Hybrid fuel gas turbine engine, control method therefor, and combustor therefor

Abstract

A gas turbine engine comprises a compressor (2), a combustor (3), a turbine (5), a primary supply system (6) to supply a primary fuel (F1) comprising ammonia, a secondary supply system (7) to supply a secondary stream (F2) comprising air and / or fuel, and a control system (8). The combustor includes a combustion chamber (12), a plurality of burner assemblies (10) each having a respective reaction zone (Zt) inside the combustion chamber, and a plurality of injectors (11) configured to inject a secondary fluid downstream of the reaction zones of the burner assemblies. The control system is configured to: control the primary supply system such that the burner assembly converts a first mixture having a first fuel-to-air equivalence ratio ([phi] 1) greater than 1 in the reaction zone; and controlling the primary supply system such that the injector injects the secondary fluid into the combustion chamber at a second fuel-to-air equivalence ratio ([phi] 2) of less than 1.

Description

[0001] Cross-reference to related applications This patent application claims priority to Italian Patent Application No. 102024000023052, filed on October 16, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present invention relates to a mixed-fuel gas turbine engine, a method for controlling a mixed-fuel gas turbine engine, and a combustor for a mixed-fuel gas turbine engine. Background Technology

[0003] As is known, ammonia is a promising fuel that can be used to power gas turbine engines and make a significant contribution to decarbonization. On the one hand, the combustion of ammonia is virtually carbon-free, and on the other hand, ammonia is a suitable fuel for the efficient and long-term storage of large amounts of chemical energy. For example, the required volume can be significantly reduced compared to hydrogen because ammonia is quite readily liquefied and can be maintained in a liquid state even at room temperature and relatively low pressure. In this way, not only is storage efficient, safe, and economical, but transportation and distribution are also efficient, safe, and economical.

[0004] However, it is known that under normal operating conditions of a gas turbine engine, especially in lean premixed mode, the combustion of ammonia produces significant amounts of nitrogen oxides (NOx). NOx emissions are critical and must be minimized, just as carbon monoxide emissions must be minimized. Therefore, when directly supplied to a gas turbine engine, a mixture of ammonia and carbon-based fuels (such as natural gas or methane) may not meet current stringent NOx emission requirements. Consequently, the advantages of zero-carbon or at least low-carbon combustion can be offset by a corresponding increase in NOx emissions.

[0005] On the other hand, there is evidence that using a rich mixture with a fuel / air equivalence ratio greater than 1 could be a solution to the NOx emission problem from ammonia combustion, but would require a completely new combustion system.

[0006] In addition, ammonia has relatively low reactivity, which is another obstacle that makes it difficult to use it alone as a fuel or mixed with other components in gas turbine engines.

[0007] In other words, gas turbine engines are generally incompatible with the supply of ammonia, either as the sole fuel or as a component of a natural gas mixture. Summary of the Invention

[0008] Therefore, the object of the present invention is to provide a gas turbine engine, a method for controlling a gas turbine engine, and a combustor for a gas turbine engine, which allows overcoming or at least mitigating the described limitations.

[0009] According to one aspect of the present invention, a gas turbine engine is provided, comprising: Compressor, burner, and turbine; The primary supply system supplies primary fuels containing ammonia; Secondary supply systems, whose supply includes secondary streams of air and / or fuel; and Control system; The burner includes a combustion chamber, multiple burner assemblies, and multiple injectors. Each burner assembly has a corresponding reaction zone inside the combustion chamber, and the injectors are configured to inject secondary fluid downstream of the reaction zone of each burner assembly. The control system is configured to: control the primary supply system such that the burner assembly converts a first mixture having a first fuel-air equivalence ratio greater than 1 in the first reaction zone; and control the secondary supply system such that the injector injects secondary fluid into the combustion chamber at a second fuel-air equivalence ratio less than 1.

[0010] In this manner, within the reaction zone of the burner assembly, given a first fuel-air equivalence ratio, a mixture containing primary fuel (i.e., ammonia) undergoes thermochemical decomposition in the absence of oxygen. In practice, the first burner functions as an ammonia cracker, and the highly reactive molecular hydrogen products of the decomposition are subsequently ignited as a result of excess oxygen combustion following the injection of a secondary fluid at a second fuel-air equivalence ratio of less than 1. The secondary fluid can be air or a secondary fuel, such as: highly reactive fuels, particularly those with high hydrogen content, such as ammonia; mixtures of nitrogen and hydrogen, or mixtures of ammonia and hydrogen, or mixtures of ammonia, nitrogen, and hydrogen; fuel gases, such as natural gas or syngas; or mixtures of nitrogen, hydrogen, and fuel gases; or mixtures thereof. The combustion of molecular hydrogen substantially depletes or otherwise reduces oxygen availability within a short time and prevents the formation of excess nitrogen oxides. Therefore, this control allows for the use of ammonia as fuel while maintaining compliance with regulations regarding pollution emissions.

[0011] Furthermore, this invention can be integrated into existing gas turbine engines without substantial modifications. On the one hand, the machine design can be easily adapted to allow operation using ammonia. On the other hand, even existing gas turbine engines can be modified through retrofitting to be compatible with the use of ammonia as fuel.

[0012] According to another aspect of the invention, the first fuel-air equivalence ratio is between 1 and 1.5.

[0013] The range of the first fuel-air equivalence ratio ensures both low nitrogen oxide emissions and the conditions for the thermochemical decomposition of primary fuels.

[0014] According to another aspect of the invention, the second fuel-air equivalence ratio is less than 0.4.

[0015] According to another aspect of the invention, the combustion chamber is annular in shape and has connecting walls, and wherein each burner assembly includes a first burner and a second burner, the first burner and the second burner defining a first portion and a second portion of a respective reaction zone, and are arranged coaxially along the axis of the respective burner assembly, wherein the first burner surrounds the second burner and the first portion of the reaction zone is radially outside the second portion.

[0016] In addition to generally benefiting the use of ammonia as a fuel and improving emissions, the present invention also allows for sequential combustion schemes in practice, even in burner types where combustion typically occurs in a single stage, to improve efficiency and further improve emissions control.

[0017] According to another aspect of the invention, each injector has a plurality of nozzles arranged such that secondary fluid is injected downstream of the reaction zone of a correspondingly adjacent injector assembly.

[0018] Injection downstream of the burner assembly's reaction zone ensures that the secondary fluid interacts with the combustion products of the burner assembly after ammonia decomposition without premature interference.

[0019] According to another aspect of the invention, the burner assembly is in communication with the combustion chamber via a connecting wall, and wherein each injector includes a corresponding tubular body extending from the connecting wall along the injector axis toward the interior of the combustion chamber.

[0020] This structure defines a simple and effective way to bring secondary fluids downstream of the burner's reaction zone.

[0021] According to another aspect of the invention, the injector includes a corresponding elongated body having a trailing edge and extending transversely to the gas flow passing through the combustion chamber from the inner shell of the combustion chamber to the outer shell.

[0022] An injector in the form of a slender body transverse to the gas flow passing through it allows the advantages associated with reduced pollution emissions to be maintained without necessarily occupying space between the burner components. Therefore, this space is available and can be used according to design preferences, such as to accommodate an acoustic damper.

[0023] According to another aspect of the invention, the trailing edge of the injector has a convex angle.

[0024] The presence of convex angles facilitates airflow mixing and improves combustion efficiency.

[0025] According to another aspect of the present invention, a method for controlling a gas turbine engine is provided, wherein the gas turbine engine comprises: Compressors, burners, and turbines; and Primary supply system; Secondary supply systems, whose supply includes secondary streams of air and / or fuel; and Control system; The burner includes a combustion chamber, multiple burner assemblies, and multiple injectors. Each burner assembly has a corresponding reaction zone inside the combustion chamber, and the multiple injectors are configured to inject secondary fluid downstream of the reaction zone of the burner assembly. The method includes: Primary fuel is supplied to the burner assembly and secondary fluid is supplied to the injector, wherein the primary fuel comprises ammonia and the secondary fluid comprises air and / or fuel; and The primary supply system is controlled such that the burner assembly converts a first mixture having a first fuel-air equivalence ratio greater than 1 in the reaction zone, and the secondary fluid has a second fuel-air equivalence ratio less than 1 in the second reaction zone.

[0026] According to another aspect of the present invention, a combustor for a gas turbine engine is provided, comprising: Combustion chamber; Multiple burner assemblies, each operable with a primary fuel containing ammonia, and each having a corresponding reaction zone within a combustion chamber; and Multiple injectors configured to inject secondary fluid downstream of the reaction zone of the burner assembly The combustion chamber is annular and has connecting walls, and each burner assembly includes a first burner and a second burner, the first burner and the second burner defining a first part and a second part of a corresponding reaction zone, and are arranged coaxially along the axis of the corresponding burner assembly, wherein the first burner surrounds the second burner and the first part of the reaction zone is radially outside the second part. Attached Figure Description

[0027] To better understand the invention, preferred embodiments will now be described with reference to the accompanying drawings for illustrative and non-limiting purposes only, in which: - Figure 1 This is a simplified block diagram of a gas turbine engine according to an embodiment of the present invention; - Figure 2 The present invention illustrates an embodiment in Figure 1The axial cross-section of components used in gas turbine engines; - Figure 3 yes Figure 2 A schematic front view of the components; - Figure 4 yes Figure 2 The axial cross-section of the component with magnified details; - Figure 5 Show Figure 3 Zoom in on the details of the view; - Figure 6 Different embodiments of the present invention are shown. Figure 3 Zoom in on the details of the view; - Figure 7 These are different embodiments of the present invention. Figure 2 A magnified axial cross-section of a component part; - Figure 8 The illustration shows another embodiment of the invention. Figure 1 The axial cross-section of components used in gas turbine engines; - Figure 9 yes Figure 8 A schematic front view of a component; and - Figure 10 This is according to another embodiment of the present invention. Figure 8 A schematic front view of a component. Detailed Implementation

[0028] Reference Figure 1 The gas turbine engine as a whole is identified by the number 1 and includes a compressor 2, a burner 3, a turbine 5, a primary supply system 6, a secondary supply system 7, and a control system 8.

[0029] Compressor 2 and turbine 5 are mounted on the same shaft, which extends along the main axis A.

[0030] In the embodiments described herein, the burner 3 is of annular type and is arranged around the main axis A between the compressor 2 and the turbine 5. However, this should not be considered limiting, as the invention can also be advantageously used with combustion chambers of different types, particularly silo-type combustion chambers.

[0031] The burner 3 includes multiple burner assemblies 10 and multiple injectors 11, as well as an annular combustion chamber 12, such as Figure 2As shown herein, the burner assemblies 10 and injectors 11 are circumferentially distributed around axis A and alternate in the embodiment shown herein. Thus, in this case, each burner assembly 10 has two adjacent injectors 11. The burner assemblies 10 are mounted in corresponding burner seats in the connecting wall 12a of the combustion chamber 12 via corresponding burner inserts 13.

[0032] Primary Supply System 6 ( Figure 1 It is configured to supply ammonia (NH3) gas to burner 3 as primary fuel F1.

[0033] The secondary supply system 7 is configured to additionally supply secondary fluid F2 to the burner 3. The secondary fluid F2 may be air or a secondary fuel, such as: highly reactive fuels, especially fuels with high hydrogen content, such as ammonia; mixtures of nitrogen and hydrogen; fuel gases, such as natural gas or syngas; or mixtures of nitrogen, hydrogen and fuel gases.

[0034] The primary supply system 6 and the secondary supply system 7 may share a gas chamber (not shown) surrounding the combustion chamber 3 to supply airflow to the burner assembly 10 and the injector 11.

[0035] The control system 8 defines a load setpoint for the gas turbine engine 1 and drives the engine actuators (the inlet guide vane 2a of the compressor 2 and control valves 6a, 6a' for primary fuel F1 and control valve 6b for secondary fluid F2) to supply air and fuel to the combustor 3 to meet the load setpoint. Specifically, to exclusively supply air as secondary fluid F2 to the injector 11, the control system 8 can close valve 6b and interrupt fuel delivery to the injector 11.

[0036] Figure 3 and Figure 4 A portion of the combustion chamber 12 is shown in detail, including one of the burner assemblies 10 and one of the adjacent injectors 11. The burner assembly 10 extends along the burner axis B and includes a peripheral or diagonal burner 15 and an axial burner 16 arranged coaxially around the burner axis B, wherein the peripheral burner 15 is arranged around the axial burner 16.

[0037] The peripheral burner 15 is of a premixed type, arranged around the axial burner 16 and communicating with the combustion chamber 12 via a corresponding burner insert 13. More specifically, the peripheral burner 15 extends through an opening in the connecting wall 12a such that the outlet of the peripheral burner 15 is inside the combustion chamber 12.

[0038] The peripheral burner 15 is arranged around the axial burner 16 and is provided with means for generating vortices or turbulence, referred to as a diagonal vortex and indicated by reference numeral 20. The diagonal vortex 20 extends about the burner axis B and is radially defined between the inner truncated cone body 21 and the outer truncated cone body 22 of the peripheral burner 15. In one embodiment, the inner truncated cone body 21 may be a monolithic body, manufactured, for example, by an additive manufacturing process such as SLM (Selective Laser Melting). The outer truncated cone body 22 is axially hollow and includes a truncated cone wall 22a, and in one embodiment includes an end portion 22b, which is, for example, cylindrical and connected to the truncated cone wall 22a via a connecting portion 22c. The truncated cone wall 22a coaxially accommodates the inner truncated cone body 21, such that a substantially annular space 23 is defined between the outer truncated cone body 22 and the inner truncated cone body 21, constituting a passage for supplying an air-fuel mixture.

[0039] The peripheral burner 15 is configured to define a generally annular, potentially divergent peripheral reaction zone Zp around the burner axis B.

[0040] The axial burner 16 includes an axial swirler 25, which is partially housed inside the inner truncated cone body 21 and protrudes axially continuously from the surface of the inner truncated cone body 21.

[0041] The axial burner 16 is configured to define an axial reaction zone Za along the burner axis B, which is radially inward of the peripheral reaction zone Zp. More precisely, the axial reaction zone Za and the peripheral reaction zone Zp are coaxial and symmetrical about the burner axis B. The axial reaction zone Za is defined immediately downstream of the axial burner 16 and may be partially contained in the end portion of the peripheral burner 15, particularly in the end portion 22b. The peripheral reaction zone Zp is defined substantially downstream of the outer truncated cone body 22 and may be retracted in the axial direction until the peripheral reaction zone Zp is partially contained in the end portion of the peripheral burner 15 (e.g., depending on operating conditions). The peripheral reaction zone Zp extends partially around the axial reaction zone Za and may overlap. Together, the peripheral reaction zone Zp and the axial reaction zone Za define the total reaction zone Zt of the burner assembly 10.

[0042] exist Figure 3 In the embodiment, both the peripheral burner 15 and the axial burner 16 receive primary fuel F1, i.e., ammonia, from the primary supply system 6.

[0043] Each injector 11 includes a corresponding tubular body 11a (e.g., cylindrical) extending from the connecting wall 12a along the injector axis C toward the interior of the combustion chamber 12. In one embodiment, the injector axis C is perpendicular to the connecting wall 12a. A first end of the injector 11 is fixed to the connecting wall 12a and is open to receive secondary fluid F2 through the connecting wall 12a itself, while the second end is blind. More precisely, depending on the composition, the secondary fluid F2 can be supplied through a central cavity or channel (not shown) of the tubular body 11a.

[0044] At the second end, the injector 11 is provided with nozzles 30, which are circumferentially arranged and configured to inject secondary fluid F2 transversely to the injector axis C (e.g., in the vertical direction). The nozzles 30 are not necessarily uniformly spaced in the circumferential direction. Figure 5 Instead, they can be distributed differently depending on design preferences. For example, nozzles 30 may be closer together near adjacent burner assemblies 10, and more spaced out or absent elsewhere, such as in... Figure 6 As in the example. Nozzle 30 does not necessarily need to be configured to inject fuel perpendicular to the injector axis C. In Figure 7 In some embodiments, for example, nozzle 30 is configured to inject vertically and partially configured to inject at an angle less than 90° relative to the injector axis C. Additionally, some of the nozzles 30 may be arranged at the ends of the injector 11 and deliver fuel in a direction parallel to the injector axis C. However, it is understood that... Figures 4 to 7 The configuration is provided only as a non-limiting embodiment, and the number, arrangement, position and spray angle of the nozzles 30 can be flexibly selected based on design preferences.

[0045] Furthermore, the nozzle 30 is arranged relative to the injector axis C such that the injection of secondary fluid F2 occurs downstream of the correspondingly adjacent burner assembly 10 reaction zone Zt, without substantially interfering with the combustion of primary fuel F1 in the reaction zone Zt itself. In practice, the injection of secondary fluid F2 occurs when the combustion reaction of the burner assembly 10 is actually exhausted.

[0046] The control system 8 acts on control valves 6a, 6a', and 6b (and on the inlet guide vanes of compressor 2) to alternately or simultaneously supply a mixture of air and primary fuel F1 with a controlled fuel-air equivalence ratio to the axial burner 16 and the peripheral burner 15.

[0047] The fuel-air equivalence ratio of the mixture is limited to: Where, m F It is the fuel flow rate of the mixture, m A It is the air flow rate of the mixture, and (m F / m A ) ST It is the ratio between the fuel flow rate and the air flow rate under stoichiometric conditions.

[0048] The peripheral burner 15 and the axial burner 16 receive a mixture having a first fuel-air equivalence ratio φ1 greater than 1, which is converted in the axial reaction zone Za. More precisely, the first fuel-air equivalence ratio φ1 is between 1 and 1.5, and in this way, ammonia in the primary fuel F1 is decomposed into molecular hydrogen and molecular nitrogen in the reaction zone Zt of the burner assembly 10 by anaerobic thermochemical decomposition (pyrolysis).

[0049] Injector 11 receives secondary fluid F2 from secondary supply system 7 and injects it downstream of reaction zone Zt of burner assembly 10 through nozzle 30. Secondary fluid F2 has a second fuel-air equivalence ratio φ2 significantly lower than 1. For example, the second fuel-air equivalence ratio φ2 is lower than 0.4. Specifically, as already mentioned, secondary fluid F2 can be air (φ2=0) or a fuel with high hydrogen content (such as ammonia), a mixture of nitrogen and hydrogen, fuel gas, or a mixture of nitrogen, hydrogen, and fuel gas. In these cases, control system 8 controls the second fuel-air equivalence ratio φ2 to obtain a desired value.

[0050] In practice, the burner assembly 10 (or one separately between the peripheral burner 15 and the axial burner 16) serves as an ammonia cracker, and the highly reactive molecular hydrogen produced by the decomposition is subsequently ignited by the combustion of excess oxygen from the secondary fluid F2 supplied by the injector 11 downstream of the peripheral reaction zone Zp. The combustion of the molecular hydrogen essentially depletes or otherwise reduces oxygen availability and decreases the formation of nitrogen oxides within a short period of time.

[0051] according to Figure 8 and Figure 9 The different embodiments of the invention shown, wherein components identical to those already described are designated by the same reference numerals, include injectors (denoted herein as 111) comprising a corresponding elongated body 111a, preferably an aerodynamic body having a leading edge 111b and a trailing edge 111c, extending transversely to the combustion chamber 12 and substantially perpendicular to the gas flow direction. More specifically, each injector 111 has a first end and a second end respectively fixed to the inner shell 12b and outer shell 12c of the combustion chamber 12. Fixing can be achieved by thermally insulating tiles 112 forming a thermal shield for the combustion chamber 12. The injector 111 may receive secondary fluid F2, for example, by being fixed to the outer shell 12c.

[0052] In the circumferential direction, the injector 111 alternates with the burner assembly 10.

[0053] Each injector 111 is provided with a nozzle 130, which is arranged, for example, along the trailing edge 111c and configured to inject secondary fluid F2 laterally and / or in the same direction relative to the flow of gas in the combustion chamber 12. The nozzles 130 are not necessarily uniformly spaced along the trailing edge 111c, but may be distributed differently according to design preferences.

[0054] Furthermore, relative to the direction of gas flow, the nozzle 130 is arranged such that the injection of the secondary fluid F2 occurs downstream of the corresponding adjacent burner assembly 10 reaction zone Zt, without substantially interfering with the combustion of the primary fuel F1 in the reaction zone Zt itself.

[0055] In one embodiment ( Figure 10 In the process, the trailing edge 111c of the injector 111 may have a convex angle to facilitate mixing.

[0056] As in Figures 2 to 6 As in the embodiment, the first fuel-air equivalence ratio φ1 is between 1 and 1.5, while the second fuel-air equivalence ratio φ2 is much lower than 1. If the secondary fluid F2 is only air, the second fuel-air equivalence ratio φ2 may be zero.

[0057] Despite their different constructions, the same type of reaction described above occurs, which is essentially determined by the value of the fuel-air equivalence ratio. Ammonia is thermally decomposed into molecular hydrogen and oxygen-deficient molecular nitrogen (this time in the peripheral reaction zone), and the molecular hydrogen is subsequently ignited by a burner in the axial reaction zone through excess oxygen in the secondary fluid.

[0058] Finally, it is clear that modifications and alterations may be made to the gas turbine engine, method, and injector assembly described and shown herein without departing from the scope of the invention as defined in the appended claims.

Claims

1. A gas turbine engine, comprising: Compressor (2), burner (3) and turbine (5); Primary supply system (6), which supplies primary fuel (F1) containing ammonia; The secondary supply system (7) supplies a secondary stream (F2) of air and / or fuel; and Control system (8); The burner (3) includes a combustion chamber (12), a plurality of burner assemblies (10), and a plurality of injectors (11; 111). Each of the plurality of burner assemblies has a corresponding reaction zone (Zt) within the combustion chamber (12), and the plurality of injectors are configured to inject the secondary fluid (F2) downstream of the reaction zone (Zt) of the burner assembly (10). The control system (8) is configured to: control the primary supply system (6) such that the burner assembly (10) converts a first mixture having a first fuel-air equivalence ratio (φ1) greater than 1 in the reaction zone (Zt); and control the secondary supply system (7) such that the injectors (11; 111) inject the secondary fluid (F2) into the combustion chamber (12) at a second fuel-air equivalence ratio (φ2) less than 1.

2. The gas turbine engine of claim 1, wherein, The first fuel-air equivalence ratio (φ1) is between 1 and 1.

5.

3. The gas turbine engine of claim 1, wherein, The second fuel-air equivalence ratio (φ2) is less than 0.

4.

4. The gas turbine engine of claim 1, wherein, The combustion chamber (12) is annular and has a connecting wall (12a), and each burner assembly (10) includes a first burner (15) and a second burner (16), the first burner (15) and the second burner (16) defining a first portion (Zp) and a second portion (Za) of the respective reaction zone (Zt) and arranged coaxially along the axis (B) of the respective burner assembly (10), wherein the first burner (15) surrounds the second burner (16) and the first portion (Zp) of the reaction zone (Zt) is radially outside the second portion (Za).

5. The gas turbine engine according to claim 4, wherein, The injectors (11; 111) and the burner assembly (10) alternate in the circumferential direction of the combustion chamber (12).

6. The gas turbine engine according to claim 5, wherein, Each injector (11; 111) has a plurality of nozzles (30; 130) arranged such that the secondary fluid (F2) is injected downstream of the reaction zone (Zt) of the correspondingly adjacent burner assembly (10).

7. The gas turbine engine according to claim 4, wherein, The burner assembly (10) is in communication with the combustion chamber (12) via the connecting wall (12a), and wherein each injector (11) includes a corresponding tubular body (11a) extending from the connecting wall (12a) along the injector axis (C) toward the interior of the combustion chamber (12).

8. The gas turbine engine according to claim 7, wherein, Each of the injectors (11) has a first end and a second end, the first end being fixed to the connecting wall (12a) and open to receive the secondary fluid (F2), and wherein the nozzle (30) is circumferentially arranged at the second end and configured to inject the secondary fluid (F2) laterally and / or in a direction parallel to the injector axis (C).

9. The gas turbine engine according to claim 4, wherein, The injector (111) includes a corresponding elongated body (111a) having a trailing edge (111c) and extending transversely to the gas flow passing through the combustion chamber (12) from the inner shell (12b) of the combustion chamber (12) to the outer shell (12c).

10. The gas turbine engine according to claim 9, wherein, The nozzle (130) is disposed at the trailing edge (111c) and configured to inject the secondary fluid (F2) laterally and / or in a direction parallel to the gas flow in the combustion chamber (12).

11. The gas turbine engine according to claim 9, wherein, The trailing edge (111c) of the injector (111) has a convex angle.

12. The gas turbine engine according to claim 4, wherein, Each burner assembly (10) includes an inner truncated cone body (21) and an outer truncated cone body (22), wherein the first burner (15) includes a diagonal vortex (20) defined internally by the inner truncated cone body (21) and externally by the outer truncated cone body (22), and the second burner (16) includes an axial vortex (25) housed in the inner truncated cone body (21).

13. A method for controlling a gas turbine engine, wherein, The gas turbine engine includes: Compressor (2), burner (3) and turbine (5); Primary supply system (6); Secondary supply system (7); and Control system (8); The burner (3) includes a combustion chamber (12), a plurality of burner assemblies (10) and a plurality of injectors (11; 111), each of the plurality of burner assemblies having a corresponding reaction zone (Zt) inside the combustion chamber (12), and the plurality of injectors being configured to inject the secondary fluid (F2) downstream of the reaction zone (Zt) of the burner assembly (10). The method includes: Primary fuel (F1) is supplied to the burner assembly (10) and secondary fluid (F2) is supplied to the injector, wherein the primary fuel (F1) comprises ammonia and the secondary fluid (F2) comprises air and / or fuel; and The primary supply system (6) is controlled such that the burner assembly (10) converts a first mixture having a first fuel-air equivalence ratio (φ1) greater than 1 in the reaction zone (Zt), and the secondary supply system (7) is controlled such that the secondary fluid has a second fuel-air equivalence ratio (φ2) less than 1.

14. A combustor for a gas turbine engine, comprising: Combustion chamber (12); Multiple burner assemblies (10) are operable using primary fuel (F1) containing ammonia and each has a corresponding reaction zone (Zt) within the combustion chamber (12); as well as Multiple injectors (11; 111) are configured to inject secondary fluid (F2) downstream of the reaction zone (Zt) of the burner assembly (10); The combustion chamber (12) is annular and has a connecting wall (12a), and each burner assembly (10) includes a first burner (15) and a second burner (16), the first burner (15) and the second burner (16) defining a first portion (Zp) and a second portion (Za) of the respective reaction zone (Zt) and arranged coaxially along the axis (B) of the respective burner assembly (10), wherein the first burner (15) surrounds the second burner (16) and the first portion (Zp) of the reaction zone (Zt) is radially outside the second portion (Za).

15. The burner according to claim 14, wherein, The injectors (11; 111) and the burner assembly (10) alternate in the circumferential direction of the combustion chamber (12).

16. The burner according to claim 15, wherein, Each injector (11; 111) has a plurality of nozzles (30; 130) arranged such that the secondary fluid (F2) is injected downstream of the reaction zone (Zt) of the correspondingly adjacent burner assembly (10).

17. The burner according to claim 14, wherein, The burner assembly (10) is in communication with the combustion chamber (12) via the connecting wall (12a), and wherein each injector (11) includes a corresponding tubular body (11a) extending from the connecting wall (12a) along the injector axis (C) toward the interior of the combustion chamber (12).

18. The burner according to claim 17, wherein, Each injector (11) has a first end and a second end, the first end being fixed to the connecting wall (12a) and open to receive the secondary fluid (F2) through the connecting wall (12a), and wherein the nozzle (30) is circumferentially arranged at the second end and configured to inject the secondary fluid (F2) laterally and / or in a direction parallel to the injector axis (C).

19. The burner according to claim 14, wherein, The injector (111) includes a corresponding elongated body (111a) having a trailing edge (111c) and extending transversely to the gas flow passing through the combustion chamber (12) from the inner shell (12b) of the combustion chamber (12) to the outer shell (12c).

20. The burner according to claim 19, wherein, The nozzle (130) is located at the trailing edge (111c) and is configured to inject the secondary fluid (F2) laterally and / or in a direction parallel to the gas flow in the combustion chamber (12).

21. The burner according to claim 19, wherein, The trailing edge (111c) of the injector (111) has a convex angle.

22. The burner according to claim 14, wherein, The combustion chamber (12) is annular and has a connecting wall (12a), and each burner assembly (10) includes a first burner (15) and a second burner (16), the first burner (15) and the second burner (16) defining a first portion (Zp) and a second portion (Za) of the respective reaction zone (Zt) and arranged coaxially along the axis (B) of the respective burner assembly (10), wherein the first burner (15) surrounds the second burner (16) and the first portion (Zp) of the reaction zone (Zt) is radially outside the second portion (Za).

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