Turbine blade and gas turbine

Abstract

turbine rotor blade (26), comprising a leading edge section (46) with a plurality of cooling holes (48), which has a multitude of cooling holes (48): m cooling holes (48) arranged in a first region (S1) in a rotor blade height direction, where m is an integer of 2 or more; and n cooling holes (48) arranged in a second region (S2) on a blade tip side of the first region (S1) in the blade height direction, where n is an integer of 2 or more, and where n / b < m / a is satisfied, where a is a dimension of the first region (S1) in the blade height direction and b is a dimension of the second region (S2) in the blade height direction, which has a multitude of cooling holes (48): a plurality of cooling hole rows (48A, 48B, 48C), each of which is arranged along the blade height direction in the first area (S1); and at least one cooling hole row (48D, 48E), each of which is arranged along the blade height direction in the second area (S2), and where the number of cooling hole rows (48D, 48E) in the second area (S2) is less than the number of cooling hole rows (48A, 48B, 48C) in the first area (S1), where the number of cooling hole rows (48A, 48B, 48C) in the first area (S1) is 3, and where the number of cooling hole rows (48D, 48E) in the second area (S2) is 2, wherein the plurality of cooling hole rows (48A, 48B, 48C) in the first region (S1) comprises a pressure-side cooling hole row (48A) formed on a pressure surface, a suction-side cooling hole row (48B) formed on a suction surface, and a middle cooling hole row (48C) formed between the pressure-side cooling hole row (48A) and the suction-side cooling hole row (48B), and wherein the at least one cooling hole row (48D, 48E) in the second area (S2) has a pressure-side cooling hole row (48D) formed on the pressure surface and a suction-side cooling hole row (48E) formed on the suction surface, characterized in that The pressure-side cooling hole row (48A) in the first area (S1) is arranged along a first virtual line (V1) which is linear, wherein the suction-side cooling hole row (48B) in the first area (S1) is arranged along a second virtual line (V2) which is linear, wherein the middle cooling hole row (48C) is arranged along a third virtual line (V3) which is linear, and whereupon X is defined as a distance between the first virtual line (V1) and the second virtual line (V2) at the same position in the blade height direction on the blade surface (50), Y is defined as a distance between the second virtual line (V2) and the third virtual line (V3) at the same position in the blade height direction on the blade surface (50), Ymax is defined as a maximum value of the distance Y in the first region (S1), and h1 is defined as a position in the blade height direction such that the distance X is smaller than the distance Ymax, the second area (S2) is located between the position h1 and the blade tip (56), wherein the turbine rotor blade (26) further comprises: a profile section (36) containing the leading edge section (46), a hub surface (54) which is connected to the blade surface (50) of the profile section (36) via a rounding section (58), where the lower end of the first area (S1) is the upper end of the rounding section (58) in the direction of the blade height.

Description

TECHNICAL AREA

[0001] The present disclosure relates to a turbine rotor blade and a cooling structure of a gas turbine. BACKGROUND

[0002] Since a turbine blade of a gas turbine is exposed to hot gas, the blade surface is film-cooled by the injection of cooling air through numerous cooling holes formed in the leading edge section. In addition to the film cooling effect, the cooling hole also cools the leading edge section through its inner surface (heat sink effect).

[0003] JP 5 536 001 B2, for example, discloses a turbine rotor blade with a leading edge section having three rows of cooling holes arranged linearly along the rotor blade height direction.

[0004] The publications EP 3 333 366 A1 and EP 3 098 385 A1 represent further state of the art. PRESENTATION OF THE INVENTION Problems to be solved

[0005] In a typical turbine rotor blade, the radius of curvature of the blade surface decreases at the leading edge towards the blade tip (tip side). In this case, if the leading edge section has a large number of cooling holes arranged along the blade's vertical direction, as in the turbine rotor blade of JP 5 536 001 B2, the distance between adjacent cooling holes tends to decrease towards the blade tip. In such a case, the blade tip side is more likely to be cooled than the blade root side (hub side). Consequently, if a sufficient amount of cooling air is supplied to the cooling holes on the blade root side, an excessive amount of cooling air will be supplied to the cooling holes on the blade tip side.

[0006] In view of the above, an objective of at least one embodiment of the present invention is to provide a turbine rotor blade and a gas turbine, wherein it is possible to cool the leading edge section with a small amount of cooling air. Problem solving

[0007] The present invention is defined by the turbine rotor blade according to the features of independent claim 1. The dependent claims describe preferred embodiments.

[0008] (1) A turbine rotor blade according to at least one embodiment of the present invention has a leading-edge section with a plurality of cooling holes. The plurality of cooling holes comprises: m cooling holes arranged in a first region in a rotor blade height direction, wherein m is an integer of 2 or more; and n cooling holes arranged in a second region on a rotor blade tip side of the first region in the rotor blade height direction, wherein n is an integer of 2 or more, and wherein n / b < m / a is satisfied, where a is a dimension of the first region in the rotor blade height direction and b is a dimension of the second region in the rotor blade height direction.

[0009] With the turbine rotor blade described above in (1), since n / b < m / a is satisfied, it is possible to prevent an excessive amount of cooling air from being supplied to the cooling holes in the second region. Thus, the amount of cooling air supplied to the cooling holes in the first region and the amount of cooling air supplied to the cooling holes in the second region can be optimized, and the leading edge section can be effectively cooled with a small amount of cooling air.

[0010] (2) In some embodiments of the above configuration (1), the radius of curvature of a blade surface of the leading edge section decreases in a cross-section perpendicular to the blade height direction in the direction of a blade tip.

[0011] If the radius of curvature of the blade surface of the leading edge section decreases in a cross-section perpendicular to the blade height direction towards the blade tip, the distance between adjacent cooling holes in the leading edge section decreases towards the blade tip. Therefore, if n / b equals m / a, the blade tip side is more likely to be cooled than the blade root side.

[0012] In this respect, the turbine rotor blade described above in (2), since n / b < m / a is satisfied, prevents an excessive amount of cooling air from being supplied to the cooling holes in the second region. Thus, the amount of cooling air supplied to the cooling holes in the first region and the amount of cooling air supplied to the cooling holes in the second region can be optimized, and the leading edge section can be effectively cooled with a small amount of cooling air.

[0013] (3) In some embodiments of the above configuration (1), the second area is located between a position at half the height of the rotor blade and the rotor blade tip.

[0014] With the turbine rotor blade described above in (3), the amount of cooling air supplied to the cooling holes in an area near the rotor blade tip, where the amount of cooling air supplied tends to be too high, can be reduced, and the leading edge section can be effectively cooled with a small amount of cooling air.

[0015] (4) In some embodiments of the above configuration (3), the second region extends from a position at two-thirds of the rotor blade height to the rotor blade tip.

[0016] With the turbine rotor blade described above in (4), the amount of cooling air supplied to the cooling holes in the area near the rotor blade tip, where the amount of cooling air supplied tends to be too high, can be reduced, and the leading edge section can be effectively cooled with a small amount of cooling air.

[0017] (5) In some embodiments of one of the turbine rotor blades described above in (1) to (4), the plurality of cooling holes comprises: a plurality of cooling hole rows, each of which is arranged along the rotor blade height direction in the first region; and at least one cooling hole row, each of which is arranged along the rotor blade height direction in the second region. The number of cooling hole rows in the second region is less than the number of cooling hole rows in the first region.

[0018] If the radius of curvature of the blade surface of the leading edge section decreases in a cross-section perpendicular to the blade height direction towards the blade tip, the distance between adjacent cooling hole rows in the leading edge section decreases towards the blade tip. Therefore, if the number of cooling hole rows in the first region is equal to the number of cooling hole rows in the second region, the blade tip side is more likely to be cooled than the blade root side.

[0019] In this respect, the turbine rotor blade described above in (5) prevents an excessive amount of cooling air from being supplied to the cooling hole row(s) in the second area, since the number of cooling hole rows in the second area is lower than the number of cooling hole rows in the first area. Thus, the amount of cooling air supplied to the cooling holes in the first area and the amount supplied to the cooling holes in the second area can be optimized, and the leading edge section can be effectively cooled with a small amount of cooling air.

[0020] (6) In some embodiments of the above configuration (5) the number of cooling hole rows in the first area is 3, and the number of cooling hole rows in the second area is 2.

[0021] With the turbine rotor blade described above in (6), it is possible, in contrast to the case where the number of cooling hole rows in the first area and the number of cooling hole rows in the second area are both 3, to prevent an excessive amount of cooling air being supplied to the cooling hole rows in the second area. Thus, the leading edge section can be effectively cooled with a small amount of cooling air.

[0022] (7) In some embodiments of the above configuration (6), the plurality of cooling hole rows in the first region includes a pressure-side cooling hole row formed on a pressure surface, a suction-side cooling hole row formed on a suction surface, and a middle cooling hole row formed between the pressure-side and suction-side cooling hole rows. The at least one cooling hole row in the second region includes a pressure-side cooling hole row formed on the pressure surface and a suction-side cooling hole row formed on the suction surface.

[0023] With the turbine rotor blade described above in (7), the leading edge section exposed to the hot gas can be effectively cooled from the pressure surface to the suction surface with a small amount of cooling air.

[0024] (8) In some embodiments of the above configuration (7), the pressure-side cooling hole row in the first region is arranged along a first virtual line which is linear, the suction-side cooling hole row in the first region is arranged along a second virtual line which is linear, the middle cooling hole row is arranged along a third virtual line which is linear, and where X is defined as a distance between the first virtual line and the second virtual line at the same position in the blade height direction on the blade surface, Y is defined as a distance between the second virtual line and the third virtual line at the same position in the blade height direction on the blade surface, Ymax is defined as a maximum value of the distance Y in the first region, and h1 is defined as a position in the blade height direction such that the distance X is less than the distance Ymax,The second area is located between position h1 and the blade tip.

[0025] With the turbine blade described above in (8), the spacing between the cooling hole rows in the second region can be smaller than the spacing Ymax, even if the number of cooling hole rows in the second region is less than the number of cooling hole rows in the first region, since the second region is located between position h1 and the blade tip. This prevents the cooling air volume supplied to the cooling hole rows in the second region from being insufficient. Thus, the cooling air volume supplied to the cooling holes in the first region and the cooling air volume supplied to the cooling holes in the second region can be optimized, and the leading edge section can be effectively cooled with a small cooling air volume.

[0026] (9) In some embodiments of the turbine rotor blade described above in (7) or (8), each of the cooling holes of the pressure-side cooling hole row extends in the first region along a direction parallel to a first straight line intersecting the pressure surface, each of the cooling holes of the suction-side cooling hole row extends in the first region along a direction parallel to a second straight line intersecting the suction surface, each of the cooling holes of the pressure-side cooling hole row extends in the second region along a direction parallel to a third straight line intersecting the pressure surface, each of the cooling holes of the suction-side cooling hole row extends in the second region along a direction parallel to a fourth straight line intersecting the suction surface, and an angle between the third straight line and the fourth straight line is smaller than an angle between the first straight line and the second straight line.

[0027] With the turbine rotor blade described above in (9), the leading edge section exposed to the hot gas can be effectively cooled from the pressure surface to the suction surface with a small amount of cooling air.

[0028] (10) A gas turbine according to at least one embodiment of the present invention comprises: a compressor for generating compressed air; a combustion chamber for generating combustion gas using the compressed air and fuel; and a turbine configured to be driven by the combustion gas, and the turbine comprising the turbine blade described in any one of points (1) to (9) above.

[0029] With the gas turbine described above in (10), the amount of cooling air supplied to the cooling holes in the first area and the amount of cooling air supplied to the cooling holes in the second area can be optimized, and the leading edge section can be effectively cooled with a small amount of cooling air. Therefore, damage to the turbine blade can be reduced with a small amount of cooling air, allowing the gas turbine to operate stably. Beneficial effects

[0030] At least one embodiment of the present invention provides a turbine rotor blade and a gas turbine, wherein it is possible to cool the leading edge section with a small amount of cooling air. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic configuration diagram of a gas turbine 1 according to an embodiment. Fig. Figure 2 is a schematic configuration diagram of a turbine rotor blade 26 according to one embodiment. Fig. 3 is a partial view of a cross-section of the in Fig. 2 turbine rotor blade 26 shown in a first area S1, perpendicular to the rotor blade height direction. Fig. 4 is a partial view of a cross-section of the in Fig. 2 turbine rotor blade 26 shown in a second area S2, perpendicular to the rotor blade height direction. Fig. Figure 5 is a diagram showing a relationship between the blade height direction position h and the distance X, Y, where X is a distance on the blade surface 50 between the first virtual line V1 and the second virtual line V2, which is in Fig. 2 or Fig. 3 are shown, is defined at the same position in the blade height direction, and Y is defined as a distance on the blade surface 50 between the second virtual line V2 and the third virtual line V3 at the same position in the blade height direction. Fig. Figure 6 is a schematic configuration diagram of a turbine rotor blade 26 according to one embodiment. Fig. 7 is a partial view of a cross-section of the in Fig. 6 turbine rotor blade 26 shown in a second area S2, perpendicular to the rotor blade height direction. Fig. Figure 8 is a diagram showing a relationship between the blade height direction position h and the distance X, Y, Z, where X is a distance on the blade surface 50 between the first virtual line V1 and the second virtual line V2, which is in Fig. 3, Fig. 6 or Fig. 7 are shown, defined at the same position in the blade height direction, Y is defined as a distance on the blade surface 50 between the second virtual line V2 and the third virtual line V3 at the same position in the blade height direction, and Z is defined as a distance on the blade surface 50 between the fourth virtual line V4 and the fifth virtual line V5 at the same position in the blade height direction. Fig. Figure 9 is a diagram showing another example of the arrangement of the cooling holes 48 of the leading edge section 46. Fig. Figure 10 is a diagram showing another example of the arrangement of the cooling holes 48 of the leading edge section 46. DETAILED DESCRIPTION

[0031] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, unless specifically indicated, it is intended that dimensions, materials, shapes, relative positions, and the like of components described in the embodiments are to be interpreted as illustrative only, and it is not intended to limit the scope of the present invention.

[0032] For example, an expression for a relative or absolute arrangement such as "in a direction", "along a direction", "parallel", "orthogonal", "centered", "concentric" and "coaxial" is not to be interpreted as only indicating the arrangement in a strictly literal sense, but also encompassing a state in which the arrangement is shifted relative by a tolerance or by an angle or a distance, making it possible to achieve the same function.

[0033] For example, an expression of an equal state such as "equal" and "uniform" is not to be interpreted as indicating only the state in which the feature is strictly the same, but also includes a state with a tolerance or difference that can still achieve the same function.

[0034] Furthermore, the expression of a shape such as a rectangular shape or a cylindrical shape is not only to be understood as the geometrically strict shape, but also includes a shape with irregularities or chamfered corners within the area in which the same effect can be achieved.

[0035] On the other hand, expressions such as "comprise", "contain", "have", "exhibit" and "constitute" should not be understood as excluding other components.

[0036] Fig. Figure 1 is a schematic configuration diagram of a gas turbine 1 according to an embodiment.

[0037] As in Fig. As shown in Figure 1, the gas turbine 1 contains a compressor 2 for generating compressed air, a combustion chamber 4 for generating combustion gas from the compressed air and fuel, and a turbine 6 configured to be set in rotation by the combustion gas. In the case of the gas turbine 1 for power generation, a generator (not shown) is connected to the turbine 6.

[0038] The compressor 2 contains a plurality of compressor stator guide vanes 16, which are attached to a compressor housing 10, and a plurality of compressor rotor blades 18, which are implemented on a rotor shaft 8 such that they are arranged alternately with the compressor stator guide vanes 16. Air is supplied to the compressor 2, which is drawn in through an air inlet 12. The air flows through the plurality of compressor stator guide vanes 16 and the plurality of compressor rotor blades 18 and is compressed into compressed air at high temperature and high pressure.

[0039] Combustion chamber 4 is supplied with fuel and the compressed air generated in compressor 2. Combustion chamber 4 burns the fuel, producing combustion gas that serves as the working fluid for turbine 6. As described in Fig. As shown in Figure 1, the gas turbine 1 has a plurality of combustion chambers 4 arranged along the circumferential direction around the rotor shaft 8 within a casing 20.

[0040] The turbine 6 has a combustion gas channel 28 formed by a turbine housing 22 and contains a plurality of turbine stator guide vanes 24 and a plurality of turbine rotor blades 26 arranged in the combustion gas channel 28. The turbine stator guide vanes 24 are attached to the turbine housing 22, and a set of turbine stator guide vanes 24 arranged along the circumferential direction of the rotor shaft 8 forms a stator guide vane assembly. Furthermore, the turbine rotor blades 26 are implemented on the rotor shaft 8, and a set of turbine rotor blades 26 arranged along the circumferential direction of the rotor shaft 8 forms a rotor blade assembly. The stator guide vane assemblies and the rotor blade assemblies are arranged alternately in the axial direction of the rotor shaft 8.

[0041] In the turbine 6, the rotor shaft 8 is set in rotation when the combustion gas, introduced from the combustion chamber 4 into the combustion gas channel 28, flows through the plurality of turbine stator guide vanes 24 and the plurality of turbine rotor blades 26. This drives the generator connected to the rotor shaft 8 to produce electricity. The combustion gas that has driven the turbine 6 is discharged to the outside via an exhaust chamber 30.

[0042] Fig. Figure 2 is a schematic configuration diagram of the turbine rotor blade 26 according to one embodiment. Fig. 3 is a partial view of a cross-section of the in Fig. 2 turbine blade 26 shown in a first area S1, perpendicular to the blade height direction (radial direction of the rotor shaft 8). Fig. 4 is a partial view of a cross-section of the in Fig. 2 turbine rotor blade 26 shown in a second area S2, perpendicular to the rotor blade height direction.

[0043] As in Fig. As shown in Figure 2, the turbine rotor blade 26 includes a foot section 32 attached to the rotor shaft 8 (see Figure 2). Fig. 1) and a profile section 36 with a profile cross-section. A blade surface 50 of the profile section 36 includes a leading edge 38, a trailing edge 40, a pressure surface 42, and a suction surface 44. The radius of curvature R of the blade surface 50 at a leading edge section 46 in a cross-section perpendicular to the blade height direction, which is in Fig. 3 and Fig. As shown in section 4, it takes on a direction towards a blade tip 56 (tip of the profile section 36 in the blade height direction), which in Fig. 2 is shown, from.

[0044] As in Fig. As shown in Figure 2, the leading edge section 46 of the profile section 36 has a plurality of cooling holes 48. The plurality of cooling holes 48 of the leading edge section 46 includes a plurality of cooling hole rows 48A, 48B, 48C, each arranged linearly along the blade height direction in the first region S1 in the blade height direction.

[0045] The multiple cooling hole rows 48A, 48B, 48C include a pressure-side cooling hole row 48A formed on the pressure surface 42, a suction-side cooling hole row 48B formed on the suction surface 44, and a middle cooling hole row 48C formed between the pressure-side cooling hole row 48A and the suction-side cooling hole row 48B.

[0046] The pressure-side cooling hole row 48A is formed from a plurality of cooling holes 48 arranged along a first virtual line V1 extending linearly along the blade height direction. The suction-side cooling hole row 48B is formed from a plurality of cooling holes 48 arranged along a second virtual line V2 extending linearly along the blade height direction. The middle cooling hole row 48C is formed from a plurality of cooling holes 48 arranged along a third virtual line V3 extending linearly along the blade height direction. The cooling holes 48 formed in the first region S1 of the leading edge section 46 are arranged in a staggered pattern. In the illustrated exemplary embodiment, a rounded section 58 is formed at the boundary between a hub surface 54 of the turbine blade 26 and the blade surface 50 of the profile section 36.The rounding section 58 has no cooling holes 48. The upper end of the rounding section 58 corresponds to the lower end of the first area S1.

[0047] The plurality of cooling holes 48 of the leading edge section 46 includes a plurality of cooling hole rows 48D, 48E, each arranged linearly along the blade height direction in the second region S2 on the blade tip side 56 of the first region S1. The first region S1 and the second region S2 are adjacent to each other in the blade height direction. In the illustrated exemplary embodiment, the second region S2 is located between the position at half the blade height H and the blade tip 56. For example, the second region S2 is a region extending from the position at two-thirds of the blade height H to the blade tip 56. Here, the blade height H represents the height of the turbine blade 26 along the radial direction of the rotor shaft 8 from the hub surface 54 to the blade tip 56.

[0048] The plurality of cooling hole rows 48D, 48E comprises a pressure-side cooling hole row 48D, formed on the pressure surface 42, and a suction-side cooling hole row 48E, formed on the suction surface 44. The pressure-side cooling hole row 48D is formed from a plurality of cooling holes 48 arranged along the first virtual line V1. The suction-side cooling hole row 48E is formed from a plurality of cooling holes 48 arranged along the second virtual line V2. The cooling holes 48 formed in the second region S2 of the leading-edge section 46 are arranged in a staggered pattern.

[0049] In the illustrated exemplary embodiment, the number of cooling hole rows 48A, 48B, 48C in the first region S1 of the leading edge section 46 is 3, and the number of cooling hole rows 48D, 48E in the second region S2 of the leading edge section 46 is 2. Thus, the number of cooling hole rows 48D, 48E in the second region S2 of the leading edge section 46 is set to be less than the number of cooling hole rows 48A, 48B, 48C in the first region S1.Furthermore, n / b < m / a is satisfied, where m is the number of cooling holes 48 arranged in the first region S1 from the plurality of cooling holes 48 of the leading edge section 46 (provided that m is an integer of 2 or more), n is the number of cooling holes 48 arranged in the second region S2 from the plurality of cooling holes 48 of the leading edge section 46 (provided that n is an integer of 2 or more), a is the dimension of the first region S1 in the blade height direction, and b is the dimension of the second region S2 in the blade height direction. That is, a value obtained by dividing n by b is smaller than a value obtained by dividing m by a.

[0050] As in Fig. 3 and Fig. As shown in Figure 4, a cooling channel 52, extending along the blade height direction, is formed within the profile section 36, and each cooling hole 48 of the leading edge section 46 communicates with the cooling channel 52. The cooling channel 52 is connected to a portion of the compressor 2 (see Figure 4). Fig. 1) The generated compressed air is supplied as cooling air. The cooling air flows from the cooling channel 52 to each cooling opening 58 and is used for film cooling of the rotor blade surface 50.

[0051] As in Fig. As shown in Figure 3, each cooling hole 48 of the pressure-side cooling hole row 48A extends along a direction parallel to a first straight line L1 that intersects the pressure surface 42. Each cooling hole 48 of the suction-side cooling hole row 48B extends along a direction parallel to a second straight line L2 that intersects the suction surface 44.

[0052] As in Fig. As shown in Figure 4, each cooling hole 48 of the pressure-side cooling hole row 48D extends in a direction parallel to a third straight line L3 that intersects the pressure surface 42. Each cooling hole 48 of the suction-side cooling hole row 48E extends in a direction parallel to a fourth straight line L4 that intersects the suction surface 44. The angle θ2 between the third straight line L3 and the fourth straight line L4 is equal to the angle θ1 between the first straight line L1 and the second straight line L2.

[0053] As in Fig. Figure 3 shows that if X is defined as a distance between the first virtual line V1 and the second virtual line V2 at the same position in the blade height direction on the blade surface 50, and Y is defined as a distance between the second virtual line V2 and the third virtual line V3 at the same position in the blade height direction on the blade surface 50, then a relationship exists between the blade height direction position h and the distance X, Y in Fig. Figure 5 shows the blade height direction position h, which represents a distance from the hub surface 54 in the blade height direction.

[0054] As in Fig. 5 shown, if Ymax is defined as a maximum value of the distance Y in the first region S1 and h1 is defined as a position in the blade height direction such that the distance X is less than the distance Ymax, the second region S2 is located between the position h1 and the blade tip 56.

[0055] With the above configuration, even if the radius of curvature R of the blade surface 50 of the leading edge section 46 decreases towards the blade tip 56, because the number of cooling hole rows 48D, 48E in the second area S2 is set to be less than the number of cooling hole rows 48A, 48B, 48C in the first area S1, n / b < m / a, it is possible to prevent an excessive amount of cooling air from being supplied to the cooling hole rows 48D, 48E in the second area S2. Thus, the amount of cooling air supplied to the cooling holes 48 in the first area S1 and the amount of cooling air supplied to the cooling holes 48 in the second area S2 can be optimized, and the leading edge section 46 can be effectively cooled with a small amount of cooling air.

[0056] Furthermore, the distance between the cooling hole row 48D and the cooling hole row 48E in the second region S2 can be smaller than the distance Ymax, even if the number of cooling hole rows 48D, 48E in the second region S2 is less than the number of cooling hole rows 48A, 48B, 48C in the first region S1, since the second region S2 is located between position h1 and the blade tip 56. This prevents the cooling air supply to the cooling hole rows 48D, 48E in the second region S2 from being insufficient. Thus, the cooling air supply to the cooling holes 48 in the first region S1 and the cooling air supply to the cooling holes 48 in the second region S2 can be optimized, and the leading edge section 46 can be effectively cooled with a small cooling air volume.

[0057] Further embodiments will now be described.

[0058] Fig. Figure 6 is a schematic configuration diagram of the turbine rotor blade 26 according to one embodiment. The in Fig. The embodiment shown in 6 differs from the one shown in Fig. 2. In the embodiment shown, only in the configuration of the pressure-side cooling hole row 48D and the suction-side cooling hole row 48E; in particular, the distance between the pressure-side cooling hole row 48D and the suction-side cooling hole row 48E in the second region S2 is set closer than in the embodiment shown in Figure 2. Fig. 2. Since the other configurations are identical to those of the embodiment described above, the configuration that differs from the embodiment described above is described below.

[0059] In the Fig. In the embodiment shown in Figure 6, the pressure-side cooling hole row 48D is formed from a plurality of cooling holes 48 arranged along a fourth virtual line V4 extending linearly along the blade height direction. The suction-side cooling hole row 48B is formed from a plurality of cooling holes 48 arranged along a fifth virtual line V5 extending linearly along the blade height direction. Here, in the second region S2, the fourth virtual line V4 is located closer to the leading edge 38 than the first virtual line V1, and the fifth virtual line V5 is located closer to the leading edge 38 than the second virtual line V2.

[0060] Fig. 7 is a partial view of a cross-section of the in Fig. The turbine rotor blade 26 shown in section 6 is located in the second area S2, perpendicular to the blade height direction. The configuration of the turbine rotor blade shown in section 6 is located in the second area S2, perpendicular to the rotor blade height direction. Fig. The cross-section of the turbine rotor blade 26 shown in Figure 6, in the first area S1 perpendicular to the rotor blade height direction, is not described, as it is the same as the one shown in Figure 6. Fig. 3 configurations shown.

[0061] As in Fig. As shown in Figure 7, each cooling hole 48 of the pressure-side cooling hole row 48D extends along a direction parallel to a third straight line L3 that intersects the pressure surface 42. Each cooling hole 48 of the suction-side cooling hole row 48E extends along a direction parallel to a fourth straight line L4 that intersects the suction surface 44. The angle θ2 between the third straight line L3 and the fourth straight line L4 in the second region S2 is smaller than the angle θ1 (see Figure 7). Fig. 3) between the first straight line L1 and the second straight line L2 in the first area S1.

[0062] As in Fig. 3 and Fig. Figure 7 shows that if X is defined as a distance between the first virtual line V1 and the second virtual line V2 at the same position in the blade height direction on the blade surface 50, Y is defined as a distance between the second virtual line V2 and the third virtual line V3 at the same position in the blade height direction on the blade surface 50, and Z is defined as a distance between the fourth virtual line V4 and the fifth virtual line V5 at the same position in the blade height direction on the blade surface 50, then a relationship exists between the blade height direction position h and the distance X, Y, Z in Fig. 8 shown.

[0063] In the Fig. In the configuration shown in Figure 8, if Ymax is defined as a maximum value of the distance Y in the first area S1 and h1 is defined as a position in the blade height direction such that the distance X is less than the distance Ymax, the second area S2 is located between the position h1 and the blade tip 56.

[0064] As in Fig. As shown in Figure 8, in the second area S2 the distance Z between the fourth virtual line V4 and the fifth virtual line V5 at the same position in the blade height direction on the blade surface 50 is set such that it is smaller than the distance X between the first virtual line V1 and the second virtual line V2 at the same position in the blade height direction on the blade surface 50.

[0065] With the in Fig. The configuration shown in Figures 6 to 8 is, in the same manner as described above, effective even if the radius of curvature R of the blade surface 50 of the leading edge section 46 decreases towards the blade tip 56, because the number of cooling hole rows 48D, 48E in the second region S2 is set to be less than the number of cooling hole rows 48A, 48B, 48C in the first region S1, n / b < m / a, thus preventing an excessive amount of cooling air from being supplied to the cooling hole rows 48D, 48E in the second region S2. Therefore, the amount of cooling air supplied to the cooling holes 48 in the first region S1 and the amount of cooling air supplied to the cooling holes 48 in the second region S2 can be optimized, and the leading edge section 46 can be effectively cooled with a small amount of cooling air.

[0066] Furthermore, the distance between the cooling hole row 48D and the cooling hole row 48E in the second region S2 can be smaller than the distance Ymax, even if the number of cooling hole rows 48D, 48E in the second region S2 is less than the number of cooling hole rows 48A, 48B, 48C in the first region S1, since the second region S2 is located between position h1 and the blade tip 56. This prevents the cooling air supply to the cooling hole rows 48D, 48E in the second region S2 from being insufficient. Thus, the cooling air supply to the cooling holes 48 in the first region S1 and the cooling air supply to the cooling holes 48 in the second region S2 can be optimized, and the leading edge section 46 can be effectively cooled with a small cooling air volume.

[0067] Furthermore, since the angle θ2 between the third straight line L3 and the fourth straight line L4 is smaller than the angle θ1 between the first straight line L1 and the second straight line L2, the leading edge section 46 exposed to the hot gas can be effectively cooled from the pressure surface 42 to the suction surface 44 with a small amount of cooling air.

[0068] For example, in the embodiments described above, the number of cooling hole rows 48D, 48E in the second region S2 is smaller than the number of cooling hole rows 48A, 48B, 48C in the first region S1. However, the ratio between the number of cooling hole rows in the second region S2 and the number of cooling hole rows in the first region is not limited, as long as the plurality of cooling holes 48 of the leading edge section 46 satisfies n / b < m / a. For example, as in Fig. Figure 9 shows that the number of cooling hole rows 48D, 48E, 48F in the second area S2 is equal to the number of cooling hole rows 48A, 48B, 48C in the first area S1, or, as shown in Fig. As shown in Figure 10, the number of cooling hole rows 48D, 48E, 48F, 48G in the second area S2 can be greater than the number of cooling hole rows 48A, 48B, 48C in the first area S1.

[0069] In the Fig. In the embodiment shown in Figure 9, the number of cooling hole rows 48D, 48E, 48F in the second area S2 is equal to the number of cooling hole rows 48A, 48B, 48C in the first area S1, but the distance between the cooling holes 48 of the cooling hole row 48F in the second area S2 is greater than the distance between the cooling holes 48 of the cooling hole row 48C in the first area S1, so that n / b < m / a is satisfied.

[0070] Alternatively, in the Fig.In the embodiment shown in Figure 10, the number of cooling hole rows 48D, 48E, 48F, 48G in the second region S2 is greater than the number of cooling hole rows 48A, 48B, 48C in the first region S1, but the distance (distance in the blade height direction) between the cooling holes 48 of each cooling hole row 48D, 48E, 48F, 48G in the second region S2 is greater than the distance (distance in the blade height direction) between the cooling holes 48 of each cooling hole row 48A, 48B, 48C in the first region S1, so that n / b < m / a is satisfied.

[0071] Thus, if n / b < m / a is satisfied, the amount of cooling air supplied to the cooling holes in the first area and the amount of cooling air supplied to the cooling holes in the second area can be optimized, and the leading edge section can be effectively cooled with a small amount of cooling air. Reference symbol list 1 gas turbine 2 compressors 4 Combustion chamber 6 Turbine 26 Turbine rotor blades 36 Profile section 38 Front edge 42 printing area 44 suction area 46 Leading edge section 48 cooling holes 48A, 48D Pressure-side cooling hole row 48B, 48E Suction-side cooling hole row 48C Middle cooling hole row 50 blade surface 54 Hub surface 56 Runner blade tip 58 Rounding section S1 First Area S2 Second Area V1 First virtual line V2 Second virtual line V3 Third virtual line

Claims

[1] Turbine rotor blade (26) having a leading edge section (46) with a plurality of cooling holes (48), which has a multitude of cooling holes (48): m cooling holes (48) arranged in a first region (S1) in a rotor blade height direction, where m is an integer of 2 or more; and n cooling holes (48) arranged in a second region (S2) on a blade tip side of the first region (S1) in the blade height direction, where n is an integer of 2 or more, and where n / b < m / a is satisfied, where a is a dimension of the first region (S1) in the blade height direction and b is a dimension of the second region (S2) in the blade height direction, which has a multitude of cooling holes (48): a plurality of cooling hole rows (48A, 48B, 48C), each of which is arranged along the blade height direction in the first area (S1); and at least one cooling hole row (48D, 48E), each of which is arranged along the blade height direction in the second area (S2), and where the number of cooling hole rows (48D, 48E) in the second area (S2) is less than the number of cooling hole rows (48A, 48B, 48C) in the first area (S1), where the number of cooling hole rows (48A, 48B, 48C) in the first area (S1) is 3, and where the number of cooling hole rows (48D, 48E) in the second area (S2) is 2, wherein the plurality of cooling hole rows (48A, 48B, 48C) in the first region (S1) comprises a pressure-side cooling hole row (48A) formed on a pressure surface, a suction-side cooling hole row (48B) formed on a suction surface, and a middle cooling hole row (48C) formed between the pressure-side cooling hole row (48A) and the suction-side cooling hole row (48B), and wherein the at least one cooling hole row (48D, 48E) in the second area (S2) has a pressure-side cooling hole row (48D) formed on the pressure surface and a suction-side cooling hole row (48E) formed on the suction surface, characterized by , that The pressure-side cooling hole row (48A) in the first area (S1) is arranged along a first virtual line (V1) which is linear, wherein the suction-side cooling hole row (48B) in the first area (S1) is arranged along a second virtual line (V2) which is linear, wherein the middle cooling hole row (48C) is arranged along a third virtual line (V3) which is linear, and whereupon X is defined as a distance between the first virtual line (V1) and the second virtual line (V2) at the same position in the blade height direction on the blade surface (50), Y is defined as a distance between the second virtual line (V2) and the third virtual line (V3) at the same position in the blade height direction on the blade surface (50), Ymax is defined as a maximum value of the distance Y in the first region (S1), and h1 is defined as a position in the blade height direction such that the distance X is smaller than the distance Ymax, the second area (S2) is located between the position h1 and the blade tip (56), wherein the turbine rotor blade (26) further comprises: a profile section (36) containing the leading edge section (46), a hub surface (54) which is connected to the blade surface (50) of the profile section (36) via a rounding section (58), where the lower end of the first area (S1) is the upper end of the rounding section (58) in the direction of the blade height. [2] Turbine rotor blade (26) according to claim 1, wherein a radius of curvature of the rotor blade surface (50) of the leading edge section (46) decreases in a cross-section perpendicular to the rotor blade height direction in the direction of the rotor blade tip (56). [3] Turbine rotor blade (26) according to claim 1 or 2, wherein the second region (S2) is located between a position at half a rotor blade height and the rotor blade tip (56). [4] Turbine rotor blade (26) according to claim 3, wherein the second region (S2) has a region from a position at two thirds of the rotor blade height to the rotor blade tip (56). [5] Turbine rotor blade (26) according to one of claims 1 to 4, in which each of the cooling holes of the pressure-side cooling hole row (48A) extends in the first area (S1) along a direction parallel to a first straight line intersecting the pressure surface, wherein each of the cooling holes of the suction-side cooling hole row (48B) extends in the first area (S1) along a direction parallel to a second straight line intersecting the suction surface, wherein each of the cooling holes of the pressure-side cooling hole row (48D) in the second area (S2) extends along a direction parallel to a third straight line intersecting the pressure surface, wherein each of the cooling holes of the suction-side cooling hole row (48E) in the second area (S2) extends along a direction parallel to a fourth straight line intersecting the suction surface, and where the angle between the third straight line and the fourth straight line is smaller than the angle between the first straight line and the second straight line. [6] Gas turbine (1), comprising: a compressor (2) for producing compressed air; a combustion chamber (4) for producing combustion gas using compressed air and fuel; and a turbine (6) configured to be driven by the combustion gas, wherein the turbine (6) comprises the turbine rotor blade (26) according to any one of claims 1 to 5.

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