TURBINE SHELL AND GAS TURBINE

Abstract

A turbine blade (40), comprising: a blade body (42), and a plurality of cooling passages (60), each of which extends within the blade body (42) along a blade height direction and which are connected to each other via return sections (58) arranged at an end section in the blade height direction to form a serpentine passage (61), the multitude of cooling cycles comprises (60): a most upstream passage (65) which is arranged on the most upstream side of a flow of a cooling fluid from the plurality of cooling passages (60), a most downstream passage (66) which is arranged on a most downstream side in the flow of the cooling fluid from the plurality of cooling passages (60), and at least one intermediate passage (67) arranged between the most upstream passage (65) and the most downstream passage (66) of the plurality of cooling passages (60), wherein the most upstream passage (65) is arranged at a position closest to a leading edge (44) in a chordal direction of the blade body (42) of the plurality of cooling passages (60) formed within the blade body (42) and extending along the vertical direction, wherein the turbine blade (40) has: a plurality of first turbulators (34) arranged on an inner wall surface (63) of the most upstream passage (65) and arranged along the blade height direction, a plurality of second turbulators (34) arranged on an inner wall surface of the at least one intermediate passage (67) and arranged along the blade height direction, and a plurality of third turbulators (34) arranged on an inner wall surface of the furthest downstream passage (66) and arranged along the blade height direction, wherein an average value of first angles (θa) of the plurality of first turbulators (34) is smaller than an average value of second angles (θb, θc or θd) of the plurality of second turbulators (34), wherein each of the first angles (θa) is a smallest angle between the first turbulator (34) and a flow direction of the cooling fluid in the most upstream passage (65), and each of the second angles (θb, θc or θd) is a smallest angle between the second turbulator (34) and a flow direction of the cooling fluid in the at least one intermediate passage (67), wherein the blade body (42) has a radially outer end (52) and a radially inner end (54) in the blade height direction and extends along the blade height direction within a region that includes a central area (R MEAN ) including a middle position (P c) of the blade body (42) in the blade height direction comprises an outer diameter-side area (R OD ) between the central area (R MEAN ) and the radially outer end (52) in the blade height direction and an inner diameter-side region (R ID ) between the central area (R MEAN ) and the radially inner end (54) in the blade height direction, and wherein a ratio P2 / e2 of a distance P2 between a pair of adjacent second turbulators (34) of the plurality of second turbulators (34) to a height e2 of the pair of second turbulators (34) with reference to the inner wall surface of the at least one intermediate passage [P 2 / e 2] OD < [P 2 / e 2] MEAN and [P 2 / e 2] OD < [P 2 / e 2] ID, (67) a relationship is fulfilled by: where [P2 / e2] OD the ratio in the outer diameter side area is, [P2 / e2] IDthe ratio in the inner diameter-side area is, and [P2 / e2] MEAN the relationship in the central area.

Description

TECHNICAL AREA

[0001] The present invention relates to a turbine blade and a gas turbine. BACKGROUND

[0002] In a turbine blade of a gas turbine or the like, it is known that the turbine blade, which is exposed to a hot gas flow, is cooled by a cooling fluid flowing through a cooling passage formed inside the turbine blade.

[0003] For example, patents 1 to 4 each comprise a turbine blade with an air foil section, inside which a meandering passage (serpentine passage) is formed through a plurality of cooling channels extending along the blade height direction. Rib-shaped turbulators are provided on the inner wall surfaces of the cooling channels of the turbine blade. The turbulators are designed to improve the heat transfer coefficient between the cooling fluid and the turbine blade by promoting turbulence in the flow of the cooling fluid within the cooling channels.

[0004] Furthermore, patent specification 4 describes that the inclination angle of the turbulators with respect to the flow direction of the cooling fluid in the cooling passages forming the serpentine passage is smaller in a downstream passage than in an upstream passage in order to suppress cooling of the turbine blade in the upstream passage, while improving cooling of the turbine blade in the downstream passage.

[0005] Patent specification 5 discloses a large, conical, air-cooled turbine blade with a serpentine flow cooling circuit, wherein a first leg is arranged adjacent to a leading edge of the blade and a third leg is arranged at the trailing edge, the third leg having an impact cooling channel formed along the upper span of the blade at the trailing edge. The impact cooling cavity includes impact openings connected to the third leg of the serpentine flow circuit to direct cooling air into the impact cavity, which is then discharged through outlet cooling openings spaced along the upper span of the trailing edge of the blade. A separate cooling channel is formed along the lower span of the trailing edge and includes outlet cooling openings to discharge cooling air through the lower span of the trailing edge. The upper impact cavity is supplied with separate cooling air from the lower impact cavity.The blade is formed from cores, with the trailing edge section of the blade consisting of a first core element, which forms the last leg of the serpentine flow circuit and the upper span baffle cavity, and a second core element, which forms the lower cooling circuit. The first core element includes a core connection with a nozzle opening into which a nozzle on the second core is inserted to form a core assembly used to create the trailing edge cooling circuit.

[0006] Patent specification 6 discloses a cooling air supply system for effectively cooling a blade of a gas turbine using air, and in particular a system that makes it possible to cool a rotating blade (moving blade) with air when a rotor is cooled with steam. Citation list for patent literature Patent specification 1: JP H11-229806 A Patent specification 2: JP 2004-137958 A Patent specification 3: JP 2015-214979 A Patent specification 4: JP 2019-85973A Patent specification 5: US 7,572,102 B1 Patent specification 6: DE 698 31 109 T2 SUMMARY

[0007] A turbine blade with turbulators in the serpentine section can become locally overcooled, depending on its position within the turbine. If excessive cooling occurs within the turbine blade, the efficiency of the cooling air application can decrease, and the overall turbine efficiency may also decline.

[0008] In view of the foregoing, an object of at least one embodiment of the present invention is to provide a turbine blade and a gas turbine which makes it possible to cool the turbine blade effectively while suppressing excessive cooling of the turbine blade.

[0009] The present invention provides a turbine blade according to independent claims 1 and 2, and a gas turbine according to independent claim 9. Advantageous modifications are found in dependent claims 3 to 8.

[0010] At least one embodiment of the present invention provides a turbine blade and a gas turbine, making it possible to effectively cool the turbine blade while suppressing excessive cooling of the turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic configuration diagram of a gas turbine according to an exemplary embodiment. Fig. Figure 2 is a schematic partial cross-sectional view of a guide vane (turbine blade) along the blade height direction according to an exemplary embodiment. Fig. Figure 3 is a schematic cross-sectional view along line AA in Fig. 2. Fig. Figure 4 is a schematic cross-sectional view of a guide vane (turbine blade) according to an exemplary embodiment. Fig. Figure 5 is a schematic cross-sectional view of a guide vane (turbine blade) according to an exemplary embodiment. Fig. Figure 6 is a schematic cross-sectional view of a guide vane (turbine blade) according to an exemplary embodiment. Fig. Figure 7 is a schematic cross-sectional view of a guide vane (turbine blade) according to an exemplary embodiment. Fig. Figure 8 is a schematic cross-sectional view of a rotor blade (turbine blade) according to an exemplary embodiment. Fig. Figure 9 is a schematic partial cross-sectional view of a guide vane (turbine blade) along the blade height direction according to an exemplary embodiment. Fig. Figure 10 is a schematic diagram to describe a configuration of turbulators according to an exemplary embodiment. Fig. Figure 11 is a schematic diagram to describe a configuration of turbulators according to an exemplary embodiment. DETAILED DESCRIPTION

[0011] Exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, it is intended that dimensions, materials, shapes, relative positions, and the like of components described in the exemplary embodiments are to be interpreted merely as illustrative and are not intended to limit the scope of the present invention unless specifically indicated otherwise. (Gas turbine configuration)

[0012] First, a gas turbine is described to which a turbine blade is applied according to some exemplary embodiments. Fig. Figure 1 is a schematic configuration diagram of a gas turbine to which a turbine blade is applied according to an exemplary embodiment. As in Fig. As shown in Figure 1, the gas turbine 1 comprises a compressor 2 for generating compressed air, a combustion chamber 4 for generating fuel gas from the compressed air and fuel, and a turbine 6 configured to be driven by the fuel gas. In the case of the gas turbine 1 being used for power generation, a generator (not shown) is connected to the turbine 6.

[0013] The compressor 2 comprises a plurality of guide vanes 16, which are fixed to a compressor housing 10, and a plurality of rotor blades 18, which are mounted on a rotor 8 in an alternating pattern with the guide vanes 16. Intake air from an air inlet 12 is sent to the compressor 2. The air passes through the plurality of guide vanes 16 and the plurality of rotor blades 18 and is compressed into compressed air at high temperature and high pressure.

[0014] Combustion chamber 4 is supplied with fuel and the compressed air produced by compressor 2. In combustion chamber 4, the fuel and compressed air are mixed and burned to produce the fuel gas, which serves as the working fluid for turbine 6. As described in Fig. As shown in Figure 1, a plurality of combustion chambers 4 can be arranged along the circumferential direction around the rotor in the housing 20.

[0015] The turbine 6 has a fuel gas passage 28 formed in a turbine housing 22 and comprises a plurality of guide vanes 24 and a plurality of rotor blades 26 arranged in the fuel gas passage 28. The guide vanes 24 are fixed to the turbine housing 22, and a set of guide vanes 24 arranged along the circumferential direction of the rotor 8 forms a guide vane row. The rotor blades 26 are also mounted on the rotor 8, and a set of rotor blades 26 arranged along the circumferential direction of the rotor 8 forms a rotor blade row. The guide vane rows and the rotor blade rows are arranged alternately in the axial direction of the rotor 8.

[0016] In the turbine 6, the rotor 8 is driven to rotate as the fuel gas, introduced from the combustion chamber 4 into the fuel gas passage 28, passes through the plurality of guide vanes 24 and the plurality of rotor blades 26. This drives the generator connected to the rotor 8 to produce energy. The fuel gas that has driven the turbine 6 is expelled to the outside via an exhaust chamber 30.

[0017] In some embodiments, at least one of the rotor blade 26 or the guide vane 24 of the turbine 6 is a turbine blade 40 as described below. In the following, the guide vane 24 is mainly described as the turbine blade 40 with reference to the drawings, but in principle the same description can be applied to the rotor blade 26 as the turbine blade 40. (Configuration of turbine blade)

[0018] Fig. Figure 2 is a schematic partial cross-sectional view of the guide vane 24 (turbine blade 40) along the blade height direction according to an exemplary embodiment. Fig. Figure 3 is a schematic cross-sectional view along line AA in Fig. 2. The arrows in the figure indicate the flow direction of the cooling fluid. The “radial direction”, “axial direction”, and “circumferential direction” in the figures refer, respectively, to the radial, axial, and circumferential directions of the turbine rotor when the turbine blade 40 is installed in the turbine 6.

[0019] As in Fig. 2 and Fig. As shown in Figure 3, the guide vane 24 (turbine blade 40) according to one embodiment comprises a blade body 42, a leading edge plate 86, and a trailing edge plate 88, which are connected to both end sections of the blade body 42 in the blade height direction. Here, the blade height direction of the turbine blade 40 (i.e., the blade height direction of the blade body 42) corresponds to the radial direction of the turbine rotor on which the turbine blade 40 is installed. When the guide vane 24 is installed in the turbine 6, the leading edge plate 86 is arranged radially inward with respect to the blade body 42, and the trailing edge plate 88 is arranged radially outward with respect to the blade body 42.

[0020] The base plate 88 is separated from the turbine housing 22 (see Fig. 1) supported, and the guide vane 24 is supported by the turbine casing 22 via the base plate 88. The blade body 42 has a radially outer end 52 on the side of the base plate 88 (i.e., on the radially outer side) and a radially inner end 54 on the side of the top plate 86 (i.e., on the radially inner side).

[0021] The blade body 42 of the guide vane 24 has a leading edge 44 and a trailing edge 46 extending from the radially outer end 52 to the radially inner end 54. The blade surface of the blade body 42 comprises a positive pressure surface 56 and a negative pressure surface 58, which extend along the blade height direction between the radially outer end 52 and the radially inner end 54.

[0022] The blade body 42 has a cooling flow path through which a cooling fluid (e.g., air) flows to cool the turbine blade 40. In the Fig. 2 and Fig. In the exemplary embodiment shown in Figure 3, the blade body 42 has a serpentine passage 61 including a plurality of cooling passages 60 as the cooling flow path.

[0023] In the turbine blade 40, the serpentine passage 61 comprises a plurality of cooling passages 60a, 60b, 60c, ... (hereinafter also referred to collectively as "cooling passage 60"), each of which extends along the blade height direction. Inside the blade body 42 of the turbine blade 40, a plurality of ribs 32 are arranged along the blade height direction. Each adjacent cooling passage 60 is divided by one of the ribs 32.

[0024] In the Fig. 2 and Fig. In the exemplary embodiment shown in Figure 3, the serpentine passage 61 comprises five cooling passages 60a to 60e. The cooling passages 60a to 60e are arranged in this order from the front edge 44 to the rear edge 46.

[0025] Two adjacent cooling passages (e.g., cooling passage 60a and cooling passage 60b) of the plurality of cooling passages 60 that form the serpentine passage 61 are connected via a return section 58, which is arranged at an end section (an end section on the side of the radially outer end 52 or an end section on the side of the radially inner end 54) in the blade height direction. A return passage is formed at this return section 58, through which the flow direction of the cooling fluid returns in the blade height direction. Thus, the serpentine passage 61 has a serpentine shape in the radial direction as a whole. That is, the plurality of cooling passages 60 communicate with each other to form the serpentine passage 61.

[0026] The plurality of cooling passages 60 that form the serpentine passage 61 comprises an upstream passage 65, which is located on the upstream side in the flow of the cooling fluid, a downstream passage 66, which is located on the downstream side in the flow of the cooling fluid, and an intermediate passage 67, which is arranged between the upstream passage 65 and the downstream passage 66 of the plurality of cooling passages 60. In the Fig. 2 and Fig. In the exemplary embodiments shown in Figure 3, of the plurality of cooling passages 60, the cooling passage 60a closest to the leading edge 44 is the passage 65 furthest upstream, the cooling passage 60e closest to the trailing edge 46 is the passage 66 furthest downstream, and the cooling passages 60b, 60c and 60d between the cooling passage 60a and the cooling passage 60e are the intermediate passages 67.

[0027] In the Fig. 2 and Fig. In the three exemplary embodiments shown, the most upstream passage 65 (i.e., cooling passage 60a), which forms the serpentine passage 61, is the passage that is closest to the leading edge 44 in the chordal direction of the blade body 42 of the plurality of cooling passages formed inside the blade body 42 and extends along the vertical direction. In other words, there are no other cooling passages extending along the blade vertical direction in a position between the leading edge 44 and the serpentine passage 61 in the chordal direction.

[0028] In the turbine blade 40 with the serpentine passage 61 described above, the cooling fluid is introduced into the serpentine passage 61 via an internal passage 89 formed inside the base plate 88 and an inlet opening 62 formed at the radially outer end 52 of the blade body 42, and the cooling fluid flows sequentially downwards through the plurality of cooling passages 60.The cooling fluid, flowing through the most downstream passage 66 (the one furthest downstream of the multiple cooling passages 60 in the direction of flow), then flows to the fuel gas passage 28 outside the guide vane 24 (turbine blade 40) via an outlet opening 64 formed at the radially inner end 54 (on the side of the tip plate 86) of the blade body 42 and an internal passage 87 formed inside the tip plate 86, or is expelled into the fuel gas through cooling holes 70 in the trailing edge section, as described below. By supplying the cooling fluid to the serpentine passage 61, the blade body 42, located in the fuel gas passage 28 of the turbine 6 and exposed to the hot fuel gas, is cooled.

[0029] In some embodiments, such as in Fig. 2 and Fig. As shown in Figure 3, the trailing edge section (section including the trailing edge 46) of the blade body 42 has a plurality of cooling holes 70 arranged along the blade height direction. The plurality of cooling holes 70 communicate with the cooling passage (in the illustrated example, the most downstream passage 66 of the serpentine passage 61), which is formed inside the blade body 42 and opens to the surface in the trailing edge section 47 of the blade body 42.

[0030] The cooling fluid flowing through the cooling passage (in the illustrated example, the most downstream passage 66 of the serpentine passage 61) partially passes through the cooling holes 70 and flows to the fuel gas passage 28 outside the turbine blade 40 through the openings in the trailing edge section of the blade body 42. Thus, the trailing edge section 47 of the blade body 42 is convectively cooled when the cooling fluid flows through the cooling holes 70.

[0031] Rib-shaped turbulators 34 are arranged on at least some of the inner wall surfaces 63 of the multiple cooling passages 60. In the Fig. 2 and Fig. In the exemplary embodiment shown in Figure 3, a plurality of turbulators 34 are arranged on each of the inner wall surfaces 63 of the plurality of cooling passages 60.

[0032] Here are Fig. 10 and Fig. 11 each a schematic diagram to describe a configuration of the turbulators 34 according to an exemplary embodiment. Fig. Figure 10 is a schematic partial cross-sectional view along a plane including the blade height direction and the blade thickness direction (the circumferential direction of the rotor 8) of the Fig. 2 and Fig. 3 turbine blades shown 40. Fig. Figure 11 is a schematic partial cross-sectional view along a plane including the blade height direction and the blade width direction (the axial direction of the rotor 8) of the in Fig. 2 and Fig. 3 turbine blades shown 40.

[0033] As in Fig. As shown in Figure 10, each turbulator 34 is arranged on the inner wall surface 63 of the cooling passage 60, and “e” indicates the height of the turbulator 34 from the inner wall surface 63. Furthermore, as shown in Fig. 10 and Fig. Figure 11 shows the plurality of turbulators 34 in the cooling passage 60 arranged at intervals of a distance P. It also shows how in Fig. 11 shows, θ the acute angle (hereinafter also referred to as the “angle of inclination”) between the flow direction (arrow LF in Fig. 11) of the cooling fluid in the cooling passage 60 and each turbulator 34. In other words, the acute angle formed between the direction of extension of the cooling passage 60 (along the blade height direction) and the direction of extension of each turbulator 34 at the inner wall surface 36 of the cooling passage 60 is the inclination angle θ of the turbulator 34.

[0034] The turbulator 34 in the cooling passage 60 promotes flow turbulence, such as a vortex in the vicinity of the turbulator 34, as the cooling fluid flows through the cooling passage 60. Specifically, the cooling fluid flowing through the turbulator 34 forms a vortex between the turbulator 34 and its downstream neighbor. Consequently, the vortex of the cooling fluid adheres to the inner wall surface 63 of the cooling passage 60 in the vicinity of the midpoint between the turbulators 34 adjacent in the flow direction of the cooling fluid, thereby increasing the heat transfer coefficient between the cooling fluid and the blade body 42. As a result, it is possible to cool the turbine blade 40 effectively.

[0035] The appearance of a cooling fluid vortex varies with the inclination angle θ of the turbulator 34, which affects the heat transfer coefficient between the cooling fluid and the inner wall surface 63 of the blade body 42. Furthermore, if the height e of the turbulator 34 is too high relative to the distance P between the turbulators 34, the vortex cannot adhere to the inner wall surface 63. Therefore, suitable relationships exist between the heat transfer coefficient and the inclination angle θ of the turbulator 34, and between the heat transfer coefficient and the ratio of the distance P to the height e.

[0036] The turbine blade 40 is described in more detail below according to some exemplary embodiments. Fig. Figures 4 to 7 are each a schematic cross-sectional view of the guide vane 24 (turbine blade 40) according to an exemplary embodiment. Fig. Figure 8 is a schematic cross-sectional view of the rotor blade 26 (turbine blade 40) according to an exemplary embodiment. The arrows in the figures indicate the flow direction of the cooling fluid.

[0037] Before the features of the turbulators 34 of the turbine blade 40 are described according to some exemplary embodiments, the configuration of the turbine blade 40 according to in Fig. Examples shown in sections 4 to 8 are described.

[0038] The in Fig. Guide vane 24 (turbine blade 40) shown in figures 4 to 7 has essentially the same configuration as the one in Fig. 2 and Fig. 3 guide vane 24 shown. However, the serpentine passage 61 formed in the turbine blade 40 consists in the Fig. Figure 6 shows an exemplary embodiment consisting of three cooling passages 60a, 60b and 60e. Of these, the cooling section 60a closest to the leading edge 44 is the most upstream passage 65, the cooling passage 60e closest to the trailing edge 46 is the most downstream passage 66, and the cooling passage 60b between the most upstream passage 65 and the most downstream passage 66 is the intermediate passage 67.

[0039] The in Fig. The rotor blade 26 (turbine blade 40) shown in Figure 8 comprises a blade body 42 and a platform 80. The blade body 42 is arranged to extend along the blade height direction (or the radial direction of the rotor 8) and has a base end (radially inner end) 50, which is fixed to the platform 80 and arranged on the radially inner side, and a tip end (radially outer end) 48, which is arranged on the side opposite the base end 50 in the blade height direction and forms the tip of the blade body 42.

[0040] The blade body 42 of the rotor blade 26 has essentially the same configuration as that with reference to Fig. 2 and Fig. 3 describes the guide vane body 42 of the guide vane 24. In particular, the guide vane body 42 of the rotor blade 26 has a leading edge 44 and a trailing edge 46 extending from the tip end 48 to the base end 50. The blade surface of the guide vane body 42 comprises a positive pressure surface 56 and a negative pressure surface 58, which extend along the blade height direction between the tip end 48 and the base end 50. Inside the guide vane body 42 of the rotor blade 26, a serpentine passage 61 is formed, which consists of a plurality of cooling passages 60. In the section described in Fig. In the exemplary embodiment shown in Figure 8, the serpentine passage 61 consists of five cooling passages 60a to 60e.

[0041] In the Fig. In the rotor blade 26 (turbine blade 40) shown in Figure 8, the cooling fluid is introduced into the serpentine passage 61 via an internal passage (not shown) formed inside the platform 80 and an inlet opening 62 formed at the base end 50 of the blade body 42, and the cooling fluid flows downwards sequentially through the plurality of cooling passages 60. Then, the cooling fluid flowing through the most downstream passage 66, which is located furthest downstream of the plurality of cooling passages 60 in the direction of flow of the cooling fluid, flows to the combustion gas passage 28 outside the rotor blade 26 (turbine blade 40) via an outlet opening 64 formed at the tip end 48 of the blade body 42, or it is expelled in the combustion gas through cooling holes 70 in the trailing edge section.

[0042] In the rotor blade 26, the turbulators 34 described above are arranged on at least some of the inner wall surfaces of the plurality of cooling passages 60. In the Fig. In the exemplary embodiment shown in Figure 8, the plurality of turbulators 34 are arranged on each of the inner wall surfaces of the plurality of cooling passages 60.

[0043] The features of the turbulators 34 of the turbine blade 40 according to some embodiments are described below with reference to Fig. 4 to 8 described.

[0044] In the Fig. In the turbine blades 40 shown in Figures 4 to 8, θa, θb, θc, θd, and θe are the inclination angles of the turbulators 34 in the cooling passages 60a to 60e, Pa, Pb, Pc, Pd, and Pe are the distances between adjacent turbulators 34 in the respective passages, i.e., the cooling passages 60a to 60e, and ea, eb, ec, ed, and ee are the heights (or average heights) of the adjacent turbulators 34 in the respective passages. Fig. In the exemplary embodiment shown in Figures 4 to 8, the inclination angles of the plurality of turbulators 34 on the inner wall surface 63 correspond to each other in each cooling cycle 60 (60a to 60e).

[0045] In the Fig. 4, Fig. 5 and Fig. The guide vane 24 shown in Figure 7 satisfies the inclination angles of the turbulators 34 in the cooling passages 60a to 60e θa<θb=θc=θd and θe<θb=θc=θd. Furthermore, θa=θe. In the Fig. 4 and Fig. In the guide vane 24 shown in section 5, θb=θc=θd=90° applies. In the Fig. For guide vane 24 shown in section 7, θb=θc=θd<90° applies.

[0046] In the Fig. The guide vanes 24 shown in Figure 6 satisfy the inclination angles of the turbulators 34 in the cooling passages 60a, 60b and 60c θa<θb and θe<θb. In the Fig. For guide vane 24 shown in Figure 6, θb = 90°. Furthermore, θa = θe.

[0047] In the Fig. The rotor blade 26 shown in Figure 8 has the following inclination angles of the turbulators 34 in the cooling passages 60a to 60e: θa < θb = θc = θd and θe < θb = θc = θd. Furthermore, θa = θe. In the Fig. 8 shown rotor blade 26, θb=θc=θd=90° applies.

[0048] In some embodiments, the average value of the inclination angles (first angles) of the plurality of turbulators 34 (first turbulators) arranged in the most upstream passage 65 is smaller than the average value of the inclination angles (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, the average value of the inclination angles θa (first angles) of the plurality of turbulators 34 arranged in the cooling passage 60a, which represents the most upstream passage 65, is smaller than the average value of the inclination angles θb, θc, or θd (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c, or 60d, which represent the intermediate passages 67. Here, the "average value" indicates an arithmetic mean.

[0049] In some embodiments, each of the inclination angles (first angles) of the plurality of turbulators 34 (first turbulators) arranged in the most upstream passage 65 is smaller than each of the inclination angles (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, each of the inclination angles θa (first angles) of the plurality of turbulators 34 arranged in the cooling passage 60a, which is the most upstream passage 65, is smaller than each of the inclination angles θb, θc or θd (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c or 60d, which represent the intermediate passages 67.

[0050] Since, according to the embodiments described above, the first angle (θa), which is the inclination angle of the first turbulators arranged in the most upstream passage 65 (cooling passage 60a), is relatively small, the heat transfer coefficient between the cooling fluid and the blade body 42 in the most upstream passage 65 can be relatively increased, and the leading edge section (where the most upstream passage 65 is located) of the blade body 42, which has a high cooling load, can be cooled effectively.Furthermore, since, according to the embodiments described above, the second angle (θb, θc, or θd), which is the inclination angle of the second turbulators arranged in the intermediate passage 67 (cooling passage 60b, 60c, or 60d) forming the serpentine passage 61, is relatively large, the heat transfer coefficient between the cooling fluid and the blade body 42 in the intermediate passage 67 can be relatively reduced, and excessive cooling of the turbine blade 40, which tends to occur in the intermediate section (where the intermediate passage 67 is located) of the blade body 42 depending on the installation position of the turbine blade 40 (e.g., installation position in the axial direction), can be suppressed. Since, as described above, the heat transfer coefficient in the intermediate passage 67 is also relatively small, the temperature rise of the cooling fluid in the intermediate passage 67 can be suppressed.Thus, air whose temperature has not risen significantly can be supplied to the furthest downstream passage 66 (cooling passage 60e), and the blade body 42 can be effectively cooled. Therefore, according to the embodiments described above, it is possible to effectively cool the turbine blade 40 while suppressing excessive cooling.

[0051] In some embodiments, the average value of the inclination angles (third angles) of the plurality of turbulators 34 (third turbulators) arranged in the most downstream passage 66 is smaller than the average value of the inclination angles (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, an average value of the inclination angles θe (third angles) of the plurality of turbulators 34 arranged in the cooling passage 60e, which is the most downstream passage 66, is smaller than an average value of the inclination angles θb, θc or θd (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c or 60d, which is the intermediate passage 67.

[0052] In some embodiments, each of the inclination angles (third angles) of the plurality of turbulators 34 (third turbulators) arranged in the most downstream passage 66 is smaller than each of the inclination angles (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, each of the inclination angles θe (third angles) of the plurality of turbulators 34 arranged in the cooling passage 60e, which is the most downstream passage 66, is smaller than each of the inclination angles θb, θc or θd (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c or 60d, which is the intermediate passage 67.

[0053] Since, according to the embodiments described above, the third angle (θe), which is the inclination angle of the third turbulators arranged in the most downstream passage 66 forming the serpentine passage 61, is smaller than the second angle (θb, θc, or θd), the heat transfer coefficient between the cooling fluid and the blade body 42 in the most downstream passage 66 can be relatively increased. Thus, cooling of the turbine blade 40 in the downstream region of the serpentine passage 61 can be improved, where a relatively hot cooling fluid, which has passed through the most upstream passage 65 and the intermediate passage 67, is supplied. Consequently, it is possible to cool the turbine blade 40 more effectively, while more effectively suppressing excessive cooling.

[0054] In some embodiments, the average value of the second angles is not less than 85° and not greater than 90°. In one embodiment, each of the second angles is not less than 85° and not greater than 90°.

[0055] In the region where the inclination angle of the turbulators 34 is approximately 90°, the heat transfer coefficient between the cooling fluid and the turbine blade tends to increase as the inclination angle decreases. In this respect, according to the embodiments described above, since the second angle (θb, θc, or θd) of the second turbulators in the intermediate passage 67 is not less than 85° and not greater than 90°, the heat transfer coefficient in the intermediate passage 67 can be effectively suppressed. Consequently, it is possible to effectively suppress excessive cooling of the turbine blade 40.

[0056] In some embodiments, the absolute value of the difference between the average value of the first angles and the average value of the third angles is not less than 0° and not greater than 5°. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, the absolute value (e.g., |θa-θb|, |θa-θc|, or |θa-θd|) of the difference between the average value of the inclination angles θa (first angles) of the plurality of turbulators 34 arranged in the cooling passage 60a, which is the most upstream passage 65, and the average value of the inclination angles θb, θc, or θd (second angles) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c, or 60d, which represent the intermediate passages 67, shall be not less than 0° and not greater than 5°.

[0057] In some embodiments, each of the absolute values ​​of the differences between the first angles of the plurality of first turbulators and the third angles of the plurality of third turbulators is not less than 0° and not greater than 5°. For example, in the Fig. In the exemplary embodiments shown in Figures 4 to 8, an absolute value (e.g., |θa-θb|, |θa-θc|, or |θa-θd|) of the difference between a specific angle of inclination θa (first angle) of the plurality of turbulators 34 arranged in the cooling passage 60a, which is the most upstream passage 65, and a specific angle of inclination θb, θc, or θd (second angle) of the plurality of turbulators 34 (second turbulators) arranged in the cooling passage 60b, 60c, or 60d, which represent the intermediate passages 67, shall be not less than 0° and not greater than 5°.

[0058] In some embodiments, an average value of the inclination angles (first angles) of the plurality of turbulators 34 arranged in the most upstream passage 65 and an average value of the inclination angles (third angles) of the plurality of turbulators 34 arranged in the most downstream passage 66 may be not less than 50° and not greater than 70° or not less than 55° and not greater than 65°.

[0059] In some embodiments, each of the inclination angles (first angles) of the plurality of turbulators 34 arranged in the most upstream passage 65 and each of the inclination angles (third angles) of the plurality of turbulators 34 arranged in the most downstream passage 66 may be not less than 50° and not greater than 70° or not less than 55° and not greater than 65°.

[0060] In some embodiments, the difference between the average value of the second angles and the average value of the first angles is not less than 15° and not greater than 45°.

[0061] Since, according to the embodiments described above, the difference between the average value of the second angles (θb, θc, or θd) and the average value of the first angles (θa) is not less than 15° and not greater than 45°, the difference between the heat transfer coefficient in the most upstream passage 65, where the first turbulators are located, and the heat transfer coefficient in the intermediate passage 67, where the second turbulators are located, can be somewhat increased. Consequently, the leading-edge section (where the most upstream passage 65 is located) of the blade body 42, which has a high cooling load, can be effectively cooled, while excessive cooling in the intermediate section (where the intermediate passage 67 is located) of the blade body 42 is suppressed.Furthermore, the temperature rise of the cooling fluid supplied to the furthest downstream passage 66 can be suppressed. Therefore, according to the embodiments described above, it is possible to effectively cool the turbine blade 40 while effectively suppressing excessive cooling.

[0062] In some embodiments, the difference between the average value of the second angles and the average value of the third angles is not less than 15° and not greater than 45°.

[0063] Since, according to the embodiments described above, the difference between the average value of the second angles (θb, θc, or θd) and the average value of the third angles (θe) is not less than 15° and not greater than 45°, the difference between the heat transfer coefficient in the furthest downstream passage 66, where the third turbulators are located, and the heat transfer coefficient in the intermediate passage 67, where the second turbulators are located, can be somewhat increased. Consequently, the temperature rise of the cooling fluid flowing through the intermediate passage 67 can be suppressed, while the heat transfer between the cooling fluid and the blade body 42 in the furthest downstream passage 66 can be simplified.Consequently, it is possible to improve the cooling of the turbine blade 40 in the downstream area of ​​the serpentine passage 61, while effectively suppressing excessive cooling of the turbine blade 40.

[0064] In some embodiments, a ratio P2 / e2 of a distance P2 between a pair of adjacent turbulators 34 of the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67, to a height e2 of the adjacent turbulators 34 satisfies a relationship of: [P2 / e2] OD <[P2 / e2] MEAN and [P2 / e2] OD <[P2 / e2] ID , where [P2 / e2] OD the ratio in an outer diameter-side area R OD is, [P2 / e2] ID the ratio in an inner diameter-side area R ID is, and [P2 / e2] MEAN the relationship in a central area R MEAN is. Here is the central area R MEANa region including a central position Pc of the blade body 42 in the blade height direction, the outer diameter-side region R OD is an area between the central area R MEAN and the radially outer end 52 (or the tip end 48) in the blade height direction, and the inner diameter-side area R ID is an area between the central area R MEAN and the radially inner end 54 (or the base end 50) in the blade height direction (see Fig. 5). The central area R MEAN , the outer diameter-side area R OD and the inner diameter-side area R ID Each of the three equal parts of the extension area of ​​the blade body 42 in the blade height direction can be one of three equal parts.

[0065] In some embodiments, an average value of the ratios [P2 / e2] is used for the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. OD in the outer diameter-side area R OD less than an average value of the ratios [P2 / e2] MEAN in the central area R MEAN , and an average value of the ratios [P2 / e2] OD in the outer diameter-side area R OD is smaller than an average value of the ratios [P2 / e2] ID in the inner diameter-side area R ID .

[0066] In some embodiments, for the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67, each of the ratios [P2 / e2] OD in the outer diameter-side area R OD smaller than any of the ratios [P2 / e2] MEAN in the central area R MEAN, and each of the ratios [P2 / e2] OD in the outer diameter-side area R OD is smaller than any of the ratios [P2 / e2] ID in the inner diameter-side area R ID .

[0067] In some embodiments, such as in Fig. Figure 5 shows the distance P2 in the outer diameter-side region R for the plurality of turbulators 34 (second turbulators) arranged in the intermediate passage 67. OD smaller than the distance P2 in the central area R MEAN , and the distance P2 in the outer diameter-side area R OD is smaller than the distance P2 in the inner diameter-side area R ID .

[0068] Within a specific range of distance P and height e of the turbulators 34, the heat transfer coefficient between the cooling fluid and the blade body 42 tends to increase as the ratio P / e of distance P to height e decreases. Furthermore, the temperature distribution of the fuel gas in the fuel gas passage 28, where the turbine blade 40 is located, can be higher in the radially outer region, depending on the installation position of the turbine blade 40 (e.g., its axial orientation). In this respect, according to the embodiments described above, the ratio P2 / e2 of distance P2 to height e2 of the second turbulators in the intermediate passage 67 in the outer diameter-side region R OD is smaller than in the central area R MEAN and the inner diameter-side area R IDIn the blade height direction, the cooling effect of the turbine blade 40 can be achieved in the outer diameter-side area R. OD can be improved. Consequently, it is possible to effectively cool the turbine blade 40, so that the temperature of the turbine blade 40 in the outer diameter-side region R OD does not become excessively high where the fuel gas temperature, as described above, is relatively high.

[0069] In some embodiments, a ratio [P1 / e1] MEAN a distance P1 between a pair of adjacent turbulators 34 (first turbulators) of the plurality of turbulators 34 (first turbulators) arranged in the most upstream passage 65, to a height e1 of the pair of turbulators 34 (first turbulators) with reference to the inner wall surface 63 of the most upstream passage 65 in the central region R MEAN , and a ratio [P2 / e2] MEANa distance P2 between a pair of adjacent turbulators 34 (secondary turbulators) of the plurality of turbulators 34 (secondary turbulators) arranged in the intermediate passage 67, to a height e2 of the pair of turbulators 34 (secondary turbulators) with reference to the inner wall surface 63 of the intermediate passage 67 in the central area R MEAN a relationship of: [P1 / e1] MEAN < [P2 / e2] MEAN .

[0070] In some embodiments, an average value of the ratios [P1 / e1] is used. MEAN in the central area R MEAN for the multitude of turbulators 34 (first turbulators) arranged in the most upstream passage 65, smaller than an average value of the ratios [P2 / e2] MEAN in the central area R MEAN for the multitude of turbulators 34 (second turbulators) that are arranged in the intermediate passage 67.

[0071] In some embodiments, each of the ratios [P1 / e1] MEAN in the central area R MEAN for the plurality of turbulators 34 (first turbulators) arranged in the most upstream passage 65, smaller than any of the ratios [P2 / e2] MEAN in the central area R MEAN for the multitude of turbulators 34 (second turbulators) that are arranged in the intermediate passage 67.

[0072] According to the embodiments described above, in the central area R MEAN in the blade height direction the ratio [P1 / e1] MEAN a distance P1 to a height e1 of the first turbulators in the most upstream passage 65 smaller than the ratio [P2 / e2] MEAN a distance P2 to a height e2 of the second turbulators in the intermediate passage 67. Consequently, in the central area R MEANThe leading edge section (where the most upstream passage 65 is located) of the blade body 42, which has a high cooling load, can be effectively cooled, while excessive cooling in the intermediate section (where the intermediate passage 67 is located) of the blade body 42 can be suppressed. Furthermore, the temperature rise of the cooling fluid supplied to the most downstream passage 66 can be suppressed. Consequently, it is possible to effectively cool the turbine blade 40 while effectively suppressing excessive cooling.

[0073] In some embodiments, a ratio [P3 / e3] MEANa distance P3 between a pair of adjacent turbulators 34 (third turbulators) of the plurality of turbulators 34 (third turbulators) arranged in the most downstream passage 66, to a height e3 of the pair of turbulators 34 (third turbulators) with respect to the inner wall surface 63 of the most downstream passage 66 in the central region R MEAN , and a ratio [P2 / e2] MEAN a distance P2 between a pair of adjacent turbulators 34 (secondary turbulators) of the plurality of turbulators 34 (secondary turbulators) arranged in the intermediate passage 67, to a height e2 of the pair of turbulators 34 (secondary turbulators) with reference to the inner wall surface 63 of the intermediate passage 67 in the central area R MEAN a relationship of: [P3 / e3] MEAN < [P2 / e2] MEAN .

[0074] In some embodiments, an average value of the ratios [P3 / e3] is used. MEAN in the central area R MEAN for the multitude of turbulators 34 (third turbulators) arranged in the furthest downstream passage 66, smaller than an average value of the ratios [P2 / e2] MEAN in the central area R MEAN for the multitude of turbulators 34 (second turbulators) that are arranged in the intermediate passage 67.

[0075] In some embodiments, each of the ratios [P3 / e3] MEAN in the central area R MEAN for the plurality of turbulators 34 (third turbulators) arranged in the furthest downstream passage 66, smaller than any of the ratios [P2 / e2] MEAN in the central area R MEAN for the multitude of turbulators 34 (second turbulators) that are arranged in the intermediate passage 67.

[0076] According to the embodiments described above, in the central area R MEAN in the blade height direction the ratio [P3 / e3] MEAN a distance P3 to a height e3 of the third turbulators in the furthest downstream passage 66 smaller than the ratio [P2 / e2] MEAN a distance P2 to a height e2 of the second turbulators in the intermediate passage 67.

[0077] Therefore, in the central area R MEAN The heat transfer coefficient between the cooling fluid and the blade body 42 is relatively increased in the most downstream passage 66. This improves the cooling of the turbine blade 40 in the downstream region of the serpentine passage 61, where relatively hot cooling fluid, which has passed through the most upstream passage 65 and the intermediate passage 67, is supplied.

[0078] Fig. Figure 9 is a schematic partial cross-sectional view of the guide vane 24 (turbine blade 40) according to an exemplary embodiment along the blade height direction. The in Fig. The guide vane 24 shown in Figure 9 has essentially the same configuration as the one in Figure 9. Fig. 2 guide vanes shown 24 on.

[0079] In some embodiments, the guide vane 24 (turbine blade 40) comprises, e.g., as in Fig. Figure 9 shows a sealing tube 90 that penetrates the blade body 42 such that it extends along the blade height direction and is arranged such that it passes through any one of the at least one intermediate passage 67. In the Fig. In the exemplary embodiment shown in Figure 9, the sealing tube 90 is arranged to pass through the base plate 88 and the head plate 86 of the guide vane 24 and through the cooling passage 60b (intermediate passage 67).

[0080] The sealing tube 90 has an inlet opening 92 at one end and an outlet opening 94 at the other end. Sealing fluid is supplied to the sealing tube 90 through the inlet opening 92, and the sealing fluid, having flowed through the path formed in the sealing tube 90, is discharged through the outlet opening 94 into a cavity 85, which is formed radially inward with respect to the base plate 86. This prevents the combustion gas from being drawn into the cavity 85 from the combustion gas passage 28. The sealing tube 90 can be supplied with fluid (e.g., air) from the same supply source as the cooling fluid.

[0081] The thickness (measured perpendicular to the chord direction) of the blade body 42 with the air foil shape is relatively small in the leading and trailing edge sections and relatively large in the intermediate section between the leading and trailing edge sections in the chord direction. In this respect, according to the embodiment described above, the intermediate passage 67 (cooling passage 60 in the intermediate section 60), where the flow path region can be easily secured, is used to provide the sealing tube 90, which runs through the cooling passage 60 (intermediate passage 67), with the turbulators 34. A sealing fluid can be supplied to the turbine blade 40 through the sealing tube 90.

[0082] The contents described in the preceding examples would be understood, for example, as follows. (1) A turbine blade (40) according to at least one embodiment comprises: a blade body (42); and a plurality of cooling passages (60), each of which extends within the blade body along a blade height direction and which are connected to each other via return sections (58) arranged at an end section in the blade height direction to form a serpentine passage (61).The plurality of cooling passages comprises: an upstream passage (65) located on the upstream side of the plurality of cooling passages in the flow of a cooling fluid; a downstream passage (66) located on the downstream side of the plurality of cooling passages in the flow of the cooling fluid; and at least one intermediate passage (67) located between the upstream passage and the downstream passage of the plurality of cooling passages. The upstream passage is located at a position closest to a leading edge (44) in a chordal direction of the blade body of the plurality of cooling passages formed within the blade body and extending along the vertical direction.The turbine blade comprises: a plurality of first turbulators (34) arranged on an inner wall surface (63) of the most upstream passage and arranged along the blade height direction; a plurality of second turbulators (34) arranged on an inner wall surface of the at least one intermediate passage and arranged along the blade height direction; and a plurality of third turbulators (34) arranged on an inner wall surface of the most downstream passage and arranged along the blade height direction.An average value of first angles (θa) of the plurality of first turbulators with respect to a flow direction of the cooling fluid in the most upstream passage is smaller than an average value of second angles (θb, θc or θd) of the plurality of second turbulators with respect to a flow direction of the cooling fluid in the at least one intermediate passage.

[0083] The angle (θ) formed by the flow direction of the cooling fluid in the cooling passage and each turbulator on the inner wall surface of the cooling passage is also referred to below as the inclination angle of the turbulator.

[0084] Since with the above configuration (1) the first angle, which is the inclination angle of the first turbulators arranged in the most upstream passage, is relatively small, the heat transfer coefficient between the cooling fluid and the blade body in the most upstream passage can be relatively increased, and the leading edge section (where the most upstream passage is located) of the blade body, which has a high cooling load, can be cooled effectively.Additionally, with the above configuration (1), since the second angle, which is the inclination angle of the second turbulators arranged in the intermediate passage forming the serpentine section, is relatively large, the heat transfer coefficient between the cooling fluid and the blade body in the intermediate passage can be relatively reduced, and excessive cooling of the turbine blade, which tends to occur in the intermediate section (where the intermediate passage is located) of the blade body depending on the installation position of the turbine blade or the like, can be suppressed. Furthermore, since, as described above, the heat transfer coefficient in the intermediate passage is relatively small, the temperature rise of the cooling fluid in the intermediate passage can be suppressed.Thus, air whose temperature has not risen significantly can be supplied to the most downstream passage, and the blade body can be effectively cooled. Therefore, with the above configuration (1), it is possible to effectively cool the turbine blade while suppressing excessive cooling.

[0085] (2) In some embodiments according to the above configuration (1), an average value of third angles (θe) of the plurality of third turbulators with respect to a flow direction of the cooling fluid in the most downstream passage is smaller than the average value of the second angles.

[0086] Since, with the above configuration (2), the third angle, which is the inclination angle of the third turbulators arranged in the most downstream passage forming the serpentine section, is smaller than the second angle, the heat transfer coefficient between the cooling fluid and the blade body in the most downstream passage can be relatively increased. Thus, cooling of the turbine blade in the downstream region of the serpentine section can be improved, where relatively hot cooling fluid, having passed through the most upstream passage and the intermediate passage, is supplied. Consequently, it is possible to cool the turbine blade more effectively while more effectively suppressing excessive cooling.

[0087] (3) In some embodiments according to the above configuration (2), an absolute value of a difference between the average value of the first angles and the average value of the third angles shall be not less than 0 degrees and not greater than 5 degrees.

[0088] Since, with the above configuration (3), the first angle of the plurality of first turbulators in the most upstream passage is almost equal to the third angle of the third turbulators in the most downstream passage, the turbine blade is relatively easy to manufacture.

[0089] (4) In some embodiments according to any of the above configurations (1) to (3), each of the second angles is not less than 85 degrees and not greater than 90 degrees.

[0090] In the region where the inclination angle of the turbulators is approximately 90°, the heat transfer coefficient between the cooling fluid and the turbine blade tends to increase as the inclination angle decreases. Since, with the configuration (4) described above, the second angle of the second turbulators in the intermediate pass is not less than 85° and not greater than 90°, the heat transfer coefficient in the intermediate pass can be effectively suppressed. Consequently, it is possible to effectively prevent excessive cooling of the turbine blade.

[0091] (5) In some embodiments according to one of the above configurations (1) to (4), the difference between the average value of the second angles and the average value of the first angles shall be not less than 15 degrees and not greater than 45 degrees.

[0092] Since, with the above configuration (5), the difference between the average value of the second angles and the average value of the first angles is not less than 15° and not greater than 45°, the difference between the heat transfer coefficient in the most upstream passage, where the first turbulators are located, and the heat transfer coefficient in the intermediate passage, where the second turbulators are located, can be somewhat increased. Consequently, the leading-edge section (where the most upstream passage is located) of the blade body, which has a high cooling load, can be effectively cooled, while excessive cooling in the intermediate section (where the intermediate passage is located) of the blade body can be suppressed. Furthermore, the temperature rise of the cooling fluid supplied to the most downstream passage can be suppressed.Therefore, with the above configuration (5) it is possible to effectively cool the turbine blade while effectively suppressing excessive cooling.

[0093] (6) In some embodiments according to any of the above configurations (1) to (5), the turbine blade comprises a sealing tube (90) which passes through the blade body in such a way that it extends along the blade height direction and is arranged so that it passes through any of the at least one intermediate passage.

[0094] The thickness of the blade body with the air foil shape is relatively small in the leading and trailing edge sections and relatively large in the intermediate section between the leading and trailing edge sections. In this respect, with the above configuration (6), the intermediate passage (cooling passage in the intermediate section), where the flow path region can be easily secured, is used to provide the sealing tube with the turbulators running through the cooling passage (intermediate passage). Sealing fluid can be supplied to the turbine blade through the sealing tube.

[0095] (7) In some embodiments according to one of the preceding configurations (1) to (6), the blade body has a radially outer end (52) and a radially inner end (54) in the blade height direction and extends along the blade height direction within a region comprising a central area (R MEAN) including a mean position (Pc) of the blade body in the blade height direction, comprising an outer diameter-side region (R) OD ) between the central area and the radially outer end in the blade height direction and an inner diameter-side area (R ID ) between the central region and the radially inner end in the blade height direction. A ratio P2 / e2 of a distance P2 between a pair of adjacent second turbulators of the plurality of second turbulators to a height e2 of the pair of second turbulators with respect to the inner wall surface of the at least one intermediate passage satisfies a relationship of: [P2 / e2] OD < [P2 / e2] MEAN and [P2 / e2] OD < [P2 / e2] ID , where [P2 / e2] OD the ratio in the outer diameter side area is, [P2 / e2] ID the ratio in the inner diameter-side area is, and [P2 / e2] MEANthe relationship in the central area.

[0096] In a specific region with a distance P and height e of the turbulators, the heat transfer coefficient between the cooling fluid and the blade body tends to increase as the ratio P / e of the distance P to the height e decreases. Furthermore, the temperature distribution of the fuel gas in the fuel gas passage where the turbine blade is located can be higher in the radially outer region, depending on the blade's installation position. Since, with the configuration described above (7), the ratio P2 / e2 of a distance P2 to a height e2 of the second turbulators in the intermediate passage is smaller in the outer diameter-side region than in the central region and the inner diameter-side region in the blade height direction, the cooling effect of the turbine blade can be improved in the outer diameter-side region.Consequently, it is possible to effectively cool the turbine blade so that the temperature of the turbine blade in the outer diameter side area does not become excessively high, where the fuel gas temperature is relatively high as described above.

[0097] (8) In some embodiments according to one of the preceding configurations (1) to (7), the blade body has a radially outer end and a radially inner end in the blade height direction and extends along the blade height direction within a region comprising a central region including a mean position of the blade body in the blade height direction, an outer diameter-side region between the central region and the radially outer end in the blade height direction, and an inner diameter-side region between the central region and the radially inner end in the blade height direction. A ratio [P1 / e1] MEANa distance P1 between a pair of adjacent first turbulators of the plurality of first turbulators to a height e1 of the pair of first turbulators with reference to the inner wall surface of the most upstream passage in the central region, and a ratio [P2 / e2] MEAN a distance P2 between a pair of adjacent second turbulators of the plurality of second turbulators to a height e2 of the pair of second turbulators with reference to the inner wall surface of the at least one intermediate passage in the central region satisfy a relationship of: [P1 / e1] MEAN < [P2 / e2] MEAN .

[0098] With the above configuration (8) the ratio [P1 / e1] in the central area in the blade height direction is MEAN a distance P1 to a height e1 of the first turbulators in the most upstream passage is smaller than the ratio [P2 / e2] MEANa distance P2 to a height e2 of the second turbulators in the intermediate passage. Consequently, in the central region, the leading-edge section (where the most upstream passage is located) of the blade body, which has a high cooling load, can be effectively cooled, while excessive cooling in the intermediate section (where the intermediate passage is located) of the blade body can be suppressed. Furthermore, the temperature rise of the cooling fluid supplied to the most downstream passage can be suppressed. Therefore, with the above configuration (8), it is possible to effectively cool the turbine blade while effectively suppressing excessive cooling.

[0099] (9) In some embodiments according to the above configuration (8) the ratio [P2 / e2] MEAN and a ratio [P3 / e3] MEANa distance P3 between a pair of adjacent third turbulators of the plurality of third turbulators to a height e3 of the pair of third turbulators with reference to the inner wall surface of the most downstream passage in the central region a relationship of: [P3 / e3] MEAN < [P2 / e2] MEAN .

[0100] With the above configuration (9) the ratio [P3 / e3] in the central area in the blade height direction is MEAN a distance P3 to a height e3 of the third turbulators in the furthest downstream passage is smaller than the ratio [P2 / e2] MEANa distance P2 to a height e2 of the second turbulators in the intermediate passage. Consequently, in the central region, the heat transfer coefficient between the cooling fluid and the blade body can be relatively increased in the most downstream passage. Thus, cooling of the turbine blade can be improved in the downstream region of the serpentine passage, where a relatively hot cooling fluid, which has passed through the most upstream passage and the intermediate passage, is supplied.

[0101] (10) A gas turbine (1) according to at least one embodiment comprises: a turbine (6) with the turbine blade (40) according to one of the points (1) to (9) described above; and a combustion chamber (4) for generating a fuel gas which flows through a fuel gas passage (48) in which the turbine blade is arranged.

[0102] Since with the above configuration (10) the first angle, which is the inclination angle of the first turbulators arranged in the most upstream passage, is relatively small, the heat transfer coefficient between the cooling fluid and the blade body in the most upstream passage can be relatively increased, and the leading edge section (where the most upstream passage is located) of the blade body, which has a high cooling load, can be cooled effectively.Furthermore, since with the above configuration (10) the second angle, which is the inclination angle of the second turbulators arranged in the intermediate passage forming the serpentine section, is relatively large, the heat transfer coefficient between the cooling fluid and the blade body in the intermediate passage can be relatively reduced, and excessive cooling of the turbine blade, which tends to occur in the intermediate section (where the intermediate passage is located) of the blade body depending on the installation position of the turbine blade or the like, can be suppressed. Moreover, since, as described above, the heat transfer coefficient in the intermediate passage is relatively small, the temperature rise of the cooling fluid in the intermediate passage can be suppressed.Thus, air whose temperature has not risen significantly can be supplied to the most downstream passage, and the blade body can be effectively cooled. Therefore, with the above configuration (10), it is possible to effectively cool the turbine blade while suppressing excessive cooling.

[0103] Furthermore, in the present description, an expression of relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" is not to be interpreted as indicating only the arrangement in a strictly literal sense, but also as encompassing a state in which the arrangement is shifted relative to a tolerance or by an angle or a distance, making it possible to achieve the same function.

[0104] For example, an expression for an identical state such as "the same", "equal" and "uniform" should not be understood as indicating only the state in which the feature is strictly identical, but also a state in which there is a tolerance or difference with which the same function can still be achieved.

[0105] Furthermore, the term "shape," such as a rectangular or cylindrical shape, should not be understood as referring only to the geometrically strict shape, but also to a shape with irregularities or chamfered corners within the area in which the same effect can be achieved.

[0106] On the other hand, expressions such as "exhibit", "comprise" and "have" should not be understood as excluding other components.

Claims

[1] A turbine blade (40) comprising: a blade body (42), and a plurality of cooling passages (60), each of which extends within the blade body (42) along a blade height direction and which are connected to each other via return sections (58) arranged at an end section in the blade height direction to form a serpentine passage (61), the multitude of cooling cycles comprises (60): a most upstream passage (65) which is arranged on the most upstream side of a flow of a cooling fluid from the plurality of cooling passages (60), a most downstream passage (66) which is arranged on a most downstream side in the flow of the cooling fluid from the plurality of cooling passages (60), and at least one intermediate passage (67) arranged between the most upstream passage (65) and the most downstream passage (66) of the plurality of cooling passages (60), wherein the most upstream passage (65) is arranged at a position closest to a leading edge (44) in a chordal direction of the blade body (42) of the plurality of cooling passages (60) formed within the blade body (42) and extending along the vertical direction, wherein the turbine blade (40) has: a plurality of first turbulators (34) arranged on an inner wall surface (63) of the most upstream passage (65) and arranged along the blade height direction, a plurality of second turbulators (34) arranged on an inner wall surface of the at least one intermediate passage (67) and arranged along the blade height direction, and a plurality of third turbulators (34) arranged on an inner wall surface of the furthest downstream passage (66) and arranged along the blade height direction, wherein an average value of first angles (θa) of the plurality of first turbulators (34) is smaller than an average value of second angles (θb, θc or θd) of the plurality of second turbulators (34), wherein each of the first angles (θa) is a smallest angle between the first turbulator (34) and a flow direction of the cooling fluid in the most upstream passage (65), and each of the second angles (θb, θc or θd) is a smallest angle between the second turbulator (34) and a flow direction of the cooling fluid in the at least one intermediate passage (67), wherein the blade body (42) has a radially outer end (52) and a radially inner end (54) in the blade height direction and extends along the blade height direction within a region that includes a central area (R MEAN ) including a middle position (P c) of the blade body (42) in the blade height direction comprises an outer diameter-side area (R OD ) between the central area (R MEAN ) and the radially outer end (52) in the blade height direction and an inner diameter-side region (R ID ) between the central area (R MEAN ) and the radially inner end (54) in the blade height direction, and wherein a ratio P2 / e2 of a distance P2 between a pair of adjacent second turbulators (34) of the plurality of second turbulators (34) to a height e2 of the pair of second turbulators (34) with reference to the inner wall surface of the at least one intermediate passage [P2 / e2]OD<[P2 / e2]MEAN and [P2 / e2]OD<[P2 / e2]ID, (67) a relationship is fulfilled by: where [P2 / e2] OD the ratio in the outer diameter side area is, [P2 / e2] ID the ratio in the inner diameter-side area is, and [P2 / e2]MEAN the relationship in the central area. [2] A turbine blade (40) comprising: a blade body (42), and a plurality of cooling passages (60), each of which extends within the blade body (42) along a blade height direction and which are connected to each other via return sections (58) arranged at an end section in the blade height direction to form a serpentine passage (61), the multitude of cooling cycles comprises (60): a most upstream passage (65) which is arranged on the most upstream side of a flow of a cooling fluid from the plurality of cooling passages (60), a most downstream passage (66) which is arranged on a most downstream side in the flow of the cooling fluid from the plurality of cooling passages (60), and three intermediate passages (67) arranged between the most upstream passage (65) and the most downstream passage (66) of the plurality of cooling passages (60), wherein the most upstream passage (65) is arranged at a position closest to a leading edge (44) in a chordal direction of the blade body (42) of the plurality of cooling passages (60) formed within the blade body (42) and extending along the vertical direction, wherein the turbine blade (40) has: a plurality of first turbulators (34) arranged on an inner wall surface (63) of the most upstream passage (65) and arranged along the blade height direction, a plurality of second turbulators (34) arranged on an inner wall surface of each of the three intermediate passages (67) and arranged along the blade height direction, and a plurality of third turbulators (34) arranged on an inner wall surface of the furthest downstream passage (66) and arranged along the blade height direction, wherein an average value of first angles (θa) of the plurality of first turbulators (34) is smaller than an average value of second angles (θb, θc or θd) of the plurality of second turbulators (34), wherein each of the first angles (θa) is a smallest angle between the first turbulator (34) and a flow direction of the cooling fluid in the most upstream passage (65), and each of the second angles (θb, θc or θd) is a smallest angle between the second turbulator (34) and a flow direction of the cooling fluid in each of the three intermediate passages (67), and wherein an average value of third angles (θe) of the plurality of third turbulators (34) is smaller than the average value of the second angles (θb, θc or θd), wherein each of the third angles (θe) is a smallest angle between the third turbulator (34) and a flow direction of the cooling fluid in the most downstream passage (66). [3] The turbine blade (40) according to claim 2, wherein an absolute value of a difference between the average value of the first angles (θa) and the average value of the third angles (θe) is not less than 0 degrees and not greater than 5 degrees. [4] The turbine blade (40) according to any one of claims 1 to 3, wherein each of the second angles (θb, θc or θd) is not less than 85 degrees and not greater than 90 degrees. [5] The turbine blade (40) according to any one of claims 1 to 4, wherein the difference between the average value of the second angles (θb, θc or θd) and the average value of the first angles (θa) is not less than 15 degrees and not greater than 45 degrees. [6] The turbine blade (40) according to any one of claims 1 to 5, comprising a sealing tube (90) which passes through the blade body (42) in such a way that it extends along the blade height direction and is arranged in such a way that it passes through any one of the at least one intermediate passage (67). [7] The turbine blade (40) according to any one of claims 1 to 6, wherein the blade body (42) has a radially outer end (52) and a radially inner end (54) in the blade height direction and extends along the blade height direction within a region that includes a central area (R MEAN ) including a middle position (P c ) of the blade body (42) in the blade height direction comprises an outer diameter-side area (R OD ) between the central area (R MEAN ) and the radially outer end (52) in the blade height direction and an inner diameter-side region (R ID) between the central area (R MEAN ) and the radially inner end (54) in the blade height direction, and where a ratio [P1 / e1] MEAN a distance P1 between a pair of adjacent first turbulators (34) of the plurality of first turbulators (34) to a height e1 of the pair of first turbulators (34) with reference to the inner wall surface of the most upstream passage (65) in the central region (R MEAN ), and a ratio [P2 / e2] MEAN a distance P2 between a pair of adjacent second turbulators (34) of the plurality of second turbulators (34) to a height e2 of the pair of second turbulators (34) with reference to the inner wall surface of the at least one intermediate passage (67) in the central region (R MEAN ) fulfill a relationship of: [P1 / e1]MEAN<[P2 / e2]MEAN. [8] The turbine blade (40) according to claim 7, wherein the ratio [P2 / e2] MEANand a ratio [P3 / e3] MEAN a distance P3 between a pair of adjacent third turbulators (34) of the plurality of third turbulators (34) to a height e3 of the pair of third turbulators (34) with reference to the inner wall surface of the most downstream passage (66) in the central region (R MEAN ) fulfill a relationship of: [P3 / e3]MEAN<[P2 / e2]MEAN. [9] A gas turbine (1) comprising: a turbine (6) with the turbine blade (40) according to one of claims 1 to 8, and a combustion chamber (4) for generating a fuel gas which flows through a fuel gas passage (48) in which the turbine blade (40) is arranged.

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