CN1675502A - Gas turbine combustion chamber - Google Patents

Abstract

A gas turbine combustion chamber (4) comprises a manhole (27) as access to a combustion chamber interior (24), which may be sealed with a manhole cover (28). The manhole (27) comprises an inner cooling chamber and may thus take particularly high thermal loads.

Description

gas turbine combustor

The invention relates to a combustion chamber of a gas turbine with a manhole, which can be closed with a manhole cover, as an entry into the chamber of the combustion chamber.

Gas turbines are used to drive generators or working machinery in many fields. In this case, the internal energy in the fuel is used to rotate the turbine shaft. For this purpose, fuel is combusted in a combustion chamber, into which air compressed by an air compressor is simultaneously fed. The high-temperature and high-pressure working medium produced by the combustion of fuel in the combustion chamber flows through a turbine unit connected downstream of the combustion chamber and expands there to perform work.

When designing such gas turbines, in addition to achieving a certain power, the design goals usually also include achieving a particularly high efficiency. For thermodynamic reasons, an increase in efficiency can substantially be achieved by increasing the outlet temperature, ie by increasing the temperature of the working medium exiting the combustion chamber and entering the turbine unit. For such gas turbines, therefore, temperatures of approximately 1200° C. to 1300° C. have been achieved and can also be achieved.

The combustion chamber, which is exposed to such high temperatures during operation of the gas turbine, should be accessible for personnel, for example, for inspection purposes. Disclosed among the German patent documents 199 24 607 A1 is a gas turbine with a combustion chamber, which has at least a part of the region that can be inspected by the manhole entrance. In the German patent document 198 09 568 A1, a gas turbine with an annular combustion chamber is disclosed, wherein an entrance (manhole) is provided in the flame chamber through which personnel can enter the flame chamber. However, manholes into the combustion chamber are generally not used, especially in gas turbines with combustion temperatures as high as 1200° C. to 1300° C., since such manholes may not be able to withstand the thermal load in the combustion chamber or at least not ensure the tightness of the combustion chamber. This applies in particular to combustion chambers equipped with combustion chamber linings, so-called liners. Therefore, particularly troublesome dismantling work is required in order to allow personnel to enter the combustion chamber.

The object of the present invention is to provide a gas turbine combustor, which can be applied to a gas turbine with a particularly high combustion temperature, and which can be easily entered by personnel.

This object is achieved according to the invention by a gas turbine combustor having the features of claim 1 . The combustion chamber of the gas turbine has a manhole closed with a manhole cover as access to the combustion chamber, wherein the manhole cover has an internal cooling chamber. The inner cooling chamber, ie the cooling chamber in the manhole cover, enables targeted cooling of the manhole cover which closes the combustion chamber. The manhole cover can thus also be used under high thermal loads in the combustion chamber without unacceptable excessive deformations, thus ensuring a tight closure of the combustion chamber with the manhole cover in all operating states Indoor cavity.

In addition to the manhole cover, the combustion chamber walls are preferably internally cooled at least in those regions of the gas turbine combustion chamber which are exposed to particularly high thermal loads. In this case, the combustion chamber wall has so-called wall cooling chambers. Preferably, the inner cooling chamber of the manhole cover can communicate with the wall cooling chamber of the combustion chamber wall, for example by means of a connecting channel. In this way, at least similar thermal conditions can easily be established on the components surrounding the combustion chamber, in particular on the manhole cover and the combustion chamber wall surrounding the manhole cover.

According to a preferred refinement, it is particularly simple to connect the inner cooling chamber of the manhole cover with the wall cooling chamber of the combustion chamber wall directly by inserting the manhole cover into the manhole. This makes it possible in particular for the wall cooling chamber of the combustion chamber wall to transition into the inner cooling chamber of the manhole cover without a reduction in cross-section. Preferably, the entire chamber wall of the combustion chamber of the gas turbine together with the manhole cover forms a uniform cooling chamber.

According to a preferred design, the manhole cover or at least one single cover part of the manhole cover (for example, the cover lining of the inner cooling chamber that closes the manhole cover facing the combustion chamber) faces the combustion chamber. The chamber is supported by fastening elements, which simultaneously fasten a lining element adjacent to the manhole cover to the combustion chamber wall. Through the multiple functions of the fixing element, the number of fixing elements in the combustion chamber can be reduced to a minimum.

Preferably, the cross-section of the fixing element is at least substantially U-shaped, wherein a first leg of the U-shaped fixing element supports the individual cover parts of the manhole cover, and the other leg of the U-shaped fixing element supports the individual cover parts of the manhole cover. The lining element is fastened to the combustion chamber wall. The fixing element is preferably rail-shaped as a whole. By designing the fixing element as a U-shaped rail, both sufficient stability and sufficient elasticity are achieved.

The fastening element is preferably fastened to the combustion chamber wall in such a way that a section of the fastening element, in particular a U-shaped leg, protrudes into the manhole and faces the cover lining of the manhole cover of the combustion chamber. It is held there and the manhole cover can be removed from the manhole without loosening the fastening elements. The advantage of this is that all the fixing elements that fix the lining element and the cover lining to the combustion chamber wall or the manhole cover need only be fixed at once, and the personnel can pass through without removing a single fixing element. Manholes enter the gas turbine combustion chamber.

The advantages of the invention are primarily that, due to the provision of the inner cooling chamber, the manhole cover can withstand high thermal loads and that the manhole cover with its inner cooling chamber can be removed from the manhole particularly easily.

An embodiment of the present invention will be described in detail below with the help of the accompanying drawings. In the accompanying drawings:

Fig. 1 is a half sectional view of a gas turbine;

FIG. 2 is a partial cross-sectional view of a combustor of the gas turbine shown in FIG. 1 .

In both figures, the same components are identified with the same reference numerals.

The gas turbine 1 shown in FIG. 1 has a compressor 2 for supplying combustion air, a combustor or a gas turbine combustor 4 , and a turbine 6 for driving the compressor 2 and a generator or working machine not shown in the figure. For this purpose, the turbine 6 and the compressor 2 are mounted on a common turbine shaft 8 , also referred to as the turbine rotor. The generator or working machine is also connected to said turbine shaft, which is mounted rotatably about its central axis 9 .

The combustion chamber 4 is equipped with a number of burners 10 for igniting liquid or gaseous fuels. In addition, lining elements 25 are provided on the inner wall or combustion chamber wall 23 of the combustion chamber.

The turbine 6 has rotatable rotor blades 12 connected to the turbine shaft 8 . The moving blades 12 are arranged annularly on the turbine shaft 8 and thus form moving blade groups. In addition, the turbine 6 also includes stationary guide vanes 14 which are likewise fastened to the inner housing 16 of the turbine 6 so as to form a set of guide vanes in the form of a ring. The rotor blades 12 here drive the turbine shaft 8 by transmitting the momentum of the working medium M flowing through the turbine 6 . The guide vanes 14 are used to guide the flow direction of the working medium M between every two moving blade sets or moving blade circles connected back and forth along the flow of the working medium M. A pair of blade sets consisting of a ring of guide blades 14 or a set of guide blades connected one behind the other and a ring of moving blades 12 or a set of moving blades is also referred to herein as a turbine stage.

Each guide vane 14 has a platform 18 , also referred to as a blade root 19 , which is arranged as a wall element on the inner housing 16 of the turbine 6 for fastening the respective guide vane 14 . In contrast, the platform 18 is a component subject to a strong heat flow, since it forms the outer boundary of the hot gas channel for the working medium M flowing through the turbine 6 . Each rotor blade 12 is fixed in a similar manner to the turbine shaft 8 via a blade root 19 , also referred to as a platform 18 , wherein each blade root 19 supports a profiled airfoil 20 extending along the blade axis.

A respective guide ring 21 is arranged on the inner housing 16 of the turbomachine 6 between the platforms 18 of the guide vanes 14 of two adjacent guide vane sets arranged at a distance from one another. Here, the outer surface of each guide ring 21 is likewise exposed to the thermal action of the working medium M flowing through the turbomachine 6 and these guide rings are radially spaced from the outer end 22 of the rotor blade 12 opposite it by a gap. The guide rings 21 arranged between adjacent guide vane groups here serve in particular as housing elements which protect the inner wall 16 or other housing components from overheating by the hot working medium M flowing through the turbine 6 .

In order to achieve a higher efficiency, the gas turbine 1 is designed for higher outlet temperatures of approximately 1200° C. to 1300° C. (ie the temperature of the working medium M flowing out of the combustion chamber 4 ). To achieve this, internal cooling of the combustion chamber wall 23 is required. In this case, the combustion air flows counter to the direction of the working medium M (i.e. the hot gas flow) through the wall cooling chamber formed between the combustion chamber wall 23 and the lining element 25 fixed thereon surrounding the combustion chamber 24 chamber 26 to the burner 10 . At the same time, the desired combustion air is heated by this cooling of the combustion chamber.

FIG. 2 shows the combustion chamber wall 23 with a manhole 27 in a partial sectional view, into which manhole cover 28 is inserted. The manhole cover 28 has a cover part 29 which is designed similarly to the combustion chamber wall 23 and a cover lining 30 . An inner cooling chamber 31 of the manhole cover 28 is enclosed between the cover upper part 29 and a cover inner lining 30 , also referred to as the individual cover part. Correspondingly, a wall cooling chamber 26 is also enclosed between the combustion chamber wall 23 and the lining element 25 fastened thereto. The inner cooling chamber 31 of the manhole cover 28 communicates with the wall cooling chamber 26 of the combustion chamber wall 23 so that the combustion air can flow unhindered perpendicular to the plane shown in the figure.

At its edge, the cover part 29 has a projection 33 with which it can be inserted into a corresponding fastening recess 34 of the combustion chamber wall 23 . The basic shape of the manhole cover 28 is generally rectangular. To increase the stability, the cover part 29 and the combustion chamber wall 23 gradually thicken in the region of their connection (ie in the region of the projection 33 and the fastening recess 34 ) towards the combustion chamber 24 . In the thickened or reinforced region 35 of the cover part 28 there is a contact surface 36 against which the cover lining 30 rests with the lining edge 37 . The lining edge 37 is connected to and bent integrally with the lining main surface 38 . Similarly, the lining edge 41 of the lining element 25 bears against the contact surface 39 of the reinforced or thickened region 40 of the combustion chamber wall 23 .

The manhole cover 28 is supported towards the combustion chamber outer side 42 by a fastening device (not shown). The cover lining 30 and the lining element 25 are supported towards the combustion chamber 24 by a fastening element 43 designed as a U-shaped rail. In this case, the first leg 44 of the U-rail rests against the lining edge 37 of the manhole cover 28 and the second leg 45 of the U-rail rests against the lining edge 41 of the lining element 31 . The two legs 44 , 45 of the U-rail are also referred to as sections of the fastening element 43 . In order to support the manhole cover 28 facing the combustion chamber 24 , overall only two fastening elements 43 are required. These fastening elements 43 are fastened to the combustion chamber wall by means of screws 46 which penetrate the thickened region 40 of the combustion chamber wall 23 .

Screws 46 are screwed from the combustion chamber space 24 into the combustion chamber wall 23 . No additional fastening of the lining element 31 at the thickened region 40 is required. Because, the U-shaped fastening element 43 that is fixed on the combustion chamber wall 23 with bolt 46 is not only sufficient to fix the lining element 25 on the combustion chamber wall 23, but also supports the cover lining 30 facing the combustion chamber 24. . The inner linings 25 , 30 , also referred to as linings, are seam-sealed by fastening elements 43 . The escape of cooling air is prevented in the region of the fastening element 43 . If cooling air escapes from the wall cooling chamber 26 or the inner cooling chamber 31 on the lining edge 37 or lining edge 41, the escaping cooling air is hindered by the U-shaped fixing element 43 and thus cannot flow into the In the chamber 24 of the combustion chamber. The cooling air blocked by the U-shaped fixing element 43 can flow unhindered to the burner 10 along the fixing element 43 designed as a track.

To remove the manhole cover 28 from the manhole 27 it is not necessary to remove the fastening element 43 or loosen the screws 46 . This is achieved by means of an engagement configuration, by means of which fastening element 43 supports lining element 25 as well as cover lining 30 facing combustion chamber 24 . The fixing element 43 bridges the gap between the lining edge 37 of the manhole cover 28 and the lining edge 41 of the lining element 25 when the combustion chamber 4 is closed with the manhole cover 28, so that the hot working medium M cannot flow from the combustion chamber. The cavity 24 flows out onto the combustion chamber wall 23 or the cover part 29 . The combustion chamber 4 is thus fully lined with the manhole cover 28 .

Claims (7)

1. a gas-turbine combustion chamber (4), its have (a 28) sealing by manhole cover, as the manhole (27) that enters the inlet of combustion chamber inner chamber (24), it is characterized in that described manhole cover (28) has interior cooling chamber (31).

2. gas-turbine combustion chamber as claimed in claim 1 (4) is characterized in that, combustion chamber locular wall (23) has wall cooling chamber (26).

3. gas-turbine combustion chamber as claimed in claim 2 (4) is characterized in that, the interior cooling chamber (31) of described manhole cover (28) can be communicated with the wall cooling chamber (26) of described chamber wall (23).

4. gas-turbine combustion chamber as claimed in claim 3 (4), it is characterized in that the interior cooling chamber (31) of described manhole cover (28) inserts in the described manhole (27) by described manhole cover (28) and directly is communicated with the wall cooling chamber (26) of described chamber wall (23).

5. as each described gas-turbine combustion chamber (4) in the claim 2 to 4, it is characterized in that, be provided with a retaining element (43), at least one single cover (29,30) that this retaining element supports described manhole cover (28) makes it towards described combustion chamber inner chamber (24), simultaneously a liner element (25) adjacent with described manhole cover (28) is fixed on the described chamber wall (23).

6. gas-turbine combustion chamber as claimed in claim 5 (4), it is characterized in that, the cross section of described retaining element (43) takes the shape of the letter U at least basically, wherein, the first limit leg (44) of this U-shaped retaining element supports described single cover (29,30), and the another side leg (45) of this U-shaped retaining element is fixed described liner element (25).

7. as claim 5 or 6 described gas-turbine combustion chambers (4), it is characterized in that, a section (44,45) of described retaining element (43) stretches in the described manhole (27) like this, make that the lid liner (30) of described manhole cover (28) is supported (24) towards described combustion chamber inner chamber, and can take off described manhole cover (28) from described manhole (27).

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