WO2014173568A1

WO2014173568A1 - Heat shield block for a heat shield of a combustion chamber

Info

Publication number: WO2014173568A1
Application number: PCT/EP2014/053939
Authority: WO
Inventors: Andreas Böttcher; Matthias CHLEBOWSKI; Andre Kluge; Stefan Reich; Daniel Vogtmann
Original assignee: Siemens Aktiengesellschaft
Priority date: 2013-04-22
Filing date: 2014-02-28
Publication date: 2014-10-30

Abstract

The invention relates to a heat shield block (30) for a heat shield (20, 22) of a gas turbine (1), which heat shield block can be detachably fastened to a supporting structure (24) by means of at least one retaining element (26, 28). The heat shield block has a cold side (32) facing the supporting structure (24), an opposite hot side (34), which can be exposed to a hot medium, and lateral surfaces (36), which connect the cold side (32) to the hot side (34). The heat shield block (30) comprises at least one engagement means (50), which has at least one retaining bar (46, 48), which has a contact surface (64) facing away from the cold side (32). The heat shield block makes it possible to fasten the heat shield block to the supporting structure in an especially secure manner. For this purpose, the engagement means is designed as a cavity (38) extending from the cold side, so that the cavity forms an interior arranged in the heat shield block, which interior is open toward the cold side and closed toward the lateral surfaces. The at least one contact surface (64) of the at least one retaining bar (46, 48) of the engagement means (50) is arranged inside the heat shield block (30) in the region of the interior.

Description

description

Heat shield block for a heat shield of a combustion chamber The invention relates to a stone shield heat shield block and a heat shield with at least one such heat ^¬. The invention also relates to a combustion chamber lined with such a heat shield and to a gas turbine.

In many technical applications, use of heat shields, which hot gases from 1000 to 1600 degrees resist Müs ^¬ sen. In particular, gas turbines, such as those used in power-generating power plants and aircraft engines, have correspondingly large shielded by heat shields

Areas inside the combustion chambers. Because of thermal expansion and large dimensions, the heat shield must be composed of a plurality of individual, generally ceramic heat shield bricks, spaced apart from each other with a sufficient gap to a support structure. This gap offers the heat shield bricks, which can also be called heat shield elements, sufficient space for thermal expansion. However, since the gap also allows direct contact of the hot combustion gases with the metallic support structure and the holding elements, cooling air can be injected as a countermeasure through the gaps in the direction of the combustion chamber.

A generic heat shield thus comprises a support structure and a number of heat shield bricks which are releasably secured to the support structure by means of retaining elements. Each of the heat shield bricks has one of the support structure ^¬ facing cold side and a cold side opposite, acted upon by a hot medium hot side. The cold side and the hot side are connected by side surfaces of the Hit ^¬ zeschildsteines. The generic heat shield can for the lining of a combustion chamber of a gas turbine be provided. In this case, the support structure extends on the inside of a combustion chamber wall of the combustion chamber.

At least one heat shield brick of the heat shield is designed such that it has at least one engagement device with at least one retaining bolt. The heat shield block is thereby attached to the support structure that at least one Pad facing away from a fastening section on the tag structure buildin ^¬-saturated holding member having a holding portion with at least one holding head on one of the cold side surface rests of a retaining bolt. The holding head of the holding ^¬ element can also be referred to with gripping portion. Ov ^¬ SHORT- engages the retaining element with a bias voltage to the retention tab so that the at least one holding head is pressed onto the supporting surface of the retaining key due to the restoring forces in the direction of the support structure and pulls the Hit ^¬ zeschildstein to the support structure. The heat shield brick can be fastened, for example, with four such retaining elements on the support structure. EP 1701095 Al discloses a mentioned ^heat shield of a combustion chamber of a gas turbine comprising a support structure and a number of detachably arranged on the supporting structure heat shield bricks. To protect the combustion chamber wall, the heat shield bricks are arranged across the surface, leaving expansion gaps on the support structure, wherein each heat shield brick has a cold-side facing the support structure and a hot side which is opposite to the cold side and can be charged with a hot medium. The heat shield ^¬ stones are resiliently secured to the support structure with four metal holding elements. For this purpose, each Halteele ^¬ ment comprises a holding section with a holding head (Greifab ^{¬ section} ) and a mounting portion. In each heat ^¬ shield stone retaining grooves are introduced on two opposite peripheral sides. A retaining bolt is thereby formed between the retaining groove and the cold side. The Halterie ^¬ gel comprises a remote from the cold side support surface, which is formed by a side surface of the retaining groove. To hold the heat shield stone, the gripping sections the retaining elements opposite eingrei ^¬ fen in the retaining grooves. The thus the heat shield block opposite buildin ^¬ saturated holding elements are guided with its fastening portion in a downstream of the heat shield block extending fastening confining groove in the support structure. For protection against hot gases, the gripping portions of the metallic holding elements are cooled. For this purpose, in the stone holder in the region of the holding ^¬ section and in the retainer bars the heat shield bricks Publ ^¬ voltages introduced, which are aligned with the support structure Toggle parent cooling air hole, so that cooling air from the cooling air hole flowing rebounds in a direct line to a cold side of the gripping portion ,

Despite this cooling of the gripping portions according to the prior art, it can when applying the heat shield with

Hot gas to hot gas in the area of the expansion gaps between the heat shield bricks come. This can lead to scaling of the holding elements and the support structure and in the worst case due to the damaged holder to a drop of heat shield stones from the support structure.

It is therefore an object of the present invention to admit an aforementioned heat shield brick, a heat shield with at least one such heat shield brick and a heat shield lined with the combustion chamber and a gas turbine ^¬ , with which a particularly secure attachment of the heat shield brick is made possible on the support structure.

The object is achieved in a heat shield block of the type mentioned above in that the A ^¬ handle device is designed as a cold side toward the opening recess. The at least one bearing surface of the at least one retaining bolt of the engagement device is arranged in the interior of the heat shield brick. The engagement device is thus a recess extending from the cold side and forming an interior space arranged in the heat shield block, which opens toward the cold side and is closed towards the side surfaces. The at least one The surface of the at least one retaining bolt of the engagement device is arranged in the interior of the heat shield brick in the region of the interior. Thus the attachment of at least ei ^¬ NEN retaining element to the heat shield stone is laid in the interior of the heat shield stone according to the invention. The at least one retaining element thus no longer engages, as in the prior art, in a retaining groove arranged in a side surface of the heat shield. Instead, the at least one engagement device is in each case designed as a recess opening toward the cold side, so that the retaining element is introduced from the support structure with its holding section through the opening of the recess located in the cold side into the engagement device and with at least one Holding head engages from the cold side behind a retaining bolt, so that the retaining head rests on one of the cold side abge ^¬ facing bearing surface of the retaining bolt and is located in this position inside the heat shield brick. Inside the heat shield block is to be understood that the holding head is arranged in the recess, ie in the interior formed by the recess. The bearing surface of the retaining bolt forms, for example, a side wall or a section of a side wall of the interior space. The retaining bolt is thus between the on the

Support surface lying holding head and the support structure is ^¬ assigns. Characterized in that the retaining elements are no longer inner ^¬ half of the expansion joints engage the side surfaces of the heat shield bricks, they are thermally not tet so highly polluted, whereby the safety of the bracket is increased.

The heat shield block according to the invention has the further advantage that a free design of the expansion joints limiting side surfaces of the heat shield brick is made possible by the internal mounting of Halteele ^¬ elements. This allows the pressure drop over the gap area to be raised stabili ^¬ hen and thus counteract the intake of hot gas.

The side surfaces can be formed, for example, without the previously required in the prior art groove, whereby the Gap must be supplied with less cooling air. Also, no cooling air is needed for cooling the arranged in the expansion joints holding elements longer. Adjacent heat shield ^bricks according to the invention can be formed, for example, with overlapping side surfaces.

The inventively designed engaging devices protect the resting inside the heat shield bricks holding heads of the holding elements from hot gases. Due to the ge ^¬ ringeren this thermal stress can be manufactured from a cheaper material. According to the invention engages at least one of the heat shield block holding Hal ^¬ teelement into an engagement means exclusively by the cold side. The heat shield block according to the invention may have one or more engagement devices. Loading vorzugt, the heat shield block according to the invention exactly ei ^¬ ne such a recess in the cold side.

The heat shield brick may consist of a ceramic material. Such ceramic heat shield bricks can be produced by casting, so that the at least one inventively formed recess in the cold side of the heat shield bricks can be formed during the casting of heat shield bricks from ^¬ .

It can also be considered advantageous that the recess is closed towards the hot side and towards the side surfaces.

This increases the protection for the holding the heat shield stone holding elements from hot gases. Mounting openings to the hot side, etc. are no longer necessary in the heat shield brick according to the invention. The assembly can be done for example by biasing the retaining structure attached to the support members with wax wedges, so that the heat shield brick is pushed in the region of the recess on the at least one holding portion of the prestressed holding element and rests on the support structure. During operation, the wax wedges melt, so that the at least one holding head inside the Recess under bias on one of the bearing surfaces of the at least one retaining bolt comes to rest.

It can also be considered advantageous that

the recess comprises at least two inner side surfaces. The inner side surfaces of the recess are substantially parallel to the side surfaces of the heat shield brick.

This facilitates the correct positioning of the recess over the retaining elements during assembly.

For example, the recess may have a quadrangular ^{Grundflä ¬} surface and four inner side surfaces which extend parallel to the side surfaces of the heat shield. An advantageous embodiment of the invention may provide that the recess has at least two oppositely angeord ^¬ designated locking bar.

This makes it possible to use the hitherto customary holding elements, which engage in pairs opposite the heat shield ^plate .

In order to simplify the structure of the heat shield stone, it may be provided that the oppositely disposed Hal- are formed teriegel by means of the profile of two opposite held ^¬ rer side surfaces of the recess.

The two oppositely disposed inner side surfaces of the recess can be used to form the retention tab examples game at the same height, each having a holding groove are formed entspre ^¬ accordingly the side surfaces in the prior art.

Another object of the invention is to provide a heat shield initially mentioned with which a particularly si ^¬ chere attachment is provided by at least one heat shield the stone to the supporting structure. The object is achieved in a heat shield of the type mentioned above in that the at least one particularly securely fixed heat shield brick is formed according to one of claims 1 to 5.

The heat shield according to the invention may comprise one or more of the ^¬ like design heat shield bricks. It may also be formed all the heat shield bricks of the heat shield ge ^¬ Mäss any one of claims 1 to 5 in ^¬ play. The heat shield bricks according to the invention can, for example, have exactly one recess opening toward the cold side. However, the heat shield bricks according to the invention can also have a plurality of engagement means opening to the cold side. The design of the retaining elements may vary depending on the position of the heat shield stones in the heat shield. Since the extending attachment grooves are fixed to the supporting structure by means of the holding elements ^heat shield bricks in general in closed rows of coaxial about a longitudinal axis of the combustion chamber around, only the last block of a row in a direction perpendicular to the support structure mounting direction on the support structure must be secured. If this heat shield brick is designed according to one of claims 1 to 5, the retaining element must be designed accordingly in order to fasten the retaining element to the support structure in a direction perpendicular to the support structure mounting direction or the at least one retaining head on the support surface ei ^¬ nes a retaining bolt position. The vorherge ^¬ Henden in series heat shield bricks may initially spaced from the rest of the row are fastened to the associated retaining elements, by which is inverted at least one recess in a tilting mounting movement on the holding portions of the holding members of the heat shield block in the field and then with ^¬ together with the in the recess protruding holding elements is pushed to the rest of the series zoom.

Advantageously, the recess is formed from ^¬ closed towards the hot side and to the side surfaces for protecting the holding elements. According to an advantageous embodiment of the invention, the recess has at least two oppositely arranged Hal ^¬ teriegel on.

This allows a pairwise opposite arrangement of the holding heads on the retaining bars, whereby a particularly stable attachment of the heat shield brick is made possible on the support structure ^¬ tur.

The opposite retaining bars can be advantageously produced particularly easily by being formed by means of the profile of two opposite inner side surfaces of the recess.

A further advantageous embodiment of the invention can provide that the heat shield brick is held by four retaining elements on the support structure. The holding elements are arranged in pairs opposite one another and come with their holding heads on the support surfaces of the oppositely arranged holding latch to the plant.

Another object of the invention is to provide a lined with a heat shield initially mentioned combustion chamber and a gas turbine with such a combustion chamber, which enables a particularly reliable fastening at least one hit ^¬ zeschildsteines to the support structure.

The object is achieved in a combustion chamber and a gas turbine of the type mentioned above in that the heat ^¬ shield is formed according to one of claims 6 to 10.

Further expedient configurations and advantages of the ^invention are the subject of the description of exemplary embodiments of the invention with reference to the figure of the drawing, wherein like reference symbols refer to identically acting components ver ^¬. It shows the

1 is a schematic representation of a gas turbine according to the prior art,

2 shows a detail of a heat shield according to the invention according to an embodiment in a schematic representation, and Figure 3 shows the heat shield shown in Figure 2 in front of a

Commissioning, wherein the holding elements for mounting the heat shield brick shown are biased with wax wedges. 1 shows a schematic sectional view of a gas turbine 1 ^¬ according to the prior art. The gas turbine 1 has inside a rotatably mounted about a rotation axis 2 rotor 3 with a shaft 4, which is also referred to as a turbine runner. Along the rotor 3 successively follow an intake housing 6, a compressor 8, a combustion system 9 with a number of combustion chambers 10, a turbine 14 and an exhaust housing 15. The combustion chambers 10 each include a burner assembly 11 and a housing 12, which is designed to protect against hot gases is lined with a heat shield 20.

The combustion system 9 communicates with a beispielswei ^¬ ring hot gas channel. There are several hinterei ^¬ Nander turbine stages form the turbine 14. Each Turbi ^¬ nenstufe is formed of blade rings. As seen in the flow direction of a working medium, a series of blades 18 follows in the hot runner of a row formed by vanes 17. The guide vanes 17 are fastened to an inner housing of a stator 19, whereas the running ^blades 18 of a row are attached to the rotor 3, for example by means of a turbine disk. ^¬ is coupled to the rotor 3, a generator, for example (not shown). During operation of the gas turbine, air is sucked in and compressed by the compressor 8 through the intake housing 6. The compressed air provided at the turbine-side end of the compressor 8 is led to the combustion system 9 where it is mixed with a fuel in the area of the burner assembly 11. The mixture is then burned by means of the burner ^arrangement 11 to form a working gas stream in the combustion system 9. From there, the working gas stream flows along the hot gas channel past the guide vanes 17 and the rotor blades 18. At the rotor blades 18, the working gas flow relaxed transferring its momentum, so that the run ^¬ blades 18 drive the rotor 3 and that the generator coupled to it (not shown). FIG. 2 shows a schematic representation of a

Section of a heat shield 22 ^{according to the} invention in longitudinal ^{¬ section} . The heat shield 22 includes a support structure 24 to which a plurality of heat shield bricks is releasably secured by means of holding elements. The illustrated section of the heat shield 22 shows a heat shield block 30 formed according to claims 1 to 5. The heat shield block 30 rests on the support structure 24 with a cold side 32. Ge ^¬ genüberliegend the cold side, the heat shield block 30 to be supplied with hot gases hot side 34th The cold side 32 and the hot side 34 are connected by side surfaces 36. In the cold side 32, a recess 38 which opens toward the cold side is arranged. The recess 38 is formed except for the opening 40 in the cold side 32 of the heat shield ^¬ stone stone 30 as a closed bag and comprises from the opening 40, starting in its interior two profiled, opposite side surfaces 42 and 44, which each form a retaining bolt 46 and 48 , The recess 38 thus forms an inside of the heat shield brick ^¬ arranged interior, which opens to the cold side and is closed to the side surfaces of the heat shield brick and the hot side. The recess 38 serves as an engagement device 50, in which retaining elements 26 and 28 are provided for fastening the heat shield block 30 to the support structure 24. to grab. For this purpose, the holding elements 26 and 28 are each guided with a fastening section 54, 56 in a fastening groove 58 in the support structure 24. The holding elements 26, 28 have on their side opposite the attachment portion end each have a support portion 60, which is pulled out of the loading ^¬ Firmness groove and a retaining head 62, engages behind a stop latch 46 48, so that the retaining head 62 of the holding element 26, 28 on a cold side 32 abge ^¬ facing bearing surface 64 of the retaining bolt 46, 48 comes to rest and the heat shield brick 30 releasably holds on the support structure 24. The heat shield brick 30 allows a particularly secure attachment to the support structure, since the retaining bolts 46, 48 and the bearing surfaces 64 are disposed inside the heat shield ^¬ stone 30. The heat shield 30 stone HAL Tenden holding elements 26 and 28 are thus be ^¬ Sonder effectively protected from hot gases.

To facilitate the installation of the heat shield brick 30 ver ^¬ run at least the inner side surfaces 42 and 44 of the engagement device parallel to the side surfaces 36 of the heat shield stone 30th

As shown in Figure 3, for mounting the heat shield ^¬ stone 30, the holding elements 26 and 28 are biased with wax wedges 68. The heat shield block 30 can then be turned over with the engagement device 50 over the raised holding sections 60 of the holding elements 26, 28, so that the holding heads 62 are located above the bearing surfaces 64 and spaced therefrom. When the heat shield 22 is acted upon by hot gas, the wax wedges 68 melt and the holding heads 62 are lowered onto the bearing surfaces 64, so that the fastening state is achieved as shown in FIG.

Claims

claims

1. heat shield brick (30) for a heat shield (20, 22) of a gas turbine (1),

which can be fastened by means of at least one retaining element (26, 28) in a releasable ^manner on a support structure (24),

- With one of the support structure (24) facing the cold side (32) and an opposite, with a hot medium

act on hot side (34),

- And with the cold side (32) with the hot side (34) connecting ^¬ side surfaces (36),

- Wherein the heat shield brick (30) for fastening the at least one retaining element (26, 28) on the heat shield brick (30) comprises at least one engagement device (50) with at least one retaining bolt (46, 48), which one of the cold ^¬ side ( 32) facing away from support surface (64),

characterized in that the engagement means (50) is formed as one of the cold side of ^¬ continuous recess (38), so that the recess forms a disposed in the heat shield block interior that opens to the cold side and closed to Seitenflä ^¬ chen out is, and the at least one Auflageflä ^¬ che (64) of the at least one retaining bolt (46, 48) of a ^¬ handle device (50) in the interior of the heat shield brick (30) is arranged in the region of the interior.

2. heat shield brick (30) according to claim 1,

d a d u r c h e c e n c i n e, the s

the recess (38) is closed towards the hot side (34) and towards the side surfaces (36).

3. heat shield brick (39) according to claim 1 or 2,

That is, the recess (38) includes at least two inner side surfaces (42, 44), the inner side surfaces (42, 44) of the

Recess (38) extend substantially parallel to the side surfaces (36) of the heat shield brick (30).

4. heat shield brick according to one of the preceding claims, characterized in that the recess (38) has at least two oppositely angeord ^¬ designated retaining bolt (46, 48).

5. heat shield brick (30) according to claim 4,

characterized in that the oppositely arranged retaining bolt (46, 48) with ^¬ tels the profile of two opposite inner side surfaces (42, 44) of the recess (38) are formed.

6. heat shield (22) for a combustion chamber (10) a Gasturbi ^¬ ne (1) with a support structure (24) and a number of heat shield bricks (30) which releasably secured to the support structure (24) by means of holding elements (26, 28) are,

wherein each heat shield brick (30) has a cold side (32) facing the support structure (24), a hot side (34) opposite the cold side (32) and a hot side (34) connecting the cold side (32) to the hot side (34). 36),

and at least one heat shield brick (30) has at least one engagement device (50) with at least one retaining bolt (46, 48), wherein the heat shield brick (30) is fastened to the support structure (24) by at least one fastening part (54, 56 ) on the day ^¬ structure (24) fixed holding element (26, 28) with a holding portion (60) with at least one holding head (62) on a cold side (32) facing away from bearing surface (64) of a retaining bolt (46, 48) rests

characterized in that at least one heat shield brick (30), the engagement means (50) is formed as a Ausneh ^¬ from the cold side Ausneh ^¬ tion (38), so that the recess forms a arranged in the heat shield brick interior, which opens to the cold side and to the Side surfaces is closed, and the at least one bearing surface (64) of the at least one retaining bolt (46, 48) of the engaging device tion (50) in the region of the interior space inside the heat ^¬ ing brick (30) is arranged.

7. heat shield (22) according to claim 6,

characterized in that the recess (38) to the hot side (34) and to the Seitenflä ^¬ Chen (36) is closed towards.

8. heat shield (22) according to claim 6 or 7,

characterized in that the recess (38) has at least two oppositely angeord ^¬ designated locking tab (46, 48).

9. heat shield (22) according to claim 8,

10. heat shield (22) according to one of claims 6 to 9, characterized in that the heat shield block (30) of four holding elements (26, 28) on the support structure (24) is held, wherein the holding elements (26, 28) in pairs opposite their holding heads (62) on the bearing surfaces (64) of the oppositely arranged retaining bolt (46, 48) come to rest.

11. combustion chamber (10), which is lined with a heat shield (20, 22),

characterized in that the heat shield (22) is formed according to one of claims 6 to 10 from ^¬ .

12. gas turbine (1) with at least one combustion chamber (10), d a d u c h e c e n e c e s e at least one combustion chamber (10) according to claim 11 is formed.