JP7019331B2 - Turbine bucket cooling - Google Patents

Description

Embodiments of the present invention generally relate to rotary machines, and more specifically to cooling at least a portion of a turbine bucket.

As is known in the art, gas turbines use a row of wheel / disk buckets in a rotor assembly, the bucket rows alternating with a row of stationary vanes in a stator or nozzle assembly. These alternating rows extend axially along the rotor and stator, and the combustion gas can rotate the rotor as the combustion gas flows through these rows.

Axial / radial openings at the boundary between the rotating bucket and the stationary nozzle can cause hot combustion gas to exit the hot gas passage and enter the wheel space between the bucket rows radially. .. To limit such ingress of hot gas, the bucket structure typically has an axially protruding angel wing that works with a blocking member that extends axially from an adjacent stator or nozzle. Use. These angel wings and blocking members overlap but do not contact and serve to limit the entry of hot gas into the wheel space.

In addition, cooling air or "purge air" is often introduced into the wheel space between the bucket rows. This purged air cools the wheel space and other areas within the radial inside of the bucket and serves to provide countercurrent of cooling air to further limit the ingress of hot gas into the wheel space. Fulfill. Therefore, the angel wing seal is further designed to limit the leakage of purged air into the hot gas flow path.

Nevertheless, in most gas turbines it has been shown that a significant amount of purged air leaks into the hot gas flow path. For example, in the first and second stage wheel spaces, this purge air leak can be between 0.1% and 0.3%. The resulting mixing of cold purge air and hot gas flow results in large mixing losses due to differences in flow direction or swirl as well as differences in temperature between purged air and hot gas.

In addition, the mixing of purged air and hot gas flow makes the gas flow across the turbine bucket platform more disordered. When the chaotic gas flow increases, the platform is not heated equally during turbine operation, which is accompanied by an increase in the thermal stress of the platform, resulting in a shorter service life of the turbine bucket.

U.S. Patent Application Publication No. 2014/0234076

In one embodiment, the invention provides a method of cooling at least a portion of a turbine bucket. The method comprises changing the swirling speed of the purged air below the platform lip extending axially from the platform during operation of the turbine. Here, changing the swirling speed of the purge air causes a plurality of voids arranged along the length of the angel wing extending axially from the surface of the shank portion of the turbine bucket to interrupt the flow of the purge air. Including that.

These and other features of the invention will be more easily understood by describing in detail the various aspects of the invention below in connection with the accompanying drawings showing the various embodiments of the invention. There will be.

It is a schematic sectional drawing of a part of a known turbine. It is a perspective view of a known turbine bucket. It is a figure which looked at the part of the turbine bucket suitable for use by embodiment of this invention in the axial direction. It is a schematic diagram of a turbulator suitable for use by various embodiments of this invention. It is a perspective view of the heating state at the time of operation of a known turbine. It is a perspective view of the heating state at the time of operation of the turbine bucket by embodiment of this invention. It is a schematic diagram of a turbulator suitable for use by various embodiments of this invention. It is a schematic diagram of a turbulator suitable for use by various embodiments of this invention. It is a schematic diagram of a turbulator suitable for use by various embodiments of this invention. It is a schematic diagram of a turbulator suitable for use by various embodiments of this invention. FIG. 3 is an axial view of a portion of a turbine bucket suitable for use according to another embodiment of the present invention. It is a perspective view of the part of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the part of the turbine bucket suitable for use by still another embodiment of this invention. FIG. 6 is a schematic diagram of the flow of purged air associated with a typical turbine bucket. It is the schematic of the flow of the purge air related to the turbine bucket by embodiment of this invention. It is a side sectional view of a part of the turbine bucket suitable for use by embodiment of this invention. It is a perspective view of the part of the turbine bucket of FIG. FIG. 3 is a perspective view of a portion of a turbine bucket suitable for use according to another embodiment of the present invention. FIG. 3 is a perspective view of a portion of a turbine bucket suitable for use according to yet another embodiment of the present invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of the turbine bucket suitable for use by still another embodiment of this invention. It is a perspective view of a part of the turbine bucket suitable for use by embodiment of this invention. It is a figure which looked at the part of the turbine bucket of FIG. 27 inward in the radial direction. FIG. 3 is a perspective view of a portion of a turbine bucket suitable for use according to another embodiment of the present invention. FIG. 3 is a perspective view of a portion of a turbine bucket suitable for use according to yet another embodiment of the present invention. It is a side sectional view of the turbine bucket of FIG. It is a perspective view of a part of the turbine bucket by embodiment of this invention. It is a figure which looked at the part of the turbine bucket of FIG. 32 inward in the axial direction. FIG. 32 is a view of a part of the turbine bucket of FIG. 32 viewed downward in the radial direction.

It should be noted that the drawings of the present invention are not proportional to the actual size. The drawings are intended only to show the typical aspects of the invention and should therefore not be considered as limiting the scope of the invention. In drawings, similar numbers represent similar elements between drawings.

Next, referring to the drawings, FIG. 1 is a schematic cross-sectional view of a part of the gas turbine 10 including the bucket 40 arranged between the first stage nozzle 20 and the second stage nozzle 22. As those skilled in the art will understand, the bucket 40 extends radially outward from a rotor (not shown) extending axially. The bucket 40 includes a substantially planar platform 42, an aero foil extending radially outward from the platform 42, and a shank portion 60 extending radially inward from the platform 42.

The shank portion 60 includes a pair of angel wing seals 70 and 72 extending outward in the axial direction toward the first stage nozzle 20, and an angel wing seal extending outward in the axial direction toward the second stage nozzle 22. Includes 74 and. It should be understood that different numbers and arrangements of angel wing seals are possible and they are within the scope of the present invention. The numbers and arrangements of angel wing seals described herein are presented for illustration purposes only.

As can be seen in FIG. 1, the nozzle surface 30 and the blocking member 32 extend axially from the first stage nozzle 20 and are arranged radially outside the angel wing seals 70 and 72, respectively. Therefore, the nozzle surface 30 overlaps with the angel wing seal 70 but does not come into contact with it, and the blocking member 32 overlaps with the angel wing seal 72 but does not come into contact with it. Similar arrangements are shown for the blocking member 32 of the second stage nozzle 22 and the angel wing seal 74. In the arrangement shown in FIG. 1, a certain amount of purged air is discharged between, for example, the nozzle surface 30, the angel wing seal 70, and the platform lip 44 during the operation of the turbine, thereby causing a high temperature gas flow path. Both the leakage of purged air into the 28 and the intrusion of the hot gas from the hot gas flow path 28 into the wheel space 26 can be restricted.

As shown in FIG. 1, each of the nozzle surface 30 and the blocking member 32 acts to limit the leakage of purged air and the ingress of hot gas. In another embodiment of the present invention, a separate blocking member similar to the blocking member 32 may be provided between the angel wing seal 70 and the nozzle surface 30 to provide such a function.

FIG. 1 shows that the bucket 40 is located between the first stage nozzle 20 and the second stage nozzle 22 so that the bucket 40 represents the first stage bucket, which is merely exemplary and explanatory. Because of. The principles and embodiments of the invention described herein can be expected to be applied to buckets at any stage of the turbine to achieve similar results.

FIG. 2 is a perspective view of a part of the bucket 40. As shown, the aerofoil 50 includes a leading edge 52 and a trailing edge 54. The shank portion 60 includes a surface 62 located closer to the leading edge 52 than the trailing edge 54 and located between the angel wing 70 and the platform lip 44.

FIG. 3 is a schematic view of the bucket 40 viewed axially toward the surface 62. As shown, the bucket 40 includes a plurality of turbulators 110, which are axially outward from the surface 62 and / or from the radial inner surface 46 of the platform lip 44, as described in more detail below. It can extend inward in the radial direction. Also, as described in more detail below, the turbulator can be of any shape and orientation.

For example, FIG. 4 is a detailed view of a lip having a turbulator 110, wherein the turbulator 110 has a first concave surface 114 and a first concave surface 114 that open in the direction R of the bucket 40 (FIG. 3) to be rotated. Includes a second convex surface 116 on the opposite side of the, as well as a radial inner surface 118 between the first concave surface 114 and the second convex surface 116. These surfaces 114, 116, 118 form the body 112 of each turbulator 110. In the embodiment of FIG. 4, each turbulator 110 forms a ribbed member extending radially inward from the radial inner surface 46 of the platform lip 44. In another embodiment of the invention, the turbulator can be separated from the radial inner surface 46 of the platform lip 44 and extend axially outward from the surface 62 (FIG. 3). In other embodiments, the turbulator can be attached to either or both of the radial inner surfaces 46 of the platform lip 44 and the surface 62 of the shank 60. In either case, the turbulator 110 may be axially angled so that, for example, the first concave surface 114 extends from the surface 62 at a positive or negative angle with respect to the longitudinal axis of the turbine. Can be attached. Embodiments of the invention using an axially angled turbulator are typically one or one that is angled ± 70 degrees with respect to the longitudinal axis of the turbine when mounted. Includes multiple turbines.

The turbulator 110 draws in purged air and increases its swirling speed. Generally, the circumferential velocity of the purge air coming from the wheel space cavity is 0.2-0.4 times the local circumferential velocity of the adjacent rotor surface. The turbulator according to the embodiment of the present invention increases the circumferential velocity by 0.9 to 1.1 times by applying a force to the purge flow passing through the turbulator. This results in a slight torque loss, but as this flow passes through the main bucket 40, it regains a much larger and favorable torque force, resulting in a net gain of efficiency of approximately 0.5% in the turbine stage. .. This gain increases the circumferential swirling speed of the purged air, creating a curtain effect that prevents hot gas from being taken into the wheel space cavity and in the turbine main flow path, further described below. It is the result of both changes in the circumferential angle of the incoming purge air. This change in circumferential angle allows the purged air to better match the direction of the hot gas flow, resulting in the purged air leaking from the wheel space 26 (FIG. 1) to the hot gas flow path 28 (FIG. 1). When the mixing loss is significantly reduced.

Such a better match between the purged air and the hot gas flow reduces the flow instability of the shear layer of the flow and reduces the circumferentially alternating low and high pressure portions across the opening of the wheel space 26. As a result, the uptake of hot gas is reduced and the film of cold purge air entering the main flow path 28 is more evenly distributed across the platform 42 (FIG. 1). This film forms a shield between the hot gas and the metal surface of the platform 42. This reduces the "hotspots" of the entire platform 42. Such reductions in hotspots can include reductions in hotspot size, number, temperature, or all three. As described in more detail below, this reduction lowers the temperature of the entire platform 42, cools the platform 42, platform lip 44, shank surface 62, and aerofoil 50, and heats the platform 42 more uniformly. The Rukoto. This reduces the stress generated by the thermal gradient, thereby extending the life of the components and lowering the cooling conditions of the platform 42 during operation.

5 and 6 are in-operation perspective views of the bucket 40 with and without the turbulator according to the embodiment of the present invention, respectively. In FIGS. 5 and 6, the aerofoil 50 and the platform 42 are shown separately for brevity only. In FIG. 5, multiple hotspots 43A, 43B, 43C, 43D are seen along platform 42 as a result of chaotic or unreduced mixing of purged air and hot gas currents, which are known equipment and. The method is typical. Similar hotspots 53A, 53B, 53C are found along the aerofoil 50, which generally extend upward from the platform 42 to about 20% of the total length of the aerofoil 50. These hotspots 43A, 43B, 43C, 43D, 53A, 53B, 53C can reach temperatures above 1700 ° F, covering most of the surface area of the platform 42 and 20% proximal to the aerofil 50. May cover. Moreover, the temperature difference between these hotspots 43A, 43B, 43C, 43D, 53A, 53B, 53C and the platform 42 and other parts of the aerofoil 50 can be greater than 600 ° F. In FIG. 6, when the mixture of purged air and hot gas stream is reduced according to embodiments of the present invention, a film of cold purge gas is more evenly distributed across the platform 42, thereby making the platform 42 more uniform. Cooling 45 is performed, and the aero foil 50 is cooled 55 more uniformly. Nonetheless, there is a temperature difference across the platform 42 and the proximal portion of the aero foil 50, but the larger portion of the surface area of the platform 42 and the aero foil 50 are at lower temperatures and the temperature difference is significant over these surfaces. It will be reduced. In some cases, the recorded minimum temperature drops from about 1400 ° F (FIG. 5) to about 1300 ° F (FIG. 6), and the recorded maximum temperature drops from about 2000 ° F (FIG. 5). It dropped to 1800 ° F (Fig. 6). The platform lip 44 and the shank surface 62 also showed some improvement in cooling.

Moreover, the larger parts of these surfaces have lower temperatures, which lowers the average temperature of the entire surface. When the platform 42 and the aero foil 50 are heated more uniformly in this way 45, 55, respectively, the thermal stresses on these components are reduced, thereby extending their service life.

The concave turbulator of FIG. 4 is only one embodiment capable of reducing the mixing loss of the purged air and the hot gas flow. For example, FIGS. 7-10 show turbulators with different configurations. In FIG. 7, the first and second surfaces 214 and 216 are substantially straight, and the radial inner side surface 218 is substantially perpendicular to both the first and second surfaces 214 and 216. As a result, the cross section of the main body 212 is substantially rectangular. In other embodiments, the rectangular protrusion can be angled with respect to a radial or axial plane. In FIG. 8, each of the first and second surfaces 314 and 316 is substantially straight, but at an angle that is not perpendicular to the radial direction, so that the body 312 has wider dimensions inside the radial direction. Has a substantially trapezoidal cross-sectional shape. On the other hand, in FIG. 9, the first and second surfaces 414 and 416 have angles that are not perpendicular to the radial direction, so that the body 412 has a substantially trapezoidal cross section with narrower radial inside dimensions. Has a shape. In FIG. 10, each turbulator 510 is formed by crossing a radial inner surface 518 and at least one adjacent bow-shaped surface 514 and 516 arranged on both sides of the radial inner surface 518. The end faces 515 and 517 are substantially straight and extend radially from the platform lip 44, thereby sandwiching the plurality of turbulators 510.

As described above, the turbulator according to the embodiment of the present invention can extend axially outward from the surface 62 and / or radially inward from the radial inner surface 46 of the platform lip 44. When the turbulator extends axially outward from the surface 62, the closer the turbulator is to the radial inner surface 46 of the platform lip 44, the greater the improvement in turbine efficiency. That is, moving the turbulator radially inward from the inner surface 46 of the platform lip 44 and away from it reduces the gain in efficiency. As will be described in more detail below with reference to FIGS. 14 and 15, this effect is due to: That is, the combination of the platform lip 44 and the turbulator allows the purge air to be thrown at maximum speed so as to be axially separated from the shank surface 62, which prevents hot gas from being trapped into the wheel space cavity. Creates a curtain effect and reduces the intrusion of hot gas into the wheel space 26 (FIG. 1). As the space between the turbulator and the platform lip 44 increases, this curtain effect caused by it gradually diminishes.

FIG. 11 is a view of a part of the bucket 40 viewed in the axial direction toward the surface 62. As can be seen in FIG. 11, each of the plurality of turbulators 610 is axially angled so that at least the first concave surface 614 of each turbulator 610 is not perpendicular to the surface 62. As described above, in such an embodiment, the swirling angle of the purge air can be changed.

12 and 13 are perspective views of a portion of the turbine bucket according to still another embodiment of the present invention. In FIG. 12, a plurality of turbulators 710 are formed from additional material extending radially inward from the platform lip 44 (eg, machining, casting, etc.). Typically, such additional material is included in the platform lip 44 during casting, after which the casting material is machined to form the turbulator 710. In another embodiment of the invention, the turbulator can be provided on another material that is welded, fastened, or otherwise secured to the platform lip 44. The turbulator can be in contact with the surface 62 or can be arranged axially spaced from the surface 62. For example, in FIG. 13, the turbulator 810 also extends radially inward from the platform lip 44, but is axially spaced from the curved surface 62 in the illustrated embodiment. There is. These protrusions of the turbulator can be angled with respect to the radial and / or axial planes.

The turbulators 710 and 810 shown in FIGS. 12 and 13, respectively, are shown to have a substantially rectangular cross-sectional shape, which is neither necessary nor important. Such a turbulator can be, for example, any cross-sectional shape including the shapes described above for FIGS. 4 and 7-10. Similarly, any such turbulator can be axially angled, as described above for FIG.

14 and 15, respectively, are views schematically showing the flow of purge gas in a known gas turbine and a gas turbine including a turbulator according to an embodiment of the present invention. FIG. 14 shows purged air 80, whose axial momentum is small and its reach is limited to area 82, where the purged air 80 forms a vortex and ultimately. It leaks into the high temperature gas flow path 28. The concentrated portion of the purge air 80 is thrown axially from the blade shank surface by the same curvature of the blade shank surface facing the area 82, but only at a distance close to the surface 62, so that the hot gas 95 Allows to enter the wheel space 26.

In contrast, FIG. 15 shows the effect of turbulators 110-810 on purged air 80 by various embodiments of the invention. As can be seen in FIG. 15, the area 83 into which the purge air is thrown with higher axial momentum / velocity is at a greater distance from the surface 62. In addition, this area 83 of purged air has moved axially away from the surface 62 as compared to FIG. At the same time, any leaking purge air 85 was moved towards the nozzle 30 away from the platform lip 44 (FIGS. 12-13). This effectively creates a curtain effect, limiting the ingress of the hot gas 95 from the hot gas flow path 28 and finally limiting the leakage from the wheel space 26 into the hot gas flow path 28. Therefore, these embodiments presented herein enhance the curtain / seal effectiveness and, when implemented, have the same / higher sealing effect against the uptake of hot gas into the wheel space cavity. The condition of the purge flow rate can be lowered while maintaining the condition.

Further, as a result of the reduced amount of hot gas taken in, further components in the vicinity of the wheel space 26 including the nozzle surface 30 are cooled. Typically, in embodiments of the invention it has been shown that the nozzle surface 30 is cooled by 100 ° F to 400 ° F.

The increase in turbine efficiency achieved using embodiments of the present invention can be due to several factors. First, as described above, the mixing loss caused by the purged air is reduced by increasing the swirling speed of the purged air into the high temperature gas flow path 28. Further, the curtain effect caused by the turbulator according to the present invention reduces or prevents the ingress of the hot gas 95 into the wheel space 26, and the wheel space cavity is taken in by little or no hot gas. Prevents heating. Each of these factors contributes to the observed increase in efficiency.

In addition, the total amount of purged air required is reduced for at least two reasons. First, reducing the amount of leaked purge air inevitably reduces the amount of purge air that must replace it, which has a direct positive effect on turbine efficiency. Secondly, when the intrusion of the high temperature gas 95 into the wheel space 26 is reduced, the temperature rise in the wheel space 26 becomes small, and further, additional purge air is introduced in association with the temperature rise to increase the temperature. The need to lower is reduced. Each of these reductions in the overall purge air required reduces the demand on other system components such as the compressor from which the purge air is supplied.

Lower temperatures of the bucket platform 42, platform lip 44, and bucket shank surface, and more uniform distribution of the cold purge gas film across the platform 42 can also be achieved by other embodiments. can. For example, FIG. 16 is a side sectional view of a part of the turbine bucket 40 according to the embodiment of the present invention. As can be seen in FIG. 16, the distal end 148 of the platform lip 144 is angularly outwardly angled towards the aerofoil 50.

FIG. 17 is a perspective view of the bucket 40 of FIG. A plurality of voids 110 are provided along the distal end 148 of the platform lip 144. As shown in FIG. 17, the shape of the vacant space 110 is substantially trapezoidal, which is neither necessary nor important. For example, voids with other shapes, including rectangles, rhomboids, or bows can also be used.

For example, FIG. 18 is a perspective view of the bucket 40 according to another embodiment of the present invention. Here, the platform lip 144 extends axially from the platform 42 (ie, the distal end is not angled towards the aerofoil 50 as in FIGS. 16 and 17). The vacant space 210 extends through the platform lip 144 into the bow passage, so that the rest of the platform lip 144 adjacent to the vacant space 210 includes the bow-shaped surface 145.

The embodiment of the present invention shown in FIG. 19 shows a perspective view of the bucket 40. Here, the platform lip 144 includes an angled distal end 148, as in FIGS. 16 and 17. However, the void 310 is formed in the body 146 rather than the distal end 148 of the platform lip 144. As described above, the space 310 can take any shape including, for example, a rectangle, a trapezoid, a rhomboid, an arch, and the like.

20-22 are perspective views of another embodiment of the present invention. In FIG. 20, the shape of the void 410 is elliptical and is angled with respect to the radial axis of the bucket 40.

In FIG. 21, elliptical voids 510 of different dimensions are used, the dimensions of the voids increase along the platform lip 144 from the end closer to the concave posterior surface of the aerofoil 50 towards the convex anterior surface. .. In such an embodiment, the effect of the void 510 on the purge air between the platform lip 144 and the angel wing 70 is generally greater as it is adjacent to the larger void. This is done, for example, for a variety of reasons, for example, to allow the platform 42 to have a more uniform cooling by pushing a cooler purge stream onto the expected hotspot location on the platform 42. It may be desirable if it is necessary to control the amount of purge flow that covers and passes circumferentially.

In FIG. 22, elliptical voids 510 of different dimensions are used, the dimensions of the void shrink along the platform lip 144 from the end closer to the concave posterior surface of the aerofoil 50 towards the convex anterior surface. .. As should be recognized from the above considerations, such embodiments are desirable when, for example, larger vacant areas have greater loss of purged air or intrusion of hot gas.

23-26 are perspective views of the turbine bucket 40 according to various embodiments of the present invention. In each of the embodiments of FIGS. 23-26, the voids are arranged non-uniformly along the platform lip 144.

In FIG. 23, a plurality of substantially rectangular voids 610 are placed along the platform lip 144, which is closer to the convex anterior surface, rather than the concave posterior surface of the aerofoil 50.

In FIG. 24, the areas where the vacant spaces are concentrated are opposite to those in FIG. 23, and the substantially rectangular vacant spaces 610 are platforms that are closer to the concave rear surface rather than the convex front surface of the aerofoil 50. Arranged along the lip 144.

25 and 26 show embodiments similar to FIGS. 23 and 24, respectively, in which the void 710 is a cut in the material removed from the edge of the platform lip 144 (FIG. 22). The use of the vacant space 710 at the edge of the platform lip 144 can be used, for example, to direct purge air toward either the convex front surface or the concave rear surface of the aero foil 50.

More uniform distribution of the cold purge gas film across the platform 42 can also be achieved by yet other embodiments. For example, FIG. 27 is a perspective view of a part of the turbine bucket 40 according to the embodiment of the present invention. As can be seen in FIG. 27, a plurality of voids 910 are arranged along the angel wing rim 174 at the distal end 178 of the angel wing 170. The vacant spaces 910 are spaced apart along the angel wing rim 174 so that the rest of the angel wing rim 174 forms a plurality of columnar members 175. As shown in FIG. 27, the vacant space 910 is angled in the radial direction, i.e., angled with respect to the radial axis (Ar) of the turbine bucket 40, which is necessary. Nor is it important. In another embodiment of the invention, the void can be substantially parallel to the radial axis of the turbine bucket.

As most clearly shown in FIG. 28, which is a radial inward view of the turbine bucket 40, the columnar member 175 (and the corresponding void 910) includes an arcuate surface. Specifically, the columnar member 175 includes a concave surface 175A (convex surface of the vacant space 910) and a convex surface 175B (concave surface of the vacant space 910). Thus, the void 910 includes a first opening 910A along the axial inner surface 174A of the angel wing rim 174, and the first opening 910A is a second opening along the axial outer surface 174B of the angel wing rim 174. It is arranged on the side of the 910B. Of course, it should be understood that columnar members and voids can have other shapes. For example, columnar members and voids can have a rectangular, trapezoidal, or any other cross-sectional shape.

FIG. 29 is a perspective view of a part of the turbine bucket 40 according to another embodiment of the present invention. Here, the plurality of dam members 277 adjacent to the radial outer surface of the angel wing seal extend axially from the shank portion 60 to each of the plurality of columnar members 275. According to some embodiments, the dam member 277 can be angled with respect to the radial axis of the turbine bucket 40, i.e., positively or negatively with respect to the rotational direction of the turbine bucket 40. Can be angled. Similarly, according to some embodiments, the dam member 277 can include one or more arcuate surfaces, such as the columnar member 275, or, as described above, its cross section is rectangular. , Trapezoid, or any other shape.

FIG. 30 is a perspective view of a part of the turbine bucket 40 according to another embodiment of the present invention. Here, the seamless angel wing rim 374 extends upward from the angel wing seal 370, and the plurality of dam members 377 leave a gap 64 adjacent to the surface 62 without contacting the surface 62, and the rim 374 It extends axially from the surface 62 toward the surface 62.

FIG. 31 is a side sectional view of the turbine bucket 40 of FIG. 30 regarding the nozzle surface 130 according to the embodiment of the present invention. In FIG. 31, the nozzle surface 130 comprises or includes at least a porous or wearable portion along a radial inward surface, as the angel wing rim 374 cuts or digs a groove 131 in the nozzle surface 130. .. The porous or wearable portion shall comprise a "honeycomb" or similar pattern of nozzle surface 130 material so that the porous or wearable portion of the nozzle surface 130 is worn or worn by the angel wing rim 374. Can be done. In another embodiment of the invention, the porous or wearable portion is other than the nozzle surface 130 so that the porous or wearable portion of the nozzle surface 130 is also worn or worn by the angel wing rim 374. Can include or contain a softer material than the material of.

During operation, the purge air passes through the groove 131 of the nozzle surface 130, then flows downward between the dam members 377, and heads toward the surface 62. The purged air 80 then flows circumferentially through the gap 64 adjacent to the surface 62 as the turbine bucket 40 rotates, thereby increasing the swirling of the purged air 80.

As will be apparent from the above description, other modifications to the angel wing can be used to reduce the mixing between the purged air and the hot gas stream and to distribute the hot gas stream more evenly across the platform 42. For example, FIG. 32 is a perspective view of a part of the turbine bucket 40 according to the embodiment of the present invention. As can be seen in FIG. 32, a plurality of voids 1110 extend radially through the Angel Wing 470. As shown in FIG. 32, the plurality of voids 1110 are arranged axially inward along the angel wing 470 so as to be closer to the surface 62 than the angel wing rim 474. Each of the vacant spaces 1110 is shown in FIG. 32 as having a rectangular cross-sectional shape (ie, rectangular when viewed inward in the radial direction), which is not necessary or important. not. Any cross-sectional shape can be used, as will be appreciated by those skilled in the art, which is within the scope of the present invention.

As shown in FIG. 32, the plurality of voids 1110 are arranged substantially uniformly along the length of the angel wing 470. However, keep in mind that this is neither necessary nor important. According to another embodiment of the invention, there are more than one void at one end of the angel wing 470 than at the other end, more towards the center of the angel wing 470, or any other configuration. The vacant space 1110 can be arranged non-uniformly along the length of the angel wing 470.

FIG. 33 is a cross-sectional view of a part of the turbine bucket 40 passing through the angel wing 470 as viewed inward in the axial direction. As can be seen in FIG. 33, according to embodiments of the invention, the void 1110 comprises a convex surface 1112 and a concave surface 1114, which form a curved or bowed passage through the Angel Wing 470. That is, the void 1110 follows a path from the radial outward opening 1110A to the radial inward opening 1110B along the convex 1112 and the concave 1114. Thereby, the radial inward opening 1110B is placed closer to the end 470A of the angel wing 470 than the radial outward opening 1110A.

This curved or bowed shape of the void 1110 through the angel wing 470 increases the swirling speed of the purge air between the angel wing end 470 and the platform lip 44. As described above according to another embodiment of the invention, this creates a curtain effect, which limits the ingress of hot gas into the wheel space 26 (FIG. 1) and at the same time leaks out of the wheel space 26. The amount of purged air is reduced.

FIG. 34 is a view of a part of the turbine bucket 40 viewed downward in the radial direction. The concave surface 1114 of each vacant space 1110 can be seen. Further, as shown in FIG. 32, the concave surface 1114 is also axially angled. That is, the concave surface 1114 is angled with respect to both the longitudinal axis RL and the rotational direction R of the turbine bucket 40. Thus, the shape of the void 1110 so that it passes radially outward through the angel wing 470 gives the purge gas a swirl, the purge gas axially towards the angel wing rim 474, and the end of the angel wing 470. It is directed in both lateral directions toward the portion 470A.

The present invention is disclosed herein with examples including the best embodiments, including the fabrication and use of any device or system, and the implementation of any related or incorporated method. Allows the practice of the present invention. The patentable scope of the invention is defined by the claims and may include other examples conceived by those skilled in the art. Other such examples are within the scope of the claim if they have components that are not different from the wording of the claims, or if they contain equivalent components that are not substantially different from the wording of the claims. It is intended to be.

10 Gas turbine 20 1st stage nozzle 22 2nd stage nozzle 26 Wheel space 28 Flow path 30 Nozzle surface 32 Blocking member 40 Turbine bucket 42 Platform 43A Hotspot 43B Hotspot 43C Hotspot 43D Hotspot 44 Platform lip 45 More uniform Cooling, more uniform heating 46 Radial inner surface 48 Distal end 50 Aerofoil 52 Front edge 53A Hotspot 53B Hotspot 53C Hotspot 54 Trailing edge 55 More uniform cooling, more uniform heating 60 Shank part 62 Shank surface 64 Gap 70 Angel wing 72 Angel wing 74 Angel wing seal 80 Purge air 82 Area 83 Area 85 Leaking purge air 95 High temperature gas 110 Turbine, vacant space 112 Main body 114 Concave surface 116 Convex surface 118 Radial inner surface 130 Nozzle surface 131 Groove 144 Platform Lip 145 Arched Face 146 Body 148 Disdistant End 170 Angel Wing 174 Angel Wing Rim 174A Inner Side 174B Outer Side 175 Columnar Member 175A Concave 175B Convex 178 distal End 210 Turbine Radius, Empty 212 Inner side 275 Columnar member 277 Dam member 310 Turbine, vacant space 312 Main body 314 surface 316 surface 370 Angel wing seal 374 Angel wing rim 377 Dam member 410 Turbine member, vacant space 412 Main body 414 surface 416 surface 470 Angel wing 470 Rim 510 Turbine, Vacancy 514 Bow Face 515 End Face 516 Bow Face 517 End Face 518 Radial Inner Side 610 Turbine, Vacancy 614 Concave Surface 710 Turbine, Vacancy 810 Turbine Turbine 910 Vacancy 910 B 1st Opening 910 Place 1110A Outward opening 1110B Inward opening 1114 Concave 1112 Convex

Claims (6)

A method of cooling at least a part of the turbine bucket (40), wherein the method is:
During the operation of the turbine, it involves changing the swirl speed of the purge air (80) below the platform lip (44) that extends axially from the platform.
Changing the swirling speed of the purge air extends axially from the surface (62) of the shank portion (60) of the turbine bucket (40) and the lower surface (62) of the platform lip (44). A plurality of vacant spaces (1110) arranged along the circumferential length of the angel wing (470) are interrupted by the flow of the purge air (80) , and the plurality of vacant spaces (1110) are included. Each of the plurality of vacant spaces (1110) is defined by a convex surface (1112) and a concave surface (1114), and each of the plurality of vacant spaces (1110) penetrates the angel wing (470) and is described from a radial outward opening (1110A). It extends along the concave surface (1114) and the convex surface (1112) to the radial inward opening (1110B), where the concave surface (1114) is the longitudinal axis (RL) of the turbine bucket (40) and the turbine. The bucket (40) is angled with respect to both directions of rotation (R) so that the radially outward opening (1110A) is radially inward in the direction of rotation (R) of the turbine bucket (40). The method, wherein the concave surface (1114) is behind the convex surface (1112) in the rotational direction (R) of the turbine bucket (40) . The method of claim 1 , wherein at least one of the plurality of voids (1110) comprises a rectangular cross-sectional shape. The method of claim 1 or 2, wherein the plurality of voids (1110) are non-uniformly distributed along the length of the angel wing (470). 13 . The method according to any one . The method according to any one of claims 1 to 4 , further comprising cooling the nozzle surface (30) adjacent to the turbine bucket (40). Changing the swirling speed of the purged air increases the swirling speed of the purged air between the angel wing (470) and the platform lip (44), and the hot gas into the wheel space (26). The method of any one of claims 1 to 5, comprising producing a curtain effect against intrusion.

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