EP3246521B1 - Discharge area for guide blade cover and base panels - Google Patents

Description

The invention relates to a stator segment for a turbomachine, a rotor blade for a turbomachine and an assembly for a turbomachine.

Turbomachines (such as aeroengines and stationary gas turbines) include a rotor having a plurality of blades and at least one axially adjacent row of blades. The vanes serve to optimize the flow conditions for the blades; In the main flow direction vanes and blades are arranged one behind the other. The term "vane" or "vane segment" is to be understood in the context of the present invention wide, especially in the sense of "stator". Thus, this term also encompasses flow-deflecting profiles disposed axially behind the last row of blades of a low-pressure turbine as part of a so-called turbine outlet housing, and flow-deflecting profiles arranged as components of a turbine intermediate housing between two turbine regions, such as low-pressure turbine and high-pressure turbine.

A vane row may include a radially inner and a radially outer shroud as well as a plurality of vane blades disposed therebetween; The terms "radial" or "radial", "axial" or "axial" and "circumferential" refer in this document - unless otherwise stated - always on the axis of rotation of a (existing or intended) rotor shaft which is surrounded by the vane row. As a rule, the axis of rotation corresponds to the so-called machine axis of the turbomachine. The vane row may be composed of a plurality of vane segments, each of which may include a radially inner and / or a radially outer cover plate and a vane blade or a plurality of vane blades. The radially inner cover plates together form the inner shroud and the radially outer cover plates form the outer shroud; the shrouds are preferably each formed as a closed ring which forms a radial boundary for the main gas flow.

In a radially inner region, the rotor blades can analogously have a base plate which is set up, for example via a rotor disk plugged or inserted blade root to be attached to a rotor shaft or to be. Preferably, such a base plate has a projection in the axial direction, which is adapted to reduce a radial leakage flow together with a projection of the shroud of a row of guide vanes.

Turbomachinery with such guide and blade arrangements have been continually improved over time. For example, in the publications DE 10 2008 011 746 A1 . US 2007/0243061 A1 and EP 2 236 748 A1 ways are disclosed to reduce adverse leakage currents. Another example is from the US 2014/0205443 A1 known.

In addition to the goal of optimizing the function of the turbomachine, however, the possibility of a damage case is also to be considered. In particular, it has been shown that a fraction of the rotor shaft has major disadvantages. The present invention therefore has the object to provide a technique with which the negative effects of such a rotor shaft break are reduced.

The object is achieved by a vane segment according to claim 1, an assembly for a turbomachine according to claim 3 and a turbomachine according to claim 7. Advantageous embodiments are disclosed in the subclaims, the description and the figures.

An inventive vane segment for a turbomachine has at least one vane with a radially inner cover plate; The attribute "radially inner" refers to an intended or already realized arrangement of the vane segment in a turbomachine (or on its axis of rotation). The cover plate has a cover plate surface configured to be disposed in the turbomachine facing a blade row upstream of the nozzle segment. In this case, the cover plate surface extends substantially along a (imaginary) conical surface, whose cone axis coincides with the axis of rotation of a rotor shaft.

In particular, the vane segment is thus adapted to be assembled with one or more further vane segments and thereby form an annular vane row whose central axis coincides with the axis of rotation of the rotor shaft. According to the invention, the cover plate surface faces an upstream row of blades in the axial direction and runs along the conical surface (which is preferably the lateral surface of a straight circular cone), ie it is conical to the axis of rotation. After a proper assembly of the vane segment, the cover plate surface is preferably - viewed in a direction provided for the main flow direction - arranged on the front side of the cover plate.

According to an advantageous embodiment, an inventive vane segment also has a radially outer cover plate; Analogously to the above, the attribute "radially outer" here refers to an intended or already realized arrangement of the vane segment in a turbomachine (and its axis of rotation). At least one vane blade is preferably arranged between the radially inner and a radially outer cover plate.

A blade for a turbomachine according to the invention has a base plate in a radially inner region (e.g., one-third, one-fourth or one-fifth of a blade extension in the radial direction facing the rotor shaft); this base plate has a base plate surface, which is adapted to be arranged in the turbomachine a shroud facing one of the blade adjacent vane row and thereby to extend substantially along a (imaginary) conical surface; whose cone axis coincides with the axis of rotation of a rotor shaft. After a proper assembly of the blade, the base plate surface is preferably - viewed in an intended main flow direction - arranged on the back of the base plate.

In particular, the base plate surface in the axial direction of a row of guide blades (obliquely) facing and extends along the conical surface (which is preferably the lateral surface of a straight circular cone), that is formed conically to the axis of rotation.

An assembly according to the invention for a turbomachine and a turbomachine according to the invention each have an inventive vane segment according to one of the embodiments disclosed in this document and a blade for a turbomachine according to the invention according to one of the embodiments disclosed in this document, wherein the blade is preferably arranged axially in front of the vane segment ,

With the respective cover plate or base plate surface running conically with respect to the axis of rotation, a guide blade segment according to the invention and a rotor blade according to the invention each have a ramp surface which can cause the rotor to brake when the rotor shaft breaks. Particularly advantageous for this purpose are the use of a combination of a guide vane segment according to the invention and a rotor blade according to the invention, in which the cover plate surface and the base plate surface can run against each other at a rotor shaft break (in which they are arranged, for example, substantially the same radial distance from the rotor shaft); It is particularly advantageous if the respective conical surface areas have substantially the same opening angle. In this case, high frictional forces can be generated in a rotor shaft break and resulting emergence of the base plate surface on the adjacent cover plate surface, which cause a corresponding deceleration.

According to an advantageous embodiment of an assembly according to the invention or a turbomachine according to the invention, the conical surface areas along which the (mentioned) cover plate surface of the guide blade segment and the (mentioned) base plate surface of the blade run have substantially the same opening angles.

Preferably, the cover plate surface and the base plate surface are arranged in a turbomachine according to the invention substantially at the same radial distance from the rotor shaft.

According to an advantageous embodiment, the cover plate surface of a guide blade segment according to the invention is aligned radially inwardly, that is to say arranged to be (obliquely) facing in a turbomachine of the rotor shaft. The cover plate surface thus abuts against an outer surface of a cone with said conical surface.

In contrast, the base plate surface of a blade according to the invention is advantageously directed radially outward, so arranged to be arranged facing away in a turbomachine rotor shaft. The base plate surface thus abuts against an inner surface of a cone with said conical surface.

In the event of rotor shaft breakage and consequent surfacing of the topplate surface onto the baseplate surface, such aligned topplate surface or surface causes the vane segment to be urged radially outward (eg, against a vane ring shell) and the vane radially inwardly against the rotor shaft. This causes a particularly effective braking of the rotor.

According to an advantageous embodiment of a guide vane segment according to the invention, the conical surface along which the cover plate surface extends is angled with respect to the axis of rotation of the rotor shaft by at most 80 °, more preferably at most 60 °, even more preferably at most 50 °. The associated cone thus has an opening angle of at most 160 °, 120 ° or 100 °.

Similarly, the conical surface along which the base plate surface of a blade of a turbomachine according to the invention extends, preferably angled relative to the axis of the rotor shaft by at most 80 °, more preferably at most 60 °, more preferably at most 50 °; the associated cone thus has an opening angle of at most 160 °, 120 ° or 100 °.

With such angles, in a rotor shaft break and a running of the cover plate on a base plate of an adjacent blade a particularly effective Braking while avoiding further damage due to a clash of vane segment and blade can be achieved.

The guide vanes and rotor blades of the turbomachine according to the invention are preferably configured in such a way that in the event of a shaft break and a concomitant translatory displacement of the blade row in the axial direction to the rear, i. in the flow direction, first the cover plate surface of the radially inner cover plate of the vane segment comes into contact with the base plate surface of the base plate of the moving blade. In this way, in the case of a shaft break, the rotational energy of the broken off part of the rotor in a predetermined component section of the turbomachine can be reduced, i. be converted into frictional heat. The surface used for this purpose is formed relatively large compared to the prior art due to the inclination of the cover plate surface and / or base plate surface to the axis of rotation. Advantageously, a part of the force with which the broken off part of the rotor is pressed axially backwards by the flow acting on the rotor blades, is deflected in the radial direction on emergence onto the cover plate surfaces of the guide blade segments due to the previously described inclination of the contact surfaces , As a result, the guide vanes can be designed more easily, without the risk that they also break off in a wave breakage.

In the following preferred embodiments of the invention will be explained in more detail with reference to drawings. It is understood that individual elements and components can be combined differently than shown. Reference numerals for corresponding elements are used across figures and may not be rewritten for each figure.

Figur 1:

ein exemplarisches erfindungsgemäßes Leitschaufelsegment in perspektivischer Darstellung;

Figur 2:

eine Anordnung eines exemplarischen erfindungsgemäßen Leitschaufelsegments und einer exemplarischen erfindungsgemäßen Laufschaufel in einer Schnittdarstellung;

Figur 3:

Teile der Anordnung gemäß Figur 2 mit imaginären Kegelflächen zur Erläuterung.

They show schematically:

FIG. 1:

an exemplary inventive Leitschaufelsegment in perspective view;

FIG. 2:

an arrangement of an exemplary guide vane segment according to the invention and an exemplary blade according to the invention in a sectional view;

FIG. 3:

Parts of the arrangement according to FIG. 2 with imaginary conical surfaces for explanation.

In the FIG. 1 For example, a vane segment 10 according to one embodiment of the present invention is illustrated. The vane segment 10 comprises an outer cover plate 12 and an inner cover plate 13, which respectively describe segments of nested cover bands with the same central axis; Between the outer cover plate 12 and the inner cover plate 13, a plurality of blades 11 is arranged. The vane segment 10 is configured to form, together with further (not shown), analogously designed stator blade segments, a row of guide vanes which runs as a ring around a rotary shaft or machine axis of the turbomachine. Its axis of rotation is substantially coincident with a central axis of the vane row, and with respect to it, the blades 11 extend substantially radially.

The radially inner cover plate 13 has, on its side facing the central axis, a fastening element 15 for fastening at least one seal, which may in particular comprise at least one sealing ring.

At her in the presentation of FIG. 1 front axial side, the cover plate 13 has a cover plate surface 14, which is adapted to be arranged in the turbomachine facing the blade segment 10 axially adjacent blade. The shroud surface 14 is tapered conically, thus extends substantially along an (imaginary) conical surface around the central axis (not shown) (and thus about the axis of rotation of the rotor shaft); this will be determined by the Figures 2 and 3 clarified.

In the FIG. 2 FIG. 3 schematically shows an arrangement of an exemplary guide vane segment 10 according to the invention and an exemplary rotor blade 20 according to the invention in a sectional representation; FIG. This arrangement can, for example, in a turbomachine according to the invention, in particular in a turbine region of the same.

The blade 20 is connected to a rotor shaft 30 and adapted to rotate with the rotor shaft about its axis of rotation A. This axis of rotation is also a central axis of the arrangement shown, with respect to which the blade 10 and the blades 11 of the blade segment are substantially radially aligned. The direction R of a planned main flow runs in the illustration of FIG. 2 left to right.

The vane segment 10 has a radially inner cover plate 13, a radially outer cover plate 12 and an airfoil 11 therebetween. On the radially inner cover plate 13, a sealing element 16 is preferably radially displaceable, in particular by means of a memory-centering suspension attached: Thus, voltages arising from thermally induced, different radial expansions between the sealing element 16 on the one hand and the Leitschaufelsegement 10 or der Leitschaufelsegementen 10 formed Leitschaufelreihe on the other hand during operation of the turbomachine, be avoided.

The rotor blade 20 has, in a radially inner region, a base plate 23, from which a rotor blade 21 extends radially outward. The base plate has on the (in the axial direction) the guide vane segment 10 side facing a projection 26, which together with the inner cover plate 13 of the vane segment reduces an adverse radial flow.

The inner cover plate 13 of the vane segment 10 has a cover plate surface 14 which faces a base plate surface 24 of the base plate 23 of the blade 20; Both surfaces are arranged substantially at the same radial distance from the rotor shaft 30. Viewed in the intended main flow direction R, the base plate surface 24 is arranged on a rear side of the base plate 23 and the cover plate surface 14 on a front side of the cover plate 13. At a fraction of the Rotor shaft can thus accumulate the base plate surface 24 on the cover plate surface 14, so that the rotor is advantageously braked.

The cover plate surface 14 and the base plate surface 24 are each arranged along (imaginary) conical surface areas; in the circular enlargement section is shown by a parallel P to the axis of rotation A, that the cover plate surface 14 and the base plate surface 24 are angled relative to the axis of rotation A by the angle α and β; Preferably, α and β are each at most 80 °, more preferably at most 60 °, even more preferably at most 50 °. It is particularly advantageous if α and β are substantially the same size; As a result, both surfaces have a particularly large contact surface in the event of their emergence on each other, resulting in a particularly large braking friction effect.

In FIG. 3 is the arrangement according to the FIG. 2 illustrated with the (imaginary) conical surfaces: As can be seen from the figure, the cover plate surface 14 extends along the conical surface K ₁ , which has an opening angle of 2α. The base plate surface 24 extends analogously along the conical surface K ₂ , which has an opening angle of 2β. In the illustrated example, this is α <β, wherein these two angles could be designed in a modified embodiment substantially the same.

An inventive stator blade segment 10 for a turbomachine comprises a radially inner cover plate 13 with a cover plate surface 14 which is adapted to be arranged in the turbomachine facing the blade segment 20 facing blade and thereby to extend substantially along a conical surface K ₁ , the cone axis coincides with the axis of rotation A of a rotor shaft 30.

A rotor blade 20 for a turbomachine according to the invention has in a radially inner region a base plate 23 with a base plate surface 24 which is adapted to be arranged in the turbomachine a shroud facing one of the blade adjacent vane row 10 and thereby in Substantially to extend along a conical surface K ₂ , whose cone axis coincides with the axis of rotation A of a rotor shaft 30.

reference numeral

10

vane segment

11

airfoil

12

radially outer cover plate

13

radially inner cover plate

14

Cover plate surface

15

fastener

16

sealing element

20

blade

21

Blade airfoil

23

baseplate

24

Base surface

30

rotor shaft

A

central axis or rotation axis

P

Parallel to A

α

Angle between cover plate surface and A (or P)

2α

Opening angle of K ₁

2β

Opening angle of K ₂

β

Angle between base plate surface and A (or P)

K ₁ , K ₂

Conical surface

Claims (10)

1. Guide vane segment (10) for a turbomachine, comprising a radially inner cover plate (13) that has a cover plate surface (14) which is designed to be arranged in the turbomachine so as to face a rotor blade (20) that is adjacent to the guide vane segment upstream thereof and to extend substantially along a cone lateral surface (K₁), the cone axis of which corresponds to the rotational axis (A) of a rotor shaft (30), wherein the cover plate surface (14) faces the rotor shaft (30) when the guide vane segment is assembled as intended.
2. Guide vane segment according to claim 1, wherein the cone lateral surface (K₁) is at an angle of at most 80°, more preferably at most 60°, even more preferably at most 50°, with respect to the axis (A) of the rotor shaft.
3. Assembly for a turbomachine, comprising a guide vane segment (10) according to one of claims 1 to 3 and a rotor blade (20), wherein the rotor blade (20) has, in a radially inner region, a base plate (23) having a base plate surface (24) which is designed to be arranged in the turbomachine so as to face a shroud of a guide vane row that contains the guide vane segment and is adjacent to the rotor blade and to extend substantially along a cone lateral surface (K₂), the cone axis of which corresponds to the rotational axis (A) of a rotor shaft (30).
4. Assembly according to claim 3, wherein the cone lateral surface (K₂) along which the base plate surface (24) of the rotor blade (20) extends is at an angle of at most 80°, more preferably at most 60°, even more preferably at most 50°, with respect to the axis (A) of the rotor shaft (30).
5. Assembly according to either of claims 3 or 4, wherein the base plate surface (24) faces away from the rotor shaft (30) when the rotor blade is assembled as intended.
6. Assembly according to any of claims 3 to 5, wherein the cone lateral surface (K₁) along which the shroud surface (14) of the guide vane segment (10) extends, and the cone lateral surface (K₂) along which the base plate surface (24) of the rotor blade (20) extends, have substantially the same apex angles (2α, 2β).
7. Turbomachine comprising a guide vane segment (10) according to any of claims 1 to 3 and a rotor blade (20) that is adjacent thereto upstream thereof, wherein the rotor blade (20) has, in a radially inner region, a base plate (23) having a base plate surface (24) which is designed to be arranged in the turbomachine so as to face a shroud of a guide vane row that contains the guide vane segment and is adjacent to the rotor blade and to extend substantially along a cone lateral surface (K₂), the cone axis of which corresponds to the rotational axis (A) of a rotor shaft (30).
8. Turbomachine according to claim 7, wherein the cone lateral surface (K₁) along which the shroud surface (14) of the guide vane segment (10) extends, and the cone lateral surface (K₂) along which the base plate surface (24) of the rotor blade (20) extends, have substantially the same apex angles (2α, 2β).
9. Turbomachine according to either of claims 7 or 8, wherein the cone lateral surface (K₂) along which the base plate surface (24) of the rotor blade (20) extends is at an angle of at most 80°, more preferably at most 60°, even more preferably at most 50°, with respect to the axis (A) of the rotor shaft (30).
10. Turbomachine according to any of claims 7 to 9, the base plate surface (24) faces away from the rotor shaft (30) when the rotor blade is assembled as intended.

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