Turbine blades and gas turbines

Abstract

A turbine blade comprises a blade body, a plurality of cooling passages extending in the blade height direction inside the blade body and connected to each other via folded portions, and a bypass portion that is provided in a partition wall portion partitioning a pair of adjacent cooling passages among the plurality of cooling passages and that allows the pair of cooling passages to communicate with each other. The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of a cooling fluid. The turbine blade is provided with: a plurality of cooling holes that are formed in the blade body so as to be arranged along the blade height direction, that communicate with the downstream passage, and that open in the surface of the blade body; a plurality of turbulators provided on the inner wall surface of the downstream passage and arranged along the blade height direction; or a thermal barrier coating that covers the surface of the blade body. The value of a parameter indicating a characteristic of the plurality of cooling holes, the plurality of turbulators, or the thermal barrier coating is different in the blade height direction between an upstream region positioned farther upstream with respect to the flow of the cooling fluid in the downstream passage than to a position corresponding to the bypass portion, and a downstream region positioned downstream of the upstream region with respect to the flow of the cooling fluid in the downstream passage.

Description

[Technical field]

[0001] The present disclosure relates to turbine blades and gas turbines. This application claims priority based on Patent Application No. 2021-198469, filed with the Japan Patent Office on December 7, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] It is known that in turbine blades of gas turbines and the like, the turbine blades exposed to high-temperature gas flow, etc., are cooled by flowing a cooling fluid through a serpentine flow path (meandering flow path) formed inside the turbine blade. In such turbine blades, cooling holes or turbulators, etc. for effectively cooling the turbine blade with the cooling fluid, and a thermal barrier coating, etc. for suppressing heat input to the turbine blade may be provided.

[0003] For example, Patent Document 1 discloses a gas turbine blade with a serpentine flow passage provided inside the blade body. A plurality of cooling holes are provided at the trailing edge of this turbine blade to cool the trailing edge of the turbine blade using a cooling fluid flowing through the serpentine flow passage. In addition, a plurality of fins (turbulators) are provided on the inner wall surface of the cooling passage that forms the serpentine flow passage of this turbine blade to promote turbulence of the flow of the cooling fluid in the cooling passage. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 9-507550 [Patent Document 2] JP 2017-150475 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the temperature of the cooling fluid increases toward the downstream side of the serpentine flow path, and the cooling capacity of the cooling fluid decreases. Therefore, it has been proposed to provide a bypass section in the serpentine flow path and supply the cooling fluid before its temperature increases to a portion where cooling is desired to be strengthened. By providing the bypass section in this way, a relatively low-temperature cooling fluid can be supplied to the serpentine flow path downstream of the bypass section, but the temperature difference of the cooling fluid before and after the bypass section becomes large. For this reason, the cooling fluid may become overcooled downstream of the bypass section, or may become insufficiently cooled upstream of the bypass section. When the turbine blades are overcooled, the efficiency of use of the cooling air may decrease, and the efficiency of the turbine as a whole may decrease. Furthermore, when the turbine blades are insufficiently cooled, the turbine blades may be damaged.

[0006] In view of the above circumstances, at least one embodiment of the present invention has an object to provide a turbine blade and a gas turbine that can suppress overcooling or insufficient cooling of the turbine blade that occurs when a bypass portion is provided in a serpentine flow passage. [Means for solving the problem]

[0007] A turbine blade according to at least one embodiment of the present invention comprises: The wing body and a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is a plurality of cooling holes formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; A plurality of turbulators provided on an inner wall surface of the downstream passage and arranged along the blade height direction, or A thermal barrier coating covering the surface of the wing body. Equipped with In the blade height direction, an upstream region located upstream of a position corresponding to the bypass portion in terms of the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in terms of the flow of the cooling fluid in the downstream passage, have different values ​​of parameters indicating characteristics of the plurality of cooling holes, the plurality of turbulators, or the thermal barrier coating.

[0008] Moreover, a gas turbine according to at least one embodiment of the present invention includes: The turbine blade as described above; a combustor for generating combustion gases flowing through a combustion gas passage in which the turbine blades are disposed. Effect of the Invention

[0009] According to at least one embodiment of the present invention, there is provided a turbine blade and a gas turbine capable of suppressing overcooling or insufficient cooling of the turbine blade caused by the provision of a bypass portion in a serpentine flow passage. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of a gas turbine according to an embodiment; [Diagram 2] 1 is a schematic cross-sectional view of a turbine blade in a blade height direction according to an embodiment; FIG. [Diagram 3] FIG. 3 is a view showing a cross section AA of the turbine blade in FIG. 2. [Figure 4] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic cross-sectional view showing an enlarged leading edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 6] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 7] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 8] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 9] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 10] FIG. 2 is a schematic cross-sectional view showing an enlarged leading edge side portion of a turbine blade according to an embodiment of the present invention. [Figure 11] FIG. 2 is a schematic cross-sectional view showing an enlarged view of a trailing edge side portion of a turbine blade according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0012] (Gas turbine configuration) FIG. 1 is a schematic diagram of a gas turbine as an example of a turbine to which a turbine blade according to some embodiments is applied.

[0013] As shown in FIG. 1, the 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.

[0014] 1, the compressor 2 includes a plurality of stator vanes 16 fixed to the compressor casing 10 side, and a plurality of rotor blades 18 implanted in the rotor 8 so as to be arranged alternately with respect to the stator vanes 16. 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 rotor blades 18, becoming high-temperature, high-pressure compressed air.

[0015] The combustor 4 is configured to receive fuel and the compressed air generated by the compressor 2, and the fuel is combusted in the combustor 4 to generate combustion gas, which is a working fluid for the turbine 6. As shown in Fig. 1, the gas turbine 1 has a plurality of combustors 4 arranged in a casing 20 along the circumferential direction with a rotor 8 as the center.

[0016] The turbine 6 has a combustion gas passage 28 formed by the turbine casing 22, and includes a plurality of stator vanes 24 and rotor blades 26 provided in the combustion gas passage 28. The stator vanes 24 are fixed to the turbine casing 22 side, and the plurality of stator vanes 24 arranged along the circumferential direction of the rotor 8 constitute a stator vane row. The rotor blades 26 are implanted in the rotor 8, and the 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.

[0017] In the turbine 6, the combustion gas from the combustor 4 flows into a combustion gas passage 28 and passes through the plurality of stator vanes 24 and the plurality of rotor blades 26, thereby rotating and driving the rotor 8. Note that a generator may be connected to the rotor 8 so that the generator is driven by the turbine 6 to generate electric power. After driving the turbine 6, the combustion gas is exhausted to the outside via an exhaust chamber 30.

[0018] In some embodiments, at least one of the rotor blades 26 and the stator blades 24 of the turbine 6 is a turbine blade 40 described below. In the following, the rotor blades 26 as the turbine blades 40 will be mainly described with reference to the drawings, but the same description can be basically applied to the stator blades 24 as the turbine blades 40.

[0019] (Turbine blade configuration) Fig. 2 is a schematic cross-sectional view along the blade height direction of a turbine blade 40 (rotor blade 26) according to one embodiment, and Fig. 3 is a view showing a cross section of the turbine blade 40 taken along line AA in Fig. 2. The arrows in the figure indicate the direction of flow of a cooling fluid. Note that a thermal barrier coating 86 (see Fig. 3) is omitted in Fig. 2.

[0020] As shown in Figures 2 and 3, a turbine blade 40 (rotor blade 26) according to one embodiment includes a blade body 42, a platform 80, and a blade root 82 that is integral with the platform 80 and embedded in the rotor 8 (see Figure 1).

[0021] The blade body 42 is provided so as to extend along the radial direction of the rotor 8 (hereinafter, sometimes simply referred to as the "radial direction") and has a base end 50 fixed to the platform 80 and a tip 48 located on the opposite side (radially outer side) of the base end 50 in the blade height direction (radial direction of the rotor 8). The blade body 42 includes a top plate 49 forming a tip side portion including the tip 48 of the blade body 42. The blade body 42 of the rotor blade 26 also has a leading edge 44 and a trailing edge 46 extending from the base end 50 to the tip 48, and the blade surface of the blade body 42 includes a pressure surface (pressure surface) 56 and a suction surface (suction surface) 58 each extending along the blade height direction between the base end 50 and the tip 48.

[0022] 2 and 3, a plurality of cooling passages 60a to 60f (hereinafter collectively referred to as cooling passages 60) extending along the blade height direction are provided inside the blade body 42. In the illustrated embodiment, the cooling passages 60a to 60f are arranged in this order from the leading edge 44 side to the trailing edge 46 side.

[0023] The multiple cooling passages 60 are connected to each other via turn-back portions 59 located on the tip end 48 side or the base end 50 side to form serpentine flow paths (snake flow paths) 61 (61A, 61B). A pair of adjacent cooling passages 60 among the multiple cooling passages 60 is separated by a partition wall portion 32 extending along the blade height direction. The flow direction of the cooling fluid flowing through the serpentine flow paths 61 (61A, 61B) is turned back at the turn-back portions 59 to the opposite direction in the blade height direction.

[0024] 2 and 3, among the cooling passages 60a to 60c, the adjacent cooling passages 60a and 60b, and the adjacent cooling passages 60b and 60c are connected via turn-back portions 59. These cooling passages 60a to 60c form a serpentine flow passage 61A on the leading edge side.

[0025] 2 and 3, among the cooling passages 60d to 60f, the adjacent cooling passages 60d and 60e, and the adjacent cooling passages 60e and 60f are connected via turn-back portions 59. These cooling passages 60d to 60f form a serpentine flow passage 61B on the trailing edge side.

[0026] A cooling fluid (e.g., air) for cooling the turbine blade 40 is supplied to the serpentine flow passages 61 (61A, 61B). In the illustrated embodiment, internal flow passages 84A, 84B are provided inside the blade root 82, and the most upstream cooling passages 60c, 60d of the multiple cooling passages 60 forming the serpentine flow passages 61A, 61B are connected to the above-mentioned internal flow passages 84A, 84B, respectively. A cooling fluid from the outside is supplied to the serpentine flow passages 61A, 61B via the internal flow passages 84A, 84B, respectively.

[0027] The cooling fluid introduced into the serpentine flow passages 61A, 61B flows sequentially downstream through the multiple cooling passages 60 that form the serpentine flow passages 61A, 61B. The cooling fluid flowing through the cooling passages 60a, 60f that are furthest downstream in the flow direction of the cooling fluid among the multiple cooling passages 60 flows out into the combustion gas passage 28 outside the turbine blade 40 through outlet openings 64A, 64B provided on the tip 48 side of the blade body 42.

[0028] In this manner, by supplying a cooling fluid to the serpentine flow passage 61, the blade body 42 that is provided in the combustion gas passage 28 of the turbine 6 and exposed to high-temperature combustion gas is cooled.

[0029] In some embodiments, the turbine blade 40 has a plurality of cooling holes formed in the blade body 42 arranged along the blade height direction, communicating with the cooling passage 60 and opening to the surface of the blade body 42 .

[0030] In the exemplary embodiment shown in Figures 2 and 3, the turbine blade 40 is provided with a plurality of cooling holes 72 (72a to 72c) that are formed in the blade body 42 so as to be arranged along the blade height direction, communicate with the cooling passage 60a (downstream passage 66 described later) located closest to the leading edge, and open to the surface of the leading edge of the blade body 42.

[0031] A portion of the cooling fluid flowing through the cooling passage 60a passes through the cooling holes 72 and flows out from the opening in the leading edge portion of the blade body 42 into the combustion gas passage 28 outside the turbine blade 40. When the cooling fluid thus flows along the outer surface of the turbine blade 40, the cooling fluid forms a film boundary layer (a film-like cooling medium flow) on the outer surface. This film boundary layer suppresses the transfer of heat (heat input to the turbine blade 40) from the combustion gas flowing through the combustion gas passage 28 to the blade body 42. In addition, the cooling fluid passing through the cooling holes 72 convectively cools the leading edge portion, including the leading edge 44, of the blade body 42.

[0032] In the exemplary embodiment shown in Figures 2 and 3, the turbine blade 40 is provided with a plurality of cooling holes 70 that are formed in the blade body 42 so as to be arranged along the blade height direction, communicate with the cooling passage 60f (downstream passage 66 described below) located on the most trailing edge side, and open to the surface of the trailing edge of the blade body 42.

[0033] A portion of the cooling fluid flowing through the cooling passage 60f passes through the cooling holes 70 and flows out from the opening in the trailing edge portion of the blade body 42 into the combustion gas passage 28 outside the turbine blade 40. In this manner, the cooling fluid passes through the cooling holes 70, thereby convectively cooling the trailing edge portion, including the trailing edge 46, of the blade body 42.

[0034] In some embodiments, the turbine blade 40 includes a plurality of turbulators 34 provided on the inner wall surface 63 of the cooling passage 60 and arranged along the blade height direction. In the exemplary embodiment shown in Figures 2 and 3, the inner wall surface 63 of each of the plurality of cooling passages 60 is provided with a plurality of rib-shaped turbulators 34 protruding from the inner wall surface 63.

[0035] When the turbulators 34 are provided on the inner wall surface 63 of the cooling passage 60, flow disturbance such as generation of vortexes is promoted near the turbulators 34 when the cooling fluid flows through the cooling passage 60. This promotes cooling of the turbine blades 40 by the cooling fluid flowing through the cooling passage 60.

[0036] In some embodiments, the turbine blade 40 includes a thermal barrier coating 86 (see FIG. 3) covering the surfaces (pressure surface 56 and suction surface 58) of the blade body 42. The thermal barrier coating 86 provided on the surface of the turbine blade 40 suppresses heat transfer (heat input to the turbine blade 40) from the combustion gas flowing through the combustion gas passage 28 to the blade body 42.

[0037] The thermal barrier coating 86 may include a ceramic layer formed from a ceramic and a bond layer formed from an oxidation-resistant metal or the like and disposed between the ceramic layer and the blade body 42. The thermal barrier coating 86 may be applied by thermal spraying.

[0038] While the exemplary embodiment shown in Figures 2-3 includes a plurality of cooling holes 72 at the leading edge, a plurality of cooling holes 70 at the trailing edge, turbulators 34, and a thermal barrier coating 86, in some embodiments, the turbine blade 40 may include any one or more of a plurality of cooling holes 72 at the leading edge, a plurality of cooling holes 70 at the trailing edge, turbulators 34, or a thermal barrier coating 86.

[0039] 2, in some embodiments, the turbine blade 40 includes a bypass section 36 provided in a partition section 32 that separates an upstream passage 65 and a downstream passage 66, which are a pair of adjacent cooling passages 60 among the multiple cooling passages 60 that form a serpentine flow passage 61, and that connects the upstream passage 65 and the downstream passage 66 to each other. Here, the downstream passage 66 is the cooling passage 60 that is located next to the upstream passage 65 among the multiple cooling passages 60, and is the cooling passage 60 that is located downstream of the upstream passage 65 with respect to the flow of cooling fluid that flows through the multiple cooling passages 60 (serpentine flow passage 61). The bypass section 36 may be a hole or a slit provided in the partition section 32.

[0040] 2, the turbine blade 40 includes a bypass section 36 provided in a partition wall section 32 that separates adjacent cooling passage 60b (upstream passage 65) and cooling passage 60a (downstream passage 66) of the multiple cooling passages 60a to 60c that form the serpentine flow passage 61A on the leading edge side. The cooling passage 60b (upstream passage 65) and the cooling passage 60a (downstream passage 66) are communicated with each other via the bypass section 36.

[0041] 2, the turbine blade 40 includes a bypass portion 36 provided in the partition portion 32 that separates adjacent cooling passage 60e (upstream passage 65) and cooling passage 60f (downstream passage 66) of the multiple cooling passages 60d to 60f that form the serpentine flow passage 61B on the trailing edge side. The cooling passage 60e (upstream passage 65) and the cooling passage 60f (downstream passage 66) are communicated with each other via the bypass portion 36.

[0042] In some embodiments, the values ​​of parameters characteristic of the plurality of cooling holes 70 or 72, the plurality of turbulators 34, or the thermal barrier coating 86, or the average values ​​of the parameters, are different between an upstream region R1 located upstream of a position corresponding to the bypass portion 36 in the blade height direction in terms of the flow of cooling fluid in the downstream passage 66 (cooling passage 60a or 60f) and a downstream region R2 located downstream of the upstream region R1 in terms of the flow of cooling fluid in the downstream passage 66 (cooling passage 60a or 60f). Examples of the parameters will be described later.

[0043] 2 and the exemplary embodiments shown in Figures 4 to 10 described later, the values ​​of any of the above parameters are different between an upstream region R1 located upstream of a position HB of the bypass section 36 in the blade height direction and a downstream region R2 located downstream of the position HB of the bypass section 36 in the blade height direction (i.e., the boundary between the upstream region R1 and the downstream region R2 is the position HB of the bypass section 36 in the blade height direction). However, for example, as in the embodiment shown in Figure 11 described later, the boundary between the upstream region R1 and the downstream region R2 may be shifted from the position HB of the bypass section 36 in the blade height direction.

[0044] In general, the temperature of the cooling fluid supplied to the serpentine flow passage 61 increases toward the downstream side, and the cooling capacity of the cooling fluid decreases. In this regard, in the turbine blade 40 having the above-mentioned configuration, the adjacent upstream passage 65 and downstream passage 66 are communicated via the bypass section 36, so that a cooling fluid at a relatively low temperature before the temperature increases can be supplied to the region downstream of the bypass section 36 in the downstream passage 66 (downstream region R2). Therefore, the blade body 42 in the vicinity of the downstream region R2 can be effectively cooled. In addition, in the turbine blade 40 having the above-mentioned configuration, parameters indicating characteristics of the multiple cooling holes 70 or 72, the multiple turbulators 34, or the thermal barrier coating 86 are different between the upstream region (upstream region R1) and the downstream region (downstream region R2) of the bypass section 36 in the downstream passage 66. Therefore, it is possible to make a difference between the upstream region R1 and the downstream region R2 in the downstream passage 66 in the amount of heat removed from the turbine blade 40 by the cooling fluid, or the amount of heat input to the turbine blade 40 from the gas (combustion gas, etc.) flowing through the combustion gas passage 28 in which the turbine blade 40 is arranged. Therefore, it is possible to suppress overcooling in the downstream region R2 or insufficient cooling in the upstream region R1 of the blade body 42 in the vicinity of the downstream passage 66. In other words, according to the turbine blade 40 having the above-mentioned configuration, the provision of the bypass section 36 makes it possible to effectively cool the turbine blade 40, and also makes it possible to suppress overcooling or insufficient cooling of the turbine blade 40 that would otherwise occur due to the installation of the bypass section 36.

[0045] Here, specific examples of the above-mentioned parameters will be described. Fig. 4 and Fig. 6 to Fig. 9 are schematic cross-sectional views each showing an enlarged view of a trailing edge side portion of a turbine blade 40 according to an embodiment. Fig. 5 and Fig. 10 are schematic cross-sectional views each showing an enlarged view of a leading edge side portion of a turbine blade 40 according to an embodiment. Note that some parameters will be described using either the diagram of the trailing edge side portion of the turbine blade 40 (Figs. 6 to 9) or the diagram of the leading edge side portion (Fig. 10), but the same description can be given for the other of the leading edge side portion or the trailing edge side portion of the turbine blade 40.

[0046] In some embodiments, the above-mentioned parameter may be the pitch Ph in the blade height direction of a pair of adjacent cooling holes 70 or 72 among the multiple cooling holes 70 or 72. In some embodiments, the pitch Ph2 in the downstream region R2 of the pair of adjacent cooling holes 70 or 72 is larger than the pitch Ph1 in the upstream region R1, as shown in Fig. 4 or 5, for example. In this case, the diameters of the multiple cooling holes 70 or 72 arranged along the blade height direction may be the same.

[0047] The pitch of a pair of adjacent cooling holes in the blade height direction is the distance in the blade height direction between the centers of a pair of adjacent cooling holes.

[0048] In some embodiments, the above-mentioned parameter may be a diameter D of the cooling holes 70 or 72. In some embodiments, for example, as shown in Fig. 6, a diameter D2 in a downstream region R2 of the cooling holes 70 or 72 is smaller than a diameter D1 in an upstream region R1. In this case, the pitch in the blade height direction of the cooling holes 70 or 72 arranged along the blade height direction may be the same.

[0049] The diameter of a cooling hole may be the equivalent diameter (hydraulic diameter) of the cooling hole.

[0050] In some embodiments, the above-mentioned parameter may be the opening density of the plurality of cooling holes 70 or 72. In some embodiments, the opening density in the downstream region R2 is less than the opening density in the upstream region R1.

[0051] Here, the opening density of the multiple cooling holes may be the ratio Ph / D of the pitch Ph of the cooling holes 70 in the blade height direction to the diameter D of the cooling holes, or the ratio S / Ph of the wetted perimeter S of the opening end of the cooling hole on the surface of the blade body 42 (i.e., the perimeter of the opening end on the surface of the blade body 42) to the pitch Ph of the cooling holes in the blade height direction, or the number of cooling holes per unit length of the blade body 42 in the blade height direction may be used.

[0052] In the above-described embodiment, the pitch Ph in the blade height direction of the multiple cooling holes 70 or 72 that communicate with the downstream passage 66 and open to the surface of the blade body 42 is larger in the downstream region R2 than in the upstream region R1. Alternatively, the diameter D of the multiple cooling holes 70 or 72 is smaller in the downstream region R2 than in the upstream region R1. Alternatively, the opening density of the multiple cooling holes 70 or 72 is smaller in the downstream region R2 than in the upstream region R1.

[0053] Therefore, the amount of heat removed from the turbine blade 40 by the cooling fluid in the downstream region R2 can be made smaller than when the pitch Ph, diameter D, or opening density is the same in the downstream region R2 and the upstream region R1. Alternatively, the amount of heat removed from the turbine blade 40 by the cooling fluid in the upstream region R1 can be made larger than when the pitch Ph, diameter D, or opening density is the same in the downstream region R2 and the upstream region R1. Therefore, for the blade body 42 in the vicinity of the downstream passage 66, overcooling in the downstream region R2 or insufficient cooling in the upstream region R1 can be suppressed.

[0054] In some embodiments, the above-mentioned parameter may be the surface roughness of the inner wall surface 71 (see FIG. 4) of the plurality of cooling holes 70 or 72. The surface roughness may be an arithmetic mean roughness Ra. In some embodiments, the surface roughness in the downstream region R2 of the plurality of cooling holes 70 or 72 is smaller than the surface roughness in the upstream region R1.

[0055] In the above embodiment, the surface roughness of the inner wall surface 71 of the plurality of cooling holes 70 or 72 that communicate with the downstream passage 66 and open on the surface of the blade body 42 is smaller in the downstream region R2 than in the upstream region R1. Therefore, the amount of heat removed from the turbine blade 40 by the cooling fluid in the downstream region R2 can be made smaller than when the surface roughness of the inner wall surface 71 of the plurality of cooling holes 70 or 72 is the same in the downstream region R2 and the upstream region R1. Alternatively, the amount of heat removed from the turbine blade 40 by the cooling fluid in the upstream region R1 can be made larger than when the surface roughness of the inner wall surface 71 of the plurality of cooling holes 70 or 72 is the same in the downstream region R2 and the upstream region R1. Therefore, for the blade body 42 near the downstream passage 66, overcooling in the downstream region R2 or insufficient cooling in the upstream region R1 can be suppressed.

[0056] In some embodiments, multiple turbulators 34 may be provided such that the heat transfer coefficient between the cooling fluid and the inner wall surface 63 of the downstream passage 66 is smaller in the downstream region R2 than in the upstream region R1.

[0057] For example, in some embodiments, the parameter may be the pitch PT in the blade height direction of the plurality of turbulators 34. In some embodiments, the pitch PT2 in the downstream region R2 of the plurality of turbulators 34 is greater than the pitch PT1 in the upstream region R1, as shown, for example, in FIG.

[0058] The pitch PT of the turbulators 34 in the blade height direction is the distance in the blade height direction between the centers of a pair of turbulators 34 adjacent to each other in the blade height direction (see FIG. 8). When the heights e of the turbulators 34 are the same, the smaller the pitch PT of the turbulators 34, the greater the heat transfer coefficient between the cooling fluid and the turbine blades 40 tends to be.

[0059] Also for example, in some embodiments, the above-mentioned parameter may be the height e of the turbulator 34 relative to the inner wall surface 63 of the downstream passage 66. In some embodiments, the height e2 of the turbulator 34 in the downstream region R2 is smaller than the height e1 in the upstream region R1, as shown in FIG.

[0060] When the pitch PT of the turbulators 34 is the same, the heat transfer coefficient between the cooling fluid and the turbine blades 40 tends to be greater as the height e of the turbulators 34 increases.

[0061] Also, for example, in some embodiments, the above-mentioned parameter may be the angle θ (where θ is equal to or greater than 0 degrees and equal to or less than 90 degrees) between the flow direction of the cooling fluid in the downstream passage 66 (shown by the straight line L1 in FIG. 9) and the extension direction of the turbulators 34. In other words, in some embodiments, the inclination angle θ of the turbulators 34 differs between the downstream region R2 and the upstream region R1.

[0062] In the above-described embodiment, the inner wall surface 63 of the downstream passage 66 is provided with a plurality of turbulators 34 arranged along the blade height direction, and the heat transfer coefficient between the inner wall surface 63 and the cooling fluid is smaller in the downstream region R2 than in the upstream region R1. For example, the pitch PT2 of the plurality of turbulators 34 in the downstream region R2 is larger than the pitch PT1 in the upstream region R1. Alternatively, the height e2 of the turbulators 34 in the downstream region R2 is smaller than the height e1 in the upstream region R1. Alternatively, the inclination angle θ2 of the turbulators 34 in the downstream region R2 is different from the inclination angle θ1 in the upstream region R1.

[0063] Therefore, the amount of heat removed from the turbine blade 40 by the cooling fluid in the downstream region R2 can be made smaller than when the above-mentioned heat transfer coefficient, the pitch PT of the turbulators 34, the height e of the turbulators 34, or the angle θ of the turbulators 34 are the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade 40 by the cooling fluid in the upstream region can be made larger than when the above-mentioned heat transfer coefficient is the same in the downstream region R2 and the upstream region R1. Therefore, for the blade body 42 in the vicinity of the downstream passage 66, overcooling in the downstream region R2 or insufficient cooling in the upstream region R1 can be suppressed.

[0064] In some embodiments, the aforementioned parameter may be the thickness T of the thermal barrier coating 86. In some embodiments, the thickness T2 of the thermal barrier coating 86 in the downstream region R2 is less than the thickness T1 of the thermal barrier coating 86 in the upstream region R1, as shown in FIG.

[0065] The thickness of the thermal barrier coating 86 may be different as described above only in a part of the surface of the turbine blade 40. For example, in a region including the leading edge 44 or the trailing edge 46 located near the downstream passage 66 (cooling passage 60a in FIG. 10) in which the bypass portion 36 is provided, the thickness T2 of the thermal barrier coating 86 in the downstream region R2 may be smaller than the thickness T1 of the thermal barrier coating 86 in the upstream region R1 as described above.

[0066] The thickness T of the thermal barrier coating 86 can be adjusted, for example, by changing the moving speed of the thermal spray gun when applying the thermal barrier coating 86. That is, the faster the moving speed of the thermal spray gun is, the thinner the thickness of the thermal barrier coating that is formed.

[0067] In the above embodiment, the thickness of the thermal barrier coating 86 covering the surface of the blade body 42 is smaller in the downstream region R2 than in the upstream region R1. Therefore, the metal temperature of the blade body 42 can be made more uniform in the blade height direction than when the thickness T of the thermal barrier coating 86 is the same in the downstream region R2 and the upstream region R1. Therefore, for the blade body 42 near the downstream passage 66, overcooling in the downstream region R2 or insufficient cooling in the upstream region R1 can be suppressed.

[0068] 11 is a schematic cross-sectional view showing an enlarged trailing edge portion of the turbine blade 40 according to one embodiment. In some embodiments, the bypass portion 36 is provided in the partition wall portion 32 that separates the cooling passage 60a or 60f (downstream passage 66) located at the most leading edge side or the most trailing edge side among the multiple cooling passages 60, from the cooling passage 60b or 60e (upstream passage 65) adjacent to the cooling passage 60a or 60f. (In the exemplary embodiment shown in FIG. 11 , the bypass portion 36 is provided in the partition portion 32 that separates the cooling passage 60f (downstream passage 66) located at the most trailing edge side from the cooling passage 60e (upstream passage 65) adjacent to the cooling passage 60f.) In the blade height direction, the values ​​of the above-mentioned parameters are different between an upstream region R1 and a downstream region R2 that are bounded by a position HB' (a position corresponding to the bypass portion 36 in the blade height direction) downstream of the position HB of the bypass portion 36 with respect to the flow of the cooling passage in the cooling passage 60a or 60f (downstream passage 66).

[0069] Among the cooling passages 60, the cooling passage 60a or 60f located closest to the leading edge or closest to the trailing edge usually has an outlet opening 64A or 64B at the downstream end (see FIG. 2). If this outlet opening 64 is large, the flow rate of the cooling fluid in the cooling passage 60f increases. In such a case, the direction of the cooling fluid (arrow Fa in FIG. 11) flowing from the upstream passage 65 through the bypass section 36 to the downstream passage 66 is largely bent downstream, and the cooling fluid is supplied to a position in the downstream passage 66 downstream of the bypass section 36.

[0070] In this regard, in the above-described embodiment, the position where the value of the parameter indicating the characteristics of the plurality of cooling holes 70 or 72, the plurality of turbulators 34, or the thermal barrier coating 86 is changed is provided downstream of the bypass portion 36. Therefore, even if the direction of the cooling fluid flowing into the downstream passage 66 is largely bent downstream as described above, it is possible to make a difference in the amount of heat removed from the turbine blade 40 by the cooling fluid, or the amount of heat input to the turbine blade 40 from the gas flowing through the combustion gas passage 28 in which the turbine blade 40 is arranged, between the upstream region (upstream region R1) and the downstream region (downstream region R2) of the position HB' (position corresponding to the bypass portion 36) on the downstream side of the bypass portion 36. Therefore, for the blade body 42 in the vicinity of the downstream passage 66, it is possible to effectively suppress overcooling in the downstream region R2 or insufficient cooling in the upstream region R1.

[0071] The contents described in each of the above embodiments can be understood, for example, as follows.

[0072] (1) At least one embodiment of the turbine blade (40) of the present invention comprises: A wing body (42); a plurality of cooling passages (60) each extending along the blade height direction inside the blade body and connected to each other via a turn-back portion (59); a bypass portion (36) provided in a partition wall portion (32) separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion (36) connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage (65) and a downstream passage (66) located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is A plurality of cooling holes (70 or 72) formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on the surface of the blade body; A plurality of turbulators (34) provided on an inner wall surface (63) of the downstream passage and arranged along the blade height direction, or A thermal barrier coating (86) covering the surface of the wing body. Equipped with In the blade height direction, values ​​of parameters indicating characteristics of the plurality of cooling holes, the plurality of turbulators or the thermal barrier coating are different between an upstream region (R1) located upstream of a position corresponding to the bypass portion in terms of the flow of the cooling fluid in the downstream passage, and a downstream region (R2) located downstream of the upstream region in terms of the flow of the cooling fluid in the downstream passage.

[0073] In the above configuration (1), the adjacent upstream and downstream passages are connected to each other via the bypass section, so that a cooling fluid at a relatively low temperature before the temperature rises can be supplied to the downstream region of the downstream passage downstream of the bypass section, thereby effectively cooling the blade body in the vicinity of the downstream region. In the configuration of (1) above, the values ​​of parameters indicating the characteristics of the cooling holes, the turbulators, or the thermal barrier coating are different between the upstream region (upstream region) and the downstream region (downstream region) of the bypass section in the downstream passage. Therefore, it is possible to make a difference between the amount of heat removed from the turbine blade by the cooling fluid, or the amount of heat input to the turbine blade from the gas (combustion gas, etc.) flowing through the gas passage in which the turbine blade is arranged, between the upstream region and the downstream region in the downstream passage. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage. That is, according to the above configuration (1), the provision of the bypass section makes it possible to effectively cool the turbine blades, and also makes it possible to suppress overcooling or insufficient cooling of the turbine blades that would otherwise occur due to the provision of the bypass section.

[0074] (2) In some embodiments, in the configuration of (1) above, The turbine blade is a plurality of cooling holes (70 or 72) formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening to a surface of the blade body; The opening density of the plurality of cooling holes is smaller in the downstream region than in the upstream region.

[0075] According to the above configuration (2), the opening density of the multiple cooling holes that communicate with the downstream passage and open on the surface of the blade body is smaller in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the above-mentioned opening density is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the above-mentioned opening density is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0076] (3) In some embodiments, in the configuration of (1) or (2), The turbine blade is a plurality of cooling holes formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; A pitch (Ph) in the blade height direction between a pair of cooling holes adjacent in the blade height direction is larger in the downstream region than in the upstream region.

[0077] According to the above configuration (3), the pitch in the blade height direction of the multiple cooling holes that communicate with the downstream passage and open to the surface of the blade body is larger in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the pitch of the multiple cooling holes is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the pitch of the multiple cooling holes is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0078] (4) In some embodiments, in any one of the configurations (1) to (3) above, The turbine blade is a plurality of cooling holes formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; The diameter (D) of the cooling holes is smaller in the downstream region than in the upstream region.

[0079] According to the above configuration (4), the diameter of the cooling holes that communicate with the downstream passage and open to the surface of the blade body is smaller in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the diameters of the cooling holes are the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the diameters of the cooling holes are the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0080] (5) In some embodiments, in any one of the configurations (1) to (4) above, The turbine blade is a plurality of cooling holes formed in the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; The surface roughness of the inner wall surfaces of the plurality of cooling holes is smaller in the downstream region than in the upstream region.

[0081] According to the above configuration (5), the surface roughness of the inner wall surface of the multiple cooling holes that communicate with the downstream passage and open on the surface of the blade body is smaller in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the surface roughness of the inner wall surfaces of the multiple cooling holes is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the surface roughness of the inner wall surfaces of the multiple cooling holes is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0082] (6) In some embodiments, in any of the configurations (1) to (5) above, The turbine blade is a plurality of turbulators (34) provided on an inner wall surface (63) of the downstream passage and arranged along the blade height direction, The plurality of turbulators are provided so that a heat transfer coefficient between the cooling fluid and the inner wall surface of the downstream passage is smaller in the downstream region than in the upstream region.

[0083] According to the above configuration (6), a plurality of turbulators are arranged along the blade height direction on the inner wall surface of the downstream passage, and the heat transfer coefficient between the inner wall surface and the cooling fluid is smaller in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the heat transfer coefficient is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the heat transfer coefficient is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0084] (7) In some embodiments, in any one of the configurations (1) to (6) above, The turbine blade is a plurality of turbulators provided on an inner wall surface of the downstream passage and arranged along the blade height direction; A pitch (PT) of the plurality of turbulators in the blade height direction is greater in the downstream region than in the upstream region.

[0085] According to the above configuration (7), a plurality of turbulators are arranged along the blade height direction on the inner wall surface of the downstream passage, and the pitch of the plurality of turbulators in the blade height direction is larger in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the pitch of the plurality of turbulators is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the pitch of the plurality of turbulators is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0086] (8) In some embodiments, in any of the configurations (1) to (7) above, The turbine blade is a plurality of turbulators provided on an inner wall surface of the downstream passage and arranged along the blade height direction; A height (e) of the turbulators relative to the inner wall surface of the downstream passage is smaller in the downstream region than in the upstream region.

[0087] According to the above configuration (8), a plurality of turbulators are arranged along the blade height direction on the inner wall surface of the downstream passage, and the height of the turbulators based on the inner wall surface is smaller in the downstream region than in the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be reduced compared to when the height of the turbulators is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be increased compared to when the height of the turbulators is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0088] (9) In some embodiments, in any of the configurations (1) to (8) above, The turbine blade is a plurality of turbulators provided on an inner wall surface of the downstream passage and arranged along the blade height direction; An angle (θ) between the direction of flow of the cooling fluid in the downstream passage and the extending direction of the turbulators is different between the downstream region and the upstream region.

[0089] According to the above configuration (9), a plurality of turbulators arranged along the blade height direction are provided on the inner wall surface of the downstream passage, and the angle between the flow direction of the cooling fluid in the downstream passage and the extending direction of the turbulators is different between the downstream region and the upstream region. Therefore, the amount of heat removed from the turbine blade by the cooling fluid in the downstream region can be made smaller than when the above angle is the same in the downstream region and the upstream region. Alternatively, the amount of heat removed from the turbine blade by the cooling fluid in the upstream region can be made larger than when the above angle is the same in the downstream region and the upstream region. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region for the blade body near the downstream passage.

[0090] (10) In some embodiments, in any one of the configurations (1) to (9) above, The turbine blade is a thermal barrier coating (86) covering a surface of the wing body; The thermal barrier coating has a thickness (T) less in the downstream region than in the upstream region.

[0091] According to the above configuration (10), the thickness of the thermal barrier coating covering the surface of the blade is smaller in the downstream region than in the upstream region. Therefore, the metal temperature of the blade can be made more uniform in the blade height direction than when the thermal barrier coating has the same thickness in the downstream region and the upstream region. Therefore, for the blade near the downstream passage, overcooling in the downstream region or insufficient cooling in the upstream region can be suppressed.

[0092] (11) In some embodiments, in any one of the configurations (1) to (10) above, the downstream passage is a cooling passage (60a) located closest to a leading edge or a cooling passage (60f) located closest to a trailing edge in a chord direction of the blade body, among the plurality of cooling passages; The position corresponding to the bypass portion in the blade height direction is located downstream of the bypass portion with respect to the flow of the cooling fluid in the downstream passage.

[0093] When the flow rate of the cooling fluid is large in the cooling passage located at the leading edge side or the trailing edge side, the direction of the cooling fluid flowing from the upstream passage through the bypass portion into the downstream passage is largely bent downstream, and the cooling fluid is supplied to a position downstream of the bypass portion in the downstream passage. In this regard, in the configuration of (11) above, the position where the value of the parameter indicating the characteristics of the multiple cooling holes, the multiple turbulators, or the thermal barrier coating is changed is provided downstream of the bypass portion. Therefore, even when the direction of the cooling fluid flowing into the downstream passage is largely bent downstream as described above, it is possible to make a difference in the amount of heat removed from the turbine blade by the cooling fluid, or the amount of heat input to the turbine blade from the gas flowing through the gas passage in which the turbine blade 40 is arranged, between the region upstream of the downstream position of the bypass portion (the position corresponding to the bypass portion) (the upstream region) and the downstream region (the downstream region). Therefore, it is possible to effectively suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage.

[0094] (12) A gas turbine (1) according to at least one embodiment of the present invention includes: A turbine blade (40) according to any one of (1) to (11) above; and a combustor (4) for generating combustion gas flowing through a combustion gas flow path in which the turbine blades are provided.

[0095] In the above configuration (12), the adjacent upstream passage and downstream passage are connected via the bypass section, so that a cooling fluid at a relatively low temperature before the temperature rises can be supplied to the downstream region of the downstream passage downstream of the bypass section, thereby effectively cooling the blade body in the vicinity of the downstream region. In the configuration of (12) above, the values ​​of parameters indicating the characteristics of the cooling holes, the turbulators, or the thermal barrier coating are different between the upstream region (upstream region) and the downstream region (downstream region) of the bypass section in the downstream passage. Therefore, it is possible to make a difference between the amount of heat removed from the turbine blade by the cooling fluid, or the amount of heat input to the turbine blade from the gas (combustion gas, etc.) flowing through the gas passage in which the turbine blade is arranged, between the upstream region and the downstream region in the downstream passage. Therefore, it is possible to suppress overcooling in the downstream region or insufficient cooling in the upstream region of the blade body near the downstream passage. That is, according to the above configuration (12), the provision of the bypass section makes it possible to effectively cool the turbine blades, and also makes it possible to suppress overcooling or insufficient cooling of the turbine blades that would otherwise be caused by the provision of the bypass section.

[0096] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and also includes modifications to the above-described embodiments and appropriate combinations of these modifications.

[0097] In this specification, expressions expressing relative or absolute configuration, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," do not only strictly represent such a configuration, but also represent a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained. For example, expressions indicating that things are in an equal state, such as "identical," "equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained. Furthermore, in this specification, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to shapes such as a rectangular shape or a cylindrical shape in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect can be obtained. In addition, in this specification, the expressions "comprise," "include," or "have" a certain element are not exclusive expressions that exclude the presence of other elements. [Explanation of symbols]

[0098] 1. Gas turbine 2. Compressor 4. Combustor 6. Turbine 8 Rotor 10 Compressor compartment 12 Air Intake 16 Stator blade 18 Moving blade 20 Casing 22 Turbine casing 24 Stator blade 26 Moving blade 28 Combustion gas passage 30 Exhaust chamber 32 Bulkhead 34 Turbulator 36 Bypass section 40 Turbine blade 42 Wing body 44 Leading Edge 46 Trailing edge 47 Trailing edge 48 Tip 49 Tabletop 50 proximal end 56 Pressure Surface 58 Suction surface 59 Folded part 60,60a~60f Cooling passage 61,61A,61B Serpentine flow passage 63 Inner Wall 64,64A,64B Exit opening 65 Upstream Passage 66 Downstream Passage 70 cooling holes 71 Inner wall surface 72 Cooling hole 80 Platform 82 Wing root 84A Internal flow path 84B Internal flow path 86 Thermal barrier coating PT Turbulator Pitch Ph Cooling hole pitch R1 Upstream region R2 downstream area T Thickness e Height θ angle (tilt angle)

Claims

1. The wing body and a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is a plurality of cooling holes formed on the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; Equipped with in the blade height direction, an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage have different values ​​of parameters indicating characteristics of the plurality of cooling holes, The opening density of the plurality of cooling holes is smaller in the downstream region than in the upstream region. Turbine blades.

2. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is a plurality of cooling holes formed on the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; Equipped with in the blade height direction, an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage have different values ​​of parameters indicating characteristics of the plurality of cooling holes, A pitch in the blade height direction between a pair of cooling holes adjacent to each other in the blade height direction is larger in the downstream region than in the upstream region. Turbine blades.

3. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is a plurality of cooling holes formed on the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; Equipped with in the blade height direction, an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage have different values ​​of parameters indicating characteristics of the plurality of cooling holes, The diameter of the cooling holes is smaller in the downstream region than in the upstream region. Turbine blades.

4. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is a plurality of cooling holes formed on the blade body so as to be arranged along the blade height direction, the cooling holes communicating with the downstream passage and opening on a surface of the blade body; Equipped with in the blade height direction, an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage have different values ​​of parameters indicating characteristics of the plurality of cooling holes, The surface roughness of the inner wall surfaces of the plurality of cooling holes is smaller in the downstream region than in the upstream region. Turbine blades.

5. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is A plurality of turbulators are provided on an inner wall surface of the downstream passage and arranged along the blade height direction. Equipped with in the blade height direction, values ​​of parameters indicating characteristics of the plurality of turbulators are different between an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage, The plurality of turbulators are provided so that a heat transfer coefficient between the cooling fluid and the inner wall surface of the downstream passage is smaller in the downstream region than in the upstream region. Turbine blades.

6. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is A plurality of turbulators are provided on an inner wall surface of the downstream passage and arranged along the blade height direction. Equipped with in the blade height direction, values ​​of parameters indicating characteristics of the plurality of turbulators are different between an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage, The pitch of the plurality of turbulators in the blade height direction is greater in the downstream region than in the upstream region. Turbine blades.

7. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is A plurality of turbulators are provided on an inner wall surface of the downstream passage and arranged along the blade height direction. Equipped with in the blade height direction, values ​​of parameters indicating characteristics of the plurality of turbulators are different between an upstream region located upstream of a position corresponding to the bypass portion in relation to the flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region in relation to the flow of the cooling fluid in the downstream passage, The height of the turbulator with respect to the inner wall surface of the downstream passage is smaller in the downstream region than in the upstream region. Turbine blades.

8. a plurality of turbulators provided on an inner wall surface of the downstream passage and arranged along the blade height direction; An angle between a flow direction of the cooling fluid in the downstream passage and an extension direction of the turbulators is different between the downstream region and the upstream region. A turbine blade according to any one of claims 1 to 7.

9. A wing body, a plurality of cooling passages each extending along a blade height direction inside the blade body and connected to each other via a turn-back portion; a bypass portion provided in a partition wall portion separating a pair of adjacent cooling passages among the plurality of cooling passages, the bypass portion connecting the pair of cooling passages to each other; Equipped with The pair of cooling passages includes an upstream passage and a downstream passage located downstream of the upstream passage with respect to the flow of the cooling fluid. A turbine blade, The turbine blade is A thermal barrier coating covering the surface of the wing body. Equipped with a value of a parameter indicating a characteristic of the thermal barrier coating is different between an upstream region located upstream of a position corresponding to the bypass portion in the blade height direction with respect to a flow of the cooling fluid in the downstream passage, and a downstream region located downstream of the upstream region with respect to the flow of the cooling fluid in the downstream passage, The thickness of the thermal barrier coating is less in the downstream region than in the upstream region. Turbine blades.

10. the downstream passage is a cooling passage located closest to a leading edge or a trailing edge in a chord direction of the blade body among the plurality of cooling passages, The position corresponding to the bypass portion in the blade height direction is located downstream of the bypass portion with respect to the flow of the cooling fluid in the downstream passage. A turbine blade according to any one of claims 1 to 7 or 9.

11. A turbine blade according to any one of claims 1 to 7 or 9; a combustor for generating combustion gas flowing through a combustion gas passage in which the turbine blades are provided.

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