Internal cooling configurations in turbine rotor blades

Abstract

Rotor blade (16) for a turbine (12) of a gas turbine (10), which contains: a blade (25) defined between a concave pressure side (26) and a laterally opposite convex suction side (27), wherein the pressure side (26) and the suction side (27) extend axially between an inflow and an opposite outflow edge (28, 29) and radially between an outer tip (31) and an inner end attached to a foot (21) configured to couple the rotor blade (16) to a rotor disk; a tip cover band (41) which is connected to the outer tip (31) of the blade (25), wherein the tip cover band (41) has a sealing rail (42) projecting from an outer surface (44) and a cutting tooth (43) formed on the sealing rail (42); a cooling configuration (36) comprising a cooling channel for receiving and conveying a coolant through an interior of the rotor blade (16), wherein the cooling channel has fluidically connected segments in which: a feed segment (72) extends radially through the blade (25); a plenum segment (73) is formed within the sealing rail (42); and Branching segments (74) are formed within at least one of the tip cover band (41) and an outer area of ​​the blade (25); wherein each of the branching segments (74) extends between an upstream opening connected to the plenum segment (73) and an outlet opening (75) formed on a target surface, and divides a target interior area in between; where: the plenum segment (73) has an incisor segment formed within the incisor (43) of the sealing rail (42); the tip cover band (41) has a component extending axially and circumferentially, which is held by the outer tip (31) of the blade (25); the top cover strip (41) has an inner surface (45) opposite the outer surface (44) over a radial thickness of the top cover strip (41), and an edge (46) connecting the inner surface (45) with the outer surface (44), which defines an outer profile of the top cover strip (41); the sealing strip (42) projects radially outwards from the outer surface (44) of the tip cover strip (41) and extends circumferentially in a direction of rotation of the running blade (16); and the incisor (43) has a circumferential section of the sealing rail (42) which is axially widened, the axial widening extending radially between the outer surface (44) of the tip cover strip (41) and an outer edge (59) of the sealing rail (42); wherein the guide vane (16) has an inner rounding area (49) which is configured to transition smoothly between a surface of the blade (25) and the inner surface (45) of the tip cover strip (41), and an outer rounding area (48) which is configured to transition smoothly between the outer surface (44) of the tip cover strip (41) and a front (56) of the sealing rail (42) and between the outer surface (44) of the tip cover strip (41) and a rear (57) of the sealing rail (42); wherein the tip cover band (41) comprises: a front part (68) extending forward from the sealing strip (42) to project above the leading edge (28) of the airfoil (25), a rear part (69) extending backward from the sealing strip (42) to project above the trailing edge (29) of the airfoil (25), a pressure part (66) projecting from and projecting above the pressure side (26) of the airfoil (25), a suction part (67) projecting from and projecting above the suction side (27) of the airfoil (25), and an airfoil part (65) defined within a contour of a profile of the airfoil (25) projecting radially through the tip cover band (41); wherein the sealing rail (42) comprises opposite rail sides, where the front (56) of the sealing rail (42) corresponds to the forward direction of the turbine (12) and the rear (57) of the sealing rail (42) corresponds to the reverse direction of the turbine (12); wherein the sealing rail (42) comprises an approximately rectangular profile such that the front (56) and the back (57) of the sealing rail (42) are connected along narrow edges which include: opposite outer and inner edges and rotational front and rotational rear edges (62, 63) wherein the rotational front edge (62) leads the rotational rear edge (63) with respect to the direction of rotation of the impeller blade (16); wherein the target surfaces include at least two of the following: the pressure side (26) of the blade (25); the suction side (27) of the blade (25); the surface corresponding to the inner fillet area (49); the surface corresponding to the outer fillet area (48); the inner surface (45) of the tip cover strip (41); the edge (46) of the tip cover strip (41); the rotation leading edge (62) of the sealing strip (42); the rotation trailing edge (63) of the sealing strip (42); the front (56) of the sealing strip (42); and the rear (57) of the sealing strip (42); wherein the target interior areas comprise at least two of the following: the outer area of ​​the blade (25); the inner rounding area (49); the outer rounding area (48); the leading part (68) of the tip cover (41); the trailing part (69) of the tip cover (41); the pressure part (66) of the tip cover (41); the suction part (67) of the tip cover (41); the blade part (65) of the tip cover (41); and the sealing strip (42); wherein the branching segments (74) contain several branching segments (74) which extend in the circumferential direction such that at least one extends in the direction of rotation and at least one extends away from the direction of rotation; wherein at least one of the several circumferentially extending branching segments (74) contains the outlet opening (75) which is configured to include a near-surface fork (76), wherein the near-surface fork (76) comprises tines (77) which are connected to corresponding individual outlet openings (75) formed on at least two of the target surfaces.

Description

BACKGROUND TO THE INVENTION

[0001] This invention relates to internal cooling channels and blade configurations in gas turbines. In particular, but not limited to, the present application relates to internal cooling channels and structural configurations formed near the radially outer tip of turbine rotor blades.

[0002] It is understood that internal combustion engines or gas turbine drives (“gas turbines”) contain compressor and turbine sections in which rows of blades are stacked axially in stages. Each stage contains a set of circumferentially spaced, fixed stator blades and a set of rotor blades that rotate around a central turbine axis or shaft. In operation, the compressor rotor blades generally rotate around the shaft and, in conjunction with the stator blades, compress a stream of air. The supply of compressed air is then used in a combustion chamber to burn a supply of fuel. The resulting stream of hot, expanding gases from the combustion, i.e., the working fluid, is expanded through the turbine section of the drive. The flow of working fluid through the turbine is redirected from the stator blades to the rotor blades to produce rotation.The turbine blades are connected to a central shaft in such a way that the rotation of the blades drives the shaft in turn. In this way, the energy contained in the fuel is converted into the mechanical energy of the rotating shaft, which can be used, for example, to drive the compressor blades to generate the supply of compressed air required for combustion, or to drive the coils of a generator to produce electricity. During operation, the blades within the turbine are subjected to extreme mechanical and thermal stresses due to the extreme temperatures of the hot gas path, the velocity of the working fluid, and the rotational speed of the drive.

[0003] The development of effective and cost-efficient gas turbines is an ongoing and significant goal. While various strategies for increasing gas turbine efficiency are known, this remains a challenging objective because such alternatives—which include, for example, increasing turbine size, raising temperatures through the hot gas path, and increasing blade rotation speeds—generally impose additional stress on the blades and other components in the hot gas path, which are already under considerable strain. Consequently, improved equipment, processes, or systems that reduce operational stresses on turbine blades, or allow them to better withstand these stresses, thus enabling more effective turbine operation, remain a significant area for technological improvement.

[0004] One strategy for mitigating stresses on the blades is to actively cool them during operation. Such cooling can allow the blades to better withstand higher ignition temperatures and mechanical stresses, which can extend blade life and generally make the turbine more cost-effective and efficient in operation. One approach to cooling blades during operation is through the use of internal cooling channels or circuits. This generally involves passing a relatively cool supply of compressed air, drawn from the compressor, through these internal cooling channels. For a number of reasons, it is understood that great care must be taken in the design and manufacture of these internal cooling channels.

[0005] First, the use of cooling air reduces the efficiency of the turbine. Specifically, air from the compressor that is diverted for cooling is air that could otherwise be used in the combustion process. As a result, using this air necessarily reduces the air available for combustion and thus lowers the overall efficiency. This necessitates highly efficient cooling channels, minimizing the use of air for cooling. Second, current turbine blade designs require sharply shaped, aerodynamic configurations that are thinner and more curved or twisted. These new blade configurations also emphasize compact and efficient channels. These new designs also create spatial constraints that hinder or limit the fabrication of traditional cooling channel configurations using conventional approaches.Third, internal cooling channels must be designed to facilitate lightweight rotor blades while still providing a sufficiently robust structure to withstand extreme loads. That is, while cooling channel design is an effective way to reduce the overall weight of the blade—which improves efficiency and reduces mechanical stress—the blades must still remain highly robust. Cooling channels must therefore be designed to remove both material and weight while still promoting structural robustness. Internal arrangements must also avoid stress concentrations or inadequately cooled areas (or “hot spots”) that can negatively affect part lifespan. Fourth, cooling configurations must also be designed so that the delivered coolant promotes surface cooling and efficient aerodynamic operation.Since cooling channels typically release coolant into the working fluid flow path after circulating through the internal cooling channels, another design consideration concerns the use of released coolant for surface cooling and the associated minimization of aerodynamic losses. Expelled coolant is often relied upon to provide cooling to outer surfaces or areas of the blade after its release, and this must be integrated with both internal cooling strategies and aerodynamic performance.

[0006] It is understood that, according to these and other criteria, the design of internal cooling configurations within turbine blades involves many complex and often conflicting considerations. New designs that balance these in a way that optimizes or improves one or more desired performance criteria—while still appropriately favoring structural strength, part longevity, cost-effective turbine operation, and efficient coolant use—represent significant technological advances.

[0007] DE 199 04 229 A1 discloses a cooled turbine blade with a blade, a tip cover band comprising a sealing strip and a cutting tooth formed on the sealing strip, and a cooling configuration including a cooling channel for receiving and guiding a coolant through the interior of the turbine blade. The cooling channel comprises fluidically connected segments with a feed segment extending radially through the blade, a plenum segment within the sealing strip, and branching segments formed within the sealing strip that fluidly connect the plenum segment to outlet openings formed on an outer edge and on side edges of the sealing strip.

[0008] JP 2011-1919A discloses a turbine rotor blade with a tip trim strip having an outer profile with a notched section for the engagement of a tip trim strip of an adjacent turbine rotor blade when installed in a series of identically configured blades. The tip trim strip has a sealing rib on its surface and a cooling structure, which includes cooling openings at several locations on the tip trim strip, arranged parallel to the sealing rib. At least one cooling opening extends through the tip trim strip and is inclined to the surface of the tip trim strip to facilitate the flow of cooling air or combustion gas from the rotating tip trim strip. The cooling opening comprises an inlet opening to the upstream side of the combustion gas on the surface of the tip trim strip and an outlet opening to the inside of the tip trim strip.

[0009] Based on this, one object of the invention is to create an improved internal cooling configuration for a turbine blade of a gas turbine, which increases performance and cooling efficiency and enables efficient use of coolant for surface cooling.

[0010] To solve this problem, a turbine blade for a gas turbine with the features of independent claim 1 and a gas turbine with a series of such turbine blades according to claim 7 have been provided. Particularly preferred embodiments of the invention are specified in the dependent claims. BRIEF DESCRIPTION OF THE INVENTION

[0011] In one aspect of the invention, a turbine blade is provided, comprising: a blade defined between a concave pressure side and a laterally opposite convex suction side, wherein the pressure side and the suction side extend axially between opposing inlet and outlet edges and radially between an outer tip and an inner end attached to a foot configured to couple the blade to a rotor disk; a tip cover band connected to the outer tip of the blade, the tip cover band comprising a sealing rail projecting from an outer surface and a cutting tooth formed on the sealing rail; and a cooling configuration comprising a cooling channel for receiving and guiding a coolant through an interior of the blade.The cooling channel comprises flow-connected segments in which: an inlet segment extends radially through the blade; a plenum segment is formed within the sealing strip; and branching segments are formed within at least one of the tip shroud and an outer region of the blade. Each of the branching segments extends between an upstream opening connected to the cutting tooth segment and an outlet opening formed on a target surface, and bisects a target interior region between them.

[0012] In the rotor blade according to the invention, the plenum segment comprises a cutting tooth segment formed within the cutting tooth of the sealing strip. The tip trim has a component extending axially and circumferentially, held by the outer tip of the blade. The tip trim has an inner surface opposite the outer surface, extending over a radial thickness of the tip trim, and an edge that defines an outer profile of the tip trim and connects the inner surface to the outer surface. The sealing strip projects radially outward from the outer surface of the tip trim and extends circumferentially in a direction of rotation of the rotor blade. The cutting tooth comprises a circumferential section of the sealing strip that is axially widened, the axial widening extending radially between the outer surface of the tip trim and the outer edge of the sealing strip.

[0013] Furthermore, the impeller blade according to the invention comprises an inner rounding or transition area which is designed to provide a smooth transition between a surface of the impeller blade and the inner surface of the tip cover strip, and an outer rounding or transition area which is designed to provide a smooth transition between the outer surface of the tip cover strip and a front side of the sealing strip and between the outer surface of the tip cover strip and a rear side of the sealing strip.The tip trim band comprises: a front part extending forward from the sealing strip to project beyond the leading edge of the airfoil; a rear part extending backward from the sealing strip to project beyond the trailing edge of the airfoil; a pressure part projecting from and projecting above the pressure side of the airfoil; a suction part projecting from and projecting above the suction side of the airfoil; and an airfoil portion defined within a contour of an airfoil profile projecting radially through the tip trim band.

[0014] Furthermore, the sealing rail of the turbine blade according to the invention comprises opposing rail sides, in which a front side of the sealing rail corresponds to the forward direction of the turbine and a rear side of the sealing rail corresponds to the reverse direction of the turbine. The front and rear sides of the sealing rail can each be arranged at a steep angle relative to the outer surface of the tip cover strip.

[0015] In each blade according to the invention, the sealing strip comprises an approximately right-angled profile such that the front and back of the sealing strip are connected along narrow edges, which include: opposite outer and inner edges, in which the inner edge is defined at the connection that the sealing strip makes with the outer surface of the tip cover strip, and the outer edge is offset from the outer surface of the tip cover strip by a radial height of the sealing strip; and rotational front and rotational rear edges, in which the rotational front edge leads the rotational rear edge relative to the direction of rotation of the blade.

[0016] In each rotor blade according to the invention, the target surfaces comprise at least two of the following: the pressure side of the blade; the suction side of the blade; the surface corresponding to the inner rounding area; the surface corresponding to the outer rounding area; the inner surface of the tip trim band; the edge of the tip trim band; the rotational leading edge of the sealing strip; the rotational trailing edge of the sealing strip; the front of the sealing strip; and the rear of the sealing strip.

[0017] In each rotor blade according to the invention, the target inner regions comprise at least two of the following: the outer region of the blade; the inner rounding region; the outer rounding region; the front part of the tip cover band; the rear part of the tip cover band; the pressure part of the tip cover band; the suction part of the tip cover band; the blade part of the tip cover band; and the sealing strip.

[0018] In each rotor blade according to the invention, the branching segments comprise several branching segments extending circumferentially such that at least one extends in the direction of rotation and at least one extends away from the direction of rotation. At least one of the several circumferentially extending branching segments contains the outlet opening, which is configured to include a near-surface fork, wherein the near-surface fork comprises prongs connected to corresponding individual outlet openings formed on at least two of the target surfaces.

[0019] In one embodiment, the cutting tooth segment may comprise: a plenum completely contained within the cutting tooth; a position in a central circumferential region of the sealing rail; a flow cross-section larger than the flow cross-section of each of the branching segments branching from it; and a flow cross-section larger than the flow cross-section of the associated feed segment. Furthermore, the feed segment may comprise: an upstream end formed by the root of the rotor blade, at which the feed segment is fluidically connected to an air source, and a downstream end fluidically connected to the cutting tooth segment; and a radially oriented linear channel through the blade. The branching segments may further comprise outlet openings that fluidically communicate with the working fluid flow path.

[0020] Additionally or alternatively, the flow cross-sections of the branching segments can be dimensioned according to a desired coolant flow dimension through the target internal areas. Furthermore, an inner pressure fillet area can comprise the inner fillet area between the pressure side of the airfoil and the inner surface of the tip trim; an inner suction fillet area can comprise the inner fillet area between the suction side of the airfoil and the inner surface of the tip trim; a leading outer fillet area can comprise the outer fillet area between the leading edge of the sealing strip and the outer surface of the tip trim; and a trailing outer fillet area can comprise the outer fillet area between the trailing edge of the sealing strip and the outer surface of the tip trim.

[0021] Furthermore, or as a further alternative, the outer profile of the tip cover strip may include a notched section for engagement of a tip cover strip of an adjacent running blade when installed in a series of identically configured running blades, and the sealing rail may extend over substantially the entire circumferential length of the outer surface of the tip cover strip, the circumferential length of the tip cover strip being able to include a length of the tip cover strip in the direction of rotation.

[0022] In addition, or as a further alternative, the cutting tooth can be arranged within the blade portion of the outer surface of the tip cover band, wherein the cutting tooth can have a rectangular profile, and wherein the cutting tooth can comprise an enlarged volume corresponding to a flow cross-section of the cutting tooth segment of the cooling channel.

[0023] In the previously mentioned preferred embodiments, the multiple circumferentially extending branching segments can each include an inner slope, and the target surfaces of the multiple circumferentially extending branching segments can include the inner surface of the platform.

[0024] In each of the latter preferred embodiments, the target surfaces of the multiple circumferentially extending branching segments can comprise surfaces relating to the inner rounding area.

[0025] Additionally or alternatively, the target surfaces of the multiple circumferentially extending branching segments can include surfaces related to both the inner pressure rounding area and the inner suction rounding area.

[0026] In each of the latter preferred embodiments, the target inner regions of the multiple circumferentially extending branching segments can include both the inner pressure rounding region and the inner suction rounding region.

[0027] In each of the latter preferred embodiments, the target surfaces of the multiple circumferentially extending branching segments can include both the rotational front edge and the rotational rear edge of the sealing rail.

[0028] In each of the latter preferred embodiments, at least one of the several circumferentially extending branching segments can contain the outlet opening which is configured to include a near-surface fork, wherein the near-surface fork can include prongs which are connected to corresponding individual outlet openings formed by the rotational front edge of the sealing rail and the rotational rear edge of the sealing rail.

[0029] Additionally, a first tine of the near-surface fork can be connected to one of the outlets formed on the edge of the tip cover band, and a second tine of the near-surface fork can be connected to one of the outlets formed on the inner surface of the tip cover band.

[0030] In each of the latter preferred embodiments, a first prong of the near-surface fork can be connected to one of the outlets formed at a point of rotation from the front edge and the rear edge of rotation of the sealing rail, and a second prong of the near-surface fork can be connected to one of the outlets formed at a point of rotation from the front and the rear of the sealing rail.

[0031] In another aspect of the invention, a gas turbine is created which has a series of rotor blades in a turbine, wherein the series of rotor blades comprises several rotor blades as described above.

[0032] These and other features of the present application will become apparent upon reading the following detailed description of the preferred embodiments in conjunction with the drawings and the attached claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] These and other features of this invention will become more fully understandable and apparent through a careful study of the following more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, in which: Fig. 1 a schematic representation of an exemplary gas turbine which may contain turbine blades according to aspects and embodiments of the present application; Fig. 2 a sectional view of the compressor section of the gas turbine of Fig. 1 is; Fig. 3 a sectional view of the turbine section of the gas turbine of Fig. 1 is; Fig. 4 is a side view of an exemplary turbine rotor blade which may include an internal cooling configuration and a structural arrangement according to aspects and embodiments of the present application; Fig. 5 a sectional view along the line of sight 5 - 5 of the Fig. 4 is; Fig. 6 a sectional view along the line of sight 6 - 6 of the Fig. 4 is; Fig. 7 a sectional view along the line of sight 7 - 7 of the Fig. 4 is; Fig. 8 is a perspective view of an exemplary turbine rotor blade which may include a tip cover band and a configuration according to aspects and embodiments of the present application; Fig. 9 an enlarged perspective view of the lace cover band of Fig. 8 is; Fig. 10 an external perspective of an installed arrangement of turbine rotor blades, which may include tip deck bands and configurations according to aspects and embodiments of the present application; Fig. 11 an external perspective of a lace cover band which may contain a configuration according to aspects and embodiments of the present application; Fig. 12 is a perspective view of a top cover band incorporating an internal cooling configuration according to aspects and embodiments of the present application; Fig. 13 an interior view of the lace trim of Fig. 12 is; Fig. 14 is a perspective view of a top cover band incorporating an alternative internal cooling configuration according to aspects and embodiments of the present application; Fig. 15 an exterior view of the lace trim of Fig. 14 is; Fig. 16 a perspective view of a top cover band incorporating an alternative internal cooling configuration according to aspects and embodiments of the present application; and Fig. 17 another view of the lace trim of Fig. 16, which contains an enlarged component detail. DETAILED DESCRIPTION OF THE INVENTION

[0034] Aspects and advantages of the present application are set forth below in the following description, or may be apparent from the description, or may be discovered through the exercise of the invention. Detailed reference is now made to present embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical designations to refer to features in the drawings. Identical or similar designations in the drawings and the description may be used to refer to identical or similar parts of embodiments of the invention. It is understood that each example is provided by means of the explanation of the invention and not the limitation of the invention.Indeed, it will be apparent to those skilled in the art that modifications and variations of the present invention can be made without altering its scope or spirit. For example, features presented or described as part of one embodiment can be used in another embodiment to give yet another embodiment. It is intended that such modifications and variations falling within the scope of the present invention are contained within the appended claims and their equivalents. It is understood that the scopes and limits mentioned herein include all sub-scopes within the prescribed limits, including the limits themselves, unless otherwise specified. In addition, certain terms have been chosen to describe the present invention and its component subsystems and parts.Wherever possible, these terms were chosen based on the terminology customary in the technological field. However, it is understood that these terms are often subject to different configurations. For example, what is referred to here as a single component may elsewhere refer to consisting of several components, or what is referred to here as containing several components may elsewhere be referred to as a single component. In understanding the scope of the present invention, attention should be paid not only to the specific terminology used, but also to the accompanying description and context, as well as the structure, configuration, function, and / or use of the component referred to and described therein, including how the term relates to the various figures, and, of course, the precise use of the terminology in the accompanying claims.Furthermore, while the following examples are presented with regard to certain types of gas turbines or turbine drives, the technology of the present application may also be applicable without limitation to other categories of turbine drives, as would be understood by a person skilled in the art in the relevant technological fields. Accordingly, it is understood that, unless otherwise stated, the use of the term "gas turbine" herein is intended to be broad and limited with respect to the applicability of the present invention to the various types of turbines.

[0035] Given how gas turbines operate, several terms prove particularly useful for describing certain aspects of their function. These terms and their definitions, unless specifically stated otherwise, are as follows. As is understood, such terms can be used both when describing or claiming the gas turbine or one of its major subsystems—that is, the compressor, combustion chamber, or turbine—and when describing or claiming components or subsystems for use therein. In the latter case, the terminology should be understood as describing the components as they would be present within the gas turbine or major subsystems if properly installed and / or functioning.

[0036] Accordingly, the terms "front" and "back" refer to directions relative to the orientation of the gas turbine and, in particular, the relative position of the compressor and turbine sections of the drive. Thus, the term "front," as used here, refers to the compressor end, whereas "back" refers to the turbine end. It is understood that either of these terms can be used to indicate the direction of motion or the relative position along the turbine's central axis. As stated above, these terms can be used to describe attributes of the gas turbine or one of its major subsystems, as well as components or subcomponents positioned therein.Thus, if, for example, a component such as a turbine blade is described or claimed to have a "front side," it can be understood as referring to a side that is oriented in the forward direction as defined by the orientation of the gas turbine (i.e., the positioning of the combustion chamber and turbine subsystems). Unless otherwise stated, this assumption also applies to the following descriptive terms.

[0037] The terms "downstream" and "upstream" are used here to indicate a position within a specified channel or flow path relative to the direction of flow passing through it (hereinafter "flow direction"). Thus, "downstream" refers to the direction in which a fluid flows through the specified channel, while "upstream" refers to the opposite direction. These terms can be defined as referring to what a person skilled in the art would understand as the flow direction through the channel during normal or expected operation. It is understood that the working fluid within the compressor and turbine sections of the gas turbine is directed downstream and through an annular working fluid flow path, typically defined around the central and common axis of the gas turbine.As such, the term "flow direction" within the compressor and turbine sections of the drive, as used here, refers to a reference direction that represents an idealized or generalized direction of flow of working fluid through the working fluid flow path of the drive under an expected or normal operating condition. Thus, the "flow direction" terminology within the compressor and turbine sections refers to a flow that runs parallel to the central axis of the gas turbine and is oriented in the downstream or rearward direction.

[0038] Accordingly, the flow of working fluid through the working fluid flow path of the gas turbine can be described, for example, as beginning as compressed air in the compressor, becoming combustion gases in the combustion chamber when burned with a fuel, and ultimately expanding in the direction of flow after passing through the turbine. Similarly, the flow of working fluid can be described as beginning at a front or upstream point, moving to a front or upstream end of the gas turbine, generally moving in a downstream or backstream direction, and ultimately terminating at a back or downstream point at a back or downstream end of the gas turbine.

[0039] Since many components of gas turbines, such as compressor and turbine blades, rotate during operation, the terms "rotationally forward" and "rotationally aft" can be used to distinguish the relative positioning of subcomponents or subsections per expected rotation within the drive. Thus, it is understood that these terms can differentiate the position within the compressor or turbine per direction of rotation (hereinafter "direction of rotation"). As used here, such a direction of rotation can be understood as the expected direction of rotation for a component during normal or expected operation of the gas turbine.

[0040] Additionally, given the configuration of gas turbines, particularly the arrangement of the compressor and turbine sections around a common shaft or rotor, and the common cylindrical configuration of many combustion chamber types, terms describing a position relative to an axis can be regularly used here. In this context, it is understood that the term "radial" refers to a movement or position perpendicular to an axis. In connection with this, it may be necessary to describe a relative distance from the central axis. In such cases, for example, if a first component is closer to the central axis than a second component, the first component is described as either "radially inward" or "inward" from the second component.Conversely, if the first component is located further from the central axis, the first component is described as either "radially outward" or "outside" the second component. As used here, the term "axial" refers to a movement or position parallel to an axis, while the term "circumferential" refers to a movement or position around an axis. Unless otherwise specified or immediately apparent from the context, these terms should be established as referring to the central axis of the compressor and / or turbine sections of the gas turbine as defined by the rotor extending through each of them, even though the terms describe or claim attributes of non-integral components—such as rotor and stator blades—operating therein.Unless otherwise specified, the terms may be used relative to the longitudinal axis of certain components or subsystems within the gas turbine, such as the longitudinal axis around which conventional cylindrical or “tube” combustion chambers are usually arranged.

[0041] Ultimately, the term "rotating blade" refers, without further specificity, to the rotating blades of either the compressor or the turbine and can therefore include both compressor rotor blades and turbine rotor blades. The term "stator blade," without further specificity, refers to the stationary blades of either the compressor or the turbine and can therefore include both compressor stator blades and turbine stator blades. The term "blades" can be used to refer generally to any type of blade. Thus, the term "blades," without further specificity, includes all types of gas turbine blades, including compressor rotor blades, compressor stator blades, turbine rotor blades, turbine stator blades, and the like.

[0042] As background, and now specifically referring to the characters, they present Fig. 1, Fig. 2 to Fig. 3. An exemplary gas turbine according to the present invention, or within which the present invention can be used. It is understood by those skilled in the art that the present invention cannot be limited to this type of use. As indicated, the present invention can be used in gas turbines such as those used in power generation and in aircraft, steam turbines, and other types of rotary machines, as would be understood by a person skilled in the art. Therefore, the examples provided are not intended to be limiting, unless otherwise stated. Fig. Figure 1 is a schematic representation of a gas turbine. In general, gas turbines operate by extracting energy from a pressurized stream of hot gas produced by burning a fuel in a stream of compressed air. As shown in Fig. As shown in Figure 1, the gas turbine 10 can be equipped with an axial compressor 11, which is mechanically coupled to a downstream turbine section or turbine 12 by a common shaft or rotor, and a combustion chamber 13, which is arranged between the compressor 11 and the turbine 12. As shown in Fig. As shown in Figure 1, the gas turbine can be designed around a common central axis 19.

[0043] Fig. Figure 2 shows a view of an exemplary multi-stage axial compressor 11, which is used in the gas turbine of Fig. 1 can be used. As shown, the compressor 11 can have several stages, each containing a series of compressor impeller blades 14 and a series of compressor stator blades 15. Thus, a first stage can contain a series of compressor impeller blades 14 rotating around a central shaft, followed by a series of compressor stator blades 15 that remain stationary during operation. Fig. Figure 3 shows a partial view of an exemplary turbine section or turbine 12, which is / are located in the gas turbine of Fig. 1 can be used. The turbine 12 can also contain multiple stages. Three exemplary stages are shown, but there may be more or fewer. Each stage can contain several turbine guide vanes or stator blades 17, which remain stationary during operation, followed by several turbine blades or rotor blades 16, which rotate around the shaft during operation. The turbine stator blades 17 are generally spaced circumferentially apart and attached to an outer casing around the axis of rotation. The turbine rotor blades 16 can be mounted on a turbine impeller or rotor disk (not shown) for rotation about a central axis. It is understood that the turbine stator blades 17 and the turbine rotor blades 16 lie in the hot gas path or the working fluid flow path through the turbine 12.The direction of the flow of combustion gases or working fluid within the working fluid flow path is indicated by the arrow.

[0044] In an operational example for the gas turbine 10, the rotation of the compressor blades 14 within the axial compressor 11 can compress an airflow. Energy can be released in the combustion chamber 13 when the compressed air is mixed with a fuel and ignited. The resulting flow of hot gases or working fluid from the combustion chamber 13 is then directed over the turbine blades 16, causing them to rotate around the shaft. In this way, the energy of the working fluid flow is converted into the mechanical energy of the rotating blades and, given the connection between the blades and the shaft, into the mechanical energy of the rotating shaft. The shaft's mechanical energy can then be used to drive the rotation of the compressor blades 14, thus generating the necessary supply of compressed air, and, for example, to drive a generator to produce electricity.

[0045] The background is provided by Fig. 4, Fig. 5, Fig. 6 to Fig. Seven views of a turbine rotor blade 16 are provided, according to which or within which aspects of the present invention can be exercised. As is understood, these figures are provided to illustrate general configurations of rotor blades and to delineate spatial relationships between components and areas within such blades for later reference, while also describing geometric constraints and other criteria relating to their internal and external construction. While the blade in this example is a rotor blade, it is understood that, unless otherwise stated, the present invention can also be applied to other types of blades within the gas turbine.As stated above, the description of such components may contain terminology that derives its meaning from the orientation and function of the gas turbine and, in particular, the working fluid flow path, and should therefore be understood in this context, i.e., that such a description assumes that the rotor blade is properly installed and operating within the drive under expected or normal conditions.

[0046] The rotor blade 16, as shown, can include a base 21 configured for attachment to a rotor disk. The base 21 can, for example, include a dovetail 22 configured for mounting in a corresponding dovetail groove on the circumference of a rotor disk. The base 21 can further include a shaft 23 extending between the dovetail 22 and a platform 24. The platform 24, as shown, generally forms the connection point between the base 21 and a blade 25, which is the active component of the rotor blade 16 that interrupts the flow of working fluid through the turbine 12 and produces the desired rotation. The platform 24 can define the inner end of the blade 25. The platform can also define a section of the inner boundary of the working fluid flow path through the turbine 12.

[0047] The blade 25 of the rotor blade can typically include a concave pressure side 26 and a circumferentially or laterally opposing convex suction side 27. The pressure side 26 and the suction side 27 can each extend axially between opposing leading and trailing edges 28, 29, and radially between an inner end, which can be defined at the connection with the platform 24, and an outer tip 31. The blade 25 can have a curved or contoured shape designed to promote a desired aerodynamic performance. As shown in the Fig. 4 and Fig. As shown in Figure 5, the shape of the airfoil 25 can gradually taper along its length between the platform 24 and the outer tip 31. This taper can include axial tapering, which narrows the distance between the leading edge 28 and the trailing edge 29 of the airfoil 25, as shown in Figure 5. Fig. 4 shown, as well as a tapering in the circumferential direction that reduces the thickness of the impeller blade 25, as defined between the suction side 27 and the pressure side 26, as shown in Fig. 5 shown. As in the Fig. 6 and Fig. As shown in Figure 7, the contoured shape of the blade 25 can further include a coil around the longitudinal axis of the blade 25 as it extends from the platform 24. It is understood that the coil can be included to gradually vary the staggered angle of the blade 25 between the inner end and the outer tip 31.

[0048] For descriptive purposes, the blade 25 of the running blade 16 can be shown as in Fig. Figure 4 shows, and further describes as comprising one or one and a half leading edge section and one or one and a half trailing edge section, defined on each side of an axial centerline 32. The axial centerline 32, as used here, can be formed by connecting the midpoints 34 of the skeleton lines 35 of the airfoil 25 between the platform 24 and the outer tip 31. Additionally, the airfoil 25 can be described as comprising two radially stacked sections defined inside and outside by a radial centerline 33 of the airfoil 25. Thus, as used here, one or one and a half inner section of the airfoil 25 extends between the platform 24 and the radial centerline 33, while one or one and a half outer section extends between the radial centerline 33 and the outer tip 31.Ultimately, the airfoil 25 can be described as containing one or one and a half pressure side section and one or one and a half suction side section, which, as is understood, are defined on each side of the skeleton line 35 of the airfoil 25 and the corresponding side 26, 27 of the airfoil 25.

[0049] The rotor blade 16 can further include an internal cooling configuration 36 comprising one or more cooling channels 37 through which a coolant is circulated during operation. Such cooling channels 37 can extend radially outward from a connection to a supply source formed by the base 21 of the rotor blade 16. The cooling channels 37 can be linear, curved, or a combination thereof, and can include one or more outlet or surface openings through which coolant is discharged from the rotor blade 16 and into the working fluid flow path.

[0050] The Fig. 8, Fig. 9, Fig. 10 to Fig. Figure 11 represents a turbine rotor blade 16 which has a tip cover strip 41 according to the present invention or within which the present invention can be used. As is understood, Fig. 8 a perspective view of an exemplary turbine rotor blade 16 which includes a tip cover strip 41, while Fig. 9 is an enlarged view of section 41 of the lace cover band. Fig. Figure 10 shows a profile from an external perspective of an exemplary installed arrangement of running blades 16 with a tip cover strip. Finally, it shows Fig. 11 an enlarged external profile view of a lace cover band 41 is provided, which can be used to delineate the different areas within lace cover bands in the following discussion.

[0051] As shown, the tip trim 41 can be located near or at the outer end of the blade 25. The tip trim 41 can include a flat plate or planar component extending axially and circumferentially, which is held at its center by the blade 25. For descriptive purposes, the tip trim 41 can include an inner surface 45, an outer surface 44, and an edge 46. As shown, the inner surface 45 faces the outer surface 44 across the narrow radial thickness of the tip trim 41, while the edge 46 connects the inner surface 45 to the outer surface 44 and, as used here, defines a peripheral or outer profile of the tip trim 41.

[0052] A sealing strip 42 can be arranged along the outer surface 44 of the tip cover 41. Generally, the sealing strip 42, as shown, is a fin-like projection extending radially outward from the outer surface 44 of the tip cover 41. The sealing strip 42 can extend circumferentially between opposite ends of the tip cover 41 in the direction of rotation, or "rotational direction," of the rotor blade 16. As understood, the sealing strip 42 can be used to prevent leakage of working fluid through the radial gap that typically exists between the tip cover 41 and the surrounding stationary components that define the outer boundary of the working fluid flow path through the turbine. According to conventional designs, the sealing strip 42 can extend radially in an abrasion-resistant, stationary honeycomb-shaped seal opposite it across this gap.The sealing rail 42 can extend substantially over the entire circumferential length of the outer surface 44 of the end cap 41. As used here, the length of the end cap 41 is the length of the end cap 41 in the direction of rotation 50. For descriptive purposes, the sealing rail 42 can have opposing rail faces, with a front face 56 corresponding to the forward direction of the gas turbine and a back face 57 corresponding to the reverse direction. It is understood that the front face 56 thus points toward or into the flow direction of the working fluid, while the back face 57 points away from it. The front face 56 and back face 57 of the sealing rail 42 can each be arranged to form a steep angle relative to the outer surface 44 of the end cap 41.

[0053] Although other configurations are possible, the sealing strip 42 can have a nearly rectangular profile. The front 56 and the rear 57 of the sealing strip 42 can connect along circumferentially narrow edges, which, as used here, include: opposing and nearly parallel outer and inner edges, and opposing and nearly parallel rotational front and rear edges. In particular, the inner edge of the sealing strip 42 can be defined at the junction between the sealing strip 42 and the outer surface 44 of the top cover strip 41. As is understood, the inner edge is somewhat obscured due to the rounded areas formed for structural purposes between the sealing strip 42 and the top cover strip 41, and is therefore not specifically designated by a numerical identifier. The outer edge 59 of the sealing strip 42 is radially offset from the outer surface 44 of the top cover strip 41.As can be understood, this radial offset generally represents the radial height of the sealing strip 42. As shown, a rotating leading edge 62 of the sealing strip 42 projects radially from the edge 46 of the tip cover 41, which extends beyond the suction side 27 of the blade 25. For this reason, the rotating leading edge 62 is the component that "leads" the sealing strip 42 when the rotor blade 16 rotates during operation. At the opposite end of the sealing strip 42, a rotating trailing edge 63 projects radially from the edge 46 of the tip cover 41, which extends beyond the pressure side 26 of the blade 25. Given this arrangement, the rotating trailing edge 63 is the component that "trails" the sealing strip 42 when the rotor blade 16 rotates during operation.

[0054] A cutting tooth 43 can be arranged on the sealing strip 42. The cutting tooth 43 can be provided for cutting a groove in the abrasive coating or the honeycomb structure of the stationary cover strip, which is slightly wider than the width of the sealing strip 42. The honeycomb structure can be provided to improve sealing stability, and the use of the cutting tooth 43 can reduce spillage and rubbing between stationary and rotating parts by clearing this wider path. The cutting tooth 43 is generally located in an area of ​​increased width along the circumferential length of the sealing strip 42. In particular, the cutting tooth 43 can include a circumferential section of the sealing strip 42 that is axially widened. This axially widened area can extend radially between the outer surface 44 of the top cover strip 41 and the outer edge of the sealing strip 42.The cutting tooth 43 can be located near the center or middle area of ​​the sealing strip 42. As shown below, the cutting tooth 43 can be located within the blade portion of the outer surface 44 of the tip cover strip 41. The cutting tooth 43 can have a nearly rectangular profile, although other profiles are also possible.

[0055] The tip trim 41 can include rounded areas 48, 49 designed to provide smooth surface transitions between the diverging surfaces of the tip trim 41 and the blade 25, as well as between the tip trim 41 and the sealing strip 42. Configurations of the tip trim 41 can include an outer rounded area 48 formed between the outer surface 44 of the tip trim 41 and the front 56 and rear 57 of the sealing strip 42. The tip trim 41 can further include an inner rounded area 49 formed between the inner surface 45 of the tip trim 41 and the pressure and suction sides 26, 27 of the blade 25.As can be understood, the inner rounding region 49 can be described in particular as comprising: an inner pressure rounding region, which is the section formed between the pressure side 26 of the blade 25 and the inner surface 45 of the tip cover 41; and an inner suction rounding region, which is the section formed between the suction side 26 of the blade 25 and the inner surface 45 of the tip cover 41. The outer rounding region 48 can be described in particular as comprising: a front outer rounding region, which is the section formed between the front face 56 of the sealing strip 42 and the outer surface 44 of the tip cover 41; and a rear outer rounding region, which is the section formed between the rear face 57 of the sealing strip 42 and the outer surface 44 of the tip cover 41.As shown, each of these rounded areas 49, 48 can be configured to provide smoothly curving transitions between the various planar surfaces that form abrupt or steep angular transitions. It is understood that such rounded areas can increase aerodynamic performance and distribute stress concentrations that would otherwise occur in these surfaces. Even so, these surfaces remain highly stressed due to the projecting or cantilevered load of the tip cover 41 and the rotational speed of the turbine. It is understood that, without adequate cooling, these stresses in these surfaces represent a significant limitation on the service life of the component.

[0056] By now focusing in particular on Fig. As referenced in section 10, tip cover bands 41 can be configured to include a contact connection point where contact surfaces or edges engage with corresponding surfaces or edges formed on the tip cover bands 41 of adjacent rotor blades during operation. As is recognized, this can be done, for example, to reduce leakage or harmful vibrations. Fig. Figure 10 provides an external view of the tip trim bands 41 on turbine rotor blades as they might appear in an assembled state. As shown, for descriptive purposes, the edge 46 of the tip trim band 41 can include a rotationally forward contact edge 52 and a rotationally aft contact edge 53 relative to the direction of rotation 50. Thus, as shown, the tip trim band 41 can be configured in a rotationally guided position with a rotationally aft contact edge 53 that comes into contact with, or is in close proximity to, the rotationally forward contact edge 52 of the tip trim band 41 in a rotationally aft position relative to it. While this contact area between the adjacent tip trim bands 41 can generally be referred to as a contact joint, it can also be described as a "Z-notch" joint, given the profile of the exemplary configuration.Other configurations are also possible. When forming the contact point, the edge 46 of the tip cover strip 41 can be provided with a notched section which is intended to contact or engage with an adjacent and similarly configured tip cover strip 41 in a predetermined manner.

[0057] By now focusing in particular on Fig. As referenced in Figure 11, the outer profile of the tip trim 41 can have an arc shape. Although other configurations are possible, the exemplary arc shape is the one that performs well in terms of reducing leakage while also minimizing weight. Whatever the profile, it is understood that the areas or parts that constitute the tip trim 41 are described in terms of their arrangement relative to the sealing strip 42 and / or the profile of the underlying blade 25. Thus, as used here, a blade part 65 of the tip trim 41 is the part defined within a profile of the blade 25 that projects radially through the tip trim 41.A pressure portion 66 of the tip deck 41 is the part that projects from and over the pressure side 26 of the blade 25, while a suction portion 67 of the tip deck 41 is the part that projects from and over the suction side 27 of the blade 25. Finally, a leading portion 68 of the tip deck 41 is the part that extends forward from the sealing strip 42 to project over the leading edge 28 of the blade 25, while a trailing portion 69 of the tip deck 41 is the part that extends backward from the sealing strip 42 to project over the trailing edge 29 of the blade 25.

[0058] By now focusing in particular on the Fig. 12, Fig. 13, Fig. 14, Fig. 15, Fig. 16 to Fig. With reference to Figure 17, some internal cooling configurations are presented which are consistent with aspects and exemplary embodiments of the present invention. As is understood, these examples are described with reference to and in light of the systems and related concepts already provided herein, in particular those discussed with respect to the preceding figures.

[0059] The present invention may include an internal cooling configuration within the blades and tip trim bands of gas turbine rotor blades. Such cooling configurations may include internal cooling channels for receiving and conveying a coolant through the interior of the rotor blade. According to such cooling configurations, the cooling channels of the present invention may include fluidically connected sections or segments, which may include: a feed segment 72 extending radially through the blade 25; a plenum segment or cutting tooth segment 73 formed within the sealing rail 42, or more specifically within the cutting tooth 43 of the sealing rail 42; and branching segments 74 extending from the cutting tooth segment 73. As discussed, the branching segments 74 may be formed within the tip trim band 41, the sealing rail 42, and more generally on an outer region of the blade 25 (i.e.,, the section of the blade 25 near or adjacent to the tip cover 41). As shown, the branching segments 74 can extend between an upstream opening connected to the cutting tooth segment 73 and a downstream opening which, because it is formed on a target surface on an outer surface of the rotor blade 16, is here referred to as an outlet opening 75. Furthermore, as will be discussed later, the branching segments 74 can be configured to extend through or divide an inner region of the rotor blade 16.

[0060] According to the present configurations, the feed segment 72 can, as shown, include an upstream end formed by the root 21 of the rotor blade 16, which can connect the feed segment 72 to a coolant source. At a downstream end, the feed segment 72 can be fluidically connected to the cutting tooth segment 73. According to exemplary embodiments, the feed segment 72 can be configured as a radially oriented linear channel through the blade 25.

[0061] The plenum segment or cutter segment 73 can be configured as a distributor or plenum through which the supply of air directed thereto is distributed to the various branch segments 74. Accordingly, the flow cross-section of the cutter segment 73 can be larger than the flow cross-section of each of the branch segments 74 branching off from it. According to exemplary arrangements, the flow cross-section of the cutter segment 73 can also be larger than the flow cross-section of the associated supply segment 72. The cutter segment 73 can be completely contained within the cutter 43. Alternatively, the cutter segment 73 can substantially overlap with an inner region defined within the cutter 43. In further embodiments, the cutter segment 73 is formed within the sealing strip 42 and / or the tip cover strip 41.

[0062] The branching segments 74 can extend from the cutting tooth segment 73 along various paths to cut the target surfaces and internal regions according to a desired cooling strategy for the blade 25 and / or the tip cover 41. The flow cross-sections of the branching segments 74 can be dimensioned according to the desired coolant flow to the target surfaces and through the target internal regions. The branching segments 74 can be connected to the outlet openings 75, which, because the outlet openings 75 are formed on an outer surface of the rotor blade 16, results in the cooling configuration 36 of the present invention communicating fluid-wise with the working fluid flow path through the turbine 12.

[0063] The outlet openings 75 of the branching segments 74 can be formed on predetermined target surfaces. These target surfaces can generally include some of the surfaces of the blade 25 and / or the tip cover 41 already discussed herein. According to exemplary embodiments, the target surfaces for the cooling configuration 36 can include one or more of the following: the pressure side 26 of the blade 25; the suction side 27 of the blade 25; the surface corresponding to the inner fillet 49; the surface corresponding to the outer fillet 48; the inner surface 45 of the tip cover 41; the edge 46 of the tip cover 41; the rotational leading edge 62 of the sealing strip 42; the rotational trailing edge 63 of the sealing strip 42; the front 56 of the sealing strip 42; and the rear 57 of the sealing strip 42.According to the present invention, the target internal areas for the present cooling configurations 36 can include one or more of the following: the outer area of ​​the blade 25 close to or adjacent to the tip cover 41; the inner rounding area 49; the outer rounding area 48; the front part 68 of the tip cover 41; the rear part 69 of the tip cover 41; the pressure part 66 of the tip cover 41; the suction part 67 of the tip cover 41; the blade part 65 of the tip cover 41; and the sealing strip 42.

[0064] According to certain preferred embodiments, the cooling configurations 36 of the present invention include branching segments 74 extending circumferentially, such that they extend through the sealing strip 42 from a coolant plenum formed within the sealing strip 42 (i.e., the cutting tooth segment 73). Given this configuration, the coolant discharged in this manner cools surfaces and areas within the tip cover strip 41 and / or the blade 25 that are particularly difficult to cool but require it. These areas may include the contact edges forming the contact interface between adjacent tip cover strips 41, as well as the edges of the sealing strip 42.Thus, in general, the branching segments 74 can extend through the interior of the sealing strip 42 to the rotationally forward and / or rotationally rear portions of the tip cover 41 and / or outer regions of the blade 25. According to exemplary embodiments, the branching channels 74 can extend, as shown, from the coolant plenum or cutting tooth segment 73 to outlet openings 75 formed on the rotating leading edge 62 and / or the rotating trailing edge 63 of the sealing strip 42. According to other embodiments, these branching channels 74 can be angled internally to connect with outlet openings 75 formed on the rotating leading or trailing edges 46 of the tip cover 41, which may contain the rotating leading and trailing contact edges 52, 53 that constitute the contact interface.Such internal inclined branching segments 74 can be configured to extend further inwards, so that outlet openings 75 are formed through the inner surface 45 of the tip cover 41, the inner rounding region 49, and / or the outer surfaces of the blade 25. Accordingly, in certain preferred embodiments, the inwardly angled branching segments 74 can be configured to extend through the inner rounding region 49, which may include the inner pressure rounding region, the inner suction rounding region, or both. In such cases, the outlet openings 75 can be located on the pressure side 26 and / or the suction side 27 of the blade 25.

[0065] As in the Fig. 12 and Fig. As shown in Figure 13, the branching segments 74 can contain several individual segments extending circumferentially such that at least one of the branching segments 74 extends through the sealing rail 42 in the direction of rotation and at least one extends through the sealing rail 42 away from the direction of rotation. As is understood, the branching segments 74 oriented in this way can run parallel to the longitudinal axis of the sealing rail 42. As shown, the circumferentially extending branching segments 74 can be angled or inclined inwards. The target surfaces of the circumferentially extending branching segments 74 can include the inner surface 45 of the top cover strip 41.Alternatively, the target surfaces of the circumferentially extending branching segments 74 can include the surfaces related to the inner fillet area 49, which may include the inner pressure-side fillet area, the inner suction-side fillet area, or both. As in the . Fig. 13, Fig. 14 to Fig. As shown in Figure 15, the circumferentially extending branching segments 74 can extend to outlet openings 75, which are formed on target surfaces that include one or both of the rotating front edge 62 and the rotating rear edge 63 of the sealing rail 42. Outlet openings 75 formed on the front and rear sides 56, 57 are also possible.

[0066] According to alternative embodiments, as described in the Fig. 16 and Fig.As shown in Figure 17, the branching segments 74 can have an outlet opening 75 configured as a near-surface fork 76. As used here, a near-surface fork 76 includes a division or bifurcation of a branching segment 74 of a coolant channel immediately before reaching the outer surface of the rotor blade. The near-surface fork 76 can divide into two or more of the coolant channels. Each of these channels, here referred to as tines 77, can extend from the division to separate and independent outlet openings 75, which can be used to distribute the coolant from the coolant channel over a larger area and interior than would otherwise be possible if the channel had only a single outlet opening 75.In this way, the coolant moving through the branching segments 74 can be distributed over and through a larger area and a larger near-surface interior region before being discharged into the working fluid stream. Since such near-surface interior regions represent highly effective areas through which a coolant must be circulated, the near-surface branching 76 can increase performance and cooling efficiency.

[0067] As mentioned, the near-surface fork 76 also allows coolant to be discharged over a larger external area. This larger area can be contained solely within each of the target surfaces already discussed, or alternatively, the near-surface fork 76 can be configured to include outlet openings 75 that cover or span some of the target surfaces. Thus, for example, according to exemplary configurations, the near-surface fork 76 can include prongs 77 connected to two or more outlets 75 that are formed entirely on either the rotating front edge 62 of the sealing rail 42 or the rotating rear edge 63 of the sealing rail 42.This means that the near-surface fork 76 can include a first prong 77 and a second prong 77 connected to outlet openings 75, both formed on the rotating front edge 62 and / or both formed on the rotating rear edge 63 of the sealing strip 42. According to the alternative configuration, the near-surface fork 76 can, for example, include a first prong 77 connected to an outlet opening 75 formed on the edge 46 of the tip cover strip 41, and a second prong 77 connected to an outlet opening 75 formed on the inner surface 45 of the tip cover strip 41.According to another example, the near-surface fork 76 can, for instance, include a first prong 77 connected to an outlet opening 75 formed on either the rotating front edge 62 or the rotating rear edge 63 of the sealing rail 42, and a second prong 77 connected to an outlet opening 75 formed on either the front 56 or the rear 57 of the sealing rail 42. Other configurations, some of which are shown, are also possible.

[0068] A turbine rotor blade comprising: a blade defined between a pressure side and a suction side; a tip shroud comprising a sealing strip projecting from an outer surface and a cutting tooth formed thereon; and a cooling configuration comprising a cooling channel for receiving and conveying a coolant through an interior of the rotor blade. The cooling channel may include fluidically connected segments in which: a feed segment extends radially through the blade; a cutting tooth segment is formed within the cutting tooth of the sealing strip; and branching segments are formed within at least one of the tip shroud and an outer region of the blade.Each of the branching segments can extend between an upstream opening connected to the incisor segment and an outlet opening formed on a target surface, such that the branching segment divides a target interior into two.

Claims

[1] Rotor blade (16) for a turbine (12) of a gas turbine (10) which contains: a blade (25) defined between a concave pressure side (26) and a laterally opposite convex suction side (27), wherein the pressure side (26) and the suction side (27) extend axially between an inflow and an opposite outflow edge (28, 29) and radially between an outer tip (31) and an inner end attached to a foot (21) configured to couple the rotor blade (16) to a rotor disk; a tip cover band (41) which is connected to the outer tip (31) of the blade (25), wherein the tip cover band (41) has a sealing rail (42) projecting from an outer surface (44) and a cutting tooth (43) formed on the sealing rail (42); a cooling configuration (36) comprising a cooling channel for receiving and conveying a coolant through an interior of the rotor blade (16), wherein the cooling channel has fluidically connected segments in which: a feed segment (72) extends radially through the blade (25); a plenum segment (73) is formed within the sealing rail (42); and Branching segments (74) are formed within at least one of the tip cover band (41) and an outer area of ​​the blade (25); wherein each of the branching segments (74) extends between an upstream opening connected to the plenum segment (73) and an outlet opening (75) formed on a target surface, and divides a target interior area in between; where: the plenum segment (73) has an incisor segment formed within the incisor (43) of the sealing rail (42); the tip cover band (41) has a component extending axially and circumferentially, which is held by the outer tip (31) of the blade (25); the top cover strip (41) has an inner surface (45) opposite the outer surface (44) over a radial thickness of the top cover strip (41), and an edge (46) connecting the inner surface (45) with the outer surface (44), which defines an outer profile of the top cover strip (41); the sealing strip (42) projects radially outwards from the outer surface (44) of the tip cover strip (41) and extends circumferentially in a direction of rotation of the running blade (16); and the incisor (43) has a circumferential section of the sealing rail (42) which is axially widened, the axial widening extending radially between the outer surface (44) of the tip cover strip (41) and an outer edge (59) of the sealing rail (42); wherein the guide vane (16) has an inner rounding area (49) which is configured to transition smoothly between a surface of the blade (25) and the inner surface (45) of the tip cover strip (41), and an outer rounding area (48) which is configured to transition smoothly between the outer surface (44) of the tip cover strip (41) and a front (56) of the sealing rail (42) and between the outer surface (44) of the tip cover strip (41) and a rear (57) of the sealing rail (42); wherein the tip cover band (41) comprises: a front part (68) extending forward from the sealing strip (42) to project above the leading edge (28) of the airfoil (25), a rear part (69) extending backward from the sealing strip (42) to project above the trailing edge (29) of the airfoil (25), a pressure part (66) projecting from and projecting above the pressure side (26) of the airfoil (25), a suction part (67) projecting from and projecting above the suction side (27) of the airfoil (25), and an airfoil part (65) defined within a contour of a profile of the airfoil (25) projecting radially through the tip cover band (41); wherein the sealing rail (42) comprises opposite rail sides, where the front (56) of the sealing rail (42) corresponds to the forward direction of the turbine (12) and the rear (57) of the sealing rail (42) corresponds to the reverse direction of the turbine (12); wherein the sealing rail (42) comprises an approximately rectangular profile such that the front (56) and the back (57) of the sealing rail (42) are connected along narrow edges which include: opposite outer and inner edges and rotational front and rotational rear edges (62, 63) wherein the rotational front edge (62) leads the rotational rear edge (63) with respect to the direction of rotation of the impeller blade (16); wherein the target surfaces include at least two of the following: the pressure side (26) of the blade (25); the suction side (27) of the blade (25); the surface corresponding to the inner fillet area (49); the surface corresponding to the outer fillet area (48); the inner surface (45) of the tip cover strip (41); the edge (46) of the tip cover strip (41); the rotation leading edge (62) of the sealing strip (42); the rotation trailing edge (63) of the sealing strip (42); the front (56) of the sealing strip (42); and the rear (57) of the sealing strip (42); wherein the target interior areas comprise at least two of the following: the outer area of ​​the blade (25); the inner rounding area (49); the outer rounding area (48); the leading part (68) of the tip cover (41); the trailing part (69) of the tip cover (41); the pressure part (66) of the tip cover (41); the suction part (67) of the tip cover (41); the blade part (65) of the tip cover (41); and the sealing strip (42); wherein the branching segments (74) contain several branching segments (74) which extend in the circumferential direction such that at least one extends in the direction of rotation and at least one extends away from the direction of rotation; wherein at least one of the several circumferentially extending branching segments (74) contains the outlet opening (75) which is configured to include a near-surface fork (76), wherein the near-surface fork (76) comprises tines (77) which are connected to corresponding individual outlet openings (75) formed on at least two of the target surfaces. [2] Running vane (16) according to claim 1, wherein each is arranged at a steep angle to the outer surface (44) of the tip cover strip (41) from the front (56) and the rear (57) of the sealing rail (42). [3] Guide vane (16) according to claim 1, wherein at the opposite outer and inner edges of the sealing rail (42) the inner edge is defined at the connection which the sealing rail (42) makes with the outer surface (44) of the tip cover strip (41), and the outer edge is offset to the outer surface (44) of the tip cover strip (41) by a radial height of the sealing rail (42). [4] Guide vane (16) according to claim 3, wherein: the incisor segment has: a plenum that is completely contained within the incisor (43); a position in a central circumferential area of ​​the sealing rail (42); a flow cross-section that is larger than the flow cross-section of each of the branching segments branching off from it (74); and a flow cross-section that is larger than a flow cross-section of the associated supply segment (72); and the feed segment (72) has: an upstream end formed by the foot (21) of the impeller blade (16), at which the supply segment (72) is fluidly connected to an air source, and a downstream end which is fluidly connected to the cutting tooth segment; a radially oriented linear channel through the blade (25); and the branching segments (74) have outlet openings (75) which communicate with the working fluid flow path in terms of flow. [5] Impeller blade (16) according to one of the preceding claims, wherein flow cross-sections of the branching segments (74) are dimensioned according to a desired metering of the coolant flow through the target interior areas; and wherein: an inner pressure rounding area has the inner rounding area (49) between the pressure side (26) of the blade (25) and the inner surface (45) of the tip cover band (41); an inner suction rounding area has the inner rounding area (49) between the suction side (27) of the blade (25) and the inner surface (45) of the tip cover band (41); a front outer rounding area has the outer rounding area (48) between the front (56) of the sealing rail (42) and the outer surface (44) of the top cover strip (41); and a rear outer rounding area has the outer rounding area (48) between the rear (57) of the sealing rail (42) and the outer surface (44) of the top cover strip (41). [6] Guide vane (16) according to any of the preceding claims, wherein: the outer profile of the tip cover strip (41) has a notched section for engaging a tip cover strip (41) of an adjacent rotor blade (16) when installed in a series of identically configured rotor blades (16); and the sealing rail (42) extends over substantially the entire circumferential length of the outer surface (44) of the top cover strip (41), wherein the circumferential length of the top cover strip (41) has a length of the top cover strip (41) in the direction of rotation. [7] Gas turbine (10) with a series of rotor blades (16) in a turbine (12), wherein the series of rotor blades (16) comprises several rotor blades (16) according to one of the preceding claims.

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