EP2242915B1 - Gas turbine having an improved cooling architecture - Google Patents

Description

Technical area

The present invention relates to the field of thermal machines. It relates to a thermal machine according to the preamble of claim 1.

State of the art

Gas turbines, such as those offered by the applicant under, for example, the type designation GT13E2, are operated with an annular combustion chamber. The combustion itself is preferably, but not exclusively premix burner (hereinafter referred to as burner), as for example from EP-A1-321809 or EP-A1-704,657 These publications and the derived further development of these premix burners are an integral part of this application. Such an annular combustion chamber, for example, goes out DE-A1-196 44 378 which, in the Fig. 1 This application is reproduced in sections. In the Fig. 1 shown gas turbine 10 has a turbine housing 11, which encloses a filled with compressed combustion air plenum 14 in the combustion chamber 15. Concentrically around the central rotor 12 around the plenum 14, the annular combustion chamber 15 is arranged, which merges into a hot gas duct 22. The space is bounded inwardly by an inner shell 21 'and outwardly by an outer shell 21. Inner shell 21 'and outer shell 21 are each divided into a parting plane in the upper part and a lower part. The top and bottom of the inner and outer shell 21 ', 21 are connected in the parting plane so that an annular space is formed, which directs the hot gas generated by the burners 16 on the blades 13 of the turbine. The parting line is for assembly and disassembly of the machine required. The combustion chamber 15 itself is lined with special wall segments 17.

Inner and outer shell 21 ', 21 are convectively cooled in the embodiment described. In this case, cooling air, which enters the plenum 14 coming from the compressor as a compressor air flow 23, flows primarily in the opposite direction of flow of the hot gas in the hot gas duct 22 From the plenum 14 from this cooling air then flows through an outer and inner cooling channel 20 and 20 ', which cooling channels through the shells 21, 21 'are formed at a distance surrounding cooling shirts 19, 19'. The cooling air flows in the cooling channels 20, 20 'along the shells 21, 21' in the direction of the combustion chamber hood surrounding the combustion chamber 15. There, the air is then available to the burners 16 as combustion air.

Of the burners 16, the hot gas flows to the turbine (blades 13) and thereby along the hot gas side surfaces of the inner and outer shell 21 ', 21. However, the flow along these surfaces is not homogeneous, but is influenced by the arrangement of the burner 16th

Inner and outer shell 21 ', 21 are loaded both thermally and mechanically. These loads, also in connection with the mode of operation, determine the service life of the inner and outer shell 21 ', 21 and the resulting inspection intervals. The above-mentioned non-uniformities of the flow occur both on the hot gas side and on the cooling air side. The hot gas side nonuniformities result primarily from the burner assembly. The cooling air side irregularities are primarily caused by internals in the cooling channels 20, 20 '.

The EP 1 482 246 A1 describes a combustion chamber with a combustion chamber side facing combustion chamber wall, are attached to the design for burner temperatures of up to 1500 ° C heat shield elements via fastening means, wherein the combustion chamber wall and the combustion chamber wall facing surface of the heat shield elements include a cooling gap, with the cooling air opposite flow direction flows to the hot gas flow within the combustion chamber. In order to provide an intensified local cooling effect to particularly highly stressed combustion chamber wall regions, flow elements narrowing the flow cross section of the cooling channel are inserted along the cooling channel on the sides of the combustion chamber wall. An attachment of the flow elements along the combustion chamber wall by means of suitable form-locking connections (see column 9, lines 24 to 28). The flow elements are arranged within the cooling channel such that highly thermally stressed wall sections of the heat shield element are subjected to increased cooling by increasing the cooling air flow in this area by reducing the cross section.

From the Japanese publication JP 2003286863 A shows a double-walled combustion chamber wall, with an outer shell delimiting the hot gas channel and a cooling jacket surrounding the outer shell. To increase the cooling effect, the cooling shirt according to D2 is permeated with perforations, so that the prerequisite for an impingement air cooling of the outer shell of the combustion chamber is realized.

The EP 0 599 055 A1 describes a gas turbine combustion chamber with a perforated plate 3 which surrounds the combustion chamber wall at a distance, by means of which an impingement cooling air situation of the combustion chamber wall 3 is likewise created.

EP 1 207 273 A2 , for impingement air cooling of a combustor wall 10 surrounding the hot gas passage, provides a perforated plate assembly 122 which includes a plurality of holes 26, a portion of the holes being provided with cap-like baffles capable of passing an increased portion of cooling air flow vertically through the respective holes.

The US 3,652,181 also describes an impingement air cooling for the combustion chamber wall surrounding the hot gas duct.

Presentation of the invention

It is an object of the invention to design a thermal engine, in particular a gas turbine, so that the load on the system parts subject to particular thermal stress is made uniform, thereby extending the life of the system as a whole.

The object is solved by the entirety of the features of claim 1. It is essential for the invention that this uniformity is achieved by an intervention in the cooling by the cooling jacket has a local bulge in the form of a dome to compensate for local unevenness in the thermal load of the shell or in the flow of the cooling medium in the cooling channel, which results in a local enlargement of the cooling channel cross section. As a result, the cooling can be locally enhanced in a simple manner in order to reduce corresponding local thermal overloads.

An embodiment of the invention is characterized in that on the outside of the shell in the cooling channel protruding internals are present, and that caused by the internals local constriction of the cooling channel is compensated by a corresponding local contouring of the Kühlhemds.

In particular, the local contouring of the cooling skirt may include a dome extending in the cooling jacket over the region of the internals and projecting outwards.

Another embodiment of the invention provides that to compensate for a occurring at a certain place, increased thermal stress on the shell or to compensate for a caused by internals local constriction of the cooling channel at this location means for introducing additional cooling air in the Cooling channel are provided, wherein, when the cooling jacket is acted upon on the outside of under elevated pressure cooling medium, the means for introducing additional cooling air into the cooling channel preferably comprise cooling holes in the cooling jacket.

In particular, the thermal engine in question may be a gas turbine having a combustion chamber and the hot gas passage from the combustion chamber leading to a first series of blades. In addition, the combustion chamber may be annular and separable in a parting plane, wherein the hot gas channel is bounded by an outer shell and an inner shell, and by an appropriate inner and outer Kühlhemd an inner and outer cooling channel is formed.

Preferably, the gas turbine comprises a compressor for compressing sucked combustion air, wherein the output of the compressor communicates with a plenum, and the combustion chamber is arranged with the adjoining hot gas channel and the adjacent cooling channels in plenum and surrounded by the plenum that compressed air from the Plenum flows against the hot gas flow in the hot gas channel through the cooling channels to burners arranged on the combustion chamber. In addition, the burners may advantageously be designed as premix burners, in particular as double-cone burners.

Brief explanation of the figures

Fig. 1

den Längsschnitt durch eine gekühlte Ringbrennkammer einer Gasturbine nach dem Stand der Technik;

Fig. 2

in mehreren Teilfiguren 2A bis 2D einen Kühlkanal ohne innen liegende Hindernisse mit einer lokalen (Dom-artigen) Anpassung im Kühlhemd (Fig. 2A) gemäss einem Ausführungsbeispiel der Erfindung, und ohne Anpassung (Fig. 2B), sowie einen mit Rippen ausgestatteten Kühlkanal mit einer lokalen (Dom-artigen) Anpassung im Kühlhemd gemäss einem anderen Ausführungsbeispiel der Erfindung (Fig. 2C), und ohne Anpassung (Fig. 2D);

Fig. 3

in mehreren Teilfiguren 3A bis 3D einen Kühlkanal mit innen liegenden Einbauten mit einer lokalen (Dom-artigen) Anpassung im Kühlhemd gemäss einem weiteren Ausführungsbeispiel der Erfindung, in Strömungsrichtung gesehen (Fig. 3A) und quer zur Strömungsrichtung gesehen (Fig. 3B), sowie die Anordnung gemäss Fig. 3A,B mit zusätzlicher Kühlluftzuführung gemäss einem anderen Ausführungsbeispiel der Erfindung, in Strömungsrichtung gesehen (Fig. 3C) und quer zur Strömungsrichtung gesehen (Fig. 3D);

Fig. 4

in einer perspektivischen Seitenansicht ein in einer Trennebene teilbares Kühlhemd für eine Gasturbinen-Ringbrennkammer mit lokalen Anpassungen gemäss einem anderen Ausführungsbeispiel der Erfindung;

Fig. 5

einen vergrösserten Ausschnitt des Kühlhemds aus Fig. 4 mit einem die lokalen Anpassungen aufweisenden Ringsegment; und

Fig. 6

für sich genommen das die lokalen Anpassungen aufweisenden Ringsegment aus Fig. 5.

The invention will be explained in more detail with reference to embodiments in conjunction with the drawings. All elements not required for the immediate understanding of the invention have been omitted. The same parts are in the different figures with the provided the same reference numerals. The flow direction of the media is indicated by arrows. Show it

Fig. 1

the longitudinal section through a cooled annular combustion chamber of a gas turbine according to the prior art;

Fig. 2

in several subfigures 2A to 2D a cooling channel without internal obstacles with a local (dome-like) adaptation in Kühlhemd ( Fig. 2A ) according to an embodiment of the invention, and without adaptation ( Fig. 2B ), as well as a finned cooling channel with a local (dome-like) adaptation in Kühlhemd according to another embodiment of the invention ( Fig. 2C ), and without adaptation ( Fig. 2D );

Fig. 3

in several sub-figures 3A to 3D, a cooling channel with internal internals with a local (dome-like) adaptation in Kühlhemd according to a further embodiment of the invention, as seen in the flow direction ( Fig. 3A ) and seen transversely to the flow direction ( Fig. 3B ), as well as the arrangement according to Fig. 3A, B with additional cooling air supply according to another embodiment of the invention, seen in the flow direction ( Fig. 3C ) and seen transversely to the flow direction ( Fig. 3D );

Fig. 4

in a perspective side view of a divisible in a dividing plane cooling jacket for a gas turbine annular combustion chamber with local adjustments according to another embodiment of the invention;

Fig. 5

an enlarged section of the cool shirt Fig. 4 with a ring segment having the local adjustments; and

Fig. 6

taken individually, the ring segment having the local adjustments Fig. 5 ,

Ways to carry out the invention

In the context of the invention, the distribution of the cooling air is influenced by a (local) adaptation of the cooling channel cross-sectional profile in conjunction with existing installations in the cooling channel so that adjusts a local adjustment of the cooling air mass flow or a local adjustment of the heat transfer between shell and cooling air. The cooling channel cross section is defined by the existing contour of the inner or outer shell and a modified, i. Contouring adapted to the shape of the cooling air sheets (cooling shirts), which are mounted on the inner and outer shell.

In Fig. 2B is shown in cross-section transverse to the flow direction of the cooling air 24 and the flowing in the opposite direction of hot gas 25 between the shell 21 and the cooling jacket 19 formed cooling channel having a constant in the illustrated section flow cross-section. According to one embodiment of the invention, a local change of the flow cross section can now be brought about by providing the cooling jacket (locally) with a bulge in the form of a dome 26. By the dome 26, which can extend in the flow direction (perpendicular to the plane) over a greater length (see Fig. 3B and 3D ), results in a local enlargement of the cooling channel cross-section, which leads to a locally improved cooling and thus can contribute to the reduction of an occurring at this point increased thermal load.

Such a step (from Fig. 2D to Fig. 2C ) is particularly suitable when in the cooling channel 20 as obstacles inwardly projecting ribs 27 on the outside of the shell 21 are present.

Such a local dome 26 lends itself to the local improvement of the cooling, in particular, if - as in FIGS. 3A and 3B shown - special, the cooling flow obstructing internals 28 in the cooling channel 20 are present. The dome 26 is then conveniently adapted in width and length to the disabling internals 28.

In addition or as an alternative to the dome-like local extension (26) of the cooling channel 20 but can also according to 3C and 3D additional cooling air 29 are guided through corresponding openings in the cooling jacket 19 to the critical point. For this purpose, it is necessary that on the outside of the Kühlhemdes cooling air under higher pressure, in particular from the surrounding plenum 14, is available.

In 4 to 6 is shown in a perspective side view (divisible in a dividing plane 31, outer) Kühlhemd 19 for a gas turbine annular combustion chamber with local adjustments according to another embodiment of the invention. The cooling jacket 19 is composed of a plurality of similar segments 30. In the immediate vicinity of the parting plane 31 is in each case a selected segment 32 is provided, which has local modifications to optimize the cooling. As in particular in Fig. 5 and 6 can be seen, this selected segment 32, which adjoins the parting plane 31 and includes a corresponding terminal strip 33, on the one hand equipped with an elongated dome 26. On the other hand, both within the dome 26 and in an extension line of the dome 26 cooling openings 35 and 34 are arranged in the segment sheet, by - analogous to 3C and 3D - Additional cooling air can enter from outside into the cooling channel.

Furthermore, it is conceivable within the scope of the invention to change the geometry of the ribs 27 or of the internals 28, in particular also in combination with modifications of the cooling jacket and with cooling openings for the entry of additional cooling air.

LIST OF REFERENCE NUMBERS

10

gas turbine

11

turbine housing

12

rotor

13

blade

14

plenum

15

combustion chamber

16

burner

17

wall segment

18

combustion chamber hood

19

outer cooling shirt

19 '

inner cooler shirt

20

outer cooling channel

20 '

inner cooling channel

21

outer shell (hot gas channel)

21 '

inner shell (hot gas channel)

22

Hot-gas duct

23

Compressor air flow

24

cooling air

25

hot gas

26

Dom (cooling shirt)

27

rib

28

fixtures

29

additional cooling air

30.32

Segment (cooling shirt)

31

parting plane

33

connecting strips

34.35

cooling vent

Claims (14)

1. Thermal machine which comprises a hot-gas channel (22) which is bounded on the outside by a shell (21, 21'), wherein a cooling channel (20, 20') is formed on the outside of the shell (21, 21') for convection cooling by means of a cooling medium, in particular cooling air (24), which cooling channel (20, 21) is formed by the shell (21, 21') and a cooling shirt (19, 19') which surrounds the shell (21, 21') on the outside, characterized in that, in order to compensate for local nonuniformities in the thermal load on the shell (21, 21') and/or in the flow of the cooling medium in the cooling channel (20, 20'), the cooling shirt (19, 19') has a local outward bulge in the form of a dome, which outward bulge results in a local increase in the cooling channel cross section.
2. Thermal machine according to Claim 1, characterized in that fittings (28) which project into the cooling channel (20, 20') are provided on the outside of the shell (21, 21'), and in that the local constriction, which is caused by the fittings (28), of the cooling channel (20, 20') is compensated for by corresponding local contouring of the cooling shirt (19, 19').
3. Thermal machine according to Claim 2, characterized in that the local contouring of the cooling shirt (19, 19') comprises the dome (26), which is curved outwards and extends over the area of the fittings (28), in the cooling shirt (19, 19').
4. Thermal machine according to Claim 1 or 2, characterized in that, in order to compensate for an increased thermal load which occurs at a specific point on the shell (21, 21'), or in order to compensate for a local constriction, which is caused by fittings (28), in the cooling channel (20, 20'), means (34, 35) for introduction of additional cooling air (29) into the cooling channel (20, 20') are provided at this point.
5. Thermal machine according to Claim 4, characterized in that the cooling shirt (19, 19') has a cooling medium at an increased pressure applied to the outside, and in that the means for introduction of additional cooling air (29) into the cooling channel (20, 20') comprise cooling openings (34, 35) in the cooling shirt (19, 19').
6. Thermal machine according to one of Claims 1 to 5, characterized in that the thermal machine is a gas turbine (10) with a combustion chamber (15), and in that the hot-gas channel (22) is guided from the combustion chamber (15) to a first row of stator blades (13).
7. Thermal machine according to Claim 6, characterized in that the combustion chamber (15) is annular and can be separated on a separating plane (31), in that the hot-gas channel (22) is bounded by an outer shell (21) and an inner shell (21'), and in that an inner cooling channel (20) and an outer cooling channel (20') are formed by a corresponding respective inner cooling shirt (19) and outer cooling shirt (19').
8. Thermal machine according to Claim 7, characterized in that the gas turbine (10) comprises a compressor for compression of inductive combustion air, in that the output of the compressor is connected to a plenum chamber (14), and in that the combustion chamber (15) is arranged with the hot-gas channel (22), which is connected to it, and the adjacent cooling channels (20, 20') in the plenum chamber (14), and is surrounded by the plenum chamber (14), such that compressed air flows from the plenum chamber (14) in the opposite direction to the hot-gas flow in the hot-gas channel (22), through the cooling channels (20, 20') to burners (16) which are arranged on the combustion chamber (15).
9. Thermal machine according to one of Claims 1-8, characterized in that the burners (16) are in the form of premixing burners.
10. Thermal machine according to Claim 9, characterized in that the premixing burner (16) comprises at least two hollow partial conical shells which are interleaved in one another in the flow direction and complement one another to form a body, in that the cross section of the internal area which is formed by the hollow partial conical shells increases in the flow direction, in that the respective longitudinal axes of symmetry of these partial conical shells run offset with respect to one another, in such a manner that the adjacent walls of the partial conical shells form tangential slots or channels in their longitudinal extent for a combustion air flow to flow into the internal area which is formed by the partial conical shells.
11. Thermal machine according to Claim 9, characterized in that the premixing burner (16) comprises at least two hollow partial shells which are interleaved in one another in the flow direction and complement one another to form a body, in that the cross section of the internal area which is formed by the hollow partial shells runs cylindrically or quasi-cylindrically in the flow direction, in that the respective longitudinal axes of symmetry of these partial shells run offset with respect to one another, in such a manner that the adjacent walls of the partial shells form tangential slots or channels in their longitudinal extent for a combustion air flow to flow into the internal area which is formed by the partial shells, and in that the internal area has an internal body whose cross section decreases in the flow direction.
12. Thermal machine according to Claim 11, characterized in that the internal body decreases in a conical shape or quasi-conical shape in the flow direction.
13. Thermal machine according to one of Claims 10-12, characterized in that, in a transitional area between a swirl generator, which belongs to the premixing burner (16), and a downstream mixing tube, transition channels are provided for changing a flow which is formed in the swirl generator to the flow cross section of the mixing tube downstream from the transition channels.
14. Thermal machine according to one of Claims 10-13, characterized in that the number of transitional channels corresponds to the number of partial conical shells or partial shells.

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