EP2379846A1

EP2379846A1 - Guide vane system for a turbomachine having segmented guide vane carriers

Info

Publication number: EP2379846A1
Application number: EP10700394A
Authority: EP
Inventors: Fathi Ahmad; Giuseppe Gaio; Holger Grote; Christian Lerner; Mirko Milazar; Mathias Stutt; Thomas-Dieter Tenrahm; Bernd Vonnemann
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2009-01-21
Filing date: 2010-01-05
Publication date: 2011-10-26
Anticipated expiration: 2030-01-05
Also published as: US9238976B2; CN102282340B; EP2379846B1; EP2211023A1; JP5357270B2; WO2010084028A1; CN102282340A; US20120039716A1; JP2012515869A

Abstract

A turbine guide vane system (1), in particular for a gas turbine (101), having a number of guide vane row and a guide vane carrier (1), is to enable particularly simple replacement of guide vanes, while maintaining a particularly high degree of efficiency, and thus designed for particularly short repair durations. For this purpose, the guide vane carrier (1) has a number of segments (24, 26), wherein a segment (24, 26) extends over the entire radial extension of the guide vane carrier (1) and the connection of the remaining segments (26) can be detached, and wherein the turbine guide vane carrier (1) has at least two sections (23, 25) along the axial extension thereof that are connected to one another and have a different number of segments (24, 26).

Description

description

The invention relates to a turbine guide vane carrier, in particular for a stationary gas turbine.

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 shaft. 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 under 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 shaft, a number of rotor blades, which are usually combined into blade groups or rows of blades, are arranged thereon and drive the turbine shaft via a momentum transfer from the working medium. For flow guidance of the working medium are also usually connected between adjacent rows of blades with the turbine housing, too

Guide vanes combined vanes arranged. These are attached via a blade root to a usually hollow cylindrical or hollow cone-shaped guide blade carrier and fastened on its side facing the turbine axis via a blade head on a common inner ring of the respective guide blade row. In stationary gas turbines, this often consists of an upper and a lower half, which are connected to each other via flanges.

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 degree of efficiency can basically be achieved for thermodynamic reasons. borrowed by an increase in the outlet temperature, with which the working medium flows from the combustion chamber and into the turbine unit. In this case, temperatures of about 1,200 ⁰ C to 1,500 ⁰ C are sought for such gas turbines and also achieved.

However, such high temperatures of the working medium are well above the melting temperature of the component materials used, for example, in the outflow region of the combustion chamber, so that the critical components for ensuring the required function of the gas turbine must be cooled strongly and protected with complex coating systems. In some cases, it can not be ruled out that, despite the use of these highly developed and proven technologies for the cooling and coating of the blades, premature replacement of guide vanes is necessary since the vane function is unduly impaired, for example, by partial loss of the coating or closure of cooling air bores. In the case of large stationary gas turbines, such an exchange measure can take at most several days, but on average approx. Two weeks, thereby causing an unintentional and expensive interruption of the operation of the gas turbine or of a gas and steam turbine power plant in which the gas turbine is used becomes.

The invention is therefore based on the object of specifying a turbine guide vane carrier, in particular for a gas turbine, which, while maintaining a particularly high efficiency, enables a particularly simple exchange of individual vanes and is therefore designed for a particularly short repair duration.

This object is achieved by the turbine vane carrier is designed according to the features of claim 1. The invention is based on the consideration that a shortened repair time would be possible by a particularly simple interchangeability of the vanes, if their assembly and disassembly could be simplified. At present, due to the structural conditions in modern stationary annular combustion chamber machines, the turbine must be uncovered in order to allow the access of the guide vanes. In this case, the guide vanes are within the guide vane carrier, which consists of an upper and a lower solid casting in stationary gas turbines, and thus also has to be disassembled to replace the vanes. In order to avoid this uncovering and lifting of the upper cast part of the guide blade carrier, the guide blade carrier should therefore be segmented in many sections in at least one section. By using more than two segments in this section, they are smaller than the remaining segments. This makes it possible to reach only by lifting individual segments of the area surrounded by it. In order to ensure accessibility of the guide vanes, a segment should cover the entire process

Radial expansion of the vane support extend and the connection of the respective segment with the rest of the vane carrier be solvable. Thus, for repair or replacement of a single vane of the first turbine stage, it is no longer necessary to have the upper casting of the first turbine stage

Leitschaufelträgers are lifted, but it is only the connection of the respective segment with the remaining portion of the vane support and with circumferentially adjacent segments solved, whereby - as the relevant segment over the entire

Radial expansion of the guide blade carrier extends - after removal of the respective segment, a direct reaching the radially further inwardly arranged vanes and their replacement is possible.

The highest temperatures in the gas turbine are at the outlet of the combustion chamber. Thus, the vane of the first turbine stage, ie the vane, which is the combustor chamber is closest to these highest temperatures and subject to the greatest wear. Accordingly, premature replacement as a result of damage caused by clogging of the cooling air bores (eg by inwardly oxidizing cooling air bores) is to be expected in particular in the case of this turbine guide vane. In order to simplify the exchange of individual ones of these vanes, the vane support should therefore advantageously be segmented multiple times in the section of the vane row closest to a combustion chamber of the gas turbine. In other words, the upstream side portion of the turbine vane carrier should have more segments than the remaining portion of the turbine vane carrier.

In order to achieve accessibility of all vanes of a row of vanes, so many segments should be provided that each segment can be handled by one, in the worst case by two technicians. Thus, an exchange of vanes can take place in each circumferential section by merely removing the respective segment radially outside the relevant guide vane. The exact geometric design of the segmentation should be adapted in a meaningful way to the handling of the machine.

In a further advantageous embodiment, the respective connection between axially adjacent segments is a screw connection and / or a tongue and groove connection. By screwing a particularly simple releasable connection of segments with each other and / or with the rest of the vane carrier is possible. Due to the circular arrangement of the segments around the entire circumference, however, a hooking in the manner of a tongue and groove connection is possible, in which the individual segments are bolted only to each other and are merely hooked to the rest of the guide blade carrier. In this way, a particularly simple disassembly and assembly of the individual segments is possible. In order to further simplify the dismantling of the guide vanes which can now be achieved by the segmentation of the guide blade carrier, the guide blade fixation of a gas turbine should be provided in a meaningful manner such that undisturbed disassembly of an arbitrarily circumferentially located segment is ensured, so that, depending on the Position of the blade to be replaced only the affected, radially further outwardly disposed segment must be dismantled. For this purpose, in an advantageous embodiment, the guide vane of the respective vane row with one of the segments of the remaining portion releasably connected. Thereby, after removal of the affected segment, the vane can be disassembled by releasing the connection with the segment of the section. The segments arranged in the inflow-side section thus do not serve for fastening guide vanes, but only for producing or maintaining the integrity of the gas turbine and possibly for separating spaces for cooling air with different pressures and / or temperatures.

In order to enable a simple disassembly of the guide vane in a gas turbine not only on the blade root side, but also on the blade head side of the respective vane, the vane of the respective vane row is advantageously facing at its the turbine axis

Side releasably connected to an inner ring in the radial direction. Thus, a radial distance of the vane is possible. This allows a particularly simple exchange.

A particularly simple replacement of the guide vane is possible by the fixation of the guide vane on the inner ring is designed as a simple connector. For this purpose, the respective vane advantageously comprises a spring which can be inserted in the radial direction into a groove of the inner ring. As a result, to replace the respective vane, the blade-side connection of the vane to the rest of the vane carrier can be easily released and the respective vane simply by loosening the connector in radial direction can be pulled out of the turbine. It is ensured by the blade-side fixation of the vane on the vane support during operation, a sufficient assurance.

In the previous design, the guide vanes of a row of guide vanes were fixed to the inner ring via a connection secured with pins, so that the entire inner ring had to be removed for removal and subsequently the guide vanes could be removed. In a releasable connection, for example in the manner of a simple plug connection of the guide vanes with the inner ring, therefore, the inner ring with the Brennkammernabe, d. H. a component connected to the combustion chamber and thus to the static part of the gas turbine. For this purpose, the inner ring is advantageously connected to a combustion chamber hub. This can be done for example by a fixation by welding, clamping o. Ä. When redesigning a gas turbine, the inner ring can also be manufactured directly as part of the combustion chamber hub.

Between the individual guide vanes, grooves are provided both on the blade root and on the blade head in the previous design, in which sealing plates are arranged between the guide vanes in the circumferential direction. However, if the vanes are to be removed individually, however, the sealing plates located in the grooves of the vane foot and the vane head block the vanes and may thus possibly prevent disassembly. Therefore, the fixation of the sealing sheets should be changed so that their removal is possible and thus a removal of individual vanes is simplified. For this purpose, at the sides of the blade root and / or blade head which are respectively facing the adjacent guide blade, bevels are advantageously used, in which bends are fixed by means of a tensioning element. Before the removal of the guide vanes thus the clamping element can be solved and the sealing plate can be removed, so that a particularly simple disassembly of the vane is possible.

In an advantageous embodiment, such a turbine guide vane carrier is used in a gas turbine. In order to allow a particularly easy accessibility of the guide vane for the exchange of individual guide vanes, an outer housing of the gas turbine advantageously comprises a manhole through which easy access to the segments of the vane support for the installation personnel is possible.

Advantageously, a gas and steam turbine power plant comprises such a gas turbine.

The advantages achieved by the invention are in particular that by the different segmentation of the vane support in the inflow-side section and in at least one remaining section those vanes, which are encompassed by inflow-side segments and are supported by the remaining portion, after removing a respective inflow-side segment are detachable from the rest of the vane carrier. Thus, a particularly simple replacement of vanes of a row of vanes is possible, since not the outer casing of the turbine and the upper half of the casting of the turbine nozzle carrier must be lifted in such an exchange from the rest of the gas turbine. The mechanics performing the replacement of the vanes can thus replace the vanes in the gas turbine with the outer casing closed, which can considerably reduce the effort required to replace the vanes and significantly reduce the required breast-feeding time of the gas turbine. Such a simplified replacement, in particular the first vane stage directly after the combustion chamber also allows an increase in the outlet temperature in conjunction with an increase in the efficiency of the gas turbine, since the simplified exchange option of the vanes on their durability less consideration must be taken. there In operation, variable exchange concepts are conceivable. Furthermore, such a construction, due to the simplified exchange in research and development, enables a comparatively faster test of new prototypes of Leitschau fine, for example, with novel coatings or new cooling concepts.

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

1 shows a guide blade system with hooked segments in longitudinal section,

2 a guide blade system with screwed segments in longitudinal section,

3 shows a cross section through the segments perpendicular to the turbine axis,

4 shows a combustion chamber hub of an annular combustion chamber,

5 shows the blade head side fixing of the guide vane according to the prior art

6 shows the blade head-side fixing of the guide blade with a plug connection,

7 shows a combustion chamber hub with the inner ring as a component,

8 shows a cross section through two adjacent guide vanes perpendicular to the turbine axis with grooves fixed in sealing elements according to the prior art,

9 shows a section through two adjacent vanes perpendicular to the turbine axis with clamping elements fixed sealing elements, and 10 shows a half section through a gas turbine.

The same components are provided in all figures with the same reference numerals.

FIG. 1 shows a turbine guide vane carrier 1, also referred to as a vane carrier, in sections in the region of the first two vane rows following in the hot gas direction onto a combustion chamber 2. In this case, the illustration shows a half section through the upper half 4 of a conically shaped guide blade carrier as well as the guide vanes 6 of the first turbine stage and guide vanes 8 of the second turbine stage arranged in each case in the vertex of the guide vane ring.

The vanes 6, 8 each comprise a blade root 10, 12 and a blade head 14, 16, via which their attachment to the other components takes place. The guide vanes 6, 8 of the first and second turbine stages are fastened to the guide blade carrier 1 with their blade roots 10, 12 and fixed to inner rings 18, 20 at their respective blade heads 14, 16. Here, both the inner ring 20 and the vane support 1 include a plurality of cooling systems 22, which provide a cooling air supply to the vane support 1, the vanes 6, 8 and the inner ring 22 to sufficiently cool these components due to the high hot gas temperatures.

The highest temperatures occur at the outlet of the combustion chamber 2, which is why the vanes 6 of the first row of vanes are exposed to the highest temperatures. As a result, despite all cooling measures, damage to the guide vanes 6 and thus an early replacement of these guide vanes 6 that is required can not be ruled out. In order to enable a particularly simple replacement of the guide vanes 6, the guide vane carrier 1 is segmented in many cases in the region of the first vane row. The guide blade carrier 1 comprises a number (in this case 12 pieces, see FIG. 3) of segments 24 in an inflow-side portion 23 and a guide-blade carrier 1 segmented in only one half 25 in a remaining portion 25. All segments 24, 26 are detachably connected to one another. In FIG. 1, the connection between the segments 24 of the inflow-side section 23 and the segments 26 of the remaining section 25 takes place via an interlocking by means of grooves 28 and springs 30 introduced into the segments 24 and the segments 26. A similar connection of the segments 24 is also provided provided with the combustion chamber wall 32 to separate a radially outer space from the guide vanes 6 and to allow for the stability and strength of the gas turbine required connection between the combustion chamber 2 and other segments 26.

The rest of the vane carrier is understood to be an upper and a lower half of a ring-shaped vane carrier which is annular in cross-section, as is already known in stationary gas turbines. In this case, two

Segments 26 provided in the remaining portion 25 of the vane support 1. In this respect, sections are always more segments 24 provided for the scope than other segments 26th

By entanglement, the connection of the respective segments 24 can be solved with the remaining segment 26 and the segment 24 can be removed radially. Thus, the vanes 6 of the first turbine stage can be reached without completely revealing the entire turbine from the outside. The vane 6 of the first turbine stage is releasably secured via the blade root 10 by means of a fastening device 34 on the remaining segment 26. After removal of the segment 24, this connection can be solved and the vane 6 is radially removable. The blade head 14 of the guide vane 6 of the first turbine stage in this case comprises a spring 36 which is inserted in a groove 38 of the inner ring 18. The attachment to the inner ring 18 is thus only a plug connection designed so that the guide vane 6 is easy to remove after loosening the fastening device 34 to the outside.

FIG. 2 likewise shows the guide blade system 1 as in FIG. 1, but here the detachable connection of the segment 24 to the remaining segment 26 is realized by means of a screw 40. The entanglement of the segment 24 with the combustion chamber wall 32 via grooves 28 and springs 30 is unchanged. Such a connection with a screw 40 may be desirable depending on the strength or geometric requirements in the guide vane 1.

3 shows a section perpendicular to the turbine axis through the guide vane carrier 1 at the level of the segments 24. In the example shown, a total of twelve segments 24 are provided, which are connected via flanges 52, for example with a screw connection. As a result, a secure hold of the multi-segmented portion 23 of the vane support 1 is ensured, even if the individual segments 24 are connected only via an entanglement with the rest of the segment 26 as shown in FIG. The segmentation can also be done in other ways and adapted to the handling of the machine.

4 shows the combustion chamber hub 54 of a gas turbine. This comprises a groove 56 into which the inner ring 18 shown in FIGS. 1 and 2 is inserted. Furthermore, a groove 58 is provided, in which a sealing plate for sealing the gap between the blade root 14 of the guide vane 6 of the first turbine nenstufe and the combustion chamber hub 54 is provided.

5 shows a known attachment of the guide blade root 14 to the combustion chamber hub 54 of the gas turbine in detail. In this case, the blade root 14 comprises a spring 36 which is inserted into a groove 38 of the inner ring 18. There, the guide vane of the first turbine stage 6 is fixed by means of a pin 60. The inner ring 18 is then inserted into the groove 56 of the combustion chamber hub 54. At the same time, the blade root 14 a groove 62 for receiving a sealing plate 64, which is also located in the groove 58 of the combustion chamber hub 54.

Since the pin 60 is parallel to the turbine axis, a complete removal of the inner ring 18 is required for disassembly of the guide vane 6 of the first turbine stage so far. Only after the removal of the pin 60 can be removed and the vane 6 removed. Therefore, the connection of the vane 6 to the combustion chamber hub 54 is now more as shown in FIG. 6:

The spring 36 of the blade root 14 is no longer connected via a pin to the inner ring 18 in the groove 38, but is merely stuck to the inner ring 18. Instead, the inner ring 18 is fastened to the combustion chamber 54 by means of a pin 66 or a screw. As a result, the guide vanes 6 can also be removed individually, without disassembling the inner ring 18. A secure hold of the vanes 6 is still on the mounting device 34, as shown in Figures 1 and 2, ensured.

In such an embodiment, it is also possible to manufacture the inner ring 18 directly as part of the combustion chamber hub 54. As a result, no separate parts are required lent. Such a configuration is shown in FIG.

8 shows a section perpendicular to the turbine axis through two adjacent vanes 6 of the first turbine stage, as is common in the prior art. In this case, grooves 68 are introduced into the blade feet 10 and blade heads 14 on the surface facing the adjacent guide blade 6, into which sealing plates 70 are inserted, which close the gaps between the blade roots 10 or blade heads 14. However, these sealing plates 70 can be a hindrance in the case of radical removal of individual guide vanes 6.

Accordingly, a plurality of guide vanes 6 are first to be unlocked and displaced in the circumferential direction, so that a guide Schaufei 6 comes out of engagement of the sealing plates 70 and can be expanded radially.

To avoid this, as shown in FIG. 9, the grooves 68 are replaced by bends 72. The sealing plates 70 are now inserted into the folds 72 and secured by clamping elements 74 there. To remove a single guide vane 6, the clamping element 74 can now be released and the sealing element 70 removed. Then, the guide vane 6 can be removed radially. Thus, an exchange of individual vanes is greatly facilitated.

Such a guide blade system 1 described here is advantageously used in a gas turbine 101.

A gas turbine 101, as shown in FIG. 10, has a compressor 102 for combustion air, a combustion chamber 2 and a turbine unit 106 for driving the compressor 102 and a generator or a working machine (not shown). For this purpose, the turbine unit 106 and the compressor 102 are arranged on a common turbine shaft 108, 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 turbine axis 109. The running in the manner of an annular combustion chamber 2 is equipped with a number of burners 110 for the combustion of a liquid or gaseous fuel.

The turbine unit 106 has a number of rotatable blades 112 connected to the turbine shaft 108. The blades 112 are annularly disposed on the turbine shaft 108 and thus form a number of blade rows. Furthermore, the turbine unit 106 includes a number of stationary vanes 6, 8, 114, which are also attached in a donut-like manner to a vane support 1 of the turbine unit 106 to form rows of vanes. The blades 112 serve to drive the turbine shaft 108 by momentum transfer from the turbine unit 106 flowing through the working medium M. The vanes 6, 8, 114, 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 114 or a row of guide vanes and of a ring of rotor blades 112 or a row of revolutions is also referred to as a turbine stage.

Each vane 114 has a blade root 118, which is arranged to fix the respective vane 114 on a vane support 1 of the turbine unit 106 as a wall element. Each rotor blade 112 is fastened to the turbine shaft 108 in a similar manner via a blade root 119.

Between the spaced-apart platforms 118 of the guide vanes 114 of two adjacent rows of guide vanes, a respective ring segment 121 is arranged on the guide blade carrier 1 of the turbine unit 106. The outer surface of each ring segment 121 is spaced apart in the radial direction from the outer end of the blades 112 lying opposite it by a gap. The between adjacent

Leitschaufelreihen arranged ring segments 121 serve in particular as cover that protect the inner housing in the guide blade carrier 1 or other housing-mounting components from thermal overload by the turbine 106 flowing through the hot working medium M.

The combustion chamber 2 is configured in the exemplary embodiment as a so-called annular combustion chamber, in which a plurality of burners 110 arranged around the turbine shaft 108 in the circumferential direction open into a common combustion chamber space. For this purpose, the combustion chamber 2 is configured in its entirety as an annular structure, which is positioned around the turbine shaft 108 around. By using a turbine guide vane carrier 1 of the abovementioned embodiment in such a gas turbine 101, a significantly simplified repair can be achieved by a considerably simpler interchangeability of individual guide vanes 6, in particular the first turbine stage, with high efficiency of the gas turbine 101.

Claims

claims

A turbine vane support (1), in particular for a stationary gas turbine (101), comprising a number of segments (24, 26), wherein a segment (24) extends over the entire radial extent of the turbine vane support (1) and the connection of the respective segment (24) is releasable with adjacent segments (24, 26), characterized in that the turbine vane support (1) along its axial extent at least two interconnected portions (23, 25) having a different number of segments (24, 26) ,

A turbine vane support (1) according to claim 1, which has an inflow-side section (23) and at least one remaining section (25), wherein the inflow-side section (23) has a larger number of segments (24) than the at least one remaining section (FIG. 25).

3. Turbine vane support (1) according to claim 1 or 2, wherein the connection between axially adjacent segments

(24, 26) is a screw connection and / or a tongue and groove connection.

4. Turbine guide vane carrier (1) according to one of claims 2 to 3, wherein the at least one remaining portion (25) at its the inflow-side portion (23) facing side has a radially inwardly projecting projection, such that this in the radial direction of the Segments (24) of the inflow-side portion (23) is encompassed.

A gas turbine engine having a turbine vane support (1) according to any one of claims 1 to 4, comprising a series of vanes (6) releasably secured to the segments (26) of the at least one remaining section (25).

6. Gas turbine according to claim 5 with a turbine guide carrier according to claim 4, wherein the guide vanes (6) are fixed to the projection.

7. Gas turbine according to claim 5 or 6, wherein a guide vane (6) of the respective vane row on its the turbine axis (109) facing side with an inner ring (20) is detachably connected.

8. Gas turbine according to claim 7, wherein the respective guide vane (6) comprises a spring (36), which in the radial direction in a groove (38) of the inner ring (20) can be inserted.

9. Gas turbine according to one of claim 7 or 8, wherein the inner ring (18) with a combustion chamber hub (54) is connected.

10. Gas turbine according to one of claims 5 to 9, wherein the in the inflow-side portion (23) provided for segments (24) are connected to a combustion chamber wall (32).

11. Gas turbine according to one of claims 5 to 10, wherein between adjacent guide vanes (6) of the respective row of vanes, a sealing plate (70) is provided, wherein on the adjacent vane (6) facing sides of the blade root (10) and / or Blade head (14) are introduced bends (72) in which the sealing plate (70) by means of a clamping element (74) is fixed.

12. Gas turbine (101) according to any one of claims 5 to 11, wherein in an outer housing of the gas turbine (101) is introduced a manhole.