Injector for introducing a fuel-air mixture into a combustion chamber

Abstract

An injector (8) for introducing a fuel-air mixture into a combustion chamber: has a longitudinal axis (44) and includes a number of annular curved flow passages. Each flow passage comprises a fuel inlet opening (43), air inlet openings (42) and a fuel-air mixture outlet opening (9). The fuel inlet opening (43) is connected to a fuel distributor (41) and has a central axis (55) which runs perpendicular or parallel to the longitudinal axis (44) of the injector (8). The fuel-air mixture outlet opening (9) has a central axis which runs perpendicular to the longitudinal axis (44) of the injector (8). The air inlet openings (42) each have a central axis (54) which runs parallel to the longitudinal axis (44) of the injector (8).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority of European Patent Application No. EP 13170048, filed May 31, 2013, the contents of which are incorporated by reference herein. The European Patent Application was published in the German language.

FIELD OF THE INVENTION

The present invention relates to an injector for introducing a fuel-air mixture into a combustion chamber, a combustion chamber and a gas turbine.

BACKGROUND OF THE INVENTION

Modern gas turbines are supposed to satisfy, over a wide operating range, the requirements relating to pollutant emissions and environmental concerns. Satisfying these requirements depends substantially on the combustion system used in the gas turbine. In order to reduce emissions of nitrous oxides (NO_x), a lean premix is used. In this context, in order to achieve a high efficiency, high turbine inlet temperatures, which involve high flame temperatures, are targeted. Here, the premix flames mentioned are, on account of the high thermal power density, prone to thermoacoustic instabilities and the NO_x emissions increase exponentially with increasing flame temperature.

On the other hand, it is necessary to operate the gas turbine at loads and flame temperatures which are as low as possible in order to fulfill the requirements of the power station operators. In this context, the emissions of carbon monoxide (CO) produced in the event of incomplete combustion downwardly limit the operating range. For this reason, it is desirable to expand the operating range of the combustion system in both directions.

In order to expand the operating range for existing combustion systems, optimization of the system for current requirements has been undertaken, for example by means of fuel staging inside the burners, efficient premix devices, reduction of cooling air and staged combustion concepts. The staged combustion technology known as “axial staging” consists of a conventional burner which fires a primary combustion zone. This primary zone may in turn feature internal staging, as in conventional burners, and covers the load region up to current firing temperatures. A secondary combustion zone adjoins downstream of the primary zone. In this secondary zone, additional fuel is injected by means of a stage which is offset axially with respect to the primary zone. This fuel is then burnt in a diffusion-type regime. The fuel may be diluted with inert components (steam, nitrogen, carbon dioxide) in order to greatly lower the stoichiometric combustion temperature, and thus suppresses the formation of NO_x. At the same time, distributing the release of heat over all the available combustion space reduces the tendency of the combustion system to thermoacoustic instabilities.

The dilution media required for safe operation within the specified emissions limits must be made available from separate processes, this leading to a number of disadvantages. First, the complexity of the power station as a whole is increased, which translates to higher investment costs. Second, these separate processes, for their part, require energy, which adversely affects the overall degree of efficiency. Third, the availability of the power station is reduced, since these processes present a certain probability of failure which must be added to that of the conventional power station. It is therefore also known to introduce the fuel into the secondary zone in the second axial stage without inert components, in the form of an air-fuel mixture (“fuel only”).

Prior art relating to this and further prior art is described in documents DE 10 2006 053 679 A1 and U.S. Pat. No. 6,418,725 B1, which both relate to tubular combustion chambers, and in documents DE 42 32 383 A1, US 2009/0084082 A1, U.S. Pat. No. 6,192,688 B1, U.S. Pat. No. 6,047,550 and U.S. Pat. No. 6,868,676 B1, which relate to annular combustion chambers.

US 2011/0067402 A1 discloses a gas turbine with a combustion chamber having a two-stage combustion concept. The combustion chamber comprises a combustion chamber head end with a burner arrangement, a combustion chamber outlet and a combustion chamber wall, wherein the combustion chamber wall extends from the combustion chamber head end to the combustion chamber outlet, and a primary zone and a secondary zone. The secondary zone is arranged downstream of the primary zone as seen in the main flow direction of the hot gas. Along the circumference of the combustion chamber there are arranged injectors which open into the secondary zone and which constitute a second axial stage of the combustion system.

DESCRIPTION OF THE INVENTION

The invention is based on the object of providing an injector for introducing a fuel-air mixture into a combustion chamber, a combustion chamber and a gas turbine having at least one such combustion chamber, by means of which a reduction in the emissions of nitrous oxides (NO_x) and low CO emissions may be achieved.

The first object is achieved by an injector herein disclosed, the second object is achieved by a combustion chamber herein disclosed and the third object is achieved by a gas turbine herein disclosed.

The injector according to the invention for introducing a fuel-air mixture into a combustion chamber comprises a longitudinal axis and a number of curved, that is to say not straight, in particular arcuate, flow passages. The expression “arcuate” is in this context to be understood as “curved in the form of at least one arc”, for example also curved like an S. Each flow passage comprises a fuel inlet opening, a number of air inlet openings and a fuel-air mixture outlet opening. In that context, the fuel inlet opening is connected to a fuel distributor. The fuel inlet opening may in addition have a central axis which runs perpendicular or parallel to the longitudinal axis of the injector. The fuel-air mixture outlet opening has a central axis which runs perpendicular to the longitudinal axis of the injector. The air inlet openings have in each case a central axis which runs parallel to the longitudinal axis of the injector.

A fuel-air mixture created in the flow passages may be introduced into a combustion chamber, for example into a secondary stage of a combustion chamber, through the fuel-air mixture outlet openings. By virtue of the bent shape, for example also S shape, of the flow passages, a large mixing length is achieved in a small available space.

Advantageously, the injector may be arranged on the combustion chamber such that its longitudinal axis runs substantially parallel to a longitudinal axis of the combustion chamber. In particular, the longitudinal axis of the injector may coincide with a longitudinal axis of the combustion chamber.

Advantageously, the air inlet openings of a flow passage are arranged in at least one row. In this manner, the fuel introduced into the flow passage through the fuel inlet opening is continuously mixed with the air introduced into the flow passage through the air inlet openings.

The air inlet openings may be of circular cross section. In particular, they may be designed as bores. A row of air inlet openings may preferably run in a spiral shape, for example in a spiral shape with respect to an axis running parallel to the longitudinal axis of the injector. Each flow passage may in particular have a centerline having an at least partially curved or arcuate profile, and the at least one row of the air inlet openings may run parallel to the centerline of the flow passage.

Furthermore, the fuel distributor may be of annular design. The fuel distributor may in particular be arranged, with respect to the longitudinal axis of the injector, radially outside the curved, in particular arcuate, flow passages. Alternatively, the fuel distributor may be arranged, in the axial direction, next to the arcuate flow passages.

The curved, for example arcuate, flow passages may have an angle of curvature that is greater than 0° and less than 180°, for example between 10° and 90°, advantageously between 30° and 60°. In addition, at least one of the curved, in particular arcuate, flow passages may have an axis of curvature which runs parallel to the longitudinal axis of the injector. Preferably, all axes of curvature of the flow passages run parallel to the longitudinal axis of the injector.

The injector may for example comprise two disks which are arranged substantially parallel to one another. In this context, the disks may comprise the sidewalls of the flow passages and the air inlet openings or, in particular, form the sidewalls of the flow passages. In addition, an annular fuel distributor may be securely connected to a combustion chamber, for example to the liner of a combustion chamber or the combustion space wall, by means of the two disks arranged in parallel. The air inlet openings may be arranged in the disks in the form of air bores in a spiral pattern in a plurality of rows. A plurality of sidewalls between the two disks may separate the individual flow passages or mixing passages from one another.

The fuel may be injected into the mixing passages via a plurality of fuel inlet openings, for example in the form of bores, on the inside of the fuel distributor, with respect to the longitudinal axis of the injector. The air may be added to the fuel flow, and mixed therewith, in a perpendicular manner through the air bores arranged in a spiral shape. The fuel-air mixture then passes through a plurality of openings, for example bores, into the combustion space of a combustion chamber, where it is ignited.

The combustion chamber according to the invention comprises at least one injector as described above. The combustion chamber may comprise a longitudinal axis, a combustion chamber head end, a combustion chamber outlet and a combustion chamber wall which extends from the combustion chamber head end to the combustion chamber outlet. It may also comprise a primary zone and a secondary zone, which is arranged downstream of the primary zone in the main flow direction of the hot gas. The at least one injector may be arranged on the combustion chamber wall in the region of the secondary zone such that the fuel-air mixture outlet openings open into the secondary zone. In this context, the injector may serve for introducing a fuel-air mixture into the secondary zone.

The fuel-air mixture outlet openings may be arranged, at a distance from one another, along a circumferential line on the combustion chamber wall.

Furthermore, the combustion chamber may comprise a liner region which comprises the at least one injector. The liner region may adjoin the primary zone in the main flow direction. A transition region to the combustion chamber outlet may adjoin the liner region. The at least one injector may be arranged at the liner region or be designed in one piece with the liner region. In addition, the liner region may comprise a longitudinal axis which coincides with the longitudinal axis of the injector. The longitudinal axis of the injector may also run parallel to the longitudinal axis of the liner region.

The liner region may form just a region of the combustion chamber or be designed as a separate component. It may be arranged between the primary zone and the combustion chamber outlet, for example in the region of the secondary zone.

Preferably, at least one injector according to the invention is arranged on the combustion chamber wall in the region of the secondary zone. The combined injection of air and fuel into the secondary zone produces what is termed an “air-assisted axial stage”.

The combustion chamber may be a tubular combustion chamber or an annular combustion chamber. At least one burner may be arranged at the combustion chamber head end.

Fundamentally, the primary zone is determined as that region in which, inside the combustion chamber, the fuel supplied via the burner is primarily burnt. The secondary zone is distinguished by the fact that the hot gas produced in the primary zone is further combusted, as completely as possible, therein. In this context, the secondary zone may fundamentally be arranged at any position between the primary zone and the combustion chamber outlet.

The air-assisted axial stage per se already has several advantages. By premixing fuel and air outside the combustion space, as in conventional burner technology, the resulting peak temperatures—and therefore the NO_x emissions—can be reduced. Furthermore, lower overall NO_x emissions are obtained by virtue of the shorter residence times in the secondary zone and as far as the turbine inlet. Moreover, no additional media are required; instead operation is carried out using only the air from the compressor outlet which is prepared as a mixture with fuel in the axial stage. The resulting system is therefore obtainable in robust and stable form.

It is further possible, by means of a suitable mode of operation, for the application of fuel to the axial stage to occur only at relatively high loads. At lower loads, the fuel supply to the axial stage is completely shut off and the axial stage then behaves in the manner of an air bypass. As a result, the primary zone may be operated with a high local flame temperature, even at very low loads, which results in a good level of combustion and accordingly low CO emissions. The air-assisted axial stage thus serves, in equal measure, to expand the operating range of the combustion system to lower and higher loads.

The present invention has, in addition, the following special advantages: by virtue of the curved, in particular spiral-shaped, arrangement, a large mixing length can be achieved in the flow passages of the injector in spite of a compact construction. In this manner, a high premix quality is achieved for a small available space. The generation of vortices produces additional gradients and shear layers and thereby improves the mixing with the main flow. By virtue of a more even turbine inlet profile, emissions are reduced. Furthermore, a simple and cost-effective construction of the guide vanes of the first turbine stage (TLe 1) is made possible. Moreover, the present invention presents great potential for savings in cooling air and, where appropriate, potential for savings by omitting the guide vanes of the first turbine stage (TLe 1).

The gas turbine according to the invention comprises a combustion chamber as described above. It has the same properties and advantages as the above-described combustion chamber.

BRIEF DESCRIPTION OF THE FIGURES

Further features, properties and advantages of the present invention will be described in more detail below by way of exemplary embodiments, with reference to the appended figures. The exemplary embodiments do not restrict the scope of protection of the present invention as defined by the patent claims. All described features are in this context advantageous both individually and in any combination with one another.

FIG. 1 shows, by way of example, a partial longitudinal section through a gas turbine;

FIG. 2 shows, schematically, and partially cut away, an annular combustion chamber of a gas turbine;

FIG. 3 shows, schematically, part of a tubular combustion chamber in a partially perspective and partially cutaway view;

FIG. 4 shows a section of the combustion chamber already shown in part in FIG. 3 in a perspective and cutaway view;

FIG. 5 shows, schematically, a perspective view of the liner region with an injector according to the invention;

FIG. 6 shows, schematically, a section through a partial region of an injector according to the invention, in a partially perspective view perpendicular to the longitudinal axis of the injector;

FIG. 7 shows, schematically, a section through a partial region of an injector according to the invention, in a partially perspective view parallel to the longitudinal axis of the injector;

FIG. 8 shows, schematically, a partial region of an alternative design of an injector according to the invention;

FIG. 9 shows, schematically, a section through a partial region of an injector according to the invention, perpendicular to the longitudinal axis of the injector.

DESCRIPTION OF EMBODIMENTS

FIG. 1 shows, by way of example, a partial longitudinal section through a gas turbine 100. In the interior, the gas turbine 100 has a rotor 103 with a shaft 101 which is mounted such that it can rotate about an axis of rotation 102 and is also referred to as the turbine rotor.

An intake housing 104, a compressor 105, a, for example, toroidal combustion chamber 110, in particular an annular combustion chamber, with a plurality of coaxially arranged burners 107, a turbine 108 and the exhaust-gas housing 109 follow one another along the rotor 103.

The combustion chamber 110 is in communication with a, for example, annular hot-gas passage 111, where, by way of example, four successive turbine stages 112 form the turbine 108.

Each turbine stage 112 is formed, for example, from two blade or vane rings. As seen in the direction of flow of a working medium 113, in the hot-gas passage 111 a row of guide vanes 115 is followed by a row 125 formed from rotor blades 120.

The guide vanes 130 are secured to an inner housing 138 of a stator 143, whereas the rotor blades 120 of a row 125 are fitted to the rotor 103 for example by means of a turbine disk 133.

A generator (not shown) is coupled to the rotor 103.

While the gas turbine 100 is operating, the compressor 105 sucks in air 135 through the intake housing 104 and compresses it. The compressed air provided at the turbine-side end of the compressor 105 is passed to the burners 107, where it is mixed with a fuel. The mix is then burnt in the combustion chamber 110, forming the working medium 113. From there, the working medium 113 flows along the hot-gas passage 111 past the guide vanes 130 and the rotor blades 120. The working medium 113 is expanded at the rotor blades 120, transferring its momentum, so that the rotor blades 120 drive the rotor 103 and the latter in turn drives the generator coupled to it.

While the gas turbine 100 is operating, the components which are exposed to the hot working medium 113 are subject to thermal stresses. The guide vanes 130 and rotor blades 120 of the first turbine stage 112, as seen in the direction of flow of the working medium 113, together with the heat shield elements which line the annular combustion chamber 110, are subject to the highest thermal stresses.

To be able to withstand the temperatures which prevail there, they may be cooled by means of a coolant.

By way of example, iron-based, nickel-based or cobalt-based superalloys are used as material for the components, in particular for the turbine blades or vanes 120, 130 and components of the combustion chamber 110.

The guide vane 130 has a guide vane root (not shown here), which faces the inner housing 138 of the turbine 108, and a guide vane head which is at the opposite end from the guide vane root. The guide vane head faces the rotor 103 and is fixed to a securing ring 140 of the stator 143.

FIG. 2 shows, schematically, a combustion chamber 110 of a gas turbine. The combustion chamber 110 shown is designed as what is known as an annular combustion chamber, in which a multiplicity of burners 107, which generate flames and are arranged circumferentially around a longitudinal axis of the combustion chamber 102, open into a common combustion chamber space 154. For this purpose, the combustion chamber 110 overall is of annular design positioned around the longitudinal axis 102.

To achieve a relatively high efficiency, the combustion chamber 110 is designed for a relatively high temperature of the working medium M of approximately 1000° C. to 1600° C. To allow a relatively long service life even with these operating parameters, which are unfavorable for the materials, the combustion chamber wall 153 is provided, on its side which faces the working medium M, with an inner lining formed from heat shield elements 155.

FIG. 3 shows, schematically, part of a combustion chamber in a partially perspective and partially cutaway view. The combustion chamber comprises a combustion chamber wall 1 and a combustion chamber outlet 6. The main flow direction of the hot gas inside the combustion chamber, when the combustion chamber is in operation, is indicated by an arrow 3.

The combustion chamber further comprises a primary zone 4 in which the fuel introduced into the combustion chamber from the burner is burnt. A secondary zone 5 adjoins the primary zone in the flow direction 3. The hot gas from the primary zone 4 is further burnt off in the secondary zone 5. This occurs by means of the additional introduction of a fuel-air mixture 14 into the secondary zone 5 with the aid of injectors 8.

The injectors 8 comprise an air supply 13 and an outlet 9 which opens into the combustion chamber. Furthermore, a fuel nozzle 10 is arranged inside each injector 8. The fuel nozzle 10 is connected to a fuel distributor 11, preferably an annular fuel distributor 11. With the aid of the fuel nozzle 10, fuel is injected into the interior of the injector 8 and thus a fuel-air mixture is produced inside the injector 8. The fuel-air mixture produced in this manner is then injected into the combustion chamber, in the region of the secondary zone 5, through the injector outlet or the injection opening 9.

In FIG. 3, a liner region 7 and a transition region 25, which in FIG. 3 are in each case designed as separate components, are arranged between the primary zone 4 and the combustion chamber outlet 6. At least one sealing ring 12 is arranged between the primary zone 4 and the liner region 7. Furthermore, at least one sealing ring 12 is also arranged between the liner region 7 and the transition component 25. The injectors 8 are connected to the liner region 7. The injector outlets or injection openings 9 open into the secondary zone 5 of the combustion chamber in the region of the liner region 7.

FIG. 4 shows a section of the combustion chamber already shown in part in FIG. 3 in a perspective and cutaway view. In addition to the components already shown in FIG. 3 and described in that context, FIG. 4 shows a fuel supply 15 which supplies fuel to the fuel distributor 11.

FIG. 5 shows, schematically, a perspective view of the liner region with an injector 28, in the following referred to as a spiral injector, according to the invention. The liner region 7 comprises an outer surface 32 on which the spiral injector 28 is arranged.

The spiral injector 28 comprises outlet openings 9 through which the fuel-air mixture produced inside the spiral injector 28 is fed into the interior of the combustion chamber. In the exemplary embodiment shown in FIG. 5, the outlet openings 9 are of rectangular, for example square, shape. Alternatively, they may also be of circular cross section.

The spiral injector 28 comprises an annular fuel distributor 41 which is arranged about the outer surface 32 of the liner region 7. In the embodiment variant shown here, the annular fuel distributor 41 forms, at the same time, that region of the spiral injector 28 which is arranged radially outwards with respect to the longitudinal axis or central axis 44 of the liner region 7. The central axis or longitudinal axis 44 of the liner region 7 corresponds in this context to the central axis or longitudinal axis of the injector 28 according to the invention.

The annular fuel distributor 41 comprises at least one fuel supply 45. FIG. 5 shows two fuel supply devices 45 arranged opposite one another with respect to the longitudinal axis 44 of the injector.

The spiral injector 28 further comprises flow passages or injector passages 48 arranged between the fuel distributor 41 and the outer surface 32 (see FIGS. 6 and 7). The injector passages 48 are in this context arranged in a disk-shaped region which connects the outer surface 32 of the liner region 7 to the annular fuel distributor 41. The outer surface 50 of the spiral injector 28 located between the annular fuel distributor 41 and the liner region 7 comprises a number of air bores 42.

The air bores 42 are preferably provided on both sides of the spiral injector, that is to say on the upstream and downstream surface 50, with respect to the main flow direction 3. The air bores 42 are arranged next to one another in individual rows. Each air bore row is assigned to an injector passage 48. The shape of the respective injector passage 48 and, accordingly, of the respective air bore row is bent, preferably spiral-shaped, toward the central axis 44.

The air inlet openings or air bores 42 have in each case a central axis 54 which runs parallel to the longitudinal axis 44 of the injector.

FIGS. 6 and 7 show in each case sections through partial regions of a spiral injector 28 according to the invention, in a partially perspective view. Here, the section shown in figure runs perpendicular to the longitudinal axis 44 of the injector and the section shown in FIG. 7 runs parallel to the longitudinal axis 44.

The fuel which is fed through the annular fuel distributor 41 to the injector passages 48 is introduced into the injector passages 48 in the flow direction 46. At the same time, air is supplied to the injector passages 48 via the air bores 42. A fuel-air mixture is thereby produced inside the injector passages 48 and is subsequently introduced into the combustion chamber through the outlet openings 9. The individual injector passages 48 are delimited from one another by means of sidewalls 49.

The spiral injector 28 is installed perpendicular to the liner region 7, that is to say perpendicular to the central axis 44 of the liner region 7, wherein the longitudinal axis 44 of the injector, which can also be labeled as the central axis 44 of the injector, coincides, in the exemplary embodiment represented, with the central axis of the liner. The annular fuel distributor 41 is for example securely attached to the liner region 7 by means of two disks arranged in parallel. In these disks, the air bores 42 are arranged in a spiral or arcuate shape in a plurality of rows. A plurality of sidewalls 49 between the two disks separate different mixing passages or injector passages 48 from one another. The fuel is injected into the mixing passages 48 through a plurality of openings, for example bores 43, on the inside of the fuel distributor 41. The air is added to the fuel flow 46, and mixed therewith, in a perpendicular manner through the air bores 42 arranged in a spiral shape. The fuel-air mixture then passes through a plurality of openings 9, for example bores, in the liner region 7 into the combustion space, where it is ignited.

The fuel inlet openings 43 have in each case a central axis 55 which runs perpendicular, in particular tangentially, to the central axis 44 of the injector.

FIG. 8 shows a further variant embodiment, in which, as seen in relation to the longitudinal axis 44 of the injector 8, the fuel distributor 41 is arranged next to the arcuate flow passages 48 in the axial direction. The flow direction of the fuel is labeled with the reference numeral 51. The flow direction of the air is labeled with the reference numeral 52.

FIG. 9 shows, schematically, a section through a partial region of an injector according to the invention, perpendicular to the central axis. In the variant embodiment shown in FIG. 9, in contrast to the previously described variant embodiments, the injector passages 48 are configured in an S shape. In addition, the air inlet openings 42 are arranged in an S shape.

Claims

1. An injector for introducing a fuel-air mixture into a combustion chamber, the injector comprising:

a longitudinal axis of the injector;

a plurality of curved flow passages, each flow passage comprising a fuel inlet opening, a plurality of air inlet openings and a fuel-air mixture outlet opening;

a fuel distributor to which the fuel inlet opening is connected;

each fuel-air mixture outlet opening of each curved flow passage has a central axis which runs perpendicular to the longitudinal axis of the injector; and

each air inlet opening of each curved flow passage has a central axis which runs parallel to the longitudinal axis of the injector.

2. In combustion the injector as claimed in claim 1, and a combustion chamber with a combustion chamber wall wherein the injector is arranged on the combustion chamber wall such that the longitudinal axis of the injector runs substantially parallel to or coincides with;

a longitudinal axis of the combustion chamber.

3. The injector as claimed in claim 1, further comprising the air inlet openings of at least one of the flow passage are arranged in at least one row.

4. The injector as claimed in claim 1, wherein the fuel distributor is of annular design.

5. The injector (8) as claimed in claim 4, wherein with respect to the longitudinal axis of the injector, the fuel distributor is arranged radially outside the curved flow passages or is arranged, in next to the curved flow passages the axial direction.

6. The injector as claimed in claim 1, wherein the curved flow passages have an angle of curvature that is greater than 0° and less than 180°.

7. The injector as claimed in claim 1, wherein at least one of the curved flow passages has an axis of curvature which runs parallel to the longitudinal axis of the injector.

8. The injector as claimed in claim 1, wherein the injector comprises two disks which are arranged substantially parallel to one another, in the combustion chamber and the disks comprise sidewalls of the flow passages and the air inlet openings.

9. A combustion chamber which comprises at least one of the injectors as claimed in claim 1.

10. The combustion chamber as claimed in claim 9, wherein the combustion chamber further comprises a longitudinal axis, a combustion chamber head end, and a combustion chamber outlet, a combustion chamber wall which extends from the combustion chamber head end to the combustion chamber outlet, a primary zone in the combustion chamber and a secondary zone, which is arranged in the combustion chamber downstream of the primary zone in a main flow direction of the hot gas, and the at least one injector is arranged on the combustion chamber wall at a location and are configured such that the fuel-air mixture outlet openings open into the secondary zone.

11. The combustion chamber as claimed in claim 9, wherein the fuel-air mixture outlet openings are arranged along a circumferential line on the combustion chamber wall.

12. The combustion chamber as claimed in claim 9, further comprising the combustion chamber comprises a liner region which comprises the at least one injector.

13. The combustion chamber as claimed in claim 12, wherein the liner region has a longitudinal axis which coincides with the longitudinal axis of the injector.

14. The combustion chamber as claimed in claim 12, wherein the liner region is a discrete component of the chamber wall.

15. The combustion chamber as claimed in claim 9, wherein the combustion chamber is an annular combustion chamber or as a tubular combustion chamber.

16. A gas turbine which comprises a combustion chamber as claimed in claim 10.