JP7254668B2 - Turbine blade and gas turbine provided with the same - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to turbine blades and gas turbines having the same.

2. Description of the Related Art In turbine blades such as gas turbines, it is known to cool turbine blades exposed to a high-temperature gas flow by flowing a cooling medium (such as air) through flow paths formed inside the turbine blades.

For example, Patent Literature 1 discloses a turbine blade in which a meandering flow path (serpentine flow path) formed by a plurality of cooling passages extending along the blade height direction is provided inside the blade portion. This serpentine channel (cooling channel) includes a ventral (pressure side) channel and a back (suction side) channel separated by a back-to-back separation wall. The cooling medium that has flowed into the ventral passage from the root of the turbine blade flows radially outward through the ventral passage, then turns back at the tip of the blade and flows radially inward through the ventral passage. It has become. A part of the cooling medium flowing through the ventral passage and the dorsal passage passes through a plurality of film holes formed in the turbine blade so as to communicate from the ventral passage and the dorsal passage to the blade surface. It is designed to be discharged to the outside. In addition to the meandering flow path (cooling flow path) described above, the leading edge of the turbine blade is provided with a cooling passage extending along the blade height direction. The cooling medium supplied from the root portion of the blade to the cooling passage of the leading edge portion is discharged to the outside of the turbine blade through a cooling hole (shower head) leading from the cooling passage to the blade surface of the leading edge portion. ing.

JP-A-7-189603

By the way, when the cooling medium supplied to the cooling flow path inside the turbine blade is discharged from the cooling flow path before the temperature rises much (that is, in a state where the cooling capacity remains), the cooling flow of the turbine blade A large amount of cooling medium is supplied to the passage, which may lead to a decrease in the efficiency of the entire turbine system. Therefore, it is desirable to suppress an increase in the amount of cooling medium supplied to the cooling passages of the turbine blades.

In view of the circumstances described above, at least one embodiment of the present invention aims to provide a turbine blade capable of suppressing an increase in the amount of cooling medium supplied, and a gas turbine including the same.

A turbine blade according to at least one embodiment of the present invention comprises:
an airfoil extending in the height direction and having pressure and suction surfaces extending between leading and trailing edges;
a plurality of cavities each extending along the airfoil height direction at least inside the airfoil;
the plurality of cavities include a leading edge side cavity, a pressure side cavity, and a suction side cavity that communicate with each other to form a meandering flow path;
wherein the leading edge side cavity is positioned closest to the leading edge in the chord direction of the airfoil portion among the plurality of cavities;
The pressure side cavity is located on the trailing edge side of the leading edge side cavity in the chord direction, and is connected to the leading edge side cavity via a first return portion on the base side of the airfoil portion in the blade height direction. connected and
The suction side cavity is positioned so as to at least partially overlap with the pressure side cavity on the trailing edge side of the leading edge side cavity in the chord direction, and on the tip side of the airfoil portion in the blade height direction. is connected to the pressure side cavity via the second return part of
An exit hole is formed at the leading edge of the airfoil and communicates with the leading edge cavity and opens to the surface of the airfoil at the leading edge.

Further, a gas turbine according to at least one embodiment of the present invention includes the above-described turbine blades, and a combustor for generating combustion gas flowing through a combustion gas flow path provided with the turbine blades.

According to at least one embodiment of the present invention, a turbine blade capable of suppressing an increase in the amount of cooling medium supplied and a gas turbine including the same are provided.

1 is a schematic configuration diagram of a gas turbine according to one embodiment; FIG. 1 is a schematic diagram of a turbine blade according to one embodiment; FIG. FIG. 3 is a schematic cross-sectional view orthogonal to the blade height direction of the turbine blade shown in FIG. 2 ; 4 is a schematic cross-sectional view taken along line BB of FIG. 3; FIG. 4 is a schematic cross-sectional view taken along line CC of FIG. 3; FIG. 1 is a schematic cross-sectional view of a platform of a turbine blade according to one embodiment; FIG. 1 is a schematic cross-sectional view of a platform of a turbine blade according to one embodiment; FIG.

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

(Configuration of gas turbine)
First, a gas turbine to which turbine blades according to some embodiments are applied will be described.
FIG. 1 is a schematic configuration diagram of a gas turbine to which a turbine blade according to one embodiment is applied. As shown in FIG. 1, a gas turbine 1 includes a compressor 2 for generating compressed air, a combustor 4 for generating combustion gas using the compressed air and fuel, and a combustion gas that is rotationally driven. a turbine 6 configured to: In the case of the gas turbine 1 for power generation, the turbine 6 is connected with a generator (not shown).

The compressor 2 includes a plurality of stator blades 16 fixed to the compressor casing 10 side, and a plurality of rotor blades 18 implanted in the rotor 8 so as to be alternately arranged with respect to the stator blades 16. . Air taken in from an air intake port 12 is sent to the compressor 2, and this air passes through a plurality of stationary blades 16 and a plurality of moving blades 18 and is compressed to produce a high temperature and high pressure. of compressed air.

Fuel and compressed air generated by the compressor 2 are supplied to the combustor 4 , and the fuel and compressed air are mixed and combusted in the combustor 4 to produce a working fluid for the turbine 6 . is produced. As shown in FIG. 1 , a plurality of combustors 4 may be arranged in the casing 20 along the circumferential direction around the rotor.

The turbine 6 has a combustion gas flow path 28 formed within the turbine casing 22 and includes a plurality of stator vanes 24 and rotor blades 26 provided in the combustion gas flow path 28 . The stationary blades 24 are fixed on the turbine casing 22 side, and a plurality of stationary blades 24 arranged along the circumferential direction of the rotor 8 form a row of stationary blades. Further, the rotor blades 26 are implanted in the rotor 8, and a plurality of rotor blades 26 arranged along the circumferential direction of the rotor 8 form a rotor blade cascade. The row of stationary blades and row of moving blades are alternately arranged in the axial direction of the rotor 8 .

In the turbine 6 , the combustion gas from the combustor 4 that has flowed into the combustion gas flow path 28 passes through the plurality of stationary blades 24 and the plurality of moving blades 26 , thereby driving the rotor 8 to rotate. A power generator is driven to generate electric power. Combustion gas after driving the turbine 6 is discharged to the outside through the exhaust chamber 29 .

In some embodiments, at least one of the rotor blades 26 or the stator blades 24 of the turbine 6 are turbine blades 30, described below.

(Configuration of turbine blade)
Hereinafter, turbine blades 30 according to some embodiments will be described in more detail. FIG. 2 is a schematic diagram of a turbine blade 30 (rotating blade 26) according to one embodiment, viewed from the suction surface toward the pressure surface (direction along the circumferential direction of the rotor). 3 is a schematic cross-sectional view orthogonal to the blade height direction of the turbine blade 30 shown in FIG. 2, and is a cross-sectional view taken along line AA in FIG. 4 is a schematic cross-sectional view taken along line BB of FIG. 3, and FIG. 5 is a schematic cross-sectional view taken along line CC of FIG. 6 and 7 are schematic cross-sectional views of the platform of the turbine blade 30 according to one embodiment, and correspond to cross-sectional views taken along line DD in FIG.
Although the turbine blade 30 will be described below with reference to the drawing of the moving blade 26, basically the same description can be applied to the stationary blade 24 as the turbine blade 30 as well.

As shown in FIGS. 2-5 , a turbine blade 30 (rotating blade 26 ) according to one embodiment includes a platform 32 , an airfoil portion 34 and a blade root portion 36 connected to the platform 32 .

The airfoil portion 34 extends in the wing height direction (span direction), has a base end 38 and a tip 40 which are both ends in the wing height direction, and is connected to the platform 32 at the base end 38 side. ing. The airfoil 34 also has a leading edge 42 and a trailing edge 44 extending along the blade height, and a pressure surface 46 and a suction surface 48 extending between the leading edge 42 and the trailing edge 44 . .

The blade root portion 36 is located on the opposite side of the airfoil portion 34 across the platform 32 in the blade height direction. The blade root portion 36 includes an engaging portion 37 having an uneven shape, and the engaging portion 37 is engaged with a blade groove provided in a rotor disk (not shown) that rotates together with the rotor 8, whereby the turbine blade 30 is attached to the rotor 8 of the turbine 6 .

Note that when the turbine blades 30 are attached to the rotor 8 , the blade height direction is the direction along the radial direction of the turbine 6 . That is, the blade height direction of the turbine blades 30 substantially coincides with the radial direction of the turbine 6 .

As shown in FIGS. 3-5, the turbine blade 30 includes a plurality of cavities 52, 54, 56, 62, 64, 66 respectively extending along the blade height direction within at least the airfoil portion 34. ing. In the exemplary embodiment shown in FIGS. 3-5, ribs 76a-76d and partitions 58 are provided between adjacent cavities extending along the blade height direction to partition the interior space of the airfoil 34. A plurality of cavities are formed by the inner wall surface 34a of the airfoil portion 34, the ribs 76a to 76d and the partition wall 58. As shown in FIG.

Of the plurality of cavities described above, the leading edge side cavity 52 , the pressure side cavity 54 , and the suction side cavity 56 communicate with each other to form a meandering flow path (serpentine flow path) 50 .

Of the plurality of cavities described above, the leading edge side cavity 52 is the most leading edge 42 in the chord direction of the airfoil portion 34 (the direction connecting the leading edge 42 and the trailing edge 44 in the cross section orthogonal to the blade height direction; see FIG. 3). side cavity.

The pressure side cavity 54 and the suction side cavity 56 are positioned closer to the trailing edge 44 than the leading edge side cavity 52 in the chord direction. Also, the pressure side cavity 54 and the suction side cavity 56 are positioned so as to at least partially overlap each other in the chord direction. In a cross-wing cross-section (see FIG. 3), the pressure side cavity 54 is located at least partially between the suction side cavity 56 and the pressure side 46 . In addition, the suction side cavity 56 is located at least partially between the pressure side cavity 54 and the suction side 48 in a cross section perpendicular to the blade height direction.

The pressure surface side cavity 54 is connected to the leading edge side cavity 52 via a first return portion 53 located on the base end 38 side in the blade height direction (that is, radially inward). The suction side cavity 56 is connected to the pressure side cavity 54 via a second return portion 55 located on the tip 40 side in the blade height direction (that is, radially outward).

A turbine blade 30 according to one embodiment is formed at a leading edge portion 43 of an airfoil portion 34 , communicates with a leading edge side cavity 52 , and opens to a surface (outer surface) 34 b of the airfoil portion 34 at the leading edge portion 43 . An exit hole 70 is further provided.

As shown in FIGS. 3 and 4 , the exit holes 70 may include a plurality of leading edge exit holes (film holes) 72 arranged along the blade height at the leading edge 43 of the airfoil 34 . . 3 and 4, the exit holes 70 may also include tip exit holes 74 provided in the tip portion 41 of the airfoil 34. As shown in FIG.

A cooling medium (for example, air) is supplied to the meandering flow path 50 formed inside the turbine blade 30 through an inlet opening 51 opening at the end of the blade root portion 36 of the turbine blade 30 . . The turbine blades 30 may be supplied with, for example, a portion of the compressed air generated by the compressor 2 (see FIG. 1) as a cooling medium.

3 to 5, the cooling medium introduced into the meandering flow path 50 through the inlet opening 51 opening at the end of the blade root portion 36 of the turbine blade 30 flows through the suction side cavity 56. It flows from the base end 38 side toward the tip 40 side (that is, radially outward), and flows into the pressure side cavity 54 via the second return portion 55 located on the downstream end side of the suction side cavity 56 . Then, the cooling medium flows in the pressure side cavity 54 from the distal end 40 side toward the base end 38 side (that is, radially inward), and flows through the first return located on the downstream end side of the pressure side cavity 54 . It flows into the leading edge side cavity 52 via the portion 53 . The cooling medium then flows through the leading edge cavity 52 from the proximal end 38 side toward the distal end 40 side (i.e., radially outward), and a portion of the cooling medium flows through the leading edge exit hole 72 (exit hole 72). 70) to the outside of the turbine blade 30, and another part of the cooling medium is discharged to the outside of the turbine blade 30 through the tip outlet hole 74 (the outlet hole 70).

As the cooling medium flows through the serpentine flow path 50 including the suction side cavity 56 , the pressure side cavity 54 and the leading edge side cavity 52 , it convectively cools the inner wall surface of the serpentine flow path 50 . In addition, the cooling medium discharged to the outside of the turbine blade 30 from the outlet holes 70 (the leading edge outlet holes 72 or the tip outlet holes 74) forms a film covering the surface 34b of the airfoil 34, cooling the surface 34b. It may be designed to

The wall surface forming each cavity (the inner wall surface 34a of the airfoil portion 34, the surface of the ribs 76a to 76d, or the partition wall 58) may be provided with a turbulator for promoting convection cooling by the cooling medium. .

In the turbine blade 30 according to the above-described embodiment, the pressure side cavity 54 and the suction side cavity 56 forming the meandering flow path 50 through which the cooling medium flows are separately provided and connected via the second return portion 55. After passing through the suction side cavity 56 , the cooling medium can flow to the pressure side cavity 54 . Therefore, compared to the case of cooling both the pressure surface 46 side and the suction surface 48 side of the airfoil portion 34 with one cavity, the airfoil can be cooled while preventing overcooling of the pressure surface 46 side, which has a relatively small heat load. The turbine blades 30 including the features 34 can be effectively cooled. Further, the pressure surface side cavity 54 and the leading edge side cavity 52 are connected via the first return portion 53, and an outlet hole 70 (the leading edge outlet hole 72 and the tip outlet hole 74) communicating with the leading edge side cavity 52 is provided. Therefore, the cooling medium that has passed through the pressure surface side cavity 54 can flow into the leading edge side cavity 52 via the first return portion 53 and can be discharged to the outside of the turbine blade 30 via the outlet holes 70 .
That is, by supplying the cooling medium that has cooled the airfoil portion 34 by flowing through the suction side cavity 56 and the pressure side cavity 54 to the leading edge side cavity 52, the remaining cooling capacity can be used to utilize the remaining cooling capacity of the airfoil. 34 and cooling the airfoil portion 34, the cooling medium whose temperature has risen can be discharged from the outlet hole 70 and used for film cooling of the turbine blade 30 or the like. Therefore, according to the above-described embodiment, the cooling medium can be effectively utilized while cooling the pressure surface 46 side and the suction surface 48 side, which have different heat loads, in a well-balanced manner, and the amount of cooling medium supplied to the turbine blades 30 is increased. can be suppressed.

Note that in some embodiments, a cooling channel other than the meandering channel 50 may be further provided inside the turbine blade 30 . For example, in the exemplary embodiment shown in FIGS. 3 to 5, the turbine blade 30 is further provided with a serpentine passage 60 positioned closer to the trailing edge 44 in the cord direction than the serpentine passage 50 described above. there is

As shown in FIGS. 3 and 4, the serpentine flow path 60 includes a cavity 62, a cavity 64 connected to the cavity 62 via a return section 63, and a cavity 66 connected to the cavity 64 via a return section 65. and including. The cavity 66 is positioned closest to the trailing edge in the chord direction among the plurality of cavities provided inside the turbine blade 30 . The trailing edge 45 of the airfoil 34 is provided with outlet holes 68 , 69 that communicate with the cavity 66 and open to the surface of the airfoil 34 at the trailing edge 45 .

A cooling medium (for example, air) is supplied to the meandering flow path 60 through an inlet opening 61 opening at the end of the blade root portion 36 of the turbine blade 30 . The cooling medium introduced into the meandering flow path 60 through the inlet opening 61 flows through the cavity 62 from the proximal end 38 side toward the distal end 40 side and flows into the cavity 64 via the return portion 63 . Then, the cooling medium flows in the cavity 64 from the distal end 40 side toward the proximal end 38 side and flows into the cavity 66 via the return portion 65 . Then, the cooling medium flows in the cavity 66 from the base end 38 side toward the tip end 40 side, and part of the cooling medium flows out of the turbine blade 30 through the outlet hole 69 provided in the trailing edge portion 45 . Another part of the cooling medium is discharged to the outside of the turbine blade 30 through the outlet hole 68 provided in the tip portion 41 .

In some embodiments, the turbine blade 30 is configured so that coolant supplied to the serpentine flow paths 50 exits the turbine blade 30 only through the exit holes 70 (the leading edge exit hole 72 and the tip exit hole 74). configured to be ejected. That is, the turbine blades 30 are configured such that the entire amount of the cooling medium supplied to the meandering flow paths 50 is discharged to the outside of the turbine blades 30 through the outlet holes 70 .

For example, in the exemplary embodiment shown in FIGS. 3-5, the airfoil 34 is provided with holes connected to the pressure side cavity 54 or the suction side cavity 56 and opening to the surface of the airfoil 34 . Not done. That is, the meandering flow path 50 formed inside the turbine blade 30 is a closed space with respect to the external space of the turbine blade 30 except for the outlet hole 70 and the inlet opening 51 . Therefore, after the entire amount of the cooling medium supplied to the turbine blades 30 through the inlet openings 51 passes through the suction side cavity 56 and the pressure side cavity 54 and is introduced into the leading edge side cavity 52, the outlet holes 70 ( It is discharged outside the turbine blade 30 via the leading edge exit hole 72 or the tip exit hole 74).

According to the above-described embodiment, all of the coolant supplied to the serpentine passages 50 is discharged outside the turbine blade 30 only through the outlet holes 70 leading from the leading edge side cavity 52 to the surface 34b of the airfoil 34. be done. That is, since all the cooling medium supplied to the suction side cavity 56 is led to the leading edge side cavity 52 via the pressure side cavity 54, the total amount of cooling medium supplied to the suction side cavity 56 is , the cooling medium can be discharged to the outside of the turbine blades 30 through the outlet holes 70 after the temperature is sufficiently raised and the cooling capacity is fully used. In this manner, the cooling medium can be effectively utilized to effectively cool the turbine blades 30 .

In some embodiments, between the inner wall surface 96 of the pressure side cavity 54 and the inner wall surface 98 of the suction side cavity 56 formed by the partition 58 between the pressure side cavity 54 and the suction side cavity 56 . A camber orthogonal distance w1 (see FIG. 3) increases as the trailing edge 44 is approached in the chord direction.
In some embodiments, the aforementioned distance w1 increases in at least some regions in the chord direction as it approaches the trailing edge 44 in the chord direction.
In some embodiments, at least in the region on the leading edge 42 side of the position where the thickness of the airfoil portion 34 (the size in the direction perpendicular to the chord direction) is greatest in the chord direction, the above-mentioned distance w1 is set in the chord direction. increases as it approaches the trailing edge 44 at .

In the embodiment described above, the distance w1 between the inner wall surfaces 96, 98 formed by the partition wall 58 separating the pressure side cavity 54 and the suction side cavity 56 increases as the trailing edge 44 is approached in the chord direction. As a result, the cross-sectional shape of the pressure side cavity 54 can be easily made along the pressure surface 46 , and the cross-sectional shape of the suction side cavity 56 can be easily made along the suction surface 48 . As a result, the thickness between the pressure surface 46 and the pressure surface side cavity 54 and the thickness between the suction surface 48 and the suction surface side cavity 56 can be easily reduced. The cooling medium flowing through the pressure side cavity 56 can cool the turbine blades 30 more effectively.

In some embodiments, the turbine blade 30 includes a platform cooling channel 80 formed within the platform 32, for example as shown in FIGS. Platform cooling channel 80 has a first end 82 connected to suction side cavity 56 and a second end 84 connected to leading edge side cavity 52 .

In the above-described embodiment, since the platform cooling channel 80 is provided inside the platform 32, part of the cooling medium flowing through the suction side cavity 56 (serpentine channel 50) is branched to form the platform cooling channel 80. , and the cooling medium that has passed through the platform cooling channel 80 can join the leading edge side cavity 52 (serpentine channel 50). Therefore, the platform 32 can be cooled using part of the cooling medium supplied to the meandering flow path 50, and the turbine blades 30 can be cooled more efficiently. After passing through the platform cooling flow path 80 , the cooling medium merges with the leading edge side cavity 52 and is discharged from the turbine blade 30 through the outlet hole 70 communicating with the leading edge side cavity 52 . Therefore, the remaining cooling capacity of the cooling medium after cooling the platform 32 is utilized to cool the airfoil portion, and the cooling medium whose temperature has risen is discharged from the outlet holes 70 for film cooling of the turbine blades 30 and the like. can be used. Therefore, according to the above-described embodiment, it is possible to effectively use the cooling medium and more effectively suppress an increase in the amount of cooling medium supplied to the turbine blades 30 .

Also, in the above-described embodiments, the difference in cooling load between the airfoil 34 and the platform 32 is taken into account for the amount of cooling medium distributed at the junction (the connection point between the suction side cavity 56 and the platform cooling channel 80). By setting the shapes (cross-sectional area, length, etc.) of the meandering channel 50 and the platform cooling channel 80 so that the distribution ratio is appropriate, The temperature difference between the cooling medium flowing into the leading edge side cavity 52 via the platform cooling channel 80 and the cooling medium flowing into the leading edge side cavity 52 via the platform cooling channel 80 can be reduced. Thereby, the turbine blades 30 can be cooled more effectively.

In some embodiments, the turbine blade 30 is configured such that coolant supplied to the platform cooling passage 80 via the first end 82 exits the platform cooling passage 80 only via the second end 84. configured as That is, turbine blade 30 is configured such that all of the coolant supplied to platform cooling passage 80 via first end 82 is discharged from platform cooling passage 80 via second end 84 . there is

For example, in the exemplary embodiment shown in FIGS. 6 and 7, the platform 32 is not provided with holes that communicate with the platform cooling passages 80 and open to the surface of the turbine blades 30 (eg, platform 32). , a platform cooling channel 80 formed inside the platform 32 is a closed space within the platform 32, except for a first end 82 and a second end 84. Therefore, from the suction side cavity 56 to the first All of the coolant entering platform cooling channel 80 via end 82 exits platform cooling channel 80 via second end 84 into the leading edge side cavity.

Therefore, according to the above-described embodiment, all the cooling medium supplied to the platform cooling channel 80 is led to the leading edge side cavity 52 via the second end 84, so that the cooling medium supplied to the platform cooling channel 80 is The total amount of coolant dispensed can be discharged to the leading edge side cavity 52 after the temperature has been raised sufficiently to fully utilize the cooling capacity. In this manner, the cooling medium can be effectively utilized to effectively cool the turbine blades 30 .

Further, in the above-described embodiment, the platform cooling channel 80 is provided inside the platform 32 , so the platform 32 can be cooled without providing cooling holes that open to the surface of the platform 32 . Therefore, the cooling medium that has cooled the platform 32 by flowing through the platform cooling channel 80 can be returned to the leading edge side cavity 52 and effectively utilized.

Hereinafter, the area of the platform 32 facing the pressure surface 46 is referred to as the pressure side area 102 , and the area of the platform 32 facing the suction surface 48 is referred to as the suction side area 104 . That is, in plan view (when viewed from the radial direction), the pressure surface side region 102 is the portion of the airfoil portion 34 (indicated by the dashed line in FIGS. 6 and 7) at the connection position 35 between the platform 32 and the airfoil portion 34. It is a region on the opposite side of the pressure surface 46 to the negative pressure surface 48 with the pressure surface 46 interposed in the code orthogonal direction. In addition, in a plan view (when viewed from the radial direction), the suction surface side region 104 is located between the suction surface 48 of the airfoil portion 34 at the connection position 35 and sandwiching the suction surface 48 in the direction perpendicular to the cord. It is the area opposite the pressure surface 46 .
As for the region ahead of the leading edge 42, a half straight line L1 extending from the trailing edge 44 toward the leading edge 42 in the chord direction with the leading edge 42 as a starting point is defined by the pressure side region 102 and the suction side region. Let it be the boundary of the region 104 . As for the area behind the trailing edge 44, a half straight line L2 extending from the trailing edge 44 toward the trailing edge 44 from the leading edge 42 in the cord direction is defined by the pressure side area 102 and the suction side area. Let it be the boundary of the region 104 .

In some embodiments, the second end 84 of the platform cooling passage 80 is located in the leading edge cavity 52 at the connection 35 between the platform 32 and the airfoil 34 in plan view, as shown, for example, in FIG. It is connected to a portion closer to the pressure surface 46 than the camber line Lc. Alternatively, in some embodiments, for example, as shown in FIG. 7, the platform cooling channel 80 extends across the above-described half line L1 in plan view.

In accordance with the above-described embodiments, a portion of the platform cooling channel 80 is connected to the portion of the leading edge cavity 52 facing the pressure surface 46 such that the second end 84 of the platform cooling channel 80 is connected to the pressure surface 46 of the platform 32 . It will be located in the pressure side area 102 . Therefore, the cooling medium flowing through the platform cooling channel can cool not only the suction side region 104 but also the pressure side region 102 of the platform, and the turbine blades 30 can be cooled more effectively.

In some embodiments, the platform cooling channel 80 includes a first suction side passage extending into a suction side region 104 of the platform 32 facing the suction side 48 and a suction side region 104 of the platform 32 facing the suction side 48 in plan view. a second suction side passage extending along the first suction side passage within 104 and connected to the first suction side passage via a third return portion. That is, the first suction surface side passage and the second suction surface side passage form a meandering flow path (serpentine flow path) within the suction surface side region 104 .

For example, in the exemplary embodiment shown in FIGS. 6 and 7, the platform cooling channels 80 are defined by suction side passages 86 (first suction side passages 86) extending into the suction side region 104 of the platform 32 in plan view. pressure surface side passage) and a suction surface side passage extending along the suction surface side passage 86 (first suction surface side passage) in the suction surface side region 104 and via a return portion 87 (third return portion). a suction side passage 88 (second suction side passage) connected to 86 (first suction side passage). That is, the suction surface side passage 86 (first suction surface side passage) and the suction surface side passage 88 (second suction surface side passage) form a meandering passage (serpentine passage) in the suction surface side region 104. ing.

6 and 7, the platform cooling passages 80 are, in plan view, suction side passages 88 (first suction side passages 88) that extend into the suction side region 104 of the platform 32. pressure surface side passage) and a suction surface side passage extending along the suction surface side passage 88 (first suction surface side passage) in the suction surface side region 104 and via a return portion 89 (third return portion). a suction side passage 90 (second suction side passage) connected to 88 (first suction side passage). That is, the suction surface side passage 88 (first suction surface side passage) and the suction surface side passage 90 (second suction surface side passage) form a meandering flow passage (serpentine flow passage) in the suction surface side region 104. ing.

According to the above-described embodiment, since the meandering flow path including the first suction side passage and the second suction side passage is formed in the suction side region 104 of the platform 32, the platform cooling in the suction side region 104 is The length of channel 80 can be increased. Therefore, the suction side area 104 of the platform 32 can be cooled more effectively.

In some embodiments, the platform cooling channel 80 includes, in plan view, a first pressure side passage extending into a pressure side region 102 of the platform 32 facing the pressure side 46 and a pressure side region 102 of the platform 32 facing the pressure side 46 . a second pressure side passage extending within 102 along the first pressure side passage and connected to the first pressure side passage via a fourth return. That is, the first pressure surface side passage and the second pressure surface side passage form a meandering flow path (serpentine flow path) within the pressure surface side region 102 .

For example, in the exemplary embodiment shown in FIG. 7, the platform cooling channels 80 are pressure side passages 92 (first pressure side passages) that extend into the pressure side region 102 of the platform 32 in plan view. ) and the pressure surface side passage 92 (the first pressure surface side passage) in the pressure surface side region 102 and extends along the pressure surface side passage 92 (the first pressure surface side passage) and returns to the pressure surface side passage 92 (the fourth and a pressure surface side passage 94 (second pressure surface side passage) connected to the first pressure surface side passage). That is, the pressure surface side passage 92 (first pressure surface side passage) and the pressure surface side passage 94 (second pressure surface side passage) form a meandering flow passage (serpentine flow passage) within the pressure surface side region 102. ing.

According to the above-described embodiments, a serpentine flow path is formed in the pressure side region 102 of the platform 32, including first pressure side passages and second pressure side passages, so that platform cooling in the pressure side region 102 is The length of channel 80 can be increased. Therefore, the pressure surface side region 102 of the platform 32 can be cooled more effectively.

The contents described in each of the above embodiments are understood as follows, for example.

(1) A turbine blade (30) according to at least one embodiment of the present invention,
an airfoil (34) extending in the height direction and having a pressure surface (46) and a suction surface (48) extending between a leading edge (42) and a trailing edge (44);
a plurality of cavities (52, 54, 56) each extending along the wing height direction within at least the airfoil;
said plurality of cavities including a leading edge side cavity (52), a pressure side cavity (54) and a suction side cavity (56) communicating with each other to form a serpentine flow path (50);
wherein the leading edge side cavity is positioned closest to the leading edge in the chord direction of the airfoil portion among the plurality of cavities;
The pressure side cavity is located on the trailing edge side of the leading edge side cavity in the chord direction, and through a first return portion (53) on the side of the base end (38) of the airfoil portion in the blade height direction. connected to the leading edge side cavity through
The suction side cavity is positioned so as to at least partially overlap the pressure side cavity on the trailing edge side of the leading edge side cavity in the chord direction, and the tip of the airfoil portion in the blade height direction ( 40) is connected to the pressure side cavity via the second return portion (55) on the side,
An exit hole (70) is formed at the leading edge of the airfoil and communicates with the leading edge cavity and opens to the surface of the airfoil at the leading edge.

According to the above configuration (1), the pressure side cavity and the suction side cavity, which form the meandering flow path through which the cooling medium flows, are separately provided and connected via the second return section. The cooling medium after passing through can flow into the pressure side cavity. Therefore, compared to cooling both the pressure side and the suction side of the airfoil with a single cavity, the airfoil includes the airfoil while preventing overcooling of the pressure side, which has a relatively small heat load. Turbine blades can be effectively cooled. In addition, since the pressure surface side cavity and the leading edge side cavity are connected via the first return portion and an exit hole communicating with the leading edge side cavity is provided, the cooling medium after passing through the pressure surface side cavity is returned to the first return portion. It can flow into the leading edge side cavity through the return portion and can be discharged to the outside of the turbine blade through the outlet hole.
That is, the cooling medium that has cooled the airfoil by flowing through the suction side cavity and the pressure side cavity is further supplied to the leading edge side cavity to cool the airfoil using the remaining cooling capacity. At the same time, the cooling medium whose temperature has been raised by cooling the airfoil portion can be discharged from the outlet hole and used for film cooling of the turbine blade. Therefore, according to the above embodiment (1), the cooling medium can be effectively used while cooling the pressure side and the suction side, which have different heat loads, in a well-balanced manner, and the amount of cooling medium supplied to the turbine blades is increased. can be suppressed.

(2) In some embodiments, in the configuration of (1) above,
Said airfoil (34) is not provided with holes connected to said pressure side cavity or said suction side cavity and opening to the surface of said airfoil.

According to the configuration (2) above, since there is no hole for discharging the cooling medium from the suction side cavity or the pressure side cavity to the outside of the turbine blade, the cooling medium supplied to the suction side cavity is not provided. can be led through the pressure side cavity to the leading edge side cavity. Therefore, after the temperature of the entire amount of the cooling medium supplied to the suction side cavity is sufficiently increased and the cooling capacity is fully used, the cooling medium can be discharged to the outside of the turbine blade through the outlet holes. . In this way, the cooling medium can be effectively used to effectively cool the turbine blades.

(3) In some embodiments, in the configuration of (1) or (2) above,
The turbine blade (30) is
The cooling medium supplied to the meandering flow path (50) is configured to be discharged to the outside of the turbine blade (30) only through the outlet hole (70).

According to the configuration (3) above, all of the cooling medium supplied to the meandering flow path is discharged to the outside of the turbine blade only through the outlet hole leading from the leading edge side cavity to the surface of the airfoil portion. That is, since all the cooling medium supplied to the suction side cavity is led to the leading edge side cavity via the pressure side cavity, the temperature of the total amount of cooling medium supplied to the suction side cavity is sufficiently high. to fully use the cooling capacity, the cooling medium can be discharged to the outside of the turbine blades through the exit holes. In this way, the cooling medium can be effectively used to effectively cool the turbine blades.

(4) In some embodiments, in the configuration of any one of (1) to (3) above,
The inner wall surface (96) of the pressure side cavity formed by the partition (58) between the pressure side cavity (54) and the suction side cavity (56) and the inner wall surface of the suction side cavity ( 98) increases in the chord direction as it approaches the trailing edge (44).

According to the configuration (4) above, the distance between the inner wall surfaces formed by the partition separating the pressure side cavity and the suction side cavity from each other increases as the trailing edge is approached in the cord direction. , the cross-sectional shapes of the pressure side cavity and the suction side cavity can be easily formed along the pressure side and the suction side. This makes it easier to reduce the wall thickness between the pressure surface and the pressure surface side cavity and the wall thickness between the suction surface side and the suction surface side cavity. The cooling medium can cool the turbine blades more effectively.

(5) In some embodiments, in the configuration of any one of (1) to (4) above,
The turbine blade (30) is
a platform (32) connected to the airfoil (34);
Platform cooling formed within said platform and having a first end (82) connected to said suction side cavity (56) and a second end (84) connected to said leading edge side cavity (54) a channel (80);
Prepare.

According to the configuration (5) above, since the platform cooling channel is formed inside the platform and has both ends connected to the suction side cavity and the leading edge side cavity, the suction side cavity (serpentine channel) is provided. A portion of the flowing cooling medium can be diverted and directed to the platform cooling channel, and the cooling medium that has passed through the platform cooling channel can join the leading edge side cavity (serpentine channel). Therefore, the platform can be cooled using part of the cooling medium supplied to the meandering flow path, and the turbine blades can be cooled more efficiently. After passing through the platform cooling flow path, the cooling medium merges with the leading edge side cavity and is discharged from the turbine blade through the outlet hole communicating with the leading edge side cavity. Therefore, the remaining cooling capacity of the cooling medium after cooling the platform can be used to cool the airfoil, and the cooling medium whose temperature has risen can be discharged from the exit hole and used for film cooling of the turbine blades. can. Therefore, according to the above configuration (5), it is possible to effectively use the cooling medium and more effectively suppress an increase in the amount of the cooling medium supplied to the turbine blades.

(6) In some embodiments, in the configuration of (5) above,
The second end (84) of the leading edge side cavity (54) is located above the camber line (Lc) at the connection position (35) between the platform (32) and the airfoil (34) in plan view. It is connected to the part on the side of the pressure surface (46).

According to the configuration (6) above, since the second end of the platform cooling channel is connected to the pressure surface side portion of the leading edge side cavity, a portion of the platform cooling channel extends to the pressure surface side region of the platform. will be located inside. Therefore, the cooling medium flowing through the platform cooling flow path can cool not only the suction surface side region but also the pressure surface side region of the platform, and the turbine blades can be cooled more effectively.

(7) In some embodiments, in the configuration of (5) or (6) above,
said platform cooling channel (80) comprising:
a first suction side passage (for example, a suction side passage 86) extending in a suction side region (104) of the platform (32) facing the suction side (48) in plan view;
A second suction surface extending along the first suction surface side passage within the suction surface side region and connected to the first suction surface side passage via a third return portion (for example, return portion 87) side passages (eg, suction side passages 88).

According to the above configuration (7), since the meandering flow path including the first suction side passage and the second suction side passage is formed in the suction side region of the platform, the platform cooling flow in the suction side region The length of the path can be lengthened. Therefore, the suction side area of the platform can be cooled more effectively.

(8) In some embodiments, in the configuration of any one of (5) to (7) above,
said platform cooling channel (80) comprising:
a first pressure side passageway (e.g., pressure side passageway 92) extending in plan view into a pressure side region (102) of said platform (32) facing said pressure side (46);
A second pressure surface extending along the first pressure surface side passage within the pressure surface side region and connected to the first pressure surface side passage via a fourth return portion (for example, return portion 93) side passages (eg, pressure side passages 94).

According to the above configuration (8), since the meandering flow path including the first pressure surface side passage and the second pressure surface side passage is formed in the pressure surface side region of the platform, the platform cooling flow in the pressure surface side region is The length of the path can be lengthened. Therefore, the pressure surface side region of the platform can be cooled more effectively.

(9) A gas turbine (1) according to at least one embodiment of the present invention,
a turbine blade (30) according to any one of (1) to (8) above;
a combustor (4) for producing combustion gas flowing through a combustion gas flow path provided with said turbine blades;
Prepare.

According to the above configuration (9), the pressure side cavity and the suction side cavity forming the meandering flow path through which the cooling medium flows are separately provided and connected via the second return section. The cooling medium after passing through can flow into the pressure side cavity. Therefore, compared to cooling both the pressure side and the suction side of the airfoil with a single cavity, the airfoil includes the airfoil while preventing overcooling of the pressure side, which has a relatively small heat load. Turbine blades can be effectively cooled. In addition, since the pressure surface side cavity and the leading edge side cavity are connected via the first return portion and an exit hole communicating with the leading edge side cavity is provided, the cooling medium after passing through the pressure surface side cavity is returned to the first return portion. It can flow into the leading edge side cavity via the return portion and can be discharged from the outlet hole.
That is, the cooling medium that has cooled the airfoil by flowing through the suction side cavity and the pressure side cavity is further supplied to the leading edge side cavity to cool the airfoil using the remaining cooling capacity. At the same time, the cooling medium whose temperature has been raised by cooling the airfoil portion can be discharged from the outlet hole and used for film cooling of the turbine blade. Therefore, according to the above embodiment (9), the cooling medium can be effectively utilized while cooling the pressure side and the suction side, which have different heat loads, in a well-balanced manner, and the amount of cooling medium supplied to the turbine blades is increased. can be suppressed.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes modifications of the above-described embodiments and modes in which these modes are combined as appropriate.

As used herein, expressions such as "in a certain direction", "along a certain direction", "parallel", "perpendicular", "center", "concentric" or "coaxial", etc. express relative or absolute arrangements. represents not only such arrangement strictly, but also the state of being relatively displaced with a tolerance or an angle or distance to the extent that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous", which express that things are in the same state, not only express the state of being strictly equal, but also have tolerances or differences to the extent that the same function can be obtained. It shall also represent the existing state.
Further, in this specification, expressions representing shapes such as a quadrilateral shape and a cylindrical shape not only represent shapes such as a quadrilateral shape and a cylindrical shape in a geometrically strict sense, but also within the range in which the same effect can be obtained. , a shape including an uneven portion, a chamfered portion, and the like.
Moreover, in this specification, the expressions “comprising”, “including”, or “having” one component are not exclusive expressions excluding the presence of other components.

1 gas turbine 2 compressor 4 combustor 6 turbine 8 rotor 10 compressor casing 12 air intake 16 stationary blade 18 rotor blade 20 casing 22 turbine casing 24 stator blade 26 rotor blade 28 combustion gas flow path 29 exhaust chamber 30 turbine blade 32 Platform 34 Airfoil 34a Inner wall 34b Surface 35 Connection point 36 Blade root 37 Engagement 38 Base end 40 Tip 41 Tip 42 Leading edge 43 Leading edge 44 Trailing edge 45 Trailing edge 46 Pressure surface 48 Suction surface 50 meandering channel 51 inlet opening 52 leading edge cavity 53 first return portion 54 pressure side cavity 55 second return portion 56 negative pressure side cavity 58 partition wall 60 meandering channel 61 inlet opening 62 cavity 63 return portion 64 cavity 65 return portion 66 cavity 68 exit hole 69 exit hole 70 exit hole 72 leading edge exit hole 74 tip exit holes 76a-76d rib 80 platform cooling channel 82 first end 84 second end 86 suction side passage 87 return portion 88 suction side passage 89 Return portion 90 Suction surface side passage 92 Pressure surface side passage 93 Return portion 94 Pressure surface side passage 96 Inner wall surface 98 Inner wall surface 102 Pressure surface side region 104 Suction surface side region

Claims (9)

an airfoil extending in the wing-height direction and having a base end and a tip, which are opposite ends in the wing-height direction, and a pressure surface and a suction surface extending between a leading edge and a trailing edge;
a plurality of cavities each extending along the airfoil height direction at least inside the airfoil;
the plurality of cavities include a leading edge side cavity, a pressure side cavity, and a suction side cavity that communicate with each other to form a meandering flow path;
wherein the leading edge side cavity is positioned closest to the leading edge in the chord direction of the airfoil portion among the plurality of cavities;
The pressure side cavity is located on the trailing edge side of the leading edge side cavity in the chord direction, and is connected to the leading edge side cavity via a first return portion on the base side of the airfoil portion in the blade height direction. connected and
The suction side cavity is positioned so as to at least partially overlap with the pressure side cavity on the trailing edge side of the leading edge side cavity in the chord direction, and on the tip side of the airfoil portion in the blade height direction. is connected to the pressure side cavity via the second return part of
A turbine blade comprising an exit hole formed in a leading edge of said airfoil communicating with said leading edge side cavity and opening to a surface of said airfoil at said leading edge. 2. The turbine blade according to claim 1, wherein the airfoil is free of holes connected to the pressure side cavity or the suction side cavity and opening to the surface of the airfoil. 3. The turbine blade according to claim 1, wherein the cooling medium supplied to said meandering flow path is discharged to the outside of said turbine blade only through said exit hole. The distance in the camber orthogonal direction between the inner wall surface of the pressure side cavity and the inner wall surface of the suction side cavity formed by the partition wall between the pressure side cavity and the suction side cavity is the cord direction. 4. The turbine blade according to any one of claims 1 to 3, wherein the width increases toward the trailing edge at. a platform connected to the airfoil;
a platform cooling channel formed within the platform and having a first end connected to the suction side cavity and a second end connected to the leading edge side cavity;
The turbine blade according to any one of claims 1 to 4, comprising: The turbine blade according to claim 5, wherein the second end is connected to a portion of the leading edge side cavity that is closer to the pressure surface than the camber line at the connection position between the platform and the airfoil portion in plan view. The platform cooling channel comprises:
a first suction surface side passage extending in a suction surface side region of the platform facing the suction surface in plan view;
a second suction side passage extending along the first suction side passage within the suction side region and connected to the first suction side passage via a third return portion. A turbine blade according to claim 5 or 6. The platform cooling channel comprises:
a first pressure side passage extending in a pressure side region of the platform facing the pressure side in plan view;
a second pressure surface side passage extending along the first pressure surface side passage within the pressure surface side region and connected to the first pressure surface side passage via a fourth return portion. A turbine blade according to any one of claims 5 to 7. a turbine blade according to any one of claims 1 to 8;
a combustor for generating combustion gas flowing through a combustion gas flow path provided with the turbine blades;
A gas turbine with a

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