EP1533572A1 - Gas turbine combustion chamber and gas turbine - Google Patents

Abstract

The combustion chamber (1) has a cladding element (11) which is made of a heat-resistant non-oxide-based ceramic. The cladding element is fitted to the inside (4) of a housing part (3) facing a combustion chamber (2). The fixing device (13) is in the form of a screw connection, including a threaded ring.

Description

The invention relates to a gas turbine combustor with a Housing part and a cladding element formed from a ceramic, the means of attachment to a Combustion chamber facing inside of the housing part attached is. The invention further relates to a gas turbine with a Gas turbine combustor.

In a gas turbine is usually within a gas turbine combustor a covering for insulation and for Protection of a housing, also referred to as combustion chamber structure is against which resulting from the combustion thermal loads required. The thermal loads in the combustion chamber of the gas turbine combustor are in the Usually in the range of 1350 ° C or above and above in addition, e.g. in the context of a quick closure, strong Are subject to fluctuations. Such a burden is that metallic housings usually not suspendable. For this Reason is at a combustion chamber facing the inside of a Housing part mounted a panel. The disguise exists usually from a number of cladding elements. As a particularly advantageous one has a ceramic formed cladding element, in particular a heat shield, proved. An important advantage of a ceramic cladding element is its high temperature resistance.

One problem, however, is that a relatively high effort for the holder of such formed from a ceramic Cladding element is necessary. A common, ceramic Cladding element is based for example on a Alumina or silica ceramics, which is an excellent Temperature resistance has. A common in the rule plate-shaped formed cladding element However, to support relatively complex along its border, since the hitherto conventional ceramics insufficient strength which would be sufficient, the usual cladding element self-supporting even for frequent loads embody.

So far, therefore, to solve this problem metallic Cladding elements used for the cladding and possibly each provided with a ceramic coating (coating). Although such metallic heat shields with less Held as a ceramic heat shield and held are, however, have the metal alloys used so far a less advantageous compared to a ceramic Temperature resistance, so when using a metallic heat shield over a ceramic Heat shield a relatively high cost of cooling the metallic Heat shield must be operated, e.g. by using a complex temperature insulation layer and a correspondingly larger cooling air requirement.

Also a ceramic coating on a metallic heat shield can only partially eliminate these disadvantages, since due to the material dynamics under changing temperature conditions in the heat shield, the layer thickness of a coating and so that the temperature drop across the thickness of the coating on relatively small values is limited. So can a ceramic Coating at a combustion chamber side temperature of 1350 ° C in usually a temperature gradient over the coating of 100 ° C to 200 ° C, so that on a metallic Base of the heat shield still temperatures of 1150 ° C to 1250 ° C are expected. By use of metallic heat shields or ceramic coated Metallic heat shields is a satisfactory problem solution the above problem thus far not been possible.

It would be desirable to have a gas turbine combustor with a fairing, the sufficient temperature resistance for insulation and for protecting the housing parts and having the others as simply as possible facing a combustion chamber Can be mounted inside the housing part.

At this point, the invention begins, whose task it is to specify a gas turbine combustor and a gas turbine, in which a cladding element is designed in such a way that with as little support and / or maintenance as possible can be attached to a housing part.

This object is achieved by the invention by means of a gas turbine combustor solved the type mentioned, in the According to the invention, the ceramic a high temperature resistant, on a Non-oxide based ceramic is, and the attachment in Form of a screw connection is formed.

As previously explained, ceramics for a cladding element are based on an oxide compound such as a silicon oxide (SiO ₂ ) or an aluminum oxide (AlO ₂ , Al ₂ O ₃ ) and have a relatively low strength, so that their ductility in a modulus of elasticity is far below 0.1 * 10 ⁶ N / m ² . This is fundamentally advantageous with regard to the combustion chamber conditions. Because the temperature fluctuations and the temperature level in the combustion chamber usually causes significant temperature gradients within the cladding. These lead to stresses in each individual cladding element. The tensions can be kept as low as possible when using a conventional ceramic with the smallest possible modulus of elasticity. Conventional trim elements must be kept as described along their border, since they have low strength, ie a certain porosity because of their low modulus of elasticity. The elaborate mounting is necessary so that these mechanical loads can not withstand and fall apart.

In contrast, the present invention is based on the consideration from that when using a high temperature resistant, on a non-oxide based ceramic for a cladding element a fixture in the form of a simple Screw connection for the cladding element is possible. It has been shown that one on a non-oxide based ceramics a significantly lower creep behavior, has better resistance and higher ductility, than the conventional oxide ceramics used hitherto. It has surprisingly been found that the stresses occurring in such a cladding element due to the above-mentioned significant temperature gradients far smaller than previously thought. These Property of a non-oxide ceramic is still possible improve by the ceramics a hot gas oxidation lowering Having additive.

Advantageous developments of the invention are the subclaims to take and give in particular advantageous Possibilities to put the ceramic and the screw under with regard to the other advantages mentioned above.

It has proven to be advantageous, the attachment of a to form a single screw connection. When replacing the cladding element is thus only a single screw to solve. It has proved to be particularly advantageous that the cladding element by the screw connection is held in the middle. The attachment is therefore appropriate from a single, the fairing element centrally holding Screw connection. This will also be beneficial Tensions avoided by a clamping effect of laterally arranged screw could arise.

The ceramic is particularly advantageously a ceramic based on a SiC ₂ compound or a SiC compound or a SiN ₂ compound or an Si ₃ N ₄ compound. In principle, any Si _x C _y - or Si _x N _y compound comes into consideration. This type of ceramic has a particularly high temperature resistance and shows at the same time high mechanical strength yet a favorable voltage behavior. In addition, any other ceramic based on a ZC compound or a ZN compound may also be considered, wherein Z is any element of the periodic table or any compound thereof.

It has been found to be particularly suitable for the above application that the ceramic has a ductility in a modulus of elasticity of more than 0.15 * 10 ⁶ N / m ² . The oxide ceramics used hitherto have a modulus of elasticity which is far below 0.1 × 10 ⁶ N / m ² . It has been found within the scope of this development of the invention that, surprisingly, far fewer stresses occur in this development of the invention than would be expected from such a high modulus of elasticity. Advantageously, the elastic modulus can be selected in the range of 0.3 * 10 ⁶ N / m ² or a modulus of elasticity of up to 0.4 * 10 ⁶ N / m ² .

In a particularly preferable development of the invention the cladding element consists entirely of ceramic. This has the advantage that the cladding element three-dimensional homogeneous properties with the above Has advantages.

In addition, it has proven to be extra for more applications proved advantageous that the ceramic is a hybrid construction with a number of ceramic components, wherein at least one of the ceramic components is a non-monolithic Ceramic component is. In addition, such a Hybrid construction also contain a non-ceramic component, especially one that has a higher ductility compared to a ceramic component, for example a plastic component.

In a further development of the invention in terms of Screw connection, it has proved to be particularly advantageous that the screw is formed of a ceramic Has screw and / or nut. A mother can be formed by any screw, the fulfilled the function of a mother. For example, proves a coupling ring with shank and a thread on the Inside of the shaft as particularly appropriate. It is the ceramic advantageous a high temperature resistant, on one Non-oxide based ceramic. Particularly advantageous, a Ceramics of the above type are chosen, in particular the same ceramic that also used in the fairing becomes. In this way, the temperature behavior of the cladding element on the temperature behavior of the screw connection adapted, so that problems in the case of different Materials by different coefficients of thermal expansion occur, be avoided.

In particular, to the screw sufficient preload to give, the screw has advantageous also a spring element formed from a ceramic, the ceramic is a high temperature resistant, on a non-oxide based ceramic is. An advantage here is a the above ceramics used, in particular the same, which also for the cladding element and / or for the screw connection is used.

In the context of a particularly preferred embodiment of the invention the screw connection also has a centering, a clamping ring and a housing. The centering can advantageously be formed by a coupling ring.

The invention also leads to a gas turbine with a Gas turbine combustor according to one of the above-mentioned developments the invention.

FIG 1

eine besonders bevorzugte Ausführungsform einer Gasturbinenbrennkammer mit einer zu bevorzugenden Ausführungsform einer Verkleidung und einer Befestigung,

FIG 2

die besonders bevorzugte Ausführungsform einer Befestigung der Fig. 1 in einer Extrapolationszeichnung,

FIG 3

eine besonders bevorzugte Ausführungsform eines Verkleidungselements und die in Figur 2 gezeigte Befestigung bei einem in Figur 1 gezeigten Verkleidungselement.

Embodiments of the invention are described below with reference to the drawing. This is not intended to represent the embodiments significantly, but the drawing where appropriate for explanation, executed in a schematic and / or slightly distorted form. With regard to additions to the teachings directly recognizable from the drawing reference is made to the relevant prior art. In detail, the figures of the drawing show in:

FIG. 1

a particularly preferred embodiment of a gas turbine combustor with a preferred embodiment of a fairing and a fastening,

FIG. 2

the particularly preferred embodiment of a fastening of FIG. 1 in an extrapolation drawing,

FIG. 3

a particularly preferred embodiment of a cladding element and the attachment shown in Figure 2 in a cladding element shown in Figure 1.

1 shows a preferred embodiment of a gas turbine combustor 1 with a housing part 3 and a lining 5 formed from a ceramic. The housing part 3 has a metallic combustion chamber structure 7 and an insulation formed from insulating material, which is formed from a number of insulating parts 9. The cladding 5 is formed from a number of cladding elements 11. A cladding element 11 is attached by means of a fastening 13 to a combustion chamber 2 facing inside 4 of the housing part 3. In this case, a cladding element 11 is in each case attached to an insulating part 9 with a fastening 13. The cladding element 11 is formed in this embodiment of a high temperature resistant, non-oxide, based on a SiN ₂ compound ceramic whose ductility by a modulus of elasticity in the range of 0.3 * 10 ⁶ N / m ^{2 is} described. In this case, the cladding element 11 is made entirely of ceramics.

The attachment 13 is in the present embodiment formed in the form of a screw connection and is shown in FIG 2 in the context of an extrapolation drawing and in FIG. 3 shown and described in detail in the mounted state.

FIG. 2 shows the screw connection 13 of FIG. 1 in the frame an extrapolation drawing. The screw connection exists in this embodiment, a screw 15, a coupling ring 17, a spring element 19, another coupling ring 21, a clamping ring 23 and a housing 25. In addition the cladding element 11 and the insulating part 9 is shown.

The screw 15 has at its combustion chamber end one Screw head 27 on. On the shaft 30 of the screw 15 is a Thread 29 attached. At the end of the shaft 30, the Screw 15 a groove 31 and a through the groove 31 from Thread 29 separate clamping head 33 on. The screw 15 is arranged centrally to the cladding element 11 and the insulating part 9 and passes through the cladding element 11 in an opening 35 and the insulating part 9 in a further opening 37. Um. the screw head 27 in the openings 35, 37 as centrally as possible and safe to store the openings 35, 37 are conical arched, so that also on its underside conically flared screw head self-centered in the openings 35, 37 is located.

By the coupling ring 17, the screw 15 in the insulating part 9 and centered in the cladding element 11. The outer diameter of the coupling ring 17 is to the inner diameter of the openings 35, 37 adapted. The coupling ring has an annular Stop 41 and a shaft 39. The Überwurfring 17 acts as centering. On the inside of the Shaft 39, the coupling ring 17 can be made smooth as needed be or have a screw thread. Further Formations are not shown in FIG.

The spring element 19 is used to bias the screw 15 against the further coupling ring 21 and the clamping ring 23rd and the housing 25. In addition, the spring element 19 is similar thermal expansion of the screw compared to other components out.

The further coupling ring 21 also has an annular Stop 43 and a shaft 45, wherein the shaft 45th the further Überwurfrings 21 is formed shorter than the Shank 39 of the coupling ring 17. In the present case, the shaft carries 45 of the further Überwurfrings 21 on its inside Thread screwed onto the thread 29 of the screw 15 becomes. The further Überwurfring 21 takes over in the present case so the function of a mother. During assembly, the screw connection takes place the further coupling ring 21 and the screw 15th against the spring force of the spring element 19th

To secure the screw a clamping ring 23 against the resistance of the clamping head 33 of the screw 15 and over pushed the clamping head 33 away on the screw into the groove 31 and engages in the groove 31 of the screw 15 a. On This is the screw 13 against the bias secured the spring element 19.

To protect the intended for locking the screw 15 Überwurfrings 17, the spring element 19, the further coupling ring 21 and the clamping ring 23, a housing 25 is provided, this sitting on the shaft 30 of the screw 15 Parts includes and suitable for the screw 13 can be attached.

FIG. 3 shows that shown in FIG. 2 as extrapolation Screw 13 in one with the cladding element 11, Insulating part 9 and the combustion chamber structure 7 mounted state.

The parts of Figure 3 bear the same reference numerals as the parts of Figures 2 and 1.

It is clearly shown in FIG. 3 that the screw head 27 by its conical shape 51 on its underside in the opening 35 of the cladding element 11 centered self-centering is. The cladding element 11 itself also has a conical shape 53 on, in turn, in one of the molding 53 adapted conically curved further formation of the Dämmelements 9 centered self-centering. In this way the mounting effort for attachment 13 is greatly facilitated and the mounting of the attachment 13 in the housing part 3 ensured.

In the present embodiment, the shaft 30 extends the screw 15 free in the opening 37 of the insulating part 9 and also free in the shaft 39 of the coupling ring 17. Bei this embodiment carries the shaft 39 of the coupling ring 17 no internal thread. The on the shaft 30 of the screw 15th applied thread 29 engages in an unspecified thread in the shaft 45 of the further coupling ring 21 a. Of the Surge ring 21 is against the spring force of the spring 19 screwed the thread 29 on the shaft 30 of the screw 15. To secure the clamping ring 23 via the clamping head 33 of Screw pushed away and engages in the between thread 29 and clamping head 33 arranged groove 31 of the screw 15 a. In this way, the screw connection, i. the one inside the other engaging thread 29 in the shaft 43 of the coupling ring 21 and the thread guide 29 on the shaft 30 of the screw 15, against release by thermal expansion and others Loads secured. All on the shaft 30 behind the Insulating element 9 seated parts are housed in a housing 25. This protects the parts from damage. The shelter in a single housing 25 simplifies assembly. In this case, the clamping head 33 protrudes on the shaft 30 of the screw 15 from a central opening of the housing 25 also. In a not shown embodiment, the clamping head 33 of the screw 15 itself with another thread be provided. Such a further thread can for further Securing the housing and the screw serve.

In Figure 3, a detent 61 is further shown, the the insulating part 9 on the structural part 7 in the housing part 3 of the combustion chamber. 1 holds.

In the present embodiment, the cladding member 11 and the screw 15 are formed of the same high-temperature-resistant non-oxide ceramic based on a SiN ₂ compound. The temperature behavior of screw 15 and cladding element 11 is thus adapted to each other. In a further embodiment of the preferred embodiment shown in Figures 1 to 3, the further coupling ring 21 may be formed of the same ceramic as the screw 15 and the cladding element 11. In the embodiment shown, the coupling ring 21 is formed from another, but also high temperature resistant, non-oxide ceramic. This is also the case for the spring element 19. In this way, an advantageous adaptation of the screw connection 13 to the temperature environment on the back of the housing structure part 7 is achieved.

In summary, according to the present concept for a Gas turbine combustor 1 a cladding element 11 indicated the same time high temperature resistant and sufficient has mechanical strength, making it special on simple way can be fixed. this will achieved in a gas turbine combustor 1 with a housing part 3 and a cladding element formed of a ceramic 11, by means of a fastening 13 to a one Combustion chamber 2 facing inside 4 of the housing part 3 attached is. According to the present concept, the ceramic is a high temperature non-oxide based ceramic and the attachment 13 is in the form of a screw connection, in particular from a screw 15 and another Überwurfring 21 formed with a thread 29.

Claims (10)

Gas turbine combustor (1) with a housing part (3) and a cladding element (11) formed from a ceramic, which is attached by means of a fastening to a combustion chamber (2) facing inside (4) of the housing part (3), characterized in that
the ceramic is a high temperature resistant, non-oxide based ceramic and
the attachment in the form of a screw connection (13) is formed. Gas turbine combustor (1) according to claim 1 or 2, characterized in that
the attachment consists of a single the cladding element (11) centrally holding screw (13). Gas turbine combustor (1) according to claim 1 or 2, characterized in that
the ceramic is a ceramic based on a Si _x C _y compound or a Si _x N _y compound, or another ceramic based on a ZC compound or ZN compound, wherein Z is any element of the periodic table. Gas turbine combustor (1) according to one of claims 1 to 3, characterized in that
the ceramic has a ductility in a modulus of elasticity greater than 0.15 * 10 ⁶ N / m ² . Gas turbine combustor (1) according to one of claims 1 to 4, characterized in that
the ceramic is a hybrid construction having a number of ceramic components with at least one non-monolithic ceramic component. Gas turbine combustor (1) according to one of claims 1 to 5, characterized in that
the cladding element (11) consists entirely of the ceramic. Gas turbine combustor (1) according to one of claims 1 to 6, characterized in that
the screw connection (13) has a screw (15) formed from a ceramic and / or nut, wherein the ceramic is a high-temperature-resistant, non-oxide-based ceramic. Gas turbine combustor (1) according to one of claims 1 to 7, characterized in that
the screw connection (13) has a spring element (19) formed from a ceramic, the ceramic being a high-temperature-resistant, non-oxide-based ceramic. Gas turbine combustor (1) according to one of claims 1 to 8, characterized in that
the screw connection (13) has a centering, a clamping ring (23) and a housing (25). Gas turbine with a gas turbine combustion chamber (1) after a of claims 1 to 9.

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