EP1861584B1 - Heat accumulation segment for sealing a flow channel of a turbine engine - Google Patents

Abstract

A heat shield arrangement for local separation of a flow channel within a turbine engine, with respect to a stator housing radially surrounding the flow channel is provided. The heat shield includes two axially opposite joining contours which are each engageable with two components which are axially adjacent along the flow channel. Each provides a complementary reception contour for the joining contours. At least one of the reception contours has an axial clearance, in which the associated joining contour is axially displaceably mounted. At least one seal is provided between the axially displaceable joining contour and the reception contour. The seal is mounted movably within the reception contour or the joining contour in such a way that the seal is deflectable against a surface region of the reception contour or of the joining contour.

Description

Technical area

The invention relates to a heat recovery segment for local separation of a flow channel within a flow rotating machine, in particular a gas turbine plant, opposite to a stator radially surrounding the stator housing, with two axially opposite joining contours, which are each engageable with two along the flow channel axially adjacent components, the to the joining contours each provide a gegenkonturrierte receiving contour, of which at least one receiving contour has an axial play, along which the joined joining contour is axially displaceable, wherein between the axially displaceable joining contour and the receiving contour at least one sealing means is provided.

State of the art

Heat accumulation segments of the type described above are part of axial flow-through turbomachines through which flow for compression or targeted expansion gaseous working media and due to their high process temperatures, the thermally heavily loaded with the hot working fluids system components. In particular, in the turbine stages of gas turbine plants in the rows of blades and vanes axially one behind the other arranged blades and vanes are acted upon directly with the resulting hot combustion gases in the combustion chamber. To prevent the hot gases flowing through the flow channel areas load thermally within the flow rotating machine, which are provided in the flow channel remote stator, so-called heat accumulation segments which are provided on the stator side between each two axially adjacent rows of vanes, for a gas-tight as possible bridge-like seal between two axially adjacent arranged guide blade rows. Correspondingly designed heat accumulation segments can also be provided along the rotor unit, which are each mounted on the rotor side between two axially adjacent rotor blade rows in order to protect co-rotating rotor components from too high a heat input.

Although the following statements relate exclusively to heat accumulator segments, which are arranged between two rows of stator blades and insofar able to separate the stator housing and the components associated therewith against the heat-stressed flow channel and protect accordingly, it is also conceivable to provide the following measures on a heat shield segment, serves the protection co-rotating rotor components and between two axially adjacent to each other arranged rows of blades can be introduced.

In FIG. 1 is a schematic longitudinal section shown by a gas turbine stage, in the flow channel radially projecting from the outside with a stator housing S, the special design further has no further significance, associated guide vanes 1.

Between two adjacent guide vanes arranged in rows of blades 1 protrudes connected to a rotor unit, not shown, a blade 2, which is spaced radially from the end face against a heat shield segment 3, which includes the smallest possible clearance gap 4 with the vane 2 to leakage losses with respect to flow components of the hot gas flow through avoid the intermediate gap 4 as possible. For this purpose, the blade tip Sealing structures 5, which are arranged freely rotating relative to so-called abrasion elements 6.

In order to avoid that hot combustion gases in the region of the heat accumulation segment 3, which bridges the intermediate space between two guide vanes 1, 1 'arranged axially adjacent to one another, can reach the region of the heat staging segment 3 remote from the flow passage, the heat staging segment 3 sees two axially opposite one another Join contours 7, 8, which open axially into corresponding receiving contours 9, 10 within the Leitschaufelfüsse.

The receiving contour 9 corresponds to a precisely matched to the joining contour 7 gegenkonturriert running groove-shaped recess which is incorporated in the foot region of the guide vane 1. The axially opposite joining contour 8 of the heat shield segment 3 is likewise inserted into a receiving contour 10 which is counter-contoured corresponding to the outer contour of the joining contour 8 and is inserted in the foot region of the guide blade 1 '. However, the receiving contour 10 has an axial play 11, so that the joining contour 8 is axially slidably mounted with a corresponding operational thermal expansion of the heat shield segment 3.

For fluid-tight sealing of the heat accumulation segment 3 with respect to the respective receiving contours 9, 10 in the foot regions of the guide vanes 1, 1 ', sealing means 12, 13 are provided between the joining contours 7, 8 and the associated receiving contours 9, 10. The sealing means 12, 13 are each located in a groove-shaped recess 14 within the joining contours 7, 8 (see also detailed representation according to FIG Fig. 2b the joining region between the joining contour 8 and the receiving contour 10). The sealing means 12, 13 are preferably made of an elastic sealing material in the form of a round rod, partially project beyond the radially outer boundary surface 16 and nestle flush, at least along a joint line to the surface portion 17 of the receiving contour 10 at.

By the sealing effect of the sealing means 12, 13 can be avoided on the one hand, that hot gases from the flow channel in the radially remote from the flow channel areas penetrate to the heat shield segment 3, also prevents stator-fed cooling air L can pass through appropriate leakage points in the flow channel. As already explained at the beginning, the clearance 11 provided in the recess 11 serves for a thermally induced material expansion along the heat shield segment 3, whereby the joining contour 8 together with the sealing means 12 provided in it is displaced to a right position shown in the illustration. If, on the other hand, the gas turbine stage is switched off and the individual components cool down, the joining contour 8, together with the sealing means 12 provided in it, returns to the original starting position. It is obvious that the sealing means 12 is subject by the thermally induced relative movements between the receiving contour 8 and the surface region 17 Materialabrieberscheinungen that leads to a wear-related reduction of the sealing function of the sealant when exceeding a maximum allowable limit, so that cooling air L through the adjusting or existing intermediate gaps between the joining contour 8 and the receiving contour 10 can escape. This not only leads to a considerable loss of cooling air, whereby the cooling effect is drastically reduced, however, there is a risk that hot gases may also enter areas that are located facing away from the flow channel to the heat shield segment 3. In addition, usually sealing means are used, which consist of a fabric material which can be thinned at high mechanical rubbing stress, whereby the sealing effect of the sealant decreases with increasing operating time.
The US 5423659 alternatively discloses a heat shield assembly in which by flexible, so-called "W seals", an axial gap between the stator and heat shield segment is sealed. By the axial direction of the spring force of the seal, the heat dissipation segment is held in position.

Presentation of the invention

The invention is based on the object, a heat dissipation segment for local separation of a flow channel within a flow rotating machine, in particular a gas turbine plant, opposite to a radially surrounding the flow channel stator housing, with two axially opposite joining contours, the each in engagement with two along the flow channel axially adjacent components can be brought, which provide for the joining contours each have a gegenkonturrierte receiving contour, of which at least one receiving contour has an axial play along which the joining contour is axially slidably mounted, wherein between the axially displaceable Joining contour and the receiving contour at least one sealing means is provided to form such that the sealant should experience no or significantly lower Abriebeigenschaften caused by the thermally induced material expansion and shrinkage caused relative movements between the joining contour and the receiving contour. In particular, it is necessary to take precautions which considerably reduce the wear of the sealant, although the measures to be taken for this purpose should be constructively as simple as possible. Finally, it is essential to extend the maintenance cycles of the maintenance-subject components on the heat recovery segment, in particular the sealant, to significantly improve their reliability.

The solution of the problem underlying the invention is specified in claim 1. The concept of the invention advantageously forming features are the subject of the dependent claims and in particular the description with reference to the further embodiment refer.

According to the solution, a heat damper arrangement according to the features of the preamble of claim 1 is designed such that the sealing means is movably mounted within the receiving contour or the joining contour such that the sealing means can be deflected against a surface region of the receiving contour or the joining contour.

The solution according to the invention provides that the sealing means, which is preferably made of a metallic material, preferably of an incompressible material, as it were introduced in the prior art within a recess along the receiving contour or joining contour, but additionally subjected to a force, Preferably spring-loaded against a surface area of the receiving contour or joining contour to deflect or press. The following considerations provide for integrating the sealing means in the joining contour of the heat spreader segment, so that the sealing means is pressed against a surface area of the receiving contour by a spring force. Likewise, however, it is also possible to integrate the sealing means in a corresponding recess provided within the receiving contour, so that the sealing means is pressed against a surface region of the joining contour. The choice of the attachment of the sealant is the respective structural conditions of the joint connection between the heat shield segment and the axialwärts subsequent component of the gas turbine plant left. Without restricting to the general idea of the invention, the sealant formation according to the invention will be described below as an integral part of the joining contour of the heat recovery segment. In this context, reference is made to the embodiment described in the figures.

Brief description of the invention

Fig. 1 a

schematisierte Teil-Längsschnittdarstellung durch einen Fügebereich zwischen einem Wärmestausegment und einer axialwärts angren- zenden Leitschaufel,

Fig. 1 b

perspektivische Darstellung des Dichtelementes mit Federelement in senkrechter Projektion über einer Ausnehmung innerhalb der Fügekontur,

Fig. 2a, b

Längsschnittteildarstellung durch ein Wärmestausegment mit axial angrenzenden Leitschaufeln sowie Detailldarstellung hierzu gemäss Stand der Technik.

The invention will now be described by way of example without limitation of the general inventive idea by means of embodiments with reference to the drawings. Show it:

Fig. 1 a

Schematic partial longitudinal section through a joining region between a heat shield segment and an axially adjacent guide vane,

Fig. 1 b

perspective view of the sealing element with spring element in a vertical projection over a recess within the joining contour,

Fig. 2a, b

Longitudinal section of a heat recovery segment with axially adjacent vanes and a detailed illustration of this according to the prior art.

Ways to carry out the invention, industrial usability

FIG. 1a shows a partial view through a longitudinal section of a heat shield segment 3 in the region of the joining contour 8, which opens into a corresponding groove-shaped receiving contour 10 of an axially adjacent foot of a guide vane 1 '. The axial depth of the receiving contour 10 is dimensioned so to speak to the prior art described above such that in thermally induced material expansion of the heat shield segment 3, the joining contour 8 along the axially oriented game 11 is slidably mounted. The joining contour 8 consequently carries out a translational movement indicated in the direction of the arrow E. In the in FIG. 1 a illustrated embodiment, the joining contour 8 has a radially outer joining surface 16, in which a groove-shaped recess 14 is incorporated. The depth of the groove-shaped recess 14, measured from the joining surface 16 corresponds at least to the maximum radial extent of the sealing means 12, whose shape is adapted to the inner contour of the groove-shaped recess 14, so that the sealing means 14 can be completely inserted into the recess 14. Further, a spring element 18 is provided within the groove-shaped recess 14, which is introduced between the groove bottom of the recess 14 and the sealing means 12, so that the spring element 18 is able to drive the sealing means 12 radially upwards. For a supplementary overview of the design of the sealing means 12, the spring element 18 and the groove-shaped recess 14 within the joining contour 8, reference is made to the perspective view FIG. 1 b, whose consideration in the following together with FIG. 1 a is to be made.

The sealant 12 is in the in FIG. 1b Perspective manner shown rod-shaped and preferably made of an incompressible metallic material, which has substantially no Abriebeigenschaften. The sealing means 12 has a rectangular design in the middle Projection 19, which engages in a corresponding rectangular recess 20 in the inserted state within the groove-shaped recess 14. The sealing means 12 is forced radially linearly by the projection 19, so that slippage of the sealing means 12 in the circumferential direction along the groove-shaped recess 14 is avoided. Between the sealing means 12 and the bottom of the groove-shaped recess 14 a swung formed spring element 18 is introduced, which is capable of pressing the sealing means 12 radially upward Federkraftbeaufschlagt. In order to prevent the spring element 18 from slipping in the circumferential direction along the groove-shaped recess 14, the curved spring element section 18 'facing the groove bottom opens into a recess (not shown) inserted correspondingly in the groove bottom.

The rectangular shaped recess 20 axially opposite boundary wall 21 within the groove-shaped recess 14 is made of a sealing material and is able to produce in this way in a fluid-tight contact with the sealant 12.

In FIG. 1 a is the inserted state of the joining contour 8 shown within the receiving contour 10, wherein the spring element 18, the sealant 12 radially outwardly against a surface portion 17 of the receiving contour 10 presses and thus the heat shield segment 3 fluid-tight against the receiving contour 10th within the foot of the vane 1 'presses. In order to ensure that the sealing means 12 both on the one hand kraftbeaufschlagt against the surface portion 17 and the back against the boundary wall 21 is pressed, the radially lower side edge of the sealant 12 is formed inclined, so that the spring element 18, the sealant 12 also axially against the rear Limiting surface 21 can press fluid-tight.

In order to improve the sealing effect of the sealant 12 against the surface area 17 of the receiving contour 10, the side edge of the sealant facing the surface area 17 is contoured to the surface area 17.

Although the sealing system made in accordance with the invention can not avoid the axial longitudinal movement of the thermal damper segment 3 due to the thermal material expansion or shrinkage, the material abrasion completely disappears with a suitable choice of the sealant material, especially since the sealant 12 is made of an incompressible, wear-free, preferably metallic material is selected, which ensures a fluid-tight seal due to the spring-loaded pressure.

It is also conceivable that the spring-loaded sealant arrangement instead of in FIGS. 1a and b specified manner within the joining contour 8 alternatively provided in the region of the receiving contour 10.

Furthermore, the cooling air L flowing in under high pressure can exert a high contact pressure on the axially directed surface 23 of the projection 19 within the cooling volume V enclosed by the thermal damper segment 3, so that the sealing means is pressed in the axial direction in addition to the spring force component against the sealing side 21 consisting of sealing material ,

In addition to the in the FIGS. 1a and b illustrated concrete embodiment of the spring element 18 are also other spring element designs conceivable, such as a plurality of individual spiral spring elements, helically shaped or coiled spring elements and suitably shaped flat springs.

For the sake of completeness, it should also be noted that in FIG. 1 a and b illustrated heat shield segment in a ring-like array the entire peripheral area between two adjacent limited to each other Leitschaufelreihen. For this purpose, two heat accumulation segments arranged adjacent to one another in the circumferential direction engage via a common strip band seal 24, by means of which a possible loss of cooling air along two circumferentially adjacent heat accumulation segments can be avoided.

• Die Dichtheit des Kühlluftvolumens, das durch das Wärmestausegment vom Strömungskanal abgetrennt wird, wird aufgrund des abnutzungsfreien Dichtmittels erheblich verbessert, zumal die Dichtwirkung trotz thermischer Ausdehnungs- und Schrumpfungserscheinungen durch die federkraftbeaufschlagte Anpressung des Dichtmittels an den jeweiligen dem Dichtmittel gegenüberliegenden Oberflächenbereich gewährleistet wird.

The solution according to the seal assembly is thus associated with the following advantages:

• The tightness of the cooling air volume, which is separated by the heat discharge segment from the flow channel is significantly improved due to the wear-free sealant, especially since the sealing effect is guaranteed despite thermal expansion and shrinkage phenomena by the spring-loaded contact pressure of the sealant to the respective surface area opposite the sealant.

Regardless of predetermined tolerances with respect to the execution of the receiving contour or the joining contour, the spring-pressure of the sealant ensures at any time a sealing of the joining area with respect to its radially upper and lower boundary surfaces, especially since the radially upper sealing means 12 by the force exerted on the joint counterforce and the radially lower boundary surface of the joining region against the boundary surface of the receiving contour 10 can press fluid-tight. If the sealing means be provided in the region of the boundary surface of the receiving contour 10, the same applies accordingly.

Due to the spring-loaded pressing action of the sealing means 12 against the surface region 16 of the receiving contour 10, the spring element 18 carries due its inherent elasticity to a certain capacity at impact or vibration absorption, so that occurring mechanical shocks within the joint area can be absorbed by the spring element 18 and thus not too strong mechanical stress on the joint area.

Reference number list

1, 1 '

vane

2

blade

3

Heat shield

4

intermediate gap

5

ribs

6

abrasion elements

7, 8

joining contour

9.10

Up Silhouette

11

axial play

12, 13

sealant

14

groove-shaped recess

15

N. N.

16

joining surface

17

surface area

18

spring element

18 '

Part of the spring element

19

projection

20

recess

21

boundary surface

23

radial side surface of the projection

Claims (6)

1. Arrangement containing a heat shield and at least one sealing means (12) for the local separation of a flow channel within a turbine engine, in particular gas turbine plant, with respect to a stator housing radially surrounding the flow channel, with two axially opposite joining contours (7, 8) which can be brought in each case into engagement with two components (1, 1') which are axially adjacent along the flow channel and which in each case provide a countercontoured reception contour (9, 10) for the joining contours (7, 8), of which reception contours at least one reception contour (10) has an axial clearance (11), along which the joining contour (8) joined in it is mounted axially displaceably, the at least one sealing means (12) being provided between the axially displaceable joining contour (8) and the reception contour (10) and the sealing means (12) being mounted movably within the reception contour (10) or the joining contour (8) in such a way that the sealing means (12) can be deflected against a surface region (17) of the reception contour (10) or of the joining contour (8), characterized in that the reception contour (10) or the joining contour (8) has a joining face (16) in which is introduced for the sealing means (12) a recess (14) out of which the sealing means (12) can be deflected so as to project partially beyond the joining face (16) and at least one spring element (18), which deflects the sealing means (12) by the action of spring force, is provided in the recess (14).
2. Arrangement containing a heat shield according to Claim 1, characterized in that the sealing means (12) consists of a metallic material.
3. Arrangement containing a heat shield according to Claim 1 or 2, characterized in that the sealing means (12) is a solid body with incompressible properties.
4. Arrangement containing a heat shield according to one of Claims 1 to 3, characterized in that the sealing means (12) is of bar-shaped design and has a local protrusion (19) along its extent, and in that a recess (20), which is adapted to the protrusion (19) and along which the protrusion (19) is guided in the radial direction, is provided in the recess (14).
5. Arrangement containing a heat shield according to one of Claims 1 to 4, characterized in that the spring element (18) is designed as a curved bar spring and is held in the longitudinal direction with respect to the recess (14).
6. Arrangement containing a heat shield according to one of Claims 2 to 5, characterized in that the recess (14) has a radially oriented boundary face (21) which consists of a sealing material, in that the sealing means (12) has a radially upper side edge which is adapted to the surface region (17) against which the sealing means (12) can be pressed by the action of force, and in that the sealing means (12) has a radially lower sloped side edge, against which the spring element (18) presses, and the inclination of the slope is selected in such a way that the sealing means (12) can be pressed both against the surface region (17) and against the boundary face (21) consisting of the sealing material.

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