DE102016123248A1 - gas turbine - Google Patents

Abstract

The invention relates to a gas turbine having at least one disc (5), wherein turbine blade elements (1) are connected to the at least one disc (5) via connecting means (2), characterized in that the connecting means (2) are arranged inside the turbine blade elements (1). in the radial extent of the turbine blade elements (1) in a region (H) are arranged radially above the disc (5), in particular in a region (H1) are arranged, which is in the driving air flow (L) during operation of the gas turbine (100).

Description

The invention relates to a gas turbine with the features of claim 1.

Gas turbines, such as e.g. Aircraft engines or stationary gas turbines are thermally and mechanically highly loaded units.

The efficiency of a gas turbine is greatly influenced by the thermal and mechanical strength of the gas turbine. It is in the art, for example, from the WO 2012 160819 A1 known to connect the turbine blades form fit via a so-called Fannenbaumfuß with a turbine disk.

This positive connection requires a considerable volume of material and significantly affects the weight and the load capacity of the gas turbine. When compared with compressor designs, it can be estimated that, compared to an integral blisk design, about 30% of the total weight of a stage is needed for positive engagement. Apart from the application in small shaft power engines, a blisk design is not sensible and not common due to very different material requirements of turbine blade and turbine disk.

There is therefore the task of adapting gas turbines to the particular conditions of use.

This object is achieved by a gas turbine with the features of claim 1.

The gas turbine has at least one disc, wherein turbine blade elements are connected via connecting means with the at least one disc.

The connecting means are arranged in the interior of the turbine blade elements, wherein the turbine blade elements are arranged in the radial extension in a region radially above the disc, in particular in a region are arranged, which is in the operation of the gas turbine in the driving air flow.

The connecting means are thus in particular in a region of the turbine blade elements, which are exposed to the hot gas flow, i. in the aerodynamically effective area (aerofoil area) of the turbine blade elements. Thus, the connecting means are arranged in a region in which comparatively small masses must be transmitted.

Thereby, e.g. the cores for the turbine blade elements are integrally materially made of the disc. Only in a radial area, which is in operation in the hot gas stream, is the positive connection to the enveloping Aerofoilbereich. This leads to an approx. 70% reduction in mass, which must be transferred via the form fit and to a considerable reduction of stress in the aerofoil range. Tensile stresses only occur in the blade region lying radially outside the positive connection. The area lying radially below is subjected to compressive stress.

Another aspect of such a design is improved gap control (i.e., gap distance between blade tip and surrounding housing) due to less thermal and elastic expansion due to design.

In one embodiment, the connecting means are arranged radially inward, radially in the middle or radially outward in the region radially above the disk, in particular in the region of the turbine blade elements, which lies in the driving air flow during operation of the gas turbine.

In principle, it is possible that the connecting means are formed positively, non-positively and / or cohesively.

Forming means, in particular projections, projections and / or undercuts for axial and / or radial fixing of the turbine blade elements can be used in embodiments for forming the positive connection means.

Non-positive connection means may have a wedge connection, in particular in the disc and / or shrink joints to achieve a frictional connection.

Cohesive connection means may have a laser weld between the turbine blade elements and the disk.

The turbine blade elements may also have at least two zones of different materials, the at least two zones joining one another, in particular in the radial direction. Thus, the materials can be selected according to load. In this case, at least one separating line can be arranged between the at least two zones of different material in the turbine blade elements radially below the connecting means.

Thus, in one embodiment, radially below the connecting means, a zone with a material suitable for compression stress, in particular a ceramic, in particular a yttrium stabilized zirconia, be arranged. Alternatively or additionally, a zone with a tension-suitable material, in particular CMSX 4, can be arranged radially above the connecting means.

Also wedge elements for bracing the disc with the turbine blade elements and / or for establishing a positive connection between the disc and the turbine blade elements. The material of the core is then e.g. more elastic than the material of the wedge means. The wedge means pushes the core e.g. against the inside of the turbine blade elements.

For connecting the turbine blade elements with the cores may be arranged radially outside a welded joint.

The turbine blade elements may consist of two parts, whereby only in the assembly of the parts the positive connections are made.

The gas turbines can be designed as an aircraft engine, as a vehicle drive, as a marine propulsion or stationary gas turbine.

The turbine blade elements or the disc can be particularly adapted and designed for use according to at least one of claims 1 to 15.

• 1 eine schematische Darstellung einer Gasturbine, hier eine Flugzeugturbine;
• 2A eine horizontale Schnittansicht durch ein Turbinenschaufelelement;
• 2B eine Schnittansicht durch das Turbinenschaufelelement gemäß 2A entlang der Linie A-A;
• 3A eine alternative Ausgestaltung des Turbinenschaufelelements mit einem Keilmittel zur Montage eines Turbinenschaufelelements;
• 3B die Ausgestaltung nach 3A mit einem eingetriebenen Keilmittel zur Fixierung des Turbinenschaufelelements mittels Formschluß;
• 4A eine alternative Ausgestaltung des Turbinenschaufelelementes mit einer Scheibe ohne Keilmittel;
• 4B eine alternative Ausgestaltung des Turbinenschaufelelementes mit einer Scheibe mit einem Keilmittel zur Verspannung des Turbinenschaufelelementes mit der Scheibe.

In connection with the embodiments illustrated in the figures, the invention will be explained. It shows

• 1 a schematic representation of a gas turbine, here an aircraft turbine;
• 2A a horizontal sectional view through a turbine blade element;
• 2 B a sectional view through the turbine blade element according to 2A along the line AA;
• 3A an alternative embodiment of the turbine blade element with a wedge means for mounting a turbine blade element;
• 3B the design after 3A with a driven wedge means for fixing the turbine blade element by means of positive engagement;
• 4A an alternative embodiment of the turbine blade element with a disc without wedge means;
• 4B an alternative embodiment of the turbine blade element with a disc with a wedge means for clamping the turbine blade element with the disc.

As in 1 shown, are the individual components of the gas turbine 100 along a rotation axis or center axis M arranged one behind the other, the gas turbine 100 is designed as a turbofan engine. At an inlet or intake e the gas turbine 100 becomes air along an entry direction R by means of a fan F sucked. This one in a fan case FC arranged fan F is driven by a rotor shaft S from a turbine TT the gas turbine 100 is set in rotation. The turbine TT closes here to a compressor V on, for example, a low-pressure compressor 11 and a high pressure compressor 12 having. The fan F leads the compressor V and the bypass channel B Air too. The bypass channel B in this case runs around the compressor V and the turbine TT comprehensive core engine, which has a primary flow channel for the fan F the core engine supplied air includes.

The over the compressor V Air delivered into the primary flow channel enters a combustion chamber section BK of the core engine, where the drive power to power the turbine TT is produced. The turbine TT has a high-pressure turbine for this purpose 13 , a medium pressure turbine 14 and a low-pressure turbine 15 on. The low pressure turbine 15 it drives the rotor shaft S and thus the fan via the energy released during combustion F to go over in the bypass channel B conveyed air to produce the required thrust. Both the air from the bypass channel B as well as the exhaust gases from the primary flow channel of the core engine flow through an outlet A at the end of the engine T out. The outlet A in this case usually has a discharge nozzle with a centrally arranged discharge cone C on.

Both in the area of the (axial) compressor with its low-pressure compressor 11 and its high pressure compressor 12 as well as in the area of the turbine TT are known to be around the central axis M rotating blade assemblies used, each having a row of blades and in which the blades are provided on an annular or disc-shaped blade carrier. The ring-shaped or disk-shaped blade carrier can in principle be integrally bladed and thus be manufactured in bling or blisk construction. Alternatively, the fixing of individual blades via their respective blade root on a ring-shaped or disk-shaped blade carrier is possible.

The embodiments of the invention presented below relate to the connection of the rotor blades in the region of the turbine TT the gas turbine 100 ,

In 2A is a horizontal sectional view through a blade, here a Turbine bucket member 1 represented. The turbine blade element surrounds this 1 inside a core 4 that is integral with a washer 5 the turbine TT connected is. This is more accurate in the sectional view of 2 B recognizable.

The disc 5 indicates the core 4 on the inside of the turbine blade element 1 protrudes. The connection between the disc 5 and the turbine blade element 1 takes place here via a positive connection means 2 inside the turbine blade element 1 , In this case, the connection means 2 in the embodiment shown here a positive locking means 3 on, with which the turbine blade element 1 is fixed axially and / or radially. A positive connection means 2 can with non-positive and / or material connection means 2 be combined.

The positive locking means 3 is here at the radially outer edge of the core 4 formed as a mushroom-shaped formation that forms a paragraph. Inside the turbine blade element 1 a corresponding projection is formed, which coincides with the shoulder of the positive locking means 3 at the core 4 engaged. The positive locking means 3 may also have an undercut, for example.

In operation, due to the centrifugal force considerable radial forces act on the turbine blade elements 1 , The positive connection 2 is therefore designed to hold these radial forces. A typical weight for a turbine blade element 1 in an aircraft engine is between 50 and 150 g. For stationary gas turbines, the weight can be significantly higher.

The tip of the turbine blade elements 1 extends radially from the write 4 away over a height H ,

In the embodiment shown here is the positive connection means 2 at about half the height of the blade or half of the area H1 of the turbine blade element 1 in the operation of the gas turbine the hot, driving air flow L is exposed. Thus, the turbine blade element 1 in radial extension in two zones Z1 . Z2 to be grouped.

The first zone Z1 extends from the base of the turbine blade element 1 until the positive connection means 2 , The second zone Z2 extends from the positive connection means 2 to the blade tip.

Between the zones Z1 . Z2 In the illustrated embodiment, a dividing line T runs between different materials.

In the first zone Z1 below the positive connection means 2 Above all, compressive stresses act, so that particularly pressure-voltage-resistant materials can be used here. An example of this is, for example, ceramics, in particular a yttrium-stabilized zirconium oxide or CMC (ceramic matrix composites).

• 6,5 Gew-% Cr,
• 5,6 Gew-% Al,
• 1,0 Gew-% Ti,
• 6,5 Gew-% Ta,
• 6,4 Gew-% W,
• 0,6 Gew-% Mo,
• 9,6 Gew-% Co,
• 3,0 Gew-% Re,
• 0,07 Gew-% Hf.

In the second zone Z2 above the positive connection means 2 For example, the monocrystalline material CMSX- 4 used. A typical composition of this nickel base alloy is:

• 6.5% by weight Cr,
• 5.6% by weight of Al,
• 1.0% by weight of Ti,
• 6.5% by weight of Ta,
• 6.4% by weight W,
• 0.6% by weight of Mo,
• 9.6% by weight of Co,
• 3.0% by weight of Re,
• 0.07% by weight Hf.

This material is particularly temperature resistant. In principle, however, other high temperature resistant superalloys in the second zone Z2 be used.

The positive connection means 2 is in the illustrated embodiment substantially at half the height of the turbine blade element 1 arranged. Alternatively, the positive connection means 2 but also closer to the base, ie closer to the disc 5 or closer to the tip of the turbine blade element 1 be arranged.

In 2 B is further shown that cooling air from the area of the disc 5 radially outward into the interior of the turbine blade element 1 can occur.

In 3A FIG. 12 is a detail of one embodiment of a connection between a turbine blade element. FIG 1 and a disc 5 shown. The core 4 the disc 5 has a wedge agent 7 on that in a corresponding gap of the core 4 is recoverable ..

In 3A is the not yet driven position of the wedge means 7 (the core 4 then has a small cross-section) shown. In this condition, the turbine blade element is 1 attachable.

In 3B is a driven position of the wedge means 7 represented, ie the cross section of the core 4 increases, so that a positive connecting means 2 between core 4 and turbine blade element 1 will be produced.

In the 4A and 4B a further alternative embodiment is shown. Here is the wedge agent 7 used a non-positive connection means 2 between the core 4 the disc 5 manufacture.

In 4A is shown a sectional view in which the core 4 without the tensioning wedge means 7 is shown. The core 4 has only a prefabricated gap (dashed lines here), in which the tel 7 can be used. In the position shown here, there is no connection to the side walls between the turbine blade elements 1 and the core 4 ,

On the other hand, there is a wedge agent 7 at the core, like in 4B represented, so spreads the core 4 on, leaving on the sidewalls of the core 4 a frictional engagement with the inner sides of the turbine blade element 1 is present.

Such a compound can eg with a positive locking means 3 (as in the in 3A . 3B illustrated embodiments) are combined. It is also possible to produce an integral connection alternatively or additionally.

The configuration according to 3 and 4 can be made so that sleeve-shaped turbine blade elements 1 about the core 4 be placed, ie the turbine blade elements 1 are open at the radially outer end. After fitting, then the positive connection, the frictional connection and / the material connection can be made.

In the 3 and 4 are the turbine blade elements 1 each formed closed at the radially outer edge. This can be done, for example, by welding a cover after the connection has been made, as described above. But it is also possible that the radially outer end remains open, so that in the bottom of the turbine blade elements 1 incoming cooling air K can exit at the top.

LIST OF REFERENCE NUMBERS

1

Turbine bucket member

2

connecting means

3

Fit means

4

core

5

disc

7

Wedge means, wedge connection

11

Low-pressure compressor

12

High-pressure compressors

13

High-pressure turbine

14

Intermediate pressure turbine

15

Low-pressure turbine

100

gas turbine

A

outlet

B

bypass channel

BK

combustor section

C

exit cone

e

Inlet / Intake

F

fan

FC

fan casing

H

Height of turbine blade tip measured radially from the disk

H1

Area of the turbine blade in the air stream

K

cooling air

L

driving airflow

M

axis of rotation

R

entry direction

T

parting line

TT

turbine

V

compressor

Z1

first zone

Z2

second zone

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2012160819 A1 [0003]

Claims (15)

Gas turbine with at least one disc (5), wherein turbine blade elements (1) via connecting means (2) with the at least one disc (5) are connected, characterized in that the connecting means (2) in the interior of the turbine blade elements (1) in the radial extent of Turbine blade elements (1) in a region (H) radially above the disc (5) are arranged, in particular in a region (H1) are arranged, which is in the operation of the gas turbine (100) in the driving air flow (L). Gas turbine after Claim 1 , characterized in that the connecting means (2) radially inward, radially in the middle or radially outside in the region (H) radially above the disc (5), in particular in the region (H1) of the turbine blade elements (1) are arranged, which is in operation the gas turbine (100) in the driving air flow (L) is located. Gas turbine after Claim 1 or 2 , characterized in that the connecting means (2) are formed positively, positively and / or cohesively. Gas turbine after Claim 3 , characterized in that the positive connection means (2) positive engagement means (3), in particular lugs, projections and / or undercuts for axial and / or radial fixing of the turbine blade elements (1). Gas turbine after Claim 3 , characterized in that in non-positive connection means (2) via a wedge connection (7), in particular in the disc (5) and / or shrink joints a frictional engagement can be achieved. Gas turbine after Claim 3 , characterized in that in material-locking connection means (2) a laser welding connection between the turbine blade elements (1) and the disc (5) is present. Gas turbine according to at least one of the preceding claims, characterized in that the turbine blade elements (1) have at least two zones (Z1, Z2) made of different materials, wherein the at least two zones (Z1, Z2) adjoin one another, in particular in the radial direction. Gas turbine after Claim 7 , characterized in that at least one parting line (T) between two zones (Z1, Z2) of different material in the turbine blade elements (1) is arranged radially below the connecting means (2). Gas turbine after at least one of Claims 7 or 8th , characterized in that radially below the connecting means (2) a zone (Z1) with a pressure-voltage-suitable material, in particular a ceramic, in particular a yittrium-stabilized zirconium oxide, is arranged. Gas turbine after at least one of Claims 7 to 9 , characterized in that radially above the connecting means (2) a zone (Z2) with a zugspannungsgeeignetem material, in particular CMSX 4, is arranged. Gas turbine according to at least one of the preceding claims, characterized by wedge elements (7) for clamping the disc (5) with the turbine blade elements (1) and / or for producing a positive connection between the disc (5) and the turbine blade elements (1). Gas turbine according to at least one of the preceding claims, characterized in that the turbine blade elements (1) are connected radially outside via a welded connection with the at least one disc (5). Gas turbine according to at least one of the preceding claims, characterized in that the turbine blade elements (1) can be assembled from at least two parts. Gas turbine according to at least one of the preceding claims, characterized in that it is designed as an aircraft engine, as a vehicle drive, as a marine propulsion or stationary gas turbine. Turbine blade element (1) or disc (5), specially adapted and adapted for use in a gas turbine (100) according to at least one of Claims 1 to 14 ,

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