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EP3473808B1 - Blade for an internally cooled turbine blade and method for producing same - Google Patents

Blade for an internally cooled turbine blade and method for producing same Download PDF

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Publication number
EP3473808B1
EP3473808B1 EP17197244.1A EP17197244A EP3473808B1 EP 3473808 B1 EP3473808 B1 EP 3473808B1 EP 17197244 A EP17197244 A EP 17197244A EP 3473808 B1 EP3473808 B1 EP 3473808B1
Authority
EP
European Patent Office
Prior art keywords
rib
tip
cooling hole
blade airfoil
cooling
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP17197244.1A
Other languages
German (de)
French (fr)
Other versions
EP3473808A1 (en
Inventor
Tobias Buchal
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens Energy Global GmbH and Co KG
Original Assignee
Siemens AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Siemens AG filed Critical Siemens AG
Priority to EP17197244.1A priority Critical patent/EP3473808B1/en
Priority to US16/145,792 priority patent/US10746027B2/en
Publication of EP3473808A1 publication Critical patent/EP3473808A1/en
Application granted granted Critical
Publication of EP3473808B1 publication Critical patent/EP3473808B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/18—Hollow blades, i.e. blades with cooling or heating channels or cavities; Heating, heat-insulating or cooling means on blades
    • F01D5/186—Film cooling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
    • F01D11/10—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator using sealing fluid, e.g. steam
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/08—Cooling; Heating; Heat-insulation
    • F01D25/12—Cooling
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D25/00—Component parts, details, or accessories, not provided for in, or of interest apart from, other groups
    • F01D25/32—Collecting of condensation water; Drainage ; Removing solid particles
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D5/00—Blades; Blade-carrying members; Heating, heat-insulating, cooling or antivibration means on the blades or the members
    • F01D5/12—Blades
    • F01D5/14—Form or construction
    • F01D5/20—Specially-shaped blade tips to seal space between tips and stator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D9/00—Stators
    • F01D9/02—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles
    • F01D9/04—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector
    • F01D9/041—Nozzles; Nozzle boxes; Stator blades; Guide conduits, e.g. individual nozzles forming ring or sector using blades
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01D—NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES
    • F01D11/00—Preventing or minimising internal leakage of working-fluid, e.g. between stages
    • F01D11/08—Preventing or minimising internal leakage of working-fluid, e.g. between stages for sealing space between rotor blade tips and stator
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2220/00—Application
    • F05D2220/30—Application in turbines
    • F05D2220/32—Application in turbines in gas turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2230/00—Manufacture
    • F05D2230/10—Manufacture by removing material
    • F05D2230/13—Manufacture by removing material using lasers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/10—Stators
    • F05D2240/12—Fluid guiding means, e.g. vanes
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2240/00—Components
    • F05D2240/20—Rotors
    • F05D2240/24—Rotors for turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00—Function
    • F05D2260/20—Heat transfer, e.g. cooling
    • F05D2260/202—Heat transfer, e.g. cooling by film cooling

Definitions

  • the invention relates to an airfoil for an internally cooled turbine blade according to the preamble of claim 1.
  • the invention further relates to a method for producing an airfoil.
  • Turbine blades and their airfoils have long been known from the extensive state of the art.
  • the turbine blades can withstand the high temperatures that occur during operation, they are designed to be coolable.
  • they have a cavity inside, through which a coolant, usually cooling air, can flow during operation.
  • a coolant usually cooling air
  • the cooling air heated up when flowing through is blown out and mixed into the working fluid of the gas turbine. If the cooling fluid is cooling air, it is taken from the compressor belonging to the gas turbine.
  • the compressor air can still contain dust and dirt particles which can accumulate in the compressor when it flows through and also when it flows through the turbine blade.
  • specially shaped inlets for cooling air openings can also be used.
  • an ovalization of the inlet area of the cooling air hole means that a particle carried along cannot penetrate into the hole.
  • film cooling holes with a diffuser-like opening can also be arranged between the contact edges in the tip base in such a way that a cooling film can form over the inner sides of the contact edge.
  • these film cooling holes have comparatively small inflow cross sections, they can tend to become blocked if dust particles are carried in the cooling air.
  • conventional cooling air holes can also lead the cooling air to the brushing edge.
  • the object of the invention is therefore to provide a blade for an internally cooled turbine blade, the cooling holes of which have a lower tendency to contaminate particles carried in the cooling air.
  • Another object of the invention is to provide a method by means of which the inventive blades can be produced simply and with greater reliability than before.
  • this first-mentioned object is achieved by an airfoil according to claim 1 and the second-mentioned object by a manufacturing method according to claim 11.
  • the present invention proposes that in the case of an airfoil for an internally cooled turbine blade, comprising a suction side wall and a pressure side wall, a cavity extending at least from a common front edge to a common rear edge and in a span direction from a foot end to a head end partially enclose, the head end comprising a tip wall delimiting the cavity on the head side, in which at least one cooling hole, preferably a plurality of cooling holes is provided for discharging cooling fluid which can flow inside, in the cavity at least one extending from the tip wall in the direction of the foot side End-extending rib, preferably a plurality of such ribs, protrudes from the inner surface of the suction-side wall surrounding this rib or from the inner surface of the pressure-side wall surrounding this rib, and that one - with respect to the ku hlfluid - inflow opening of the at least one cooling hole in the rib in question opens laterally.
  • the invention is based on the knowledge that the lateral arrangement of the inflow opening of the cooling hole in one rib protruding from the inner surface of the side wall significantly impedes the inflow of particles carried in the cooling air. Due to the difficult inflow of particles into the cooling hole, the risk of clogging is reduced, which can increase the service life of the airfoil and a turbine blade equipped with it.
  • the lateral arrangement of the inflow opening in the rib in the case of straight cooling holes can preferably be realized if a channel axis of the cooling hole is arranged at an incline with respect to the longitudinal direction of the rib between the head-side and foot-side ends. It is irrelevant whether the cooling hole or the rib is strictly radial.
  • the lateral arrangement can be realized if the cooling hole along its channel axis is not straight, but curved. It is then sufficient if the cooling hole in the region of the inflow opening - ie immediately downstream thereof - is inclined with respect to the local longitudinal extent of the rib.
  • Such curved cooling holes can easily be produced by eroding.
  • the orientation of the rib is of minor relevance. In both cases, a grinding or oblique cut results with the formation of an elliptical inflow opening.
  • the inflow opening particularly preferably has an elliptical shape with a smaller axis and a larger axis, the smaller axis being smaller than the diameter of the remaining cooling hole.
  • Such an inflow opening can be produced in the airfoil or in the turbine blade by eroding or by laser drilling. Due to the further reduced size of the inflow opening, particles which are very similar or larger to the diameter of the remaining cooling hole do not get into the cooling hole. Only those get into it that are so small that they are discharged again with the cooling fluid without adhering to them. This reduces the risk of the cooling hole becoming blocked.
  • the rib in question has a curved contour in a cross-sectional plane normal to the span direction, with a - in relation to the remaining inner surface - maximum rib height H, the inflow-side end of the cooling hole in question being arranged to the side of the location of the maximum rib height .
  • the rib can also have an angular, for example triangular or rectangular, contour instead of the curved contour.
  • a contour for the inflow opening can be achieved by drilling the cooling hole, which contour resembles an employed ellipse.
  • the longer axis of the ellipse is arranged parallel or at an acute angle to the inner surface of the side wall in question, but in the surface of the rib.
  • a comparatively narrow inlet slot can be provided to achieve a comparatively large inflow cross section, the shorter axis of which is chosen to be smaller than the diameter of particles typically carried in the cooling air. The risk of constipation can therefore be reduced.
  • the rib in question is further preferably inclined from its head-side end to its foot-side end in the direction of the front edge or in the direction of the rear edge.
  • the rib in question preferably extends in a straight line from its head-side end to its foot-side end, the longitudinal extension of the rib has an angle greater than 0 °, for example 25 °, with respect to the span direction. Due to the inclined or inclined arrangement, the problem of the exact axial positioning of the cooling hole to be drilled with respect to the rib can be reduced in particular. If there is an axial misalignment of the rib due to manufacturing-related casting tolerances, then lengthen or the length of the drilled cooling hole to be grasped is shortened.
  • the cavity adjoining the rib in question is such that its essential coolant supply is arranged on that side of the rib in question which faces away from the surface of the rib which has the inflow-side end of the cooling hole.
  • the relevant partial cavity of the airfoil, in which the relevant rib is arranged is supplied with coolant at a specific position.
  • the rib in question is located downstream of this specific position of the coolant supply, the upstream end of the cooling hole being arranged on the side of the rib which is opposite the incoming cooling air flow; the inflow opening is arranged in the lee of the rib in question.
  • At least one sealing tip is arranged on the outwardly facing surface of the tip wall, with the one in question being further preferred Cooling hole extends at least partially, preferably completely, through said sealing tip.
  • sealing tips can be provided which, despite their comparatively small wall thickness, can be internally cooled.
  • the wall thicknesses of such sealing tips can have a size of approximately 2 mm, the cooling holes being able to have a diameter of 1.0 mm and smaller.
  • the following goals are achieved with the invention:
  • the cooling hole By producing the cooling hole by means of laser drilling or eroding, the projected diameter of the cooling hole in the inflow region can also be kept smaller than downstream of it or in the outlet region. In this way, the length of the shorter axis of the ellipse can be reduced compared to the diameter of a round cooling hole.
  • pairs of rib and cooling hole according to the invention can be applied to both side walls of the airfoil. It is also a matter of course to manufacture such blades or turbine blades by means of additive processes, for example selective laser melting or the like.
  • FIG. 1 shows a turbine blade 10 in a perspective view.
  • the turbine blade 10 is in accordance with Figure 1 designed as a moving blade. It comprises a fir-tree-shaped blade root 12 and a platform 14 arranged thereon.
  • the airfoil 16 comprises a suction side wall 22 and a pressure side wall 24. Relative to a hot gas flowing around the airfoil 16, these walls extend from a front edge 18 to a rear edge 20.
  • a plurality of openings 28 for blowing out coolant are provided, which are separated from one another by webs 30 arranged therebetween.
  • the airfoil 16 extends along a span direction, which coincides with a radial direction of a turbine, from a foot-side end 26 to a head-side end 27.
  • the latter is also known as the blade tip.
  • the span direction coincides with the radial direction R of the gas turbine.
  • Figure 2 shows a sectional view through the airfoil 16 according to the section line II - II as the first embodiment of an airfoil 16 according to the invention
  • Figure 2 only the radially outer end of the airfoil 16 with respect to the span or radial direction R of the gas turbine, ie the airfoil tip, is shown.
  • the airfoil 1 Installed in a gas turbine, the airfoil 1 extends in the radial direction R.
  • Further axes of the gas turbine are denoted by A and U, where A stands for the axial direction and U represents the circumferential direction. These are used below, if necessary, to describe the arrangement more easily.
  • the airfoil 16 has a tip wall 34 at the head-side end 27, which delimits a cavity 32 towards the outside.
  • the tip wall 34 is essentially at a right angle to the suction side wall 22 and merges into it.
  • a rib 38 is arranged on an inner surface 40 of the suction side wall 22 facing the cavity 32.
  • the rib 38 extends in a straight line from its end 46 arranged on the head side to its end 44 arranged on the foot side.
  • a further rib 39 extending in the axial direction is provided radially inward at a distance from the rib 38 in order to deflect particles in the event of a radially occurring cooling flow.
  • a sealing tip 48 is also arranged on the radially outward-facing surface 52 of the tip wall 34 and is part of this.
  • Such sealing tips also known as “squealer tips” in English, are usually perceived as radial extensions of the side walls 22, 24 of the turbine blade 10. They serve to reduce a gap between the blade tip and the hot gas path limitation of the gas turbine opposite this.
  • the sealing tips 48 can be arranged in a stepless manner with respect to the outer side surfaces of the suction side wall 22 or pressure side wall 24, as shown.
  • a cooling hole 36 extends through the tip wall 34 together with the sealing tip 48 into the rib 38.
  • the cooling hole 36 has an inflow opening 42 for a cooling fluid.
  • a cooling fluid that can be supplied to the cavity 32 can flow into said opening 42, flow along the cooling hole 36 and exit at the outer end.
  • the cooling fluid cools the local area of the suction side wall 22, the tip wall 34 and in particular the sealing tip 48.
  • the cooling hole 36 does not necessarily have to extend through the sealing tip 48. According to an alternative embodiment, the cooling hole 36 can also end at the side of the sealing tip 48. For example, it can end on the hot gas side or also in the tip free space 39.
  • Figure 3 shows the top view of the interior of the blade tip according to the section line III-III Figure 2 .
  • the rib 38 is designed to be inclined with respect to the radial direction.
  • the rib 38 according to the exemplary embodiment shown here extends in a straight line from its head-side end 46 to its foot-side end 44.
  • the cooling hole 36 extending through the sealing tip 48, the tip wall 34 into the rib 38 is parallel to the radial direction R aligned, but inclined in the circumferential direction ( Fig. 2 ).
  • the outlined orientations of the cooling hole 36 and the rib 37 are not absolutely necessary, but rather in each case depending on the orientation of the aerodynamically curved airfoil in the space on the one hand and the location of the cooling hole on the other hand.
  • a channel axis 37 of the cooling hole 36 is preferably inclined at an obtuse angle in the region of the inflow opening 42 with respect to the longitudinal extent of the rib 38.
  • the cooling hole 36 for example, as well as the rib 38, can be inclined in the circumferential direction U and / or in the axial direction A.
  • FIG Figure 5 A cooling hole 36 inclined in the axial direction is shown in FIG Figure 5 shown and opens into the rib 38, which is curved in the radial direction Figure 5
  • Figure 4 shows the section through the blade tip-side end 27 of the blade 16 according to the section line IV-IV Figure 2 .
  • two ribs 38 according to the invention are provided on the suction side, of which the first asymmetrically curved protrudes from the inner surface 40 of the suction side wall 22.
  • the second of the two ribs 38 according to the invention is triangular in shape. It is not necessary for the rib to protrude from the inner surface like turbulators, the transition from the inner surface 40 to the side surface of the rib 38 can also be designed in a stepless manner and thus with low aerodynamic losses, particularly on its upstream side.
  • the cooling holes 36 open into one of the side surfaces of the ribs 38.
  • the position of the opening 42 is in that side surface of the rib 38 which is arranged away from a maximum rib height H.
  • the rib height H is based on the remaining inner surface 40 of the suction-side wall 22.
  • a cooling fluid preferably cooling air
  • the cooling fluid consequently flows through the cavity 32 and the cooling fluid has a predetermined main flow direction 50 due to the topology of the cavity 32 and the position of a cooling air supply and the position of adjacent outflow channels.
  • This main flow direction is to be determined in the immediate vicinity of the rib 38 according to the invention. Since the cooling fluid can never be completely free of dirt particles, it is advantageous if the inflow opening 42 of the cooling hole 36 is arranged on that side of the rib 38 in question which faces away from the cooling fluid flowing into the rib in question.
  • the inflow opening 42 of the cooling hole 36 is more or less in the slipstream - in the lee - of the maximum fin height H. From the cooling fluid entrained particles are directed into a flow path due to the shape of the rib 38, in which they move away with increasing distance from the inner surfaces of the side walls 22, 24 to the location of the maximum rib height H. Then they flow due to their inertia and that of the flow direction facing away from the inflow opening 42; they can only flow into the cooling hole 36 under difficult conditions. As a result, air with less particles - compared to the prior art - flows into the cooling holes 36 and thus the risk of clogging is reduced. This enables the use of cooling holes 36 with a particularly small diameter, for example also smaller than one millimeter, with a reduced risk of the inflow openings 42 or the cooling holes 36 being blocked by entrained particles.
  • the inflow opening 42 of the cooling holes 36 opening into the rib 38 is not circular, but rather is elliptically inclined with one longer axis and a shorter axis. Even this would make it difficult for particles flowing in cooling air to flow in a straight line toward cooling hole 36 to flow into cooling hole 36 in question.
  • the cooling hole 36 can be subsequently produced by drilling.
  • the orientation of the rib 38 which is inclined with respect to the radial direction R is particularly advantageous.
  • the inclined rib 38 offers ( Fig. 3 ) the advantage that the cooling hole 36 can be located in a comparatively large axial section AB.
  • the cooling hole 36 has an elliptically shaped inflow opening 42, which is always arranged on the side lying downstream of the incoming cooling fluid in the lee. This improves the manufacturability of such a turbine blade 10, since the section AB in which the cooling hole is to be drilled is comparatively large and therefore easier to hit.
  • the invention provides an airfoil 16 for an internally cooled turbine blade 10, comprising a suction-side wall 22 and a pressure-side wall 24, which extend from a common front edge 18 to a common rear edge 20 and in a span direction from a foot-side end 26 to a head-side End 27 extends at least partially enclosing a cavity, the head-side end 27 comprising a tip wall 34 delimiting the cavity 32 on the head side, in which at least one cooling hole 36, preferably a plurality of cooling holes 36 is provided for discharging cooling fluid that can flow inside.
  • a turbine blade in which the risk of clogging of cooling holes is reduced and the service life of the turbine blade 10 can be extended, it is proposed that in the cavity 32 preferably at least one rib extending from the tip wall 34 towards the foot-side end 42 is preferred a plurality of such ribs 38, from which this rib surrounding inner surfaces 40 of the suction side wall 22 and / or the inner surface 40 of the pressure side wall 24 protrudes and that - in relation to the cooling fluid - inflow opening 42 of the at least one cooling hole 36 opens laterally into the relevant rib 38 .

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Turbine Rotor Nozzle Sealing (AREA)

Description

Die Erfindung betrifft ein Schaufelblatt für eine innengekühlte Turbinenlaufschaufel gemäß dem Oberbegriff des Anspruchs 1. Weiter betrifft die Erfindung ein Verfahren zur Herstellung eines Schaufelblatts.The invention relates to an airfoil for an internally cooled turbine blade according to the preamble of claim 1. The invention further relates to a method for producing an airfoil.

Turbinenschaufeln und deren Schaufelblätter sind aus dem umfangreich vorhandenen Stand der Technik längstens bekannt.Turbine blades and their airfoils have long been known from the extensive state of the art.

Damit die Turbinenschaufeln den im Betrieb auftretenden hohen Temperaturen dauerhaft Stand halten können, sind diese kühlbar ausgestaltet. Sie weisen dazu im Inneren einen Hohlraum auf, der während des Betriebs von einem Kühlmittel, zumeist Kühlluft, durchströmt werden kann. Nach Durchströmen der Turbinenschaufel und insbesondere dessen Schaufelblatt wird die beim Durchströmen aufgeheizte Kühlluft in das Arbeitsfluid der Gasturbine ausgeblasen und diesem untergemischt. Sofern es sich bei dem Kühlfluid um Kühlluft handelt, wird dieses dem zur Gasturbine zugehörigen Verdichter entnommen. Trotz umfangreicher Maßnahmen zur Reinhaltung der Verdichterluft und auch insbesondere der Kühlluft kann diese weiterhin Staub- und Schmutzpartikel enthalten, die sich beim Durchströmen des Verdichters und auch beim Durchströmen der Turbinenschaufel darin ablagern können.So that the turbine blades can withstand the high temperatures that occur during operation, they are designed to be coolable. For this purpose, they have a cavity inside, through which a coolant, usually cooling air, can flow during operation. After flowing through the turbine blade and in particular its blade, the cooling air heated up when flowing through is blown out and mixed into the working fluid of the gas turbine. If the cooling fluid is cooling air, it is taken from the compressor belonging to the gas turbine. Despite extensive measures to keep the compressor air clean and in particular the cooling air, it can still contain dust and dirt particles which can accumulate in the compressor when it flows through and also when it flows through the turbine blade.

Aus diesem Grunde sind moderne Konstruktionen von Turbinenschaufeln unter anderem auch darauf ausgelegt, Ablagerungen derartiger Staubpartikel an denjenigen Öffnungen zu vermeiden, durch welche die im Betrieb aufgeheizte Kühlluft ausgeblasen werden soll. Verstopfungen derartiger Kühlluftauslässe können dazu führen, dass die Kühlwirkung an dieser Stelle nur vermindert, wenn überhaupt eintritt. In diesem Fall werden dort die zulässigen Materialtemperaturen überschritten, so dass folglich sich die Materialeigenschaften an der überhitzen Stelle ändern. Dies ermöglicht die Bildung von lokalen Korrosionserscheinungen und Folgebeschädigungen, die schlimmstenfalls zu Bauteilversagen führen können.For this reason, modern turbine blade designs are designed, inter alia, to avoid deposits of such dust particles at the openings through which the cooling air heated during operation is to be blown out. Blockages of such cooling air outlets can have the effect that the cooling effect at this point only diminishes, if at all. In this case, the permissible material temperatures are there exceeded, so that consequently the material properties change at the overheated point. This enables the formation of local signs of corrosion and consequential damage, which in the worst case can lead to component failure.

Um dies zu verhindern ist es beispielsweise aus der EP 1 793 086 A2 bekannt, im Inneren der Kühlluftkanäle von Turbinenschaufeln Leitelemente vorzusehen, mit denen die in der Kühlluft mitgeführten Partikel umgelenkt werden. Dies verringert das Einströmen der Partikel in die Kühlluftauslässe.To prevent this, it is from the EP 1 793 086 A2 It is known to provide guide elements in the interior of the cooling air ducts of turbine blades with which the particles carried in the cooling air are deflected. This reduces the influx of particles into the cooling air outlets.

Gemäß einer alternativen Ausgestaltung, bekannt aus der EP 0 965 728 A2 , können auch speziell geformte Einläufe für Kühlluftöffnungen verwendet werden. Hierbei wird durch eine Ovalisierung des Einlaufbereichs des Kühlluftlochs erreicht, dass ein mitgeführtes Partikel nicht in das Loch eindringen kann.According to an alternative embodiment, known from the EP 0 965 728 A2 , specially shaped inlets for cooling air openings can also be used. In this case, an ovalization of the inlet area of the cooling air hole means that a particle carried along cannot penetrate into the hole.

Nachteilig ist, dass derartige Locheinläufe sich auf der Innenseite von üblicherweise im Feingussverfahren hergestellten Schaufeln nicht durch Bohren, sondern nur durch Gießen herstellen lassen. Aufgrund des Rückgriffs auf das Feingussverfahren weisen die Kühlluftlöcher jedoch dann einen vergleichsweise großen Durchmesser von mindestens etwa 2mm auf, was den Kühlluftverbrauch ungewünscht erhöht. Kleinere Durchmesser lassen sich nicht mit hinreichender Genauigkeit herstellen.It is disadvantageous that such hole inlets on the inside of blades which are usually produced using the precision casting process cannot be produced by drilling, but only by casting. Due to the recourse to the investment casting process, however, the cooling air holes then have a comparatively large diameter of at least approximately 2 mm, which undesirably increases the cooling air consumption. Smaller diameters cannot be manufactured with sufficient accuracy.

Darüber hinaus ist es beispielsweise aus der EP 1 793 087 A1 bekannt, an den Schaufelspitzen von Turbinenlaufschaufeln sogenannte Staublöcher anzuordnen. Diese Löcher sind im Spitzenbereich meist mittig zwischen Saug- und Druckseite angeordnet und von vergleichsweise großen Durchmesser. Dann besteht freilich nur eine sehr geringe Verstopfungsgefahr, allerdings erhöht sich durch diese der Kühlluftverbrauch. Ist deren Durchmesser dagegen reduziert, beispielsweise um Kühlluft einzusparen, so droht die Verstopfung mit den besagten Nachteilen. Ungeachtet dessen sind eine Vielzahl von Lösungen zur Kühlung der Schaufelspitzen von Turbinenlaufschaufeln bekannt. So offenbart beispielsweise die US 2017/0159450 A1 unterhalb der äußersten Schaufelspitzenposition in der Druckseite angeordnete Filmkühlöffnungen zur Kühlung der sich daran radial anschließenden Anstreifkante. Gemäß einer alternativen Ausführungen können Filmkühllöcher mit einer diffusorartigen Öffnung auch zwischen den Anstreifkanten im Spitzenboden derart angeordnet sein, dass sich ein Kühlfilm über die Innenseiten der Anstreifkante ausbilden kann. Weil diese Filmkühllöcher jedoch vergleichsweise geringe Einströmquerschnitte aufweisen, können diese zu Verstopfungen neigen, wenn in der Kühlluft Staubpartikel mitgeführt werden. Gemäß einer Alternative nach US 2012/03083921 A1 können anstelle von diffusorartigen Filmkühlöffnungen auch konventionelle Kühlluftbohrungen die Kühlluft zu den Anstreifkante führen.In addition, it is for example from the EP 1 793 087 A1 known to arrange so-called dust holes on the blade tips of turbine blades. These holes are usually arranged in the center between the suction and pressure side and are of a comparatively large diameter. Then there is of course only a very low risk of clogging, but this increases the consumption of cooling air. However, if their diameter is reduced, for example by Saving cooling air threatens constipation with the disadvantages mentioned. Regardless, a variety of solutions for cooling the blade tips of turbine blades are known. For example, the US 2017/0159450 A1 Film cooling openings arranged below the outermost blade tip position in the pressure side for cooling the scraping edge adjoining it radially. According to an alternative embodiment, film cooling holes with a diffuser-like opening can also be arranged between the contact edges in the tip base in such a way that a cooling film can form over the inner sides of the contact edge. However, because these film cooling holes have comparatively small inflow cross sections, they can tend to become blocked if dust particles are carried in the cooling air. According to an alternative US 2012/03083921 A1 Instead of diffuser-like film cooling openings, conventional cooling air holes can also lead the cooling air to the brushing edge.

Aufgabe der Erfindung ist daher die Bereitstellung eines Schaufelblatts für eine innengekühlte Turbinenlaufschaufel, deren Kühllöcher eine geringere Neigung zur Verschmutzung von in der Kühlluft mitgeführten Partikeln aufweist. Weitere Aufgabe der Erfindung ist die Angabe eines Verfahrens, mittels dem sich erfindungsgemäße Schaufelblätter einfach und mit vergrößerter Zuverlässigkeit als bisher herstellen lassen.The object of the invention is therefore to provide a blade for an internally cooled turbine blade, the cooling holes of which have a lower tendency to contaminate particles carried in the cooling air. Another object of the invention is to provide a method by means of which the inventive blades can be produced simply and with greater reliability than before.

Diese erstgenannte Aufgabe wird erfindungsgemäß durch ein Schaufelblatt nach Anspruch 1 gelöst und die zweitgenannte Aufgabe durch ein Herstellverfahren gemäß Anspruch 11.According to the invention, this first-mentioned object is achieved by an airfoil according to claim 1 and the second-mentioned object by a manufacturing method according to claim 11.

Vorteilhafte Weiterbildungen der erfindungsgemäßen Vorrichtung sind jeweils Gegenstand abhängiger Unteransprüche sowie der nachfolgenden Beschreibung.Advantageous developments of the device according to the invention are the subject of dependent subclaims and the following description.

Die vorliegende Erfindung schlägt vor, dass bei einem Schaufelblatt für eine innengekühlte Turbinenlaufschaufel, umfassend eine saugseitige Seitenwand und eine druckseitige Seitenwand, die von einer gemeinsamen Vorderkante zu einer gemeinsamen Hinterkante und in einer Spannweiterichtung von einem fußseitigen Ende zu einem kopfseitigen Ende sich erstreckend einen Hohlraum zumindest teilweise umschließen, wobei das kopfseitige Ende eine den Hohlraum kopfseitig begrenzende Spitzenwand umfasst, in welcher zumindest ein Kühlloch, vorzugsweise mehrere Kühllöcher zum Ausleiten von im Inneren strömbaren Kühlfluid vorgesehen ist bzw. sind, im Hohlraum zumindest eine sich von der Spitzenwand aus in Richtung des fußseitigen Endes erstreckende Rippe, vorzugsweise mehrere derartige Rippen, von der diese Rippe umgebenden Innenfläche der saugseitigen Seitenwand bzw. von der diese Rippe umgebenden Innenfläche der druckseitigen Seitenwand hervorsteht bzw. hervorstehen und dass eine - bezogen auf das Kühlfluid - Einströmöffnung des zumindest einen Kühllochs in der betreffenden Rippe seitlich mündet.The present invention proposes that in the case of an airfoil for an internally cooled turbine blade, comprising a suction side wall and a pressure side wall, a cavity extending at least from a common front edge to a common rear edge and in a span direction from a foot end to a head end partially enclose, the head end comprising a tip wall delimiting the cavity on the head side, in which at least one cooling hole, preferably a plurality of cooling holes is provided for discharging cooling fluid which can flow inside, in the cavity at least one extending from the tip wall in the direction of the foot side End-extending rib, preferably a plurality of such ribs, protrudes from the inner surface of the suction-side wall surrounding this rib or from the inner surface of the pressure-side wall surrounding this rib, and that one - with respect to the Kü hlfluid - inflow opening of the at least one cooling hole in the rib in question opens laterally.

Der Erfindung liegt die Erkenntnis zu Grunde, dass das seitliche Anordnen der Einströmöffnung des Kühlloches in einer von der Innenfläche der Seitenwand hervorstehenden Rippe das Einströmen von in der Kühlluft mitgeführten Partikeln signifikant erschwert. Aufgrund des erschwerten Einströmens von Partikeln in das Kühlloch sinkt die Gefahr einer Verstopfung, was die Standzeit des Schaufelblatts und einer damit ausgestatteten Turbinenlaufschaufel erhöhen kann.The invention is based on the knowledge that the lateral arrangement of the inflow opening of the cooling hole in one rib protruding from the inner surface of the side wall significantly impedes the inflow of particles carried in the cooling air. Due to the difficult inflow of particles into the cooling hole, the risk of clogging is reduced, which can increase the service life of the airfoil and a turbine blade equipped with it.

Bevorzugt lässt sich die seitliche Anordnung der Einströmöffnung in der Rippe bei geradlinig ausgeführten Kühllöchern realisieren, wenn eine Kanalachse des Kühllochs gegenüber der Längsrichtung der Rippe zwischen kopfseitigem und fußseitigem Ende geneigt angeordnet ist. Hierbei ist es unerheblich, ob das Kühlloch oder die Rippe streng radial ausgerichtet ist. Alternativ und oder ergänzend zur relativen Neigung zwischen Kühlloch und Rippe lässt sich die seitlich Anordnung realisieren, wenn das Kühlloch längs seiner Kanalachse nicht geradlinig, sondern gekrümmt ausgestaltet ist. Dann ist es ausreichend, wenn das Kühlloch im Bereich der Einströmöffnung - also unmittelbar stromab davon - gegenüber der lokalen Längserstreckung der Rippe geneigt ist. Derartige gekrümmte Kühllöcher lassen sich durch Erodieren einfach herstellen. Die Orientierung der Rippe ist hierbei von untergeordneter Relevanz. In beiden Fällen ergibt sich ein schleifender bzw. schiefer Schnitt unter Bildung einer ellipsenförmigen Einströmöffnung.The lateral arrangement of the inflow opening in the rib in the case of straight cooling holes can preferably be realized if a channel axis of the cooling hole is arranged at an incline with respect to the longitudinal direction of the rib between the head-side and foot-side ends. It is irrelevant whether the cooling hole or the rib is strictly radial. As an alternative and or in addition to the relative inclination between the cooling hole and the rib, the lateral arrangement can be realized if the cooling hole along its channel axis is not straight, but curved. It is then sufficient if the cooling hole in the region of the inflow opening - ie immediately downstream thereof - is inclined with respect to the local longitudinal extent of the rib. Such curved cooling holes can easily be produced by eroding. The orientation of the rib is of minor relevance. In both cases, a grinding or oblique cut results with the formation of an elliptical inflow opening.

Besonders bevorzugt weist die Einströmöffnung eine Ellipsenform mit einer kleineren Achse und einer größeren Achse auf, wobei die kleinere Achse kleiner ist als der Durchmesser des restlichen Kühllochs. Eine derartige Einströmöffnung lässt sich in dem Schaufelblatt bzw. in der Turbinenschaufel durch Erodieren oder durch Laserbohren herstellen. Aufgrund der weiter verkleinerten Größe der Einströmöffnung gelangen Partikel, die dem Durchmesser des restlichen Kühllochs sehr ähnlich oder größer sind, nicht in das Kühlloch. Es gelangen nur solche darein, die derartig klein sind, dass sie ohne darin anzuhaften mit dem Kühlfluid wieder ausgetragen werden. Dies verringert die Gefahr einer Verstopfung des Kühllochs.The inflow opening particularly preferably has an elliptical shape with a smaller axis and a larger axis, the smaller axis being smaller than the diameter of the remaining cooling hole. Such an inflow opening can be produced in the airfoil or in the turbine blade by eroding or by laser drilling. Due to the further reduced size of the inflow opening, particles which are very similar or larger to the diameter of the remaining cooling hole do not get into the cooling hole. Only those get into it that are so small that they are discharged again with the cooling fluid without adhering to them. This reduces the risk of the cooling hole becoming blocked.

Gemäß einer weiteren besonders bevorzugten Ausgestaltung der Erfindung weist die betreffende Rippe in einer zur Spannweiterichtung normalen Querschnittsebene eine gewölbte Kontur mit einer - bezogen auf die restliche Innenfläche - maximalen Rippenhöhe H auf, wobei das einströmseitige Ende des betreffenden Kühllochs seitlich des Ortes der maximalen Rippenhöhe angeordnet ist. Alternativ zur ersten bevorzugten Ausgestaltung kann die Rippe anstelle der gewölbten Kontur auch eine eckige, beispielsweise dreieckige oder rechteckige Kontur aufweisen. Insbesondere in Verbindung mit der gewölbten Rippenkontur kann durch Bohren des Kühllochs eine Kontur für die Einströmöffnung erreicht werden, welche einer angestellten Ellipse gleicht. In Abhängigkeit von der tatsächlichen Orientierung des gebohrten Kühllochs und der Radial- und Axialerstreckung der Rippe sowie deren Querschnittskontur ist die längere Achse der Ellipse parallel oder spitzwinklig zur Innenfläche der betreffenden Seitenwand, jedoch in der Rippenoberfläche angeordnet. Aufgrund der elliptischen Einlaufkontur der Einströmöffnung kann unter Erreichung eines vergleichsweise großen Einströmquerschnitts ein vergleichsweise enger Einlassschlitz bereitgestellt werden, dessen kürzere Achse kleiner gewählt ist als der Durchmesser von typischerweise in der Kühlluft mitgeführten Partikeln. Die Gefahr einer Verstopfung kann mithin verringert werden.According to a further particularly preferred embodiment of the invention, the rib in question has a curved contour in a cross-sectional plane normal to the span direction, with a - in relation to the remaining inner surface - maximum rib height H, the inflow-side end of the cooling hole in question being arranged to the side of the location of the maximum rib height . As an alternative to the first preferred embodiment, the rib can also have an angular, for example triangular or rectangular, contour instead of the curved contour. Particularly in connection with the curved rib contour, a contour for the inflow opening can be achieved by drilling the cooling hole, which contour resembles an employed ellipse. Depending on the actual orientation of the drilled cooling hole and the radial and axial extent of the rib and its cross-sectional contour, the longer axis of the ellipse is arranged parallel or at an acute angle to the inner surface of the side wall in question, but in the surface of the rib. On account of the elliptical inlet contour of the inflow opening, a comparatively narrow inlet slot can be provided to achieve a comparatively large inflow cross section, the shorter axis of which is chosen to be smaller than the diameter of particles typically carried in the cooling air. The risk of constipation can therefore be reduced.

Weiter bevorzugt ist die betreffende Rippe ausgehend von ihrem kopfseitigen Ende zu ihrem fußseitig angeordneten Ende in Richtung zur Vorderkante oder in Richtung zur Hinterkante geneigt. Zwar erstreckt sich die betreffende Rippe vorzugsweise geradlinig von ihrem kopfseitigen Ende zu ihrem fußseitigen Ende, jedoch weist die Längserstreckung der Rippe gegenüber Spannweiterichtung einen Winkel größer 0°, beispielsweise 25° auf. Durch die angestellte bzw. schräge Anordnung kann insbesondere das Problem der exakten axialen Positionierung des zu bohrenden Kühlloches bezüglich der Rippe reduziert werden. Sollte es aufgrund von herstellungsbedingten Gusstoleranzen zu einem axialen Versatz der Rippe kommen, so verlängert oder verkürzt sich zwar die in Spannweite zu erfassende Länge des gebohrten Kühllochs. Dagegen bleibt aber dessen Eintrittsgeometrie, d.h. die Ellipsenform und auch die seitliche Lage der Einströmöffnung erhalten, was die Neigung zur Verstopfung des Kühlloches weiterhin gering hält. Mithin lässt sich mit dem genannten Merkmal trotz herstellungsbedingter Toleranzen des gegossenen Schaufelblattes ein größerer Bereich angeben, in dem das Kühlloch so gebohrt werden kann, dass es weiterhin in der Rippe seitlich mündet.The rib in question is further preferably inclined from its head-side end to its foot-side end in the direction of the front edge or in the direction of the rear edge. Although the rib in question preferably extends in a straight line from its head-side end to its foot-side end, the longitudinal extension of the rib has an angle greater than 0 °, for example 25 °, with respect to the span direction. Due to the inclined or inclined arrangement, the problem of the exact axial positioning of the cooling hole to be drilled with respect to the rib can be reduced in particular. If there is an axial misalignment of the rib due to manufacturing-related casting tolerances, then lengthen or the length of the drilled cooling hole to be grasped is shortened. In contrast, however, its inlet geometry, ie the elliptical shape and also the lateral position of the inflow opening, are retained, which furthermore keeps the tendency to block the cooling hole low. Thus, despite the manufacturing-related tolerances of the cast airfoil, a larger area can be specified with the mentioned feature in which the cooling hole can be drilled so that it continues to open laterally in the rib.

Darüber hinaus ist es von Vorteil, wenn der an die betreffende Rippe angrenzende Hohlraum dergestalt ist, dass dessen wesentliche Kühlmittelzufuhr auf derjenigen Seite der betreffenden Rippe angeordnet ist, welcher der das einströmseitige Ende des Kühllochs aufweisenden Oberfläche der Rippe abgewandt ist. Mit anderen Worten: der betreffende Teilhohlraum des Schaufelblattes, in dem die betreffende Rippe angeordnet ist, wird an einer bestimmten Position mit Kühlmittel gespeist. Die betreffende Rippe befindet sich stromab dieser bestimmten Position der Kühlmittelzufuhr, wobei das einströmseitige Ende des Kühlloches auf derjenigen Seite der Rippe angeordnet ist, die der ankommenden Kühlluftströmung gegenüberliegt; die Einströmöffnung ist im Lee der betreffenden Rippe angeordnet. In Verbindung mit der Tatsache, dass das einströmseitige Ende des betreffenden Kühllochs stromab der maximalen Erhebung der Rippe angeordnet ist, befindet sich das einströmseitige Ende im Windschatten. In dem Kühlmittel mitgeführte Partikel strömen somit entlang der Innenfläche der betreffenden Seitenwand zur Rippe, werden von dieser abgehoben und strömen dann aufgrund ihrer Massenträgheit zwangsweise über die Einströmöffnung des Kühllochs hinweg, ohne die Möglichkeit zu besitzen, in dieses einzutreten. Diese Ausgestaltung reduziert signifikant die Wahrscheinlichkeit der Verstopfung von Kühllöchern.In addition, it is advantageous if the cavity adjoining the rib in question is such that its essential coolant supply is arranged on that side of the rib in question which faces away from the surface of the rib which has the inflow-side end of the cooling hole. In other words: the relevant partial cavity of the airfoil, in which the relevant rib is arranged, is supplied with coolant at a specific position. The rib in question is located downstream of this specific position of the coolant supply, the upstream end of the cooling hole being arranged on the side of the rib which is opposite the incoming cooling air flow; the inflow opening is arranged in the lee of the rib in question. In connection with the fact that the upstream end of the cooling hole in question is arranged downstream of the maximum elevation of the rib, the upstream end is in the slipstream. Particles entrained in the coolant thus flow along the inner surface of the side wall in question to the rib, are lifted off the rib and then, due to their inertia, are forced to flow over the inflow opening of the cooling hole without being able to enter it. This design significantly reduces the likelihood of clogging of cooling holes.

Gemäß einer besonders bevorzugten Ausgestaltung ist an der nach außen weisenden Fläche der Spitzenwand zumindest eine Dichtspitze angeordnet, wobei weiter bevorzugt das betreffende Kühlloch sich zumindest teilweise, vorzugsweise vollständig durch die besagte Dichtspitze erstreckt.According to a particularly preferred embodiment, at least one sealing tip is arranged on the outwardly facing surface of the tip wall, with the one in question being further preferred Cooling hole extends at least partially, preferably completely, through said sealing tip.

Mit dieser Ausgestaltung lassen sich Dichtspitzen bereitstellen, die trotz ihrer vergleichsweise geringen Wandstärke innenkühlbar sind. Die Wandstärken derartiger Dichtspitzen können eine Größe von ungefähr 2 mm aufweisen, wobei die Kühllöcher einen Durchmesser von 1,0 mm und kleiner aufweisen können.With this configuration, sealing tips can be provided which, despite their comparatively small wall thickness, can be internally cooled. The wall thicknesses of such sealing tips can have a size of approximately 2 mm, the cooling holes being able to have a diameter of 1.0 mm and smaller.

Insgesamt werden mit der Erfindung folgende Ziele erreicht:
Durch Aufbringen von schräg, axial und/oder radial auslaufenden Rippen auf den seitlichen Innenwänden der Schaufelblätter und durch die einfachere Positionierung der Kühllöcher zur Kühlung des Spitzenbereiches des Schaufelblatts in diesem kann erreicht werden, dass die Einströmöffnung der Kühllöcher auf der Innenseite eine sowohl radial als auch axial angestellte Ellipse bildet. Durch Fertigen des Kühllochs mittels Laserbohren oder Erodieren kann ferner der projizierte Durchmesser des Kühllochs im Einströmbereich kleiner gehalten werden als stromab davon oder im Auslaufbereich. Auf diese Weise lässt sich die Länge der kürzeren Achse der Ellipse verringern, verglichen mit dem Durchmesser eines runden Kühllochs. Durch die Anordnung einer vorwiegend in axialer Richtung erstreckenden Rippe auf der Innenseite der Schaufelwand radial mit Kühlloch kann erreicht werden, dass für vorwiegend durch die Fliehkraft getriebene, sich radial bewegende Partikel ebenso eine Sprungschanze vorhanden ist, die sie über die Einströmöffnung springen lässt, aber nicht darein.Overall, the following goals are achieved with the invention:
By applying obliquely, axially and / or radially tapering ribs on the inner side walls of the airfoil and by simpler positioning of the cooling holes for cooling the tip area of the airfoil in this, it can be achieved that the inflow opening of the cooling holes on the inside is both radial and axially formed ellipse. By producing the cooling hole by means of laser drilling or eroding, the projected diameter of the cooling hole in the inflow region can also be kept smaller than downstream of it or in the outlet region. In this way, the length of the shorter axis of the ellipse can be reduced compared to the diameter of a round cooling hole. By arranging a rib extending predominantly in the axial direction on the inside of the blade wall radially with a cooling hole, it can be achieved that a jumping hill is also available for particles which are mainly driven by centrifugal force and which can make them jump over the inflow opening, but not in it.

Es versteht sich von selbst, dass die erfindungsgemäßen Paare von Rippe und Kühlloch an beiden Seitenwänden des Schaufelblatts angewendet werden können. Ebenso selbstverständlich ist es derartige Schaufelblätter bzw. Turbinenschaufeln durch additive Verfahren, beispielsweise selektives Laserschmelzen oder dergleichen, herzustellen.It goes without saying that the pairs of rib and cooling hole according to the invention can be applied to both side walls of the airfoil. It is also a matter of course to manufacture such blades or turbine blades by means of additive processes, for example selective laser melting or the like.

Auch wenn in der Beschreibung bzw. in den Patentansprüchen einige Begriffe jeweils im Singular oder in Verbindung mit einem Zahlwort verwendet werden, so soll der Umfang der Erfindung für diese Begriffe nicht auf den Singular oder das jeweilige Zahlwort eingeschränkt sein. Ferner sind die Wörter "ein" bzw. "eine" nicht als Zahlwörter, sondern als unbestimmte Artikel zu verstehen.Even if some terms are used in the description or in the patent claims in each case in the singular or in connection with a number word, the scope of the invention for these terms should not be restricted to the singular or the respective number word. Furthermore, the words "a" or "an" are not to be understood as numerical words, but as indefinite articles.

Die oben beschriebenen Eigenschaften, Merkmale und Vorteile der Erfindung sowie die Art und Weise, wie diese erreicht werden, werden verständlich im Zusammenhang mit der folgenden Beschreibung der Ausführungsbeispiele anhand der nachfolgenden Figuren näher erläutert.The properties, features and advantages of the invention described above and the manner in which they are achieved are explained in more detail in connection with the following description of the exemplary embodiments with reference to the following figures.

Hierbei sind die Figuren lediglich schematisch dargestellt, wodurch insbesondere keine Einschränkung der Ausführbarkeit der Erfindung die Folge ist.Here, the figures are only shown schematically, which in particular results in no restriction of the feasibility of the invention.

Es zeigen:

Figur 1
eine Turbinenlaufschaufel in einer perspektivischen schematischen Darstellung,
Figur 2
den Längsschnitt durch das Schaufelblatt der Turbinenlaufschaufel gemäß Figur 1 als ein erstes Ausführungsbeispiel,
Figur 3
die Seitenansicht auf eine Innenfläche einer Seitenwand des Schaufelblatts gemäß der Ansicht III-III,
Figur 4
den Querschnitt gemäß der Schnittlinie IV-IV durch das Schaufelblatt gemäß Figur 2 und
Figur 5
ein alternatives Ausführungsbeispiel einer erfindungsgemäßen Rippe-Kühlloch-Paarung in einer Seitenansicht
Show it:
Figure 1
a turbine blade in a perspective schematic representation,
Figure 2
the longitudinal section through the blade of the turbine blade according to Figure 1 as a first embodiment,
Figure 3
the side view of an inner surface of a side wall of the airfoil according to the view III-III,
Figure 4
the cross section according to section line IV-IV through the airfoil according to Figure 2 and
Figure 5
an alternative embodiment of a rib-cooling hole pairing according to the invention in a side view

Nachfolgend sind identische technische Merkmale in allen Figuren mit gleichen Bezugszeichen versehen. Zudem können Merkmale unterschiedlicher Ausführungsbeispiele in beliebiger Weise miteinander kombiniert werden.In the following, identical technical features are provided with the same reference symbols in all figures. In addition, features of different exemplary embodiments can be combined with one another in any manner.

Figur 1 zeigt eine Turbinenschaufel 10 in einer perspektivischen Darstellung. Die Turbinenschaufel 10 ist gemäß Figur 1 als Laufschaufel ausgebildet. Sie umfasst einen tannenbaumförmigen Schaufelfuß 12 sowie eine daran angeordnete Plattform 14. Sonach schließt sich an die Plattform 14 ein Schaufelblatt 16 an, welches aerodynamisch gekrümmt ist. Ob das Schaufelblatt 16 von einer thermischen Schutzschicht überzogen ist oder nicht, ist für die Erfindung unerheblich. Das Schaufelblatt 16 umfasst eine Saugseitenwand 22 sowie eine Druckseitenwand 24. Bezogen auf ein das Schaufelblatt 16 umströmendes Heißgas erstrecken sich diese Wände von einer Vorderkante 18 zu einer Hinterkante 20. Entlang der Hinterkante 20 sind eine Vielzahl von Öffnungen 28 zur Ausblasung von Kühlmittel vorgesehen, welche durch dazwischen angeordnete Stege 30 voneinander getrennt sind. Das Schaufelblatt 16 erstreckt sich längs einer Spannweiterichtung, welche mit einer Radialrichtung einer Turbine zusammenfällt, von einem fußseitigen Ende 26 zu einem kopfseitigen Ende 27. Letzteres ist auch als Schaufelspitze bekannt. Bei einer Verwendung der gezeigten Turbinenschaufel 10 in einer axial durchströmten Gasturbine deckt sich die Spannweiterichtung mit der Radialrichtung R der Gasturbine. Figure 1 shows a turbine blade 10 in a perspective view. The turbine blade 10 is in accordance with Figure 1 designed as a moving blade. It comprises a fir-tree-shaped blade root 12 and a platform 14 arranged thereon. A blade 16, which is aerodynamically curved, then adjoins the platform 14. Whether the airfoil 16 is covered by a thermal protective layer or not is irrelevant to the invention. The airfoil 16 comprises a suction side wall 22 and a pressure side wall 24. Relative to a hot gas flowing around the airfoil 16, these walls extend from a front edge 18 to a rear edge 20. Along the rear edge 20, a plurality of openings 28 for blowing out coolant are provided, which are separated from one another by webs 30 arranged therebetween. The airfoil 16 extends along a span direction, which coincides with a radial direction of a turbine, from a foot-side end 26 to a head-side end 27. The latter is also known as the blade tip. When the turbine blade 10 shown is used in a gas turbine with axial flow, the span direction coincides with the radial direction R of the gas turbine.

Figur 2 zeigt eine Schnittdarstellung durch das Schaufelblatt 16 gemäß der Schnittlinie II - II als erstes Ausführungsbeispiel eines erfindungsgemäßen Schaufelblatts 16. In der Figur 2 ist lediglich das in Bezug auf die Spannweite bzw. Radialrichtung R der Gasturbine radial äußere Ende des Schaufelblatts 16, also die Schaufelblattspitze dargestellt. Eingebaut in einer Gasturbine erstreckt sich das Schaufelblatt 1 in die Radialrichtung R. Weitere Achsen der Gasturbine sind mit A und U bezeichnet, wobei A für Axialrichtung steht und U die Umfangsrichtung repräsentiert. Diese werden nachfolgend bei Bedarf verwendet, um die Anordnung einfacher zu beschreiben. Figure 2 shows a sectional view through the airfoil 16 according to the section line II - II as the first embodiment of an airfoil 16 according to the invention Figure 2 only the radially outer end of the airfoil 16 with respect to the span or radial direction R of the gas turbine, ie the airfoil tip, is shown. Installed in a gas turbine, the airfoil 1 extends in the radial direction R. Further axes of the gas turbine are denoted by A and U, where A stands for the axial direction and U represents the circumferential direction. These are used below, if necessary, to describe the arrangement more easily.

Das Schaufelblatt 16 weist an dem kopfseitigen Ende 27 eine Spitzenwand 34 auf, welche einen Hohlraum 32 nach außen hin begrenzt. Die Spitzenwand 34 steht im Wesentlichen in einem rechten Winkel zur saugseitigen Seitenwand 22 und geht in diese über. Im Übergangsbereich ist an einer zum Hohlraum 32 weisenden Innenfläche 40 der saugseitigen Seitenwand 22 eine Rippe 38 angeordnet. Die Rippe 38 erstreckt sich geradlinig von ihrem kopfseitig angeordneten Ende 46 zu ihrem fußseitig angeordneten Ende 44.The airfoil 16 has a tip wall 34 at the head-side end 27, which delimits a cavity 32 towards the outside. The tip wall 34 is essentially at a right angle to the suction side wall 22 and merges into it. In the transition region, a rib 38 is arranged on an inner surface 40 of the suction side wall 22 facing the cavity 32. The rib 38 extends in a straight line from its end 46 arranged on the head side to its end 44 arranged on the foot side.

Radial nach innen benachbart ist unter Abstand zur Rippe 38 eine in Axialrichtung verlaufende weitere Rippe 39 vorgesehen, um bei ggf. radial auftretender Kühlströmung Partikel abzulenken.A further rib 39 extending in the axial direction is provided radially inward at a distance from the rib 38 in order to deflect particles in the event of a radially occurring cooling flow.

An der radial nach außen weisenden Fläche 52 der Spitzenwand 34 ist zudem eine Dichtspitze 48 angeordnet und Teil dieser. Derartige Dichtspitzen, im Englischen auch als "squealer tips" bekannt, werden meist als radiale Verlängerungen der Seitenwände 22, 24 der Turbinenlaufschaufel 10 wahrgenommen. Sie dienen zur Reduzierung eines Spalts zwischen der Schaufelspitze und der diesen gegenüberliegenden Heißgaspfadbegrenzung der Gasturbine. Die Dichtspitzen 48 können in Bezug auf die äußeren Seitenflächen der saugseitigen Seitenwand 22 bzw. druckseitigen Seitenwand 24, wie gezeigt, stufenlos angeordnet sein.A sealing tip 48 is also arranged on the radially outward-facing surface 52 of the tip wall 34 and is part of this. Such sealing tips, also known as "squealer tips" in English, are usually perceived as radial extensions of the side walls 22, 24 of the turbine blade 10. They serve to reduce a gap between the blade tip and the hot gas path limitation of the gas turbine opposite this. The sealing tips 48 can be arranged in a stepless manner with respect to the outer side surfaces of the suction side wall 22 or pressure side wall 24, as shown.

Gemäß dem in Figur 2 dargestellten Ausführungsbeispiel erstreckt sich ein Kühlloch 36 durch die Spitzenwand 34 samt Dichtspitze 48 bis in die Rippe 38. Das Kühlloch 36 weist eine Einströmöffnung 42 für ein Kühlfluid auf. Ein dem Hohlraum 32 zuführbares Kühlfluid kann in besagte Öffnung 42 einströmen, entlang des Kühllochs 36 strömen und an dem äußeren Ende austreten. Währenddessen kühlt das Kühlfluid den lokalen Bereich der saugseitigen Seitenwand 22, der Spitzenwand 34 und insbesondere die Dichtspitze 48. Es ist selbstverständlich, dass an der Schaufelspitze einer Turbinenschaufel 10 mehrere der gezeigten und nachfolgend weiter detailliert beschriebene Paare von Kühllöchern 36 und Rippen 38 vorgesehen sein können. Das gilt insbesondere dann, wenn die Dichtspitze 48 sich entlang des gesamten Umlaufs des Schaufelblatts 16 erstreckt.According to the in Figure 2 In the exemplary embodiment shown, a cooling hole 36 extends through the tip wall 34 together with the sealing tip 48 into the rib 38. The cooling hole 36 has an inflow opening 42 for a cooling fluid. A cooling fluid that can be supplied to the cavity 32 can flow into said opening 42, flow along the cooling hole 36 and exit at the outer end. In the meantime, the cooling fluid cools the local area of the suction side wall 22, the tip wall 34 and in particular the sealing tip 48. It goes without saying that at the blade tip of a turbine blade 10 several of the shown and described in more detail below Pairs of cooling holes 36 and fins 38 may be provided. This applies in particular if the sealing tip 48 extends along the entire circumference of the airfoil 16.

Das Kühlloch 36 muss sich nicht zwingend durch die Dichtspitze 48 erstrecken. Gemäß einer alternativen Ausgestaltung kann das Kühlloch 36 auch seitlich der Dichtspitze 48 enden. Es kann beispielsweise heißgasseitig enden oder auch im dem Spitzenfreiraum 39.The cooling hole 36 does not necessarily have to extend through the sealing tip 48. According to an alternative embodiment, the cooling hole 36 can also end at the side of the sealing tip 48. For example, it can end on the hot gas side or also in the tip free space 39.

Figur 3 zeigt die Draufsicht auf das Innere der Schaufelspitze gemäß der Schnittlinie III-III aus Figur 2. Aufgrund der Bezugnahme der unterschiedlichen Richtungen bei verbautem Schaufelblatt 16 in einer Gasturbine ist erkennbar, dass die Rippe 38 gegenüber der Radialrichtung geneigt ausgestaltet ist. Die Rippe 38 gemäß dem hier gezeigten Ausführungsbeispiel erstreckt sich in geradliniger Art und Weise von ihrem kopfseitigen Ende 46 zu ihrem fußseitigen Ende 44. Gleichzeitig ist das sich durch die Dichtspitze 48, die Spitzenwand 34 bis in die Rippe 38 hinein erstreckende Kühlloch 36 parallel zur Radialrichtung R ausgerichtet, dabei jedoch in Umfangsrichtung geneigt (Fig. 2). Die skizzierten Ausrichtungen des Kühllochs 36 und der Rippe 37 sind nicht zwingend erforderlich, sondern vielmehr jeweils abhängig von der Orientierung des aerodynamisch gekrümmten Schaufelblatts im Raum einerseits und dem Ort des Kühllochs andererseits. Bevorzugt ist eine Kanalachse 37 des Kühllochs 36 im Bereich der Einströmöffnung 42 gegenüber der Längserstreckung der Rippe 38 stumpfwinklig geneigt. Um dies zu erreichen, kann beispielsweise das Kühlloch 36 ebenso wie die Rippe 38 in Umfangsrichtung U und/oder in Axialrichtung A geneigt sein. Ein in Axialrichtung geneigtes Kühlloch 36 ist als zweites Ausführungsbeispiel in Figur 5 dargestellt und mündet in der in Radialrichtung gekrümmt ausgestalteten Rippe 38. Weiterhin zeigt Figur 5 neben den bereits beschriebenen Merkmalen eine elliptische Einströmöffnung 42, deren kürzere Achse 54 kleiner ist als der Durchmesser des restlichen, im Querschnitt kreisrunden Kühllochs 36. Figure 3 shows the top view of the interior of the blade tip according to the section line III-III Figure 2 . Based on the reference to the different directions when the airfoil 16 is installed in a gas turbine, it can be seen that the rib 38 is designed to be inclined with respect to the radial direction. The rib 38 according to the exemplary embodiment shown here extends in a straight line from its head-side end 46 to its foot-side end 44. At the same time, the cooling hole 36 extending through the sealing tip 48, the tip wall 34 into the rib 38 is parallel to the radial direction R aligned, but inclined in the circumferential direction ( Fig. 2 ). The outlined orientations of the cooling hole 36 and the rib 37 are not absolutely necessary, but rather in each case depending on the orientation of the aerodynamically curved airfoil in the space on the one hand and the location of the cooling hole on the other hand. A channel axis 37 of the cooling hole 36 is preferably inclined at an obtuse angle in the region of the inflow opening 42 with respect to the longitudinal extent of the rib 38. To achieve this, the cooling hole 36, for example, as well as the rib 38, can be inclined in the circumferential direction U and / or in the axial direction A. A cooling hole 36 inclined in the axial direction is shown in FIG Figure 5 shown and opens into the rib 38, which is curved in the radial direction Figure 5 In addition to the features already described, an elliptical inflow opening 42, the shorter axis 54 of which is smaller than the diameter of the remaining cooling hole 36, which is circular in cross section.

Figur 4 zeigt den Schnitt durch das schaufelspitzenseitige Ende 27 des Schaufelblatts 16 gemäß der Schnittlinie IV-IV aus Figur 2. Gemäß dem gezeigten Ausführungsbeispiel sind saugseitig zwei erfindungsgemäße Rippen 38 vorgesehen, von denen die erste asymmetrisch gewölbt von der Innenfläche 40 der saugseitigen Seitenwand 22 hervorsteht. Die zweite der beiden erfindungsgemäßen Rippen 38 ist dagegen in dieser Querschnittsbetrachtung, welche Querschnittsebene normal zur Radialrichtung R liegt, in ihrer Form dreieckig. Es ist nicht erforderlich, dass die Rippe ähnlich wie Turbulatoren von der Innenfläche hervorspringen, der Übergang von Innenfläche 40 zur Seitenfläche der Rippe 38 kann insbesondere auf ihrer Anströmseite auch stufenlos und somit aerodynamisch verlustarm ausgestaltet sein. Figure 4 shows the section through the blade tip-side end 27 of the blade 16 according to the section line IV-IV Figure 2 . According to the exemplary embodiment shown, two ribs 38 according to the invention are provided on the suction side, of which the first asymmetrically curved protrudes from the inner surface 40 of the suction side wall 22. In contrast, in this cross-sectional view, which cross-sectional plane lies normal to the radial direction R, the second of the two ribs 38 according to the invention is triangular in shape. It is not necessary for the rib to protrude from the inner surface like turbulators, the transition from the inner surface 40 to the side surface of the rib 38 can also be designed in a stepless manner and thus with low aerodynamic losses, particularly on its upstream side.

Die Kühllöcher 36 münden in einer der Seitenflächen der Rippen 38. Die Lage der Öffnung 42 ist erfindungsgemäß in derjenigen Seitenfläche der Rippe 38, welche abseits einer maximalen Rippenhöhe H angeordnet ist. Die Rippenhöhe H wird bezogen auf die restliche Innenfläche 40 der saugseitigen Wand 22.The cooling holes 36 open into one of the side surfaces of the ribs 38. According to the invention, the position of the opening 42 is in that side surface of the rib 38 which is arranged away from a maximum rib height H. The rib height H is based on the remaining inner surface 40 of the suction-side wall 22.

Im Betrieb wird im Inneren des Schaufelblatts 16 der innengekühlten Turbinenlaufschaufel 10 ein Kühlfluid, vorzugsweise Kühlluft, zugeführt. Der Hohlraum 32 wird demzufolge von dem Kühlfluid durchströmt und das Kühlfluid weist eine aufgrund der Topologie des Hohlraums 32 und der Position einer Kühlluftzuführung und der Position angrenzender Abströmkanäle eine vorgegebene Hauptströmungsrichtung 50 auf. Diese Hauptströmungsrichtung ist in unmittelbarer Nähe der erfindungsgemäßen Rippe 38 zu ermitteln. Da das Kühlfluid nie gänzlich frei von Schmutzpartikeln sein kann, ist es von Vorteil, wenn die Einströmöffnung 42 des Kühllochs 36 auf derjenigen Seite der betreffenden Rippe 38 angeordnet ist, welche dem auf die betreffende Rippe zuströmenden Kühlfluid abgewandt ist. Die Einströmöffnung 42 des Kühllochs 36 liegt sozusagen eher im Windschatten - im Lee - der maximalen Rippenhöhe H. Vom Kühlfluid mitgeführte Partikel werden aufgrund der Form der Rippe 38 in eine Strömungsbahn gelenkt, in der sie sich mit zunehmend zurückgelegten Weg immer weiter von den Innenflächen der Seitenwände 22, 24 entfernen bis zum Ort der maximalen Rippenhöhe H. Anschließend strömen sie aufgrund ihrer Trägheit und der von der Einströmöffnung 42 weg weisenden Strömungsrichtung daran vorbei; sie können nur unter erschwerten Bedingungen in das Kühlloch 36 einströmen. Dies hat zur Folge, dass partikelärmere Luft - im Vergleich zum Stand der Technik - in die Kühllöcher 36 einströmt und damit die Gefahr einer Verstopfung reduziert ist. Dies ermöglicht die Verwendung von Kühllöchern 36 mit besonders kleinem Durchmesser, beispielsweise auch kleiner als ein Millimeter bei verringerter Gefahr einer Verstopfung der Einströmöffnungen 42 bzw. der Kühllöcher 36 durch mitgeführte Partikel.In operation, a cooling fluid, preferably cooling air, is supplied to the internally cooled turbine blade 10 in the interior of the airfoil 16. The cooling fluid consequently flows through the cavity 32 and the cooling fluid has a predetermined main flow direction 50 due to the topology of the cavity 32 and the position of a cooling air supply and the position of adjacent outflow channels. This main flow direction is to be determined in the immediate vicinity of the rib 38 according to the invention. Since the cooling fluid can never be completely free of dirt particles, it is advantageous if the inflow opening 42 of the cooling hole 36 is arranged on that side of the rib 38 in question which faces away from the cooling fluid flowing into the rib in question. The inflow opening 42 of the cooling hole 36 is more or less in the slipstream - in the lee - of the maximum fin height H. From the cooling fluid entrained particles are directed into a flow path due to the shape of the rib 38, in which they move away with increasing distance from the inner surfaces of the side walls 22, 24 to the location of the maximum rib height H. Then they flow due to their inertia and that of the flow direction facing away from the inflow opening 42; they can only flow into the cooling hole 36 under difficult conditions. As a result, air with less particles - compared to the prior art - flows into the cooling holes 36 and thus the risk of clogging is reduced. This enables the use of cooling holes 36 with a particularly small diameter, for example also smaller than one millimeter, with a reduced risk of the inflow openings 42 or the cooling holes 36 being blocked by entrained particles.

Aufgrund der gewölbten Kontur der Rippe 38 und der gegenüber der Radialrichtung R entweder in Umfangsrichtung U und/oder in Axialrichtung A angestellten Ausrichtungen der prinzipiell geradlinigen Kühllöcher 36 ist die Einströmöffnung 42 der in der Rippe 38 mündenden Kühllöcher 36 nicht kreisrund, sondern elliptisch geneigt mit einer längeren Achse und einer kürzeren Achse. Selbst dadurch wäre es bei zum geradlinigen Kühlloch 36 fluchtend strömender Kühlluft Partikel erschwert, in das betreffende Kühlloch 36 einzuströmen.Due to the curved contour of the rib 38 and the orientations of the basically straight cooling holes 36, which are made in the circumferential direction U and / or in the axial direction A with respect to the radial direction R, the inflow opening 42 of the cooling holes 36 opening into the rib 38 is not circular, but rather is elliptically inclined with one longer axis and a shorter axis. Even this would make it difficult for particles flowing in cooling air to flow in a straight line toward cooling hole 36 to flow into cooling hole 36 in question.

Das Kühlloch 36 kann nach dem Gießen der Turbinenschaufel 10 nachträglich durch Bohren hergestellt werden. Von besonderem Vorteil ist die gegenüber der Radialrichtung R geneigte Orientierung der Rippe 38. Beispielsweise bei einem geradlinigen, in Radialrichtung R gebohrten Kühlloch 36 bietet die geneigte Rippe 38 (Fig. 3) den Vorteil, dass das Kühlloch 36 in einem vergleichsweise großen axialen Abschnitt AB angesiedelt sein kann. Solange das Kühlloch 36 in diesem Abschnitt AB angesiedelt ist, weist es eine elliptisch geformte Einströmöffnung 42 auf, die stets auf der stromab des ankommenden Kühlfluids liegenden Seite im Lee angeordnet ist. Dies verbessert die Herstellbarkeit einer solchen Turbinenschaufel 10, da der Abschnitt AB, in dem das Kühlloch zu bohren ist, vergleichsweise groß und damit einfacher zu treffen ist.After casting the turbine blade 10, the cooling hole 36 can be subsequently produced by drilling. The orientation of the rib 38 which is inclined with respect to the radial direction R is particularly advantageous. For example, in the case of a rectilinear cooling hole 36 drilled in the radial direction R, the inclined rib 38 offers ( Fig. 3 ) the advantage that the cooling hole 36 can be located in a comparatively large axial section AB. As long as the cooling hole 36 is located in this section AB, it has an elliptically shaped inflow opening 42, which is always arranged on the side lying downstream of the incoming cooling fluid in the lee. This improves the manufacturability of such a turbine blade 10, since the section AB in which the cooling hole is to be drilled is comparatively large and therefore easier to hit.

Insgesamt wird mit der Erfindung ein Schaufelblatt 16 für eine innengekühlte Turbinenlaufschaufel 10 bereitgestellt, umfassend eine saugseitige Seitenwand 22 und eine druckseitige Seitenwand 24, die sich von einer gemeinsamen Vorderkante 18 zu einer gemeinsamen Hinterkante 20 und in einer Spannweiterichtung von einem fußseitigen Ende 26 zu einem kopfseitigen Ende 27 erstreckend einen Hohlraum zumindest teilweise umschließen, wobei das kopfseitige Ende 27 eine den Hohlraum 32 kopfseitig begrenzende Spitzenwand 34 umfasst, in welcher zumindest ein Kühlloch 36, vorzugsweise mehre Kühllöcher 36 zum Ausleiten von im Inneren strömbaren Kühlfluid vorgesehen ist bzw. sind. Um eine Turbinenschaufel bereitzustellen, bei der die Gefahr von Verstopfungen von Kühllöchern verringert ist und somit die Standzeit der Turbinenschaufel 10 verlängert sein kann, wird vorgeschlagen, dass im Hohlraum 32 zumindest eine sich von der Spitzenwand 34 aus in Richtung des fußseitigen Endes 42 erstreckende Rippe vorzugsweise mehrere derartige Rippen 38, von der diese Rippe umgebenden Innenflächen 40 der saugseitigen Seitenwand 22 und/oder der Innenfläche 40 der druckseitigen Seitenwand 24 hervorsteht und dass eine - bezogen auf das Kühlfluid - Einströmöffnung 42 des zumindest einen Kühllochs 36 in der betreffenden Rippe 38 seitlich mündet. Overall, the invention provides an airfoil 16 for an internally cooled turbine blade 10, comprising a suction-side wall 22 and a pressure-side wall 24, which extend from a common front edge 18 to a common rear edge 20 and in a span direction from a foot-side end 26 to a head-side End 27 extends at least partially enclosing a cavity, the head-side end 27 comprising a tip wall 34 delimiting the cavity 32 on the head side, in which at least one cooling hole 36, preferably a plurality of cooling holes 36 is provided for discharging cooling fluid that can flow inside. In order to provide a turbine blade in which the risk of clogging of cooling holes is reduced and the service life of the turbine blade 10 can be extended, it is proposed that in the cavity 32 preferably at least one rib extending from the tip wall 34 towards the foot-side end 42 is preferred a plurality of such ribs 38, from which this rib surrounding inner surfaces 40 of the suction side wall 22 and / or the inner surface 40 of the pressure side wall 24 protrudes and that - in relation to the cooling fluid - inflow opening 42 of the at least one cooling hole 36 opens laterally into the relevant rib 38 .

Claims (11)

  1. Blade airfoil (16) for an internally cooled turbine rotor blade (10),
    comprising a suction-side side wall (22) and a pressure-side side wall (24), which, extending from a leading edge (18) to a trailing edge (20) and in a span direction from a root-side end (26) to a tip-side end (27), at least partially enclose a cavity (32),
    wherein the tip-side end (27) comprises a tip wall (34) which delimits the cavity (32) at the tip side and in which at least one cooling hole (36), preferably multiple cooling holes (36), for the discharge of cooling fluid that can be caused to flow in the interior is or are provided,
    characterized
    in that, in the cavity (32), at least one rib (38) which extends from the tip wall (34) in the direction of the root-side end, preferably multiple such ribs (38), project(s) from the inner surface (40) of the suction-side side wall (22) or from the inner surface (40) of the pressure-side side wall (24), and
    in that an inflow opening (42) of the at least one cooling hole (36) opens out laterally in the respective rib (38).
  2. Blade airfoil (16) according to Claim 1,
    in which the cooling hole (36) has a channel axis (37) which, at least in the region of the inflow opening (42) of the cooling hole (36), is inclined relative to the longitudinal extent of the rib (38).
  3. Blade airfoil (16) according to Claim 1 or 2,
    in which the inflow opening (42) has an elliptical shape with a relatively short axis and with a relatively long axis, wherein the relatively short axis is shorter than the diameter of the rest of the cooling hole (36).
  4. Blade airfoil (16) according to Claim 1, 2 or 3,
    in which the respective rib (38) has, in a cross-sectional plane normal with respect to the span direction, a curved contour with a maximum rib height (H) in relation to the rest of the inner surface, and the inflow-side end (42) of the respective cooling hole (36) is arranged laterally with respect to the location of the maximum rib height.
  5. Blade airfoil (16) according to Claim 1, 2 or 3,
    in which the respective rib (38) has, in a cross-sectional plane normal with respect to the span direction, a polygonal contour with a maximum rib height (H) in relation to the rest of the inner surface, and the inflow opening of the respective cooling hole is arranged on a laterally arranged surface of the rib.
  6. Blade airfoil (16) according to at least one of the preceding claims,
    in which the respective rib (38) is, from its tip-side end (46) to its end (44) arranged at the root side, inclined in the direction of the leading edge or in the direction of the trailing edge.
  7. Blade airfoil (16) according to at least one of the preceding claims,
    in which the cavity (32) adjacent to the respective rib (38) is such that the major supply of coolant to said cavity is arranged on that side of the respective rib which is averted from that surface of the rib which has the inflow opening of the cooling hole.
  8. Blade airfoil (16) according to at least one of the preceding claims,
    in which the tip wall (34) comprises at least one sealing tip (48) on its outwardly pointing surface.
  9. Blade airfoil (16) according to at least Claim 8, in which the respective cooling hole (36) extends through at least part, preferably the entirety, of the sealing tip (48).
  10. Turbine rotor blade (10) having a blade airfoil (16), the blade airfoil (16) of which corresponds to a blade airfoil of Claims 1 to 9.
  11. Method for producing a blade airfoil (16) according to one of Claims 1 to 9,
    - providing a blade airfoil (16) produced preferably by precision casting, comprising a suction-side side wall (22) and a pressure-side side wall (24), which, extending along a profile centerline from a common leading edge to a common trailing edge and in a span direction from a root-side end to a tip-side end, at least partially enclose a cavity,
    wherein the tip-side end comprises a tip wall which delimits the cavity at the tip side,
    wherein, in the cavity of the blade airfoil, at least one rib which extends from the tip wall in the direction of the root-side end, preferably multiple such ribs, project(s) from the inner surface of the suction-side side wall or from the inner surface of the pressure-side side wall, and
    - boring the at least one cooling hole such that its inflow opening opens out in one of the respective ribs.
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Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10551327B2 (en) * 2018-04-11 2020-02-04 General Electric Company Cooling hole inspection system
US11274559B2 (en) * 2020-01-15 2022-03-15 Raytheon Technologies Corporation Turbine blade tip dirt removal feature
GB2591298B (en) * 2020-01-27 2022-06-08 Gkn Aerospace Sweden Ab Outlet guide vane cooler
KR102466386B1 (en) * 2020-09-25 2022-11-10 두산에너빌리티 주식회사 Turbine blade, turbine including the same

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4142824A (en) * 1977-09-02 1979-03-06 General Electric Company Tip cooling for turbine blades
JPH0663442B2 (en) * 1989-09-04 1994-08-22 株式会社日立製作所 Turbine blades
GB2343486B (en) 1998-06-19 2000-09-20 Rolls Royce Plc Improvemnts in or relating to cooling systems for gas turbine engine airfoil
US6224336B1 (en) * 1999-06-09 2001-05-01 General Electric Company Triple tip-rib airfoil
AU2003205491A1 (en) * 2002-03-25 2003-10-08 Alstom Technology Ltd Cooled turbine blade
GB0524735D0 (en) 2005-12-03 2006-01-11 Rolls Royce Plc Turbine blade
US7287959B2 (en) * 2005-12-05 2007-10-30 General Electric Company Blunt tip turbine blade
US8734107B2 (en) * 2011-05-31 2014-05-27 General Electric Company Ceramic-based tip cap for a turbine bucket
GB201120273D0 (en) * 2011-11-24 2012-01-04 Rolls Royce Plc Aerofoil cooling arrangement
US10227876B2 (en) * 2015-12-07 2019-03-12 General Electric Company Fillet optimization for turbine airfoil

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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EP3473808A1 (en) 2019-04-24
US20190120066A1 (en) 2019-04-25
US10746027B2 (en) 2020-08-18

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