 74, the crossflow flowing along the second region 73 toward the boundary region 74 (in the direction of arrow A) becomes a flow divided toward both sides of the protruding edge 74e by colliding with it (arrows B and C). One side of the divided crossflow (arrow B) flows along the first surface 74f, and the other side (arrow C) flows along the second surface 74g, thereby flowing into the recovery spaces 53, 53 (arrows D and E) on both sides of the protrusion 52. As a result, the crossflow flowing into the first region 72 between the inner surface 34a of the blade wall 34 is reduced, thus weakening the effect of crossflow on the flow of cooling medium ejected from the opening 58 in the first region 72.

[0069] (Implementation Method 2)

[0070] Next, the turbine blade according to Embodiment 2 of the present invention will be described. Embodiment 2 will be described as a structure independent of Embodiment 1, but it may also have a structure described below based on the structure of Embodiment 1 and its modifications. In addition, in Embodiment 2, the same reference numerals are used for components that are the same as those in Embodiment 1, and their detailed descriptions are omitted.

[0071] <Structure of turbine blade according to Embodiment 2 of the present invention>

[0072] like Figure 9 As shown, in the first region 72 on the opposite surface 71 of the protrusion 52, similar to the exemplary structure of Embodiment 1, an opening 58a of the first cooling hole 55a and an opening 58 located next to the opening 58a are formed. The number of openings 58 in the first region 71 is not limited to two, as is the case with Embodiment 1. Embodiment 2 may involve the first region 72 not being further toward the inner surface 34a of the blade wall 34 than the second region 73 (see reference). Figures 3-5 Instead of being a protrusion, the two form a structure on the same plane (as described above, it can have the structure of Embodiment 1 and its variations). In this case, the boundary region 74 is not a surface as in Embodiment 1, but becomes a boundary line extending along the width direction of the protrusion 52.

[0073] In embodiment 2, the opening area of ​​each opening 58 formed in the first region 72 is larger than the opening area of ​​each opening 58 formed in the second region 73. Figure 9 The diagram includes a circular opening 58, but the opening 58 is not limited to a circle. It can be an ellipse that is longer in the length direction, width direction, or a direction in between, or it can be any shape such as a polygon or an irregular shape. Furthermore, all openings can have different shapes, and at least a few openings can have different shapes.

[0074] <Cooling action of blade wall in turbine blade according to Embodiment 2 of the present invention>

[0075] The cooling operation of the blade wall in the turbine blade according to Embodiment 2 of the present invention is basically the same as that in Embodiment 1. As a difference from Embodiment 1, since the opening area of ​​the opening 58 formed in the first region 72 is larger than the opening area of ​​the opening 58 formed in the second region 73, the flow rate of the cooling medium ejected from the opening 58 in the first region 72 is greater than the flow rate of the cooling medium ejected from the opening 58 in the second region 73. Therefore, even if the crossflow flowing between the first region 72 and the inner surface 34a locally increases and the cooling efficiency of the blade wall 34 may decrease, the possibility of a decrease in cooling efficiency can be compensated by increasing the flow rate of the cooling medium ejected toward the inner surface 34a opposite to the first region 72. Thus, the adverse effects of locally large crossflow on the cooling effect of the blade wall 34 can be suppressed.

[0076] In Embodiment 1, to address the localized increase in crossflow between the first region 72 and the inner surface 34a of the blade wall 34, the distance between the first region 72 and the inner surface 34a is reduced so that the cooling medium ejected from the opening 58 in the first region 72 can collide with the inner surface 34a before being bent by the crossflow. In Embodiment 2, the flow rate of the ejected cooling medium is increased by increasing the opening area of ​​the opening 58 formed in the first region 72 to compensate for the potential decrease in cooling efficiency of the blade wall 34 caused by the large localized crossflow. On the other hand, in the structure of Embodiment 2, due to the difference in the opening areas of the opening 58 in the first region 72 and the opening 58 in the second region 73, the flow of the cooling medium ejected from the opening 58 in the first region 72 has a larger cross-sectional area of ​​flow cut off in the direction orthogonal to the flow direction compared to the flow of the cooling medium ejected from the opening 58 in the second region 73. Therefore, the flow of the cooling medium ejected from the opening 58 in the first region 72 may have the effect of being less prone to bending by the crossflow. From the viewpoint that the cooling medium ejected from the opening 58 in the first region 72 does not easily bend during the period until it collides with the inner surface 34a, the effect described above in Embodiment 1 and the effect described above in Embodiment 2 are both general effects. This effect can be appropriately obtained by adjusting the parameters described below.

[0077] The distance L1 from the opening 58 formed in the first region 72 to the inner surface 34a of the blade wall 34 (refer to) Figure 7 The ratio L1 / D1, which is the diameter D1 calculated from the opening area of ​​the opening 58 when the opening 58 formed in the first region 72 is considered circular, is adjusted as the aforementioned index. Specifically, the ratio L1 / D1 is only required to be less than the ratio L2 / D2 for the opening 58 formed in the second region 73 (D2 is the diameter calculated from the opening area of ​​the opening 58 when the opening 58 formed in the second region 73 is considered circular). If this ratio is to be controlled, a structure that can reliably obtain the aforementioned effect can be designed if the opening area of ​​the opening 58 and the distance from the opening 58 to the inner surface 34a are different in the first region 72 and the second region 73.

[0078] (Implementation Method 3)

[0079] Next, the turbine blade according to Embodiment 3 of the present invention will be described. Embodiment 3 is described as a structure independent of Embodiments 1 and 2, but it is also possible to have a structure of Embodiment 3 described below based on the structures of Embodiments 1 and 2 and their modifications. In addition, in Embodiment 3, the same reference numerals are used for components that are the same as those in Embodiments 1 and 2, and their detailed descriptions are omitted.

[0080] <Structure of turbine blade according to Embodiment 3 of the present invention>

[0081] like Figure 10 As shown, in the protrusions 52, the width W1 of the protrusions 52 in the first region 72 is smaller than the width W2 of the protrusions 52 in the second region 73. As a result, the width W3 of the recycling space 53 formed between the first regions 72a and 72b is greater than the width W4 of the recycling space 53 formed between the second regions 73a and 73b.

[0082] <Cooling action of blade wall in turbine blade according to Embodiment 3 of the present invention>

[0083] The cooling action of the blade wall in the turbine blade according to Embodiment 3 of the present invention is basically the same as that in Embodiment 1. As a difference from Embodiment 1, the width W3 of the recovery space 53 formed between the first regions 72a and 72b is greater than the width W4 of the recovery space 53 formed between the second regions 73a and 73b. Therefore, the crossflow between the second region 73 and the inner surface 34a of the blade wall 34 (see reference) Figures 3-5 Compared to the flow between the first region 72 and the inner surface 34a of the blade wall 34, the crossflow is more likely to flow into the recovery space 53 when flowing between the first region 72 and the inner surface 34a of the blade wall 34. Due to this difference, the crossflow flowing between the first region 72 and the inner surface 34a of the blade wall 34 can be reduced, thus suppressing the adverse effects of large local crossflow on the cooling effect of the blade wall 34.

[0084] (Implementation Method 4)

[0085] Next, the turbine blade according to Embodiment 4 of the present invention will be described. Embodiment 4 is described as a structure independent of the structures of Embodiments 1 to 3, but it is also possible to have a structure of Embodiment 4 described below based on the structures of Embodiments 1 to 3 and their modifications. In addition, in Embodiment 4, the same reference numerals are used for components that are the same as those in Embodiments 1 to 3, and their detailed descriptions are omitted.

[0086] <Structure of turbine blade according to embodiment 4 of the present invention>

[0087] like Figure 11 As shown, in the first region 72 of the protrusion 52, the two end edges 71c and 71d of the opposing surface 71 in the width direction of the protrusion 52 are chamfered. The chamfered area of ​​the two end edges 71c and 71d is at least the first region 72, but the boundary region 74 (see reference) Figure 6 and 7 ) and Zone 2, 73 (reference) Figure 6 and 7It can also be chamfered. That is, both ends of the protrusion 52 can be completely chamfered. Regarding the shape of the chamfer, as follows: Figure 11 As shown, it is not limited to the shape where the cross-section is beveled into a curved shape, such as Figure 12 As shown, it can also be a shape where the cross-section is beveled into a straight line shape.

[0088] <Cooling action of blade wall in turbine blade according to Embodiment 4 of the present invention>

[0089] The cooling action of the blade wall in the turbine blade according to Embodiment 4 of the present invention is basically the same as that in Embodiment 1. As a difference from Embodiment 1, since the two end edges 71c and 71d of the first region 72 of the opposing surface 71 in the width direction of the rib 52 are chamfered, the crossflow flowing between the first region 72 and the inner surface 34a of the blade wall 34 is more likely to flow into the recovery space 53 compared to the case where the two end edges 71c and 71d are not chamfered. Due to this difference, the crossflow flowing between the first region 72 and the inner surface 34a of the blade wall 34 can be reduced, thus suppressing the adverse effects of large local crossflow on the cooling effect of the blade wall 34.

[0090] (Implementation Method 5)

[0091] Next, the turbine blade according to Embodiment 5 of the present invention will be described. Embodiment 5 is described as a structure independent of the structures of Embodiments 1 to 4, but it is also possible to have a structure of Embodiment 5 described below based on the structures of Embodiments 1 to 4 and their modifications. In addition, in Embodiment 5, the same reference numerals are used for components that are the same as those in Embodiments 1 to 4, and their detailed descriptions are omitted.

[0092] <Structure of turbine blade according to Embodiment 5 of the present invention>

[0093] like Figure 13 As shown, in the protrusion 52, the opening 58 in the first region 72 is furthest from the discharge hole 64 in the length direction of the protrusion 52 (reference). Figure 4The opening formed at the position of the first region 72 is designated as opening 58b, and the opening formed at the position closest to the discharge hole 64 in the longitudinal direction of the protrusion 52 among the openings 58 in the second region 73 is designated as opening 58c. Additionally, if there is only one opening 58a formed in the first region 72, then opening 58a becomes opening 58b. A rectangular, plate-shaped protrusion 80 is provided on the opposing surface 71 of the protrusion 52 between opening 58b and opening 58c. The plate-shaped protrusion 80 has an opposing surface 80a when the first region 72 is viewed from the second region 73 in the longitudinal direction of the protrusion 52. When the protrusion 80 is rectangular and plate-shaped, surface 80a is preferably perpendicular to both the opposing surface 71 and the longitudinal direction of the protrusion 52, but is not limited to strict perpendicularity; approximately perpendicularity is sufficient.

[0094] <Cooling operation of the blade wall in the turbine blade according to Embodiment 5 of the present invention>

[0095] The cooling action of the blade wall in the turbine blade according to Embodiment 5 of the present invention is basically the same as that in Embodiment 1. As a different action from Embodiment 1, the crossflow flowing between the second region 73 and the inner surface 34a of the blade wall 34, in the direction of flow toward the first region 72 (arrow F1), collides perpendicularly with the surface 80a. If the crossflow collides perpendicularly with the surface 80a, after colliding with the surface 80a, the crossflow changes its flow direction to the direction along the surface 80a (arrows G1 and H1) and flows into the recovery space 53 on both sides of the protrusion 52. As a result, the crossflow flowing into the area between the first region 72 and the inner surface 34a of the blade wall 34 is reduced, thus weakening the effect of the crossflow caused by the flow of the cooling medium ejected from the opening 58 in the first region 72. Therefore, the adverse effects of large local crossflows on the cooling effect of the blade wall 34 can be suppressed.

[0096] <Example of a modified turbine blade according to Embodiment 5 of the present invention>

[0097] The protrusion 80 is not limited to being rectangular or plate-shaped. The protrusion 80 can have any shape as long as it has a shape that is opposite to the surface 80a when viewed from the second region 73 along the length of the protrusion 52. Furthermore, "opposite" is not limited to being perpendicular to the length of the protrusion 52; it is sufficient that the surface 80a is visible when the protrusion 80 is viewed in the aforementioned direction. For example, as... Figure 14As shown, the protrusion 80 may have a structure in which two end edges 80b and 80c of the protrusion 80 protrude toward the second region 73 in the width direction of the protrusion 52. In this structure, the surface 80a has a protruding edge 80d between the end edges 80b and 80c in the width direction of the protrusion 52, and a first surface 80a1 and a second surface 80a2 are located on both sides of the protruding edge 80d in the width direction of the protrusion 52. When the protrusion 80 has this structure, the crossflow flowing along the second region 73 toward the protrusion 80 (in the direction of arrow F2) becomes a flow divided toward both sides of the protruding edge 80d by colliding with it (arrows G2 and H2). One of the divided crossflows (arrow G2) flows along the first surface 80a1, and the other (arrow H2) flows along the second surface 80a2, thereby flowing into the recovery spaces 53, 53 on both sides of the protrusion 52. As a result, the crossflow flowing into the first region 72 between the inner surface 34a of the blade wall 34 is reduced, thus weakening the effect of crossflow on the flow of cooling medium ejected from the opening 58 in the first region 72.

[0098] Moreover, for example, such as Figure 15 As shown, the protrusion 80 can be composed of two plates 81, 81 in the shape of a right triangle. Each plate 81 includes a surface 81a as one side of the right triangle and a back surface 81b as the other side of the right triangle. An inclined plane 82 is defined between the hypotenuses 81a1 and 81b1 of each surface 81a and back surface 81b. The two plates 81, 81 are configured such that their respective inclined planes 82 face the second region 73 in the longitudinal direction of the protrusion 52, and when the protrusion 80 is viewed toward the opposing surface 71, the distance between the two inclined planes 82, 82 in the width direction of the protrusion 52 decreases in the direction from the second region 73 toward the first region 72. In this structure, the surface 81a of each plate 81 is equivalent to surface 80a. With this structure, the crossflow flowing along the second region 73 toward the protrusion 80 (in the direction of arrow F3) becomes a flow (vortex) across each plate 81 and flows into the recovery spaces 53, 53 on both sides of the protrusion 52. As a result, the crossflow flowing into the first region 72 between the inner surface 34a of the blade wall 34 is reduced, thus weakening the effect of crossflow on the flow of cooling medium ejected from the opening 58 in the first region 72.

[0099] When the protrusion 80 is provided based on the structure of Embodiment 1 and its variations, the protrusion 80 can be provided in the first region 72 or the second region 73. Regarding the boundary region 74, if the angle θ1 (refer to...) Figure 7 The value is smaller and the angle θ2 (reference) Figure 7If the value is large, a protrusion 80 can be provided in the boundary region 74. Furthermore, it is not necessary to base the structure on Embodiment 1 and its variations on the assumption that the angle θ1 (refer to...) can be used instead. Figure 7 ) and angle θ2 (reference) Figure 7 All angles are set to 180°, and a protrusion 80 is set in the boundary region 74.

[0100] (Implementation Method 6)

[0101] Next, the turbine blade according to Embodiment 6 of the present invention will be described. Embodiment 6 is described as a structure independent of the structures of Embodiments 1 to 5, but it is also possible to have the structure of Embodiment 6 described below based on the structures of Embodiments 1 to 5 and their modifications. In addition, in Embodiment 6, the same reference numerals are used for components that are the same as those in Embodiments 1 to 5, and their detailed descriptions are omitted.

[0102] <Structure of turbine blade according to Embodiment 6 of the present invention>

[0103] like Figure 16 As shown, inside the flow path 54 within the protrusion 52, the surface facing the recovery flow path 63 in the longitudinal direction of the protrusion 52 is designated as an inner end face 54a. The inner end face 54a includes a first end edge 54a1, which is the end edge on the side of the inner cavity 56, and a second end edge 54a2, which is the end edge on the side of the opposite surface 71, in the direction from the inner cavity 56 toward the opposite surface 71. The inner end face 54a is configured to move away from the discharge hole 64 in the longitudinal direction of the protrusion 52 as it moves from the first end edge 54a1 toward the second end edge 54a2.

[0104] The internal end face 54a can be of any shape as long as it possesses this characteristic. For example, as... Figure 16 As shown, the inner end face 54a can be a curved surface that protrudes in the longitudinal direction of the protrusion 52 toward the side opposite to the recovery flow path 63. When the inner end face 54a is such a curved surface, the outer surface 54b of the end 52c of the protrusion 52 can also be a curved surface that, like the inner end face 54a, protrudes in the longitudinal direction of the protrusion 52 toward the direction away from the discharge hole 64. When the outer surface 54b is such a curved surface, in embodiment 6, at least the second connecting edge 54b2 is located further toward the hub side edge 34c in the longitudinal direction of the protrusion 52 than the tip side edge 34b of the blade wall 34 (see reference). Figure 2 The position of ) forms a recovery flow path 63 in the longitudinal direction between the tip edge 34b and the end 52c. Furthermore, as Figure 17 As shown, the inner end face 54a can be a flat surface from the first end edge 54a1 to the second end edge 54a2, such as... Figure 18 As shown, it can also be relative to Figure 17 The structure changes the cross-sections of the first end edge 54a1 and the second end edge 54a2 into a curved shape.

[0105] <Cooling operation of the blade wall in a turbine blade according to Embodiment 6 of the present invention>

[0106] The cooling action of the blade wall in the turbine blade according to Embodiment 6 of the present invention is basically the same as that in Embodiment 1. In Embodiment 1, as... Figure 7 As shown, since the inner end face 54a is perpendicular to the length direction of the protrusion 52, the boundary between the inner surface 56a of the inner cavity 56 and the inner end face 54a, i.e., the first end edge 54a1, has a right-angled cross-sectional shape. Therefore, when the cooling medium flows from the inner cavity 56 into the flow path 54, separation easily occurs in the first end edge 54a1. In contrast, in Embodiment 6... Figure 16 and Figure 18 In the structure, the first end edge 54a1 has a curved, smooth shape, so when the cooling medium flows from the internal cavity 56 into the flow path 54, separation is less likely to occur in the first end edge 54a1. Furthermore, in Figure 17 In the structure, the angle in the cross-sectional shape of the first end edge 54a1 is greater than 90°, so when the cooling medium flows from the internal cavity 56 into the flow path 54, it is not easy for separation to occur in the first end edge 54a1.

[0107] Thus, since the possibility of flow separation of the cooling medium when it flows from the internal cavity 56 into the flow path 54 can be reduced, the possibility of a decrease in the flow rate of the cooling medium ejected from the opening 58 of the cooling hole 55 can be reduced, and the adverse effects on the cooling effect on the blade wall 34 can be suppressed.

[0108] <Examples of turbine blade modifications according to Embodiments 1 to 6 of the present invention>

[0109] Furthermore, the structure of forming a recovery flow path 63 within the blade wall 34 is not limited to the form of the protrusions 52 as described in Embodiments 1 to 6. Even when the structure of the protrusions 52 is not the form described in Embodiments 1 to 6, but rather a structure with any protrusion structure, the cooling medium that has cooled the blade wall 34 can still easily flow out from the interior of the blade wall 34 by providing the recovery flow path 63. Moreover, the structures of Embodiments 2 to 5 are not necessarily based on the premise that the first region 72 on the opposing surface 71 of each protrusion 52 protrudes further toward the inner surface 34a of the blade wall 34 than the second region 73. Even if the first region 72 does not protrude further 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 exist on the same plane, this is also acceptable.

[0110] exist Figure 4 In the diagram, the supply path 62 connecting the discharge port 64 and the supply port 61 is drawn with a certain length, but this length is arbitrary and can be longer than... Figure 4 The structure of the supply path 62 shown is short in length, for example, as... Figure 19 As shown, it can also be a structure where there is no supply path 62 and the discharge hole 64 is directly connected to the supply port 61.

[0111] The contents described in the above embodiments can be understood as follows, for example.

[0112] [1] A turbine blade (fixed blade 24 / rotating blade 26) according to one embodiment includes:

[0113] Blade wall 34; and

[0114] Insert 51 is inserted into the space 50 formed inside the blade wall 34, wherein,

[0115] An internal cavity 56 communicating with the outside of the turbine blades 24 / 26 is formed inside the insert body portion 59 of the insert 51.

[0116] On the outer surfaces 59a1 and 59b1 of the insert body 59, a plurality of protrusions 52 are formed that protrude toward the inner surface 34a of the blade wall 34 and have opposing surfaces 71 that face the inner surface 34a of the blade wall 34.

[0117] The plurality of protrusions 52 are respectively formed with:

[0118] Flow path 54 is connected to the internal cavity 56; and

[0119] Multiple cooling holes 55 communicate with the flow path 54 and open on the opposing surface 71, and are arranged along the length direction of each of the multiple protrusions 52.

[0120] A retraction space 53 is defined between two adjacent protrusions 55, 55 among the plurality of protrusions 52.

[0121] A recovery flow path 63 communicating with the recovery space 53 is defined between the outer surfaces 59a1 and 59b1 of the insert body 59 and the inner surface 34a of the blade wall 34, and in the longitudinal direction, between the hub-side edge 34c of the blade wall 34 and the hub-side end 52d of the protrusion 52, or between the blade tip-side edge 34b of the blade wall 34 and the blade tip-side end 52c of the protrusion 52.

[0122] A discharge hole 64 is formed on the blade wall 34, which connects the recovery flow path 63 with the outside of the turbine blades 24 / 26.

[0123] According to the turbine blade of the present invention, the cooling medium flowing in each recovery space converges in the recovery flow path and flows out from the recovery flow path through the discharge hole, thus enabling the cooling medium that has cooled the blade wall to flow out easily from the inside of the blade wall.

[0124] [2] In another embodiment, the turbine blade is the turbine blade of [1], wherein,

[0125] Of the plurality of protrusions 52, the outer surface 54b of the two ends 52c, 52d facing the recycling flow path 63 in the length direction of each of the plurality of protrusions 52 includes:

[0126] The first connecting edge 54b1 is connected to the outer surfaces 59a1 and 59b1 of the insert body 59; and

[0127] The second connecting edge 54b2 is connected to the opposing surface 71.

[0128] Of the first connecting edge 54b1 and the second connecting edge 54b2, at least the second connecting edge 54b2 is located in the length direction further away from the blade tip edge 34b of the blade wall 34 than the hub side edge 34c of the blade wall 34, or further away from the hub side edge 34c than the blade tip edge 34b.

[0129] The outer surface 54b is a surface that is curved in the longitudinal direction toward the side opposite to the recycling flow path 63.

[0130] According to this structure, a recycling flow path is formed along the length of the spur between the tip edge and the end point, or between the hub edge and the end point.

[0131] [3] In another embodiment, the turbine blade is the turbine blade of [1], wherein,

[0132] In each of the plurality of protrusions 52, at its two ends 52c, 52d along its length direction, the outer surface 54b of the ends 52c, 52d facing the recycling flow path 63 includes:

[0133] The first connecting edge 54b1 is connected to the outer surfaces 59a1 and 59b1 of the insert body 59; and

[0134] The second connecting edge 54b2 is connected to the opposing surface 71.

[0135] Of the first connecting edge 54b1 and the second connecting edge 54b2, at least the second connecting edge 54b2 is located in the length direction further away from the blade tip edge 34b of the blade wall 34 than the hub side edge 34c of the blade wall 34, or further away from the hub side edge 34c than the blade tip edge 34b.

[0136] The outer surface 54b is a flat surface.

[0137] According to this structure, a recycling flow path is formed along the length of the spur between the tip edge and the end point, or between the hub edge and the end point.

[0138] [4] In another embodiment, the turbine blade is any one of [1] to [3], wherein,

[0139] One of the outer shield 38 and the inner shield 40 respectively provided on the blade tip side edge 34b and the hub side edge 34c of the blade wall 34 forms a shield peripheral flow path 60 extending along its periphery.

[0140] The recycling flow path 63 is connected to the periphery flow path 60 of the protective cover via the discharge hole 64.

[0141] According to this structure, the cooling medium flowing out from the recovery flow path through the discharge hole flows through the flow path around the shield and then flows out from the flow path around the shield to the outside of the fixed blade through the discharge port formed in the flow path around the shield. Therefore, the cooling medium that has cooled the blade wall can easily flow out from the inside of the blade wall.

[0142] [5] In another embodiment, the turbine blade is any one of [1] to [4], wherein,

[0143] In each of the plurality of protrusions 52, if the cooling hole 55 formed at the position closest to the discharge hole 64 in the longitudinal direction among the plurality of cooling holes 55 is designated as the first cooling hole 55a, then the first region 72 of the opposing surface 71 including at least the opening 58a of the first cooling hole 55a protrudes further toward the inner surface 34a of the blade wall 34 than the second region 73 of the opposing surface 71 including the openings 58 of the other cooling holes 55.

[0144] According to the turbine blade of the present invention, in the length direction of each of the plurality of protrusions, the crossflow sometimes locally increases in the region near the discharge hole. However, the first region of the opposing surface of the opening of the first cooling hole, which is formed at the position closest to the discharge hole among the plurality of cooling holes formed in the plurality of protrusions, protrudes more toward the inner surface of the blade wall than the second region of the opposing surface of the opening 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 bends through the crossflow. Therefore, the adverse effect of the locally increased crossflow on the cooling effect of the turbine blade wall can be suppressed.

[0145] [6] In another embodiment, the turbine blade is any one of [1] to [5], wherein,

[0146] Inside the flow path 54 of each of the plurality of protrusions 52, if the face facing the opposite direction when viewed along the length direction toward the recycling flow path 63 is defined as the inner end face 54a.

[0147] The internal end face 54a, in the direction from the internal cavity 56 toward the opposing surface 71, includes an end edge 54a1 on the side of the internal cavity 56, i.e., a first end edge 54a1, and an end edge 54a2 on the side of the opposing surface 71, i.e., a second end edge 54a2.

[0148] The inner end face 54a is configured to move away from the discharge hole 64 in the length direction as it moves from the first end edge 54a1 toward the second end edge 54a2.

[0149] When the internal end face is perpendicular to the length direction of the rib, when the cooling medium flowing in the internal cavity flows into the flow path inside the rib, the flow of the cooling medium is prone to separation at the boundary between the internal cavity and the flow path, the flow of the cooling medium in the flow path becomes turbulent, and the flow rate of the cooling medium ejected from the opening of the cooling hole may decrease. In contrast, according to the structure of [6], the possibility of flow separation of the cooling medium when it flows from the internal cavity into the flow path can be reduced, thus reducing the possibility of a decrease in the flow rate of the cooling medium ejected from the opening of the cooling hole, and suppressing the adverse effects on the cooling effect on the blade wall of the turbine blade.

[0150] [7] In another embodiment, the turbine blade is the turbine blade of [5], wherein,

[0151] In each of the plurality of protrusions 52, a boundary region 74 is formed connecting the first region 72 and the second region 73. The angle between the boundary region 74 and the first region 72 is set as θ1, and the angle between the boundary region 74 and the second region 73 is set as θ2. Then 180°<θ1≤270° and 90°≤θ2<180°.

[0152] According to this structure, when the crossflow flows from the second region into the first region, the flow direction of the crossflow changes, thus suppressing the influence of the crossflow on the cooling medium ejected from the opening in the first region. Therefore, it can suppress the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0153] [8] In another embodiment, the turbine blade is any one of [1] to [7], wherein,

[0154] If the cooling hole formed at the position closest to the discharge hole 64 in the longitudinal direction among the plurality of cooling holes 55 is designated as the first cooling hole 55a.

[0155] The plurality of protrusions 52 respectively include:

[0156] At least including the first region 72 of the opposing surface 71 of the opening 58a of the first cooling hole 55a; and

[0157] The second region 73 of the opposing surface 71, including the opening 58 of the other cooling holes 55,

[0158] In each of the plurality of protrusions 52, between an opening 58b formed in at least one opening 58 in the first region 72 at a position furthest from the discharge hole 64 in the longitudinal direction and an opening 58c formed in at least one opening 58 in the second region 73 at a position closest to the discharge hole 64 in the longitudinal direction, a protrusion 80 is provided, including a surface 80a facing each other in the longitudinal direction when the first region 72 is viewed from the second region 73.

[0159] According to this structure, since the crossflow collides with the protrusion when it flows from the second region to the first region, the flow direction of the crossflow changes, thereby suppressing the influence of the crossflow on the cooling medium ejected from the opening in the first region. Therefore, it can suppress the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0160] [9] In another embodiment, the turbine blade is any one of [1] to [8], wherein,

[0161] If the cooling hole formed at the position closest to the discharge hole 64 in the longitudinal direction among the plurality of cooling holes 55 is designated as the first cooling hole 55a, then the plurality of protrusions 52 respectively include:

[0162] At least including the first region 72 of the opposing surface 71 of the opening 58a of the first cooling hole 55a; and

[0163] The second region 73 of the opposing surface 71, including the opening 58 of the other cooling holes 55,

[0164] The opening area of ​​the opening 58 in the first region 72 is greater than the opening area of ​​the opening 58 in the second region 73.

[0165] According to this structure, since the flow rate of the cooling medium ejected from the opening in the first region is greater than that of the cooling medium ejected from the opening in the second region, even if the crossflow between the first region and the inner surface locally increases and the cooling efficiency of the blade wall may decrease, the possibility of the decrease in cooling efficiency can be compensated by increasing the flow rate of the cooling medium ejected toward the inner surface opposite to the first region. In addition, compared with the flow of the cooling medium ejected from the opening in the second region, the flow of the cooling medium ejected from the opening in the first region has a larger cross-sectional area of ​​flow cut off in the direction orthogonal to the flow direction, so it is not easy to bend through the crossflow. Therefore, it is possible to suppress the adverse effects of the locally increased crossflow on the cooling effect of the turbine blade wall.

[0166]

[10] In another embodiment, the turbine blade is any one of [1] to [9], wherein,

[0167] If the cooling hole formed at the position closest to the discharge hole 64 in the longitudinal direction among the plurality of cooling holes 55 is designated as the first cooling hole 55a, then the plurality of protrusions 52 respectively include:

[0168] At least including the first region 72 of the opposing surface 71 of the opening 58a of the first cooling hole 55a; and

[0169] The second region 73 of the opposing surface 71, including the opening 58 of the other cooling holes 55,

[0170] If the length of each of the plurality of protrusions 52 in a direction orthogonal to the length direction is defined as the width.

[0171] In each of the plurality of protrusions 52, the width W1 of the portion including the first region 72 is smaller than the width W2 of the portion including the second region 73.

[0172] According to this structure, since the width of the recovery space between the first regions of adjacent protrusions is greater than the width of the recovery space between the second regions of adjacent protrusions, the crossflow flowing between the first region and the inner surface of the blade wall can easily flow into the recovery space, thus suppressing the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0173]

[11] In another embodiment, the turbine blade is any one of [1] to

[10] , wherein,

[0174] In each of the plurality of protrusions 52, the two end edges 71c, 71d of the opposing surface 71 in a direction orthogonal to the length direction are chamfered.

[0175] According to this structure, compared with the case where the two end edges of the opposing surface are not chamfered, the crossflow is more likely to flow into the recovery space, thus suppressing the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0176]

[12] Another method involves turbine blades from any of [1] to

[10] , wherein,

[0177] If the cooling hole formed at the position closest to the discharge hole 64 in the longitudinal direction among the plurality of cooling holes 55 is designated as the first cooling hole 55a, then the plurality of protrusions 52 respectively include:

[0178] At least including the first region 72 of the opposing surface 71 of the opening 58a of the first cooling hole 55a; and

[0179] The second region 73 of the opposing surface 71, including the opening 58 of the other cooling holes 55,

[0180] In the first region 72 of each of the plurality of protrusions 52, the two end edges 71c, 71d of the opposing surface 71 in a direction orthogonal to the length direction are chamfered.

[0181] According to this structure, compared with the case where the two end edges of the first region of the opposing surface are not chamfered, the crossflow can easily flow into the recovery space, thus suppressing the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0182]

[13] Another method involves turbine blades of [7], wherein,

[0183] The boundary region 74 protrudes toward the second region 72 from its two end edges 74c and 74d in a direction orthogonal to the length direction.

[0184] According to this structure, since the crossflow flows along the boundary region and into the recovery space on both sides of the protrusion, the crossflow flowing into the first region and the inner surface of the blade wall is reduced, thus suppressing the adverse effects of large local crossflow on the cooling effect of the turbine blade wall.

[0185] Symbol Explanation

[0186] 24-Fixed blade (turbine blade), 26-Rotating blade (turbine blade), 34-Blade wall, 34a-(Blade wall)Inner surface, 34b-(Blade wall)Tip edge, 34c-(Blade wall)Hub edge, 38-Outer shroud, 40-Inner shroud, 50-Space, 51-Insertion, 52-Spur, 52c-(Spur)End, 52d-(Spur)End, 53-Recovery space, 54-Flow path, 54a-Inner end face, 54a1-(Inner end face)First end edge, 54a2-(Inner end face)Second end edge, 54b-(Spur)Outer surface, 54b1-(Outer surface)First connecting edge, 54b2-(Outer surface) 2nd connecting edge, 55-cooling hole, 55a-1st cooling hole, 56-internal cavity, 58-opening, 58a-(the opening of the first cooling hole), 58b-(the opening formed at the position furthest from the discharge hole), 58c-(the opening formed at the position closest to the discharge hole), 59-insertion body, 59a1-(the outer surface of the insertion body), 59b1-(the outer surface of the insertion body), 60-protection periphery flow path, 63-recovery flow path, 64-discharge hole, 71-opposing surface, 72-1st region, 73-2nd region, 74-boundary region, 74c-(the end edge of the boundary region), 74d-(the end edge of the boundary region), 80-protrusion, 80a-(the surface of the protrusion).

Claims

1. A turbine blade comprising: Blade wall; and The insert is inserted into the space formed inside the blade wall, wherein... An internal cavity communicating with the outside of the turbine blade is formed inside the main body of the insert. Multiple protrusions are formed on the outer surface of the insert body, protruding toward the inner surface of the blade wall and having opposing surfaces that face the inner surface of the blade wall. The plurality of protrusions are respectively formed with: The flow path communicates with the internal cavity; and Multiple cooling holes, communicating with the flow path and opening on the opposing surface, are arranged along the length direction of each of the multiple protrusions. A retraction space is defined between two adjacent protrusions among the plurality of protrusions. 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 protrusion in the longitudinal direction, or between the blade tip-side edge of the blade wall and the blade tip-side end of the protrusion. A discharge port is formed on the blade wall, connecting the recovery flow path to the outside of the turbine blade.

2. The turbine blade according to claim 1, wherein, Of the two ends of each of the plurality of protrusions along its length direction, the outer surface of the end facing the recycling flow path includes: The first connecting edge is connected to the outer surface of the insert body portion; and The second connecting edge connects to the opposing surface. Of the first connecting edge and the second connecting edge, at least the second connecting edge is located in the length direction at a position further away from the blade tip edge of the blade wall than the hub-side edge of the blade wall, or further away from the hub-side edge than the blade tip edge. The outer surface is a surface that is curved in a way that is recessed in the longitudinal direction toward the side opposite to the recycling flow path.

3. The turbine blade according to claim 1, wherein, Of the two ends of each of the plurality of protrusions along its length direction, the outer surface of the end facing the recycling flow path includes: The first connecting edge is connected to the outer surface of the insert body portion; and The second connecting edge connects to the opposing surface. Of the first connecting edge and the second connecting edge, at least the second connecting edge is located in the length direction at a position further away from the blade tip edge of the blade wall than the hub-side edge of the blade wall, or further away from the hub-side edge than the blade tip edge. The outer surface is a flat surface.

4. The turbine blade according to any one of claims 1 to 3, wherein, One of the outer and inner shields respectively provided on the blade tip side edge and hub side edge of the blade wall forms a shield periphery flow path extending along its periphery. The recycling flow path is connected to the peripheral flow path of the protective cover via the discharge hole.

5. The turbine blade according to any one of claims 1 to 3, wherein, In each of the plurality of protrusions, if the cooling hole formed at the position closest to the discharge hole in the longitudinal direction is designated as the first cooling hole, then the first region of the opposing surface including at least the opening of the first cooling hole protrudes further toward the inner surface of the blade wall than the second region of the opposing surface including the openings of the other cooling holes.

6. The turbine blade according to any one of claims 1 to 3, wherein, Inside the flow path of each of the plurality of protrusions, if the face facing the recovery flow path when viewed along the length direction is defined as the inner end face... The internal end face, in the direction from the internal cavity toward the opposing surface, includes the end edge on the internal cavity side, i.e., the first end edge, and the end edge on the opposing surface side, i.e., the second end edge. The inner end face is configured to move away from the discharge hole in the length direction from the first end edge toward the second end edge.

7. The turbine blade according to claim 5, wherein, In each of the plurality of protrusions, a boundary region connecting the first region and the second region is formed. The angle between the boundary region and the first region is set as θ1, and the angle between the boundary region and the second region is set as θ2. Then 180°<θ1≤270° and 90°≤θ2<180°.

8. The turbine blade according to any one of claims 1 to 3, wherein, If the cooling hole formed at the position closest to the discharge hole in the length direction among the plurality of cooling holes is designated as the first cooling hole, then the plurality of protrusions respectively include: At least including the first region of the opposing surface of the opening of the first cooling hole; and The second region of the opposing surface, including the openings of other cooling holes, In each of the plurality of protrusions, between an opening formed at the position furthest from the discharge hole in the length direction in at least one opening in the first region and an opening formed at the position closest to the discharge hole in the length direction in at least one opening in the second region, a protrusion comprising a face opposite to the first region when viewed from the second region in the length direction is provided.

9. The turbine blade according to any one of claims 1 to 3, wherein, If the cooling hole formed at the position closest to the discharge hole in the length direction among the plurality of cooling holes is designated as the first cooling hole, then the plurality of protrusions respectively include: At least including the first region of the opposing surface of the opening of the first cooling hole; and The second region of the opposing surface, including the openings of other cooling holes, The opening area of ​​the opening in the first region is greater than the opening area of ​​the opening in the second region.

10. The turbine blade according to any one of claims 1 to 3, wherein, If the cooling hole formed at the position closest to the discharge hole in the longitudinal direction among the plurality of cooling holes is designated as the first cooling hole, then the plurality of protrusions respectively include At least including the first region of the opposing surface of the opening of the first cooling hole; and The second region of the opposing surface, including the openings of other cooling holes, If the length of each of the plurality of protrusions in a direction orthogonal to the length direction is defined as the width. In each of the plurality of protrusions, the width of the portion including the first region is smaller than the width of the portion including the second region.

11. The turbine blade according to any one of claims 1 to 3, wherein, In each of the plurality of protrusions, the two end edges of the opposing surfaces in a direction orthogonal to the length direction are chamfered.

12. The turbine blade according to any one of claims 1 to 3, wherein, If the cooling hole formed at the position closest to the discharge hole in the length direction among the plurality of cooling holes is designated as the first cooling hole, then the plurality of protrusions respectively include: At least including the first region of the opposing surface of the opening of the first cooling hole; and The second region of the opposing surface, including the openings of other cooling holes, In the first region of each of the plurality of protrusions, the two end edges of the opposing surfaces in a direction orthogonal to the length direction are chamfered.

13. The turbine blade according to claim 7, wherein, The boundary region protrudes towards the second region from its two end edges in a direction orthogonal to the length direction.

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