EP2087208A1

EP2087208A1 - Turbo engine

Info

Publication number: EP2087208A1
Application number: EP07846281A
Authority: EP
Inventors: Alexander Böck
Original assignee: MTU Aero Engines GmbH
Current assignee: MTU Aero Engines AG
Priority date: 2006-11-09
Filing date: 2007-10-30
Publication date: 2009-08-12
Anticipated expiration: 2027-10-30
Also published as: EP2087208B1; WO2008055474A1; DE102006052786B4; EP2087208B9; ATE497088T1; US20100003122A1; DE102006052786A1; CA2666200A1; DE502007006392D1; US8608435B2

Abstract

A turbomachine, especially a gas turbine, includes a rotor having rotating blades and a stator having a housing and guide blades. The rotating blades form at least one rotating blade ring, which at one radially outward lying end adjoins an inner ring or casing ring of the housing, thereby defining a gap therebetween. The casing ring is connected to a support ring via curved walls, which together with the casing ring and the support ring bound a cavity and form a bellowslike structure. By changing the pressure prevailing in the cavity of the respective bellowslike structure, the gap between the casing ring and the radially outward lying ends of the respective rotating blade ring can be pneumatically adjusted.

Description

turbomachinery

The invention relates to a turbomachine, in particular a gas turbine, according to the preamble of claim 1 or 11.

From DE 10 2004 037 955 Al a turbomachine with a stator and a rotor is known, wherein the rotor blades and the stator has a housing and vanes. The rotor-side blades form at least one blade ring, which is adjacent at a radially outer end to a radially inner housing wall of the housing, is surrounded by the same and defines a radial gap with the same. The radially inner housing wall of the housing is also referred to as inner ring or shroud and serves in particular as a carrier for an inlet lining. From DE 10 2004 037 955 Al is also known that the gap between the shroud of the housing and the radially outer end of the or each blade ring to provide a so-called Active Clearance Control can be adjusted or adjusted by means of adjusting devices in its gap, so to automatically influence the gap and to ensure an optimal gap position over all operating conditions. In this case, according to DE 10 2004 037 955 A1, the radially inner housing wall or the outer ring is segmented in the circumferential direction, wherein preferably each segment is assigned a separate actuating device. The adjusting devices are preferably designed as electro-mechanical actuators.

DE 101 17 231 Al discloses a turbomachine with a stator and a rotor, wherein the gap between radially outer ends of the blades and the radially inner housing wall by means of a pneumatic, so compressed air operated, actuator unit of a rotor gap control module can be adjusted. The pneumatic actuator unit of the rotor gap control module disclosed therein has an actuator chamber, a pressure chamber and the actuator chamber and the pressure chamber connecting valves, depending on the prevailing pressure in the actuator chamber sealing elements of the rotor gap control module are inflated so as to pneuma - Active Clearance Control tables to adjust or adjust the gap of the gap between radially outer ends of blades and the outer ring of the housing.

DE 29 22 835 C2 and US 5,211,534 disclose further turbomachinery with a pneumatic or compressed air operated Active Clearance Control.

Thus, the turbomachine according to DE 29 22 835 C2 has a stator and a rotor, wherein the gap between radially outer ends of the blades and an inner ring or shroud of a housing wall can be adjusted pneumatically. For this purpose, the shroud ring is connected via resilient side walls with a support ring, wherein the shroud, the support ring and the side walls form a bellows-like structure. By adjusting the pressure in a cavity defined by the bellows-type structure, the gap between radially outer ends of the blades and the shroud can be adjusted. In this case, according to DE 29 22 835 C2, the resilient side walls are curved several times. The side walls are according to DE 29 22 835 C2 thus seen in the axial direction sections inwardly into the cavity and in sections outwardly arched out of the cavity.

On this basis, the present invention is based on the problem to provide a novel turbomachine with a pneumatic Active Clearance Control.

This problem is solved according to a first aspect of the invention by a turbomachine according to claim 1. After that, in the area of the or each bellows-like structure, each wall connecting the shroud ring to the support ring is, as seen in the axial direction, curved inwardly only into the respective cavity.

According to a second aspect of the invention, this problem is solved by a turbomachine according to claim 11. After that, in the region of the or each bellows-like structure, each wall connecting the jacket ring with the support ring is, in the axial direction, curved outward out of the respective cavity. Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

1 shows a cross section through stator-side modules of a turbomachine according to the invention;

FIG. 2 shows a schematic representation of a bellows-type structure of the turbomachine according to FIG. 1; FIG. and

Fig. 3 is a schematic representation of an alternative bellows-like structure of a turbomachine.

1 shows a partial cross-section through a stator of a compressor 10 of a turbomachine, the stator comprising a housing 11 and a plurality of fixed guide vanes 12. The stator-side guide vanes 12 form so-called vane rings which, viewed in the axial direction, are arranged one behind the other. In Fig. 1, a total of four fixed, stator-side vane rings 13, 14, 15 and 16 are shown.

In addition to the stator, the compressor 10 comprises a rotor, not shown in Fig. 1, wherein the rotor of a plurality of axially arranged behind one another, not shown rotor disks is formed, each rotor disk in the circumferential direction next to each other several, also not shown blades carries. The rotor blades associated, circumferentially juxtaposed blades form so-called blade rings, wherein between each two adjacent Leitschaufelkränzen 13 and 14, 14 and 15 and 15 and 16 are each a non-illustrated blade ring is arranged.

The housing 11 of the stator of the compressor 10 comprises a radially inner housing wall, wherein the radially inner housing wall in the region of each rotor-side, not shown in Fig. 1 blade ring forms a so-called inner ring or shroud 17 and surrounds the respective blade ring radially outward. In addition to the man- Telringen 17 of the radially inner housing wall, the housing 11 further comprises a radially outer housing wall 18th

As already stated, forms the radially inner housing wall in the region of each non-illustrated, rotor-side blade ring a so-called shroud ring 17 which surrounds the blade ring radially outward. Between the radially outer ends of the blades of each blade ring and the respective shell ring 17 while a radial gap is formed, which is subject to considerable changes during operation of the compressor, on the one hand, the blades and the respective shrouds have a different thermal behavior and on the other hand, the blades subject to a change in length due to the centrifugal forces or centrifugal forces acting during operation.

Compliance with defined dimensions of the respective gap between the radially outer ends of the blades of a blade ring and the respective shroud 17 prepares during operation considerable difficulties, however, is to optimize the efficiency of crucial importance.

The present invention now relates to such details, with the aid of which radial gaps between radially outer ends of blade rings and the respective shroud 17 can be accurately maintained.

1, the shrouds 17, which extend between the guide vane rings 13 and 14 and 15 and 16, connected via curved and resilient walls 19 with a support ring 20, wherein the respective support ring 20 between the respective shroud 17 and the radially outer Housing wall 18 is arranged. The respective shroud 17, the support ring 20 and the between the respective shroud 17 and the respective support ring 20 extending, curved walls 19 each form a bellows-like structure 21, which has a cavity 22. The respective bellows-like structure 21 and thus the cavity 22 surrounds in the circumferential direction completely and thus closed the respective blade ring. By changing a prevailing in the respective cavity 22 of the bellows-like structure 21 pressure, the gap between the respective shroud 17 and the radially outer end of the respective blade ring is pneumatically adjustable. With an increase in pressure in the cavity 22 of the respective bellows-like structure 21, the respective radially inner shroud 17 can be pressed radially inward and the respective radially outer support ring 20 radially outward. By reducing the pressure in the cavity 22 of the respective bellows-like structure 21, an opposite deformation of the respective bellows-like structure 21 can be realized.

In the preferred embodiment of Fig. 1, the curved, resilient walls 19 of the bellows-like structures 21 seen in the axial direction are curved only inwardly into the respective cavity 22 inwardly. In the region of a vertex of the curvature wall sections of the respective wall 19 close a relatively obtuse angle α of greater than 90 °. This will be described below with reference to FIG. 2, which shows a schematic representation of a bellows-like structure 21.

Thus, FIG. 2 shows that the wall sections of the respective wall 19 enclose an obtuse angle α in the region of a vertex 29 of the curvature. In such curved walls 19 are superimposed at an increase in pressure in the corresponding cavity 22 of the respective bellows-like structure 21, two effects.

First, due to the pressure increase in the cavity 22, the respective shroud 17 and the respective support ring 20 are pressed apart as viewed directly in the radial direction. Second, this radial disengagement of the respective shroud 17 and support ring 20 is supported by a toggle-like effect of the curved walls 19 or at least not hindered. The curved walls 19 are exposed to essentially exclusively compressive forces. According to Fig. 1 and 2, the respective bellows-like structure 21 has a greater radial extent than axial extent. Preferably, the walls 19 of the respective bellows-type structure 21 have a greater radial extent than axial extent.

In the exemplary embodiment shown in FIG. 1, the curved walls 19 of each bellows-like structures 21 have an approximately constant wall thickness in the radial direction. In contrast, it is also possible that the curved walls 19 seen in the radial direction have a variable wall thickness.

As can also be seen from Fig. 1, the radially inner shroud 17 of each bellows-like structure 21 has a smaller wall thickness than the respective radially outer support ring 20. The support ring 20 of each bellows-like structure 21 is therefore designed with a thicker wall thickness than the respective shroud 17. This ensures that deformations of the bellows-like structure 21 caused by changing the pressure prevailing in the respective cavity 22 act primarily on the shroud 17.

It can further be seen from FIG. 1 that the shroud 17 of each bellows-like structure 21 has a contour 23 curved radially outward and projecting into the respective cavity 22 in a central region viewed in the axial direction.

As a result, it is achieved that upon deformation of the shroud 17 as a result of a pressure change in the cavity 22 of the respective bellows-like structure 21, an outer contour 28 of the shroud 17 is substantially exclusively displaced in parallel, so that a gap between the shroud 17 and the blade ring can be set exactly.

Each bellows-like structure 21 is in each case assigned at least one compressed-air line 24 in order to either introduce compressed air into the respective cavity 22 of the respective bellows-like structure 21 or to discharge it from the same compressed air. For reasons 1 shows such a compressed air line 24 exclusively for the bellows-like structure 21 positioned between the two guide blade rings 13 and 14, as shown in the axial direction. Each bellows-like structure 21 is assigned at least one such compressed air line 24. The more such compressed air lines 24 per bellows-like structure 21 are present, the faster compressed air can be introduced into the respective cavity 24 or derived from the same.

In the embodiment of FIG. 1, a bellows-like structure 21 is arranged between the two guide blade rings 13 and 14 and between the two guide blade rings 15 and 16, between the two Leitschaufelkränzen 14 and 15, however, no such bellows-like structure is present. Rather, as shown in FIG. 1 between the two vane rings 14 and 15 and thus in the region of a rotor blade ring arranged between the same, a sensor unit 25 is arranged.

With the sensor unit 25, at least the radial dimension of the gap between the corresponding blade ring and the shell ring 17 surrounding this blade ring can be measured. Via a signal line 26, the sensor unit 25 transmits a corresponding actual value to a control device, not shown, wherein the control device compares the actual value with a desired value and depending on the pressure prevailing in the cavities 22 of the bellows structures 21 set pressure such that the actual value approaches the target value ,

It can be provided that the compressed air supply into the cavities 22 and the compressed air discharge from the cavities 22 of the bellows-like structures 21 is adjustable via individual valves, so as to adjust the pressure prevailing in the cavities 22 of the two bellows-like structures 21 pressure individually and so each Dimension of the radial gap between the shroud 17 and the corresponding blade ring depending on the respective radial extent of the blade ring individually set. Alternatively, it can be provided to adjust the compressed air supply into the cavities 22 of the bellows-like structures 21 or the compressed air discharge from the same via a common valve. By different radial extensions of the respective blade rings of the compressor 10 required, different deformations of the bellows-like structures 21 are then by an adapted curvature of the curved walls 19 and / or an adapted wall thickness of the curved walls 19 and / or by an adapted radial extent of the bellows-like structures 21 achievable.

1, the two bellows-like structures 21 are each divided by axially extending parting planes in the axial direction, wherein during manufacture, the two axial halves of the bellows-like structures 21 are welded together. Alternatively, it is also possible to divide the bellows-like structures in the radial direction.

According to FIGS. 1 and 2, in the region of each bellows-type structure 21, each wall 19 is curved in the axial direction into the respective cavity 22, viewed in the axial direction.

In contrast, it is also possible, as shown diagrammatically in FIG. 3, that in the region of each bellows-type structure 30, each arched, resilient wall 19 is curved in the axial direction outwardly out of the respective cavity 22. 3 close in the region of a vertex 29 of the curvature wall portions of the respective wall 19 a relatively acute angle ß of less than 90 °.

According to FIG. 3, the wall sections enclosing the angle β of the walls 19 extend essentially in the axial direction. The same as the shroud 17 and the support ring 21 are acted upon by the pressure prevailing in the cavity 22 and thereby support a radial disengagement of the shroud 17 and support ring 20 at a pressure increase in the cavity 22. A in this variant negative-acting toggle-like effect is due to the tips Angle ß almost completely eliminated. The bellows-type structure 30 according to FIG. 3 has a greater axial extent than radial extent, in particular the walls 19 of the bellows-type structure 30 have a greater axial extent than radial extent.

Claims

claims

A turbomachine, in particular a gas turbine, with a stator and a rotor, wherein the rotor blades and the stator comprises a housing and vanes, wherein the rotor-side blades form at least one blade ring, wherein the or each blade ring at a radially outer end to a stator adjacent inner ring or shell ring of the housing is surrounded by the same and limited with the same a gap, wherein the respective shroud is connected to a support ring on curved walls which define a cavity together with the shroud and the support ring and form a bellows-like structure, and wherein, by changing a pressure prevailing in the cavity of the respective bellows-type structure, the gap between the jacket ring and the radially outer end of the respective blade ring is pneumatically adjustable, characterized in that in the region of the or each bellows-like structure (21 ) Each wall (19) viewed in the axial direction is curved inwardly into the respective cavity (22) only in a simple manner.

2. Turbomachine according to claim 1, characterized in that in the region of a vertex (29) of the curvature wall portions of the respective wall (19) include a relatively obtuse angle of greater than 90 °.

3. Turbomachine according to claim 1 or 2, characterized in that the walls (19) have a constant wall thickness.

4. Turbomachine according to claim 1 or 2, characterized in that the walls seen in the radial direction have a variable wall thickness.

5. Turbomachine according to one or more of claims 1 to 4, characterized in that in the region of the or each bellows-like structure (21) of the shroud (17) has a smaller wall thickness than the support ring (20).

6. turbomachine according to one or more of claims 1 to 5, characterized in that in the region of the or each bellows-like structure (21) of the shroud (17) in a mid-range seen in the axial direction in the cavity (22) in a curved contour ( 23).

7. turbomachine according to one or more of claims 1 to 6, characterized in that the or each bellows-like structure is assigned in each case at least one compressed air line (24) to initiate compressed air into the respective cavity (22) or derive from the same.

8. turbomachine according to one or more of claims 1 to 7, characterized in that at least two blade rings each having a bellows-like structure (21) is associated, and that between the two blade rings, each associated with a bellows-like structure (21), at least one Rotor blade is arranged, which is associated with a sensor unit (25), wherein the or each sensor unit (25) measures the radial dimension of the gap in the region of the respective blade ring and transmits a corresponding actual value to a control device, and wherein the control device, the actual value with a setpoint compares and, depending on this, adjusts the pressure prevailing in the cavities (22) of the respective bellows-type structures (21) in such a way that the actual value approaches the desired value.

9. Turbomachine according to claim 8, characterized in that the compressed air supply into the cavities (22) or the compressed air discharge from the cavities (22) is adjustable via a common valve, wherein required by different radial extensions of the respective blade rings, different deformations of the bellows-like structures be achieved by an adapted curvature and / or adapted wall thickness of the curved walls of the respective bellows-like structures.

10. Turbomachine according to claim 8, characterized in that the compressed air supply in the cavities (22) and the compressed air discharge from the cavities (22) is adjustable via individual valves, wherein required by different radial extensions of the respective blade rings, different deformations of the bellows-like structures an individual compressed air supply or compressed air removal can be achieved.

11. A turbomachine, in particular a gas turbine, with a stator and a rotor, wherein the rotor blades and the stator has a housing and vanes, wherein the rotor-side blades form at least one blade ring, wherein the or each blade ring at a radially outer end to a stator adjacent inner ring or shell ring of the housing is surrounded by the same and limited with the same a gap, wherein the respective shroud is connected to a support ring on curved walls which define a cavity together with the shroud and the support ring and form a bellows-like structure, and wherein by changing a pressure prevailing in the cavity of the respective bellows-type structure, the gap between the shroud ring and the radially outer end of the respective blade ring is pneumatically adjustable, characterized in that in the region of the or each bellows-like structure (3 0) each wall (19) in axial Alright seen only outwardly out of the respective cavity (22) is curved out.

12. turbomachine according to claim 11, characterized in that in the region of a vertex (29) of the curvature wall portions of the respective wall (19) include a relatively acute angle of less than 90 °.

13. Turbomachine according to claim 11 or 12, characterized by

Characteristics according to one of claims 3 to 10.