EP2344723B1 - Gas turbine with seal plates on the turbine disk - Google Patents

Description

The invention relates to a turbine rotor with a number of each combined into blade rows, arranged on each turbine disk rotor blades, wherein the respective turbine disk has on its side surfaces a number of annular ring-shaped sealing plates which are inserted in an azimuthally extending turbine disk groove, wherein the respective sealing plate to the side facing the turbine axis has an azimuthally extending, spaced from the inner edge of the respective sealing plate edge.

Gas turbines are used in many areas to drive generators or work machines. In this case, the energy content of a fuel is used to generate a rotational movement of a turbine rotor. For this purpose, the fuel is burned in a combustion chamber, compressed air being supplied by an air compressor. The working medium produced in the combustion chamber by the combustion of the fuel, under high pressure and at high temperature, is guided via a turbine unit arranged downstream of the combustion chamber, where it relaxes to perform work.

To generate the rotational movement of the turbine rotor, a number of rotor blades, which are usually combined into blade groups or blade rows, are arranged thereon. In this case, a turbine disk is usually provided for each turbine stage, to which the blades are fastened by means of their blade root. For guiding the flow of the working medium in the turbine unit also commonly associated between adjacent blade rows with the turbine housing and combined into rows of guide vanes are arranged.

The combustor of the gas turbine may be embodied as a so-called annular combustor in which a plurality of burners circumferentially disposed about the turbine rotor discharge into a common combustor chamber surrounded by a high temperature resistant surround wall. For this purpose, the combustion chamber is designed in its entirety as an annular structure. In addition to a single combustion chamber can also be provided a plurality of combustion chambers.

Immediately adjoining the combustion chamber is generally followed by a first row of guide vanes of a turbine unit which, together with the blade row immediately downstream in the flow direction of the working medium, forms a first turbine stage of the turbine unit, which is usually followed by further turbine stages.

In the design of such gas turbines in addition to the achievable power usually a particularly high efficiency is a design target. An increase in the efficiency can be achieved for thermodynamic reasons basically by increasing the outlet temperature, with the working medium from the combustion chamber off and flows into the turbine unit. Temperatures of about 1200 ° C to 1500 ° C for such gas turbines are sought and achieved.

At such high temperatures of the working medium, however, exposed to this components and components are exposed to high thermal loads. In order to protect the turbine disk against contact of hot working fluid and to guide cooling air along the side surfaces of the rotor disk to the rotor blades, sealing plates are usually provided on the turbine disks, which are circularly mounted circumferentially on the turbine disk on the side surfaces normal to the turbine axis. In this case, a sealing plate is usually provided per turbine blade on each side of the turbine disk. These overlap like scales and usually have one Sealing wings, which extends to the adjacent vane so that the penetration of hot working medium in the direction of the turbine rotor is avoided.

However, the sealing plates fulfill even more functions. On the one hand they form the axial fixation of the turbine blades by appropriate fasteners, on the other hand they not only seal the turbine disk against penetration of hot gas from the outside, but also avoid the escape of the guided inside the turbine disk cooling air, which usually forwarded to the cooling of the turbine blades in selbige becomes. A gas turbine in such a configuration is for example from the EP 1 944 471 A1 known.

However, the above-mentioned embodiment of the turbine disks with segmented imbricated overlapping sealing plates is relatively complicated. It is a relatively large number of sealing plates required, resulting in a relatively high design effort of the turbine disks and thus the entire gas turbine. Furthermore, a possibly required repair in the area of the turbine disks can be comparatively complicated by this construction.

Moreover, from the US 2008/0181767 A1 a fuse for sealing plates of turbine disks, in which the sealing plates have at their inner edge a shoulder, with which they rest sealingly against a laterally encircling projection of the turbine disk. To secure the sealing plates in their final installation position, a closure element is required in each case, which is arranged in a recess of the sealing plate is used simultaneously with this in the turbine disk groove. Subsequently, the closure element of the recess is removed and moved along the turbine disk groove, which then blocks the sealing plate to the turbine disk radially and axially. To secure the closure piece against displacement in the circumferential direction whose pointer between two am Sealing plate provided cams inflected. Overall, however, the simultaneous insertion of sealing plate and closure element is easy to install.

The invention is therefore based on the object to provide a turbine rotor, which allows a simplified design and installation while maintaining the greatest possible operational safety and the greatest possible efficiency when used in a turbine.

This object is achieved according to the invention with a turbine rotor mentioned above, in which between the edge of the respective sealing plate and a side wall of the turbine disc groove closure pieces are arranged, and in which the edge extends over the entire azimuthal length of the sealing plate and the closure pieces for sealing in the azimuthal direction adjacent to each other, wherein the respective sealing plate comprises at least one substantially azimuthally on the side facing the turbine axis, the respective edge interrupting recess which is geometrically designed so that through this the closure pieces are inserted into the turbine disk groove.

The invention is based on the consideration that a simplified construction of the gas turbine, in particular in the area of the turbine disks, would be possible if the hitherto customary construction could be simplified with scale-like sealing plates.

Holes were introduced into the usual scale-like sealing plates, so that they could be fixed to the turbine disk with securing bolts and locking plates. With a smaller number of used sealing plates, however, the individual sealing plates are larger. Therefore, a larger and multiple attachment of the sealing plates on the turbine disk is necessary to a sufficient to ensure axial and radial fixation. Furthermore, the attachment should also provide for a sealing of the remaining gap between the turbine disk and the inner edge (ie, the turbine axis facing edge) of the sealing plate. For this purpose, the respective sealing plate on the turbine axis side facing an azimuthally extending, spaced from the inner edge of the respective sealing plate edge, wherein between the edge and a likewise azimuthally extending turbine disk groove on the turbine disk for sealing a plurality of abutting closure pieces - during the Mounting azimuthally displaceable - is arranged.

In this way, a plurality of closure pieces, for example in the form of beams, can be introduced into the remaining space between the sealing plate and the turbine disk. These are fixed in the radial and axial direction by edge, sealing plate and side wall of the turbine disk groove. In the azimuthal direction, however, they remain displaceable and can thus be arranged adjacent to one another in order to achieve a complete seal by forming a ring of closure pieces.

In the assembled state - as already described - the closure pieces are fixed axially and radially. So that an assembly of the closure pieces is still possible with already applied to the turbine disk sealing plate, the respective sealing plate comprises at least one substantially azimuthally on the side facing the turbine axis side recess which interrupts the edge. This recess is geometrically designed such that a closure piece can be inserted into the turbine disk groove, ie it is just so large that a closure piece can be lowered into the turbine disk groove when the sealing disk is already mounted. There, this closure piece can then be moved azimuthally into its end position, where it is fixed axially by the side wall of the turbine disk groove and the sealing plate and radially by the edge. Further Closures can then be inserted over the same recess and also moved until all the closure pieces are mounted.

The sealing plates are substantially circular section. As a result, the sealing plates are adapted to the shape of the turbine disk and it is thus ensured a reliable seal. The larger, circular segment-shaped sealing plates then cover namely the same area as the previously scaly superimposed individual sealing plates.

In a further advantageous embodiment, two sealing plates are provided per side surface. The simplest embodiment of the sealing plates is namely possible with a maximum reduction of the number of sealing plates, wherein a single sealing plate, for example in the form of a circular ring due to the tilting required during assembly is not possible. Therefore, the simplest possible construction is a design with two identically designed sealing plates. This embodiment is also particularly advantageous for stationary gas turbines, since their assembly of housing and rotor takes place radially and not axially as in aircraft gas turbines.

Advantageously, a slot is introduced into each facing surfaces of two sealing plates, wherein for sealing the gap between the surfaces of the respective opposite slots connecting plate is inserted. Thus, no scale-like overlap is necessary for a reliable seal between the sealing plates, but there are corresponding slots or grooves provided with an inserted checker plate. This then closes in a suitable embodiment, the remaining small gap between the sealing plates.

Advantageously, the respective sealing plate has a substantially azimuthally and axially extending sealing wing on. By such a sealing wing, which should be configured in a correspondingly larger by the smaller number of sealing plate in the azimuthal direction, a seal of the turbine rotor facing part of the turbine disk against penetrating hot gas from the interior of the turbine is achieved. In this case, the sealing wing should extend in the axial direction to the respective adjacent vanes, in order to achieve a particularly good seal.

In a further advantageous embodiment, the respective closure piece has a bore, the respective sealing plate has a number of notches, and the wall delimiting the turbine disk has a bore for receiving a securing bolt. Thus, both the closure pieces and the sealing plate itself can be fixed by a securing bolt and it is a reliable cohesion with simultaneous easy installation possible.

Advantageously, the respective sealing plate is made by turning. The smaller number of sealing plates makes it possible to manufacture the sealing plates as a circular ring in the turning process and then to divide. As a result, a simplified and more cost-effective production of the sealing plates is possible.

Advantageously, such a gas turbine is used in a gas and steam turbine plant.

The advantages associated with the invention are in particular that a substantially simplified and cheaper construction of the gas turbine is possible by reducing the number of sealing plates per side surface of the turbine disk of a gas turbine. The design of the entire blade row is thereby significantly simplified and is less expensive to manufacture, since the sealing plates can be manufactured in the turning process. In addition, the sealing plates have comparatively few leakage surfaces. This can be sealed much denser to reduce the loss of cooling air.

FIG 1

einen Halbschnitt durch eine Gasturbine,

FIG 2

einen Halbschnitt durch den äußeren Umfang einer Turbinenscheibe für die Gasturbine eine Dichtplatte und deren Fixierungsvorrichtung,

FIG 3-5

eine Dichtplatte in verschiedenen Ansichten,

FIG 6-8

ein Verschlussstück in verschiedenen Ansichten, und

FIG 9-14

die Arbeitsschritte des Montageprozesses.

An embodiment of the invention will be explained in more detail with reference to a drawing. Show:

FIG. 1

a half-section through a gas turbine,

FIG. 2

a half-section through the outer periphery of a turbine disk for the gas turbine, a sealing plate and its fixing device,

3-5

a sealing plate in different views,

FIG 6-8

a stopper in different views, and

FIGS. 9-14

the steps of the assembly process.

Identical parts are provided with the same reference numerals in all figures.

The gas turbine 1 according to FIG. 1 has a compressor 2 for combustion air, a combustion chamber 4 and a turbine unit 6 for driving the compressor 2 and a generator, not shown, or a working machine. For this purpose, the turbine unit 6 and the compressor 2 are arranged on a common turbine rotor 8, also referred to as a turbine rotor, to which the generator or the working machine is also connected, and which is rotatably mounted about its central axis 9. The running in the manner of an annular combustion chamber 4 is equipped with a number of burners 10 for the combustion of a liquid or gaseous fuel.

The turbine unit 6 has a number of rotatable blades 12 connected to the turbine rotor 8. The blades 12 are arranged in a ring shape on the turbine rotor 8 and thus form a number of Blade rows. Furthermore, the turbine unit 6 comprises a number of stationary vanes 14, which are also attached in a donut-like manner to a vane support 16 of the turbine unit 6 to form rows of vanes. The blades 12 serve to drive the turbine rotor 8 by momentum transfer from the turbine unit 6 flowing through the working medium M. The vanes 14, however, serve to guide the flow of the working medium M between two seen in the flow direction of the working medium M consecutive blade rows or blade rings. A successive pair of a ring of vanes 14 or a row of vanes and a ring of blades 12 or a blade row is also referred to as a turbine stage.

Each vane 14 has a platform 18 which is arranged to fix the respective vane 14 to a vane support 16 of the turbine unit 6 as a wall element. The platform 18 is a thermally comparatively heavily loaded component which forms the outer boundary of a hot gas channel for the working medium M flowing through the turbine unit 6. Each blade 12 is attached to the turbine rotor 8 in a similar manner via a platform 19.

Between the spaced-apart platforms 18 of the guide vanes 14 of two adjacent rows of guide vanes, a guide ring 21 is arranged on a guide blade carrier 16 of the turbine unit 6. The outer surface of each guide ring 21 is also exposed to the hot, the turbine unit 6 flowing through the working medium M and spaced in the radial direction from the outer end of the opposite blades 12 through a gap. The guide rings 21 arranged between adjacent rows of guide blades serve, in particular, as cover elements which prevent the inner housing 16 in the guide blade carrier or other housing installation parts from thermal overstress protect by the turbine 6 flowing through hot working medium M.

The combustion chamber 4 is configured in the exemplary embodiment as a so-called annular combustion chamber, in which a plurality of burners 10 arranged around the turbine rotor 8 in the circumferential direction open into a common combustion chamber space. For this purpose, the combustion chamber 4 is configured in its entirety as an annular structure, which is positioned around the turbine rotor 8 around.

FIG. 2 shows in each case a section through a sealing plate 30, a securing bolt 32, a closure piece 34, a locking plate 36 and through the outer periphery of a mounted on the turbine rotor 8 turbine disk 38 a blade stage of the turbine unit 6th

The turbine disk 38 includes a blade retention groove 40 in which the blade 12 (not shown) is disposed. Through the cooling air hole 42 1 cooling air is supplied during operation of the gas turbine, which cools the turbine disk 36 and is also forwarded to the blade 12, not shown.

In order to prevent leakage of cooling air from the interior of the turbine disk 38 and penetration of hot working fluid M on the other hand, the sealing plate 30 is set on the side surface of the turbine disk 38. In this case, circulating cams 44, 46 circulating in the turbine disk 38 serve as spacers. The sealing plate 30 is tilted by an applied thereto, extending in the azimuthal direction edge 47 by means of the closure piece 34 on the turbine disk 38 and fixed radially and azimuthally with the locking pin 32 in a bore 48 of the turbine disk 38. The locking plate 36 prevents an axial pushing out of the securing bolt 32. The edge 47 is set back relative to an inner edge of the sealing plate 30.

The sealing plate 30 includes an attached, substantially in the axial and azimuthal direction extending sealing vanes 50 which seals the gap between the turbine disk 38 and adjacent vanes 14 against ingress of hot working fluid M from the turbine. Furthermore, the sealing plate 30 also provides for axial fixation of the blade 12 in the Schaufelfußnut 40 and secures them against displacement.

The FIG. 3 shows the sealing plate 30 in the top view. Notches 52 are introduced into the sealing plate 30 at a uniform spacing on the side facing the turbine rotor 8, which serve to receive the securing bolts 32. As a result, the sealing plate 30, which is larger due to the overall smaller number of sealing plates, is fixed along the entire circumference. Furthermore, the edge 47 can be seen for fixing the closure pieces 34.

The sealing plate 30 is in FIG. 4 shown in the inclined profile. In the side surface of the sealing plate 30, which rests in the mounted state on a further sealing plate 30, a slot 54 is introduced, in which a not shown corrugated sheet is introduced, so that the parting line lying between the sealing plates 30 is sealed and thus sealed.

The FIG. 5 again shows the sealing plate 30 in the plan. In this case, the notch 52 respectively introduced recess 56 is shown here, which interrupts the edge 47. It is adapted in its geometry to the size of the closure pieces 34, so that it is suitable for insertion of the closure piece 34 shown in more detail in the following figures. During assembly, closure pieces 34 can be lowered through the recess 56 and subsequently pushed along the edge 47 into its end position. Thus, a fixation of the already mounted sealing plate 30 is achieved on the turbine disk 38 and a good seal of the remaining gap.

The FIG. 6 shows the closure piece 34 in section. In the closure piece 34, a bore 58 is introduced, in which the securing bolt 32 is introduced. In the FIG. 7 , which shows the closure piece 34 in profile, in addition, a recess 60 is shown, which serves to receive the locking plate 36, which prevents axial displacement of the securing bolt 32. The FIG. 8 shows the closure piece again in the supervision. Clearly, the adaptation to the shape of the in the FIG. 5 Recognize recess 56 shown.

The FIG. 9 to FIG. 14 show the assembly process of the sealing plate 30 on the turbine disk 36. The sealing plate 30 is first lowered radially into the turbine disk groove 62 ( FIG. 10 . FIG. 11 ), then moved axially towards the blade 12 ( FIG. 12 ) and finally lifted radially ( FIG. 13 ). The shoulder 64 at the inner radius of the sealing plate 30 thus abuts against the cam 46 of the turbine disk 38. The closure piece 34 is inserted radially over the recess 56 on the sealing plate 30 in the groove 62 and circumferentially along the edge 47 shifted so far that its bore 58 is aligned with a bore 48 in the turbine disk 38 and a notch 52 in the sealing plate 52. There, the closure piece 34 is fixed with a locking bolt 32.

Subsequently, the other closure pieces 34 are used in the same way. Thus, the sealing plate 30 is secured radially and axially. Furthermore, the closure pieces 47 are in the assembled state to each other, so that a complete seal of the gap between the sealing plate 30 and side wall of the turbine disk groove 62 is ensured.

In the recess 60 of the closure piece 34, the locking plate 36 is inserted radially, which also has a bore in the center. In this and the holes 48, 58 of the safety pin 32 is inserted. This secures the radial Locking plate 36 and in the circumferential direction, the closure piece 34 and the sealing plate 30. Against axial pushing out of the securing bolt 32, the end of the locking plate 36 is bent radially downwards. The final assembly is in FIG. 14 shown.

The illustrated sealing plate 30 is substantially semicircular. Thus, the sealing plate 30 can be made in the turning process as a circular ring and then shared. As a result, a particularly simple construction of the gas turbine 1 is possible. Furthermore, a much better seal against cooling air loss is possible due to the smaller number of leakage surfaces compared to the previous scale-like arrangement.

Claims (7)

1. Turbine rotor (8),
   having a number of rotor blades (12) which are combined in each case to form rotor blade rows and are arranged on in each case one turbine disk (38),
   the respective turbine disk (38) having, on its side faces, a number of sealing plates (30) in the shape of circularly annular sections which are inserted into an azimuthally extending turbine disk groove (62),
   the respective sealing plate (30) having, on the side which faces the turbine axle, an azimuthally extending edge (47) which is spaced apart from the inner edge of the respective sealing plate (30),
   closure pieces (34) being arranged between the edge (47) of the respective sealing plate (30) and a side wall of the turbine disk groove (62),
   the edge (47) extending over the entire azimuthal length of the sealing plate and the closure pieces (34) bearing against one another in the azimuthal direction for sealing purposes,
   the respective sealing plate (30) comprising at least one recess (56) which extends substantially azimuthally on the side which faces the turbine axle, interrupts the respective edge (47) and is designed geometrically in such a way that the closure pieces (34) can be inserted into the turbine disk groove (62) through said recess (56).
2. Turbine rotor (8) according to Claim 1, in which two sealing plates (30) are provided per side face.
3. Turbine rotor (8) according to either of Claims 1 and 2, in which a slot (54) is made in those faces of two sealing plates (30) which face one another in each case, a metal sheet which connects the slots (54) which lie opposite one another in each case being inserted to seal the intermediate space between the faces.
4. Turbine rotor (8) according to one of Claims 1 to 3, in which the respective sealing plate (30) has a sealing vane (50) which extends substantially azimuthally and axially.
5. Turbine rotor (8) according to one of Claims 1 to 4, in which the respective closure piece (34) has a hole (58), the respective sealing plate (30) has a number of notches (52), and the side wall which delimits the turbine disk groove (62) has a hole (48) for receiving a securing pin (32).
6. Turbine rotor (8) according to one of Claims 1 to 5, in which the respective sealing plate (30) is produced by turning.
7. Gas or steam turbine system having a turbine rotor (8) according to one of Claims 1 to 6.

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