EP3256783B1 - Hot gas-conducting casing - Google Patents

Description

The present invention relates to a hot gas-carrying housing comprising a hot gas duct having an annular cross-section, wherein the hot gas duct is bounded inside by a housing inner wall and externally by a housing outer wall provided with at least one hot gas inlet opening is closed at its one end by a housing end wall connecting the housing inner wall and the housing outer wall together and on its other end face has an annular Heißgasauslassöffnung, projecting from the housing inner wall, an annular fastening web radially inwardly. Furthermore, the present invention relates to a gas turbine plant comprising a gas turbine housing accommodating a compressor and a turbine, a shaft passing through the gas turbine housing and interconnecting the compressor and the turbine, and at least one combustion chamber located outside the gas turbine housing and via a hot gas carrying housing disposed in the gas turbine housing mentioned type fluidly connected to the gas turbine housing, wherein the shaft is enclosed by the housing inner wall of the hot gas-carrying housing and between the housing inner wall and the shaft is a hollow cylindrical shaft protection jacket having an outwardly projecting and provided with a fastening web of the hot gas-carrying housing receiving circumferential groove annular shoulder, which is spaced by a predetermined amount in the radial direction of the housing inner wall of the hot gas-carrying housing.

Gas turbine plants with hot gas-carrying housings of the type mentioned are in the prior art, for example from the EP 1 170 464 A2 , already known. They usually include a gas turbine housing in which a compressor and a turbine are accommodated, wherein the compressor and turbine are interconnected by a shaft. Furthermore, a plurality of combustion chambers are provided, for example arranged in the form of Silobrennkammern on both sides of the gas turbine housing and are fluidically connected via an inserted into the gas turbine housing hot gas-carrying housing with the interior of the gas turbine housing. The hot gas-carrying housing comprises a hot gas channel having an annular cross section, which is bounded on the inside by a housing inner wall and on the outside by a housing outer wall which is provided with a plurality of hot gas inlet openings, the number of which normally corresponds to the number of combustion chambers. At its one end face of the hot gas channel is closed by a housing inner wall and the housing outer wall interconnecting housing end wall, and at its other end face, the hot gas channel to an annular Heißgasauslassöffnung, as there hot gas leading housing is disposed within the gas turbine housing such that the housing end wall to the compressor and the Hot gas outlet opening points in the direction of the turbine. Laying down the hot gas-carrying housing within the turbine housing is an annular mounting web radially inwardly from the housing inner wall, which engages in a circumferential groove of a ring heel of a hollow cylindrical wave protection jacket, which is disposed between the housing inner wall of the hot gas-conducting housing and the shaft, of the housing inner wall of the hot gas-carrying housing is enclosed.

During operation of the gas turbine plant, a fuel-air mixture is burned in the combustion chambers, whereupon the hot and pressurized combustion exhaust gases are introduced from the combustion chambers via the hot gas-carrying housing in the gas turbine plant and guided to the turbine, in which they set the shaft in rotation , Here, the thermal energy of the combustion exhaust gases is converted into mechanical energy. The compressor provides the combustion air required for combustion. In addition, part of the compressed air emerging from the compressor is mostly used as cooling fluid for cooling thermally stressed components of the gas turbine plant. A Such thermally stressed component is, inter alia, the housing inner wall of the hot gas-carrying housing. This is cooled by passing compressed ambient air through a cooling channel, which is defined between the wave protective jacket and the housing inner wall of the hot gas-carrying housing.

A problem with the cooling of the housing inner wall of the hot gas-conducting housing is that in the transition region between the housing inner wall and the fastening web due to thermal stresses often cracks mainly in the housing inner wall arise that regularly involve extensive and expensive maintenance and repair work. The thermal stresses are due to large temperature differences between the fastening web and the inside of the housing inner wall, since the fastening web is arranged close to the cooling described above, while the inside of the housing inner wall is exposed to the very high temperatures of the combustion gases.

One known way of reducing cracking is to less cool the fastening web and reduce said temperature differences in this way. In this connection, it has been proposed to guide the cooling air through cooling air openings provided in the annular shoulder of the wave protection jacket radially inwardly of the fastening web. However, this approach has the consequence that the entire transition region between the housing inner wall and fastening web becomes very hot for lack of adequate cooling, which is why the service life of the transition region is only slightly improved.

Furthermore, it has been proposed to provide the fastening web itself with passage openings for the passage of cooling air, so that the cooling air is passed directly through the fastening web. In addition to this approach is in the EP 1 170 464 A2 proposed that slots for cooling air are performed in a radially outer, conical portion of the fastening web. In this way, a significant improvement in the batch load change number can be achieved. A disadvantage of such through holes in the fastening web consists however in an increased and variable cooling air consumption. In addition, this solution is accompanied by increased wear of the fastening web, since the fastening web has a significantly reduced contact surface.

Based on this prior art, it is an object of the present invention to provide a hot gas-carrying housing and a gas turbine plant of the type mentioned above with alternative construction.

To achieve this object, the present invention provides a hot gas-carrying housing of the type mentioned, which is characterized in that the fastening web is provided along its circumference with a plurality of the fastening web in the axial direction severing slots, each having at least a first slot portion, starting from extends outwardly from the free end of the fastening web. Such slots, which are preferably produced according to the invention by means of water jet cutting, act as relief cuts and compensate for thermally induced stresses in the transition region between the housing inner wall and the fastening web. Investigations have shown that the slot load change number can be improved many times thanks to the arrangement of such slots. If the slots are provided with a very small slot width, an additional variable cooling air consumption and a reduced wearing surface of the fastening web are also effectively avoided.

According to one embodiment of the present invention, the slots are arranged at uniform intervals from each other in the circumferential direction, in particular in pitches in the range of 4 ° to 10 °, preferably 5 °. With such divisions, a very good relief effect was achieved.

The first slot sections preferably extend at least partially in the radial direction, preferably completely in the radial direction.

The width of the first slot sections is advantageously in the range of 0.05 and 1.5 mm, in particular in the range of 0.1 to 0.5 mm.

According to one embodiment of the present invention, at least some of the slots, in particular all slots, have a second slot section which is connected to the first slot section and in particular intersects this slot. Such additional second slot sections can also have a positive effect on the Anglie load cycle number.

Preferably, the second slot portions extend at least partially in the circumferential direction.

Particularly preferably, at least some of the slots, in particular all slots are formed substantially T-shaped.

According to the present invention, curved slot end sections can be connected to the free ends of the second slot sections, which in particular are bent in a hook-like manner, the free ends of the slot end sections of a slot advantageously being substantially mutually facing each other. By such Schlitzendabschnitte can be reduced notch effects.

Preferably close to the free ends of the second slot sections recesses, in particular circular recesses. Such recesses also serve to reduce the notch effect.

The second slot sections and / or the slot end sections advantageously have a width of between 0.05 and 1.5 mm, in particular in the range of 0.1 to 0.5 mm.

According to a variant of the present invention, the fastening web is provided with a plurality of elongated passage openings, the number of which, in particular, the number of slots corresponds, wherein the passage openings preferably cross the slots, wherein crossing through openings and slots in particular form a T-shape. Such passage openings serve to guide a cooling fluid through the attachment web. In this variant, the fastening web is thus cooled directly.

The passage openings preferably extend substantially in the circumferential direction.

According to one embodiment of the present invention, the passage openings have a width in the range of 3 to 10 mm, in particular in the range of 4 to 6 mm.

The free end regions of the passage openings are advantageously rounded in order to reduce the notch effect, wherein the radially outer portions of the free end regions in particular each describe the shape of a parabola half. Investigations have shown that the provision of a parabola-shaped rounding in relation to the notch effect gives better results than, for example, an arched curve.

To achieve the object mentioned above, the present invention further provides a gas turbine plant with a compressor and a turbine receiving gas turbine housing, a gas turbine housing passing through the compressor and the turbine interconnecting shaft and at least one arranged outside of the gas turbine housing combustion chamber, via a in the Gas turbine housing arranged hot gas-carrying housing according to the present invention is fluidly connected to the gas turbine housing, wherein the shaft is enclosed by the housing inner wall of the hot gas-conducting housing and between the housing inner wall and the shaft a hollow cylindrical shaft protection jacket is arranged, which has an outwardly projecting and with a fastening web of the hot gas-conducting housing having receiving circumferential groove provided annular shoulder, which is spaced by a predetermined amount in the radial direction of the housing inner wall of the hot gas-carrying housing.

Preferably, a hollow cylindrical trained and provided with cooling air openings blast protective jacket is arranged between the shaft protection casing and the housing inner wall, which is fastened to the shaft protection casing. Such a protective radiation jacket serves to prevent a transfer of heat from the housing inner wall in the direction of the shaft. In addition, an impact air cooling of the housing inner wall of the hot gas-conducting housing is provided via the cooling air openings, which achieves a very effective cooling effect.

Advantageously, the jet shield is immediately adjacent to or directly attached to the annular shoulder. As a result, the impingement air cooling also cools the transition region between the housing inner wall of the housing carrying the hot gas and the fastening web projecting therefrom.

Figur 1

eine schematische perspektivische Ansicht einer Gasturbinenanlage gemäß einer Ausführungsform der vorliegenden Erfindung;

Figur 2

eine schematische perspektivische Ansicht eines heißgasführenden Gehäuses der in Figur 1 dargestellten Gasturbinenanlage;

Figur 3

eine perspektivische Teilansicht des in Figur 2 dargestellten heißgasführenden Gehäuses;

Figur 4

eine vergrößerte Querschnittansicht der in Figur 1 dargestellten Gasturbine in einem Bereich, in dem das in Figur 2 gezeigte heißgasführende Gehäuse an einem Wellenschutzmantel der Gasturbinenanlage festgelegt ist;

Figur 5

eine Vorderansicht einer ersten erfindungsgemäßen Ausführungsform eines Befestigungssteges des in Figur 2 dargestellten heißgasführenden Gehäuses;

Figur 6

eine Vorderansicht eines Befestigungssteges gemäß einer zweiten Ausführungsform der vorliegenden Erfindung;

Figur 7

eine Vorderansicht eines Befestigungssteges gemäß einer dritten Ausführungsform der vorliegenden Erfindung;

Figur 8

eine Vorderansicht eines Befestigungssteges gemäß einer vierten Ausführungsform der vorliegenden Erfindung;

Figur 9

eine Ansicht einer alternativen Ausgestaltung des in Figur 4 dargestellten Bereiches;

Figur 10

eine Vorderansicht eines Befestigungssteges gemäß einer fünften Ausführungsform der vorliegenden Erfindung; und

Figur 11

eine Vorderansicht eines Befestigungssteges gemäß einer sechsten Ausführungsform der vorliegenden Erfindung.

Further features and advantages of the present invention will become apparent from the following description of a gas turbine plant according to an embodiment of the present invention and different inventive hot air-carrying housing with reference to the accompanying drawings. That's it

FIG. 1

a schematic perspective view of a gas turbine plant according to an embodiment of the present invention;

FIG. 2

a schematic perspective view of a hot gas-carrying housing of in FIG. 1 shown gas turbine plant;

FIG. 3

a partial perspective view of the in FIG. 2 illustrated hot gas-carrying housing;

FIG. 4

an enlarged cross-sectional view of in FIG. 1 shown gas turbine in an area where the in FIG. 2 shown hot gas housing is fixed to a protective jacket of the gas turbine plant;

FIG. 5

a front view of a first embodiment according to the invention of a fastening web of the hot gas-carrying housing shown in Figure 2;

FIG. 6

a front view of a fastening web according to a second embodiment of the present invention;

FIG. 7

a front view of a fastening web according to a third embodiment of the present invention;

FIG. 8

a front view of a fastening web according to a fourth embodiment of the present invention;

FIG. 9

a view of an alternative embodiment of the in FIG. 4 represented area;

FIG. 10

a front view of a fastening web according to a fifth embodiment of the present invention; and

FIG. 11

a front view of a fastening web according to a sixth embodiment of the present invention.

The figures show a gas turbine plant 1 according to an embodiment of the present invention or components thereof. The gas turbine plant 1 comprises a gas turbine housing 2, which accommodates a compressor 3 and a turbine 4, which are connected to one another via a shaft 5. Further includes the gas turbine plant 1 two in FIG. 1 Not shown combustion chambers, which are arranged as Silobrennkammern side of the gas turbine housing 2 and connected via a corresponding piping 6 with a recorded in the gas turbine housing 2 hot gas-carrying housing 7 fluidly connected. The hot gas-carrying housing 7 comprises a hot gas channel 8 with a substantially annular cross-section. The hot gas channel 8 is bounded on the inside by a housing inner wall 9 and the outside by a housing outer wall 10, wherein on the housing outer wall 10, two hot gas inlet openings 11 are provided, which are fluidly connected to one of the piping 6 and thus to one of the combustion chambers. At its one end face of the hot gas channel 8 is closed by a housing inner wall 9 and the housing outer wall 10 interconnecting housing end wall 12, and at its other end an annular Heißgasauslassöffnung 13 is provided, the housing end wall 12 in the direction of the compressor 3 and the hot gas outlet 13 in the direction the turbine 4 has. From the housing inner wall 9 is adjacent to the hot gas outlet 13, a radially inwardly projecting annular attachment web 14 before. The fastening web 14 is provided along its circumference with a plurality of these slitting in the axial direction slots 15 which are arranged at equal intervals, wherein a pitch t in the present case is 5 °. The slots 15 are substantially T-shaped and include a radially extending first slot portion 16 which extends radially outwardly from the free end of the attachment web 14 and a second slot portion 17 connected to and intersecting the first slot portion 16 each circular recesses 18 connect to the free ends of the second slot portion 17. The first slot portions 16 and the second slot portions 17 of each slot 24 presently have a width B in the range of 0.1 to 0.5 mm and are made by water jet cutting. For manufacturing purposes, on the outside of the housing inner wall 9, starting from its free end, a circumferential recess 19 is formed, which makes it possible to To bring a water jet nozzle very close to the mounting bar 14.

The fastening web 14 is held in a circumferential groove 20 which is formed on a spaced by a predetermined amount in the radial direction of the housing inner wall 9 arranged annular shoulder 21 of a hollow cylindrical shaft protection jacket 22 which surrounds the shaft 5 in the region of the hot gas-carrying housing 7 and between the shaft 5 and the housing inner wall 9 of the hot gas-carrying housing 7 is arranged. Between the wave protection jacket 22 and the housing inner wall 9 extends a hollow cylindrical trained and provided with cooling air openings 23 jet protection jacket 24, which is also received in an annular recess 25 of the wave protection jacket 22. The annular recess 25 is according to FIG. 4 formed in a second radially outwardly from the shaft protection jacket 22 projecting second annular shoulder 26 which is spaced from the annular shoulder 21, to which the hot gas-carrying housing 7 is attached. Between the blast protective jacket 24 and the housing inner wall 9 of the hot gas-carrying housing 7, a first annular cooling air channel 27 is defined, through which during the normal operation of the gas turbine plant 1 cooling air is passed from the compressor 3 in the direction of the turbine 4. The cooling air passage 27 is continued by cooling air holes 28 which extend axially through the annular shoulder 21 and are formed radially inwardly of the circumferential groove 15. Another annular cooling air channel 29 is defined between the wave protection jacket 22 and the jet protection jacket 24 and fluidly connected via the cooling air openings 23 with the first cooling air channel 27.

During normal operation of the gas turbine plant 1, a fuel-air mixture is burned in the combustion chambers, wherein the combustion chambers are supplied by the compressor 3 with compressed ambient air. The hot and pressurized combustion gases generated in the combustion chambers are transmitted via the piping 6 and the hot gas inlet openings 11 introduced into the hot gas-carrying housing 7, then flow through the hot gas channel 8 and are introduced through the hot gas outlet 13 in the direction of the turbine 4 in the gas turbine housing 2. The thermally heavily loaded by the contact with the hot combustion gases housing inner wall 9 of the hot gas-carrying housing 7 is cooled by cooling air, which, while it flows through the first cooling air channel 27, absorbs heat from the housing inner wall 9 and, after receiving the annular shoulder 21 of the wave protection jacket 22nd trained cooling air holes 28 has happened, is discharged in the direction of the turbine 4. A supplementary cooling of the housing inner wall 9 is achieved by an impingement air cooling, which is caused by a cooling air flow, which is passed through the second cooling air channel 29 and directed through the cooling air openings 23 directly against areas of the housing inner wall 9.

In the transition region between the housing inner wall 9 of the hot gas-carrying housing 7 and the fastening web 14, large temperature differences occur because the housing inner wall 9 is exposed to substantially higher temperatures than the fastening web 14 due to the combustion gases. Thanks to the freedom of movement afforded by the fastening web 14 thanks to the slots 15, stresses caused by these temperature differences can be largely compensated, whereby the number of load cycles up to which cracking of the housing inner wall 9 occurs in the transition region is significantly increased , As a result, maintenance and repair intervals can be extended and costs can be reduced.

The FIGS. 6 to 8 show views of the mounting web 14 with alternatively formed slots.

The slots 30 according to FIG. 6 each comprise a first slot portion 31 and a second slot portion 32, the formation of which substantially corresponds to that of the slot portions 16 and 17 of the slots 15. To the free ones Ends of the second slot sections 32 are each followed by hook-shaped bent slot end sections 33, the free ends of which face each other substantially.

The slots 34 according to FIG. 7 comprise a first slot portion 35 which extends radially outwardly from the free end of the attachment web 14, a second slot portion 36 connected to and crossing the first slot portion 35, two hook-shaped transition slot portions 37 adjacent to the free ends of the second slot portion 36 and two third slot portions 38 which adjoin the transition slot portions 37 and extend substantially parallel to the first slot portion 35.

The slits 39 according to FIG. 8 comprise a first slot portion 40 which extends radially outwardly from the free end of the attachment web 14, a second slot portion 41 connected to and crossing the first slot portion 40, and slot end portions 42 adjacent and hook-like bent to the free ends of the second slot portion 41 Whose free ends are substantially facing each other, wherein the rounding or the radius of the Schlitzendabschnitte 42 substantially larger than that of in FIG. 6 shown Schlitzendabschnitte 33 is selected.

FIGS. 9 and 10 show an alternative embodiment of the invention in FIG. 4 shown area. Shown is the housing inner wall 9, which is provided adjacent to the Heißgasauslassöffnung with a radially inwardly projecting annular attachment web 43. The fastening web 43 is provided along its periphery with a plurality of these axially dividing slots 44 which extend radially outwardly from the free end of the fastening web 43 and are arranged at regular intervals at a predetermined pitch. Furthermore, the attachment web 43 is provided with a plurality of elongate passage openings 45, the number of which corresponds to the number of slots 44, wherein the through holes 45, the slots 44 intersect and form together with these substantially a T-shape. The width B of the slots 44 is present in the range of 0.1 to 0.5 mm, the width b of the through holes 45 in the range of 3 to 10 mm and the length l of the through holes 45 in the range of 20 to 40 mm. The free end portions of the through holes 45 are formed rounded, each rounding present describes the shape of a semicircle. The fastening web 43 is held in a circumferential groove 46, which is formed at a spaced by a predetermined amount in the radial direction of the housing inner wall 9 arranged annular shoulder 47 of a hollow cylindrical shaft protection jacket 48 which surrounds the shaft 5 in the region of the hot gas-carrying housing 7 and between the shaft 5 and the housing inner wall 9 of the hot gas-carrying housing 7 is arranged. Between the wave protection jacket 48 and the housing inner wall 9 extends a hollow cylindrical trained and provided with cooling air openings 49 jet protection jacket 50, which is also received in an annular recess 51 of the annular shoulder 47. Between the blast protective jacket 50 and the housing inner wall 9 of the hot gas-carrying housing 7, a first annular cooling air channel 52 is defined, through which cooling air is conducted from the compressor 3 in the direction of the turbine 4 during the normal operation of the gas turbine plant 1. The cooling air channel 52 is continued by the passage 45 provided on the attachment web 43 in the direction of the turbine 4. Another annular cooling air channel 53 is defined between the wave protection jacket 48 and the jet protection jacket 50 and fluidly connected via the cooling air openings 49 with the first cooling air channel 52.

In the FIG. 9 illustrated variant has the advantage over the variant shown in Figure 4, that the fastening web 43 is better cooled thanks to the formed thereon through holes 45. Furthermore, the impingement air cooling also acts in an area near the transition area Housing inner wall 9 and fastening web 43, since the blast protective jacket 50 is fixed directly on the annular shoulder 47.

FIG. 11 shows an alternative embodiment of formed on the mounting web 43 through holes 54. The through holes 54 differ from the in FIG. 10 represented passage openings 45, that the curves of the free end portions of the through holes 54 in the region of their radially outer portions each describe the shape of a parabolic half. Such rounding is advantageous in terms of reducing the notch effect.

Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims (18)

1. Hot gas-conducting casing (7) comprising a hot gas duct (8) of annular cross section, wherein the hot gas duct (8) is bounded on the inside by a casing inner wall (9) and on the outside by a casing outer wall (10) provided with at least one hot gas inlet opening (11), is closed at its one end by a casing end wall (12) connecting the casing inner wall (9) and the casing outer wall (10) with each other and at its other end has an annular hot gas outlet opening (13), wherein an annular attachment web (14; 43) projects radially inward from the casing inner wall (9), wherein the attachment web (14; 43) along its periphery is provided with a number of slots (15; 30; 34; 39; 44) passing through the attachment web (14; 43) in the axial direction, each of which has at least one first slot section (16; 31; 35; 40) extending outward proceeding from the free end of the attachment web (14; 43).
2. Casing (7) according to Claim 1, characterized in that the slots (15; 30; 34; 39; 44) are arranged at regular distances from each other, in particular in pitches (t) in the range of 4° to 10°, preferably 5°.
3. Casing (7) according to one of the preceding claims, characterized in that the first slot sections (16; 31; 35; 40) extend at least partially in radial direction.
4. Casing (7) according to one of the preceding claims, characterized in that the first slot sections (16; 31; 35; 40) have a width (B) between 0.05 and 1.5mm, in particular in the range of 0.1 to 0.5mm.
5. Casing (7) according to one of the preceding claims, characterized in that at least some of the slots (15; 30; 34; 39), in particular all slots, have a second slot section (17; 32; 36; 41) connected with the first slot section (16; 31; 35; 40), in particular crossing the same.
6. Casing (7) according to Claim 5, characterized in that the second slot sections (17; 32; 36; 41) extend at least partially in peripheral direction.
7. Casing (7) according to Claim 5 or 6, characterized in that at least some of the slots (15; 30; 34; 39), in particular all slots, are essentially T-shaped.
8. Casing (7) according to one of Claims 5 to 7, characterized in that the free ends of the second slot sections (32; 41) have slot end sections (33; 42) adjoined to them, which are bent, in particular bent in the shape of a hook.
9. Casing (7) according to Claim 8, characterized in that the free ends of the slot end sections (33; 42) of a slot (30; 39) point essentially towards each other.
10. Casing (7) according to one of Claims 5 to 7, characterized in that the free ends of the second slot sections (17) have recesses (18) adjoined to them, in particular circular recesses.
11. Casing (7) according to one of Claims 5 to 10, characterized in that the second slot sections (17; 32; 36; 41) and/or the slot end sections (33; 42) have a width between 0.05 and 1.5mm, in particular in the range of 0.1 to 0.5mm.
12. Casing (7) according to one of Claims 1 to 4, characterized in that the attachment web (43) is provided with several elongate through-openings (45; 54), the number of which corresponds in particular to the number of slots (44), wherein the through-openings (45; 54) preferably cross the slots (44), wherein through-openings (45; 54) and slots (44) crossing each other form a T-shape, in particular.
13. Casing (7) according to Claim 12, characterized in that the through-openings (45; 54) extend essentially in peripheral direction.
14. Casing according to Claim 12 or 13, characterized in that the through-openings (45; 54) have a width (b) in the range of 3 to 10mm, in particular in the range of 4 to 6mm.
15. Casing (7) according to one of Claims 12 to 14, characterized in that the free end regions of the through-openings (45; 54) are rounded, wherein the radially outwardly arranged sections of the free end regions, in particular, describe the shape of a semi-parabola, respectively.
16. Gas turbine plant (1) having a gas turbine casing (2) in which a compressor (3) and a turbine (4) are received, a shaft (5) passing through the gas turbine casing (2) and connecting the compressor (3) and the turbine (4) to each other and at least one combustion chamber arranged outside the gas turbine casing (2), which via a hot gas-conducting casing (7) arranged inside the gas turbine casing (2) according to one of the preceding claims, is flow-connected to the gas turbine casing (2), wherein the shaft (5) is surrounded by the casing inner wall (9) of the hot gas-conducting casing (7), and a hollow-cylindrical shaft protective casing (22; 48) is arranged between the casing inner wall (7) and the shaft (5), which protective casing comprises an outwardly projecting annular shoulder (21; 47) provided with a peripheral groove (20; 46) in which the attachment web (14; 43) of the hot gas-conducting casing (7) is received, the annular shoulder being spaced apart by a predetermined amount in radial direction from the casing inner wall (9) of the hot gas-conducting casing (7) .
17. Gas turbine plant (1) according to Claim 16, characterized in that a hollow-cylindrically shaped radiation protective casing (24; 50) provided with cooling air openings (23; 49) is arranged between the shaft protective casing (22; 48) and the casing inner wall (9), and is attached to the shaft protective casing (22; 48).
18. Gas turbine plant (1) according to Claim 17, characterized in that the radiation protective casing (50) is attached directly adjacent to or directly to the annular shoulder (47).

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